JP6441070B2 - Reduction gear design method - Google Patents

Description

  The present invention relates to a reduction gear having a mechanism as an eccentric oscillating gear device.

  Various speed reducers are used in various technical fields such as industrial robots and machine tools (see Patent Document 1). Patent Document 1 discloses a reduction gear including a cylindrical casing, a swing gear that swings within the casing, and a crank assembly that swings the swing gear. Based on the technology disclosed in Patent Document 1, the designer can design various reduction gears so as to meet the performance required by the customer (for example, torque and reduction ratio).

JP 2010-286098 A

  If the designer designs various reducers according to different customer requirements, the designer needs to perform design calculations on various parts of the reducer and create various drawings. . This results in excessive design effort.

  An object of this invention is to provide the technique which contributes to the reduction of the effort regarding the design of a reduction gear.

According to another aspect of the design method of the present invention, in the distance relationship between the rotation center axis of the output unit and the transmission rotation axis of the crank assembly that rotates the output unit around the rotation center axis, It is used to design a reducer that is different from the reducer. The design method includes a first design step of designing a first crank assembly as the crank assembly, and a second design step of designing a first output portion that rotates around a first main axis defined as the rotation center axis. And comprising. The other another speed reducer performs a rotational motion around the second transmission axis defined as the transmission rotation axis that is separated from the second main axis defined as the rotation center axis by a second distance, thereby A second crank assembly for rotating the second output portion around the second main shaft is provided. The second crank assembly includes a second transmission gear that rotates around the second transmission shaft, and a second crankshaft to which the second transmission gear is attached. The first design step includes designing a first transmission gear that matches the second transmission gear in terms of modules and shift coefficients. The second design step includes determining a first distance between the first main shaft and a first transmission shaft defined as the transmission rotation shaft from the module and the dislocation coefficient. The first distance is different from the second distance.

  According to the above configuration, the first transmission gear matches the second transmission gear in terms of the module and the shift coefficient. Therefore, the design data used for designing the second transmission gear is used for designing the first transmission gear. Is possible. Therefore, the labor involved in designing the first transmission gear is reduced.

  The present invention contributes to a reduction in labor related to the design of a reduction gear.

It is a schematic sectional drawing of the reduction gear of 1st Embodiment. It is a side view of the reduction gear shown by FIG. 1A. It is a schematic sectional drawing of another reduction gear. It is a side view of the reduction gear shown by FIG. 2B. It is a flowchart showing the example design procedure of the reduction gear shown by FIG. 1A and 2A (3rd Embodiment). It is a schematic front view of a transmission gear (4th Embodiment). It is a schematic sectional drawing of a transmission gear (fifth embodiment). It is a schematic sectional drawing of a transmission gear (6th Embodiment). It is a conceptual diagram of a driving force transmission path (seventh embodiment). It is a conceptual diagram of a driving force transmission path (seventh embodiment). It is a conceptual diagram of a driving force transmission path (seventh embodiment).

  Various embodiments relating to techniques that contribute to reducing the design effort of a reducer will be described with reference to the accompanying drawings.

<First Embodiment>
In a conventional design technique, a designer has a plurality of reduction gears that are different from each other in a distance relationship between a rotation center axis of an output unit that rotates at a predetermined reduction ratio and a crank assembly that transmits driving force to the output unit. When designing the machine, the designer designs a dedicated transmission gear for each of the plurality of reduction gears. As a result, enormous types of transmission gears are created. The inventors have studied various speed reducer designs, and the transmissions that are consistent in module and shift coefficient for multiple speed reducers that differ in the distance between the center axis of rotation of the output and the crank assembly. We found that gears are applicable. In the first embodiment, two reduction gears incorporating transmission gears that match in module and shift coefficient are described.

(Reduction gear structure)
1A and 1B show an exemplary speed reducer 100. FIG. FIG. 1A is a schematic cross-sectional view of the speed reducer 100. FIG. 1B is a side view of the speed reducer 100. The speed reducer 100 will be described with reference to FIGS. 1A and 1B.

  The speed reducer 100 includes a casing cylinder 200, a gear portion 300, and three crank assemblies 400 (see FIG. 1B: FIG. 1A shows one of the three crank assemblies 400). The housing cylinder 200 accommodates the gear unit 300 and the three crank assemblies 400. In the present embodiment, the first speed reducer is exemplified by the speed reducer 100.

  The housing cylinder 200 includes an outer cylinder part 210, a carrier part 220, and two main bearings 230. The carrier part 220 is disposed in the outer cylinder part 210. The two main bearings 230 are disposed between the outer cylinder part 210 and the carrier part 220. The two main bearings 230 allow relative rotational movement between the outer cylinder part 210 and the carrier part 220. In the present embodiment, the first output part is exemplified by one of the outer cylinder part 210 and the carrier part 220.

  FIG. 1A shows a main shaft FMX defined as the rotation center axis of two main bearings 230. The outer cylinder part 210 and the carrier part 220 surround the main shaft FMX. If the outer cylinder part 210 is fixed, the carrier part 220 rotates around the main axis FMX. If carrier part 220 is fixed, outer cylinder part 210 rotates around main axis FMX. That is, one of the outer cylinder part 210 and the carrier part 220 can rotate around the main axis FMX relative to the other of the outer cylinder part 210 and the carrier part 220. In the present embodiment, the first main axis is exemplified by the main axis FMX.

  The designer can give the outer cylinder part 210 various shapes. Therefore, the principle of the present embodiment is not limited to a specific shape of the outer cylinder part 210.

  The designer can give the carrier portion 220 various shapes. Therefore, the principle of this embodiment is not limited to a specific shape of the carrier part 220.

  The outer cylinder part 210 includes an outer cylinder 211 and a plurality of internal tooth pins 212. The outer cylinder 211 defines a cylindrical internal space in which the carrier part 220, the gear part 300, and the crank assembly 400 are accommodated. Each internal tooth pin 212 is a cylindrical member extending substantially parallel to the main shaft FMX. Each internal tooth pin 212 is fitted into a groove formed in the inner wall of the outer cylinder 211. Therefore, each internal tooth pin 212 is appropriately held by the outer cylinder 211.

  The plurality of internal teeth pins 212 are arranged at substantially constant intervals around the main axis FMX. A half circumferential surface of each internal tooth pin 212 protrudes from the inner wall of the outer cylinder 211 toward the main shaft FMX. Therefore, the plurality of internal teeth pins 212 function as internal teeth that mesh with the gear portion 300.

  The carrier part 220 includes a base part 221, an end plate part 222, positioning pins 223, and fixing bolts 224. The carrier part 220 has a cylindrical shape as a whole. The base portion 221 includes a base plate portion 225 and three shaft portions 226 (one of the three shaft portions 226 is shown in FIG. 1A). Each of the three shaft portions 226 extends from the substrate portion 225 toward the end plate portion 222. A screw hole and a reamer hole are formed in the tip surface of each of the three shaft portions 226. The positioning pin 223 is inserted into the reamer hole. As a result, the end plate portion 222 is accurately positioned with respect to the base portion 221. The fixing bolt 224 is screwed into the screw hole. As a result, the end plate part 222 is appropriately fixed to the base part 221.

  The gear unit 300 is disposed between the substrate unit 225 and the end plate unit 222. The three shaft portions 226 penetrate the gear portion 300 and are connected to the end plate portion 222.

  The gear unit 300 includes two gears 310 and 320. The gear 310 is disposed between the substrate unit 225 and the gear 320. The gear 320 is disposed between the end plate portion 222 and the gear 310.

  The gear 310 is substantially equal to the gear 320 in shape and size. The gears 310 and 320 rotate around the outer cylinder 211 while meshing with the inner tooth pins 212. Accordingly, the centers of the gears 310 and 320 perform a swinging motion that goes around the main axis FMX.

  The rotation phase of the gear 310 is shifted from the rotation phase of the gear 320 by approximately 180 °. While the gear 310 meshes with half of the plurality of internal teeth pins 212 of the outer cylinder portion 210, the gear 320 meshes with the remaining half of the plurality of internal teeth pins 212. Therefore, the gear part 300 can rotate the outer cylinder part 210 or the carrier part 220.

  In the present embodiment, the gear unit 300 includes two gears 310 and 320. Alternatively, the designer may use more than two gears as the gear portion. Further alternatively, the designer may use one gear as the gear portion.

  Each of the three crank assemblies 400 includes a crankshaft 410, four bearings 421, 422, 423, 424, and a transmission gear 430. The transmission gear 430 may be a general spur gear. Alternatively, the transmission gear 430 may be another type of gear. The principle of this embodiment is not limited to a specific type of transmission gear 430.

  FIG. 1A shows the transmission shaft FTX. The transmission shaft FTX is substantially parallel to the main shaft FMX. The crankshaft 410 rotates around the transmission shaft FTX. FIG. 1A shows the distance between the transmission shaft FTX and the main shaft FMX with the symbol “L1”. In the present embodiment, the first crank assembly is illustrated by one of the three crank assemblies 400. The first transmission shaft is exemplified by the transmission shaft FTX. The first distance is exemplified by the distance L1.

  FIG. 1B shows a virtual circle PC1 drawn around the main axis FMX. The radius of the virtual circle PC1 is equal to the distance L1 described with reference to FIG. 1A. The three transmission shafts FTX corresponding to the three crankshafts 410 are positioned on the virtual circle PC1.

  The crankshaft 410 includes two journals 411 and 412 and two eccentric portions 413 and 414. The journals 411 and 412 extend along the transmission axis FTX. The central axes of the journals 411 and 412 coincide with the transmission axis FTX. The journals 411 and 412 rotate around the transmission axis FTX. The eccentric parts 413 and 414 are formed between the journals 411 and 412. Each of the eccentric portions 413 and 414 is eccentric from the transmission shaft FTX. In the present embodiment, the first crankshaft is exemplified by the crankshaft 410.

  The journal 411 is inserted into the bearing 421. The bearing 421 is disposed between the journal 411 and the end plate portion 222. Therefore, the journal 411 is supported by the end plate portion 222 and the bearing 421. The transmission gear 430 is attached to the journal 411. Therefore, the transmission gear 430 can rotate around the transmission axis FTX together with the journal 411. In the present embodiment, the first transmission gear is exemplified by the transmission gear 430.

  The journal 412 is inserted into the bearing 422. The bearing 422 is disposed between the journal 412 and the base 221. Therefore, the journal 412 is supported by the base 221 and the bearing 422.

  The eccentric part 413 is inserted into the bearing 423. The bearing 423 is disposed between the eccentric portion 413 and the gear 310. The eccentric part 414 is inserted into the bearing 424. The bearing 424 is disposed between the eccentric portion 414 and the gear 320.

  FIG. 1A shows the central gear shaft GS1. The central gear shaft GS1 rotates around the main axis FMX. The central gear shaft GS1 may be a part of a drive source (motor). Alternatively, a member formed separately from the drive source may be used. The principle of this embodiment is not limited to a specific structure of the central gear shaft GS1.

  The central gear shaft GS1 meshes with each of the three transmission gears 430. As a result, the driving force generated by the driving source is transmitted from the central gear shaft GS1 to each of the three transmission gears 430. When a driving force is input to the transmission gear 430, the crankshaft 410 rotates around the transmission axis FTX. As a result, the eccentric portions 413 and 414 rotate eccentrically around the transmission shaft FTX. The crankshaft 410 transmits a driving force to the gears 310 and 320 via the bearings 423 and 424. The gears 310 and 320 connected to the eccentric parts 413 and 414 via the bearings 423 and 424 oscillate in a circular space defined by the outer cylinder part 210. Since the gears 310 and 320 mesh with the inner tooth pin 212, a relative rotational motion is caused between the outer cylinder part 210 and the carrier part 220.

(Another reduction gear)
Based on the design principle of the speed reducer 100 described with reference to FIGS. 1A and 1B, the designer can design another speed reducer that differs in the distance between the main shaft and the transmission shaft. it can.

  2A and 2B show another reduction gear 100A constructed based on the design principle described with reference to FIGS. 1A and 1B. FIG. 2A is a schematic cross-sectional view of the speed reducer 100A. FIG. 2B is a side view of the speed reducer 100A. The reduction gear 100A will be described with reference to FIGS. 1A to 2B.

  The speed reducer 100A includes a casing cylinder 200A, a gear portion 300A, and three crank assemblies 400A (see FIG. 2B: FIG. 2A shows one of the three crank assemblies 400A). The casing cylinder 200A accommodates the gear portion 300A and the crank assembly 400A. In the present embodiment, the second speed reducer is exemplified by a speed reducer 100A.

  The housing cylinder 200A includes an outer cylinder part 210A, a carrier part 220A, and two main bearings 230A. The carrier part 220A is disposed in the outer cylinder part 210A. The two main bearings 230A are arranged between the outer cylinder part 210A and the carrier part 220A. The two main bearings 230A allow relative rotational movement between the outer cylinder part 210A and the carrier part 220A. In the present embodiment, the second output part is exemplified by one of the outer cylinder part 210A and the carrier part 220A.

  FIG. 2A shows a main shaft SMX defined as the rotation center axis of two main bearings 230A. If outer cylinder part 210A is fixed, carrier part 220A rotates around main axis SMX. If carrier part 220A is fixed, outer cylinder part 210A rotates around main axis SMX. That is, one of the outer cylinder part 210A and the carrier part 220A can be rotated around the main axis SMX relative to the other of the outer cylinder part 210A and the carrier part 220A. In the present embodiment, the second main axis is exemplified by the main axis SMX.

  The designer can give various shapes to the outer cylindrical portion 210A. Therefore, the principle of the present embodiment is not limited to a specific shape of the outer cylinder portion 210A.

  The designer can give various shapes to the carrier part 220A. Therefore, the principle of this embodiment is not limited to a specific shape of the carrier portion 220A.

  The outer cylinder portion 210A includes an outer cylinder 211A and a plurality of internal tooth pins 212A. There may be more internal tooth pins 212 </ b> A in the speed reducer 100 </ b> A than the internal tooth pins 212 in the speed reducer 100. The outer cylinder 211A defines a cylindrical inner space in which the carrier part 220A, the gear part 300A, and the crank assembly 400A are accommodated. Each internal tooth pin 212A is a cylindrical member extending substantially parallel to the main shaft SMX. Each internal tooth pin 212A is fitted into a groove formed on the inner wall of the outer cylinder 211A. Therefore, each internal tooth pin 212A is appropriately held by the outer cylinder 211A.

  The plurality of internal teeth pins 212A are arranged at substantially constant intervals around the main axis SMX. The half circumferential surface of each internal tooth pin 212A protrudes from the inner wall of the outer cylinder 211A toward the main shaft SMX. Accordingly, the plurality of internal teeth pins 212A function as internal teeth that mesh with the gear portion 300A.

  The carrier portion 220A includes a base portion 221A and an end plate portion 222A. The carrier part 220A has a cylindrical shape as a whole. The base portion 221A includes a base plate portion 225A and three shaft portions 226A (one of the three shaft portions 226A is shown in FIG. 2A). The shaft portion 226A extends from the substrate portion 225A toward the end plate portion 222A. Similarly to the speed reducer 100A, the end plate portion 222A may be fixed to the distal end surface of the shaft portion 226A with screws and pins.

  The gear portion 300A is disposed between the substrate portion 225A and the end plate portion 222A. The shaft portion 226A passes through the gear portion 300A and is connected to the end plate portion 222A.

  The gear unit 300A includes two gears 310A and 320A. The gear 310A is disposed between the board portion 225A and the gear 320A. The gear 320A is disposed between the end plate portion 222A and the gear 310A.

  The gear 310A is similar to the gear 320A in shape and size. The gears 310A and 320A move around the outer cylinder 211A while meshing with the inner tooth pins 212A. Therefore, the centers of the gears 310A and 320A go around the main axis SMX.

  The rotation phase of the gear 310A is shifted by approximately 180 ° from the rotation phase of the gear 320A. While the gear 310A meshes with half of the plurality of internal teeth pins 212A of the outer cylinder portion 210A, the gear 320A meshes with the remaining half of the plurality of internal teeth pins 212A. Therefore, the gear part 300A can rotate the outer cylinder part 210A or the carrier part 220A.

  In the present embodiment, the gear unit 300A includes two gears 310A and 320A. Alternatively, the designer may use more than two gears as the gear portion. Further alternatively, the designer may use one gear as the gear portion.

  The crank assembly 400A includes a crankshaft 410A, four bearings 421A, 422A, 423A, and 424A, and a transmission gear 430A. The transmission gear 430A may be a general spur gear. Alternatively, the transmission gear 430A may be another type of gear. The principle of this embodiment is not limited to a specific type of transmission gear 430A.

  FIG. 2A shows the transmission shaft STX. The transmission axis STX is substantially parallel to the main axis SMX. The crankshaft 410A rotates around the transmission shaft STX. FIG. 2A shows the distance between the transmission shaft STX and the main shaft SMX with the symbol “L2”. The distance L2 is larger than the distance L1. In the present embodiment, the second crank assembly is exemplified by the crank assembly 400A. The second transmission shaft is exemplified by the transmission shaft STX. The second distance is exemplified by the distance L2.

  FIG. 2B shows a virtual circle PC2 drawn around the main axis SMX. The radius of the virtual circle PC2 is equal to the distance L2 described with reference to FIG. 2A. Three transmission shafts STX corresponding to the three crankshafts 410A are positioned on the virtual circle PC2.

  The crankshaft 410A includes two journals 411A and 412A and two eccentric portions 413A and 414A. The journals 411A and 412A extend along the transmission axis STX. The central axes of the journals 411A and 412A coincide with the transmission axis STX. The journals 411A and 412A rotate around the transmission axis STX. The eccentric portions 413A and 414A are formed between the journals 411A and 412A. Each of the eccentric portions 413A and 414A is eccentric from the transmission shaft STX.

  The journal 411A is inserted into the bearing 421A. The bearing 421A is disposed between the journal 411A and the end plate portion 222A. Therefore, the journal 411A is supported by the end plate portion 222A and the bearing 421A. The transmission gear 430A is attached to the journal 411A. Therefore, the transmission gear 430A can rotate around the transmission axis STX together with the journal 411A. In the present embodiment, the second transmission gear is exemplified by the transmission gear 430A.

  The journal 412A is inserted into the bearing 422A. The bearing 422A is disposed between the journal 412A and the base 221A. Therefore, the journal 412A is supported by the base 221A and the bearing 422A.

  The eccentric portion 413A is inserted into the bearing 423A. The bearing 423A is disposed between the eccentric portion 413A and the gear 310A. The eccentric portion 414A is inserted into the bearing 424A. The bearing 424A is disposed between the eccentric portion 414A and the gear 320A.

  FIG. 2A shows the central gear shaft GS2. The central gear shaft GS2 rotates around the main axis SMX. The central gear shaft GS2 may be a part of a drive source (motor). Alternatively, a member formed separately from the drive source may be used. The principle of this embodiment is not limited to a specific structure of the central gear shaft GS2.

  The central gear shaft GS2 meshes with each of the three transmission gears 430A. As a result, the driving force generated by the driving source is transmitted from the central gear shaft GS2 to each of the three transmission gears 430A. When driving force is input to the transmission gear 430A, the crankshaft 410A rotates around the transmission shaft STX. As a result, the eccentric portions 413A and 414A rotate eccentrically around the transmission shaft STX. The gears 310A and 320A connected to the eccentric portions 413A and 414A via the bearings 423A and 424A swing within a circular space defined by the outer cylinder portion 210A. Since the gears 310A and 320A mesh with the internal tooth pin 212A, a relative rotational motion is caused between the outer cylinder portion 210A and the carrier portion 220A.

  The designer may design the speed reducer 100 after designing the speed reducer 100A. At this time, the designer may make the module and the dislocation coefficient of the transmission gear 430 coincide with the module and the dislocation coefficient of the transmission gear 430A. Thereafter, the designer may calculate the distance L1 from the module used and the dislocation coefficient.

Second Embodiment
The designer can determine the distance between the main shaft and the transmission shaft from the module and the dislocation coefficient using various methods. In the second embodiment, an exemplary technique for determining the distance between the main shaft and the transmission shaft is described.

  If different reduction ratios are required for the reducer 100 described with reference to FIG. 1A and the reducer 100A described with reference to FIG. 2A, generally the number of teeth on the central gear shaft GS1 and The sum of the number of teeth of the transmission gear 430 is different from the sum of the number of teeth of the central gear shaft GS2 and the number of teeth of the transmission gear 430A. If the designer sets the shift coefficient to zero for each of the reduction gears 100 and 100A, the relationship between the distance from the main shaft to the transmission shaft and the sum of the number of teeth is expressed by the following mathematical formula.

  If the designer sets the dislocation coefficient to a positive or negative value different from zero, the above formula may be modified in consideration of the dislocation coefficient.

  The following table shows the relationship between the sum of the number of teeth and the distance from the main shaft to the transmission shaft when the designer sets the module to “1.5” and sets the dislocation coefficient to zero.

  If the designer sets the sum of the number of teeth of the central gear shaft GS1 and the number of teeth of the transmission gear 430 with respect to the speed reducer 100 to “54”, the distance L1 from the main shaft FMX to the transmission shaft FTX is “40. 50 mm ". If the designer sets the sum of the number of teeth of the central gear shaft GS2 and the number of teeth of the transmission gear 430A to “60” with respect to the reduction gear 100A, the distance L2 from the main shaft SMX to the transmission shaft STX is “45. 00mm ".

<Third Embodiment>
The designer can design the speed reducer in various procedures using the design technique described in relation to the second embodiment. In the third embodiment, an exemplary design procedure of the speed reducer will be described.

  FIG. 3 is a flowchart showing an exemplary design procedure of the speed reducer. With reference to FIG. 3, the design procedure of a reduction gear is demonstrated.

(Step S110)
As described in connection with the second embodiment, the designer determines the module and the dislocation coefficient. Thereafter, step S120 is executed.

(Step S120)
The designer may search the design database and verify whether there is design data of the transmission gear that matches in module and shift coefficient. If there is design data of the transmission gear that matches in module and shift coefficient, step S130 is executed. In other cases, step S180 is executed.

(Step S130)
The designer extracts from the design database design data of the transmission gear that matches in module and shift coefficient. Thereafter, step S140 is executed.

(Step S140)
The designer determines the number of teeth of the central gear shaft so that the reduction ratio required for the reduction gear can be obtained. Thereafter, step S150 is executed.

(Step S150)
The designer may perform strength calculation on the transmission gear obtained in step S120. If the transmission gear has sufficient mechanical strength under the use condition of the reduction gear, step S160 is executed. In other cases, step S190 is executed.

(Step S160)
The designer determines the distance between the main shaft and the transmission shaft based on the technique described in relation to the second embodiment. Thereafter, step S170 is executed.

(Step S170)
The designer designs the outer cylinder part, the carrier part, and the gear part on the basis of the distance obtained in step S160.

(Step S180)
The designer redesigns the transmission gear. Thereafter, step S140 is executed.

(Step S190)
The designer increases the thickness of the transmission gear. As a result, a transmission gear having higher mechanical strength than the existing transmission gear is designed. Thereafter, step S150 is executed.

  In the present embodiment, the first design process is exemplified by the design procedure of steps S110 to S160. The second design process is exemplified by steps S160 and S170.

<Fourth embodiment>
If the design procedure described in connection with the third embodiment is used, the designer can design the speed reducer without changing the number of teeth of the existing transmission gear. In addition, as described in connection with the various embodiments described above, the transmission gear module and shift coefficient of the new reduction gear are set to be the same as those of the existing transmission gear, so that the outer contour of the transmission gear is Therefore, it matches the outer contour of the existing transmission gear. In 4th Embodiment, the transmission gear obtained based on the design procedure demonstrated in relation to 3rd Embodiment is demonstrated.

  FIG. 4 is a schematic front view of the transmission gears 430B and 430C. With reference to FIG.3 and FIG.4, the geometrical commonality of the transmission gears 430B and 430C is demonstrated.

  In step S130 (see FIG. 3), the designer acquires design data of the transmission gear 430B. In the subsequent step S140, the designer achieves the reduction ratio required for the new reduction gear by adjusting the number of teeth of the central gear shaft, so that the new transmission gear 430C is replaced with the existing transmission gear. It can have as many teeth as 430B.

  FIG. 4 shows the outer contour ECT of the transmission gear 430B and the outer contour NCT of the transmission gear 430C. As described above, the transmission gear 430C matches the transmission gear 430B in terms of the number of teeth, the module, and the shift coefficient, so the closed region drawn by the outer contour line NCT is the closed region drawn by the outer contour line ECT in shape and size. Matches.

<Fifth Embodiment>
If the design procedure described in connection with the third embodiment is used, the designer can use the existing transmission gear as it is for another reduction gear. In the fifth embodiment, a transmission gear obtained based on the design procedure described in relation to the third embodiment will be described.

  FIG. 5 is a schematic cross-sectional view of the transmission gears 430B and 430C. With reference to FIG. 3 thru | or FIG. 5, the geometrical commonality of the transmission gears 430B and 430C is demonstrated.

  In step S150 (see FIG. 3), the designer verifies whether or not the mechanical strength of the existing transmission gear 430B has sufficient mechanical strength under the new use condition of the reduction gear. If the mechanical strength of the transmission gear 430B has sufficient mechanical strength under the new speed reducer usage conditions, the designer can set the thickness T2 of the transmission gear 430C used in the new speed reducer to the transmission gear 430B. Can be made to coincide with the thickness T1. In this case, the transmission gear 430C coincides in shape with the transmission gear 430B.

<Sixth Embodiment>
As described in connection with the first embodiment, the crankshaft is inserted into the transmission gear. Therefore, an insertion hole is formed in the transmission gear. The insertion hole may be adapted to the cross-sectional shape of the spline shaft portion included in the crankshaft. Alternatively, the insertion hole may be adapted to the cross-sectional shape of the crankshaft and a key assembly attached to the crankshaft. If the insertion hole is matched between the transmission gears used in existing and new reducers, not only the design department designing the reducer but also the logistics department managing the production of the reducer Is greatly reduced. In the sixth embodiment, two transmission gears that coincide in the shape of the insertion hole will be described.

  FIG. 6 is a schematic front view of the transmission gears 430D and 430E. The code | symbol used in common between 4th Embodiment and 6th Embodiment means that the element to which the said common code | symbol was attached | subjected has the same function as 4th Embodiment. With reference to FIG. 6, the commonality of the transmission gears 430D and 430E will be described.

  Similar to the fourth embodiment, FIG. 6 shows outer contour lines ECT and NCT representing the outer shapes of the transmission gears 430D and 430E. The closed region drawn by the outer contour line NCT coincides with the closed region drawn by the outer contour line ECT in shape and size.

  A spline hole 431D is formed in the transmission gear 430D. A spline hole 431E is formed in the transmission gear 430E. The spline hole 431E coincides with the spline hole 431D in shape and size. In the present embodiment, the first insertion hole is exemplified by one of the spline holes 431D and 431E. The second insertion hole is exemplified by the other of the spline holes 431D and 431E.

<Seventh embodiment>
Various paths may be set for transmission of driving force from a driving source (for example, a motor) to the reduction gear. In the sixth embodiment, various driving force transmission paths will be described.

  7A to 7C are conceptual diagrams of driving force transmission paths. The driving force transmission path will be described with reference to FIGS. 1A and 7A to 7C.

  7A to 7C each show three transmission gears 430F. The transmission gear 430F may be designed based on the design procedure described in relation to the third embodiment.

  7A to 7C each show a drive gear DG. The drive gear DG is closest to the drive source among the plurality of gears shown in FIGS. 7A to 7C. That is, the drive gear DG is located on the most upstream side in the drive force transmission path. 7A to 7C, the drive gear DG is shaded.

  With respect to the transmission path shown in FIG. 7A, like the central gear shaft GS1 described with reference to FIG. 1A, the drive gear DG can mesh with each of the three transmission gears 430F.

  FIG. 7B shows a central gear CG that meshes with each of the three transmission gears 430F. The drive gear DG may mesh with one of the three transmission gears 430F. In this case, the other transmission gear 430F can receive the driving force through the central gear CG.

  FIG. 7C shows the central gear CG, similar to FIG. 7B. The drive gear DG may mesh with the central gear CG. In this case, each of the three transmission gears 430F can receive a driving force through the central gear CG.

  The principles of the various embodiments described above may be combined to meet the requirements for a reducer.

  The principle of the above-described embodiment is suitably used for various speed reducer designs.

100, 100A ... Reducer 210, 210A ... Outer cylinder Part 220, 220A ... Carrier part 310, 310A ... Gear 320, 320A ... Gears 400, 400A ... Crank assembly 410, 410A ... crankshaft 430-430F ... transmission gear 431D, 431E ····························································· Spindle FTX , STX ... ............. transmission shaft

Claims (1)

A speed reducer design method that differs from another speed reducer in the distance relationship between the rotation center axis of the output section and the transmission rotation axis of the crank assembly that rotates the output section about the rotation center axis Because
A first design step of designing a first crank assembly as the crank assembly;
A second design step of designing a first output section that rotates around a first main axis defined as the rotation center axis,
The other another speed reducer performs a rotational motion around the second transmission axis defined as the transmission rotation axis that is separated from the second main axis defined as the rotation center axis by a second distance, thereby A second crank assembly for rotating the second output portion around the second main axis;
The second crank assembly includes a second transmission gear that rotates around the second transmission shaft, and a second crankshaft to which the second transmission gear is attached,
The first design step includes designing a first transmission gear that matches the second transmission gear in terms of module and shift coefficient;
The second design step includes a step of determining a first distance between the first main shaft and a first transmission shaft defined as the transmission rotation shaft from the module and the dislocation coefficient,
The first distance is different from the second distance. A reduction gear design method.