Reducer, drive unit, and construction machine

Abstract

A speed reducer 10 of one embodiment comprises: a carrier 11; a first case 20 that surrounds an outer peripheral surface of the carrier 11 located between both end surfaces of the carrier 11, and is relatively rotatably held by the carrier 11 between the both end surfaces of the carrier 11; a second case 30 that surrounds the outer peripheral surface of the carrier 11, and is relatively rotatably held by the carrier 11 at a position different from the position at which the first case 20 is held between the both end surfaces of the carrier 11; a first reduction part 40 including a first input part which is held by the carrier 11 and to which a rotation is input from a first side FS facing one of the both end surfaces of the carrier 11; and a second reduction part 50 including a second input part which is held by the carrier 11 and to which a rotation is input from a second side SS facing the other end surface of the both end surfaces of the carrier 11.

Description

[Technical Field]

[0001] The present invention relates to a reducer, a drive device, and a construction machine. [Background technology]

[0002] Demand for electric construction machinery is increasing. For example, electric shovels are already in practical use. An shovel has working elements including a boom, an arm, and a bucket. When these working elements are operated by an electric motor, the electric motor may be arranged so that the rotating shaft integrated with the bucket and the drive shaft of the electric motor are coaxial. The drive shaft of the electric motor may then rotate the rotating shaft of the bucket via a reducer.

[0003] In the above configuration, the electric motor and the reducer may be disposed inside the bucket. However, this arrangement reduces the bucket's volume and reduces the efficiency of excavation work. Furthermore, if the electric motor and the reducer are disposed outside the bucket, they are more likely to come into contact with the ground or structures that are the work target. This increases the risk of damage to the electric motor and the reducer.

[0004] Alternatively, the electric motor for the arm may be arranged so that a rotary shaft provided at a base end of an arm connected to the tip end of the boom and a drive shaft of the electric motor for the arm are coaxial, the rotary shaft of the arm and the drive shaft of the electric motor for the arm are connected via a reducer, and the electric motor for the bucket may be arranged adjacent to the electric motor for the arm. The drive shaft of the electric motor for the bucket may then rotate the bucket connected via a reducer and a link mechanism. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 11-343642 Summary of the Invention

[0006] In a configuration in which the arm electric motor and the bucket electric motor are arranged side by side, the arm electric motor transmits torque to the arm at the connection point between the arm and the base end of the arm, which is connected to the tip of the boom, and the bucket electric motor transmits torque to the bucket from near this connection point. In this case, the bucket electric motor is located away from the bucket, which solves the above-mentioned problem of a small bucket volume.

[0007] However, although the arm electric motor and the bucket electric motor are integrated, the area occupied by the arm electric motor and the reducer connected thereto, and the bucket electric motor and the reducer connected thereto, increases. In this case, for example, the arm electric motor or the bucket electric motor protrudes significantly from the arm, increasing the risk of damage to the arm electric motor or the bucket electric motor. On the other hand, if the motors and reducers are made smaller, there is a risk that they will not be able to transmit the desired torque.

[0008] The present invention has been made in consideration of the above-mentioned circumstances, and aims to provide a reducer, a drive unit, and a construction machine that can transmit torque separately to multiple members while preventing the device from becoming too large, and that can easily transmit the desired torque.

[0009] A reducer according to one embodiment includes a carrier, a first case surrounding the outer peripheral surface of the carrier between both end faces of the carrier and held rotatably relative to the carrier between the both end faces of the carrier, a second case surrounding the outer peripheral surface of the carrier and held rotatably relative to the carrier at a position different from the holding position of the first case between the both end faces of the carrier, a first reduction unit held by the carrier and including a first input unit that receives rotation from a first side facing one of the both end faces of the carrier, and that decelerates the rotation input to the first input unit and outputs it to the first case, and a second reduction unit held by the carrier and including a second input unit that receives rotation from a second side facing the other of the both end faces of the carrier, and that decelerates the rotation input to the second input unit and outputs it to the second case.

[0010] A first rotation axis of the first case relative to the carrier and a second rotation axis of the second case relative to the carrier may be positioned on the same straight line.

[0011] The first case may be located between the two end faces of the carrier, and the second case may be located between the two end faces of the carrier.

[0012] The carrier may include a first carrier half that holds the first reduction gear portion and a second carrier half that holds the second reduction gear portion, which are separably connected.

[0013] The first carrier half may include a first flange portion extending from between the first case and the second case radially outward from the first case relative to the first case and radially outward from the second case relative to the second case, and the second carrier half may include a second flange portion extending from between the first case and the second case radially outward from the first case relative to the first case and radially outward from the second case relative to the second case, and the first carrier half and the second carrier half may be connected by a fastening member spanning the first flange portion and the second flange portion.

[0014] A portion of the carrier may be exposed between the first case and the second case.

[0015] The first case may include a first mounting portion located between the one end face of the carrier and the surface of the first case facing the second case and for mounting a predetermined member, and the second case may include a second mounting portion located between the other end face of the carrier and the surface of the second case facing the first case and for mounting another predetermined member.

[0016] The reducer according to one embodiment may further include a seal provided between the first case and the second case.

[0017] The first input portion may be a shaft member or a driven gear supported by the carrier.

[0018] In addition, a drive device according to one embodiment includes the reducer, a first motor that inputs rotation to the first input portion of the first reduction unit, and a second motor that inputs rotation to the second input portion of the second reduction unit.

[0019] Moreover, a construction machine according to one embodiment includes a working element including the above-described reduction gear. The working element may include a first part, a second part, and a third part, the reducer is held by the first part, the second part is attached to the first case, the third part is rotatably supported on the second part, and the third part may be connected to the second case via a link device.

[0020] A construction machine according to one embodiment includes the above-described reduction gear and a working element connected to the reduction gear. The working element may include one side portion attached to the first case and extending radially outward from the first case, and another side portion rotatably supported on the one side portion, and the other side portion may be connected to the second case via a link device.

[0021] According to the present invention, torque can be transmitted separately to a plurality of members while suppressing an increase in size, and it becomes easier to transmit a desired torque. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a cross-sectional view of a drive device including a reducer according to a first embodiment. [Figure 2] FIG. 10 is a cross-sectional view of a drive device including a reducer according to a second embodiment. [Figure 3] FIG. 10 is a cross-sectional view of a drive device including a reducer according to a third embodiment. [Figure 4] 1 is a diagram showing a construction machine equipped with a drive device according to a first embodiment. [Figure 5] FIG. 3 is a diagram showing another construction machine equipped with the drive device according to the first embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, each embodiment of the present invention will be described.

[0024] First Embodiment 1 shows a drive device 1 including a reducer 10 according to a first embodiment. The drive device 1 includes the reducer 10, a first motor 110, and a second motor 120.

[0025] The reducer 10 includes a carrier 11, a first case 20, a second case 30, a first reduction unit 40, and a second reduction unit 50. The first case 20 and the second case 30 are held by the carrier 11 so as to be rotatable relative to each other. The first reduction unit 40 is connected to a first motor 110. The second reduction unit 50 is connected to a second motor 120.

[0026] The first reduction gear unit 40 receives rotation from the first motor 110. The first reduction gear unit 40 reduces the speed of the input rotation and outputs it to the first case 20. As a result, the first case 20 rotates relative to the carrier 11. The second reduction gear unit 50 receives rotation from the second motor 120. The second reduction gear unit 50 reduces the speed of the input rotation and outputs it to the second case 30. As a result, the second case 30 rotates relative to the carrier 11.

[0027] Carrier 11 includes a first end surface 11A, a second end surface 11B opposite first end surface 11A, and an outer peripheral surface 11C located between first end surface 11A and second end surface 11B. Outer peripheral surface 11C includes a first support surface 11C1 having a circular cross section and a second support surface 11C2 also having a circular cross section. First bearing 12A is fitted into first support surface 11C1. Second bearing 12B is fitted into second support surface 11C2.

[0028] 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 case 20 is cylindrical or annular. The inner peripheral surface of the first case 20 is fitted into the outer ring of the first bearing 12A. This allows the first case 20 to be held rotatably relative to the carrier 11.

[0029] 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 case 30 is cylindrical or annular. The inner peripheral surface of the second case 30 is fitted into the outer ring of the second bearing 12B. This allows the second case 30 to be held rotatably relative to the carrier 11.

[0030] The first case 20 and the second case 30 are held by the carrier 11 so as to be rotatable relative to each other at different positions between both end faces (first end face 11A and second end face 11B) of the carrier 11. Specifically, the first case 20 is held at a position closer to the first end face 11A of the carrier 11 than the second case 30. The second case 30 is held at a position closer to the second end face 11B of the carrier 11 than the first case 20.

[0031] 1, symbol C1 indicates a first rotation axis of the first case 20 relative to the carrier 11. Symbol C2 indicates a second rotation axis of the second case 30 relative to the carrier 11. The first rotation axis C1 passes through the centers of the first support surface 11C1 and the first bearing 12A. The second rotation axis C2 passes through the centers of the second support surface 11C2 and the second bearing 12B.

[0032] The first rotation axis C1 of the first case 20 and the second rotation axis C2 of the second case 30 are positioned on the same straight line. That is, the first case 20 and the second case 30 are positioned coaxially. However, although the first rotation axis C1 of the first case 20 and the second rotation axis C2 of the second case 30 are parallel to each other, they may be offset from each other. Furthermore, the first rotation axis C1 of the first case 20 and the second rotation axis C2 of the second case 30 may intersect.

[0033] In this specification, the first end face 11A refers to the surface of the carrier 11 facing away from the second case 30 in the axial direction of the first case 20 along which the first rotation axis C1 extends, and refers to the surface facing the outside of the carrier 11. The second end face 11B refers to the surface of the carrier 11 facing away from the first case 20 in the axial direction of the second case 30 along which the second rotation axis C2 extends, and refers to the surface facing the outside of the carrier 11.

[0034] In this specification, the side of the carrier 11 facing the first end face 11A is referred to as the first side FS, and the side of the carrier 11 facing the second end face 11B is referred to as the second side SS, as terms used to describe the positions of the carrier 11.

[0035] First end face 11A in the present embodiment includes portions that are offset from each other in the axial direction of first case 20, and these two portions are connected by a connecting surface that extends in the axial direction of first case 20, for example. Second end face 11B also has a shape similar to that of first end face 11A. However, first end face 11A and second end face 11B may each be surfaces that extend in the same plane.

[0036] The carrier 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 located between the first end plate 13 and the second end plate 14, a first pillar portion 15B extending from the base portion 15A toward the first end plate 13, and a second pillar portion 15C extending from the base portion 15A toward the second end plate 14. In this embodiment, the base portion 15A, the first pillar portion 15B, and the second pillar portion 15C are formed as a single member. That is, the base portion 15A, the first pillar portion 15B, and the second pillar portion 15C are configured as a seamless, one-piece part. The base portion 15A, the first pillar portion 15B, and the second pillar portion 15C may be integrally formed, for example, by casting.

[0037] The first end plate 13, the second end plate 14, and the base portion 15A of the connecting portion 15 are each generally cylindrical or annular. However, depending on the specifications, particularly the specifications of the first reduction gear unit 40 and the second reduction gear unit 50, the first end plate 13, the second end plate 14, and the base portion 15A may be solid columnar or disk-shaped.

[0038] The first end plate 13 includes a first end surface 11A. The second end plate 14 includes a second end surface 11B. A first support surface 11C1 of the carrier 11 that supports the first case 20 described above is formed across the first end plate 13 and the base portion 15A of the connecting portion 15. A second support surface 11C2 of the carrier 11 that supports the second case 30 described above is formed across the second end plate 14 and the base portion 15A of the connecting portion 15.

[0039] The first support surface 11C1 includes an outer support surface 131 of the first end plate 13 and an inner support surface 15A1 of the base portion 15A. Two first bearings 12A as described above are provided. One of the two first bearings 12A is fitted into the outer support surface 131, and the other is fitted into the inner support surface 15A1. The second support surface 11C2 of the carrier 11 includes an outer support surface 141 of the second end plate 14 and an inner support surface 15A2 of the base portion 15A. Two second bearings 12B as described above are provided. One of the two second bearings 12B is fitted into the outer support surface 141, and the other is fitted into the inner support surface 15A2.

[0040] The first end plate 13 has 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 carrier 11. The first motor mounting portion 132 is formed on an outer peripheral portion of the first end surface 11A. The first motor mounting portion 132 may be a portion having a hole that receives a fastening member that passes through a portion of the first motor 110. The second end plate 14 has a second motor mounting portion 142. The second motor mounting portion 142 connects the second motor 120 to the carrier 11. The second motor mounting portion 142 has a similar configuration to the first motor mounting portion 132, except for the position where it is formed.

[0041] The connecting portion 15 is inserted from the first end face 11A of the first end plate 13 and connected to the first end plate 13 by a fastening member that straddles the first end plate 13 and the first pillar portion 15B. The connecting portion 15 is inserted from the second end face 11B of the second end plate 14 and connected to the second end plate 14 by a fastening member that straddles the second end plate 14 and the second pillar portion 15C.

[0042] The connecting portion 15 includes a plurality of first pillar portions 15B and a plurality of second pillar portions 15C. The plurality of first pillar portions 15B are arranged at intervals in the circumferential direction of the base portion 15A on a surface of the base portion 15A facing the first end plate 13. The plurality of second pillar portions 15C are arranged at intervals in the circumferential direction of the base portion 15A on a surface of the base portion 15A facing the second end plate 14. Any of the plurality of first pillar portions 15B is aligned in a straight line with any of the plurality of second pillar portions 15C.

[0043] An inner crankshaft support hole 15A3 penetrating the base portion 15A is provided in a position where the pillar portions 15B, 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.

[0044] The inner crankshaft support hole 15A3 and the first outer crankshaft support hole 133 rotatably support, via bearings, a first crankshaft 43 (described later) that constitutes the first reduction gear unit 40 and is inserted into the inner crankshaft support hole 15A3 and the second outer crankshaft support hole 143 rotatably support, via bearings, a second crankshaft 53 (described later) that constitutes the second reduction gear unit 50 and is inserted into the inner crankshaft support hole 15A3 and the second outer crankshaft support hole 143

[0045] As described above, the first end plate 13, the second end plate 14, and the base portion 15A of the connecting portion 15 are each generally 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 that rotatably supports, via a bearing, a first center shaft 41 (described below) that constitutes the first reduction gear section 40. The inner circumferential surface of the second end plate 14 and the inner circumferential surface of the base portion 15A form a support hole that rotatably supports, via a bearing, a second center shaft 51 (described below) that constitutes the second reduction gear section 50.

[0046] 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 rotational axis C1 and the second rotational axis C2. The center lines of the inner circumferential surfaces of the first end plate 13, the base portion 15A, and the second end plate 14 are also parallel to the first rotational axis C1 and the second rotational axis C2.

[0047] The first case 20 is cylindrical. The first case 20 is held rotatably relative to the first support surface 11C1 on the outer peripheral surface 11C of the carrier 11. In this state, the first case 20 surrounds a portion of the outer peripheral surface 11C of the carrier 11. In this embodiment, the first case 20 is located between the first end surface 11A and the second end surface 11B of the carrier 11. That is, the first case 20 does not protrude from the first end surface 11A of the carrier 11 toward the first side FS. The first case 20 does not protrude from the second end surface 11B of the carrier 11 toward the second side SS. Furthermore, the first case 20 does not overlap with the second case 30 in the radial direction of the second case 30. That is, the first case 20 does not face any portion of the second case 30 in the radial direction of the second case 30.

[0048] The first case 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 can fix and hold, for example, an arm member, a link member, etc. The first mounting portion 21 is provided on the outer circumferential portion of the first case 20. The first mounting portion 21 is located between the first end face 11A of the carrier 11 and the surface of the first case 20 facing the second case 30. In other words, the first mounting portion 21 does not protrude from the first end face 11A of the carrier 11 toward the first side FS. The first mounting portion 21 does not overlap with the second case 30 in the radial direction of the second case 30. In other words, the first mounting portion 21 does not face any part of the second case 30 in the radial direction of the second case 30.

[0049] The second case 30 is also cylindrical. The second case 30 is held rotatably relative to the second support surface 11C2 on the outer peripheral surface 11C of the carrier 11 described above. In this state, the second case 30 surrounds a portion of the outer peripheral surface 11C of the carrier 11. More specifically, the second case 30 surrounds a portion of the outer peripheral surface 11C of the carrier 11 that is different from the portion of the outer peripheral surface 11C surrounded by the first case 20.

[0050] In this embodiment, the second case 30 is located between the first end face 11A and the second end face 11B of the carrier 11. That is, the second case 30 does not protrude from the second end face 11B of the carrier 11 toward the second side SS. The second case 30 does not protrude from the first end face 11A of the carrier 11 toward the first side FD. Furthermore, the second case 30 does not overlap with the first case 20 in the radial direction of the first case 20. That is, the second case 30 does not face any part of the first case 20 in the radial direction of the first case 20.

[0051] The second case 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 can fix and hold, for example, an arm member, a link member, etc. The second mounting portion 31 is provided on the outer circumferential portion of the second case 30. The second mounting portion 31 is located between the second end face 11B of the carrier 11 and the surface of the second case 30 facing the first case 20. In other words, the second mounting portion 31 does not protrude from the second end face 11B of the carrier 11 toward the second side SS. The second mounting portion 31 does not overlap with the first case 20 in the radial direction of the first case 20. In other words, the second mounting portion 31 does not face any part of the first case 20 in the radial direction of the first case 20.

[0052] A seal 60 is provided between the first case 20 and the second case 30. The seal 60 is sandwiched between the opposing surfaces of the first case 20 and the second case 30. Specifically, the end face of the first case 20 facing the second case 30 and the end face of the second case 30 facing the first case 20 face each other. A first groove 22 extending over the entire circumferential area of the first case 20 is formed in the end face of the first case 20 facing the second case 30. A second groove 32 extending over the entire circumferential area of the second case 30 is formed in the end face of the second case 30 facing the first case 20. The seal 60 is partially housed in the first groove 22 and partially housed in the second groove 32. As a result, the seal 60 is held between the first case 20 and the second case 30, spanning both the first groove 22 and the second groove 32.

[0053] The seal 60 is generally annular. The seal 60 may be configured as a floating seal, as shown in FIG. 1 . In this case, the seal 60 includes a pair of seal rings and a pair of O-rings. One of the pair of seal rings and one of the pair of O-rings are housed in the first groove 22, and the other of the pair of seal rings and the other of the pair of O-rings are housed in the second groove 32. The seal rings are wedge-shaped. The seal ring housed in the first groove 22 is arranged with its inclined surface facing 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 seal ring. The seal ring and O-ring housed in the second groove 32 are also arranged in the same manner as on the first groove 22 side. The seal ring housed in the first groove 22 and the seal ring housed in the second groove 32 abut against each other. The seal 60 is not particularly limited as long as it allows the first case 20 and the second case 30 to rotate independently.

[0054] The reducer 10 is configured as an eccentric oscillating reducer, for example, and therefore the first reduction section 40 and the second reduction section 50 each include an eccentric oscillating gear.

[0055] The first reduction gear 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 which is an eccentric oscillating gear.

[0056] The first center shaft 41 is rotatably held via bearings on the inner circumferential surface of the first end plate 13 and the inner circumferential surface of the base portion 15A. The first center shaft 41 extends from the first end face 11A of the carrier 11 to the first side FS. A first input gear 42 is provided on the portion of the first center shaft 41 that extends from the first end face 11A.

[0057] The first crankshaft 43 is rotatably held via bearings 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. The first crankshaft 43 extends from the first end face 11A of the carrier 11 to the first side FS. A first relay gear 44 is provided on the 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 on 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 on the inner circumferential surface of the first case 20.

[0058] In this embodiment, the first center shaft 41 is connected to the first motor 110. The first center shaft 41 corresponds to a first input portion of the present invention, which is held by the carrier 11 and receives rotation from the first side FS.

[0059] The second reduction gear unit 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 which is an eccentric oscillating gear. Of these, the second center shaft 51 is connected to the second motor 120. The second center shaft 51 corresponds to the second input unit of the present invention, which is held by the carrier 11 and receives rotation from the second side SS. The components of the second reduction gear unit 50 are the same as the components (41 to 45) of the first reduction gear unit 40. The components of the second reduction gear unit 50 are arranged and held in the same manner as the components of the first reduction gear unit 40, except that their positions are different. Therefore, a detailed description of the components of the second reduction gear unit 50 will be omitted.

[0060] Although the reducer 10 according to this embodiment is an eccentric oscillating reducer in which the crankshaft is offset from the center of rotation of the case, the reducer 10 may also be configured as a center-crank eccentric oscillating reducer. The reducer 10 may also be configured as a planetary gear reducer. In this case, the first reduction unit 40 may include, for example, a planetary gear that rotates on its own axis due to rotation input to a first input unit formed by a shaft member that rotates integrally with the sun gear. The planetary gear revolves around the first rotation axis C1 of the first case 20 while rotating on its own axis, and meshes with an internal gear provided on the inner circumferential surface of the first case 20.

[0061] The first motor 110 is an electric motor. The first motor 110 includes a stator 111, a rotor 112, and a rotating shaft 113 attached to the rotor 112. The first motor 110 is attached to a first motor attachment portion 132 on the carrier 11. The rotor 112 and the rotating shaft 113 are disposed inside the cylindrical stator 111. The rotor 112 and the rotating shaft 113 rotate integrally with the stator 111. The rotating shaft 113 is provided with a hole 114 extending axially from its end face. A portion of the outer circumferential surface of the first center shaft 41, which is an axial member, is fitted into the hole 114. The hole 114 and the first center shaft 41 are connected so as not to rotate relative to each other. As a result, the first center shaft 41 rotates as the first motor 110 rotates.

[0062] 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 attached to the rotor 122. The second motor 120 is attached to a second motor attachment portion 142 on the carrier 11. The rotor 122 and the rotating shaft 123 are disposed inside the cylindrical stator 121. The rotor 122 and the rotating shaft 123 rotate integrally with the stator 121. The rotating shaft 123 is provided with a hole 124 extending axially from its end face. A portion of the outer circumferential surface of the second center shaft 51, which is an axial member, is fitted into the hole 124. The hole 124 and the second center shaft 51 are connected so as not to rotate relative to each other. As a result, the second center shaft 51 rotates as the second motor 120 rotates.

[0063] An example of the operation of the driving device 1 according to this embodiment will be described.

[0064] For example, the carrier 11 is fixed to another member by the first end plate 13 and the second end plate 14. In this state, when the rotating shaft 113 of the first motor 110 rotates, the rotation is input to the first center shaft 41. The rotation input to the first center shaft 41 is then transmitted to the first crankshaft 43 via the first input gear 42 and the first relay gear 44, causing the first crankshaft 43 to rotate. The first crankshaft 43 then oscillates and rotates the first external gear 45. The rotation, which is slower than the rotation input from the first external gear 45, is then output to the first case 20 from the first external gear 45. As a result, the first case 20 rotates relative to the carrier 11.

[0065] Furthermore, when the rotating shaft 123 of the second motor 120 rotates, the rotation is input to the second center shaft 51. The rotation input to the second center shaft 51 is then transmitted to the second crankshaft 53 via the second input gear 52 and the second relay gear 54, causing the second crankshaft 53 to rotate. The second crankshaft 53 then oscillates and rotates the second external gear 55. The second external gear 55 then outputs rotation, which is slower than the rotation input, to the second case 30. This causes the second case 30 to rotate relative to the carrier 11.

[0066] In the present embodiment described above, the first case 20 and the second case 30 are held on the outer peripheral surface 11C of the common carrier 11. This reduces the area occupied by the reducer 10 compared to when dedicated carriers are provided for the first case 20 and the second case 30. The first reduction unit 40 and the second reduction unit 50 allow the first case 20 and the second case 30 to rotate separately relative to the carrier 11, thereby allowing torque to be transmitted separately from the first case 20 and the second case 30 to different members. The first center shaft 41, which corresponds to the first input section to which rotation is input from the outside of the first reduction unit 40, and the second center shaft 51, which corresponds to the second input section to which rotation is input from the outside of the second reduction unit 50, are disposed so as to be dispersed on the carrier 11. This eliminates significant restrictions on the size of, for example, the first motor 110 connected to the first center shaft 41 and the second motor 120 connected to the second center shaft 51. Therefore, the reducer 10 can be connected to, for example, a large-sized first motor 110 and a large-sized second motor 120 that can ensure a large output. Therefore, torque can be transmitted separately to multiple members while preventing an increase in size, and it becomes easier to transmit the desired torque.

[0067] Furthermore, the first rotation axis C1 of the first case 20 relative to the carrier 11 and the second rotation axis C2 of the second case 30 relative to the carrier 11 are positioned on the same straight line. In this case, the first case 20 and the second case 30 can be held by the carrier 11 while preventing the shape of the carrier 11 from becoming complicated. Furthermore, the first case 20 is positioned between both end faces of the carrier 11, and the second case 30 is positioned between both end faces of the carrier 11. This prevents the reducer 10 from becoming larger.

[0068] The first case 20 includes a first mounting portion 21 located between the first end surface 11A of the carrier 11 and the surface of the first case 20 facing the second case 30, and for mounting a predetermined member. The second case 30 includes a second mounting portion 31 located between the second end surface 11B of the carrier 11 and the surface of the second case 30 facing the first case 20, and for mounting another predetermined member. With this configuration, when a predetermined member is mounted to the first mounting portion 21 and another predetermined member is mounted to the second mounting portion 31, unevenness in the load applied to the first reduction unit 40 and the second reduction unit 50 is suppressed. This can improve the durability of the reducer 10.

[0069] Furthermore, a seal 60 is provided between the first case 20 and the second case 30. This configuration can prevent fluids such as hydraulic oil and rain, and foreign matter such as dirt from passing through the gap between the first case 20 and the second case 30. Furthermore, by sharing the seal 60 between the first case 20 and the second case 30, the number of seals can be reduced.

[0070] <Second embodiment> Next, a drive device 2 equipped with a reducer 10' according to a second embodiment will be described with reference to FIG. 2. Components in this embodiment that are the same as those in the first embodiment are given the same reference numerals, and duplicated explanations will be omitted. In the second embodiment, the configuration of the carrier 11 in the reducer 10' differs from that in the first embodiment.

[0071] In this embodiment, a parting line Pl extending radially of base portion 15A is formed on base portion 15A of connecting portion 15. Carrier 11 includes first and second carrier halves 11L and 11R that are separably connected at parting line PL. First carrier half 11L includes a first end surface 11A. Second carrier half 11R includes a second end surface 11B.

[0072] Specifically, the base portion 15A of the connecting portion 15 includes a first side portion 151 and a second side portion 152 separated by a parting line PL. A first pillar portion 15B is integrated with the first side portion 151. A second pillar portion 15C is integrated with the second side portion 152. The first carrier half 11L includes the first side portion 151, the first pillar portion 15B, and the first end plate 13. The second carrier half 11R includes the second side portion 152, the second pillar portion 15C, and the second end plate 14. The parting line PL is set at a position that does not intersect with the first reduction gear unit 40 and the second reduction gear unit 50. The first carrier half 11L holds the first reduction gear unit 40. The second carrier half 11R holds the second reduction gear unit 50.

[0073] In this embodiment, first carrier half 11L and second carrier half 11R are connected by fastening members that are inserted from second end face 11B into second pillar portion 15C, second side portion 152, and first side portion 151. However, first carrier half 11L and second carrier half 11R may also be connected by fastening members that are inserted from first end face 11A.

[0074] In this embodiment, the carrier 11 includes an exposed portion 11E that is exposed between the first case 20 and the second case 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 portions of the first side portion 151 and the second side portion 152 that constitute the exposed portion 11E are located between the end faces of the first case 20 and the second case 30, which face each other. A first side seal 61 is provided between the outer peripheral portion of the first side portion 151 and the end face of the first case 20. A second side seal 62 is provided between the outer peripheral portion of the second side portion 152 and the end face of the second case 30. The first side seal 61 and the second side seal 62 may be floating seals as shown in the figure, but the type thereof is not particularly limited.

[0075] In the second embodiment, the carrier 11 includes a first carrier half 11L that holds the first reduction gear unit 40 and a second carrier half 11R that holds the second reduction gear unit 50, which are separably connected. This configuration facilitates assembly and disassembly, for example. Furthermore, an exposed portion 11E, which is a part of the carrier 11, is exposed between the first case 20 and the second case 30. This configuration allows the exposed portion 11E to be used as a support point for the reducer 10′, improving stability when supporting the reducer 10′.

[0076] <Third embodiment> Next, a driving device 3 including a reducer 10'' according to a third embodiment will be described with reference to FIG. 3. Components in this embodiment that are the same as those in the first and second embodiments are given the same reference numerals, and duplicated explanations will be omitted. In the third embodiment, the configuration of the carrier 11 in the reducer 10'' differs from that in the first and second embodiments.

[0077] Similar to the second embodiment, the carrier 11 in this embodiment includes a first carrier half 11L and a second carrier half 11R that are separably connected at the parting line PL. However, this embodiment differs from the second embodiment in that an exposed portion 11E of the carrier 11 protrudes from the first case 20 and the second case 30.

[0078] Specifically, the first carrier half 11L includes a first flange portion 161 extending from between the first case 20 and the second case 30 radially outward relative to the first case 20 and radially outward relative to the second case 30. The first flange portion 161 is formed on the first side portion 151. The second carrier half 11R includes a second flange portion 162 extending from between the first case 20 and the second case 30 radially outward relative to the first case 20 and radially outward relative to the second case 30. The second flange portion 162 is formed on the second side portion 152. Here, "outer in the radial direction" refers to the side away from the center in the radial direction. "Inner in the radial direction" refers to the side closer to the center in the radial direction.

[0079] In the present embodiment, first flange portion 161 and second flange portion 162 constitute exposed portion 11E. First carrier half 11L and second carrier half 11R are connected by a fastening member that spans first flange portion 161 and second flange portion 162. The fastening member is passed through a position radially outward from the outer circumferential surface of first case 20 and a position radially outward from the outer circumferential surface of second case 30.

[0080] In the third embodiment, the positions for fastening the first carrier half 11L and the second carrier half 11R can be located on the outer peripheries of the first reduction gear section 40 and the second reduction gear section 50. This makes it easy to create a structure in which, for example, the members constituting the first reduction gear section 40 are assembled into the first carrier half 11L, and the members constituting the second reduction gear section 50 are assembled into the second carrier half 11R, and then the first carrier half 11L and the second carrier half 11R can be connected. This makes it easy to assemble the reducer 10''. In addition, the first flange portion 161 and the second flange portion 162 can be used as support points for the reducer 10'', improving stability when supporting the reducer 10''.

[0081] <Construction machinery (1)> Fig. 4 is a diagram showing a construction machine M1 equipped with a drive unit 1 according to the first embodiment. The construction machine M1 shown in Fig. 4 is a shovel. The construction machine M1 is equipped with a working element 200 connected to a construction machine main body (not shown). The construction machine M1 may also be equipped with a drive unit 2 according to the second embodiment or a drive unit 3 according to the third embodiment.

[0082] The work element 200 includes a boom 201, an arm 202, and a bucket 203. A base end portion of the boom 201 is rotatably connected to the construction machine body. A base end portion of the arm 202 is connected to a tip end portion of the boom 201. A base end portion of the bucket 203 is connected to a tip end portion of the arm 202.

[0083] In the construction machine M1, a drive unit 1 is attached to the tip portion of a boom 201. In this embodiment, the boom 201 includes, as an example, a pair of side plates that face each other and extend in the longitudinal direction of the boom 201, and a connecting plate that connects the pair of side plates. Then, with reference to FIG. 1 , a tip portion of one of the pair of side plates supports a first end plate 13 of a carrier 11, and a tip portion of the other of the pair of side plates supports a second end plate 14 of the carrier 11.

[0084] In the construction machine M1, a base end portion of an arm 202 is connected to the first case 20. As a result, the arm 202 rotates around the connection point with the boom 201 in response to the rotation of the first case 20. The bucket 203 is rotatably connected to the tip end portion of the arm 202 via a bearing or the like. The bucket 203 is connected to the second case 30 via a first link device 210. In the example shown, the first link device 210 is pushed and pulled in response to the rotation of the second case 30, causing the bucket 203 to rotate around the connection point with the arm 202. In the example shown, the first link device 210 is formed by connecting three links in series. One link is rotatably connected to one end of the central link, and the other link is rotatably connected to the other end of the central link. That is, in the construction machine M1, the work element 200 includes a reducer 10.

[0085] In the construction machine M1, the first case 20 and the second case 30 are held on the outer peripheral surface 11C of the common carrier 11 in the reducer 10 of the drive unit 1, which is disposed at the connection between the boom 201 and the arm 202. This reduces the area occupied by the reducer 10 and the drive unit 1. As a result, the amount of overhang of the drive unit 1 from the boom 201 and the arm 202 is reduced. This reduces the risk of the drive unit 1 coming into contact with the ground or a structure that is the work target, and reduces the risk of the drive unit 1 being damaged.

[0086] Moreover, as an example, the boom 201 includes a pair of side plates that face each other and extend in the longitudinal direction of the boom 201, with a tip end portion of one of the pair of side plates supporting a first end plate 13 of the carrier 11 and a tip end portion of the other of the pair of side plates supporting a second end plate 14 of the carrier 11. In this case, the reducer 10, which is a heavy object, is supported by the boom 201 in a double-supported state. This improves the stability of the support state of the reducer 10 and the driving device 1. Note that in the example of FIG. 4 , the first portion, the second portion, and the third portion of the present invention correspond to the boom 201, the arm 202, and the bucket 203, respectively.

[0087] <Construction machinery (2)> FIG. 5 is a diagram showing a construction machine M2 equipped with a drive unit 1 according to the first embodiment. The construction machine M2 shown in FIG. 5 is a shovel. In the construction machine M2, the drive unit 1 is attached to a construction machine main body (not shown). A base end portion of a boom 201 is connected to a first case 20. As a result, the boom 201 rotates around the connection point with the construction machine main body in response to rotation of the first case 20. In addition, an arm 202 is rotatably connected to a tip end portion of the boom 201 via a bearing or the like. The arm 202 is connected to a second case 30 via a second link device 220. In the example shown in the figure, the arm 202 rotates by pushing and pulling the second link device 220 in response to rotation of the second case 30. In addition, in the construction machine M2, another drive unit arranged at the connection position between the boom 201 and the arm 202 is connected to a bucket 203 by the first link device 210 shown in FIG. 4.

[0088] The construction machine M2 can achieve the same effects as the construction machine M1 described in Fig. 4. In the example of Fig. 5, one side portion corresponds to the boom 201 and the other side portion corresponds to the arm 202 in the present invention.

[0089] The aspects of the present invention are not limited to the individual embodiments described above, but include various modifications that may be conceived by those skilled in the art, and the effects of the present invention are not limited to the above. In other words, various additions, modifications, and partial deletions are possible within the scope of the conceptual idea and spirit of the present invention as derived from the content defined in the claims and their equivalents. Among the embodiments disclosed in this specification, those consisting of multiple objects may be integrated, and conversely, a single object may be divided into multiple objects. Regardless of whether they are integrated, it is sufficient that the object of the invention can be achieved.

[0090] For example, in the embodiment described above, a portion of the outer peripheral surface of the first center shaft 41 is fitted into a hole 114 formed in the rotating shaft 113 of the first motor 110. The hole 114 and the first center shaft 41 are connected so as not to rotate relative to each other. Alternatively, a hole extending axially from the end face of the first center shaft 41 may be formed, and the rotating shaft 113 may be inserted into this hole. In this case as well, the first center shaft 41 corresponds to the first input portion.

[0091] Furthermore, the first reduction unit 40 in the reducer 10 does not have to include the first center shaft 41 and the first input gear 42. In this case, a drive gear provided on the rotating shaft 113 of the first motor 110 may be meshed with the first relay gear 44 to transmit rotation. In this case, the first relay gear 44, which is the driven gear, corresponds to the first input unit. [Explanation of symbols]

[0092] 1,2,3...Driver, 10,10',10''...Reduction gear, 11...Carrier, 11A...First end face, 11B...Second end face, 11C...Outer peripheral surface, 11C1...First support surface, 11C2...Second support surface, 11L...First carrier half, 11R...Second carrier 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 support surface, 142...second motor mounting portion, 143...second outer crankshaft support hole, 15...connecting portion, 15A...base portion, 15A1, 15A2...inner support surface, 15A3...inner crankshaft support hole, 15B...first pillar portion, 15C...second pillar portion, 151...first side portion, 152...second side portion, 161...first flange portion, 162...second flange portion, 20...first case, 21...first mounting portion, 21A...fastening hole, 22...second No. 1 groove, 30...second case, 31...second mounting portion, 31A...fastening hole, 32...second groove, 40...first reduction portion, 41...first center shaft, 42...first input gear, 43...first crankshaft, 44...first intermediate gear, 45...first external gear, 50...second reduction portion, 51...second center shaft, 52...second input gear, 53...second crankshaft, 54...second intermediate gear, 55...second external gear, 60...seal, 61...first side seal, 62...second side 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 rotation axis, C2...second rotation axis, FS...first side, SS...second side, M1, M2...construction machine, 200...working element, 201...boom, 202...arm, 203...bucket, 210...first link device, 220...second link device

Claims

1. Career and a first case that surrounds an outer peripheral surface of the carrier between both end surfaces of the carrier and is held rotatably relative to the carrier between the both end surfaces of the carrier; a second case that surrounds the outer peripheral surface of the carrier and is held by the carrier so as to be rotatable relative to the carrier at a position different from a holding position of the first case between the end faces of the carrier; a first reduction section including a first input section that is held by the carrier and receives rotation from a first side that faces one of the end faces of the carrier, the first reduction section reducing the speed of the rotation input to the first input section and outputting the reduced speed to the first case; a second reduction section including a second input section that is held by the carrier and receives rotation from a second side that faces the other of the end faces of the carrier, and that reduces the speed of the rotation input to the second input section and outputs the reduced speed to the second case, the first reduction gear unit includes a first external gear that is an eccentric oscillating gear, the second reduction gear unit includes a second external gear that is an eccentric oscillating gear, the carrier includes a first end plate, a second end plate, and a connecting portion connecting the first end plate and the second end plate; the connecting portion includes a base portion located between the first end plate and the second end plate, a first pillar portion extending from the base portion toward the first end plate, and a second pillar portion extending from the base portion toward the second end plate, the first external gear is located between the first end plate and the base portion of the connecting portion and penetrates the first post portion; the second external gear is located between the second end plate and the base portion of the connecting part and penetrates the second pillar portion.

2. The reducer according to claim 1 , wherein a first rotation axis of the first case relative to the carrier and a second rotation axis of the second case relative to the carrier are positioned on the same straight line.

3. the first case is located between the two end surfaces of the carrier; The reducer according to claim 1 , wherein the second case is located between the two end surfaces of the carrier.

4. The reducer according to claim 1 , wherein the carrier includes a first carrier half that holds the first reduction unit and a second carrier half that holds the second reduction unit, the first carrier half and the second carrier half being separably connected to each other.

5. A carrier; a first case that surrounds an outer peripheral surface of the carrier between both end surfaces of the carrier and is held rotatably relative to the carrier between the both end surfaces of the carrier; a second case that surrounds the outer peripheral surface of the carrier and is held by the carrier so as to be rotatable relative to the carrier at a position different from a holding position of the first case between the end faces of the carrier; a first reduction section including a first input section that is held by the carrier and receives rotation from a first side that faces one of the end faces of the carrier, the first reduction section reducing the speed of the rotation input to the first input section and outputting the reduced speed to the first case; a second reduction section including a second input section that is held by the carrier and receives rotation from a second side that faces the other of the end faces of the carrier, and that reduces the speed of the rotation input to the second input section and outputs the reduced speed to the second case, the carrier includes a first carrier half that holds the first reduction gear unit and a second carrier half that holds the second reduction gear unit, the first carrier half and the second carrier half being separably connected to each other; the first carrier half includes a first flange portion extending from between the first case and the second case radially outward relative to the first case and radially outward relative to the second case, the second carrier half includes a second flange portion extending from between the first case and the second case radially outward relative to the first case and radially outward relative to the second case, The first carrier half and the second carrier half are connected by a fastening member that straddles the first flange portion and the second flange portion.

6. The reducer according to claim 1 , wherein a portion of the carrier is exposed between the first case and the second case.

7. A carrier; a first case that surrounds an outer peripheral surface of the carrier between both end surfaces of the carrier and is held rotatably relative to the carrier between the both end surfaces of the carrier; a second case that surrounds the outer peripheral surface of the carrier and is held by the carrier so as to be rotatable relative to the carrier at a position different from a holding position of the first case between the end faces of the carrier; a first reduction section including a first input section that is held by the carrier and receives rotation from a first side that faces one of the end faces of the carrier, the first reduction section reducing the speed of the rotation input to the first input section and outputting the reduced speed to the first case; a second reduction section including a second input section that is held by the carrier and receives rotation from a second side that faces the other of the end faces of the carrier, and that reduces the speed of the rotation input to the second input section and outputs the reduced speed to the second case, the carrier includes a first carrier half that holds the first reduction gear unit and a second carrier half that holds the second reduction gear unit, the first carrier half and the second carrier half being separably connected to each other; the first case includes a first mounting portion located between the one end surface of the carrier and a surface of the first case facing the second case, the first mounting portion being adapted to mount a predetermined member; The second case includes a second mounting portion located between the other end face of the carrier and the surface of the second case facing the first case, and for mounting another specified member.

8. The reducer according to claim 1 , further comprising a seal provided between the first case and the second case.

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

10. A reducer according to any one of claims 1 to 9; a first motor that inputs rotation to the first input portion of the first reduction gear unit; a second motor that inputs rotation to the second input portion of the second reduction gear portion.

11. A construction machine comprising a working element including the reducer according to claim 1.

12. A working element including a reducer, the reducer includes: a carrier; a first case surrounding an outer peripheral surface of the carrier between both end faces of the carrier and held rotatably relative to the carrier between the both end faces of the carrier; a second case surrounding the outer peripheral surface of the carrier and held rotatably relative to the carrier at a position different from a holding position of the first case between the both end faces of the carrier; a first reduction unit held by the carrier and including a first input unit that receives rotation from a first side facing one of the both end faces of the carrier, the first reduction unit reducing the rotation input to the first input unit and outputting the rotation to the first case; and a second reduction unit held by the carrier and including a second input unit that receives rotation from a second side facing the other of the both end faces of the carrier, the second reduction unit reducing the rotation input to the second input unit and outputting the rotation to the second case, the working element includes a first portion, a second portion, and a third portion; the reducer is held by the first part, the second part is attached to the first case, and the third part is rotatably supported by the second part, The third portion is connected to the second case via a link device.

13. A reducer according to any one of claims 1 to 9; a working element connected to the reducer.

14. A working element including a reducer, the reducer includes: a carrier; a first case surrounding an outer peripheral surface of the carrier between both end faces of the carrier and held rotatably relative to the carrier between the both end faces of the carrier; a second case surrounding the outer peripheral surface of the carrier and held rotatably relative to the carrier at a position different from a holding position of the first case between the both end faces of the carrier; a first reduction unit held by the carrier and including a first input unit that receives rotation from a first side facing one of the both end faces of the carrier, the first reduction unit reducing the rotation input to the first input unit and outputting the rotation to the first case; and a second reduction unit held by the carrier and including a second input unit that receives rotation from a second side facing the other of the both end faces of the carrier, the second reduction unit reducing the rotation input to the second input unit and outputting the rotation to the second case, the working element includes one side portion attached to the first case and extending radially outward from the first case, and another side portion rotatably supported by the one side portion, The other side portion is connected to the second case via a link device.

Images