Speed Reducers for Precision Motion Control Reducer Catalog

Transcription

1 Speed Reducers for Precision Motion Control Reducer Catalog CSF-mini

2 Excellent Technology for Evolving Industries Harmonic Drive actuators utilize high-precision, zero-backlash Harmonic Drive precision gears and play critical roles in robotics, semiconductor manufacturing equipment, factory automation equipment, medical diagnostics and surgical robotics. Additionally, our products are frequently used in mission-critical spaceflight applications which capture the human spirit. With over years of experience, our expert engineering and production teams continually develop enabling technologies for the evolving motion control market. We are proud of our outstanding engineering capabilities and successful history of providing customer specific solutions to meet their application requirements. Harmonic Drive LLC continues to develop enabling technologies for the evolving motion control market, which drives the pace of global innovation. C. Walton Musser Patented Strain Wave Gearing in 19

3 Operating Principle of Gears A simple three-element construction combined with the unique operating principle puts extremely high reduction ratio capabilities into a very compact and lightweight package. The high-performance attributes of this gearing technology including, zero-backlash, high-torque-to-weight ratio, compact size, and excellent positional accuracy, are a direct result of the unique operating principles. Wave Generator The Wave Generator is a thin, raced-ball bearing fitted onto an elliptical hub. This serves as a high-efficiency torque converter and is generally mounted onto the input or motor shaft. Flexspline The Flexspline is a non-rigid, thin cylindrical cup with external teeth on the open end of the cup. The Flexspline fits over the Wave Generator and takes on its elliptical shape. The Flexspline is generally used as the output of the gear. Circular Spline The Circular Spline is a rigid ring with internal teeth. It engages the teeth of the Flexspline across the major axis of the Wave Generator ellipse. The Circular Spline has two more teeth than the Flexspline and is generally mounted onto a housing. Circular Spline 9 1 Wave Generator Flexspline The Flexspline is slightly smaller in diameter than the Circular Spline and usually has two fewer teeth than the Circular Spline. The elliptical shape of the Wave Generator causes the teeth of the Flexspline to engage the Circular Spline at two opposite regions across the major axis of the ellipse. As the Wave Generator rotates the teeth of the Flexspline engage with the Circular Spline at the major axis. For every 1 degree clockwise movement of the Wave Generator, the Flexspline rotates counterclockwise by one tooth in relation to the Circular Spline. Each complete clockwise rotation of the Wave Generator results in the Flexspline moving counterclockwise by two teeth from its original position, relative to the Circular Spline. Normally, this motion is taken out as output. Development of HarmonicDrive Speed Reducers Harmonic Drive gears have been evolving since the strain wave gear was first patented in 19. Our innovative development and engineering teams have led us to significant advances in our gear technology. In 19, Harmonic Drive successfully designed and manufactured a new tooth profile, the "S" tooth. Since implementing the "S" tooth profile, improvement in life, strength and torsional stiffness have been realized. In the 199s, we focused engineering efforts on designing gears featuring space savings, higher speed, higher load capacity and higher reliability. Then in the s, significant reduction in size and thickness were achieved, all while maintaining high precision specifications.

4 CSG-UP CSF-mini Series Gear Unit CSF-mini Features Ordering code Technical data Technical data of input shaft type Rating table Positional accuracy Hysteresis Backlash Starting torque Backdriving torque Ratcheting torque Buckling torque Checking output bearing Lubrication Shaft output: outline dimensions 1U Rating table Flange output: outline dimensions 1U-F Torsional stiffness Output bearing and housing tolerances Efficiency No-load running torque Allowable load on the input shaftt Installation and transmission torque Technical data Motor mounting type Shaft output: outline dimensions 1U-CC Rating table Flange output: outline dimensions 1U-CC-F Rating table Flange output: outline dimensions XH-F Rating table Shaft output: outline dimensions XH-J Rating table Wave Generator Hole Diameter Torsional stiffness Output bearing and housing tolerances Efficiency No-load running torque Example of installation Assembly tolerances Installation and transmission torque Sealing mechanism

5 Gear Unit CSF mini Features CSF-mini series CSF mini gearheads provide excellent positioning accuracy in a super-compact package. Compact -point contact bearing on the output side to support external loads. Available in four sizes and four ratios, the CSF mini gearheads feature shaft or flange outputs. Features Zero backlash Compact and lightweight High-torque capacity High-torsional stiffness Excellent positional accuracy Coaxial input and output Ordering Code The HarmonicDrive CSF-mini series consists of a wide variety of products including four sizes and six models. CSF XH - F - SP Table 17-1 Series Ratio*1 Model Special specification CSF U= Input shaft, shaft output 1U-F= Input shaft, flange output 1U-CC= Square flange type, shaft output 1U-CC-F= Square flange type, flange output XH-J= Square flange type, shaft output XH-F= Square flange type, flange output SP= Special specification code Blank = Standard product *1 The reduction ratio value is based on the following configuration: Input: wave generator, fixed: circular spline, output: flexspline Technical Data Rating table Table 17- Ratio Rated Torque at input speed rpm Limit for Repeated Peak Torque Limit for Average Torque Limit for Momentary Peak Torque Maximum Input Speed Limit for Average Input Speed Moment of Inertia ( 1 /GD ) Nm Nm Nm Nm rpm rpm kgcm * The upper value of moment of inertia is for 1U, whereas, the lower value of it is for XH. 17

6 Structure Input shaft version This unit can be driven by a belt, coupling or a gear mounted on the input shaft. Available with shaft output or flange output. Shaft output: 1U Flange output: 1U-F Gear Unit CSF mini Fig Four-point contact ball bearing Output shaft (low-speed shaft) Circular spline Input shaft (high-speed shaft) Output flange Shaft output Flexspline Wave generator Motor mounting type This gearhead is designed to be mounted to a motor, with the use of an adapter plate. 1U shaft output: 1U-CC 1U flange output: 1U-CC-F Square flange version: XH-J Four-point contact ball bearing Output shaft (low-speed shaft) Circular spline Flange output: XH-F Output Flexspline Wave generator (input part) * The rotational direction of the output shaft is opposite to that of the input shaft (wave generator) when the housing is fixed. 171

7 Gear Unit CSF mini Positional accuracy Ratio Specification 1 - rad arc min 1 - rad or more arc min See "Engineering data" for a description of terms Table 17-1 Hysteresis See "Engineering data" for a description of terms. Table 17- Ratio or more 1 - rad arc min 1 - rad arc min 1 - rad arc min Max. backlash See "Engineering data" for a description of terms. Table 17- Ratio rad arc sec 1 - rad arc sec 1 - rad arc sec 1 - rad arc sec Starting torque Ratio 1 See "Engineering data" for a description of terms. Please use as reference values; the values vary based on use conditions Table 17- Unit: Ncm Backdriving torque Ratio See "Engineering data" for a description of terms. Please use as reference values; the values vary based on use conditions Table 17- Unit: Nm Ratcheting torque Ratio 1 Buckling torque All ratios See "Engineering data" for a description of terms See "Engineering data" for a description of terms Table 17- Unit: Nm Table 17-7 Unit: Nm 17

8 Checking output bearing A precision -point contact ball bearing is built into the CSF-mini series to directly support the external load. Check the maximum moment load, life of the -point contact ball bearing and static safety coefficient to fully maximize the performance of the CSF-mini series. See page to of "Engineering data" for each calculation formula. Gear Unit CSF mini Checking procedure (1) Checking the maximum moment load (Mmax) Calculate the maximum moment load (Mmax). () Checking the life Calculate the radial load (Frav) and the average axial load (Faav). () Checking the static safety coefficient Calculate the static equivalent radial load coefficient (Po). Maximum moment load (Mmax) allowable moment (Mc) Calculate the radial load coefficient (x) and the axial load coefficient (y). Check the static safety coefficient. (fs) Calculate the lifetime Output bearing specifications Specifications Table 17-1 Pitch circle dp Offset R Basic dynamic rated load Basic rated load Basic static rated load Allowable moment load Moment rigidity Allowable radial load * Allowable axial load 11 1 mm mm N N Nm Nm/rad N N * Allowable radial load is the value on the center of output shaft side of both shaft type (1U) and that of gearhead shaft output type (XH-J). * The value of the moment stiffness is the average value. Lubrication The standard CSF-mini gearheads are shipped already lubricated with grease. The table shows the grease that is used in the gear reducer and in the output bearing. Lubricated area Lubricant Manufacturer Base oil Base Viscosity cst ( o C) Gear Harmonic Grease SK- Harmonic Drive Systems Refined oil Output bearing Multemp HL-D Kyodo Yushi Composite hydrocarbon oil 9 Thickening agent Lithium soap Lithium soap Table 17- Drop point 19 o C 1 o C Appearance Green White 17

9 Gear Unit CSF-1U Outline Dimensions Shaft output: outline dimension of 1U You can download the CAD files from our website: harmonicdrive.net Fig (Note) (Note) V-W equally spaced Max. dia. of motor X-Y equally spaced a Dimensions Center of output shaft * Refer to the confirmation drawing for detailed dimensions (Note) There is no positional relationship between the flat on the output shaft and the V-W tapped holes. Table 17-1 Unit: mm Symbol φa B C D E F G H I J K L φm h7 φn φo h φp φq h R S φt φu V W X Y Z a Mass (g) ±.. 9. M M ± ±. 1. M M ± ±. 1.. M M ± ±. 1. M M 1 ±

10 Outline Dimensions Flange output: outline dimension of 1U-F You can download the CAD files from our website: harmonicdrive.net Gear Unit CSF-1U V-W equally spaced Max. dia. of motor X-Y equally spaced Dimensions * Refer to the confirmation drawing for detailed dimensions Table 17-1 Unit: mm Symbol φa B C D E F G H I J K φm h7 φn φo H7 φp ΦQ h R φt φu V W X Y Z a Mass (g) ±. 9. M M.± ±. 1. M M ± ±.. M M ± ±.. M M 1 ±

11 Gear Unit CSF-1U Torsional stiffness Symbol Ratio Ratio Ratio or more T1 T K1 K K θ1 θ K1 K K θ1 θ K1 K K θ1 θ Nm kgfm Nm kgfm 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 - rad arc min 1 - rad arc min 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 - rad arc min 1 - rad arc min 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 - rad arc min 1 - rad arc min 1U See "Engineering data" for a description of terms. 1U-F U U-F * The values in this table are reference values. The minimum value is approximately % of the displayed value. 1U U-F U Table U-F Mechanical precision The CSF-mini series gearheads have -point contact bearings on the output side to support external loads. The mechanical precision of the output shaft and output flange is shown below. The output shaft of the input shaft version φb A φb A a a Fig Recommended housing tolerances Symbol Precision item a b c d e 1U 1U-F Concentricity Perpendicularity Runout Runout on the edge of the output flange Runout on the inner diameter of the output flange Parallelism 1U U-F. 1U. * T.I.R.: This indicates the total reading of the dial gauge when the measuring part is rotated once..... A 1U-F. d e c B B A 1U U-F. A d e c B A 1U. B Table 17- * T.I.R. Unit: mm.... 1U-F. 17

12 Efficiency The efficiency varies depending on the following conditions. Reduction ratio Input rotational speed Load torque Temperature Lubrication (type and quantity) Measurement condition Load torque Rated torque in rating table (see Page 17) Lubricant Grease lubrication Name Quality Gear Unit CSF-1U Harmonic Grease SK- Recommended quantity Table Efficiency compensation coefficient When the load torque is lower than the rated torque, the efficiency value decreases. Calculate compensation coefficient Ke from Graph Example of calculation Efficiency η (%) under the following condition is obtained from the example of CSF--1-1U. Input rotational speed: 1 rpm Load torque:. Nm Lubrication method: Grease lubrication Lubricant temperature: o C Since the rated torque of size with a reduction ratio of 1 is. Nm (Ratings: Page 17), the torque ratio α is.. (α=./..) The efficiency compensation coefficient is Ke=.99 from Graph Efficiency η at load torque. Nm: η=ke ηr=.99 x 77%=7% * When the load torque is higher than the rated torque, efficiency compensation value Ke is 1. Efficiency compensation coefficient Torque ratio Graph Compensation coefficient Ke η R η =Ke ηr = Efficiency at the rated torque Load torque Torque ratio α = Rated torque 177

13 Gear Unit CSF-1U Efficiency at rated torque Ratio Ratio Ratio Graph Graph Graph Ambient Temperature ( o C) Ambient Temperature ( o C) Ambient Temperature ( o C) Efficiency (%) Ratio 1 Graph Efficiency (%) 11 Ratio 1 Graph Efficiency (%) 1 Ratio Efficiency (%) Graph 17-1 Efficiency (%) Efficiency (%) Efficiency (%) Ratio 1 Graph Ratio 1 Graph Ratio 1 1 Graph Ratio 1 1 Graph Ambient Temperature ( o C) Ambient Temperature ( o C) Ambient Temperature ( o C) Input rotational speed Ambient Temperature ( o C) Ambient Temperature ( o C) Ambient Temperature ( o C) Ambient Temperature ( o C) Ambient Temperature ( o C) Ambient Temperature ( o C) Efficiency (%) Ratio Graph rpm 1rpm rpm rpm Efficiency (%) Efficiency (%) Efficiency (%) Efficiency (%) Ratio and 1 Graph

14 No-load running torque No-load running torque is the torque which is required to rotate the input side (high speed side), when there is no load on the output side (low speed side). Gear Unit CSF-1U Measurement Condition Table Ratio Lubrication type Grease lubrication Name Harmonic Grease SK- Torque value is measured after hours at rpm input. Compensation Value in Each Ratio No-load running torque of the gear varies with ratio. Graphs to 179- show the values for a reduction ratio of 1. For other gear ratios, add the compensation values in the right-hand table (Table 179-). No-load running torque for a reduction ratio of 1 Input speed: rpm Table 179- No-Load Torque Running Torque Compensation Value Unit: Ncm Ratio Input speed: 1rpm Graph Graph 179- No-load running torque (Ncm) No-load running torque (Ncm) Ambient Temperature ( o C) Ambient Temperature ( o C) No-load running torque (Ncm) Input speed: rpm Graph Ambient Temperature ( o C) Ambient Temperature ( o C) No-load running torque (Ncm) Input speed: rpm Graph *The values in this graph are average values (X). 179

15 Gear Unit CSF-1U Performance data for the input bearing Performance data for the input bearing The input shaft type is supported by two deep groove single row ball bearings. Please check the loading on the input shaft to make sure that it is acceptable. Figure 1-1, Table -1, Graph 1-1 show the points of application of forces, which determine the maximum allowable radial and axial loads as indicated. The values in Graph 1-1 are valid for an average input speed of rpm and a mean bearing life of L1=7h. Example: When an -N axial load (Fa) is applied to the size 1 input shaft, the value of the maximum allowable radial load (Fr) is N. Specification for Input Bearing Bearing A Basic dynamic Model rated load Cr(N) 11 1 SSLF-DD MR1 9 9ZZ Basic static rated load Cor(N) Model L-WO MR ZZ Bearing B Basic dynamic rated load Cr(N) Basic static rated load Cor(N) 17 Distance between bearings a a(mm) Overhang length of the input shaft b b(mm) Table 1-1 Maximum radial load Fr(N) 1 Supporting point of the roller bearing Fig. 1-1 Relation between the radial load and the axial load Graph 1-1 Bearing B Bearing A Fr Fa+ Radial load Fr (N) 1 : : 1 : 11 Fa: Axial load (N) Fr: Radial load (N) a b : 1 Axial load Fa (N) Installation and transmission torque Installation on the equipment Check the mating surface for flatness and any burrs prior to mounting the CSF-mini product. Use the proper screws and tightening torque as specified in Table 1-. Tightening torque of the bolt* of the mounting flange (A in Figure 11-1) Item 11 1 Number of bolts Table 1- Bolt size M M M M Pitch circle mm Clamp torque Screw Transmission torque Nm mm Nm. * Recommended bolt: JIS B 117 hexagonal bolt,strength: JIS B or higher

16 Mounting flange Fig Gear Unit CSF-1U Part A Installation of the load on the output part Install the load on the output part taking the specifications of the output bearing (see Page 17) into consideration. Tightening torque of the bolt* of the mounting flange (B in Figure 11-) 11 1 Item Number of bolts Table 11-1 Bolt size M M M M Pitch circle Clamp torque Transmission torque mm Nm Nm As measures have been taken against oil leakage of the output flange, no sealing agent needs to be applied. * Recommended bolt: JIS B 117 hexagonal bolt, strength: JIS B or higher... Mounting flange (1U-F) Fig. 11- Part B Do not allow the output shaft to receive a shock when you install a pulley and pinion. It can deteriorate the precision of the reducer and cause failure. 11

17 CSF-XH/CSF-1U-CC Outline Dimensions Shaft output: outline dimensions 1U-CC You can download the CAD files from our website: harmonicdrive.net Fig. 1-1 a-b equally spaced φ φ φ φ Max. dia. of motor φ With locking screw φ φ φ e-f equally spaced φ Wave generator installation dimension for size c-d equally spaced Center of output shaft Wave generator Reverse for motor with long output shaft +.. * Please refer to the confirmation drawing for detailed dimensions. The dimension tolerances that are not specified vary depending on the manufacturing method. Please check the confirmation drawing or contact us for dimension tolerances not shown on the drawing.* See Fig. - on Page for the shapes of the wave generator. Dimensions Symbol φa B* C D E* F G H I J K L M N O φp h7 φq φr h φs h φt H7 U φv φw X φy a b c d e f g* h* Mass (g) M ± M M M 7 ー 7 *The B, E, g and h dimensions indicated by an asterisk are the mounting positions in the shaft direction and allowance of the three parts (wave generator, flexspline, circular spline). Strictly observe these dimensions as they affect the performance and strength M ±. 1. M M M M ±.. 1. M M M M ±.. 1 M M 1 M Wave generator is removed when the product is delivered Table 1-1 Unit : mm 1

18 Flange output: outline dimensions 1U-CC-F You can download the CAD files from our website: harmonicdrive.net CSF-XH/CSF-1U-CC Fig. 1-1 a-b equally spaced φ φ φ φ Max. dia. of motor H7 φ With locking screw φ φ φ e-f equally spaced φ Wave generator installation dimension for size c-d equally spaced Wave generator Reverse for motor with long output shaft +.. * Please refer to the confirmation drawing for detailed dimensions. The dimension tolerances that are not specified vary depending on the manufacturing method. Please check the confirmation drawing or contact us for dimension tolerances not shown on the drawing.* See Fig. - on Page for the shapes of the wave generator. Dimensions Symbol φa B* C D E* F G H I J K L M N φp h7 φq φr H7 φs h φt H7 U φv φw φy a b c d e f g* h* Mass (g) M ±. 9.. M M M 17 ー *The B, E, g and h dimensions indicated by an asterisk are the mounting positions in the shaft direction and allowance of the three parts (wave generator, flexspline, circular spline). Strictly observe these dimensions as they affect the performance and strength M ±. 1. M M M M ±.. M M M M ±.. M M 1 M Wave generator is removed when the product is delivered Table 1-1 Unit : mm 1

19 CSF-XH/CSF-1U-CC Flange output: outline dimensions XH-F You can download the CAD files from our website: harmonicdrive.net Fig. 1-1 X-Y equally spaced U I B* C E H F D* G g (O-ring) K-L e* f* Wave generator installation dimension for size e* J a-b equally spaced φw φv φp h7 φq Max. dia. of motor φr H7 c-d equally spaced M O N J φt H7 φs h φa Wave generator Reverse for motor with long output shaft N. +. * Please refer to the confirmation drawing for detailed dimensions. The dimension tolerances that are not specified vary depending on the manufacturing method. Please check the confirmation drawing or contact us for dimension tolerances not shown on the drawing.* See Fig. - on Page for the shapes of the wave generator. Dimensions Symbol φa B* C D* E F G H I J K L M N O φp h7 φq φr H7 φs h φt H7 U φv φw X Y a b c φd e* f* g (accessory) Mass (g) M ±. 9. M M. 17 ー *The B, D, e and f dimensions indicated by an asterisk are the mounting positions in the shaft direction and allowance of the three parts (wave generator, flexspline, circular spline). Strictly observe these dimensions as they affect the performance and strength M ± MX M M ±.. M M M ±.. M M Wave generator is removed when the product is delivered. Table 1-1 Unit : mm 1

20 Shaft output: outline dimensions XH-J You can download the CAD files from our website: harmonicdrive.net (note) a-b equally spaced (note) z C N I B* D F G J E* H i (O-ring) L-M g* CSF-XH/CSF-1U-CC h* Wave generator installation dimension for size g* K Fig. 1-1 c-d equally spaced W φy φx φr h7 φs Max. dia. of motor φt h e-f equally spaced P Q Center of output shaft O K φv H7 φu h φa Wave generator Reverse for motor with long output shaft (Note) There is no positional relationship between the flat on the output shaft and the a-b tapped holes. O. +. * Please refer to the confirmation drawing for detailed dimensions. The dimension tolerances that are not specified vary depending on the manufacturing method. Please check the confirmation drawing or contact us for dimension tolerances not shown on the drawing.* See Fig. - on Page for the shapes of the wave generator. Dimensions Symbol φa B* C D E* F G H I J K L M N O P Q φr h7 φs φt h φu h φv H7 W φx φy Z a b c d e φf g* h* i (accessory) Mass (g) M ±. 9.. M M. 7 ー *The B, E, g and h dimensions indicated by an asterisk are the mounting positions in the shaft direction and allowance of the three parts (wave generator, flexspline, circular spline). Strictly observe these dimensions as they affect the performance and strength M ± M M M ±.. 1. M M M ±.. 1 M M Table 1-1 Unit : mm Wave generator is removed when the product is delivered. 1

21 CSF-XH/CSF-1U-CC Hole diameter of the wave generator The standard hole dimension of the Wave Generator for each size is shown. The dimension can be changed within a range up to the maximum hole dimension shown in the following table to match the shaft diameter of the mounting motor. Table 1-1 Unit: mm Symbol XH-F:φT H7 XH-J:φV H7 1U-CC-F:φT H7 1U-CC:φT H7 T1 T K1 K K θ1 θ K1 K K θ1 θ K1 K K θ1 θ Nm kgfm Nm kgfm 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 - rad arc min 1 - rad arc min 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 - rad arc min 1 - rad arc min 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 Nm/rad kgfm/arc min 1 - rad arc min 1 - rad arc min 11 1 Note 1: The standard Wave Generator has an Oldham coupling to compensate for any misalignment. The parenthesized value indicates the value for an input without an Oldham coupling (known as a solid wave generator). The size is standard with a solid wave generator. Note : The size of the set screw may be changed due to the hole diameter. Note : A keyway may be incorporated, depending on the hole diameter. Note : Special specifications apply to all changes of the hole diameter size. Contact our office for details of the sizes. Torsional stiffness Symbol Ratio Ratio Ratio or more 1. to 11 1 XH-J/1U-CC XH-F/1U-CC-F XH-J/1U-CC XH-F/1U-CC-F XH-J/1U-CC XH-F/1U-CC-F XH-J/1U-CC XH-F/1U-CC-F to ( to ) to 7 ( to ) to ( to 1) See "Engineering data" for a description of terms * The values in this table are reference values. The minimum value is approximately % of the displayed value Table

22 Output bearing and housing tolerances The CSF-mini series gearheads have -point contact bearings on the output side to support external loads. The mechanical precision of the output shaft and output flange is shown below. CSF-XH/CSF-1U-CC Shaft output Fig Flange output Fig. 17- XH-J 1U-CC XH-F 1U-CC-F φb a A φb a A φb a A φb a A A d e c B A B A d e c B B A d e c A B A B A d e c B A B Symbol Precision item Table 17-1 * T.I.R. Unit: mm 11 1 XH-J/1U-CC XH-F/1U-CC-F XH-J/1U-CC XH-F/1U-CC-F XH-J/1U-CC XH-F/1U-CC-F XH-J/1U-CC XH-F/1U-CC-F a b c Runout of the output shaft Runout of the pilot hole in the output flange Concentricity of the mounting pilot Perpendicularity of the mounting face d Runout on the output flange face.... e Parallelism of the mounting face and the output flange face.1... * T.I.R.: This indicates the total reading of the dial gauge when the measuring part is rotated once. Efficiency The efficiency varies depending on the following conditions. Reduction ratio Input rotational speed Load torque Temperature Lubrication (Type and quantity) Efficiency compensation coefficient If the load torque is lower than the rated torque, the efficiency value lowers. Calculate compensaiton coefficient Ke from Graph 1-1 to calculate the efficiency using the following example. Calculation Example Efficiency η (%) under the following condition is calculated from the example of CSF--1-XH. Input rotational speed: 1 rpm Load torque:. Nm Lubrication method: Grease lubrication Lubricant temperature: o C Since the rated torque of size with a reduction ratio of 1 is. Nm (Ratings: Page 171), the torque ratio α is.. (α=./..) The efficiency compensation coefficient is Ke=.99 from Graph 1-1. Efficiency η at load torque. Nm: η=ke ηr=.99 x 77%=7% * Efficiency compensation coefficient Ke=1 holds when the load torque is greater than the rated torque. Measurement condition Load torque Rated torque in rating table (see Page 17) Lubricant Efficiency compensation coefficient Compensation coefficient Ke Grease lubrication Name Quantity Harmonic Grease SK- Recommended quantity η R η =Ke ηr = Efficiency at the rated torque Load torque Torque ratio α = Rated torque Torque ratio Table 17- Graph

23 CSF-XH/CSF-1U-CC Efficiency at rated torque Ratio Graph Graph Graph Ambient Temperature ( o C) Ambient Temperature ( o C) Ambient Temperature ( o C) Efficiency (%) Efficiency (%) Ratio Efficiency (%) Ratio Ratio Ratio 1 Graph Graph Graph Efficiency (%) Efficiency (%) Efficiency (%) Ratio 1 Ambient Temperature ( o C) Ambient Temperature ( o C) Ambient Temperature ( o C) 11 Ratio Efficiency (%) Efficiency (%) Ratio Ratio 1 Graph Graph Ambient Temperature ( o C) Ambient Temperature ( o C) Ambient Temperature ( o C) 1 Ratio Efficiency (%) Ratio Graph Graph Graph Ambient Temperature ( o C) Ambient Temperature ( o C) Ambient Temperature ( o C) Input rotational speed Graph 1-7 Efficiency (%) rpm 1rpm rpm rpm Efficiency (%) Efficiency (%) Ratio and 1 1

24 No-load running torque No-load running torque is the torque which is required to rotate the input side (high speed side), when there is no load on the output side (low speed side). CSF-XH/CSF-1U-CC Measurement condition Table 19-1 Ratio Lubricant Grease lubrication Name Harmonic Grease SK- Torque value is measured after hours at rpm input. Compensation Value in Each Ratio No-load running torque of the gear varies with ratio. The graphs indicate a value for ratio 1. For other gear ratios, add the compensation values from table on the right. No-load running torque for a reduction ratio of 1 Input speed: rpm Table 19- No-Load Torque Running Torque Compensation Value Unit: Ncm Ratio Input speed: 1rpm Graph Graph 19- No-load running torque (Ncm) No-load running torque (Ncm) Ambient Temperature ( o C) Ambient Temperature ( o C) No-load running torque (Ncm) Input speed: rpm Graph Ambient Temperature ( o C) Ambient Temperature ( o C) No-load running torque (Ncm) Input speed: rpm Graph *The values in this graph are average values (X). 19

25 CSF-XH/CSF-1U-CC Example of installation The following examples show a CSF-XH miniature gearhead mounted to a motor. Mounting flange Fig Fig. 19- This example shows the wave generator flipped to allow for full motor shaft engagement with Mounting flange access to the set screws. Motor matching table The table below provides a rough guide for matching a gearhead to a motor, based on the motor wattage. Note that the motor shaft diameter may not always match the diameter of the gearhead's standard input hub. The input hub can be supplied with a non-standard diameter, see Page 1 Table 19-1 Motor capacity W W 1W W W (Note) 11 1 The shaft diameter of some motors may not fit the hole diameter of the standard wave generator. In this case, the hole diameter should be changed (hole diameter size: see Page 1). Changes to the hole diameter should be performed using special specifications. 19

26 Recommended tolerances for assembly Maintain the recommended tolerences shown in Figure and Table for maximum performance of CSF mini gearheads. CSF-XH/CSF-1U-CC Recommended assembly tolerances Fig Recommended allowance of the case A φ c A Recommended allowance of the shaft h a A Case mating face b A Wave generator mounting face Recommended assembly tolerances Symbol Precision item a Perpendicularity of mounting flange b c Perpendicularity of the input hub Concentricity of the input shaft (.).1 (.).11.1 (.7).1 (.7) * The standard Wave Generator has an Oldham coupling to compensate for any misalignment. The parenthesized value indicates the value for an input without an Oldham coupling (known as a solid wave generator). The size is standard with a solid wave generator (.). (.1) Table Unit: mm H7 191

27 CSF-XH/CSF-1U-CC Installation and transmission torque Installation Check the mating surface for flatness and for burrs prior to mounting the CSF-mini product. Use the proper screws and the tightening torque as specified in Table 19-1 and 19-. Bolt tightening torque* of the mounting flange (A in Figure 19-1) /XH type Table Item Number of bolts Bolt size Pitch circle Clamp torque Screws Transmission torque mm Nm mm Nm M.. M M.. 1 M.. 1 * Recommended bolt: JIS B 117 hexagonal bolt, strength: JIS B or higher Bolt tightening torque* of the mounting flange (A and C part in Figure 19-) /1U-CC type Table Item Number of bolts Bolt size Pitch circle Clamp torque mm Nm Part A Part C Part A Part C Part A Part C Part A Part C M. M.. M. M.. M. M. M. M. Screws mm 1 Transmission torque Nm * Recommended bolt: JIS B 117 hexagonal bolt, strength: JIS B or higher 19

28 Installation of the load on the output part Install the load on the output part of the CSF-mini series taking the specifications of the output bearing (see Page 17) into consideration. CSF-XH/CSF-1U-CC Bolt tightening torque* of the mounting flange (B in Figure 19-1 and Figure 19-) (flange output type) 11 1 Item Table 19-1 Number of bolts Bolt size M M M M Pitch circle Clamp torque Transmission torque mm Nm Nm Output Flange is treated to prevent for grease leakage, re-sealing is not necessary. * Recommended bolt: JIS B 117 hexagonal bolt, strength: JIS B or higher.... Mounting flange (XH-F) Fig Mounting flange (1U-CC-F) Fig. 19- Part B Part A Part B Part A Part C Avoid impact to the output flange during assembly. It may result in damage to the gearhead. 19

29 CSF-XH/CSF-1U-CC Sealing Sealing is required to prevent grease leakage Mating flange Use the O-Ring supplied with the gearhead, as well as a seal adhesive, such as gasket eliminator. Make sure the O-Ring is seated properly. Screw hole area Area requiring sealing and recommended sealing methods Area requiring sealing Input side Mating flange Motor output shaft Apply LOCTITE to the screw threads. Recommended sealing method Use O-ring (supplied with the product) Please select a motor which has an oil seal on the output shaft. Table

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31 Tooth profile Rotational direction and reduction ratio Rating table definitions Life Torque limits Product sizing and selection Lubrication Torsional stiffness Positional accuracy Vibration Starting torque Backdriving torque No-load running torque Efficiency Design guidelines Assembly guidelines Checking output bearing S tooth profile Cup style Silk hat style Pancake style Grease lubricant Precautions on using Harmonic Grease B No. Oil lubricant Lubricant for special environments Design guideline Bearing support of the input and output shafts Wave Generator Sealing Assembly Precautions "dedoidal" state Checking procedure How to calculate the maximum moment load How to calculate the average load How to calculate the radial load coefficient (X) and axial load coefficient (Y) How to calculate life How to calculate the life under oscillating movement How to calculate the static safety coefficient

32 Tooth Profile S tooth profile Harmonic Drive developed a unique gear tooth profile that optimizes the tooth engagement. It has a special curved surface unique to the S tooth profile that allows continuous contact with the tooth profile. It also alleviates the concentration of stress by widening the width of the tooth groove against the tooth thickness and enlarging the radius on the bottom. This tooth profile (the S tooth ) enables up to % of the total number of teeth to be engaged simultaneously. Additionally the large tooth root radius increases the tooth strength compared with an involute tooth. This technological innovation results in high torque, high torsional stiffness, long life and smooth rotation. *Patented Engaged route of teeth Conventional tooth profile Fig. 9-1 Engaged area of teeth Fig. 9- S tooth profile Beginning of engagement Optimum engaged status 9

33 Rotational direction and reduction ratio Cup Style Series: CSG, CSF, CSD, CSF-mini Rotational direction Fig Input * R indicates the reduction ratio value from the ratings table. Output (Note) Contact us if you use the product as Accelerator () and (). FS CS (1) Reducer Input: Wave Generator (WG) Output: Flexspline (FS) Fixed: Circular Spline (CS) WG i= ー 1 R () Reducer Input: Wave Generator Output: Circular Spline Fixed: Flexspline i= ー 1 R+1 () Reducer Input: Flexspline Output: Circular Spline Fixed: Wave Generator i= ー R R+1 7 () Overdrive Input: Circular Spline Output: Flexspline Fixed: Wave Generator i= ー R+1 R () Overdrive Input: Flexspline Output: Wave Generator Fixed: Circular Spline i= R () Overdrive Input: Circular Spline Output: Wave Generator Fixed: Flexspline i=r+1 (7) Differential When all of the wave generator, the flexspline and the circular spline rotate, combinations (1) through () are available. Silk hat Series: SHG, SHF, SHD Rotational direction Fig. 1-1 Input * R indicates the reduction ratio value from the ratings. table Output (Note) Contact us if you use the product as an overdrive of () or (). (1) Reducer Input: Wave Generator Output: Flexspline Fixed: Circular Spline i= ー 1 R () Reducer Input: Wave Generator Output: Circular Spline Fixed: Flexspline i= ー 1 R+1 () Reducer Input: Flexspline Output: Circular Spline Fixed: Wave Generator i= ー R R+1 7 () Overdrive Input: Circular Spline Output: Flexspline Fixed: Wave Generator i= ー R+1 R () Overdrive Input: Flexspline Output: Wave Generator Fixed: Circular Spline i= R () Overdrive Input: Circular Spline Output: Wave Generator Fixed: Flexspline i=r+1 (7) Differential When all of the wave generator, the flexspline and the circular spline rotate, Combinations (1) through () are available. 1

34 Pancake Series: FB and FR Rotational direction Fig Input Output (Note) Contact us if you use the product as Accelerator () and (). Output (1) Reducer Input: Wave Generator Output: Circular Spline D Fixed: Circular Spline S Input i= ー 1 R Output () Reducer Input: Wave Generator Output: Circular Spline S Fixed: Circular Spline D Input i= ー 1 R+1 Output Input () Reducer Input: Circular Spline D Output: Circular Spline S Fixed: Wave Generator i= ー R R+1 7 Output Input () Overdrive Input: Circular Spline S Output: Circular Spline D Fixed: Wave Generator i= ー R+1 R Input Output Input Output () Overdrive Input: Circular Spline S Output: Wave Generator Fixed: Circular Spline D i=r+1 () Overdrive Input: Circular Spline D Output: Wave Generator Fixed: Circular Spline S i= R (7) Differential When all of the Wave Generator, the Circular Spline S and the Circular Spline D rotate, Combinations (1) through () are available. Reduction ratio The reduction ratio is determined by the number of teeth of the Flexspline and the Circular Spline Number of teeth of the Flexspline: Number of teeth of the Circular Spline: Input: Wave Generator Output: Flexspline Fixed: Circular Spline Reduction ratio Zf Zc 1 i1 = = Input: Wave Generator Reduction 1 Output: Circular Spline i ratio = = Fixed: Flexspline R R1 indicates the reduction ratio value from the ratings table. R 1 Zf-Zc Zf Zc-Zf Zc Example Number of teeth of the Flexspline: Number of teeth of the Circular Spline: Input: Wave Generator Output: Flexspline Fixed: Circular Spline Input: Wave Generator Output: Circular Spline Fixed: Flexspline Reduction ratio Reduction ratio 1 - i1 = = = R i = = = R

35 Rating Table Definitions See the corresponding pages of each series for values. Rated torque Rated torque indicates allowable continuous load torque at rated input speed. Limit for Repeated Peak Torque (see Graph 1-1) During acceleration and deceleration the Harmonic Drive gear experiences a peak torque as a result of the moment of inertia of the output load. The table indicates the limit for repeated peak torque. Limit for Average Torque In cases where load torque and input speed vary, it is necessary to calculate an average value of load torque. The table indicates the limit for average torque. The average torque calculated must not exceed this limit. (calculation formula: Page 1) Limit for Momentary Peak Torque (see Graph 1-1) The gear may be subjected to momentary peak torques in the event of a collision or emergency stop. The magnitude and frequency of occurrence of such peak torques must be kept to a minimum and they should, under no circumstance, occur during normal operating cycle. The allowable number of occurrences of the momentary peak torque may be calculated by using formula 1-1. Maximum Average Input Speed Maximum Input Speed Do not exceed the allowable rating. (calculation formula of the average input speed: Page 1). Example of application motion profile + Load torque + Wave Generator rotational speed Start Steady Stop (Speed cycle) Start Abnormal impact torque Time Load Torque Repeated Peak Torque Time Graph 1-1 Momentary Peak Torque Moment of Inertia The rating indicates the moment of inertia reflected to the gear input. Life Life of the wave generator The life of a gear is determined by the life of the wave generator bearing. The life may be calculated by using the input speed and the output load torque. Calculation formula for Rated Lifetime Ln Tr Nr Tav Nav Series name L1 CSF, CSD, SHF, SHD, CSF-mini 7, hours, hours Tr Lh=Ln Tav Life Nr Nav CSG, SHG 1, hours, hours L (average life) * Life is based on the input speed and output load torque from the rating table. Table 1-1 Formula 1-1 Life of L1 or L Rated torque Rated input speed Average load torque on the output side (calculation formula: Page 1) Average input speed (calculation formula: Page 1) Table 1- Relative torque rating 17 1 Load torque (when the rated torque is 1) Momentary peak torque Graph 1- Buckling torque Racheting torque Life of wave generator (L1) Fatigue strength of the flexspline Repeated peak torque 1 Rated torque Total number of input rotations * Lubricant life not taken into consideration in the graph described above. * Use the graph above as reference values. 1

36 Torque Limits Strength of flexspline The Flexspline is subjected to repeated deflections, and its strength determines the torque capacity of the Harmonic Drive gear. The values given for Rated Torque at Rated Speed and for the allowable Repeated Peak Torque are based on an infinite fatigue life for the Flexspline. The torque that occurs during a collision must be below the momentary peak torque (impact torque). The maximum number of occurrences is given by the equation below. Allowable limit of the bending cycles of the flexspline during rotation of the wave generator while the impact torque is applied: 1. x 1 (cycles) The torque that occurs during a collision must be below the momentary peak torque (impact torque). The maximum number of occurrences is given by the equation below. Calculation formula Caution N= 1. 1 n t Formula 1-1 Allowable occurances N occurances Time that impact torque is applied t sec Rotational speed of the wave generator n rpm The flexspline bends two times per one revolution of the wave generator. If the number of occurances is exceeded, the Flexspline may experience a fatigue failure. Ratcheting torque When excessive torque ( to 9 times rated torque) is applied while the gear is in motion, the teeth between the Circular Spline and Flexspline may not engage properly. This phenomenon is called ratcheting and the torque at which this occurs is called ratcheting torque. Ratcheting may cause the Flexspline to become non-concentric with the Circular Spline. Operating in this condition may result in shortened life and a Flexspline fatigue failure. * See the corresponding pages of each series for ratcheting torque values. * Ratcheting torque is affected by the stiffness of the housing to be used when installing the circular spline. Contact us for details of the ratcheting torque. Caution Caution When ratcheting occurs, the teeth may not be correctly engaged and become out of alignment as shown in Figure 1-1. Operating the drive in this condition will cause vibration and damage the flexspline. Once ratcheting occurs, the teeth wear excessively and the ratcheting torque may be lowered. Circular Spline Figure 1-1 Buckling torque When a highly excessive torque (1 to 17 times rated torque) is applied to the output with the input stationary, the flexspline may experience plastic deformation. This is defined as buckling torque. * See the corresponding pages of each series for buckling torque values. "Dedoidal" condition. Flexspline Warning When the flexspline buckles, early failure of the HarmonicDrive gear will occur. 1

37 Product Sizing & Selection In general, a servo system rarely operates at a continuous load and speed. The input rotational speed, load torque change and comparatively large torque are applied at start and stop. Unexpected impact torque may be applied. These fluctuating load torques should be converted to the average load torque when selecting a model number. As an accurate cross roller bearing is built in the direct external load support (output flange), the maximum moment load, life of the cross roller bearing and the static safety coefficient should Flowchart for selecting a size Please use the flowchart shown below for selecting a size. Operating conditions must not exceed the performance ratings. also be checked.+ Checking the application motion profile Review the application motion profile. Check the specifications shown in the figure below. Load torque Output rotational speed ーT1 T T T t1 t t t tn n1 n n n * n1, n and nn indicate the average values. nn Tn Time Time Graph 1-1 Calculate the average load torque applied on the output side from the application motion profile: Tav (Nm). Tav = n 1 t 1 T 1 +n t T + n n t n T n n 1 t 1 +n t + n n t n Make a preliminary model selection with the following conditions. Tav Limit for average torque torque (See the rating table of each series). Calculate the average output speed: no av (rpm) Obtain the reduction ratio (R). A limit is placed on ni max by motors. Calculate the average input rotational speed from the average output rotational speed (no av) and the reduction ratio (R): ni av (rpm) Calculate the maximum input rotational speed from the max. output rotational speed (no max) and the reduction ratio (R): ni max (rpm) Check whether the preliminary model number satisfies the following condition from the rating table. Ni av n 1 t 1 +n t + n n t n no av = t 1 + t + t n ni max R no max ni av = no av R ni max = no max R Limit for average speed (rpm) Ni max Limit for maximum speed (rpm) NG OK Obtain the value of each application motion profile. Load torque Tn (Nm) Time tn (sec) Output rotational speed nn (rpm) Check whether T1 and T are less than the repeated peak torque specification. OK NG Normal operation pattern Starting (acceleration) Steady operation (constant velocity) Stopping (deceleration) Dwell Maximum rotational speed Max. output speed Max. input rotational speed (Restricted by motors) Emergency stop torque When impact torque is applied T1, t1, n1 T, t, n T, t, n T, t, n no max ni max Ts, ts, ns Check whether Ts is less than the the momentary peak torque specification. Calculate (Ns) the allowable number of rotations during impact torque. OK 1 N S = N S 1. 1 n S R t OK NG NG Review the operation conditions and model number Required life L1 = L (hours) Calculate the lifetime. L 1 = 7 ( ) ( ) (hours) OK Tr Tav nr ni av Check whether the calculated life is equal to or more than the life of the wave generator (see Page 1). The model number is confirmed. NG 1

38 Example of model number selection Value of each application motion profile Load torque T(Nm) n Time t(sec) n Output speed n(rpm) n Maximum rotational speed Max. output speed Max. input speed (Restricted by motors) no max = 1 rpm ni max = 1 rpm Normal operation pattern Starting (acceleration) T1 = Nm, t1 =.sec, n1 = 7rpm Steady operation (constant velocity) T = Nm, t = sec, n = 1rpm Stopping (deceleration) T = Nm, t =.sec, n = 7rpm Dwell T = Nm, t =. sec, n = rpm Emergency stop torque When impact torque is applied Required life Ts = Nm, ts =.1 sec, ns = 1 rpm L 1 = 7 (hours) Calculate the average load torque to the output side based on the application motion profile: Tav (Nm). Tav = 7 rpm. sec Nm +1 rpm sec Nm +7 rpm. sec Nm 7 rpm. sec+1 rpm sec+7 rpm. sec Make a preliminary model selection with the following conditions. Tav = 19 Nm Nm (Limit for average torque for model number CSF--1-A-GR: See the rating table on Page 9.) Thus, CSF--1-A-GR is tentatively selected. Calculate the average output rotational speed: no av (rpm) Obtain the reduction ratio (R). Calculate the average input rotational speed from the average output rotational speed (no av) and the reduction ratio (R): ni av (rpm) Calculate the maximum input rotational speed from the maximum output rotational speed (no max) and the reduction ratio (R): ni max (rpm) 7 rpm. sec+1 rpm sec+7 rpm. sec no av = = 1 rpm. sec + sec +. sec +. sec 1 rpm = rpm ni av = 1 rpm 1 = 1 rpm ni max = 1 rpm 1 = 1 rpm Check whether the preliminary selected model number satisfies the following condition from the rating table. Ni av = 1 rpm rpm (Max average input speed of size ) Ni max = 1 rpm rpm (Max input speed of size ) OK NG Check whether T1 and T are equal to or less than the repeated peak torque specification. T1 = Nm 17 Nm (Limit of repeated peak torque of size ) T = Nm 17 Nm (Limit of repeated peak torque of size ) OK NG Check whether Ts is equal to or less than the momentary peak torque specification. Ts = Nm 11 Nm (Limit for momentary torque of size ) Calculate the allowable number (Ns) rotation during impact torque and confirm 1. 1 Calculate the lifetime. OK OK OK 1 N S == rpm 1.1 sec L 1 = 7 ( ) 9 Nm 19 Nm ( ) rpm 1 rpm (hours) Check whether the calculated life is equal to or more than the life of the wave generator (see Page 1). L 1 =71 hours 7 (life of the wave generator: L1) The selection of model number CSF--1-A-GR is confirmed from the above calculations. NG NG NG Review the operation conditions, size and reduction ratio 1