speed reducer

Abstract

Suppresses noise generated in the reducer. [Solution] The reducer includes a case, a carrier, and an input gear including a first part and a second part made of different materials, and a reduction section that reduces the rotation input to the input gear and outputs it as relative rotation of either the case or the carrier relative to the other.

Description

[Technical Field]

[0001] The present invention relates to a reducer. [Background technology]

[0002] As disclosed in Patent Document 1, an eccentric oscillating reducer is known. This reducer has a crankshaft with an eccentric body and an input gear fixed to the crankshaft. Rotation is input to the input gear from a drive gear fixed to the output shaft of a motor. The input of rotation from the drive gear to the input gear results in a first stage of reduction in speed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2023-066464 Summary of the Invention [Problem to be solved by the invention]

[0004] The input gear is subjected to high-speed rotation and high surface pressure from the drive gear driven by the motor. For this reason, steel is typically used as the material for the input gear. However, steel has poor vibration damping properties and is a source of noise. Furthermore, resonance can further increase the noise. The present invention was made in consideration of these points, and aims to suppress noise in an eccentric oscillating reducer. [Means for solving the problem]

[0005] A reducer according to one embodiment of the present invention includes: Case and a carrier rotatable relative to the case; The gearbox includes an input gear including a first portion and a second portion made of different materials, and a speed reduction section that reduces the speed of the rotation input to the input gear and outputs it as relative rotation between the case and the carrier. [Effects of the Invention]

[0006] According to the present invention, it is possible to suppress the generation of noise in the reducer. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view of a reducer for explaining an embodiment. [Figure 2] FIG. 2 is a cross-sectional view taken along line II in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line II-II in FIG. [Figure 4] FIG. 4 is a plan view showing a specific example of an input gear included in the reducer of FIG. [Figure 5] FIG. 5 is a plan view showing another specific example of the input gear included in the reducer of FIG. [Figure 6] FIG. 6 is a plan view showing another specific example of the input gear included in the reducer of FIG. [Figure 7] FIG. 7 is a plan view showing another specific example of the input gear included in the reducer of FIG. [Figure 8] FIG. 8 is a plan view showing another specific example of the input gear included in the reducer of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0008] One embodiment of the present disclosure is <1> ~ <16> Regarding.

[0009] <1> Case and Career and A reducer comprising: an input gear including a first portion and a second portion made of different materials; and a reduction section that reduces the speed of rotation input to the input gear and outputs the rotation as relative rotation of one of the case and the carrier with respect to the other.

[0010] <2> the speed reducer portion has a shaft member rotatably held by the carrier, the input gear has external teeth and a connection portion that connects to the shaft member, The first portion includes external teeth and the second portion includes a connecting portion. <1> The reducer according to claim 1.

[0011] <3> the speed reducer portion has a shaft member rotatably held by the carrier, the input gear has external teeth and a connection portion that connects to the shaft member, The first portion includes external teeth, and the second portion is located between the external teeth and the connecting portion. <1> The reducer according to claim 1.

[0012] <4> the input gear has a first portion including the connection portion, The second portion is located between the first portion including the external teeth and the first portion including the connecting portion. <3> The reducer according to claim 1.

[0013] <5> the input gear has a third portion including the connection portion, the material constituting the third portion is different from the material constituting the first portion and different from the material constituting the second portion; <3> The reducer according to claim 1.

[0014] <6> the input gear has a third portion located between the second portion and the connecting portion, the material constituting the third portion is different from the material constituting the first portion and different from the material constituting the second portion; <3> or <4> The reducer according to claim 1.

[0015] <7> The Young's modulus of the material constituting the first portion is greater than the Young's modulus of the material constituting the second portion. <1> ~ <6> The reducer according to any one of claims 1 to 4.

[0016] <8> the first portion comprises steel and the second portion comprises cast iron; <1> ~ <7> The reducer according to any one of claims 1 to 4.

[0017] <9> The first portion includes a metal, and the second portion includes a rubber or a resin. <1> ~ <7> The reducer according to any one of claims 1 to 4.

[0018] <10> a boundary between the first portion and the second portion including an inclined portion inclined with respect to a circumference centered on the rotation axis of the input gear; <1> ~ <9> The reducer according to any one of claims 1 to 4.

[0019] <11> The input gear is provided with a hole. <1> ~ <10> The reducer according to any one of claims 1 to 4.

[0020] <12> Case and Career and a reduction gear section that has an input gear having a hole and that receives rotation as an input, and that reduces the speed of the rotation input to the input gear and outputs the rotation as a relative rotation of one of the case and the carrier relative to the other.

[0021] <13> the speed reducer portion has a shaft member rotatably held by the carrier, the input gear has external teeth and a connection portion that connects to the shaft member, The hole is located between the external tooth and the connecting portion. <11> or <12> The reducer according to claim 1.

[0022] <14> A plurality of the holes are provided. <11> ~ <13> The reducer according to any one of claims 1 to 4.

[0023] <15> The speed reducer is a shaft member to which the input gear is fixed and which is rotatably held by the carrier; an external gear having external teeth that mesh with the internal teeth of the case and that is eccentrically oscillated by the shaft member; <1> ~ <14> The reducer according to any one of claims 1 to 4.

[0024] <16> The input gear functions as a planetary gear. <1> ~ <14> The reducer according to any one of claims 1 to 4.

[0025] An embodiment of the present invention will be described below with reference to the drawings. In the drawings accompanying this specification, the scale and aspect ratios have been appropriately changed and exaggerated from those of the actual objects for the sake of clarity and ease of understanding. Components shown in some drawings may be omitted in other drawings. The scale and aspect ratios may differ between the drawings.

[0026] Terms such as "parallel," "orthogonal," and "identical" that specify shapes, geometric conditions, and their degrees are not limited to their strict meanings. These terms should be interpreted to include a range of degrees within which similar functions can be expected.

[0027] Figures 1 to 8 are diagrams for explaining an embodiment of the present invention. Of these, Figure 1 is a cross-sectional view of a reducer 10. Figure 2 is a cross-sectional view of the reducer as viewed from the axial direction. Figure 3 is a cross-sectional view of the reducer in the axial direction, taken at a different plane from that of Figure 2. Figures 4 to 8 are plan views showing specific examples of input gears and their modified examples.

[0028] In the illustrated example, the input gear according to this embodiment is applied to an eccentric oscillating reducer. In the following, this embodiment will be described based on an eccentric oscillating reducer. However, the input gear according to this embodiment is not limited to eccentric oscillating reducers and can be applied to various reducers.

[0029] The reducer 10 shown in Fig. 1 is an eccentric oscillating reducer, as will be described below. However, the reducer 10 is not limited to the illustrated example, and may also be a planetary gear reducer. The reducer 10 has, as its main components, a case 20, a carrier 30, and a reduction unit 100. Below, the case 20, the carrier 30, and the reduction unit 100 will be described in detail in this order with reference to the illustrated specific example.

[0030] The case 20 has internal teeth 25. The internal teeth 25 are arranged in a circumferential direction DC about the main rotation axis MRA. In the example shown, the case 20 has a substantially cylindrical case body 21 centered on the main rotation axis MRA, and internal tooth pins 24 held on the inner surface of the case body. A plurality of pin grooves are formed in the case body 21 and arranged in the circumferential direction DC. Each pin groove houses and holds one cylindrical internal tooth pin 24 extending in an axial direction D1, which is a direction parallel to the main rotation axis MRA. Each internal tooth pin 24 constitutes one internal tooth 25.

[0031] The carrier 30 is held on the inner circumferential side of the case 20 via a pair of main bearings 12. The carrier 30 is rotatable relative to the case 20 around the main rotation axis MRA. In the illustrated example, the carrier 30 has a carrier base 31 and a carrier plate 32 that are fixed to each other. The carrier base 31 and the carrier plate 32 can be fixed to each other using fasteners such as bolts. The carrier base 31 has a disk-shaped base plate portion 31a and a plurality of pillar portions 31b protruding from the base plate portion 31a in the axial direction D1. The base plate portion 31a and the plurality of pillar portions 31b may be integrally formed. The plurality of pillar portions 31b may be provided at equal intervals in the circumferential direction DC around the main rotation axis MRA. In the illustrated specific example, three pillar portions 31b are provided.

[0032] In the illustrated example, the carrier 30 is provided with a central hole 34 and a plurality of through holes 35. The central hole 34 and the plurality of through holes 35 penetrate the carrier base 31 and the carrier plate 32, respectively. The central hole 34 is located on the main rotation axis MRA. The plurality of through holes 35 are located at equal intervals in the circumferential direction DC around the main rotation axis MRA. In the illustrated specific example, three through holes 35 are provided.

[0033] The speed reducer 100 rotates the case 20 and the carrier 30 relative to each other around the main rotation axis MRA. In the illustrated example, the speed reducer 100 has an input gear 60, a shaft member 50, and an external gear 40. The input gear 60, the shaft member 50, and the external gear 40 will be described in detail below in this order with reference to the illustrated specific example.

[0034] The input gear 60 is fixed to the shaft member 50. The input gear 60 is rotatable about a rotation axis RA parallel to the axial direction D1. The multiple input gears 60 are positioned at equal intervals in a circumferential direction DC centered on the main rotation axis MRA. In the example shown in FIG. 3, three input gears 60 are provided. The input gear 60 is a spur gear and has external teeth 61 and a connecting portion 62. The external teeth 61 and the connecting portion 62 are arranged in the circumferential direction centered on the rotation axis RA. The external teeth 61 mesh with an output gear 70 (see FIG. 3) of a driving means such as a motor. Power is transmitted to the input gear 60 from the driving means such as a motor via the external teeth 61. The connecting portion 62 is non-rotatably connected to the shaft member 50, as described below, and can transmit the rotation of the input gear 60 to the shaft member 50. The connecting portion 62 may be spline-coupled to the shaft member 50.

[0035] The shaft member 50 is rotatably held by the carrier 30. In the illustrated example, the shaft member is inserted into a through hole 35 of the carrier 30. A pair of bearings 13 is provided between the carrier 30 and the shaft member 50. Via the bearings 13, the shaft member 50 is rotatable about a rotation axis RA relative to the carrier 30. In the illustrated example, the reducer 10 has a plurality of shaft members 50 inserted into the plurality of through holes 35, respectively. The plurality of shaft members 50 are positioned at equal intervals in a circumferential direction DC centered on the main rotation axis MRA. The rotation axis RA is parallel to the main rotation axis MRA.

[0036] The shaft member 50 has a connection portion 53. The shaft member 50 and the input gear 60 are restricted from rotating relative to each other about the rotation axis RA. The shaft member 50 and the input gear 60 are connected so as not to rotate relative to each other about the rotation axis RA. The shaft member 50 is connected to a connection portion 62 of the input gear 60 at the connection portion 53 and fixed to the input gear 60. The shaft member 50 is connected to the connection portion 62 of the input gear 60 at the connection portion 53 and fixed to the input gear 60. The connection portion 53 of the shaft member 50 and the connection portion 62 of the input gear 60 may be spline-coupled. The connection portion 53 of the shaft member 50 and the connection portion 62 of the input gear 60 may be coupled using a key and key groove. Therefore, the shaft member 50 is rotatable about the rotation axis RA as the input gear 60 rotates.

[0037] In the illustrated example, the shaft member 50 has a shaft main body 51 and a pair of eccentric bodies 55 located on the shaft main body 51. The eccentric bodies 55 are cylindrical. The diameter of the eccentric bodies 55 increases from the shaft main body 51. The eccentric bodies 55 are eccentric from the rotation axis RA, which is the rotation center of the shaft member 50. The pair of eccentric bodies 55 includes a first eccentric body 55A and a second eccentric body 55B. The first eccentric body 55A and the second eccentric body 55B are eccentric from the rotation axis RA on opposite sides by the same eccentric amount. In other words, in a cross section perpendicular to the axial direction D1, the center of the first eccentric body 55A and the center of the second eccentric body 55B are located at positions symmetrical with respect to a single point on the rotation axis RA.

[0038] The shaft main body 51 has a first bearing support 52a that is inserted into the carrier plate 32 and a second bearing support 52b that is inserted into the carrier base 31. The bearing supports 52a and 52b each support a bearing 13. The pair of eccentric bodies 55A and 55B are located between the pair of bearing supports 52a and 52b in the axial direction D1. In the illustrated example, the first bearing support 52a, the first eccentric body 55A, the second eccentric body 55B, the second bearing support 52b, and the connecting portion 53 are located in this order in the axial direction D1.

[0039] The external gear 40 has external teeth 45 that mesh with internal teeth 25 provided on the inner surface of the case 20. The internal teeth 25 and the external teeth 45 have different numbers of teeth. In the example shown, the reduction gear unit 100 has a first external gear 40A and a second external gear 40B as the external gears 40. The first external gear 40A is located on a first eccentric body 55A of the multiple shaft members 50. The second external gear 40B is located on a second eccentric body 55B of the multiple shaft members 50. The first external gear 40A and the second external gear 40B are located between the base plate portion 31a of the carrier base 31 and the carrier plate 32 in the axial direction D1.

[0040] In the illustrated example, the external gear 40 has a disk-shaped central plate portion 41 and external teeth 45 arranged on the periphery of the central plate portion 41. The central plate portion 41 is provided with a central hole 42a and a post-passing hole 42b. The central hole 42a is located on the main rotation axis MRA. The central hole 42a faces the central hole 34 in the axial direction D1. In the illustrated example, multiple post-passing holes 42b are located at equal intervals in the circumferential direction around the central hole 42a. The post portions 31b of the carrier 30 pass through the post-passing holes 42b. In the illustrated specific example, three post-passing holes 42b are provided.

[0041] The central plate portion 41 is further provided with holes 43. In the illustrated example, three holes 43 are positioned at equal intervals in the circumferential direction around the central hole 42a. An eccentric body 55 is disposed within the hole 43. A bearing 15 is provided between the eccentric body 55 and the external gear 40. The first external gear 40A is supported on a first eccentric body 55A of the shaft member 50 via a first bearing 15A. The second external gear 40B is supported on a second eccentric body 55B of the shaft member 50 via a second bearing 15B.

[0042] In the illustrated example, each external gear 40 is supported by three eccentric bodies 55. The eccentric bodies 55 included in the three shaft members are aligned in phase. Therefore, as the three shaft members 50 rotate, the external gear 40 eccentrically oscillates around the main rotation axis MRA. In other words, as the three shaft members 50 rotate, the external gear 40 moves translationally along a circumferential path around the main rotation axis MRA. The first external gear 40A and the second external gear 40B operate with a half-phase shift.

[0043] Rotation is input from a driving means such as a motor to the reducer 10 having the above configuration. For example, as shown in FIG. 3, an output gear 70 of the driving means is disposed on the main rotation axis MRA and meshes with the external teeth 61 of the input gear 60. When the output gear 70 rotates, the input gear 60 rotates, and the connected shaft member 50 rotates accordingly. When the shaft member 50 rotates, the external gear 40 eccentrically oscillates. At this time, the external teeth 45 of the external gear 40 mesh with the internal teeth 25 of the case 20. Due to the difference in the number of teeth between the external teeth 45 and the internal teeth 25, the carrier 30, which supports the external gear 40 via the shaft member 50, and the case 20 rotate relatively around the main rotation axis MRA. When the case 20 is fixed, the rotation of the carrier 30 is output. When the carrier 30 is fixed, the rotation of the case 20 is output.

[0044] As mentioned in the section on prior art, the input gear receives high rotational force from the motor via the output gear at high surface pressure. Therefore, when the input gear rotates, it meshes with the output gear, generating noise. One possible method to suppress noise generation is to improve the meshing condition by improving the precision of the gear processing method and reducing the impact, but this method may not be effective depending on the assembly precision, etc.

[0045] To address this problem, in this embodiment, as will be described below, the input gear 60 is constructed with different materials in different parts. This input gear 60 can suppress noise generation. Below, the input gear 60 will be described based on several specific examples. Corresponding components, members, parts, etc. between different specific examples will be given the same reference numerals, and duplicated explanations will be omitted.

[0046] The input gear 60 described below is applicable to the above-mentioned reducer 10 described with reference to the specific example in Figures 1 to 3. On the other hand, the application of the input gear 60 is not limited to the reducer shown in Figures 1 to 3. The specific configuration of the reducer 10 shown in the drawings referred to below may not completely match the specific example shown in Figures 1 and 2, but this configuration is an example of a configuration that can be changed as appropriate.

[0047] Hereinafter, several specific examples of the input gear 60 will be described in detail with reference to FIGS.

[0048] As described above, the reducer 10 has the case 20, the carrier 30, and the reduction unit 100. The carrier 30 is rotatable relative to the case 20. The reduction unit 100 reduces the speed of the rotation input to the input gear 60 and outputs it as relative rotation between the case 20 and the carrier 30. As shown in FIGS. 4 to 7, the input gear 60 may have a first portion 63 and a second portion 64. The first portion 63 and the second portion 64 are made of different materials.

[0049] The input gear meshes with the output gear of the driving means and is subjected to high-speed rotation with high surface pressure. Therefore, it is preferable that the input gear be made of a high-strength material with a high Young's modulus. However, high-strength materials with a high Young's modulus usually have a low vibration damping rate. Therefore, the input gear is prone to generating noise.

[0050] According to this embodiment, one of the first portion 63 and the second portion 64 can be made of a high-strength material, and the other of the first portion 63 and the second portion 64 can be made of a material with a high vibration damping rate.

[0051] By making one of the first portion 63 and the second portion 64 from a high-strength material with a high Young's modulus, it is possible to ensure the strength of the connection between the input gear 60 and the output gear 70. This allows rotation to be stably input from the driving means to the reducer 10 while suppressing damage such as wear to the input gear 60. By making the other of the first portion 63 and the second portion 64 from a material with a high vibration damping rate, vibration of the input gear 60 is absorbed by the other of the first portion 63 and the second portion 64. Furthermore, by adjusting the respective proportions of the first portion 63 and the second portion 64, it is possible to control the vibration frequency of the input gear 60 and prevent resonance between the input gear 60 and other components of the reducer 10. As a result, vibration of the input gear 60 is reduced, and noise generation can be suppressed.

[0052] The input gear 60 has external teeth 61 and a connecting portion 62 that connects with the shaft member 50. In the example shown in Figure 4, a first portion 63 includes the external teeth 61, and a second portion 64 includes the connecting portion 62.

[0053] 4, the first portion 63 meshes with the output gear 70 of the drive means and receives high-speed rotation at high surface pressure. Therefore, by forming the first portion 63 from metal, steel, or a material having a higher Young's modulus than the material forming the second portion 64, it is possible to stably input rotation from the drive means to the reducer 10 while suppressing damage such as wear of the input gear 60.

[0054] On the other hand, the second portion 64 is made of a different material from the first portion 63. The rotation input to the input gear 60 from the first portion 63 is transmitted to the shaft member 50 via the second portion 64. By making the second portion 64, which is located in the transmission path, out of a material with a high vibration attenuation rate, such as rubber, resin, cast iron, or a material with a lower Young's modulus than the material making up the first portion 63, it is possible to absorb the vibration of the input gear 60 and also to prevent the vibration of the input gear 60 from being transmitted to the shaft member 50. As a result, noise can be suppressed.

[0055] In the example shown in Fig. 4, the boundary between the first portion 63 and the second portion 64 extends in the circumferential direction of the input gear 60. The input gear 60 is composed of only the first portion 63 and the second portion 64. In the example shown in Fig. 4, the first portion 63 and the second portion 64 may each be annular portions. The first portion 63 and the second portion 64 may be joined by friction welding, an adhesive, or the like.

[0056] 5, the first portion 63 includes the external teeth 61, and the second portion 64 is located between the external teeth 61 and the connecting portion 62. The first portion 63 including the external teeth 61 can achieve the same effects as the first portion 63 in the reducer 10 shown in Fig. 4. That is, by making the first portion 63 high strength, it is possible to stably input rotation from the driving means to the reducer 10 while suppressing damage such as wear of the input gear 60.

[0057] Furthermore, the second portion 64 located between the external teeth 61 and the connecting portion 62 can achieve the same effects as the second portion 64 in the reducer 10 shown in FIG. 4 . Specifically, by forming the second portion 64, located in the rotational motion transmission path, from a material with a high vibration damping rate, such as rubber, resin, cast iron, or a material with a lower Young's modulus than cast iron or the material constituting the first portion 63, the vibration of the input gear 60 can be absorbed and the transmission of the vibration of the input gear 60 to the shaft member 50 can be suppressed. As a result, noise can be suppressed. Furthermore, by adjusting the positions and volume ratios of the first portion 63 and the second portion 64, the occurrence of resonance can be suppressed. As a result, the vibration of the input gear 60 is reduced, and the occurrence of noise can be suppressed.

[0058] 5, the input gear 60 has a first portion 63, a second portion 64, and a third portion 65. The third portion 65 includes a connecting portion 62. The first portion 63, the second portion 64, and the third portion 65 are located in this order in the radial direction of the input gear 60 from the external teeth 61 toward the connecting portion 62.

[0059] The radial direction is a direction perpendicular to the rotation axis RA. The radially inner side is the side closer to the rotation axis RA in the radial direction. The radially outer side is the side farther from the rotation axis RA in the radial direction.

[0060] The material constituting the third portion 65 is different from the material constituting the first portion 63 and also different from the material constituting the second portion 64. The third portion 65 may be made of a material having a higher Young's modulus than steel or the material constituting the second portion 64. This example ensures the strength of the connection between the input gear 60 and the shaft member 50. Rotation can be stably input from the input gear 60 to the shaft member 50 while suppressing damage such as wear of the connection portion 62. Furthermore, since the first to third portions 63, 64, and 65 are made of different materials, the vibration frequency of the input gear 60 can be adjusted with a high degree of freedom. This effectively prevents resonance from occurring between the components of the reducer 10. As a result, vibration of the input gear 60 is reduced, and noise generation can be suppressed.

[0061] 5, the first portion 63, the second portion 64, and the third portion 65 may each be annular. The first portion 63 and the second portion 64 may be joined by friction welding, an adhesive, or the like. The second portion 64 and the third portion 65 may be joined by friction welding, an adhesive, or the like.

[0062] As a modified example, the third portion 65 of the reducer 10 shown in FIG. 5 may be made of the same material as the first portion 63. That is, the input gear 60 may have the first portion 63 including the connecting portion 62. In this modified example, the first portion 63, the second portion 64, and the first portion 63 are located in this order in the radial direction of the input gear 60 from the external teeth 61 toward the connecting portion 62. The first portion 63, the second portion 64, and the first portion 63 may each be annular regions. The second portion 64 is located between the first portion 63 including the external teeth 61 and the first portion 63 including the connecting portion 62. This modified example also provides the same effects as the reducer 10 shown in FIG. 5.

[0063] 6, the input gear 60 may have a third portion 65 located between the second portion 64 and the connecting portion 62. The material constituting the third portion 65 is different from the material constituting the first portion 63 and also different from the material constituting the second portion 64.

[0064] The first portion 63 including the external teeth 61 can provide the same effects as the first portion 63 in the reducer 10 shown in Figures 4 and 5. That is, by making the first portion 63 high in strength, it is possible to stably input rotation from the driving means to the reducer 10 while suppressing damage such as wear of the input gear 60. The material constituting the first portion 63 may be steel, or may be a material having a higher Young's modulus than the material constituting the second portion 64, or a material having a higher Young's modulus than the material constituting the third portion 65, or a material having a higher Young's modulus than the material constituting the second portion 64 and a higher Young's modulus than the material constituting the third portion 65.

[0065] The second portion 64 located between the external teeth 61 and the connecting portion 62 can provide the same effects as the second portion 64 in the reducer 10 shown in FIGS. 4 and 5. That is, by forming the second portion 64 located in the rotational motion transmission path from a material with a high vibration damping rate, such as rubber, resin, cast iron, or a material with a lower Young's modulus than cast iron or the material forming the first portion 63, it is possible to absorb vibrations of the input gear 60 and prevent the vibrations of the input gear 60 from being transmitted to the shaft member 50. As a result, noise can be suppressed. Furthermore, by adjusting the position and volume ratio of the second portion 64, it is possible to suppress the occurrence of resonance.

[0066] In the example shown in FIG. 6 , rotation input to the input gear 60 from the first portion 63 is transmitted to the shaft member 50 via the second portion 64 and the third portion 65. By configuring the third portion 65, which is located in the rotational motion transmission path, from a material with a high vibration damping rate, such as rubber, resin, cast iron, or a material with a lower Young's modulus than the material configuring the first portion 63, vibration of the input gear 60 can be absorbed. Furthermore, by configuring the first to third portions 63, 64, and 65 from different materials, the vibration frequency of the input gear 60 can be adjusted with a high degree of freedom. This effectively prevents resonance from occurring between the components of the reducer 10. As a result, vibration of the input gear 60 is reduced, and noise generation can be suppressed.

[0067] 6, the input gear 60 has a first portion 63, a second portion 64, a third portion 65, and a fourth portion 66. The fourth portion 66 includes a connecting portion 62. The first portion 63, the second portion 64, the third portion 65, and the fourth portion 66 are located in this order in the radial direction of the input gear 60 from the external teeth 61 toward the connecting portion 62.

[0068] The material constituting the fourth portion 66 is different from the material constituting the first portion 63, the material constituting the second portion 64, and the material constituting the third portion 65. The fourth portion 66 may be made of steel, a material having a higher Young's modulus than the material constituting the second portion 64, a material having a higher Young's modulus than the material constituting the third portion 65, or a material having a higher Young's modulus than the material constituting the second portion 64 and the material constituting the third portion 65. This example ensures the strength of the connection between the input gear 60 and the shaft member 50. Rotation can be stably input from the input gear 60 to the shaft member 50 while suppressing damage such as wear at the connection portion. Furthermore, since the first to fourth portions 63, 64, 65, and 66 are made of different materials, the vibration frequency of the input gear 60 can be adjusted with a high degree of freedom. This effectively prevents resonance between the components of the reducer 10. As a result, vibration of the input gear 60 is reduced, thereby suppressing noise generation.

[0069] 6, the first portion 63, the second portion 64, the third portion 65, and the fourth portion 66 may each be annular. The first portion 63 and the second portion 64 may be joined by friction welding, an adhesive, or the like. The second portion 64 and the third portion 65 may be joined by friction welding, an adhesive, or the like. The third portion 65 and the fourth portion 66 may be joined by friction welding, an adhesive, or the like.

[0070] As a modified example, the fourth portion 66 of the reducer 10 shown in FIG. 6 may be made of the same material as the first portion 63. That is, the input gear 60 may have a first portion including the connecting portion 62. In this modified example, the first portion 63, the second portion 64, the third portion 65, and the first portion 63 are located in this order in the radial direction of the input gear 60 from the external teeth 61 toward the connecting portion 62. The first portion 63, the second portion 64, the third portion 65, and the first portion 63 may each be annular regions. The second portion 64 and the third portion 65 are located between the first portion 63 including the external teeth 61 and the first portion 63 including the connecting portion 62. This modified example also provides the same effects as the reducer 10 shown in FIG. 5.

[0071] In the illustrated example, the first portion 63 includes the external teeth 61. The second portion 64 includes the connecting portion 62 or is located between the first portion 63 and the connecting portion 62 in the radial direction. As a first example, the Young's modulus of the material of the first portion 63 may be greater than the Young's modulus of the material of the second portion 64. As a second example, the first portion 63 may include steel, and the second portion 64 may include cast iron. As a third example, the first portion 63 may include metal, and the second portion 64 may include rubber or resin. According to the first to third examples, by selecting the materials of the first portion 63 and the second portion 64 in this manner, the strength of the first portion 63 is increased, thereby suppressing damage such as wear of the input gear 60 and enabling stable input of rotation from the driving means to the reducer 10. Furthermore, the second portion 64, which is located in the rotational motion transmission path, can absorb vibrations of the input gear 60 and suppress transmission of the vibrations of the input gear 60 to the shaft member 50. As a result, noise can be reduced. Furthermore, by adjusting the position and volume ratio of the second portion 64, it is possible to suppress the occurrence of resonance and reduce noise.

[0072] 7, the boundary 68 between the first portion 63 and the second portion 64 may include an inclined portion 68A that is inclined with respect to a circumference centered on the rotation axis RA of the input gear 60. By including the inclined portion 68A in the boundary 68, it is possible to increase the area of ​​the boundary surface between the first portion 63 and the second portion 64. According to this example, vibrations generated in the first portion 63 including the external teeth 61 are more easily transmitted to the second portion 64, which has excellent vibration damping properties, and vibrations can be efficiently damped.

[0073] In the example shown in FIG. 7 , the boundary 68 between the first portion 63 and the second portion 64 includes an inclined portion 68A and a circumferential portion 68B along a circumference centered on the rotational axis RA of the input gear 60. The boundary 68 may include the inclined portions 68A and the circumferential portions 68B alternating along the circumference centered on the rotational axis RA of the input gear 60. The boundary 68 may include multiple inclined portions 68A. The boundary 68 may include multiple circumferential portions 68B. The multiple inclined portions 68A may be positioned at equal intervals along the circumference centered on the rotational axis RA of the input gear 60. The multiple circumferential portions 68B may be positioned at equal intervals along the circumference centered on the rotational axis RA of the input gear 60. In the example shown, the inclined portion 68A protrudes radially outward from the circumferential portion 68B. Unlike the illustrated example, the inclined portion 68A may protrude radially inward from the circumferential portion 68B, or may protrude radially both outward and inward from the circumferential portion 68B.

[0074] In the example shown in FIGS. 4-7 , the first portion 63, the second portion 64, the third portion 65, and the fourth portion 66 included in the input gear 60 are annular, but this is not limiting. As indicated by the two-dot chain line in FIG. 4 , any one or more of the first portion 63, the second portion 64, the third portion 65, and the fourth portion 66 may have a shape other than annular. Any one or more of the first portion 63, the second portion 64, the third portion 65, and the fourth portion 66 may have a circular, elliptical, triangular, rectangular, pentagonal, hexagonal, or polygonal shape. Any one or more of the first portion 63, the second portion 64, the third portion 65, and the fourth portion 66 having a shape other than annular may be provided in plural. Any one or more of the first portion 63, the second portion 64, the third portion 65, and the fourth portion 66 having a shape other than annular may be provided in plural at equal intervals along a circumference centered on the rotation axis RA of the input gear 60. In the example shown by the two-dot chain line in Figure 4, multiple third portions 65 having shapes other than annular are provided. In this example, the material constituting the third portions 65 may be a material having a lower Young's modulus than the material constituting the first portion 63, or may be a material having a lower Young's modulus than the material constituting the second portion 64. The material constituting the third portions 65 may be a material having a higher Young's modulus than the material constituting the second portion 64. In this example, the third portions 65 may be press-fitted into the second portion 64, or may be joined with an adhesive or the like.

[0075] As another embodiment, as shown by the two-dot chain line in FIG. 4 and also shown in FIG. 8, a hole 67 may be provided in the input gear 60. The hole 67 may be an air gap. The hole 67 can release vibration, thereby reducing vibration generated in the input gear 60. This can reduce noise. Furthermore, the frequency of vibration generated in the input gear 60 can be adjusted while reducing the weight of the gear, and resonance of other members of the reducer 10 can be suppressed.

[0076] In the example shown in FIG. 8 , the reducer 10 includes a case 20, a carrier 30 rotatable relative to the case 20, and a speed reducer unit 100 having an input gear 60 with a hole 67 formed therein and receiving rotation as input. The speed reducer unit 100 reduces the speed of the rotation input to the input gear 60 and outputs the rotation as relative rotation between the case 20 and the carrier 30. The input gear 60 is formed with the hole 67. In the example shown in FIG. 8 , the input gear 60 has the hole 67, which makes it possible to suppress noise generation in the reducer 10, as described above. In the example shown in FIG. 8 , the input gear 60 with the hole 67 may be made of a certain material, and noise generation can be suppressed.

[0077] On the other hand, as shown by the two-dot chain line in FIG. 4, an input gear 60 including a first portion 63 and a second portion 64 made of different materials may have a hole 67.

[0078] 8, the hole 67 is located between the external teeth 61 and the connecting portion 62. The hole 67 located in the transmission path can suppress the vibration of the input gear 60 from being transmitted to the shaft member 50. As a result, noise can be suppressed.

[0079] The hole 67 may be a through-hole that penetrates the input gear 60 in the axial direction D1. The hole 67 may be a recess (bottomed hole) that opens in the axial direction D1. The shape of the hole 67 provided in the input gear 60 is not particularly limited. The hole 67 may be circular, elliptical, triangular, rectangular, pentagonal, hexagonal, or polygonal. The number of holes 67 provided in the input gear 60 is not particularly limited and may be one, two, three, four, five, six, or seven or more. When there are multiple holes 67, the sizes of the multiple holes 67 may be the same or different. Furthermore, when there are multiple holes 67, the multiple holes 67 may be located on the same circumference centered on the rotation axis RA. In other words, the multiple holes 67 may be located at the same radial position. The multiple holes 67 may be located on different circumferences centered on the rotation axis RA. That is, the multiple holes 67 may be located at different radial positions. The multiple holes 67 provided in the input gear 60 may have a constant hole pitch in the circumferential direction centered on the rotation axis RA. That is, the multiple holes 67 may be positioned at equal intervals along the circumference centered on the rotation axis RA of the input gear 60. Also, the multiple holes 67 do not need to have a constant hole pitch in the circumferential direction centered on the rotation axis RA.

[0080] 4, the input gear 60 includes third portions 65 and holes 67. The third portions 65 and the holes 67 are alternately arranged in the circumferential direction around the rotation axis RA.

[0081] Although the present embodiment has been described with reference to a number of specific examples, the present embodiment is not limited to these specific examples, and the present embodiment can be implemented with various other specific examples, and various omissions, substitutions, changes, and additions can be made without departing from the spirit of the present invention.

[0082] For example, in the above-described specific example, the reducer 10 is an eccentric oscillating reducer. In this example, the reduction unit 100 includes an input gear 60, a shaft member 50 to which the input gear 60 is fixed and which is rotatably held by a carrier, and an external gear 40 which has external teeth 45 that mesh with the internal teeth 25 of the case 20 and is eccentrically oscillated by the shaft member 50. A plurality of shaft members 50 are rotatably held by one carrier 30.

[0083] However, without being limited to this specific example, the reducer 10 may have only two shaft members 50. In this modification, the reducer 10 may have two input gears 60 fixed to each shaft member 50. In another modification, the reducer may have only one shaft member 50 located on the main rotation axis MRA. In this modification, the reducer 10 may have a single input gear 60.

[0084] Furthermore, the reducer 10 is not limited to an eccentric oscillating reducer. The reducer 10 may be a planetary gear reducer. In an example where the reducer 10 is a planetary gear reducer, the input gear 60 may constitute a planetary gear. The reduction unit 100 may be an input gear as a planetary gear rotatably held by the carrier 30.

[0085] Among the embodiments disclosed in this specification, those that are comprised of multiple objects may be integrated, and conversely, those that are comprised of a single object may be separated into multiple objects. Regardless of whether they are integrated, it is sufficient that they are configured to achieve the object of the invention. [Explanation of symbols]

[0086] 10: Reducer 20: Case 30: Career 50: Shaft member 60: Input gear 61: External teeth 62: Connection 63: Part 1 64:Second part 65: 3rd part 67: hole 68: Realm 68A: Inclined section 100: Deceleration section

Claims

1. Case and Career and a reduction section that has an input gear including a first portion and a second portion made of different materials, and that reduces the speed of rotation input to the input gear and outputs it as relative rotation of one of the case and the carrier with respect to the other.

2. the speed reducer portion has a shaft member rotatably held by the carrier, the input gear has external teeth and a connection portion that connects to the shaft member, The reducer according to claim 1 , wherein the first portion includes external teeth and the second portion includes a connecting portion.

3. the speed reducer portion has a shaft member rotatably held by the carrier, the input gear has external teeth and a connection portion that connects to the shaft member, The reducer according to claim 1 , wherein the first portion includes external teeth, and the second portion is located between the external teeth and the connecting portion.

4. the input gear has the first portion including the connection portion, The reducer according to claim 3 , wherein the second portion is located between the first portion including the external teeth and the first portion including the connection portion.

5. the input gear has a third portion including the connection portion, The reducer according to claim 3 , wherein the material constituting the third portion is different from the material constituting the first portion and different from the material constituting the second portion.

6. the input gear has a third portion located between the second portion and the connection portion, The reducer according to claim 3 , wherein the material constituting the third portion is different from the material constituting the first portion and different from the material constituting the second portion.

7. The reducer according to any one of claims 2 to 6, wherein a Young's modulus of a material constituting the first portion is greater than a Young's modulus of a material constituting the second portion.

8. The speed reducer of any one of claims 2 to 6, wherein the first portion comprises steel and the second portion comprises cast iron.

9. The reducer according to any one of claims 2 to 6, wherein the first portion includes a metal, and the second portion includes a rubber or a resin.

10. The reducer according to any one of claims 2 to 6, wherein the boundary between the first portion and the second portion includes an inclined portion inclined with respect to a circumference centered on the rotation axis of the input gear.

11. The reducer according to claim 1 , wherein the input gear is provided with a hole.

12. Case and Career and a reduction gear section that has an input gear having a hole and that receives rotation as an input, and that reduces the speed of the rotation input to the input gear and outputs the rotation as a relative rotation of one of the case and the carrier relative to the other.

13. the speed reducer portion has a shaft member rotatably held by the carrier, the input gear has external teeth and a connection portion that connects to the shaft member, The reducer according to claim 11 or 12, wherein the hole is located between the external teeth and the connecting portion.

14. The reducer according to claim 11 or 12, wherein a plurality of the holes are provided.

15. The speed reducer is a shaft member to which the input gear is fixed and which is rotatably held by the carrier; The reducer according to claim 1 , further comprising: an external gear having external teeth that mesh with the internal teeth of the case, the external gear being eccentrically oscillated by the shaft member.

16. The reducer according to claim 1 , wherein the input gear functions as a planetary gear.

Images