BALL SPLINE ROTARY BALL SPLINE STROKE BALL SPLINE BALL SCREW SPLINE

Transcription

1 ROTARY STROKE BALL SCREW SPLINE STRUCTURE AND ADVANTAGES B- TYPES B- ACCURACY B- PRELOAD AND CLEARANCE IN ROTATIONAL DIRECTION B- STRENGTH OF SPLINE SHAFT B- LOAD RATING B- CALCULATION OF DEFLECTION AND DEFLECTION ANGLE OF SPLINE SHAFT B- ALLOWABLE ROTATIONAL SPEED OF SPLINE SHAFT B- LIFE CALCULATION B- OPERATING CONDITIONS B- LUBRICATION B- HOLLOW SPLINE SHAFT B- SPECIAL REQUIREMENTS B- USE AND HANDLING PRECAUTIONS B- MOUNTING B- DIMENSION TABLE B- ROTARY STRUCTURE AND ADVANTAGES B- ACCURACY OF SPR TYPE B- ACCURACY OF SPB TYPE B- PRELOAD AND CLEARANCE IN ROTATIONAL DIRECTION B- HOLLOW SPLINE SHAFT B- SPECIAL REQUIREMENTS B- MOUNTING B- LUBRICATION B- OPERATING CONDITIONS B- APPLICATION EXAMPLES B- DIMENSION TABLE B- STROKE STRUCTURE AND ADVANTAGES B- ACCURACY B- PRELOAD AND CLEARANCE IN ROTATIONAL DIRECTION B- COMPARISON OF DYNAMIC FRICTIONAL RESISTANCE B- USE AND HANDLING PRECAUTIONS B- DIMENSION TABLE B- BALL SCREW SPLINE STRUCTURE AND ADVANTAGES B- PRELOAD B- USE AND HANDLING PRECAUTIONS B- ACCURACY B- SPBR TYPE MOTION PATTERN B- SPBF TYPE MOTION PATTERN B- DIMENSION TABLE B- B-

2 The NB ball spline is a linear motion mechanism utilizing the rolling motion of ball elements that can sustain loads and transfer torque simultaneously. It can be used in a wide variety of applications including robotics and transport type equipment. TYPES TYPES OF SPLINE NUT A wide variety of spline nut designs are available and all spline nuts come with side-seals as a standard feature. Table B- Types of Spline Nut type of nut shape and advantage page STRUCTURE AND ADVANTAGES The NB ball spline consists of a with raceway grooves and a spline nut. The spline nut consists of an outer cylinder (main body), retainer, side rings, and ball elements that is designed and manufactured to achieve a reliably smooth motion. High Load Capacity and Long Travel Life The raceway grooves are machined to a radius close to that of the ball elements. The large ball contact area results in high load capacity and long travel life. Wide Variety of Configurations Spline shaft sizes with diameters from to are available. Several types of Spline nut are available: cylindrical types (SSP/SSPM), and flange types (SSPF/SSPT). Material option of Stainless steel (SUSC or equivalent) is also available. They can be specified to suit various applications. High Accuracy Torque Transmission Due to the effective contact angle between the raceway grooves and the balls, the NB ball spline can transfer large torque. By adjusting preload it is possible to obtain a higher rigidity and a higher positioning accuracy. Ease of Additional Custom Machining Since a round shaft with raceway grooves is used, NB ball s can be easily machined to customized s. High-Speed Motion and High-Speed Rotation The outer cylinder is compact and well balanced, resulting in good performance at high speed. LIGHT WEIGHT and COMPACTNESS The NB ball spline SSP-AM type has a smaller splinenut diameter compared to the conventional SSP type nut on the same shaft diameter. The SSP-AM type is best suited for the chip-mounter head device and the multiaxial applications. Anti-corrosion type is also available. comparison between SSPAM and SSP nut outer dia. % smaller nut length % shorter cylindrical type SSP SSPS SSP-AM SSPS-AM SSPM SSPF SSPFS cylindrical spline nut with key groove with special key nominal diameter: SSP- : SSPS- light and compact nut countersink for fixing (SSPAM) with special key nominal diameter: - cylindrical spline nut without key groove with two lock plates for fixing nominal diameter: - spline nut with flange nominal diameter: SSPF- : SSPFS- P.B- P.B- P.B- P.B- Figure B- Basic Structure of NB Ball Spline outer cylinder side ring with side-seal retainer ball elements SSP Type return cap seal ring outer cylinder steel ball SSP-AM Type flange type SSPT SSPT-AM SSPK-AM SSPTS-AM SSPKS-AM spline nut with a two side cut flange nominal diameter: - light and compact nut with flange nominal diameter: - P.B- P.B- B- B-

3 ACCURACY TYPES OF SPLINE SHAFT Depending on the application requirements, either a ground or a non-ground (coercial grade) is available. Table B- type of shape and advantage The NB ball spline is measured for accuracy at the points shown in Figure B- and categorized as either highgrade (blank) or precision-grade (P). Contact NB for accuracy information on the coercial type ball spline. Figure B- Accuracy Measurement Points spline nut support area part attachment area A A-B B support area part attachment area ground coercial shaft (non-ground) precision ground and precision machined surface finish high precision p o s s i b l e to m a c h i n e e n d s of and surface treatment nominal diameter: - for general industrial use cost effective p o s s i b l e to m a c h i n e e n d s of and surface treatment nominal diameter: - maximum length: (refer to page B-) A-B Table B- Tolerance Relative to Spline Support Area (Max.) radial runout of part attachment area high-grade precision-grade SSP AM SSP AM SSP AM SSP AM SSP AM SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP SSP L SSP SSPL A-B A-B A-B A-B Note: The support area is the portion where, for example, radial bearings are attached in order to support the. The part attachment area is the portion to which other parts, such as gears are attached. Tolerance of Spline Shaft Groove Torsion (Max.) The groove torsion is indicated per, arbitrarily set as the effective length of the section. Table B- Tolerance of Spline Shaft Groove Torsion(Max.) type of shaft ground shaft accuracy grade high precision(p) / / perpendicularity of the end of the section (when grinding is requested on the drawing) high-grade precision-grade unit: perpendicularity of the flange high-grade precision-grade SSP SSP SSP SSP SSP SSP B- B-

4 STRENGTH OF SPLINE SHAFT Table B- Radial Runout of Outer Surface of Spline Nut Relative to Spline Shaft Support Area (Max.) unit: total length of () greater or less than,,,,,,, SSP SSPAM SSPA, A maximum length: Please contact NB for shaft lengths exceeding. PRELOAD AND CLEARANCE IN ROTATIONAL DIRECTION * * Both the clearance and preload are expressed in terms of clearance in the rotational direction. The preload is categorized into three different levels: standard, light (T), and medium (T). A preload cannot be specified with the coercial grade. Table B- Preload and Clearance in Rotational Direction unit: Table B- Preload and Operating Condition standard light (T) medium (T) preload preload symbol operating conditions SSP AM minute vibration is applied. SSP AM a precise motion is required. standard blank SSP AM + a torque in a given direction is SSP AM applied. SSP AM SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP SSP L SSP SSPL precision grade SSPAM SSP SSP SSPAM SSPAM precision grade precision grade SSP SSPAM precision grade B- SSPA SSPA SSPA light precision grade medium SSPA SSPA T T precision grade SSPA SSPA precision grade SSPA SSP SSPL highgrade highgrade highgrade highgrade highgrade highgrade highgrade highgrade highgrade precision grade SSP SSPL precision grade slight vibration is applied. slight torsional load is applied. cyclic torque is applied. shock/vibration is applied. over-hang load is applied. torsional load is applied. Frictional resistance may be affected by preload. The ball spline has larger load ratings compared to ball bush. Also, the ball spline can sustain radial load, moment (bending moment) and torque (twisting moment) at the same time. Thus, it is necessary to consider the strength of ball. Using the following equations, select the size of ball Figure B- Bending Moment spline. Bending Moment Only σ M Z () M: bending moment σ: permissible bending stress of (N/ ) M: bending moment onto (N ) Z: modulus of section( ) (refer to Table B- on page B-) Twisting Moment Only τa T ZP Ta: permissible twisting stress of (N/ ) T: twisting moment onto (N ) Zp: polar modulus of section( ) (refer to Table B- on page B-) Bending Moment and Twisting Moment Combined Calculate equivalent bending moment (Me) by using equation ().Then, substitute Me into equation () for shaft size selection. Me: equivalent bending moment(n ) M: bending moment onto T: twisting moment onto Rigidity of Spline Shaft The rigidity of is expressed in the torsional angle (θ) caused by twisting moment. For high accuracy smooth motion, it is necessary to keep the torsional angle within. per,. T L θ= G IP π Rigidity=. () Me= {M+ (M +T )} () (), L θ:torsional angle( ) T: twisting moment onto (N ) L: length() G: shearing modulus(suj). (N/ ) (SUS). (N/ ) IP: polar moment of inertia of area( ) (refer to Table B- on page B-) θ () B- Figure B- Twisting Moment T: twisting moment Figure B- Deformation of Spline Shaft by Twisting Moment L θ

5 CALCULATION OF DEFLECTION AND DEFLECTION ANGLE OF SPLINE SHAFT Table B- Cross-sectional Characteristics of Spline Shaft I Z IP moment of inertia modulus of polar moment of of area section inertia of area SSP... SSP... SSP... SSP SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP SSP L SSP SSPL SSP SSP SSP SSP SSP SSP SSP AM SSP AM SSP AM SSP AM SSP AM basic dynamic load rating basic static load rating vertical horizontal vertical horizontal LOAD RATING The load rating for SSP-AM type depends on the direction of load. Table B- LOAD RATING SSPAM C. C C. C SSPAM AM C. C C. C B- ZP C=/EI polar modulus of section SUJ SUSC /N Figure B- Load Direction load in vertical direction load in horizontal direction SSPAM load in vertical direction load in horizontal direction SSPAMAM The following formulas are used to obtain the deflection and its angle of the ball. Typical conditions are listed in Table B-. Table B- Formulas for Calculating Deflection and Deflection Angle support formula for deflection formula for deflection angle method support support fixed fixed support support fixed fixed support support fixed fixed fixed free fixed free support support fixed fixed δmax δmax δmax δmax δmax δ δmax δ δmax δmax a i i a l/ l/ P P l/ i l/ i P l P l uniformly distributed load p l uniformly distributed load p l b l b l l l l l Mo Mo i a P a P P uniformly distributed load p i i i δmax i i δmax δmax δmax δmax= Pl EI =Pl C δmax= δmax= pl δmax= Pl EI = Pl C EI = pl EI = i= Pl EI =Pl C δ: deflection at the concentrated load point( )δmax: maximum deflection( )i: deflection angle at the concentrated load point(rad)i: deflection angle at the support point(rad)mo: moment(n )P: concentrated load(n)p: uniformly distributed load(n/ )a,b: concentrated load point distance( )l: span( )I: moment of inertia of area( )(refer to Table B- on page B-) E: modulus of longitudinal elasticity(suj). (N/ )(SUS). (N/ )C: /EI(/N ) pl C pl C δ= Pa b =Pa EI + b C a + a δmax= Pa l =Pa EI l C a a δ= Pa a =Pa EI a C l l δmax= Pa =Pa EI + b C a + b a δmax= Pl EI =Pl C δmax= pl EI =pl C δmax= Mol = Mol EI C δmax= Mol = Mol EI C B- i= i= i= i= pl EI =pl C i= i= Pab EI =PabC i= Pa(a+b) =Pa(a+b)C EI i= Pa b Pa bc = EIl l i= i= Pl EI =Pl C i= i= pl EI =pl C i= i= Mol EI =MolC i= Mol EI =MolC i= Mol EI =MolC i=

6 ALLOWABLE ROTATIONAL SPEED OF SPLINE SHAFT RATED LIFE CALCULATION When the rotational speed is increased and approaches the resonant frequency, the spline shaft is disabled from further operation. This speed is called the critical speed and can be obtained by the following equations. In order to leave a sufficient safety margin, the allowable operating speed should be set at about % of the calculated value. Using the following equations, select the size of ball. First, calculate Id and A by equation () and () then, substitute the values into equation (). NC= π L Nc: critical speed (rpm) L: support distance () E: modulus of longitudinal elasticity (SUJ). (N/ ) (SUS). (N/ ) γ: density (SUJ). (kg/ ) (SUS). (kg/ ) Id: Minimum Moment of Inertia of Area ( ) Id= d: maximum machined-down diameter with no spline grooves left(refer to Table B-) A: Minimum Cross-sectional Area of the Spline Shaft ( ) A= π d π d λ E Id γ A λ: coefficient of mounting method (refer to Figure B-) fixed-free λ=. supported-supported λ=. fixed-supported λ=. fixed-fixed λ=. () () () d: maximum machined-down diameter with no spline grooves left(refer to Table B-) Table B- Spline Shaft Profile d: maximum diameter with no spline grooves left SSP SSP SSP SSP SSP SSP SSP SSP SSP SSP SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP SSP L SSP SSPL SSP AM SSP AM SSP AM SSP AM SSP AM d: maximum diameter with no spline grooves left Figure B- Mounting Method fixedfree fixed supportedsupported supported :support distance fixedsupported fixed fixedfixed fixed :support distance λ=. λ=. :support distance λ=. :support distance λ=. d:maximum diameter with no spline grooves left free supported supported The maximum diameter (d) is recoended as the shaft diameter of the support area leaving no spline grooves after end-machining. B- fixed When the ball elements are used as the rolling elements in ball splines, the following equations are used to calculate the life of ball spline: For radial load L= ( fc fw C P ) For torque load L= ( fc fw CT T ) L: rated life (km) fc: contact coefficient fw: load coefficient C: basic dynamic load rating (N) P: applied load (N) CT: basic dynamic torque rating (N m) T: applied torque (N m) * Refer to page Eng- for the coefficients ** The load rating of the coercial spline is approximately % of the standard ball spline. Lh= L ls n Lh: life time (hr) ls: stroke length (m) L: rated life (km) n: number of cycles per minute (cpm) OPERATING CONDITIONS The performance of the ball spline is affected by the operating conditions of the application. The operating conditions should, therefore be carefully taken into consideration. Dust Prevention Foreign particles or dust in the ball spline nut affects the motion accuracy and shortens the life time. Standard seals will perform well against dust prevention under normal operating conditions; however, in a harsh environment, it is necessary to attach bellows or protective covers. (refer to Figure B-) Operating Temperature Since the retainer is made of resin, the operating temperature should never exceed. B- Figure B- Radial Load and Torque Load radial load torque load moment Figure B- Example of Dust Prevention bellows cover

7 LUBRICATION USE AND HANDLING PRECAUTIONS The spline nut is prelubricated with lithium soap based grease prior to shipment for iediate use. Please relubricate with a similar type of grease periodically depending on the operating conditions. Low dust generation grease is available from NB standard grease. (refer to page Eng-) The NB spline nut has seals as standard. The seals work well to contain the grease inside the nut especially for the ground shaft, since the seal shape approximates the profile. HOLLOW SPLINE SHAFT Figure B- Example of Lubrication Mechanism NB provides hollow shafts. It can be used for running cable, air piping, and weight reduction. Table B- shows a list of recoended inner diameter for hollow (SUJ). Table B- Recoended Inner Diameter for Hollow Spline Shaft part number SSP SSP SSP SSP SSP A SSP A SSP A SSP A SSP AM SSP AM SSP AM SSP AM SSP AM shaft diameter inner diameter d cross-sectional coefficient Z.,,,,... second moment of inertia I...., SPECIAL REQUIREMENTS..... Based on customer drawings and requirements NB offers shaft-end machining, spline nut machining, surface treatment, etc. Please contact NB for special requirements. d Figure B- Example of Shaft-end Machining NB ball spline must be handled with care as it is a precise component. Please note the following points. A Set of Spline Nut and Spline Shaft Figure B- NB mark Alignment The ball spline's accuracy and preload is guaranteed when spline nut and shaft are aligned as shown in Figure B-. Please make sure to align the NB align marks when reinserting the shaft. When inserting the into the spline nut, NB JAPAN ensure that the ball elements do not drop out. This NB JAPAN is done by aligning the raceway grooves of the shaft with the rows of ball elements and the seal lip of the nut. Then, carefully insert the through the spline nut. In case that the nut is preloaded, please exercise additional care. Fit between Spline Nut and Housing Table B- Fit for the Spline Nut A transition fit is used for the SSP/SSPM-type spline nut and its housing bore to minimize the clearance. If high accuracy is not required, then a clearance fit can be used. Regarding the SSPT/SSPF type spline nut, for a light load and little torque application a hole slightly larger than the outer diameter of the nut can suffice. The mounting surface for the flange influences the perpendicularity and parallelism. Please make sure that the accuracy of the mounting surface is correct. type of spline nut SSP SSP-AM SSPM clearance fit H transition fit J Figure B- Insertion of Spline Nut into Housing Insertion of Spline Nut When inserting a spline nut into the housing, use a jig like the one shown in Figure B-. Carefully D insert the nut so as to not hit the side ring and seal. Table B- Recoended Jig Dimensions unit: jig D d D d SSP SSP SSP SSP SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP SSP L SSP SSPL SSP SSP SSP SSP SSP SSP SSP AM SSP AM SSP AM SSP AM SSPAM d Excessive Moment One spline nut can sustain high moments, however, excessive moment makes the spline nut unbalanced and unstable during motion. Please use more than one spline nut for high moment or high accuracy applications. B- B-

8 MOUNTING Mounting of SSP Type Examples of installing the SSP type are shown in Figures B- and B-. Figure B- Using a Retaining Ring Figure B- Using a Push Plate Mounting of SSPAM Type Example of installing the SSAM type are shown in Figure B-. M screw is used for mounting. In process of mounting, please be careful with spline nut. Figure B- Using SSPAM Lock Plates Key The SSP type spline nut comes with a key shown in Figure B-. Figure B- Key for SSP Type Mounting of SSPM Type Examples of installing the SSPM type are shown in Figures B-,, and. Figure B- Using F Type Lock Plates (R) C Table B- Major Dimensions of Key SSP SSP SSP SSP SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP SSP L SSP SSPL SSP SSP SSP SSP SSP SSP... a / h / L. C F Type Lock Plate (Standard Plate) The lock plate shown in Figure B- is provided with the SSPM spline nut. Material: SUSCSP Table B- F Type Lock Plate part number FP FP FP K... G... t... R... applicable spline nut SSPM SSPM SSPM Figure B- F Type Lock Plate K G ー R Figure B- Using LP Type Lock Plates t SSP AM SSP AM SSP AM SSP AM For SSPS and SSP AM type, the material of key is stainless steel. B- B-

9 LP Type Lock Plate (Optional Plate) The LP type lock plate is also available for purchase with the SSPM spline nut. Material: SUSCSP Figure B- LP Type Lock Plate Mounting of SSPF Type Examples of installing the SSPF type are shown in Figure B-. Figure B- Examples of installing SSPF Type E. ー R K (G) (.) X t Y B. B. -C. or more GM ー M When using the LP type lock plate, please machine the housing as shown above. Table B- LP Type Lock Plate part number LP LP LP K... lock plate major dimensions G... t... R X... Y... machined housing dimensions B... E... GM... M M. M M applicable spline nut SSPM SSPM SSPM Figure B- Using Special Lock Plates () Mounting of SSPT Type Examples of installing SSPT type are shown in Figure B-. Figure B- Examples of installing SSPT Type Figure B- Using Special Lock Plates () B- B-

10 SSP TYPE - Cylindrical Spline Nut - structure example SSP L - - T - - P / CU SSP: standard SSPS: anticorrosion nominal diameter with special accuracy grade blank: high P: precision When two spline nuts are used in close contact. total length nut length blank: standard L: long number of nuts attached to one shaft Note: retainer material is resin. preload symbol blank: standard T: light T: medium standard SSP SSP SSP SSP SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP A SSP SSP L SSP SSPL anti-corrosion SSPS SSPS SSPS SSPS SSPSA SSPSA SSPSA SSPSA D / L.. B.... major dimensions b t / + + L. d basic torque rating dynamic CT static CoT ,,,,,,,,,,,, basic load rating dynamic static C Co kn kn allowable static moment MO.....,,,, MO.,,,,,,,,, mass nut shaft kg kg/m size A A A A A A A A L L SSP SSP SSP SSP SSP SSP SSPS SSPS / SSP type spline nut comes with a key(refer to page B-). / /,,,, ,,,,, kn kgf N m.kgf m B- B-

11 SSP-AM TYPE SSPAM MY C,CO SSPAM MP structure CT,COT D example SSP AM - - T - - P / CU MY SSPAM SSPAM spline nut does not come with seal ring. B (L) SSP AM:standard SSPS AM:anti-corrosion with special accuracy grade blank:high P:precision total length MP When two spline nuts are used in close contact. b C,CO t MY L MP nominal diameter number of nuts attached to one shaft Note:SSP(S)AM does not come with side-seals. Material of return cap is resin. preload symbol blank:standard T:light CT,COT SSPAMAM SSPAM spline nut does not come with any oil hole. B (L) D d (oil hole) major dimensions basic torque rating basic load rating allowable static mass D L B b t L d DS h dynamic static dynamic static moment nut shaft size +. CT CoT C Co MP MY standard anti-corrosion MP MY N m N m N N N m N m g g/ SSP AM SSPS AM AM SSP AM SSPS AM......,.... AM SSP AM SSPS AM....., AM SSP AM SSPS AM ,,.... AM SSPAM SSPSAM.....,,.... AM SSP(S)AM-AM type spline nut come with a key(refer to page B-). Allowable static moment MP and MY are the values when two spline nuts are used on close contact. kn kgf.kgf m B- B-

12 SSPM TYPE - Keyless Spline Nut - structure example SSPM - - T - - P / CU SSPM type with special accuracy grade blank: high P: precision total length When two spline nuts are used in close contact. nominal diameter number of nuts attached to one shaft Note: retainer material is resin. preload symbol blank: standard T: light SSPM SSPM SSPM D / L. F... major dimensions W C A Two F type lock plates per SSPM type spline nut are provided(refer to page B-).... d B.. H... K... G... t... DS / basic torque rating dynamic CT.. static CoT... basic load rating dynamic C kn.. static Co kn... allowable static moment MO... MO mass nut shaft kg... kg/m... size kn kgf N m.kgf m B- B-

13 SSPF TYPE - Flange Type Nut - structure example SSPF - - T - - P / CU SSPF: standard SSPFS: anticorrosion with special accuracy grade blank: high P: precision total length When two spline nuts are used in close contact. nominal diameter number of nuts attached to one shaft preload symbol blank: standard T: light T: medium Note: retainer material is resin. standard SSPF SSPF SSPF SSPFA SSPFA SSPFA SSPFA SSPFA SSPFA SSPFA SSPFA anti-corrosion SSPFS SSPFS SSPFS SSPFSA SSPFSA SSPFSA SSPFSA D / L.. major dimensions Df H P.C.D. d d h W..... d basic torque rating dynamic static CT CoT /......,, /,, basic load rating dynamic static C Co kn kn allowable static moment MO.... MO,,,,, mass nut shaft kg kg/m size A A A A A A A A SSPF SSPF SSPF SSPF SSPF SSPF SSPFS SSPFS / / /,,,, ,,,,, kn kgf N m.kgf m B- B-

14 SSPT TYPE - Two Side Cut Flange Type - structure example SSPT - - T - - P / CU with special accuracy grade blank: high P: precision When two spline nuts are used in close contact. SSPT type nominal diameter number of nuts attached to one shaft total length preload symbol blank: standard T: light Note: retainer material is resin. SSPT SSPT SSPT D / L. Df major dimensions B H P.C.D. d d h W.. d DS / basic torque rating dynamic CT.. static CoT... basic load rating dynamic C kn.. static Co kn... allowable static moment MO... MO mass nut shaft kg... kg/m... size kn kgf N m.kgf m B- B-

15 SSPT-AM TYPE SSPK-AM TYPE Light and Compact Flange Type MY structure example SSPK AM - - T - - P / CU Df C,C P.C.D. -d MP (AM) SSPT AM:standard SSPTS AM:anti-corrosion (AM AM) SSPK AM:standard SSPKS AM:anti-corrosion with special accuracy grade blank: high P: precision total length K SSPTAM SSPTAM spline nut does not come with seal ring. CT,CT H B (L) MY D nominal diameter number of nuts attached to one shaft preload symbol blank: standard T: light Note: Nut material of SSPT-AM and SSPK-AM is stainless steel. Df C,C -d P.C.D. MP -d (oil hole) CT,CT D K SSPKAM AM SSPKAM spline nut does not come with oil groove. HW B (L) major dimensions basic torque rating basic load rating allowable mass D h L B Df K H P.C.D. d W d h dynamic static dynamic static static moment nut shaft size CT CoT C Co MP MY standard anti-corrosion MP MY N m N m N N N m N m g g/ SSPT AM SSPTS AM AM SSPK AM SSPKS AM ,.... AM SSPK AM SSPKS AM......,.... AM SSPK AM SSPKS AM ,,.... AM SSPK AM SSPKS AM.....,,.... AM Allowable static moment MP and MY are the values when two spline nuts are used in close contact. N gf N m gf m B- B-

16 COMMERCIAL structure example SSPF C - - / CU nut shape SSP: cylindrical type SSPF: flange type nominal diameter coercial with special total length number of nuts attached to one shaft major dimensions applicable nut standard length L A,,,,, A,,,,, A,,,,, A,,,,, A,,,,, nominal diameter SSP SSPF.,,,,,,,,,,,,,,,.,,,,,,,,,, Tolerance of total length yes - none total length up to,: JIS B coarse grade total length greater than,: ±. Please specify s when required. Please refer to dimension tables for nut shape and dimensions. When a coercial shaft is used, the load rating of the nut is approximately % of indicated rating in the dimension tables. B- B-

17 ROTARY ROTARY The NB rotary ball spline can be used for both rotational motion and linear motion. The applications include SCARA robots, vertical shaft of assembly equipment, tool changers, and loaders, etc. STRUCTURE AND ADVANTAGES ACCURACY OF SPR TYPE The accuracy of SPR type is measured at the points shown in Figure B-. Figure B- Accuracy Measurement Points support area A-B A A-B rotary ball spline nut A-B A-B B support area A-B The NB Rotary Ball Spline nut consists of a spline nut and a rotating portion using either cross rollers for SPR or balls for SPB. High Accuracy Ball Splines transfer torque and achieve accurate positioning in the linear direction. By adding the rotating portion, Rotary Ball Splines can achieve accurate positioning in the linear and rotational directions. Half the Parts, Reduction in Installation Cost The Spline nut and rotary bearing are combined in order to significantly reduce the number of parts, compared to conventional system. The combination also reduces the housing thickness to a minimum, resulting in light weight and easy installation. Figure B- Structure of SPR type tightening screw for installation flange seal installation flange spline nut side-seal Figure B- Structure of SPB-KP type and SPB type SPB-KP type retainer oil hole for lubrication groove linear portion flange outer ring seal spline nut ball elements side-seal angular contact bearing retainer oil hole for rotary portion marking ball elements When lubricating linear portion, both oil hole linear and rotary can match by aligning the raceway grooves of the shaft with the marking of flange outer ring. B- Compact and High Rigidity(SPR type) The cross rollers are directly attached to the ball spline's outer cylinder, resulting in a compact and light design. SPR type has high rigidity despite its compactness. The tool changer is one typical application. High Rigidity and High Speed(SPB type) SPB type is a combination of a spline nut and angular contact bearings. The rotary portion is a set of angular contact bearings which are aligned in the back-to-back duplex manner. SPB type can bear radial, axial, and moment loads in a well-balanced way, thus best suited to high speed rotational applications. SPB type cross roller elements retainer outer ring spacer flange outer ring spline nut side-seal ball elements seal ball elements angular contact bearing retainer spline nut retainer ball elements part attachment area A-B Table B- Tolerance Relative to Spline Support Area (Max.) A-B part attachment area Note: The support area is the portion where, for example, radial bearings are attached in order to support the. The part attachment area is the portion to which other parts, such as gears are attached. Tolerance of Spline Shaft Groove Torsion (Max.) The groove torsion is indicated per, arbitrarily set as the effective length of the section. SPR SPR SPR SPR SPR SPRA SPRA SPRA SPRA SPRA SPRA SPR SPR SPR SPR SPR SPR radial runout of part attachment area perpendicularity of the end of the section (when grinding is requested on the drawing) Table B- Tolerance of Spline Shaft Groove Torsion (Max.) / unit: perpendicularity of the flange Table B- Radial Runout of Outer Surface of Rotary Spline Nut Relative to Spline Support Area (Max.) unit: total length( ) SPR SPR SPR SPR SPR SPR greater than or less A A A A A A *,,,,, *,, Please contact NB for s exceeding. * SPR shaft Max. length: SPR, SPR Max.length: B- ROTARY

18 ROTARY ACCURACY OF SPB TYPE PRELOAD AND CLEARANCE The accuracy of SPB type is measured at the points shown in Figure B-. Figure B- Accuracy Measurement Points SPB-KP type SPB type support area A-B part attachment area C-D A A-B C-D A-B C A-B support area C-D C-D A-B A part attachment area A-B C D A-B B A-B B D support area A-B A-B A-B part attachment area support area A-B part attachment area Note : The support area is the portion where, for example, radial bearings are attached in order to support the. The part attachment area is the portion to which other parts, such as gears, are attached. and indicate radial runout during rotational motion. Tolerance of Spline Shaft Groove Torsion(Max.) The groove torsion is indicated per, arbitrarily set as the effective length of the section. Table B- Tolerance of Angular Contact Bearing Rotation(Max.)unit: lateral runout of radial runout of flange mounting side outer ring highgradgrade(pgrade grade(p) precision- SPB KP SPB KP SPB KP SPB KP SPBKP, SPBKP, SPBKP, Table B- Tolerance of Spline Shaft Groove Torsion(Max.) accuracy grade high / precision(p) / Table B- Tolerance Relative to Spline Support Area(Max.) unit:μ m radial runout of part attachment area perpendicularity of the end of the section (when grinding is requested on the drawing) perpendicularity of the flange high-grade precision-grade(p) high-grade precision-grade(p) high-grade precision-grade(p) SPB KP SPB KP SPB KP SPB KP SPBKP, SPBKP, SPBKP, Table B- Radial Runout of Spline Nut Relative to Spline Support Area(Max.) unit: size total length ( ),, greater than or less highgrade grade(p) grade high- grade(p) grade high- grade(p) grade high- grade(p) grade high- grade(p),,,,, **,, *SPB, KP, and KP shaft maximum length :, Please contact NB for s exceeding,. The amount of clearance and preload for the spline portion and the cross roller portion are expressed in terms of the clearance in the rotational direction and the clearance in the radial direction, respectively. Three levels of preload are available: standard, light (T), and medium (T). Table B- Preload and Clearance in Rotational and Radial Direction unit: Table B- Preload and Clearance in Rotational Direction (Linear Motion) unit: standard light (T) medium (T) SPR + SPR SPR SPR + SPR SPRA SPRA SPRA + linear SPRA motion SPRA + SPRA SPR SPR + SPR SPR SPR + SPR rotational motion SPR SPR + HOLLOW SPLINE SHAFT NB provides hollow shafts. It can be used for running cable, air piping, and weight reduction. Table B- shows a list of recoended inner diameter for hollow (SUJ). Table B- Recoended Inner Diameter for Hollow Spline Shaft outer diameter inner diameter d second moment of inertia I SPECIAL REQUIREMENTS cross-sectional coefficient Z SPR SPB KP.. SPR SPB KP. SPR SPB KP. SPR SPB KP, SPR SPBKP,, SPRA SPBKP,, SPRA SPBKP,,, NB provides customization such as shaft-end machining, spline nut machining, and surface treatment per customer requests.please contact NB for the inner diameter of SPR SPR. standard light(t) medium(t) SPB KP SPB KP SPB KP SPB KP SPBKP, ~ + - ~ + - ~ - ~ - - ~ - SPBKP, SPBKP, - ~ + - ~ - - ~ - Please contact NB for other than preload standards above. Table B- Preload and Operating Conditions preload standard symbol blank operating conditions minute vibration is applied. a precise motion is required. light T moment is applied in a given direction. light vibration is applied. light torsional load is applied. medium T cyclic torque is applied. shock/vibration is applied. over-hang load is applied. torsional load is applied. Frictional resistance may be affected by preload. d Figure B- Examples of Shaft-end Machining ROTARY B- B-

19 ROTARY MOUNTING LUBRICATION The flange attachment screws of SPR type have been pre-adjusted for smooth rotary movement and should never be loosened. Shock loading to the flange assembly should be avoided as this can degrade the accuracy of movement and deteriorate the overall performance. The spacer of SPB type is properly adjusted to produce the best preload condition. Shock loading to the spacer should be avoided as this can change the preload condition and deteriorate the accuracy. Please fix the mounting screws diagonally. The recoended torque values for medium-hardness steel screws are listed in Table B-. Table B- Recoended Torque mounting screw recoended torque M. M.. (for alloy steel screw) M. M. M unit:n m M M... SPR Type When the flange of SPR type is to be used with a faucet joint (as shown in Figure B-) the housing bore should be machined to a of H and to a minimum depth of % of the flange thickness. If only a light load is applied to the SPR in operation, the flange can be used without a pilot end. SPB-KP Type The housing bore for the SPB-KP type should be matched to a of H and keep enough depth ( as shown in Figure B-) so that the outer ring is inside the housing. Figure B- SPR type Mounting Method.H minimum D H greater than D+(..) Figure B- SPB-KP type Mounting Method flange outer ring housing Since NB rotary ball spline nuts are equipped with seals at both the spline portion and the rotational portion, the lubricant is retained for an extended period of time. The spline nut is prelubricated with lithium soap based grease prior to shipment for iediate use. Please relubricate with a similar type of grease periodically depending on the operating conditions. Low dust generation grease is available from NB standard grease. (refer to page Eng-) However, an oil lubricant is recoended for high-speed applications. A grease fitting or machining oil holes is optional (Figure B--), please contact NB for details. SPR Type A grease fitting for rotational portion and machining oil hole for spline portion are optional. Figure B- Example of Installed Grease Fitting grease fitting SPB-KP Type Lubrication is done through oil hole on the outer ring. It is applied the spline portion and the cross roller portion simultaneously. Figure B- SPB-KP type Oil Hole Figure B- SPR type Oil Hole Oil Hole SPB Type Rotational portion has an oil hole as a standard. For lubrication, it is recoended to mount a grease fitting or oil hole to housing. Machining oil hole for spline portion is available. Please contact NB. Figure B- SPB type Oil Hole angular contact bearings oil hole ROTARY SPB Type The housing bore for the SPB type should be machined to a of H and contain enough depth so that the outer ring is inside the housing. If not, the outer ring may fall off. Figure B- SPB type Mounting Method outer ring housing flange outer ring grease fittting oil hole lubrication groove grease fitting angular contact bearings oil hole spline portion oil hole option lubrication groove Insertion of Spline Shaft When inserting the into the rotary ball spline nut, ensure that the ball elements do not drop out. This is done by aligning the raceway grooves of the shaft with the rows of ball elements and seal -lip of the nut. Then, carefully insert the through the spline nut. B- B-

20 ROTARY OPERATING CONDITIONS APPLICATION EXAMPLES The performance of the rotary ball spline is affected by the operating conditions of the application. The operating conditions should therefore be carefully taken into consideration. Operating Temperature Resin retainers are used in the rotary ball spline, since the operating temperature should never exceed. Dust Prevention Foreign particles or dust in the rotary ball spline nut affect the motion accuracy and shorten the lifetime. Standard seals will perform well for dust prevention under normal operating conditions; however, in a harsh environment, it is necessary to attach bellows or protective covers. Figure B- NB mark Alignment SPR Type SPB-KP Type SPB Type ROTARY B- B-

21 ROTARY SPR TYPE structure SPR type example SPR - - T - / CU with special total length ROTARY nominal diameter number of nuts attached to one shaft Note: retainer material is resin. preload symbol blank: standard T: light T: medium SPR SPR SPR SPR SPR SPRA SPRA SPRA SPRA SPRA SPRA SPR SPR SPR SPR SPR SPR D major dimensions D L P S P.C.D... /.. M M. M M M M M M M M M M M M M M M Please contact NB for the grease fitting and relubrication method. h. I major dimensions of cross roller bearing H D P d G F θ P.C.D... / M M M M M M. M. M. M. M. M. M. M. M. M. M. M DS / / / ball spline basic torque rating basic load rating dynamic static dynamic static CT CoT C Co kn kn..,,....,, ,,,, Maximum revolutions for grease lubrication. Contact NB for further information in case oil lubrication is required. cross roller bearing basic load rating dynamic CR kn static CoR kn maximum revolutions rpm,,,,, allowable static moment MO...., mass nut shaft kg kg/m size A A A A A A kn kgf N m.kgf m B- B-

22 ROTARY SPB-KP TYPE structure example SPB KP - - T - - P / CU SPB KP type nominal diameter number of nuts attached to one shaft with special accuracy grade blank:high P:precision total length preload symbol for linear portion blank: standard T: light T: medium ROTARY major dimensions major dimensions of angular contact bearing rotary ball spline angular contact bearings allowable basic torque rating basic load rating basic load rating maximum static mass D h D L P S h D g D H B B P d W d dynamic static dynamic static dynamic static revolutions moment nut shaft size P.C.D. P.C.D. CT CoT C Co CR CoR Mo kn kn kn kn rpm kg kg/m SPB KP M ,... SPB KP M ,... SPB KP - M ,... SPB KP M ,... SPB KP M ,. SPB KP. - M ,.. SPB KP - M ,.. Maximum revolutions for grease lubrication. B- B-

23 ROTARY SPB TYPE structure example SPB - - T - - P / CU SPB type nominal diameter number of nuts attached to one shaft with special accuracy grade blank:high P:precision total length preload symbol blank: standard T: light T: medium ROTARY SPB SPB SPB major dimensions L P S P.C.D. Dh.. / M M M h major dimensions of angular contact bearing D D H B B P d P.C.D.... rotary ball spline DS basic torque rating basic load rating dynamic static dynamic static CT CoT C Co N m N m kn kn / angular contact bearings basic load rating maximum dynamic static revolutions CR CoR rpm kn kn......,,, allowable static moment kg... Maximum revolutions for grease lubrication.(please contact NB in case of oil lubrication.) kn kgf N m.kgf m MO N m mass nut shaft kg/m.. size B- B-

24 STROKE STROKE The NB stroke ball spine SPLFS type is a highly accurate linear motion bearing with a limited stroke, to which both radial load and torque can be applied at the same time. It operates with extremely low dynamic friction. ACCURACY The accuracy of the NB stroke ball spline is measured at the points shown in Figure B-. Figure B- Accuracy Measurement Points support area part attachment area A stroke ball spline nut A-B B support area part attachment area STRUCTURE AND ADVANTAGES The NB stroke ball spline consists of a nut and a shaft both with raceway grooves. The flanged spline nut consists of an outer cylinder, a retainer, side-rings, and ball elements. Since the retainer in the nut is equipped with ball pockets, the ball elements do not contact each other, which allows for a smooth linear motion. The stroke is limited since the retainer is a non-circulating type. For normal operation, it is recoended to consider % of the maximum stroke shown in the dimension table as an actual stroke length. Extremely low Dynamic Friction and Low Noise The rolling elements are separated by the ball pockets so that they do not contact each other. The stroke length is limited, but extremely low dynamic friction and low noise are realized because the rolling elements do not circulate. Compact-Size With the nut about % smaller than those of conventional ball splines, it contributes to space saving. Figure B- Structure of SPLFS type All Stainless Steel Type Since all the components are made of stainless steel, this stroke ball spline has an excellent corrosion resistance and heat resistance (operating temperature: ー to ). It is ideal for clean room or vacuum applications. Lubrication A lubricant groove and two lubrication holes are provided on the outer surface of the nut, which allows for an easy designing of lubricant replenishment. A-B A-B Table B- Tolerance Relative to Spline Support Area (Max.) A-B A-B Note: The support area is the portion where, for example, radial bearings are attached in order to support the. The part attachment area is the portion to which other parts, such as gears are attached. Tolerance of Spline Shaft Groove Torsion (Max.) The groove torsion is indicated per, arbitrarily set as the effective length of the section. SPLFS SPLFS SPLFS SPLFS SPLFS radial runout of part attachment area perpendicularity of the end of the section A-B Table B- Tolerance of Spline Shaft Groove Torsion (Max.) / unit: perpendicularity of the flange STROKE side-ring outer cylinder ball elements retainer Table B- Radial Runout of Outer Surface of Spline Nut Relative to Spline Support Area (Max.) unit: total length( ) greater than or less SPLFS SPLFS SPLFS * *,,,,, * SPLFS maximum shaft length: B- B-

25 STROKE PRELOAD AND CLEARANCE USE AND HANDLING PRECAUTIONS Preload and clearance are expressed in terms of clearance in the rotational direction. For the SPLFS type, only the standard preload is available as shown in Table B-. Please contact NB if a special preload is required. Table B- Preload and Clearance in Rotational Direction unit: standard SPLFS SPLFS SPLFS SPLFS SPLFS COMPARISON OF DYNAMIC FRICTIONAL RESISTANCE Figure B- Comparison of Dynamic Friction.. standard preload without load without lubricant measuring speed:./s SSPA SPLFS Dust Prevention Since the stroke ball spline is designed and manufactured for operation with an extremely low dynamic frictional resistance, seals that increase frictional resistance are not equipped as a standard feature. Please contact NB for a special requirement of seals. For use under harsh conditions, the stroke ball spline should be protected using bellows and protective covers. Maximum Stroke The maximum stroke in the dimension table is the stroke limit. Retainer Slippage If the stroke ball spline is used at a high speed or with a vertical shaft, or under an asyetric load or oscillation, a retainer slippage may occur. For general operation, it is recoended to consider % of the maximum stroke length shown in the dimension table as the stroke length. To prevent the retainer slippage, it is recoended to conduct a full-stroke movement of the nut whenever necessary in order for the retainer to be relocated to the center. STROKE dynamic friction (N).. travel distance () B- B-

26 STROKE SPLFS TYPE Two Side Cut Flange Type structure example SPLFS - - / CU SPLFS type When two spline nuts are used in close contact. STROKE nominal diameter number of nuts attached to one shaft with special total length SPLFS SPLFS SPLFS SPLFS SPLFS maximum stroke D D.. L. E..... Df.. major dimensions H B P.C.D. A F S..... W..... d... DS / basic torque rating dynamic CT..... static CoT.... basic load rating static Co dynamic C kn..... kn.... allowable static moment MO..... MO mass nut shaft g... kg/m.... size kn kgf N m.kgf m B- B-

27 BALL SCREW SPLINE STRUCTURE AND ADVANTAGES The NB Ball Screw Spline consists of a highly accurate and highly rigid Ball Screw nut and Ball Spline nut attached to the ball screw which has a screw groove and spline grooves. SPBR type has a Rotary Ball Screw nut and Rotary Ball Spline nut. Rotary Ball Screw nut is an integration of ball screw nut and angular contact bearings. Rotary Ball Spline nut is an integration of ball spline nut and angular contact bearings. SPBF type has a Rotary Ball Screw nut and a Ball Spline nut. A single axis of the NB Ball Screw Spline can provide positioning, linear and rotary motion as well as combined spiral motion. The typical applications are SCARA robot, assembly machine, loader, etc. Figure B- Structure of SPBR type, SPBF type SPBR type angular contact bearings outer ring flange outer ring spacer seal pulley centering supporter return cap ball screw PRELOAD angular contact bearings flange outer ring outer ring spacer seal side-seal ball screw nut SPBF type The preload is properly adjusted for the ball screw nut, spline nut, and angular contact bearings. Please contact NB for preload. USE AND HANDLING PRECAUTIONS spline nut spline nut retainer steel ball steel ball for rotation angular contact bearing retainer angular contact bearings outer ring flange outer ring spacer seal pulley centering supporter return cap ball screw steel ball for rotation angular contact bearing retainer ball screw nut SSPF type steel ball for rotation angular contact bearing retainer Please do not adjust the spacer. The spacer is adjusted to provide a proper spacing for the best preload condition. Please do not remove the Rotary Ball Screw nut from the shaft. There is no ball-retainer in the Rotary Ball Screw nut. Please use the pulley centering supporter when attaching the pulley to the return-cap. B- ACCURACY The NB Ball Screw Spline is measured for accuracy at the points shown in Figure B-. Figure B- Accuracy Measurement Points SPBR type support area part attachment area A-B A-B SPBF type support area part attachment area A A - A-B - A-B - C-D - C-D - A-B - E-F - E-F A-B A-B C D E F rotary ball screw nut ball screw rotary ball spline nut - A-B - A-B - C-D - C-D - A-B A-B A-B - A-B A-B A-B C D rotary ball screw nut ball screw spline nut Note: The support area is the portion where, for example, radial bearings are attached in order to support the. The part attachment area is the portion to which other parts, such as gears, are attached. and indicate radial runout during rotational motion. Table B- Tolerance of Spline Shaft Groove Torsion (Max.) / The groove torsion is indicated per, arbitrarily set within the effective length of the spline shaft section. Table B- Tolerance Relative to Spline Support Area (Max.) perpendicularity of the end of the spline radial runout of shaft section part attachment area (when grinding is requested on the drawing) SPBR,SPBF SPBR,SPBF SPBR,SPBF Table B- Radial Runout of Outer Surface of Rotary Spline Nut Relative to Spline Shaft Area (Max.) unit: lateral runout of radial runout of part flange mounting side outer ring number SPBR SPBR SPBR B- - A-B B B support area part attachment area support area part attachment area Table B- Grade of Ball Screw Groove C Applied to lead angle accuracy only perpendicularity of the flange unit: Table B- Radial Runout of Spline Nut Relative to Spline Support Area (Max.) unit: ball screw :SPBR,SPBF total length() - -,- greater than or less,,,

28 SPBR TYPE MOTION PATTERN One set of SPBR type can handle linear, rotational, and spiral motion. SPBF TYPE MOTION PATTERN SPBF type can handle linear motion. SPBR type Mtn Pattern Setting clockwise as normal (looking down from above) SPBF type Mtn Pattern Setting clockwise as normal (looking down from above) N(reverse) N(normal): ball screw nut pulley rotation (around) rotary ball screw nut N(reverse) N(normal): ball screw nut pulley rotation (around) rotary ball screw nut rotary ball spline nut spline nut N(reverse) N(normal): spline nut pulley rotation (around) ball screw ball screw motion.up down.rotation.spiral ball screw nut N (normal) N (reverse) (normal) (reverse) N (normal) N (reverse) input N=N N=N spline nut (normal) (reverse) N (normal) N (reverse) N (normal) N (reverse) motion direction output revolution (rotational direction) L:travel distance [] R:ball screw lead [] N:ball screw nut pulley rotation (around) N:ball spline nut pulley rotation (around) B- travel distance (linear direction) L=N R (up) L=N R (down) L=N R (down) L=N R (up) in case of N(±N)> N (normal) N (reverse) N (normal) N (reverse) (down) N L=(N(±N)) R in case of N(±N)< (normal) (up) in case of N(±N)> (down) N L=(N(±N)) R in case of N(±N)< (reverse) (up) motion.up down input ball screw nut motion direction L:travel distance [] R:ball screw lead [] N:ball screw nut pulley rotation (around) N (normal) N (reverse) B- output travel distance (linear direction) L=N R (up) L=N R (down)

29 SPBR TYPE structure example SPBR - / CU SPBR type with special nominal diameter Note: retainer material is resin. ball screw total length ROTARY BALL SCREW NUT SPBR SPBR SPBR major dimensions D h D H L P θ S f Te D P.C.D.. M + M / M major dimensions of angular contact bearings D H B B P P.C.D.. d... ball screw lead root diameter Dr... ball screw angular contact bearings moment of moment of basic load rating basic load rating inertia inertia for dynamic static dynamic static maximum for the nut the ball Ca Coa CaR CoaR revolutions screw shaft kn kn kn kn rpm kg cm kg cm / ,,, mass ball screw nut maximum nut shaft revolutions size based on Dm N kg kg/m rpm......,,, ROTARY NUT SPBR SPBR SPBR h.. D h / major dimensions L P P.C.D. S M M M f major dimensions of angular contact bearings D D H B B P P.C.D. d... ball spline basic torque rating basic load rating dynamic static dynamic static CT CoT C Co kn kn angular contact bearings basic load rating dynamic static maximum CR CoR revolutions kn kn rpm..,..,.., allowable static moment Mo N m moment of inertia kg cm... mass nut kg... Please select the smallest maximum revolutions (rpm) in case that more than one portion rotate at the same time. Maximum revolutions for grease lubrication. Moment of inertia is calculated excluding the angular contact bearings. B- B-

30 SPBF TYPE structure example SPBF - / CU SPBF type with special nominal diameter ball screw total length ROTARY BALL SCREW NUT SPBF SPBF SPBF major dimensions major dimensions of angular contact bearings D h D H L P θ S f Te D D H B B P d P.C.D. P.C.D.. M.. + M. / M. ball screw lead root diameter Dr... ball screw angular contact bearings moment of moment of basic load rating basic load rating inertia inertia for dynamic static dynamic static maximum for the nut the ball Ca Coa CaR CoaR revolutions screw shaft kn kn kn kn rpm kg cm kg cm / ,,, mass ball screw nut maximum nut shaft revolutions size based on Dm N kg kg/m rpm......,,, NUT SPBF SPBF SPBF D h L. /. major dimensions D H P P.C.D. d d h W.. d basic torque rating dynamic static CT CoT basic load rating dynamic static C Co kn kn allowable static moment Mo N m moment of inertia kg cm... mass nut kg... Please select the smallest maximum revolutions (rpm) in case that more than one portion rotate at the same time. Maximum revolutions for grease lubrication. Moment of inertia is calculated excluding the angular contact bearings. B- B-