Speed reducer, drive device, and construction machine

Abstract

A speed reducer (10) according to one embodiment is provided with: a carrier (11); a first housing (20) that surrounds the outer peripheral surface of the carrier (11) between both end surfaces of the carrier (11) and is held by the carrier (11) so as to be rotatable relative to the carrier (11) between both end surfaces of the carrier (11); a second housing (30) that surrounds the outer peripheral surface of the carrier (11) and is held by the carrier (11) so as to be rotatable relative to the carrier (11) at a position different from the holding position of the first housing (20) between both end surfaces of the carrier (11); a first speed reduction unit (40) that is held by the carrier (11) and includes a first input unit that inputs rotation from a first side (FS) to which one of the two end surfaces of the carrier (11) faces; and a second speed reduction unit (50) that is held by the carrier (11) and includes a second input unit that inputs rotation from a second side (SS) to which the other of the two end surfaces of the carrier (11) faces.

Description

Technical Field

[0001] The invention relates to a speed reducer, a driving device and a construction machine. Background Art

[0002] The demand for electric construction machinery is increasing. For example, electric excavators have been put into practical use. The excavator has a working element, which includes a boom, a dipper arm, and a bucket. When the working element is operated by an electric motor, for example, the electric motor can be configured in such a way that the rotating shaft integrated with the bucket is coaxial with the driving shaft of the electric motor. In addition, the driving shaft of the electric motor can also rotate the rotating shaft of the bucket with the aid of a speed reducer.

[0003] In the above structure, the electric motor and the reducer can also be arranged inside the bucket. However, in this arrangement, the volume of the bucket becomes smaller, and the efficiency of the excavation operation is reduced. In addition, when the electric motor and the reducer are arranged outside the bucket, the electric motor and the reducer are easy to contact the ground and structures as the operation object. Therefore, the risk of damage to the electric motor and the reducer increases.

[0004] On the other hand, the electric motor for the arm may be arranged so that the rotating shaft provided at the base end portion of the arm connected to the top end portion of the boom is coaxial with the driving shaft of the electric motor for the arm, and the electric motor for the bucket may be arranged so that the rotating shaft of the arm and the driving shaft of the electric motor for the arm are connected via a speed reducer and the electric motor for the bucket is adjacent to the electric motor for the arm. Furthermore, the driving shaft of the electric motor for the bucket may also rotate the bucket connected via a connecting rod mechanism and a speed reducer.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 11-343642 Summary of the invention

[0008] In a structure where the arm electric motor and the bucket electric motor are arranged adjacent to each other, the arm electric motor transmits torque to the arm at the connection point between the base end of the arm and the top end of the boom, and the bucket electric motor transmits torque to the bucket from the vicinity of the connection point. In this case, the bucket electric motor is away from the bucket, so the above-mentioned problem of reduced bucket volume can be eliminated.

[0009] However, although the electric motor for the arm and the electric motor for the bucket are concentrated, the range occupied by the electric motor for the arm and the reducer connected to the electric motor for the arm, and the electric motor for the bucket and the reducer connected to the electric motor for the bucket becomes larger. In this case, for example, since the electric motor for the arm and the electric motor for the bucket extend greatly relative to the arm, the risk of damage to the electric motor for the arm and the electric motor for the bucket increases. On the other hand, when the motor and the reducer are made small, it may not be possible to transmit the desired torque.

[0010] The present invention has been made in consideration of the above-mentioned actual situation, and an object of the present invention is to provide a speed reducer, a drive device, and a construction machine that can suppress enlargement, transmit torque to a plurality of components simultaneously, and easily transmit a desired torque.

[0011] A reducer in one embodiment comprises: a gear rack; a first housing, which surrounds the outer peripheral surface of the gear rack between the two end surfaces of the gear rack and is held on the gear rack between the two end surfaces in a manner that is relatively rotatable relative to the gear rack; a second housing, which surrounds the outer peripheral surface of the gear rack and is held on the gear rack at a position between the two end surfaces of the gear rack that is different from the holding position of the first housing in a manner that is relatively rotatable relative to the gear rack; a first reduction section, which includes a first input section, which is held on the gear rack and inputs rotation from a first side facing one of the two end surfaces of the gear rack, and the first reduction section reduces the rotation input to the first input section and outputs it to the first housing; and a second reduction section, which includes a second input section, which is held on the gear rack and inputs rotation from a second side facing the other end surface of the two end surfaces of the gear rack, and the second reduction section reduces the rotation input to the second input section and outputs it to the second housing.

[0012] A first rotation axis of the first housing relative to the gear carrier and a second rotation axis of the second housing relative to the gear carrier may be located on the same straight line.

[0013] The first housing may be located between the two end surfaces of the gear carrier, and the second housing may be located between the two end surfaces of the gear carrier.

[0014] The carrier may include a first carrier half body that holds the first speed reduction portion and a second carrier half body that holds the second speed reduction portion, which are detachably connected.

[0015] It can also be that the first gear rack half includes a first flange portion extending from between the first shell and the second shell toward the radial outside of the first shell relative to the first shell and toward the radial outside of the second shell relative to the second shell, and the second gear rack half includes a second flange portion extending from between the first shell and the second shell toward the radial outside of the first shell relative to the first shell and toward the radial outside of the second shell relative to the second shell, and the first gear rack half and the second gear rack half are connected by a fastening member spanning the first flange portion and the second flange portion.

[0016] The gear carrier may be partially exposed from between the first housing and the second housing.

[0017] It may also be that the first shell includes a first mounting portion, the first mounting portion is located between the one end surface of the gear rack and the surface of the first shell facing the second shell side, and a predetermined component is installed, and the second shell includes a second mounting portion, the second mounting portion is located between the other end surface of the gear rack and the surface of the second shell facing the first shell side, and other predetermined components are installed.

[0018] The speed reducer according to one embodiment may further include a seal provided between the first housing and the second housing.

[0019] The first input portion may be a shaft member or a driven gear supported by the gear carrier.

[0020] In addition, a driving device according to one embodiment includes: the speed reducer; a first motor that inputs rotation to the first input portion of the first speed reduction portion; and a second motor that inputs rotation to the second input portion of the second speed reduction portion.

[0021] Furthermore, a construction machine according to an embodiment includes a working element including the speed reducer.

[0022] It can also be that the working element includes a first part, a second part and a third part, the reducer is held in the first part, the second part is mounted on the first shell, the third part is rotatably supported on the second part, and the third part is connected to the second shell by a connecting rod device.

[0023] In addition, a construction machine according to an embodiment includes: the speed reducer; and a working element connected to the speed reducer.

[0024] Alternatively, the operating element includes: a side portion, which is mounted on the first shell and extends radially outward of the first shell; and another side portion, which is rotatably supported on the one side portion, and the other side portion is connected to the second shell by means of a connecting rod device.

[0025] According to the present invention, it is possible to transmit torque to each of a plurality of members while suppressing an increase in size, and to facilitate transmission of a desired torque. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a cross-sectional view of a drive device including a speed reducer according to the first embodiment.

[0027] Figure 2 It is a cross-sectional view of a drive device including a speed reducer according to a second embodiment.

[0028] Figure 3 It is a cross-sectional view of a drive device including a speed reducer according to a third embodiment.

[0029] Figure 4 This is a diagram showing a construction machine including the drive device according to the first embodiment.

[0030] Figure 5 This is a diagram showing another construction machine including the drive device according to the first embodiment. DETAILED DESCRIPTION

[0031] Hereinafter, each embodiment of the present invention will be described.

[0032] <First embodiment>

[0033] Figure 1 A driving device 1 including a speed reducer 10 according to a first embodiment is shown. The driving device 1 includes the speed reducer 10 , a first motor 110 , and a second motor 120 .

[0034] The speed reducer 10 includes a gear frame 11, a first housing 20, a second housing 30, a first speed reducing unit 40, and a second speed reducing unit 50. The first housing 20 and the second housing 30 are held on the gear frame 11 in a manner that allows relative rotation with respect to the gear frame 11. The first speed reducing unit 40 is connected to the first motor 110. The second speed reducing unit 50 is connected to the second motor 120.

[0035] The first speed reduction unit 40 receives rotation from the first motor 110. The first speed reduction unit 40 reduces the speed of the rotation received and outputs the rotation to the first housing 20. As a result, the first housing 20 rotates relative to the gear frame 11. The second speed reduction unit 50 receives rotation from the second motor 120. The second speed reduction unit 50 reduces the speed of the rotation received and outputs the rotation to the second housing 30. As a result, the second housing 30 rotates relative to the gear frame 11.

[0036] The gear frame 11 includes a first end face 11A, a second end face 11B on the opposite side of the first end face 11A, and an outer peripheral surface 11C located between the first end face 11A and the second end face 11B. The outer peripheral surface 11C includes a first support surface 11C1 with a circular cross section and a second support surface 11C2 with a circular cross section. The first bearing 12A is outer-mounted on the first support surface 11C1. The second bearing 12B is outer-mounted on the second support surface 11C2.

[0037] The first bearing 12A includes an inner ring, an outer ring, and a plurality of rolling elements held between the inner ring and the outer ring. The first housing 20 is cylindrical or annular. The inner circumferential surface of the first housing 20 is fitted over the outer ring of the first bearing 12A. Thus, the first housing 20 is held on the gear frame 11 in a manner that allows relative rotation relative to the gear frame 11.

[0038] The second bearing 12B includes an inner ring, an outer ring, and a plurality of rolling elements held between the inner ring and the outer ring. The second housing 30 is cylindrical or annular. The inner circumferential surface of the second housing 30 is fitted over the outer ring of the second bearing 12B. Thus, the second housing 30 is held on the gear frame 11 in a manner that allows relative rotation relative to the gear frame 11.

[0039] The first housing 20 and the second housing 30 are held on the gear frame 11 at different positions between the two end faces (the first end face 11A and the second end face 11B) of the gear frame 11 so as to be relatively rotatable with respect to the gear frame 11. Specifically, the first housing 20 is held at a position closer to the first end face 11A of the gear frame 11 than the second housing 30. The second housing 30 is held at a position closer to the second end face 11B of the gear frame 11 than the first housing 20.

[0040] Figure 1 The reference numeral C1 in the figure indicates the first rotation axis of the first housing 20 relative to the gear frame 11. The reference numeral C2 indicates the second rotation axis of the second housing 30 relative to the gear frame 11. The first rotation axis C1 passes through the center of the first support surface 11C1 and the first bearing 12A. The second rotation axis C2 passes through the center of the second support surface 11C2 and the second bearing 12B.

[0041] The first rotation axis C1 of the first housing 20 and the second rotation axis C2 of the second housing 30 are located on the same straight line. That is, the first housing 20 and the second housing 30 are located on the same axis. However, the first rotation axis C1 of the first housing 20 and the second rotation axis C2 of the second housing 30 may be parallel to each other but offset. In addition, the first rotation axis C1 of the first housing 20 and the second rotation axis C2 of the second housing 30 may also intersect.

[0042] In this specification, the first end face 11A is a face of the gear frame 11 that faces the side opposite to the second housing 30 in the axial direction of the first housing 20 extending along the first rotation axis C1, and means a face facing the outside of the gear frame 11. The second end face 11B is a face of the gear frame 11 that faces the side opposite to the first housing 20 in the axial direction of the second housing 30 extending along the second rotation axis C2, and means a face facing the outside of the gear frame 11.

[0043] In this specification, as a term for describing the position relative to the carrier 11, the side facing the first end surface 11A of the carrier 11 is referred to as the first side FS, and the side facing the second end surface 11B of the carrier 11 is referred to as the second side SS.

[0044] The first end face 11A in this embodiment includes portions offset from each other in the axial direction of the first housing 20, and as an example, the two portions are connected by a connecting surface extending in the axial direction of the first housing 20. The second end face 11B also has the same shape as the first end face 11A. However, the first end face 11A and the second end face 11B may be surfaces extending to form the same plane.

[0045] The gear frame 11 includes a first end plate 13, a second end plate 14, and a connecting portion 15 connecting the first end plate 13 and the second end plate 14. The connecting portion 15 includes: a base portion 15A, which is located between the first end plate 13 and the second end plate 14; a first column portion 15B, which extends from the base portion 15A toward the first end plate 13; and a second column portion 15C, which extends from the base portion 15A toward the second end plate 14. In the present embodiment, the base portion 15A, the first column portion 15B, and the second column portion 15C are formed by one member. That is, the base portion 15A, the first column portion 15B, and the second column portion 15C are configured as a seamless component. The base portion 15A, the first column portion 15B, and the second column portion 15C can also be formed integrally, for example, by casting.

[0046] The first end plate 13, the second end plate 14, and the base portion 15A in the connecting portion 15 are respectively roughly cylindrical or annular. In addition, the first end plate 13, the second end plate 14, and the base portion 15A may sometimes be solid cylindrical or disc-shaped according to specifications, especially according to the specifications of the first speed reduction portion 40 and the second speed reduction portion 50.

[0047] The first end plate 13 includes a first end surface 11A. The second end plate 14 includes a second end surface 11B. The first support surface 11C1 of the gear frame 11 supporting the first housing 20 is formed across the first end plate 13 and the base portion 15A in the connecting portion 15. The second support surface 11C2 of the gear frame 11 supporting the second housing 30 is formed across the second end plate 14 and the base portion 15A in the connecting portion 15.

[0048] The first support surface 11C1 includes an outer support surface 131 in the first end plate 13 and an inner support surface 15A1 in the base portion 15A. In addition, two first bearings 12A are provided. One of the two first bearings 12A is outer-mounted on the outer support surface 131, and the other is outer-mounted on the inner support surface 15A1. In addition, the second support surface 11C2 of the gear frame 11 includes an outer support surface 141 in the second end plate 14 and an inner support surface 15A2 in the base portion 15A. In addition, two second bearings 12B are provided. One of the two second bearings 12B is outer-mounted on the outer support surface 141, and the other is outer-mounted on the inner support surface 15A2.

[0049] The first end plate 13 includes a first motor mounting portion 132 formed on the first end surface 11A. The first motor mounting portion 132 connects the first motor 110 to the gear frame 11. The first motor mounting portion 132 is formed on the outer peripheral side portion of the first end surface 11A. The first motor mounting portion 132 may also be a portion having a hole that accommodates a partial fastening member that passes through the first motor 110. The second end plate 14 includes a second motor mounting portion 142. The second motor mounting portion 142 connects the second motor 120 to the gear frame 11. The structure of the second motor mounting portion 142 has the same structure as that of the first motor mounting portion 132, except that the formation position is different.

[0050] The connection portion 15 is connected to the first end plate 13 by a fastening member inserted from the first end surface 11A of the first end plate 13 and straddling the first end plate 13 and the first column portion 15B. The connection portion 15 is connected to the second end plate 14 by a fastening member inserted from the second end surface 11B of the second end plate 14 and straddling the second end plate 14 and the second column portion 15C.

[0051] The connecting portion 15 includes a plurality of first column portions 15B and a plurality of second column portions 15C. The plurality of first column portions 15B are arranged at intervals in the circumferential direction of the base portion 15A at the surface of the base portion 15A facing the first end plate 13. The plurality of second column portions 15C are arranged at intervals in the circumferential direction of the base portion 15A at the surface of the base portion 15A facing the second end plate 14. Any one of the plurality of first column portions 15B and any one of the plurality of second column portions 15C are arranged in a straight line.

[0052] In addition, an inner crankshaft support hole 15A3 penetrating the base portion 15A is provided at a position where the column portions 15B and 15C are not formed on the surface of the base portion 15A facing the first end plate 13 and the surface facing the second end plate 14. A first outer crankshaft support hole 133 facing the inner crankshaft support hole 15A3 is provided in the first end plate 13. A second outer crankshaft support hole 143 facing the inner crankshaft support hole 15A3 is provided in the second end plate 14.

[0053] The inner crankshaft support hole 15A3 and the first outer crankshaft support hole 133 support the first crankshaft 43 (discussed below) inserted into the inner side of each of the first reduction section 40 via bearings so as to be rotatable. The inner crankshaft support hole 15A3 and the second outer crankshaft support hole 143 support the second crankshaft 53 (discussed below) inserted into the inner side of each of the second reduction section 50 via bearings so as to be rotatable.

[0054] In addition, as described above, the first end plate 13, the second end plate 14, and the base portion 15A in the connecting portion 15 are each substantially cylindrical or annular. The inner circumferential surface of the first end plate 13 and the inner circumferential surface of the base portion 15A form a support hole, which supports the first central shaft 41 (to be discussed later) constituting the first speed reduction portion 40 via a bearing so as to be rotatable. The inner circumferential surface of the second end plate 14 and the inner circumferential surface of the base portion 15A form a support hole, which supports the second central shaft 51 (to be discussed later) constituting the second speed reduction portion 50 via a bearing so as to be rotatable.

[0055] The center lines of the inner crankshaft support hole 15A3, the first outer crankshaft support hole 133, and the second outer crankshaft support hole 143 are parallel to the first rotation axis C1 and the second rotation axis C2. In addition, the center lines of the inner circumference of the first end plate 13, the inner circumference of the base portion 15A, and the inner circumference of the second end plate 14 are also parallel to the first rotation axis C1 and the second rotation axis C2.

[0056] The first housing 20 is cylindrical. The first housing 20 is held on the first supporting surface 11C1 in the outer peripheral surface 11C of the above-mentioned gear frame 11 in a manner that is relatively rotatable relative to the above-mentioned gear frame 11. In this state, the first housing 20 surrounds a portion of the outer peripheral surface 11C of the gear frame 11. And, in the present embodiment, the first housing 20 is located between the first end surface 11A and the second end surface 11B of the gear frame 11. That is, the first housing 20 does not extend from the first end surface 11A of the gear frame 11 to the first side FS. The first housing 20 does not extend from the second end surface 11B of the gear frame 11 to the second side SS. In addition, the first housing 20 does not overlap with the second housing 30 in the radial direction of the second housing 30. That is, the first housing 20 does not face any part of the second housing 30 in the radial direction of the second housing 30.

[0057] The first housing 20 includes a first mounting portion 21 including a fastening hole 21A extending parallel to the first rotation axis C1. The first mounting portion 21 is capable of fixing and retaining, for example, an arm member, a connecting rod member, etc. The first mounting portion 21 is disposed on the outer peripheral side portion of the first housing 20. The first mounting portion 21 is located between the first end face 11A of the gear frame 11 and the surface of the first housing 20 facing the second housing 30 side. That is, the first mounting portion 21 does not extend from the first end face 11A of the gear frame 11 to the first side FS. The first mounting portion 21 does not overlap with the second housing 30 in the radial direction of the second housing 30. That is, the first mounting portion 21 does not face any part of the second housing 30 in the radial direction of the second housing 30.

[0058] In addition, the second housing 30 is also cylindrical. The second housing 30 is held on the second supporting surface 11C2 in the outer peripheral surface 11C of the above-mentioned gear frame 11 in a manner that is relatively rotatable relative to the above-mentioned gear frame 11. In this state, the second housing 30 surrounds a portion of the outer peripheral surface 11C of the gear frame 11. In detail, the second housing 30 surrounds a portion of the outer peripheral surface 11C of the gear frame 11 that is different from the portion surrounded by the first housing 20.

[0059] Furthermore, in the present embodiment, the second housing 30 is located between the first end face 11A and the second end face 11B of the gear frame 11. That is, the second housing 30 does not extend from the second end face 11B of the gear frame 11 to the second side SS. The second housing 30 does not extend from the first end face 11A of the gear frame 11 to the first side FD. In addition, the second housing 30 does not overlap with the first housing 20 in the radial direction of the first housing 20. That is, the second housing 30 does not face any part of the first housing 20 in the radial direction of the first housing 20.

[0060] The second housing 30 includes a second mounting portion 31 including a fastening hole 31A extending parallel to the second rotation axis C2. The second mounting portion 31 is capable of fixing and retaining, for example, an arm member, a connecting rod member, etc. The second mounting portion 31 is disposed on the outer peripheral side portion of the second housing 30. The second mounting portion 31 is located between the second end face 11B of the gear frame 11 and the surface of the second housing 30 facing the first housing 20 side. That is, the second mounting portion 31 does not extend from the second end face 11B of the gear frame 11 to the second side SS. The second mounting portion 31 does not overlap with the first housing 20 in the radial direction of the first housing 20. That is, the second mounting portion 31 does not face any part of the first housing 20 in the radial direction of the first housing 20.

[0061] In addition, a seal 60 is provided between the first housing 20 and the second housing 30. The seal 60 is sandwiched by the mutually opposing surfaces of the first housing 20 and the second housing 30. Specifically, the end surface of the first housing 20 facing the second housing 30 and the end surface of the second housing 30 facing the first housing 20 face each other. A first groove 22 extending over the entire circumferential region of the first housing 20 is formed on the end surface of the first housing 20 facing the second housing 30. A second groove 32 extending over the entire circumferential region of the second housing 30 is formed on the end surface of the second housing 30 facing the first housing 20. The seal 60 is partially accommodated in the first groove 22 and partially accommodated in the second groove 32. Thus, the seal 60 is held between the first housing 20 and the second housing 30 in a state of straddling the first groove 22 and the second groove 32.

[0062] The sealing member 60 is generally annular. Figure 1 As shown, it can also be composed of a floating seal. In this case, the seal 60 includes a pair of sealing rings and a pair of O-rings. Furthermore, one of the pair of sealing rings and one of the pair of O-rings are housed in the first groove 22, and the other of the pair of sealing rings and the other of the pair of O-rings are housed in the second groove 32. The sealing ring is wedge-shaped. The sealing ring housed in the first groove 22 is arranged in a manner such that the inclined surface faces the inner surface of the first groove 22, and the O-ring is held between the inner surface of the first groove 22 and the inclined surface of the sealing ring. The sealing ring and the O-ring housed in the second groove 32 are also arranged in the same manner as the first groove 22 side. Furthermore, the sealing ring housed in the first groove 22 and the sealing ring housed in the second groove 32 abut against each other. In addition, there is no particular limitation on the seal 60 as long as it can allow the first shell 20 and the second shell 30 to rotate independently.

[0063] As an example, the speed reducer 10 is configured as an eccentric oscillating type speed reducer. Therefore, the first speed reducing portion 40 and the second speed reducing portion 50 each include an eccentric oscillating gear.

[0064] The first speed reduction portion 40 includes a first center shaft 41 , a first input gear 42 , a first crankshaft 43 , a first relay gear 44 , and a first external gear 45 serving as an eccentric oscillation gear.

[0065] The first center shaft 41 is rotatably held by the inner circumference of the first end plate 13 and the inner circumference of the base portion 15A via a bearing. The first center shaft 41 extends toward the first side FS from the first end face 11A of the gear frame 11. A first input gear 42 is provided at a portion of the first center shaft 41 extending from the first end face 11A.

[0066] The first crankshaft 43 is rotatably held in the inner crankshaft support hole 15A3 in the first end plate 13 and the first outer crankshaft support hole 133 in the connecting portion 15 by means of a bearing. The first crankshaft 43 extends from the first end face 11A of the gear frame 11 to the first side FS. A first relay gear 44 is provided at a portion of the first crankshaft 43 extending from the first end face 11A. The first relay gear 44 meshes with the first input gear 42. The first external gear 45 is provided at a portion of the first crankshaft 43 located between the first end plate 13 and the base portion 15A of the connecting portion 15. The first external gear 45 meshes with an internal gear provided to the inner circumferential surface of the first housing 20.

[0067] In the present embodiment, the first center shaft 41 is connected to the first motor 110. The first center shaft 41 is held by the carrier 11 and corresponds to a so-called first input portion in the present invention, which receives rotation from the first side FS.

[0068] The second reduction section 50 includes a second center shaft 51, a second input gear 52, a second crankshaft 53, a second relay gear 54, and a second external gear 55 serving as an eccentric swing gear. The second center shaft 51 is connected to the second motor 120. The second center shaft 51 corresponds to the so-called second input section in the present invention, which is held on the gear frame 11 and inputs rotation from the second side SS. The components of the second reduction section 50 are the same as the components (41 to 45) of the first reduction section 40. The components of the second reduction section 50 are similarly arranged and held on the gear frame 11, except that the configuration position is different from that of the components of the first reduction section 40. Therefore, a detailed description of the components of the second reduction section 50 is omitted.

[0069] In addition, the reducer 10 of the present embodiment is an eccentric oscillating type reducer of a type in which the crankshaft is offset relative to the rotation center of the housing, but the reducer 10 can also be configured as an eccentric oscillating type reducer of a center crankshaft type. In addition, the reducer 10 can also be configured as a planetary gear type reducer. In this case, the first reduction portion 40 can also include, for example, a planetary gear that rotates due to the rotation input to the first input portion composed of an axial member that rotates integrally with the sun gear. The planetary gear rotates while revolving around the first rotation axis C1 of the first housing 20, and meshes with the internal gear provided on the inner circumferential surface of the first housing 20.

[0070] The first motor 110 is an electric motor. The first motor 110 includes a stator 111, a rotor 112, and a rotating shaft 113 mounted to the rotor 112. The first motor 110 is mounted on the first motor mounting portion 132 in the gear frame 11. The rotor 112 and the rotating shaft 113 are arranged on the inner side of the cylindrical stator 111. The rotor 112 and the rotating shaft 113 rotate integrally relative to the stator 111. The rotating shaft 113 is provided with a hole 114 extending in the axial direction from the end face of the rotating shaft 113. A portion of the outer peripheral surface of the first center shaft 41 as an axis member is embedded in the hole 114. The hole 114 is connected to the first center shaft 41 in a non-rotatable manner. Thus, as the first motor 110 rotates, the first center shaft 41 rotates.

[0071] The second motor 120 is also an electric motor. The second motor 120 includes a stator 121, a rotor 122, and a rotating shaft 123 mounted to the rotor 122. The second motor 120 is mounted on the second motor mounting portion 142 in the gear frame 11. The rotor 122 and the rotating shaft 123 are arranged on the inner side of the cylindrical stator 121. The rotor 122 and the rotating shaft 123 rotate integrally relative to the stator 121. The rotating shaft 123 is provided with a hole 124 extending in the axial direction from the end face of the rotating shaft 123. A portion of the outer peripheral surface of the second center shaft 51 as an axis member is embedded in the hole 124. The hole 124 is connected to the second center shaft 51 in a non-rotatable manner. Thus, as the second motor 120 rotates, the second center shaft 51 rotates.

[0072] An operation example of the drive device 1 according to the present embodiment will be described.

[0073] For example, the gear frame 11 is fixed to other components by using the first end plate 13 and the second end plate 14. In this state, if the rotating shaft 113 of the first motor 110 rotates, the rotation is input to the first center shaft 41. Then, the rotation input to the first center shaft 41 is transmitted to the first crankshaft 43 by means of the first input gear 42 and the first relay gear 44, and the first crankshaft 43 rotates. In addition, the first crankshaft 43 causes the first external gear 45 to swing and rotate. In addition, the rotation that is reduced relative to the rotation when input from the first external gear 45 is output to the first housing 20. As a result, the first housing 20 rotates relative to the gear frame 11.

[0074] In addition, if the rotating shaft 123 of the second motor 120 rotates, the rotation is input to the second center shaft 51. Then, the rotation input to the second center shaft 51 is transmitted to the second crankshaft 53 via the second input gear 52 and the second relay gear 54, and the second crankshaft 53 rotates. In addition, the second crankshaft 53 causes the second external gear 55 to swing and rotate. In addition, the rotation that is reduced in speed relative to the rotation when input from the second external gear 55 is output to the second housing 30. As a result, the second housing 30 rotates relative to the gear frame 11.

[0075] In the present embodiment described above, the first housing 20 and the second housing 30 are held on the outer peripheral surface 11C of the common gear frame 11. Thus, the range occupied by the reducer 10 can be suppressed compared with the case where dedicated gear frames are provided on the first housing 20 and the second housing 30, respectively. Furthermore, by using the first reduction unit 40 and the second reduction unit 50 to rotate the first housing 20 and the second housing 30 respectively relative to the gear frame 11, it is possible to transmit torque from the first housing 20 and the second housing 30 to different components respectively. Furthermore, the first central shaft 41 corresponding to the first input portion of the first reduction unit 40 to which rotation is input from the outside and the second central shaft 51 corresponding to the second input portion of the second reduction unit 50 to which rotation is input from the outside are arranged in a dispersed manner on the gear frame 11. Thus, for example, there is no significant restriction on the size of the first motor 110 connected to the first central shaft 41 and the size of the second motor 120 connected to the second central shaft 51. Therefore, the speed reducer 10 can be connected to the first motor 110 and the second motor 120 of large size that can ensure large output, for example. Therefore, torque can be transmitted to each of the plurality of members while suppressing enlargement, and desired torque can be easily transmitted.

[0076] In addition, the first rotation axis C1 of the first housing 20 relative to the gear frame 11 and the second rotation axis C2 of the second housing 30 relative to the gear frame 11 are located on the same straight line. In this case, the complexity of the shape of the gear frame 11 can be suppressed, and the first housing 20 and the second housing 30 can be held by the gear frame 11. In addition, the first housing 20 is located between the two end surfaces of the gear frame 11, and the second housing 30 is located between the two end surfaces of the gear frame 11. As a result, the size of the reducer 10 can be suppressed.

[0077] In addition, the first housing 20 includes a first mounting portion 21 located between the first end face 11A of the gear frame 11 and the surface of the first housing 20 facing the second housing 30 and on which a predetermined component is mounted. The second housing 30 includes a second mounting portion 31 located between the second end face 11B of the gear frame 11 and the surface of the second housing 30 facing the first housing 20 and on which other predetermined components are mounted. In this structure, the deviation of the load applied to the first reduction section 40 and the second reduction section 50 when a predetermined component is mounted on the first mounting portion 21 and other predetermined components are mounted on the second mounting portion 31 can be suppressed. As a result, the durability of the reducer 10 can be improved.

[0078] In addition, a seal 60 is provided between the first housing 20 and the second housing 30. In this structure, it is possible to suppress the passage of fluids such as hydraulic oil and rain and foreign matter such as soil through the gap between the first housing 20 and the second housing 30. In addition, by sharing the seal 60 in the first housing 20 and the second housing 30, the number of seals can be reduced.

[0079] <Second embodiment>

[0080] Next, refer to Figure 2 , and at the same time, a drive device 2 with a reducer 10' of a second embodiment is described. The same figure marks are marked on the components of this embodiment that are the same as the components of the first embodiment, and repeated descriptions are omitted. In the second embodiment, the structure of the gear frame 11 in the reducer 10' is different from the structure of the gear frame 11 of the first embodiment.

[0081] In the present embodiment, a dividing line Pl extending in the radial direction of the base portion 15A is formed on the base portion 15A of the connecting portion 15. Furthermore, the gear rack 11 includes a first gear rack half 11L and a second gear rack half 11R connected in a manner that can be separated at the dividing line PL. The first gear rack half 11L includes a first end face 11A. The second gear rack half 11R includes a second end face 11B.

[0082] In detail, the base portion 15A in the connecting portion 15 includes a first side portion 151 and a second side portion 152 which can be separated at a dividing line PL. The first column portion 15B is integrated with the first side portion 151. The second column portion 15C is integrated with the second side portion 152. Furthermore, the first gear frame half 11L is composed of the first side portion 151, the first column portion 15B and the first end plate 13. The second gear frame half 11R is composed of the second side portion 152, the second column portion 15C and the second end plate 14. In addition, the dividing line PL is set at a position that does not intersect with the first reduction portion 40 and the second reduction portion 50. Furthermore, the first gear frame half 11L holds the first reduction portion 40. The second gear frame half 11R holds the second reduction portion 50.

[0083] In the present embodiment, the first gear rack half body 11L and the second gear rack half body 11R are connected by a fastening member inserted from the second end face 11B into the second column portion 15C, the second side portion 152, and the first side portion 151. However, the first gear rack half body 11L and the second gear rack half body 11R may also be connected by a fastening member inserted from the first end face 11A.

[0084] In addition, in the present embodiment, the gear rack 11 includes an exposed portion 11E exposed from between the first housing 20 and the second housing 30. The exposed portion 11E is composed of an outer peripheral portion of the first side portion 151 and an outer peripheral portion of the second side portion 152. The outer peripheral portion of the first side portion 151 and the outer peripheral portion of the second side portion 152 constituting the exposed portion 11E are located between the end surface of the first housing 20 and the end surface of the second housing that are opposite to each other. A first side seal 61 is provided between the outer peripheral portion of the first side portion 151 and the end surface of the first housing 20. A second side seal 62 is provided between the outer peripheral portion of the second side portion 152 and the end surface of the second housing 30. The first side seal 61 and the second side seal 62 may also be floating seals as shown in the figure, but there is no particular limitation on their form.

[0085] In the second embodiment, the gear rack 11 includes a first gear rack half 11L that holds the first reduction part 40 and a second gear rack half 11R that holds the second reduction part 50, which are connected in a detachable manner. In this structure, operations such as assembly and disassembly become easy. In addition, a local exposed portion 11E of the gear rack 11 is exposed from between the first shell 20 and the second shell 30. In this structure, the exposed portion 11E can be used as a support point for the reducer 10', and the stability of the reducer 10' can be improved.

[0086] <Third embodiment>

[0087] Next, refer to Figure 3 , and at the same time, a driving device 3 with a reducer 10" of a third embodiment is described. The components of this embodiment that are the same as those of the first and second embodiments are marked with the same figure marks, and repeated descriptions are omitted. In the third embodiment, the structure of the gear rack 11 in the reducer 10" is different from the structure of the gear rack 11 in the first and second embodiments.

[0088] The gear holder 11 in this embodiment includes a first gear holder half 11L and a second gear holder half 11R connected to each other at the dividing line PL as in the second embodiment. However, unlike the second embodiment, the exposed portion 11E of the gear holder 11 extends from the first housing 20 and the second housing 30 .

[0089] In detail, the first gear rack half 11L includes a first flange portion 161 extending from between the first shell 20 and the second shell 30 to the radial outside of the first shell 20 relative to the first shell 20 and to the radial outside of the second shell 30 relative to the second shell. The first flange portion 161 is formed on the first side portion 151. The second gear rack half 11R includes a second flange portion 162 extending from between the first shell 20 and the second shell 30 to the radial outside of the first shell 20 relative to the first shell 20 and to the radial outside of the second shell 30 relative to the second shell 30. The second flange portion 162 is formed on the second side portion 152. Here, radially outer refers to the side away from the center in the radial direction. Radially inner refers to the side close to the center in the radial direction.

[0090] In the present embodiment, the first flange portion 161 and the second flange portion 162 constitute the exposed portion 11E. Furthermore, the first gear frame half body 11L and the second gear frame half body 11R are connected by a fastening member spanning the first flange portion 161 and the second flange portion 162. The position through which the fastening member passes is a position radially outward from the outer peripheral surface of the first housing 20 and a position radially outward from the outer peripheral surface of the second housing 30.

[0091] In the third embodiment, the position for fastening the first gear rack half 11L and the second gear rack half 11R can be arranged on the outer periphery of the first reduction portion 40 and the second reduction portion 50. Thus, for example, after the components constituting the first reduction portion 40 are installed in the first gear rack half 11L and the components constituting the second reduction portion 50 are installed in the second gear rack half 11R, it is possible to easily produce a structure that can connect the first gear rack half 11L and the second gear rack half 11R. Thus, the assembly of the reducer 10" can be facilitated. In addition, the first flange portion 161 and the second flange portion 162 can be used as support points of the reducer 10", and the stability of the reducer 10" can be improved.

[0092] <Construction machinery (1)>

[0093] Figure 4 This is a diagram showing a construction machine M1 equipped with the drive device 1 according to the first embodiment. Figure 4 The construction machine M1 shown is an excavator. The construction machine M1 includes a working element 200 connected to a construction machine body (not shown). The construction machine M1 may include the drive device 2 of the second embodiment or the drive device 3 of the third embodiment.

[0094] The working element 200 includes a boom 201, an arm 202, and a bucket 203. The base end side of the boom 201 is rotatably connected to the main body of the construction machine. The base end side of the arm 202 is connected to the top end side of the boom 201. The base end side of the bucket 203 is connected to the top end side of the arm 202.

[0095] In the construction machine M1, the driving device 1 is installed at the top end of the boom 201. In the present embodiment, as an example, the boom 201 includes: a pair of side plates extending in the longitudinal direction of the boom 201 facing each other; and a connecting plate connecting the pair of side plates. Figure 1 A portion on the front end side of one of the pair of side plates supports the first end plate 13 of the gear frame 11 , and a portion on the front end side of the other of the pair of side plates supports the second end plate 14 of the gear frame 11 .

[0096] Furthermore, in the construction machine M1, a portion of the base end side of the boom 202 is connected to the first housing 20. Thus, the boom 202 rotates around the connection point with the boom 201 according to the rotation of the first housing 20. In addition, the bucket 203 is rotatably connected to the portion of the top end side of the boom 202 by means of a bearing or the like. Furthermore, the bucket 203 is connected to the second housing 30 by means of a first connecting rod device 210. In the example shown in the figure, the bucket 203 rotates around the connection point with the boom 202 by pushing and pulling the first connecting rod device 210 according to the rotation of the second housing 30. In the example shown in the figure, the first connecting rod device 210 is formed by connecting three connecting rods in series. One connecting rod is rotatably connected to one end of the central connecting rod, and another connecting rod is rotatably connected to the other end of the central connecting rod. That is, in the construction machine M1, the reducer 10 is included in the working element 200.

[0097] In the construction machine M1, for the reducer 10 in the drive device 1 disposed at the connection portion between the boom 201 and the arm 202, the first housing 20 and the second housing 30 are maintained on the outer peripheral surface 11C of the common gear frame 11. As a result, the range occupied by the reducer 10 and the drive device 1 can be suppressed. Therefore, the extension amount of the drive device 1 from the boom 201 and the arm 202 is suppressed. Therefore, the risk of contact between the ground and the structure as the working object and the drive device 1 can be suppressed, and the risk of damage to the drive device 1 can be suppressed.

[0098] In addition, as an example, the boom 201 includes a pair of side plates that are opposite to each other and extend in the length direction of the boom 201, and the top end side portion of one of the pair of side plates supports the first end plate 13 of the gear rack 11, and the top end side portion of the other of the pair of side plates supports the second end plate 14 of the gear rack 11. In this case, the speed reducer 10, which is a heavy object, is supported on the boom 201 in a double-supported state. Therefore, the stability of the support state of the speed reducer 10 and the drive device 1 can be improved. In addition, Figure 4 In the example of , the first part in the present invention corresponds to the boom 201 , the second part corresponds to the arm 202 , and the third part corresponds to the bucket 203 .

[0099] <Construction machinery (2)>

[0100] Figure 5 This is a diagram showing a construction machine M2 equipped with the drive device 1 according to the first embodiment. Figure 5 The construction machine M2 shown is an excavator. In the construction machine M2, a drive device 1 is installed on a construction machine body (not shown). In addition, a portion of the base end side of the boom 201 is connected to the first housing 20. Thus, the boom 201 rotates around the connection point with the construction machine body in accordance with the rotation of the first housing 20. In addition, the arm 202 is rotatably connected to the portion of the top end side of the boom 201 by means of a bearing or the like. In addition, the arm 202 is connected to the second housing 30 by means of a second link device 220. In the example shown in the figure, the second link device 220 is pushed and pulled in accordance with the rotation of the second housing 30, so that the arm 202 rotates. In addition, in the construction machine M2, other drive devices and the bucket 203 arranged at the connection position between the boom 201 and the arm 202 are provided. Figure 4 The first linkage device 210 is shown connected.

[0101] In the construction machine M2, Figure 4 The same effect as the effect of the construction machine M1 described in . Figure 5 In the example of the present invention, the one side portion corresponds to the boom 201, and the other side portion corresponds to the arm 202.

[0102] In addition, the form of the present invention is not limited to the above-mentioned embodiments, but also includes various deformations that can be thought of by those skilled in the art, and the effect of the present invention is not limited to the above-mentioned contents. That is, various additions, changes and partial deletions can be made within the scope of the conceptual ideas and the main purpose of the present invention derived from the contents specified in the claims and their equivalents. In the embodiments disclosed in this specification, a component composed of multiple objects can make the multiple objects integrated, and conversely, a component composed of one object can be divided into multiple objects. Regardless of whether it is integrated or not, it can be constructed in a manner that can achieve the purpose of the invention.

[0103] For example, in the above-mentioned embodiment, a part of the outer peripheral surface of the first center shaft 41 is embedded in the hole 114 provided in the rotating shaft 113 of the first motor 110. And the hole 114 is connected to the first center shaft 41 in a non-rotatable manner. Alternatively, a hole extending in the axial direction from the end surface of the first center shaft 41 may be formed in the first center shaft 41, and the rotating shaft 113 may be inserted into the hole. In this case, the first center shaft 41 also corresponds to the first input unit.

[0104] In addition, the first speed reduction unit 40 in the speed reducer 10 may not include the first center shaft 41 and the first input gear 42. In this case, the driving gear provided to the rotating shaft 113 of the first motor 110 may mesh with the first relay gear 44 to transmit the rotation. In this case, the first relay gear 44 serving as the driven gear corresponds to the first input unit.

[0105] Description of Reference Numerals

[0106] 1, 2, 3, driving device; 10, 10', 10", speed reducer; 11, gear rack; 11A, first end face; 11B, second end face; 11C, outer peripheral surface; 11C1, first support surface; 11C2, second support surface; 11L, first gear rack half; 11R, second gear rack half; 11E, exposed portion; 12A, first bearing; 12B, second bearing; 13, first end plate; 131, outer support surface; 132, first motor mounting portion; 133, first outer crankshaft support hole ; 14, second end plate; 141, outer supporting surface; 142, second motor mounting portion; 143, second outer crankshaft supporting hole; 15, connecting portion; 15A, base portion; 15A1, 15A2, inner supporting surface; 15A3, inner crankshaft supporting hole; 15B, first column portion; 15C, second column portion; 151, first side portion; 152, second side portion; 161, first flange portion; 162, second flange portion; 20, first housing; 21, first mounting portion; 21A, fastening hole ; 22, first groove; 30, second housing; 31, second mounting portion; 31A, fastening hole; 32, second groove; 40, first speed reduction portion; 41, first center shaft; 42, first input gear; 43, first crankshaft; 44, first relay gear; 45, first external gear; 50, second speed reduction portion; 51, second center shaft; 52, second input gear; 53, second crankshaft; 54, second relay gear; 55, second external gear; 60, seal; 61, first side seal; 62, second side seal Seal; 110, first motor; 111, stator; 112, rotor; 113, rotating shaft; 114, hole; 120, second motor; 121, stator; 122, rotor; 123, rotating shaft; 124, hole; C1, first rotating axis; C2, second rotating axis; FS, first side; SS, second side; M1, M2, construction machinery; 200, working element; 201, boom; 202, arm; 203, bucket; 210, first connecting rod device; 220, second connecting rod device.

Claims

1. A reducer, wherein: The reducer has: Gear rack; a first housing which surrounds the outer peripheral surface of the gear rack between the two end surfaces of the gear rack and is held by the gear rack between the two end surfaces of the gear rack in a manner that allows relative rotation with respect to the gear rack; a second housing surrounding the outer peripheral surface of the gear rack and being held by the gear rack at a position between the two end surfaces of the gear rack different from the holding position of the first housing so as to be relatively rotatable with respect to the gear rack; a first speed reduction unit including a first input unit, the first input unit being held by the gear frame and inputting rotation from a first side facing one of the two end faces of the gear frame, the first speed reduction unit reducing the rotation input to the first input unit and outputting the rotation to the first housing; and The second reduction unit includes a second input unit, which is held by the gear frame and receives rotation from a second side facing the other end face of the gear frame. The second reduction unit reduces the rotation input to the second input unit and outputs the rotation to the second housing.

2. The reducer according to claim 1, wherein: A first rotation axis of the first housing relative to the gear carrier and a second rotation axis of the second housing relative to the gear carrier are located on the same straight line.

3. The reducer according to claim 1, wherein: The first housing is located between the two end surfaces of the gear rack. The second housing is located between the two end surfaces of the gear carrier.

4. The reducer according to claim 1, wherein: The carrier includes a first carrier half body that holds the first speed reduction portion and a second carrier half body that holds the second speed reduction portion and that are detachably connected.

5. The reducer according to claim 4, wherein: The first gear carrier half body includes a first flange portion extending from between the first housing and the second housing toward the radially outer side of the first housing relative to the first housing and toward the radially outer side of the second housing relative to the second housing. The second gear carrier half body includes a second flange portion extending from between the first housing and the second housing toward the radially outer side of the first housing relative to the first housing and toward the radially outer side of the second housing relative to the second housing. The first gear carrier half body and the second gear carrier half body are connected by a fastening member straddling the first flange portion and the second flange portion.

6. The reducer according to claim 1, wherein: A portion of the gear carrier is exposed from between the first housing and the second housing.

7. The reducer according to claim 1, wherein: The first housing includes a first mounting portion, the first mounting portion is located between the one end surface of the gear rack and a surface of the first housing facing the second housing side, and is mounted with a predetermined member. The second housing includes a second mounting portion that is located between the other end surface of the gear holder and a surface of the second housing that faces the first housing and to which another predetermined member is mounted.

8. The reducer according to claim 1, wherein: The speed reducer further includes a seal provided between the first housing and the second housing.

9. The reducer according to claim 1, wherein: The first input portion is a shaft member or a driven gear supported by the gear carrier.

10. A driving device, wherein: The drive device has: The reducer according to any one of claims 1 to 9; a first motor that inputs rotation to the first input portion of the first speed reduction portion; and A second motor inputs rotation to the second input portion of the second speed reduction portion.

11. A construction machine, wherein: The construction machine includes a working element, and the working element includes the speed reducer according to claim 1.

12. The construction machine according to claim 11, wherein: The operating element comprises a first part, a second part and a third part, The speed reducer is held by the first portion, the second portion is mounted on the first housing, and the third portion is rotatably supported by the second portion. The third portion is connected to the second housing via a link device.

13. A construction machine, wherein: The construction machinery has: The reducer according to any one of claims 1 to 9; and A working element is connected with the reducer.

14. The construction machine according to claim 11, wherein: The operating element includes: a side portion, which is mounted on the first housing and extends radially outward from the first housing; and another side portion, which is rotatably supported on the side portion. The other side portion is connected to the second housing via a link device.

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