Transmission

Abstract

To reduce a size of a transmission.SOLUTION: A transmission 100 comprises a cylindrical rotating housing 15 for accommodating a planetary gear mechanism 40, and rotating by being transmitted with gear-changed output rotation. The planetary gear mechanism 40 has: a plurality of cylindrical planetary gears 43 which are engaged with both a sun gear 41 and an inner gear 42; and planetary carriers 44 as a plurality of support parts inserted into hollow parts 43a of the plurality of planetary gears 43, and supporting the planetary gears 43. The planetary carrier 44 is provided with: a plate 45 for covering at least a part of the planetary gears 43, and preventing the come-off of the planetary gears 43 from the planetary carriers 44; and a screw member 46 for fixing the plate 45 to the planetary carriers 44. The planetary carrier 44 has accommodation holes 47 for accommodating at least a part of a head part 46a of the screw member 46 and a part of the plate 45.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Patent Document 1 discloses a transmission including a fixed housing that accommodates a hydraulic motor, a speed change mechanism that changes the speed of the output rotation of the shaft of the hydraulic motor, a rotating housing that accommodates the speed change mechanism and rotates by receiving the changed output rotation, and a cover that closes the open end of the rotating housing. The speed change mechanism described in Patent Document 1 is a planetary gear mechanism, and includes a sun gear provided on the shaft of the hydraulic motor, an inner gear provided on the inner wall of the rotating housing, and a plurality of planetary gears that mesh with both the sun gear and the inner gear. A main body that supports the planetary gear is provided with a plate for preventing it from coming off and a fixing member that fixes the plate to the main body, and the planetary gear is prevented from coming off by covering a part of the planetary gear with the plate. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-116055 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the transmission described in Patent Document 1, a plate and a fixing member are provided on the main body to prevent the planetary gear from coming off, which increases the axial dimension of the transmission and makes the transmission larger.

[0005] The present invention has been made in consideration of the above problems, and has an object to reduce the size of a transmission. [Means for solving the problem]

[0006] The present invention is a transmission comprising: a shaft to which the output rotation of a drive source is transmitted; a planetary gear mechanism connected to the shaft and changing the speed of the output rotation of the drive source; and a cylindrical rotating housing that houses the planetary gear mechanism and rotates by the changed output rotation transmitted thereto. The planetary gear mechanism comprises a sun gear to which power from the drive source is transmitted via the shaft, an inner gear formed on the inner surface of the rotating housing, a plurality of annular planetary gears having a hollow portion and meshing with both the sun gear and the inner gear, and a plurality of support portions that are inserted into the hollow portions of the plurality of planetary gears to support the planetary gears. The support portion is provided with a plate that covers at least a portion of the planetary gear and prevents the planetary gear from coming off the support portion, and a screw member that fixes the plate to the support portion, and the support portion has an accommodating hole that accommodates at least a portion of the head of the screw member and a portion of the plate.

[0007] In this invention, at least a portion of the head of the plate and the screw member that prevents the planetary gear from coming loose is received in the receiving hole of the support part, which reduces the amount by which the plate and the screw member protrude in the axial direction from the support part, thereby making it possible to reduce the axial dimension of the transmission.

[0008] In addition, the present invention is characterized in that the plate has an anti-slip portion that covers at least a portion of the planetary gear and a retaining portion that is accommodated in the accommodating hole and is held by being sandwiched between the inner surface of the accommodating hole and the head of the screw member, and the anti-slip portion and the retaining portion are bent by plastic deformation.

[0009] In this invention, the retaining portion and the holding portion are bent by plastic deformation, which increases the rigidity of the retaining portion, allowing the plate to be made thinner.

[0010] In the present invention, the plate is provided in a state in which the holding portion is bent and elastically deformed.

[0011] In this invention, the elastic force of the plate prevents the screw member from loosening.

[0012] The present invention is also characterized in that the accommodating hole has a first accommodating portion in which at least a portion of the head of the screw member is accommodated, a threaded portion in which a threaded portion of the screw member is screwed into, and a second accommodating portion provided between the first accommodating portion and the threaded portion, formed with a diameter larger than the inner diameter of the thread, so that the threaded portion does not screw into the second accommodating portion.

[0013] In the present invention, the axial force of the screw member is prevented from decreasing. Effect of the Invention

[0014] According to the present invention, the transmission can be made smaller in size. [Brief description of the drawings]

[0015] [Figure 1] 1 is a cross-sectional view of a transmission-equipped motor including a transmission according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of A shown in FIG. [Diagram 3] FIG. 4 is a plan view of the second sun gear, the second planetary gear, and the second plate. [Figure 4] 3 is an enlarged cross-sectional view showing a state before a second plate is attached to a second planetary carrier, and corresponds to FIG. 2. [Diagram 5] FIG. 4 is a plan view of a planetary gear mechanism according to a modified example of the present invention, and corresponds to FIG. 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, a transmission 100 according to an embodiment of the present invention and a transmission-equipped motor 101 as a drive device including the same will be described with reference to the drawings.

[0017] The transmission-equipped motor 101 is provided on the axle of a crawler-type working machine such as a hydraulic excavator to drive the crawler belt. As shown in Fig. 1, the transmission-equipped motor 101 includes a hydraulic motor 20 as a drive source, and a transmission 100 connected to a motor shaft (not shown) of the hydraulic motor 20 to reduce the output rotation of the motor shaft.

[0018] The transmission 100 includes a planetary gear mechanism 40 as a speed change mechanism that changes the output rotation of the hydraulic motor 20, a fixed housing 10 that accommodates the hydraulic motor 20, a cylindrical rotating housing 15 that accommodates the planetary gear mechanism 40 and rotates by receiving the changed output rotation, and a cover 60 that is provided on the inner periphery of an open end 15a of the rotating housing 15 and closes the open end 15a of the rotating housing 15. A specific configuration of the planetary gear mechanism 40 will be described later. The fixed housing 10, the rotating housing 15, and the cover 60 form a housing 1 of the transmission 100.

[0019] The rotating housing 15 rotates relative to the fixed housing 10. An open end 15a of the rotating housing 15 opens to the planetary gear mechanism 40 on the opposite side to the hydraulic motor 20 (the right side in FIG. 1). A sprocket (not shown) is connected to the outer circumferential surface of the rotating housing 15. As the rotating housing 15 and the sprocket rotate together, a crawler belt (not shown) that meshes with the sprocket circulates, causing the vehicle to travel.

[0020] The fixed housing 10 and the rotating housing 15 are disposed inside the path along which the crawler belt circulates. The rotating housing 15 is rotatably supported via bearings 3 with respect to the fixed housing 10, which is connected to the vehicle body 102, and rotates about its central axis.

[0021] The fixed housing 10 has a main body portion 11 and a fixed flange portion 12 formed to protrude from the outer circumferential surface of the main body portion 11 and attached to a vehicle body 102 .

[0022] The cover 60 is formed in a disk shape, and is attached to 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. The plug 61 receives a thrust load generated in the planetary gear mechanism 40 via the first plate 45, as will be described later.

[0023] A gear chamber 4 that houses the planetary gear mechanism 40 is defined by the inner surface of the rotating housing 15, the outer surface of the main body 11 of the fixed housing 10, and the inner surface of the cover 60. The gear chamber 4 is filled with lubricating oil as a lubricant capable of lubricating the planetary gear mechanism 40.

[0024] A rotating flange portion 16 that protrudes annularly from the outer circumferential surface of the rotating housing 15 is formed. 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.

[0025] A floating seal 5 is provided between the fixed housing 10 and the rotating housing 15. The floating seal 5 seals the hydraulic oil in the transmission 100 so that it does not leak out to the outside when the rotating housing 15 rotates, and also prevents foreign matter from entering the transmission 100 from the outside.

[0026] In addition, a labyrinth seal 6 is formed between the fixed housing 10 and the rotating housing 15 to prevent foreign matter such as mud from entering from the outside to 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.

[0027] The hydraulic motor 20 is provided inside the main body 11 of the fixed housing 10. The hydraulic motor 20 is, for example, a swash plate type piston motor that is rotationally driven by the supply and discharge of hydraulic oil (hydraulic fluid). The motor may be a type other than a hydraulic motor, and for example, an electric motor may be used. The hydraulic motor 20 can have a known configuration, and therefore is illustrated in a simplified manner in FIG. 1, and detailed description thereof will be omitted in this specification.

[0028] The transmission 100 includes a drive shaft 31 that is coaxially connected to the motor shaft of the hydraulic motor 20 and serves as a shaft to which the output rotation of the motor shaft is transmitted. The planetary gear mechanism 40 is connected to the drive shaft 31 and transmits the output rotation of the motor shaft of the hydraulic motor 20 to the rotating housing 15 after reducing the speed. The drive shaft 31 and the motor shaft of the hydraulic motor 20 are connected by, for example, a spline connection. The drive shaft 31 and the motor shaft of the hydraulic motor 20 may be integrally configured. Since the rotating housing 15 and the drive shaft 31 are provided coaxially, hereinafter, the axial direction of the rotating housing 15 and the drive shaft 31 will also be simply referred to as the "axial direction" and the radial direction of the rotating housing 15 and the drive shaft 31 will also be simply referred to as the "radial direction".

[0029] The planetary gear mechanism 40 includes a first sun gear 41 to which the power of the hydraulic motor 20 is transmitted via the 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 hollow portions 43a of the first planetary gears 43 to support the first planetary gears 43, a second sun gear 51 meshing with each of the 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 hollow portions 53a of the second planetary gears 53 to support the second planetary gears 53. In this embodiment, the second planetary gears 53 and the second planetary carriers 54 correspond to the "planetary gears" and "supporting portions" in the claims.

[0030] The first planetary carriers 44 are spaced apart from one another in the circumferential direction, and the second planetary carriers 54 are also spaced apart from one another in the circumferential direction. The second planetary carrier 54 is provided on the end face of the main body 11 of the fixed housing 10 on the cover 60 side via a fixing member (not shown in the figure) or the like. The first sun gear 41, the first planetary gear 43, and the first planetary carrier 44 form a first stage carrier of the planetary gear mechanism 40, and the second sun gear 51, the second planetary gear 53, and the second planetary carrier 54 form a second stage carrier of the planetary gear mechanism 40. The first stage carrier is provided closer to the cover 60 side than the second stage carrier. The end faces of the first planetary gear 43 and the first planetary carrier 44 on the cover 60 side are located on the same plane, and the end faces of the second planetary gear 53 and the second planetary carrier 54 on the cover 60 side are located on the same plane. The first planetary carrier 44 has a first accommodating hole 47 in which a first screw member 46 described later is accommodated, and the second planetary carrier 54 has a second accommodating hole 57 in which a second screw member 56 and a second plate 55 described later are accommodated.

[0031] When the motor shaft of the hydraulic motor 20 is driven to rotate, the drive shaft 31 connected to the motor shaft rotates in accordance with the rotation of the motor shaft. The output rotation of the drive shaft 31 acts on the inner gear 42 through the first sun gear 41 and the first planetary gear 43, and the second-stage second sun gear 51 and the second planetary gear 53, and is transmitted to the rotating housing 15. In the transmission 100 of this embodiment, the first planetary gear 43 and the inner gear 42, and the second planetary gear 53 and the inner gear 42 are formed by being obliquely meshed with each other with respect to the axial direction. Therefore, a thrust load (a load along the axial direction) is generated in the planetary gear mechanism 40 due to a reaction force of the force acting on the inner gear 42 from the first planetary gear 43 and the second planetary gear 53. Therefore, a force acts on the first planetary gear 43 to disengage from the first planetary carrier 44 , and a force acts on the second planetary gear 53 to disengage from the second planetary carrier 54 .

[0032] Therefore, in the planetary gear mechanism 40, a first plate 45 that covers the first planetary gear 43 and prevents the first planetary gear 43 from coming off the first planetary carrier 44, and a first screw member 46 that fixes the first plate 45 to the first planetary carrier 44 are provided on the first planetary carrier 44. In addition, a second plate 55 that covers the second planetary gear 53 and prevents the second planetary gear 53 from coming off the second planetary carrier 54, and a second screw member 56 that fixes the second plate 55 to the second planetary carrier 54 are provided on the second planetary carrier 54. In this embodiment, the second plate 55 and the second screw member 56 correspond to the "plate" and "screw member" in the claims.

[0033] The first plate 45 is formed in a disk shape and is provided across the drive shaft 31, the first sun gear 41, the first planetary carrier 44, and the end faces of each first planetary gear 43 that face the cover 60. The first plate 45 is provided so as to cover the entire hollow portion 43a of the first planetary gear 43 and to cover a part of the first planetary gear 43. Specifically, in the cross-sectional view shown in Fig. 2, the first plate 45 covers the entire first planetary gear 43 on the drive shaft 31 side of the hollow portion 43a, and a part of the side opposite the drive shaft 31 with the hollow portion 43a interposed therebetween.

[0034] The first plate 45 is fixed to the first planetary carrier 44 by receiving the shaft portion 46b of the first screw member 46 in the first receiving hole 47 and screwing the threaded portion of the first screw member 46 with the threaded portion on the inner circumferential surface of the first receiving hole 47. In this embodiment, only the shaft portion 46b of the first screw member 46 is received in the first receiving hole 47, and the head portion 46a of the first screw member 46 is not received in the first receiving hole 47 and is provided in a state of protruding in the axial direction from the first planetary carrier 44. Here, the head portion 46a of the first screw member 46 is a portion that holds the first plate 45 between the first planetary carrier 44 and the head portion 46a. In addition, the shaft portion 46b of the first screw member 46 is a portion of the first screw member 46 that exerts a fastening force on the first planetary carrier 44. The same applies to the second screw member 56.

[0035] By fixing the first plate 45 to the first planetary carrier 44 in this manner, the axial movement of the first planetary gear 43 is restricted by the first plate 45, and the first planetary gear 43 is prevented from coming off the first planetary carrier 44. Furthermore, the thrust load generated in the planetary gear mechanism 40 acts on the plug 61 provided in the cover 60 via the single first plate 45 having a wide area. Since the thrust load of the planetary gear mechanism 40 received by the plug 61 is equalized by the first plate 45, the first plate 45 and the plug 61 come into surface contact with each other without making a one-sided contact. This prevents uneven wear of the first plate 45 and the plug 61.

[0036] 2 is an enlarged cross-sectional view of the vicinity of A shown in FIG. 1, and FIG. 3 is a plan view of the second sun gear 51, the second planetary gear 53, and the second plate 55. In FIG. 3, the inner gear 42 is omitted. As shown in FIG. 1 to FIG. 3, the second plate 55 is provided on the end faces of the second planetary carrier 54 and each second planetary gear 53 on the cover 60 side, and is formed in an annular shape (see FIG. 3). The second plate 55 is provided so as to cover the entire hollow portion 53a of the second planetary gear 53 and to cover a part of the second planetary gear 53. Specifically, the second plate 55 covers a part of the second planetary gear 53 on the drive shaft 31 side of the hollow portion 53a, and a part on the opposite side of the drive shaft 31 across the hollow portion 53a, in the cross-sectional views shown in FIG. 1 and FIG. 2.

[0037] 2, the second plate 55 has a retaining portion 55a that covers a part of the second planetary gear 53, a retaining portion 55b that is accommodated in the second accommodating hole 57 of the second planetary carrier 54 and is sandwiched and held between the inner circumferential surface of the second accommodating hole 57 and the head 56a of the second screw member 56, an insertion portion 55c through which the second screw member 56 is inserted, and a boundary portion 55d between the retaining portion 55a and the retaining portion 55b. The retaining portion 55a and the retaining portion 55b of the second plate 55 are bent by plastic deformation. In other words, the boundary portion 55d is provided in the second plate 55 by bending by plastic deformation.

[0038] The second plate 55 is fixed to the second planetary carrier 54 with the shaft portion 56b of the second screw member 56 accommodated in the second accommodation hole 57. The second accommodation hole 57 has a first accommodation portion 57a ​​in which a part of the head portion 56a of the second screw member 56 is accommodated, a screw-engaging portion 57b in which a thread is formed to screw with the screw portion 56c of the second screw member 56, and a second accommodation portion 57c provided between the first accommodation portion 57a ​​and the screw-engaging portion 57b and formed to have a larger diameter than the inner diameter of the thread of the screw-engaging portion 57b (the dimension B shown in FIG. 4) and into which the screw portion 56c is not screwed. The inner diameter of the thread of the screw-engaging portion 57b is specifically the diameter of the hole formed by the thread of the screw-engaging portion 57b. The first accommodation portion 57a ​​is formed in a tapered shape so that the diameter becomes smaller as it approaches the second accommodation portion 57c. The screw-engaging portion 57b and the second accommodation portion 57c are formed coaxially. The second accommodating portion 57c is formed to have a larger diameter than the inner diameter of the apex of the thread of the screw-engaging portion 57b, and no threaded portion is formed therein. The second plate 55 is fixed to the second planetary carrier 54 by having the shaft portion 56b of the second screw member 56 accommodated in the second accommodating hole 57 and having the screw portion 56c of the second screw member 56 and the screw-engaging portion 57b screwed together. In this embodiment, the shaft portion 56b of the second screw member 56 is accommodated in the second accommodating hole 57, and a part of the head portion 56a of the second screw member 56 is also accommodated in the second accommodating hole 57 (first accommodating portion 57a).

[0039] In this manner, by fixing the second plate 55 to the second planetary carrier 54, the axial movement of the second planetary gear 53 is restricted by the second plate 55, and the second planetary gear 53 is prevented from coming off from the second planetary carrier 54. In the transmission 100 of this embodiment, as described above, a part of the second plate 55 that prevents the second planetary gear 53 from coming off and a part of the head 56a of the second screw member 56 are accommodated in the second accommodation hole 57 of the second planetary carrier 54. This reduces the amount by which the second plate 55 and the second screw member 56 protrude in the axial direction from the second planetary carrier 54. Therefore, the axial dimension of the transmission 100 is reduced, and the transmission 100 can be made smaller.

[0040] In the transmission 100 of this embodiment, the second accommodating hole 57 has a second accommodating portion 57c between the first accommodating portion 57a ​​and the screwing portion 57b, where the threaded portion 56c is not screwed. In other words, the threaded portion 56c of the second screw member 56 has a region 56d facing the second accommodating portion 57c that is not screwed. Therefore, even if a force acts on the retaining portion 55a of the second plate 55 from the second planetary gear 53 and a force that would cause the second screw member 56 to come off acts on the head 56a, the region 56d (the region that is not screwed) elastically deforms to absorb the force. Therefore, a decrease in the axial force of the second screw member 56 is prevented.

[0041] Furthermore, in the transmission 100 of this embodiment, as described above, the amount by which the second plate 55 and the second screw member 56 protrude in the axial direction from the second planetary carrier 54 is small. Therefore, the thickness of the first planetary carrier 44 on the second plate 55 side can be increased, and the strength of the first planetary carrier 44 can be improved.

[0042] Furthermore, in the transmission 100, the retaining portion 55a and the retaining portion 55b are bent by plastic deformation. In other words, the boundary portion 55d between the retaining portion 55a and the retaining portion 55b is formed by bending by plastic deformation. This increases the rigidity of the retaining portion 55a, allowing the second plate 55 to be made thinner. This allows the axial dimension of the transmission 100 to be reduced.

[0043] The head 56a of the second screw member 56 may be entirely housed in the second housing hole 57 (first housing portion 57a) of the second planetary carrier 54. The second plate 55 may cover the entire second planetary gear 53.

[0044] According to the present embodiment described above, the following advantageous effects are obtained.

[0045] In the transmission 100, the second plate 55, which prevents the second planetary gear 53 from coming loose, and a portion of the head 56a of the second screw member 56 are accommodated in the second accommodating hole 57 of the second planetary carrier 54, so that the amount by which the second plate 55 and the second screw member 56 protrude axially from the second planetary carrier 54 is reduced, allowing the transmission 100 to be made smaller.

[0046] Next, modified examples of the above embodiment will be described. The following modified examples are also within the scope of the present invention, and it is also possible to combine the configurations described in the following different modified examples.

[0047] <Variation 1> In the above embodiment, at least a part of the head 56a of the second screw member 56 and a part of the second plate 55 are accommodated in the second accommodation hole 57 of the second planetary carrier 54, which is the second stage carrier, and the head 46a of the first screw member 46 and the first plate 45 are not accommodated in the first accommodation hole 47 of the first planetary carrier 44, which is the first stage carrier. However, the present invention is not limited to this, and may be configured such that the first plate 45 has a retaining portion, a holding portion, and an insertion portion similar to those of the second plate 55, the first accommodation hole 47 has a first accommodation portion, a screwing portion, and a second accommodation portion similar to those of the second accommodation hole 57, and at least a part of the head 46a of the first screw member 46 and a part of the first plate 45 are accommodated in the first accommodation hole 47 of the first planetary carrier 44. In other words, the configuration in which the planetary carrier has an accommodation hole in which at least a part of the head of the screw member and a part of the plate are accommodated is provided in at least one of the first stage carrier and the second stage carrier of the planetary gear mechanism 40.

[0048] <Variation 2> In the above embodiment, the second plate 55 is provided in a state where the boundary portion 55d between the retaining portion 55a and the holding portion 55b is bent. The second plate 55 may be provided in a state where the holding portion 55b is bent and elastically deformed. In other words, the second plate 55 may be provided in a state where the boundary portion 55d between the retaining portion 55a and the holding portion 55b is bent and elastically deformed. Before being fixed by the second screw member 56, the second plate 55 is formed in a flat shape, or the obtuse angle formed by the retaining portion 55a and the holding portion 55b is larger than the obtuse angle formed by the surface of the second planetary carrier 54 and the first housing portion 57a ​​of the second housing hole 57. Specifically, as shown in FIG. 4, before being held by the second screw member 56, the holding portion 55b of the second plate 55 does not contact the inner peripheral surface of the first housing portion 57a. In other words, the holding portion 55b is formed to have an angle difference of angle θ with respect to the inner peripheral surface of the first housing portion 57a. From this state, when the second screw member 56 is inserted into the insertion portion 55c and the threaded portion 56c of the second screw member 56 is screwed into the screwing portion 57b, as shown in Fig. 2, the head 56a of the second screw member 56 elastically deforms the retaining portion 55b, the retaining portion 55b is bent relative to the retaining portion 55a, and the retaining portion 55b comes into contact with the inner circumferential surface of the first accommodating portion 57a. In this configuration, the elastic force of the second plate 55 acts on the head 56a of the second screw member 56, preventing the second screw member 56 from loosening. Furthermore, the second plate 55 that prevents the second planetary gear 53 from falling off has a function of a washer that prevents the second screw member 56 from loosening, so that the number of parts of the transmission 100 can be reduced.

[0049] <Modification 3> In the above embodiment, the second plate 55 is formed in an annular shape. This makes it easier to process the second plate 55. However, the shape of the second plate 55 is not limited to the above as long as it can prevent the second planetary gear 53 from coming off. For example, as shown in FIG. 5, the second plate 55 may be formed in a strip shape. In this case, two sets of the second plate 55 are provided between the second planetary carriers 54 adjacent in the circumferential direction. In this configuration, the strip-shaped second plate 55 can be cut out and processed without waste from a single plate that is a base material. Also, the second plate 55 may be provided individually for each second planetary carrier 54.

[0050] The configuration, operation, and effects of the embodiment of the present invention will be described below.

[0051] The transmission 100 includes a drive shaft 31 as a shaft to which the output rotation of a hydraulic motor 20 as a drive source is transmitted, a planetary gear mechanism 40 connected to the drive shaft 31 and changing the speed of the output rotation of the hydraulic motor 20, and a cylindrical rotating housing 15 that houses the planetary gear mechanism 40 and rotates by the changed output rotation transmitted thereto. The planetary gear mechanism 40 includes sun gears 41, 51 to which the power of the hydraulic motor 20 is transmitted via the drive shaft 31, an inner gear 42 formed on the inner circumferential surface of the rotating housing 15, a plurality of annular planetary gears 43, 53 having hollow portions 43a, 53a and meshing with both the sun gears 41, 51 and the inner gear 42, and a plurality of planetary gears 43, 53. The planetary gears 43, 53 each have a plurality of support parts, each of which is inserted into a hollow part 43a, 53a of the planetary gear 43, 53 to support the planetary gear 43, 53. The planetary carrier 44, 54 is provided with a plate 45, 55 which covers at least a portion of the planetary gear 43, 53 and prevents the planetary gear 43, 53 from coming off the planetary carrier 44, 54, and a screw member 46, 56 which fixes the plate 45, 55 to the planetary carrier 44, 54. The planetary carrier 44, 54 has an accommodating hole 47, 57 which accommodates at least a portion of the head 46a, 56a of the screw member 46, 56 and a portion of the plate 45, 55.

[0052] In this configuration, at least a portion of the plates 45, 55 and the heads 46a, 56a of the screw members 46, 56 that prevent the planetary gears 43, 53 from coming off are housed in the housing holes 47, 57 of the planetary carriers 44, 54. This reduces the amount by which the plates 45, 55 and the screw members 46, 56 protrude in the axial direction from the planetary carriers 44, 54. This allows the axial dimension of the transmission 100 to be reduced.

[0053] Furthermore, in the transmission 100, the plates 45, 55 have an anti-slip portion 55a that covers at least a portion of the planetary gears 43, 53, and a retaining portion 55b that is accommodated in the accommodating holes 47, 57 and is held by being sandwiched between the inner surface of the accommodating holes 47, 57 and the heads 46a, 56a of the screw members 46, 56, and the anti-slip portion 55a and the retaining portion 55b are bent by plastic deformation.

[0054] In this configuration, the retaining portion 55a and the holding portion 55b are bent by plastic deformation, which increases the rigidity of the retaining portion 55a, allowing the plates 45, 55 to be made thinner.

[0055] Furthermore, in the transmission 100, the plates 45, 55 are provided in a state in which the holding portions 55b are bent and elastically deformed.

[0056] In this configuration, the elastic force of the plates 45, 55 prevents the screw members 46, 56 from loosening.

[0057] In addition, in the transmission 100, the accommodating holes 47, 57 have a first accommodating portion 57a ​​in which at least a portion of the heads 46a, 56a of the screw members 46, 56 are accommodated, a threaded engagement portion 57b in which a thread is formed into which the threaded portions of the screw members 46, 56 are screwed, and a second accommodating portion 57c provided between the first accommodating portion 57a ​​and the threaded engagement portion, and formed with a diameter larger than the inner diameter of the thread so that the threaded portions do not screw into the second accommodating portion.

[0058] In this configuration, the second accommodating portion 57c prevents the axial force of the screw members 46, 56 from decreasing.

[0059] Although the embodiments of the present invention have been described above, the above-mentioned embodiments merely show some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above-mentioned embodiments. [Explanation of symbols]

[0060] 15...rotating housing, 20...hydraulic motor (driving source), 31...drive shaft (shaft), 40...planetary gear mechanism, 41...first sun gear (sun gear), 42...inner gear, 43...first planetary gear (planetary gear), 43a...hollow portion, 44...first planetary carrier (support portion), 45...first plate (plate), 46...first screw member (screw member), 46a...head, 47...first receiving hole (receiving hole) , 51... second sun gear (sun gear), 53... second planetary gear (planetary gear), 53a... hollow portion, 54... second planetary carrier (support portion), 55... second plate (plate), 55a... stopper portion, 55b... retaining portion, 56... second screw member (screw member), 56a... head, 56c... threaded portion, 57... second accommodating hole (accommodating hole), 57a... first accommodating portion, 57b... screw-in portion, 57c... second accommodating portion, 100... transmission

Claims

1. a shaft to which output rotation of a drive source is transmitted; a planetary gear mechanism connected to the shaft and configured to change the speed of the output rotation of the drive source; a cylindrical rotating housing that accommodates the planetary gear mechanism and is rotated by the output rotation that has been changed in speed, The planetary gear mechanism includes: a sun gear to which the power of the drive source is transmitted via the shaft; an inner gear formed on an inner circumferential surface of the rotating housing; a plurality of annular planetary gears each having a hollow portion and meshing with both the sun gear and the inner gear; a plurality of support portions that are inserted into the hollow portions of the plurality of planetary gears to support the planetary gears, The support portion includes: a plate that covers at least a portion of the planetary gear and prevents the planetary gear from coming off the support portion; a screw member for fixing the plate to the support portion, The transmission, wherein the support portion has an accommodating hole in which at least a portion of a head of the screw member and a portion of the plate are accommodated.

2. 2. The transmission of claim 1, The plate is a retaining portion that covers at least a portion of the planetary gear; a retaining portion that is received in the receiving hole and is sandwiched and held between an inner circumferential surface of the receiving hole and the head portion of the screw member, A transmission, wherein the anti-slip portion and the retaining portion are bent by plastic deformation.

3. 3. The transmission according to claim 2, The plate is provided in a state in which the holding portion is bent and elastically deformed.

4. 2. The transmission of claim 1, The receiving hole is a first receiving portion in which at least a portion of the head of the screw member is received; A screw-engagement portion having a thread formed thereon into which the screw portion of the screw member is screwed; a second accommodating portion provided between the first accommodating portion and the screw-threaded portion, the second accommodating portion having a diameter larger than an inner diameter of the thread so that the screw portion does not screw into the second accommodating portion.

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