Transmission

Abstract

A transmission (100) is provided with a cylindrical rotary housing (15) that accommodates a planetary gear mechanism (40) and that rotates by transmitting output rotation that has been shifted, the planetary gear mechanism (40) being provided with: a plurality of annular second planetary gears (53) that mesh with both a second sun gear (51) and an internal gear (42); and a plurality of second planet carriers (54) supporting the second planet gears (53), the second planet carriers (54) being provided with a plurality of second plates (80) covering at least a part of the second planet gears (53), fixed to the second planet carriers (54), for preventing the second planet gears (53) from falling off from the second planet carriers (54), the second plates (80) being configured so as to cover at least a part of the second planet gears (53), and the second plates (80) being configured so as to cover at least a part of the second planet gears (53) and fixed to the second planet carriers (54). Each of the first and second planetary gear carriers (54) is fixed so as to straddle the two or more second planetary gear carriers (54).

Description

Technical Field

[0001] This invention relates to a transmission. Background Technology

[0002] Japanese Patent Application Publication No. JP2017-116055A discloses a transmission comprising: a fixed housing housing a hydraulic motor; a transmission mechanism for changing the output rotation of the hydraulic motor shaft; a rotating housing housing the transmission mechanism, through which the output rotation after speed change is transmitted to the rotating housing for rotation; and a cover for closing the opening of the rotating housing. The transmission described in JP2017-116055A is a planetary gear mechanism and includes: a sun gear disposed on the shaft of the hydraulic motor; an internal gear disposed on the inner wall of the rotating housing; and multiple planetary gears meshing with both the sun gear and the internal gears. A plate for preventing detachment and a fixing member for fixing the plate to the body are provided on the body portion supporting the planetary gears. By covering a portion of the planetary gears with the plate, the planetary gears are prevented from detaching. Summary of the Invention

[0003] In the transmission described in Japanese Patent Application Publication JP2017-116055A, the plate is formed into a ring shape and is formed by stamping the base material using a stamping press or the like. Therefore, more end material is wasted during plate formation, potentially increasing the manufacturing cost of the transmission.

[0004] The purpose of this invention is to reduce the manufacturing cost of transmissions.

[0005] According to one aspect of the invention, a transmission includes: a shaft to which the output rotation of a drive source is transmitted; a planetary gear mechanism connected to the shaft and for changing the speed of the output rotation of the drive source; a cylindrical rotating housing housing the planetary gear mechanism, which rotates by transmitting the changed output rotation to the cylindrical rotating housing, the planetary gear mechanism including: a sun gear to which the power of the drive source is transmitted via the shaft; an inner gear formed on the inner circumferential surface of the rotating housing; a plurality of annular planetary gears having hollow portions and meshing with both the sun gear and the inner gear; a plurality of support portions respectively inserted into the hollow portions of the plurality of planetary gears and supporting the planetary gears, a plate provided on the support portion, the plate covering at least a portion of the planetary gear and fixed to the support portion, and used to prevent the planetary gear from falling off the support portion, the plate being composed of a plurality of plates and fixed in such a way that each spans two or more of the support portions. Attached Figure Description

[0006] Figure 1This is a cross-sectional view of a motor with a transmission, including the transmission according to an embodiment of the present invention. Figure 2 This is a top view of the second sun gear, the second planetary gear, and the second plate. Figure 3 For along Figure 2 A cross-sectional view along line III-III. Figure 4 This diagram illustrates the process of removing the die when forming a second sheet through stamping. Figure 5 This is a top view of the planetary gear mechanism according to a modified example 2 of the present invention, and... Figure 2 The corresponding representation is made. Figure 6 This is a top view of the planetary gear mechanism according to Variation 3 of the present invention, and... Figure 2 The corresponding representation is made. Figure 7 This diagram illustrates the die-taking process when the second plate, as described in Modified Example 3 of the present invention, is formed by stamping through stamping. Figure 8 This diagram illustrates the die-taking process when the second plate, according to a comparative example of an embodiment of the present invention, is formed by stamping through stamping. Figure 9 This is a top view of the planetary gear mechanism according to Variation 4 of the present invention, and... Figure 2 The corresponding representation is made. Figure 10 This is a top view of the planetary gear mechanism according to Variation 4 of the present invention, and... Figure 2 The corresponding representation is made. Figure 11 This is a top view of the planetary gear mechanism according to Variation 5 of the present invention, and... Figure 2 The corresponding representation is made. Detailed Implementation

[0007] Hereinafter, with reference to the accompanying drawings, the transmission 100 according to this embodiment of the present invention and the motor 101 with transmission as a drive device having the transmission 100 will be described.

[0008] A motor 101 with a transmission is installed, for example, in the axle of a tracked work machine such as a hydraulic excavator, and drives the tracks. Figure 1 As shown, the motor 101 with a gearbox includes a hydraulic motor 20 as a drive source and a gearbox 100 connected to the motor shaft (not shown) of the hydraulic motor 20 and reducing the output rotation of the motor shaft.

[0009] The transmission 100 includes: a planetary gear mechanism 40 as a transmission mechanism that changes the output rotation of the hydraulic motor 20; a fixed housing 10 that houses the hydraulic motor 20; a cylindrical rotating housing 15 that houses the planetary gear mechanism 40, through which the output rotation after speed change is transmitted to the cylindrical rotating housing 15 for rotation; and a cover 60 that is disposed on the inner periphery of the open end 15a of the rotating housing 15 and closes the open end 15a of the rotating housing 15. The specific structure of the planetary gear mechanism 40 will be described later. The housing 1 of the transmission 100 is formed by the fixed housing 10, the rotating housing 15, and the cover 60.

[0010] The rotating housing 15 rotates relative to the fixed housing 10. The open end 15a of the rotating housing 15 is on the side opposite to the hydraulic motor 20 relative to the planetary gear mechanism 40. Figure 1 The opening is on the right side of the rotating housing 15. A sprocket (not shown) is connected to the outer circumferential surface of the rotating housing 15. The vehicle moves by rotating the rotating housing 15 and the sprocket together, causing the track (not shown) that meshes with the sprocket to circulate.

[0011] The fixed housing 10 and the rotating housing 15 are disposed inside the path of the track circulation. The rotating housing 15 is supported by bearings 3 to rotate freely relative to the fixed housing 10 connected to the vehicle body 102, and rotates around its central axis.

[0012] The fixed housing 10 has: a body portion 11; and a fixed flange portion 12, which is formed in such a way as to protrude from the outer peripheral surface of the body portion 11 and is mounted on the vehicle body 102.

[0013] The cover 60 is formed in the shape of a disc and is mounted on the inner circumferential surface of the open end 15a of the rotating housing 15. A plug 61 is provided in the center of the cover 60. As will be described later, the plug 61 bears the thrust load generated in the planetary gear mechanism 40 via the first plate 70.

[0014] The gear chamber 4, which houses the planetary gear mechanism 40, is divided by the inner surface of the rotating outer shell 15, the outer surface of the main body 11 of the fixed outer shell 10, and the inner surface of the cover 60. Lubricating oil, which lubricates the planetary gear mechanism 40, is sealed inside the gear chamber 4.

[0015] A rotating flange portion 16 is formed on the rotating housing 15, protruding annularly from the outer peripheral surface. The sprocket is fastened to the rotating flange portion 16 by a plurality of bolts (not shown) and rotates together with the rotating housing 15.

[0016] A floating seal 5 is provided between the fixed housing 10 and the rotating housing 15. The floating seal 5 seals the transmission 100 so that the working oil inside the transmission 100 does not leak to the outside when the rotating housing 15 is rotating, and prevents foreign objects from entering the transmission 100 from the outside.

[0017] Furthermore, a labyrinth seal 6 is formed between the fixed housing 10 and the rotating housing 15. The labyrinth seal 6 prevents foreign objects such as mud from entering the outside of the floating seal 5. The labyrinth seal 6 is formed by the gap between the opposing end faces of the fixed housing 10 and the rotating housing 15.

[0018] The hydraulic motor 20 is housed inside the body portion 11 of the fixed housing 10. The hydraulic motor 20 is, for example, a swashplate piston motor that is driven to rotate by the supply and discharge of working oil (working fluid). Alternatively, the motor can be other than a hydraulic motor; for example, an electric motor can be used. Although the hydraulic motor 20 can adopt a known structure, therefore, in Figure 1 The diagram is simplified and detailed descriptions are omitted in this specification.

[0019] The transmission 100 includes a drive shaft 31, which is coaxially connected to the motor shaft of the hydraulic motor 20 and transmits the output rotation of the motor shaft. A planetary gear mechanism 40 is connected to the drive shaft 31 and reduces the output rotation of the hydraulic motor 20's motor shaft, transmitting it to the rotating housing 15. The drive shaft 31 and the motor shaft of the hydraulic motor 20 are joined, for example, by a spline coupling. The drive shaft 31 and the motor shaft of the hydraulic motor 20 may also be integrally formed. Furthermore, since the rotating housing 15 and the drive shaft 31 are coaxially mounted, the axial direction of the rotating housing 15 and the drive shaft 31 will be referred to as "axial direction" below, and the radial direction of the rotating housing 15 and the drive shaft 31 will be referred to as "radial direction".

[0020] The planetary gear mechanism 40 includes: a first sun gear 41 to which power from the hydraulic motor 20 is transmitted via a drive shaft 31; an inner gear 42 formed on the inner circumferential surface of the rotating housing 15; a plurality of annular first planetary gears 43 meshing with both the first sun gear 41 and the inner gear 42; a plurality of first planetary carriers 44 inserted into the hollow portions of the plurality of first planetary gears 43 and supporting the first planetary gears 43; a second sun gear 51 meshing with each of the plurality of first planetary carriers 44; a plurality of annular second planetary gears 53 meshing with both the second sun gear 51 and the inner gear 42; and a plurality of second planetary carriers 54 inserted into the hollow portions of the plurality of second planetary gears 53 and supporting the second planetary gears 53. In this embodiment, the second sun gear 51, the second planetary gear 53, and the second planetary gear carrier 54 correspond to the "sun gear," "planetary gear," and "support" in the technical solution.

[0021] Multiple first planetary gear carriers 44 are arranged circumferentially separate from each other, and multiple second planetary gear carriers 54 are also arranged circumferentially separate from each other. The second planetary gear carriers 54 are mounted on the end face of the cover 60 side of the main body 11 of the fixed housing 10 by means of fixing members (not shown). The first stage gear carrier of the planetary gear mechanism 40 is formed by the first sun gear 41, the first planetary gear 43, and the first planetary gear carrier 44, and the second stage gear carrier of the planetary gear mechanism 40 is formed by the second sun gear 51, the second planetary gear 53, and the second planetary gear carrier 54. The first stage gear carrier is positioned closer to the cover 60 side than the second stage gear carrier. The end faces of the first planetary gear 43 and the first planetary gear carrier 44 on the cover 60 side are on the same plane, and the end faces of the second planetary gear 53 and the second planetary gear carrier 54 on the cover 60 side are on the same plane. In this embodiment, four second planetary gears 53 are provided (see reference). Figure 2 The second planetary gear 53 is supported on the second planetary gear carrier 54 by an annular needle bearing 57 and an annular internal bearing 58 disposed inside the needle bearing 57.

[0022] When the motor shaft of the hydraulic motor 20 is driven to rotate, the drive shaft 31 connected to the motor shaft rotates along with the rotation of the motor shaft. The output rotation of the drive shaft 31 acts on the internal gear 42 via the first sun gear 41 and the first planetary gear 43, and the second sun gear 51 and the second planetary gear 53 of the second stage, and is transmitted to the rotating housing 15. In the transmission 100 of this embodiment, the first planetary gear 43 and the internal gear 42, and the second planetary gear 53 and the internal gear 42 are formed to mesh obliquely relative to the axial direction. Therefore, a thrust load (load along the axial direction) is generated in the planetary gear mechanism 40 due to the reaction force of the force acting on the internal gear 42 from the first planetary gear 43 and the second planetary gear 53. As a result, a force acts on the first planetary gear 43 in a manner that disengages from the first planetary gear carrier 44, and a force acts on the second planetary gear 53 in a manner that disengages from the second planetary gear carrier 54.

[0023] Therefore, in the planetary gear mechanism 40, a first plate 70 covering a portion of the first planetary gear 43 and used to prevent the first planetary gear 43 from detaching from the first planetary gear carrier 44 is fixed to the first planetary gear carrier 44 by a first threaded member 46. Additionally, a second plate 80 covering a portion of the second planetary gear 53 and used to prevent the second planetary gear 53 from detaching from the second planetary gear carrier 54 is fixed to the second planetary gear carrier 54 by a second threaded member 56. In this embodiment, the second plate 80 corresponds to the "plate" in the inventive technical solution.

[0024] First, let's explain the first board 70.

[0025] The first plate 70 is formed in a circular plate shape and is formed by stamping a single plate. The first plate 70 is positioned across the drive shaft 31, the first sun gear 41, the first planetary gear carrier 44, and the end faces of each of the first planetary gears 43 opposite to the cover 60. The first plate 70 is configured to cover the entire hollow portion of the first planetary gear 43 and a portion of the first planetary gear 43. Specifically, in Figure 1 In the cross-sectional view shown, the first plate 70 covers the entire first planetary gear 43 on the side closest to the drive shaft 31 compared to the hollow portion, and a portion on the opposite side of the drive shaft 31 separated by the hollow portion.

[0026] Since the first plate 70 is fixed to the first planetary gear carrier 44, the axial movement of the first planetary gear 43 is restricted by the first plate 70, preventing the first planetary gear 43 from falling off the first planetary gear carrier 44. Furthermore, the thrust load generated in the planetary gear mechanism 40 acts on the plug 61 provided on the cover 60 via the larger area of ​​the first plate 70. The thrust load of the planetary gear mechanism 40 borne by the plug 61 is evenly distributed by the first plate 70; therefore, the first plate 70 and the plug 61 make surface contact in a non-unilateral manner. This prevents uneven wear on the first plate 70 and the plug 61.

[0027] Next, we will explain the second board 80.

[0028] Figure 2 This is a top view of the second sun gear 51, the second planetary gear 53, and the second plate 80. Figure 2 And the following Figure 5 , 6 In sections 9-11, the internal gear 42 and the second threaded component 56 are omitted. For example... Figure 1 , Figure 2 As shown, the second plate 80 is disposed on the end face of the cover 60 side in the second planetary gear carrier 54 and the second planetary gear 53. Figure 2 As shown, the second plate 80 is composed of multiple plates and is fixed in such a way that each plate spans two adjacent second planetary gear carriers 54 in the circumferential direction. The second plates 80 are arranged continuously to surround the second sun gear 51 when viewed along the axial direction of the drive shaft 31. Specifically, in the transmission 100 of this embodiment, two second plates 80 of the same shape are provided. By making each second plate 80 the same shape (common parts), the number of types of parts managed in the inventory remains unchanged. Hereinafter, for ease of explanation, the components of the second plate 80 will also be described... Figure 2 The plate on the right is called the second plate 80a, and the plate on the left is called the second plate 80b. Additionally, the second planetary gear 53... Figure 2 The upper plate is called the second planetary gear 53a, the right plate is called the second planetary gear 53b, the lower plate is called the second planetary gear 53c, and the left plate is called the second planetary gear 53d.

[0029] The second plates 80a and 80b are formed by stamping a single plate. The second plates 80a and 80b have V-shaped body portions 81a and 81b, and one end portion 82a and 82b is bent to form a stepped portion 83a and 83b in the thickness direction of the plate.

[0030] The widths of the straight sections of the body portions 81a and 81b are formed to be the same. Specifically, the inner peripheral surface 86a on the side of the second sun gear 51 and the outer peripheral surface 87a on the opposite side of the second sun gear 51 of the body portion 81a each have straight sections 91a and 92a, which are formed parallel to each other (of the same shape). The inner peripheral surface 86b on the side of the second sun gear 51 and the outer peripheral surface 87b on the opposite side of the second sun gear 51 of the body portion 81b each have straight sections 91b and 92b, which are formed parallel to each other (of the same shape). The body portions 81a and 81b are formed by cutting open the V-shaped top, i.e., the base portions 88a and 88b. Figure 3 As shown, the stepped portions 83a and 83b are higher than the main body portions 81a and 81b and are formed in a stepped shape. The stepped portions 83a and 83b have the same thickness as the main body portions 81a and 81b. With the second plates 80a and 80b fixed to the second planetary gear carrier 54, a space is formed between the stepped portions 83a and 83b and the second planetary gear carrier 54. No stepped portions are formed at the other ends 84a and 84b of the second plates 80a and 80b. Figure 2 As shown, the center of the body portion 81a of the second plate 80a is disposed on the second planetary gear 53b, one end portion 82a (step portion 83a) is disposed on the second planetary gear 53a, and the other end portion 84a is disposed on the second planetary gear 53c. The center of the body portion 81b of the second plate 80b is disposed on the second planetary gear 53d, one end portion 82b (step portion 83b) is disposed on the second planetary gear 53c, and the other end portion 84b is disposed on the second planetary gear 53a.

[0031] like Figure 2 , Figure 3 As shown, the other end 84b of the second plate 80b enters the space below the stepped portion 83a of the second plate 80a, and the other end 84a of the second plate 80a enters the space below the stepped portion 83b of the second plate 80b, so that the ends of the second plates 80a and 80b are arranged to overlap each other. In this way, the second sun gear 51 is enclosed in a quadrilateral by the second plates 80a and 80b, and each of the second plates 80a and 80b provides anti-detachment protection for three second planetary gears 53. In this state, adjacent second plates 80a and 80b are continuous, and the second planetary gear 53 sides of the second plates 80a and 80b become flat. In other words, the body portion 81a of the second plate 80a, the other end 84b of the second plate 80b, the body portion 81b of the second plate 80b, and the other end 84a of the second plate 80a are located on the same plane. On the second plates 80a and 80b, a plurality of fastening holes 55 are formed for fastening the second threaded component 56.

[0032] Figure 4 This diagram illustrates the die-taking process when the second plate 80 is formed by stamping. In this embodiment, the multiple second plates 80 have the same shape. Furthermore, the inner and outer shapes of each second plate 80 are formed to partially correspond to each other. Specifically, as described above, the inner peripheral surface 86 (straight portion 91) and outer peripheral surface 87 (straight portion 92) of the second plate 80 in the straight portion of the body portion 81 are formed parallel to each other (of the same shape). Therefore, as... Figure 4 As shown, multiple second plates 80 are formed in a manner in which their inner peripheral surfaces 86 and outer peripheral surfaces 87 are in contact with each other. In this way, the end material discarded during the formation of the second plates 80 becomes the notch portion of the base portion 88 of the body portion 81, the portion between the ends 82 of one side, the portion between the ends 84 of the other side, and the portion of the fastening hole 55, thereby minimizing its use.

[0033] Thus, in the transmission 100 of this embodiment, a plurality of second plates 80 are provided on the second planetary gear carrier 54 to prevent the second planetary gear 53 from falling off. Therefore, as... Figure 8 As shown, compared to the case where a single annular second plate 580 is provided, each of the second plates 80 can be made smaller, and less end material is wasted during the formation of the second plate 80. Specifically, in a single annular second plate 580, more end material is generated in the hollow portion A of the second plate 580 and in the space B between the second plates 580. However, in the transmission 100 of this embodiment, each of the second plates 80 is smaller, thus reducing the space required to generate end material. This reduces the manufacturing cost of the transmission 100. Furthermore, since each of the second plates 80 is smaller, not only is the storage space in warehouses or the like reduced, but the number of plates that can be processed at once during heat treatment and surface treatment of the second plates 80 can also be increased, further reducing the manufacturing cost of the transmission 100.

[0034] Furthermore, in the transmission 100, the inner shape (inner peripheral surface 86) and outer shape (outer peripheral surface 87) of each of the plurality of second plates 80 are formed into partially corresponding shapes. In other words, the inner peripheral surface 86 and outer peripheral surface 87 of the second plate 80 each have straight portions 91 and 92, and a portion of the straight portions 91 and 92 are formed into corresponding shapes (identical shapes). Therefore, when the plurality of second plates 80 are stamped by stamping, the plurality of second plates 80 can be formed in an arranged manner. Thus, the amount of end material can be reduced. In other words, "the inner peripheral surface 86 and outer peripheral surface 87 of each of the plurality of second plates 80 are formed into partially corresponding shapes" means, as... Figure 4As shown, when a sheet is stamped to form multiple second plates 80, the inner peripheral surfaces 86 (straight portions 91) and outer peripheral surfaces 87 (straight portions 92) of adjacent second plates 80 are formed in contact and arranged. By forming multiple second plates 80 in contact and arranged, the number of cuts during stamping is reduced, thus improving the processability of the second plates 80. Furthermore, if multiple second plates 80 can be arranged continuously, the second plates 80 do not necessarily need to be formed in contact with each other.

[0035] Furthermore, in the transmission 100, a step portion 83 is formed in the thickness direction at one end 82 of one of the plurality of second plates 80. Therefore, even if the ends of the second plates 80 overlap (end 82 and end 84), the step portion 83 can be used to make the side of the second planetary gear 53 flat. This prevents one-sided contact between the second plate 80 and the second planetary gear 53, needle roller bearing 57, internal bearing 58, etc., and improves the durability of the transmission 100.

[0036] Furthermore, during the operation of the transmission 100, the multiple second plates 80 bear rotational loads (rotational torques) from the contacting second planetary gear 53 and second threaded member 56. This raises the possibility that the second plates 80 may tilt, leading to one-sided contact with the second planetary gear 53, needle roller bearing 57, internal bearing 58, etc. However, in the transmission 100 of this embodiment, the multiple second plates 80 are fixed at least in two locations. Therefore, it is difficult for the second plates 80 to tilt. Moreover, the multiple second plates 80 are arranged in a ring and continuously around the second sun gear 51, further reducing the likelihood of tilting. This prevents one-sided contact of the second plates 80 and improves durability. Additionally, compared to the case where a single second plate 80 is fixed in one location, the rigidity of the second plates 80 is higher, thus allowing the multiple second plates 80 to be thinner.

[0037] According to the above implementation method, the following effects are achieved.

[0038] In the transmission 100, a plurality of second plates 80 are provided on the second planetary gear carrier 54 to prevent the second planetary gear 53 from falling off. This allows each second plate 80 to be smaller and reduces the amount of end material wasted during the formation of the second plates 80. Consequently, the manufacturing cost of the transmission 100 can be reduced.

[0039] Next, variations of the above-described embodiments will be described. The following variations are also within the scope of the present invention, and the structures described in the following different variations can be combined with each other.

[0040] <Modification 1> In the above embodiment, regarding the plurality of second plates 80, one end 82 is bent to form a stepped portion 83 that is higher than the main body portion 81, and the other end 84 of another second plate 80 enters the space below the stepped portion 83, thereby making the second planetary gear 53 side flat. Not limited to this, regarding the plurality of second plates 80, one end 82 may not be bent, and a stepped portion 83 formed by cutting the second planetary gear 53 side in the plate thickness direction may be formed on one end 82, and a stepped portion formed by cutting the opposite side to the second planetary gear 53 may be formed on the other end 84, with the stepped portions meshing with each other. Even with this structure, the end material can be reduced. Furthermore, by having the other end 84 enter the space between the stepped portion 83 and the second planetary gear carrier 54, the ends 82 and 84 are arranged overlapping each other, thus making the second planetary gear 53 side flat and improving the durability of the transmission 100.

[0041] <Modification 2> In the above embodiment, a plurality of second plates 80 have a stepped portion 83 formed at one end 82, and the respective ends 82, 84 are provided overlapping each other. This is not a limitation; for example... Figure 5 As shown, the multiple second plates 180 may not have the stepped portion 83 formed, but are instead continuously arranged by their respective ends 182, 184 abutting against each other. In this structure, one end 182a of the second plate 180a abuts against the other end 184b of the second plate 180b, and the other end 184a of the second plate 180a and one end 182b of the second plate 180b are respectively arranged to face each other. Furthermore, the fastening hole 55 corresponding to the second planetary gear 53a is provided across one end 182a of the second plate 180a and the other end 184b of the second plate 180b, and the fastening hole 55 corresponding to the second planetary gear 53c is provided across one end 184a of the second plate 180a and the other end 182b of the second plate 180b. The second plates 180a and 180b are connected by fastening with the fastening hole 55 via the second threaded member 56. Even with this structure, the number of end pieces can be reduced, and the multiple second plates 180 are less likely to tilt, thus improving the durability of the multiple second plates 180. In addition, protrusions and recesses for receiving the protrusions can also be provided at the mating portions of the second plates 180a and 180b.

[0042] <Modification 3> In the above embodiment, the plurality of second plates 80 are formed in a V-shape. However, this is not a limitation; for example… Figure 6As shown, multiple second plates 280 can also be formed in an arc shape. Specifically, the second plates 280a and 280b have arc-shaped body portions 281a and 281b. With the second plates 280 mounted on the second planetary gear carrier 54, the body portions 281a and 281b are formed within a 180° range centered on the axis of the drive shaft 31, without contacting the second sun gear 51. The inner circumferential surfaces 86a and 86b and the outer circumferential surfaces 87a and 87b are formed with corresponding shapes (specifically, concentric circles centered on the drive shaft 31). In other words, the inner circumferential surface 86a on the side of the second sun gear 51 and the outer circumferential surface 87a on the opposite side of the second sun gear 51 of the second plate 280a each have curved portions 93a and 94a, which are formed concentric circles (of the same shape). The inner peripheral surface 86b on the side of the second sun gear 51 of the second plate 280b and the outer peripheral surface 87b on the opposite side of the second sun gear 51 have curved portions 93b and 94b, respectively, which are formed concentric circles (of the same shape). In this structure, similar to the modified example 2 described above, one end 282a of the second plate 280a and the other end 284b of the second plate 280b are joined together, and the other end 284a of the second plate 280a and the end 282b of one plate 280b are provided in a ground-to-ground manner. A protrusion 288 and a recess 289 for receiving the protrusion 288 are respectively provided at the joining portion of the second plates 280a and 280b, thereby facilitating the positioning of the second plates 280a and 280b and improving the assemblability of the transmission 100. Alternatively, the protrusion 288 and the recess 289 may not be provided. Furthermore, similar to the above embodiment, the ends of the second plates 280a and 280b may be arranged to overlap each other. When the ends of the second plates 280 overlap each other, fastening holes 55 are formed at both ends of the second plates 280. When mounted on the second planetary gear carrier 54, the angle between the centers of these fastening holes 55, centered on the axis of the drive shaft 31, is 180°. Even with this structure, the amount of end material can be reduced, and the multiple second plates 280 are less prone to tilting, improving the durability of the multiple second plates 280.

[0043] In addition, such as Figure 6 As shown, preferably, the inner diameter D1 of the second plates 280a and 280b is formed to be more than twice the radial width D2. In this structure, as... Figure 7 As shown, when multiple plates 280 are stamped by stamping, plates 280 can be formed with the ends 282 and 284 of the other two plates 280 entering the space C inside the plate 280. Therefore, the space C can be used to form other second plates 280. Thus, as Figure 8As shown, compared with the case of setting a ring-shaped second plate 580, the space that becomes the end material, such as the hollow part A of the second plate 580 and the space B between the second plates 580, can be reduced, and the end material can be reduced.

[0044] <Modification 4> In the above embodiment, the plurality of second plates 80 are formed in a V-shape. However, this is not a limitation; for example… Figure 9 As shown, the multiple second plates 380 can also be formed as short strips. The widths of the second plates 380a and 380b are formed to be the same, and the inner peripheral surfaces 86a and 86b on the side of the second sun gear 51 and the outer peripheral surfaces 87a and 87b on the opposite side of the second sun gear 51 are formed to have corresponding shapes (specifically, they are parallel to each other). In other words, the inner circumferential surface 86a on the side of the second sun gear 51 of the second plate 380a and the outer circumferential surface 87a on the opposite side of the second sun gear 51 each have straight portions 91a and 92a, which are formed parallel to each other (with the same shape). The inner circumferential surface 86b on the side of the second sun gear 51 of the second plate 380b and the outer circumferential surface 87b on the opposite side of the second sun gear 51 each have straight portions 91b and 92b, which are formed parallel to each other (with the same shape). In this modified example, the entire inner circumferential surface 86a and the outer circumferential surface 87a of the second plate 380a are straight portions 91a and 92a, and the entire inner circumferential surface 86b and the outer circumferential surface 87b of the second plate 380b are straight portions 91b and 92b. In this case, a plurality of second plates 380a and 380b are respectively arranged to span between adjacent second planetary gears 53 in the circumferential direction. Specifically, the second plate 380a is arranged across the space between the second planetary gear 53a and the second planetary gear 53b, and the second plate 380b is arranged across the space between the second planetary gear 53c and the second planetary gear 53d. Thus, multiple second plates 380 do not necessarily have to be arranged continuously around the second sun gear 51.

[0045] In addition, such as Figure 10 As shown, second plates 380a and 380d can also be provided, and the second plates 380a to 380d are provided in an overlapping manner. Specifically, the second plate 380c is provided across the space between the second planetary gear 53b and the second planetary gear 53c, and the second plate 380d is provided across the space between the second planetary gear 53a and the second planetary gear 53d. Furthermore, similar to the above embodiment, a stepped portion can be formed at the end of at least one of the second plates 380a to 380d, and the respective ends are provided in an overlapping manner. In this structure, the second plates 380 are continuously provided adjacent to each other in the circumferential direction. Even with this structure, the amount of end material can be reduced.

[0046] <Modification 5> In the above embodiment, four second planetary gears 53 are provided, and two second plates 80 are provided to prevent the second planetary gears 53 from falling off, respectively. However, the number of second planetary gears 53 and second plates 80 is not limited to those described above. For example... Figure 11 As shown, three second planetary gears 53 can also be provided, and three second plates 480 are provided to prevent the two second planetary gears 53 from falling off. Each of the multiple second plates 480 has an arc-shaped body portion 481, with its inner circumferential surface 86 and outer circumferential surface 87 formed into corresponding shapes (specifically, the same radius of curvature). In other words, the inner circumferential surface 86 on the side of the second sun gear 51 and the outer circumferential surface 87 on the opposite side of the second plate 480 each have curved portions 93 and 94, which are formed to be parallel to each other (of the same shape). Furthermore, the curved portions 93 and 94 may or may not be perfectly circular. With the second plate 480 mounted on the second planetary gear carrier 54, the body portion 481 is formed within a 120° range centered on the axis of the drive shaft 31. Specifically, fastening holes 55 are formed at both ends of the second plate 480. With the second plate 480 mounted on the second planetary gear carrier 54, the angle between the centers of these fastening holes 55, centered on the axis of the drive shaft 31, is 120°. Thus, when multiple second plates are each formed in an arc shape, the length of the arc-shaped body portion corresponds to the distance between adjacent second planetary gear carriers 54 in the circumferential direction. In this structure, similar to the embodiment described above, the ends of adjacent second plates 480 in the circumferential direction (ends 482 and 484 where the stepped portions 483 are formed) are arranged to overlap each other. Even with this structure, it is possible to... Figure 4 By forming multiple second plates 480 in a manner that their inner circumferential surfaces 86 and outer circumferential surfaces 87 are in contact with each other, the number of end pieces can be reduced. In addition, the multiple second plates 480 are less prone to tilting, thus improving their durability.

[0047] <Modification 6> In the above embodiment, the inner shape (inner peripheral surface 86) and outer shape (outer peripheral surface 87) of each of the plurality of second plates 80 are formed as partially corresponding shapes. However, this is not a limitation; the plurality of second plates 80 may also be formed as having completely corresponding inner and outer shapes. Furthermore, the inner and outer shapes of each of the plurality of second plates 80 do not necessarily have to be formed as partially corresponding shapes.

[0048] <Modification 7> In the above embodiment, a plurality of second plates 80 are fixed to the second planetary gear carrier 54 by a second threaded member 56. Not limited thereto, the plurality of second plates 80 may also be fixed to the second planetary gear carrier 54, for example, by a retaining ring. In this structure, a portion of the second planetary gear carrier 54 is formed by inserting into a fastening hole 55, and the plurality of second plates 80 are held in place by the retaining ring so as not to detach from the second planetary gear carrier 54.

[0049] The structure, function, and effects of the embodiments of the present invention are summarized and explained below.

[0050] The transmission 100 includes: a drive shaft 31 serving as a shaft, to which the output rotation of a hydraulic motor 20, serving as a drive source, is transmitted; a planetary gear mechanism 40 connected to the drive shaft 31, which changes the speed of the output rotation of the hydraulic motor 20; and a cylindrical rotating housing 15 housing the planetary gear mechanism 40, to which the changed output rotation is transmitted and rotated. The planetary gear mechanism 40 includes: a second sun gear 51 serving as a sun gear, to which the power of the hydraulic motor 20 is transmitted via the drive shaft 31; an internal gear 42 formed on the inner circumferential surface of the rotating housing 15; and a plurality of annular second planetary gears 53 serving as planetary gears, each having a hollow portion and connected to the second sun gear. Gear 51 and internal gear 42 mesh with each other; multiple second planetary gear carriers 54, which serve as support parts, are respectively inserted into the hollow portions of multiple second planetary gears 53 and support the second planetary gears 53. Second plates 80, 180, 280, 380, and 480, which serve as plates, are provided on the second planetary gear carriers 54. The second plates 80, 180, 280, 380, and 480 cover at least a portion of the second planetary gears 53 and are fixed to the second planetary gear carriers 54 to prevent the second planetary gears 53 from falling off the second planetary gear carriers 54. Multiple second plates 80, 180, 280, 380, and 480 are formed and fixed in such a way that they span two or more second planetary gear carriers 54 respectively.

[0051] In this structure, multiple second plates 80, 180, 280, 380, and 480 are provided on the second planetary gear carrier 54 to prevent the planetary gears from falling off. This allows the individual second plates 80, 180, 280, 380, and 480 to be smaller, and reduces the amount of waste end material generated during the formation of the second plates 80, 180, 280, 380, and 480. Consequently, the manufacturing cost of the transmission 100 can be reduced.

[0052] Furthermore, in the transmission 100, the inner shape (inner peripheral surface 86) on the side of the second sun gear 51 of the plurality of second plates 80, 180, 380, 480 and the outer shape (outer peripheral surface 87) on the opposite side of the second sun gear 51 respectively have straight portions 91, 92 or curved portions 93, 94, and at least a portion of the straight portions 91, 92 or the curved portions 93, 94 are formed into corresponding shapes.

[0053] In this structure, when multiple second plates 80, 180, 380, and 480 are stamped by stamping, multiple second plates 80, 180, 380, and 480 can be arranged to form, thus reducing the amount of end material.

[0054] In addition, in the transmission 100, multiple second plates 280 are respectively mounted on the second planetary gear carrier 54, and are formed in an arc shape with the axis of the drive shaft 31 as the center in a manner that does not abut against the second sun gear 51, with the inner diameter D1 being more than twice the radial width D2.

[0055] In this structure, when multiple second plates 280 are stamped by stamping, the ends 282 and 284 of the other two second plates 280 can enter the space C inside the second plate 280, thus reducing the amount of end material.

[0056] In addition, in the transmission 100, multiple plates 380 are formed into short strips.

[0057] In this structure, when multiple second plates 380 are stamped by stamping, multiple second plates 380 can be formed in an arranged manner, thus reducing the amount of end material.

[0058] In addition, in the transmission 100, multiple second plates 80, 180, 280, 380, and 480 are continuously arranged such that they surround the second sun gear 51 when viewed axially from the drive shaft 31.

[0059] In this structure, the multiple second plates 80, 180, 280, 380, and 480 are difficult to tilt, which improves the durability of the multiple second plates 80, 180, 280, 380, and 480.

[0060] In addition, in the transmission 100, a plurality of second plates 80, 480 each have a stepped portion 83, 483 formed at least at one end 82, 482 in the thickness direction, and enter the space between the stepped portion 83, 483 and the second planetary gear carrier 54 through the other end 84, 484, so that the respective ends 82, 84, 482, 484 are arranged to overlap each other.

[0061] In this structure, even if the ends 82, 84, 482, and 484 of the second plates 80 and 480 overlap, the steps 83 and 483 can be used to make the side of the second planetary gear 53 flat. This prevents the second plates 80 and 480 from contacting the second planetary gear 53 on one side, thus improving the durability of the transmission 100.

[0062] In addition, in the transmission 100, the ends 182, 184, 282, 284 of the plurality of second plates 180, 280 are arranged in a manner that connects with each other.

[0063] In this structure, the multiple second plates 180 and 280 are difficult to tilt, which improves the durability of the multiple second plates 180 and 280.

[0064] The embodiments of the present invention have been described above. However, the above embodiments are merely some examples of the application of the present invention and are not intended to limit the technical scope of the present invention to the specific structures of the above embodiments.

[0065] This application claims priority based on Japanese Patent Application No. 2023-102358 filed with the Japan Patent Office on June 22, 2023, the entire contents of which are incorporated herein by reference.

Claims

1. A transmission, comprising: The shaft is the axis to which the output rotation of the drive source is transmitted. A planetary gear mechanism, which is connected to the shaft, and performs speed change on the output rotation of the drive source; A cylindrical rotating housing houses the planetary gear mechanism, and the output rotation after speed change is transmitted to the cylindrical rotating housing for rotation. The planetary gear mechanism has the following features: Sun gear, the power of the drive source is transmitted to the sun gear via the shaft; An internal gear is formed on the inner circumferential surface of the rotating housing; Multiple ring-shaped planetary gears, each having a hollow portion, mesh with both the sun gear and the internal gear; Multiple support portions are respectively inserted into the hollow portions of the multiple planetary gears and support the planetary gears. A plate is provided on the support portion, the plate covering at least a portion of the planetary gear and being fixed to the support portion, and serving to prevent the planetary gear from falling off the support portion. The plate is composed of multiple parts and is fixed in such a way that it spans two or more of the support portions respectively.

2. The transmission as claimed in claim 1, wherein, The inner shape of the sun gear side and the outer shape of the opposite side of the sun gear of the plurality of plates have straight or curved portions, and at least a portion of the straight portions or the curved portions are formed into corresponding shapes.

3. The transmission as claimed in claim 1, wherein, With each plate installed on the support, the plates are formed in an arc shape with the axis of the shaft as the center, without contacting the sun gear, and the inner diameter is more than twice the radial width.

4. The transmission as claimed in claim 1, wherein, The plates are each formed into short strips.

5. The transmission as claimed in any one of claims 1 to 4, wherein, The plates are arranged continuously to surround the sun gear when viewed axially from the shaft.

6. The transmission as claimed in claim 5, wherein, The plurality of plates each have a stepped portion formed at least at one end in the thickness direction, and enter the space between the stepped portion and the support portion through the other end, so that the ends are arranged to overlap each other.

7. The transmission as claimed in claim 5, wherein, The ends of the plurality of plates are arranged in a mating manner with each other.

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