STROKE BUSH STROKE BUSH STRUCTURE AN AVANTAGES E- AOWABE SPEE FOR COMBINE ROTATION AN STROKE MOTION E- RATE OA AN RATE IFE E- FIT E- USE AN HANING PRECAUTIONS E- IMENSION TABE E- SRE SERIES STRUCTURE AN AVANTAGES E- RATE OA AN RATE IFE E- APPICATION EXAMPES E-4 USE AN HANING PRECAUTIONS E- FET SEA E- IMENSION TABE E- RK TYPE STRUCTURE AN AVANTAGES E- IFE CACUATION E- IMENSION TABE E-7 STROKE BUSH E-
STROKE BUSH STROKE BUSH The NB stroke bush is a linear an rotational motion mechanism utilizing the rotational motion of ball elements between an outer cyliner an a shaft. It is compact an can withstan high loaing. The retainer is mae of a light metal alloy with high wear resistance. Smooth motion is achieve uner high-spee an high-acceleration conitions. Although the linear motion is limite to a specific stroke length, the combine rotation an stroke motion is achieve with very little frictional resistance. The NB stroke bush can be conveniently use in a variety of applications. STRUCTURE AN AVANTAGES The retainer in the NB stroke bush positions the ball elements in a zigzag arrangement. The inner surface of the outer cyliner is finishe by precision grining, resulting in smooth motion of the ball elements. Each of the ball elements is hel in a separate hole an smooth motion is achieve for both rotational motion an linear motion. The retainer moves half the length of the linear motion, therefore, the stroke length is limite to approximately twice the length the retainer can travel within the outer cyliner. High Precision High-carbon chromium bearing steel is use for the outer cyliner. It is heat treate an groun to achieve high rigiity an accuracy. Figure E- Structure of SR Stroke Bush outer cyliner seal linear motion Ease of Mounting an Replacement The highly accurate fabrication of the NB stroke bush results in uniform imensions, facilitating parts replacement an housing fabrication. ight Weight an Space Saving The use of an aluminum alloy for the retainer an the thin-wall outer cyliner makes the NB stroke bush light weight an compact. ubrication One lubrication hole is provie on each oil groove of the outer cyliner, making it easy to lubricate the SR stroke bush. rotation ball elements retainer stopper ring AOWABE SPEE FOR COMBINE ROTATION AN STROKE MOTION The allowable spee for combine rotation an stroke motion is obtaine from the following equation: The value of N is given as follows epening on the lubrication metho. RATE OA AN RATE IFE The relationship between the rate loa an life of the stroke bush is expresse as follows: = ( fh ft fc C fw P ) : rate life fh: harness coefficient ft: temperature coefficient fc: contact coefficient fw: applie loa coefficient C: basic ynamic loa rating (N) P: applie loa (N) Refer to page Eng- for the coefficients. FIT The fits generally use between the shaft an the housing are liste in Table E-. The inner contact iameters of the SR stroke bush are liste in the imension tables. The shaft iameter shoul be selecte to achieve the esire amount of raial clearance (see Table E-). Please pay attention that high-spee linear motion can cause the retainer to slip ue to inertial force. In selecting a shaft, please take note of: Harness: HRC or more (refer to harness coefficient on page Eng-) recoene Surface Roughness: less than Ra.4 recoene Table E- normal operating conition shaft housing k,m H,H7 N m n+ S n for oil lubrication N=, for grease lubrication N=, note n, S n, For combine rotation an stroke motion h= (m n) +( S n) /m For stroke motion h= S n/(π m) h: life time (hr) S: stroke length () n: revolutions per min. (rpm) n: number of cycles per minute (cpm) m: ball pitch iameter (). r vertical use or highly accurate case shaft housing n,p J,J7 Table E- Raial Clearance Negative imit limit () 4 STROKE BUSH TYPE Table E- Type SR TYPE Stanar Type SR-B TYPE ouble Retainer Type P.E- P.E- E- E-
STROKE BUSH MOUNTING Examples of mounting methos of Stroke Bush are shown in Figure E-. To avoi eformation, o not fix outer cyliner by using set screw. Figure E- Mounting Metho using retaining rings using holing plates using set screws USE AN HANING PRECAUTIONS Maximum Stroke The maximum stroke in the imension table is the stroke limit. Retainer Slippage The retainer can slip uner high-spee motion, vertical application, unbalance-loaing, an vibrating conitions. It is suggeste that the stroke to be set as a % of the maximum stroke in the imension table. It is also recoene that the bush be cycle to perform the maximum stroke several times, so that the retainer returns to its central position. Accuracy The accuracies of the SR stroke bush are state in Figure E-4 Outer Cyliner Measurement Points the imension tables. Since the outer cyliner eforms ue to tension from the retaining ring, the imension of the outer cyliner is an average value at points P, where calculate using the following equation: W P P W stopper ring UBRICATION Appropriate lubrication is neee to ensure the accuracy of NB Stroke Bush an to maintain bearing life. Antirust oil is applie to NB Stroke Bush prior to shipment. The NB selecte anti-rust oil has a little to no effect on lubricants, however, please apply lubricant only after cleaning Stroke Bush with kerosene, etc. Grease ubricant Figure E- Oil hole Prior to usage, please apply grease, an re-lubricate perioically accoring to the operating conitions. (ithium soap-base grease is recoene.) Oil groove Relubrication can be one by irectly applying grease insie the ball bush or by using oil hole as Figure E- shows. A special low ust generation grease is optional for clean room application. Please refer to page Eng- 4. Oil hole Oil ubricant Prior to usage, please apply oil irectly to the shaft surface or by using oil hole as Figure E- shows. Turbine oil (ISO stanar VG-) is recoene. W=4+/ W: the istance from the en of the outer cyliner to measurement point P : the length of the outer cyliner Operating Temperature Range The operating temperature is ranging from - to. In case of operation at temperature outsie this range, please contact NB. ust Prevention ust an other contaminations affect the bush's lifetime an accuracy if ust or particle enter into insie of bush. Although seals work uner a normal environment, in a harsh environment, it is necessary to attach protective covers. STROKE BUSH E-4 E-
STROKE BUSH SR TYPE Stanar Type SR-UU TYPE Stanar Type with Seals structure example SR structure example SR UU SR type SR type inner contact iameter (r) inner contact iameter (r) seals on both sies SR SR SR SR SR SR SR SR SR SR 4 SR SR SR SR maximum stroke 9 4 4 9 number of rows r + + 9 +7 + + 7 + +4 4 + 7 +49 + +/+ 9 / f 4 7 7...4. 7..7 4. 9.......4.4 T.... t.....7.7.7......... r...... ynamic static mass C Co N N g 4 7,7,,,,99,4 4,,4,9 7,4,4 47 4 99,7,,4, 4,,9,, 4,7.9.. 4 7 99 7 9 7,4,,44 N.kgf SR UU SR UU SR UU SR UU SR UU SR UU SR UU SR UU SR 4UU SR UU SR UU SR UU SRUU maximum stroke 4 7 9 7 number of rows r + + 9 +7 + + 7 + +4 4 + 7 +49 + +/+ / 9 / f 4 7 7...4.. 7...... 9.9 77.4 77.4 77 77 T... t....7.7.7......... r..... ynamic static mass C Co N N g 4 7,7,,,,99,4 4,,4,9 7,4,4 4 99,7,,4, 4,,9,, 4,7.. 4 7 99 7 9 7,4,,44 N.kgf STROKE BUSH E- E-7
STROKE BUSH SR-B TYPE ouble Retainer Type SR-BUU TYPE ouble Retainer Type with Seals structure example SR B structure example SR B UU SR type SR type seals on both sies inner contact iameter (r) ouble retainer inner contact iameter (r) ouble retainer SR B SR B SR B SR B SR B SR B SR B SR B SR 4B SR B SR B SR B SRB maximum stroke 44 4 7 7 number of rows r + + 9 +7 + + 7 + +4 4 + 7 +49 + +/+ / 9 / f 4 7 7...4 7..7 4. 9.......4.4 T... t....7.7.7......... r..... ynamic static mass C Co N N g 49,,7,9,,7 4,,,7,97 9,7,7,7 49 9,,9,,7,7 7, 9,,, 4, 9,4.. 4 7 4 4,9,, N.kgf SR BUU SR BUU SR 4BUU SR BUU SR BUU SR BUU SRBUU maximum stroke 49 7 4 4 number of rows r +/+ +4 4 + 7 +49 + +/+ / 9 / f 7..4.. 9.9 77.4 77.4 77 77 T... t.... r ynamic static mass C Co N N g 4,,,7,97 9,7,7,7,7 7, 9,,, 4, 9,4 4 4,9,, N.kgf STROKE BUSH E- E-9
SRE SERIES TYPE Table E-4 Type The NB Slie Rotary Bush SRE Series provies rotary an linear motion functions. inear motion with unlimite stroke an rotary motion are merge into a single bush resulting in great space saving compare with a combination of any conventional bearings. There are three types; stanar, flange, an unit type with sizes ranging from to 4. SRE TYPE Stanar Type SREK TYPE Square Flange Type STRUCTURE AN AVANTAGES P.E- Unit P.E- NB Slie Rotary Bush features a special retainer fitte into cylinrical steel outer cyliner an is esigne to guie steel balls for smooth circulation in its retainer. The retainer is also esigne to rotate freely towars raial irection an offers smooth linear an rotary motions. Smooth Operation The inner surface of the outer cyliner allows smooth operation of linear an rotary motions while maintaining a uniform loa istribution. Complete Interchangeability NB Slie Rotary series is completely interchangeable with SM type Slie Bush, SMK type Flange Slie Bush an SMA(W) type, AK(W) type an SMP type. Figure E- Structure of Slie Rotary Bush SRE type outer cyliner rotation SMA-R TYPE AK-R TYPE Block Type P.E- ouble-wie Block Type SMA-RW TYPE AK-RW TYPE P.E- High oa Capacity The use of comparatively large iameter steel balls enhances the loa capacity. ball ellements Smooth Rotation The positioning of the steel balls in a cylinrical formation insie the retainer enables a smooth rotational motion regarless of the installation irection. linear motion retainer sie ring SMP-R TYPE P.E- P.E- P.E-4 E- E-
RATE OA AN RATE IFE FIT The rate life an loa rating are efine as follows. Rate ife When a group of slie rotary bearings of the same type are use uner the same conitions, the rate life is efine as the total number of rotations mae without causing flaking by 9% of the bearings. Basic ynamic oa Rating The basic ynamic loa rating is efine as the loa with a constant magnitue an irection at which a rate life of rotations can be achieve. Basic Static oa Rating The basic static loa rating is efine as the loa with a constant irection that woul result in a certain contact stress at the mi-point of the rolling element an tracking surface that are experiencing the maximum stress. Equation()gives the relation between the applie loa an the rate life of the slie rotary bush. = ( fh ft fc C fw P ) () : rate life (rotations) fh: harness coefficient ft: temperature coefficient fc: contact coefficient fw: applie loa coefficient C: basic ynamic loa rating (N) P: applie loa (N) Refer to page Eng- for the coefficients. Since the slie rotary bush is use in applications with combine linear an rotary motions, the life time is obtaine using Equations()an(). When linear an rotary motions are combine h= (m n) +( S n) () /m When only linear motion is involve h= () S n/(π m) h: life time (hr) S: stroke length () n: revolutions per minute (rpm) n: number of cycles per minute (cpm) m: ball pitch iameter ().r (r is the inner contact iameter of the SRE series) Shaft In orer to ensure high accuracy motion of Slie Rotary Bush SRE type, it is essential to select a high quality shaft. In selecting a shaft, please take note of: Outer iameter : g recoene Surface harness: HRC or higher For a shaft with surface harness l e s s t h a n H R C, m a ke a correction in life calculation by aing harness coefficient. Surface roughness: lower than Ra.4 or better MOUNTING Examples of mounting methos are shown in Figure E-. Please o not fix outer cyliner by using set screw to avoi eformation. Figure E- Mounting Metho Housing Inner iameter : H7 recoene using retaining rings using holing plates using set screws Calculation Example The life of SRE type NB slie rotary bush is calculate base on the following conitions. Conitions Motion: inear an rotational combine oa: P=N Stroke: S= Revolutions per minute: n=rpm Number of cycles per minute: n=cpm Shaft surface harness: greater than HRC Operating temperature: room temperature Other: single shaft with single bush Calculation Basic ynamic loa rating: C=47 N Base on the above conitions, the life is calculate using the following coefficient values. Harness coefficient fh=, Temperature coefficient ft=, Contact coefficient fc= Applie loa coefficient, fw= Rate life = ( fh ft fc C fw P ) = ( =,97 (rotations) 47 ) ife (in hours) h= (m n) +( S n) /m,97 = (. ) +( ) /(. ) =,9(h) E- E-
APPICATION EXAMPES USE AN HANING PRECAUTIONS Application Example Vertical Shaft Robot Arm Rotary Ball Spline SPR type Slie Rotary Flange Bush SREK type ubrication ubrication is neee () to prevent heat fusing by reucing friction between the rolling elements an the tracking surface, () to reuce wear of the structural elements, an () to prevent rusting. ubrication affects both the performance an life of the bush. A lubrication metho an a lubrication agent appropriate to the operating conitions shoul be selecte. For oil lubrication, turbine oil (ISO stanar VG-) is recoene. For grease lubrication, lithium soap base grease No. is recoene. The replenishment interval epens on the operating conitions. ust Prevention ust an other contaminants affect the bush's lifetime an accuracy. Appropriate prevention methos are thus important. Operating Temperature Range The operating temperature is ranging from - to. In case of operation at a temperature outsie this range, please contact NB. Retainer Material The stanar material of SRE Retainer is stainless steel. When requiring other material, please contact NB. FET SEA Application Example Multiple Gearing Iler Slie Rotary Bush SRE type Application Example 4 Turntable A felt seal FM strengthens lubrication characteristics an extens relubrication perio of the slie rotary bush. Figure E-7 Felt Seal elt B steel Installation The felt seal oes not work as a retaining ring. Figure E- shows how to install the felt seal. Table E-4 Felt Seal imensions () applicable B slie rotary bush FM FM FM FM FM FM FM FM FM FM 4 4 9 4 4 4 SRE SRE SRE SRE SRE SRE SRE SRE SRE SRE 4 Figure E- Example of Installation Application Example Tool Changer Slie Rotary Unit SMP-R type Slie Rotary Unit SMA-R type E-4 E-
SRE TYPE Stanar type structure example SRE SRE type inner contact iameter (r) r SRE 9 +4 SRE 4 SRE 9 9 SRE +. SRE SRE 7 SRE 4 + SRE 4 9 7 SRE 4. SRE4 4 +/ / 9 If the inner contact iameter excees 4, please contact NB. 7... 4 44.. B.. W.......... 4. 7. 4 7 ynamic C N 7 7 7 74 47,,9 static Co N 7 4 7,,, 4, allowable revolutions per minute rpm mass g 9 4 97 9 7 77 SRE SRE SRE SRE SRE SRE SRE SRE SRE SRE4 N.kgf E- E-7
SREK TYPE Square Flange type structure example SREK SREK type inner contact iameter (r) SREK SREK SREK SREK SREK SREK SREK SREK SREK r +4 + + 7 9 4 9 ±. f 9 4 9 4 4 4 7 4 4 4 9 4 74 K 4 7 4 flange t P.C.. 4 9 4 X Y Z.... 4. 7. 4. 4. 7. 4. 4. 7. 4. 4. 7. 4.. 9.. 9... perpenicularity static Co N ynamic C N 7 7 7 74 47, 7 4 7,,, allowable revolutions per minute rpm mass g 7 7 4 SREK SREK SREK SREK SREK SREK SREK SREK SREK N.kgf E- E-9
SMA-R TYPE -Block typepart number structure example SMA R SMA-RW TYPE -ouble-wie Block typepart number structure example SMA R W SMA-R type SMA-R type ouble type inner contact iameter inner contact iameter SMA R SMA R SMAR SMAR SMAR SMAR SMAR SMAR SMAR SMA4R inner contact iameter outer imensions h E W F G T 9 +4 7 4 4 4 4 + 44 9 4. 9 44.. 9 7 4 4 + 7 7 4 7 9 7 7 9. 49 4 +/ 4 9 7 B 4. 4 4 mounting imensions allowable ynamic static revolutions mass C K S f S C Co per minute N N rpm g M4.4 7 7 M4.4 7 4 M 4. 7 7 9.7 M 4. 74 4. M 4. 4 7 M 4. 4 7 M. 47, M 7, M 7,, 4 M.7,9 4,,79 N.kgf SMA RW SMA RW SMARW SMARW SMARW SMARW SMARW SMARW SMARW SMA4RW allowable inner contact iameter outer imensions mounting imensions ynamic static revolutions mass h E W F G T N B C K S f S C Co per minute N N rpm g 9 4 7 M4.4 +4 7 4 7 4 4 M4.4 4 7 4 M 4. 4 744 4 7 4...7 M 4. 444, + 44 7 4... M 4.,7 4 9.. 9 7 M 4. 7,7 4 7 4 9 4 7 4 7 7 M.,, + 7 4 4 4 M 7,4,7, 7 9 7 4 9. 49 M 7,9,, 4 +/ 4 7 7 4 M.7,,4,49 N.kgf E- E-
AK-R TYPE -Compact Block typepart number structure example AK R AK-RW TYPE -ouble-wie Compact Block typepart number structure example AK R W AK-R type AK-R type ouble type inner contact iameter inner contact iameter AK R AK R AKR AKR AKR AKR AKR AKR AKR inner contact iameter outer imensions mounting imensions h E W F S f t S S 4 7 M4 9 M4. +4 M. M4. 9 9 7 M 9. M 4. 4 4 4 7 M 9. M 4. + 4 4 M 7 M. 7 47 49 M 7 M. 4 4 M M 7 + 7 9 4 M 7 9 M.9 7 4 9 74 7 44 M 7. 9 M.9 9 9 4 4 allowable ynamic static revolutions mass H C Co per minute N N rpm g 7 7 7 4 7 7 74 7 7 7 4 94 47,,,, 9 N.kgf AK RW AK RW AKRW AKRW AKRW AKRW AKRW AKRW AKRW inner contact iameter outer imensions mounting imensions h E W F S f t S S 4 4 M4 M4. +4 M. 4 M4. 9 M 9. M 4. 4 7 4 M 9. M 4. + 74 4 4 M 7 M. 7 4 49 M 7 M. 4 94 4 M 7 M 7 + 7 M 7 9 M.9 7 4 9 7 9 M 7. 9 M.9 9 9 4 4 allowable ynamic static revolutions mass H C Co per minute N N rpm g 4 744 7 7 4 9 7 444,,7 7,7,, 9,4,7,9,,99, N.kgf E- E-
SMP-R TYPE -Pillow Block typepart number structure example SMP R SMP-R type inner contact iameter SMPR SMPR SMPR SMPR SMPR SMP4R inner contact iameter + 4 + 7 +/ h 9 4 4 outer imensions E W F 4 7. 7. 4 7 9 7 4. 4 4 4 G M 4 4 9 9 P 7 4 49 B 4 7 mounting imensions C S 9 4 4 4 7(M) 7(M) (M) (M) (M) (M) ajustment screw size S M M M M M M ynamic static C Co N N 47,,9,,, 4, allowable revolutions per minute rpm mass g 9 9 97,4, SMPR SMPR SMPR SMPR SMPR SMP4R N.kgf E-4 E-
RK TYPE NB's RK type slie rotary bush is a highly accurate an high loa capacity bearing proviing smooth continuous linear an rotational motions. Its structure imposes no constraints on linear an rotational motions. It is much more compact than a stanar slie bush with separate rotational bearing. RK TYPE structure example RK G UU - OH STRUCTURE AN AVANTAGES The RK type slie rotary bush uses a retainer similar to that use in the SR type stroke bush. This retainer gives a smooth motion in a high rotational application. SM type slie bush is incorporate, proviing the stable an smooth linear motion. Relatively large ball elements are use for high loa capacity. Figure E-9 Structure of RK Slie Rotary Bush linear motion outer cyliner FIT rotation retainer slie bush Shaft In orer to ensure high accuracy motion of Slie Rotary Bush RK type, it is essential to select a high quality shaft. In selecting a shaft, please take note of: Outer iameter : h recoene Surface harness: HRC or higher For a shaft with surface harness l e s s t h a n H R C, m a ke a correction in life calculation by aing harness coefficient. Surface roughness: lower than Ra.4 or better.a smooth unlimite linear an rotational motion is obtaine..there is no nee to machine separate housing..high accuracy is ensure for extene perio of usage. 4.Its high compatibility eliminates replacement problems..h i g h r i g i i t y e n a b l e s i t t o withstan an unbalance loa an large loa. For best performance, please select of h for the shaft. Housing Inner iameter is not requeste. Please insert into an installation bore which is slightly larger than the outer cyliner. RK type inner contact iameter (r) *Oil hole is for rotary-portion lubrication. RKGUU RKGUU RKGUU RKGUU RKGUU K r 9 4 mounting hole x 4 7 74 () oil hole blank: without oil hole OH: with oil hole * seals on both sies f P.C.. A f 4 9. ±. 74. 9 resin retainer K 4 4 7 t flange t P.C.. 4 7 7 (oil hole) X Y Z. 9.. 9..... 9 4. A r allowable ynamic static revolutions mass C Co per minute N N rpm g 74 774,,7 4 4 9,7 4,7,74 4 99 N.kgf ife Calculation = ( fh ft fc C fw P ) : rate life (km) fh: harness coefficient ft: temperature coefficient fc: contact coefficient fw: applie loa coefficient C: basic ynamic loa rating (N) P: applie loa (N) Refer to page Eng- for the coefficients. E- E-7