Speed reducer, drive device, and construction machine

Abstract

A speed reducer (10) according to an embodiment is provided with a first speed reduction unit (100) and a second speed reduction unit (200). The first speed reduction unit (100) is provided with: a first carrier (101); a first housing (102) that surrounds the first carrier (101) and is held by the first carrier (101) so as to be rotatable relative to the first carrier (101); and a first speed reduction unit (103) that includes a first center shaft (131) that corresponds to a first input unit that is held by the first carrier (101) and that inputs rotation from the drive shaft (303). The second speed reduction unit (200) is provided with: a second carrier (201); a second housing (202) that surrounds the second carrier (201) and is held by the second carrier (201) so as to be rotatable relative to the second carrier (201); and a second reduction unit (203) that includes a second center shaft (231) that corresponds to a second input unit that is held by the second carrier (201) and that inputs rotation together with the first center shaft (131) from the drive shaft (303).

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 stick, and a bucket. When the working element is actuated by an electric motor, for example, the electric motor supported on the upper rotating body of the excavator may be connected to the base end of the boom via a reducer, the electric motor supported on the top end of the boom may be connected to the base end of the dipper stick via a reducer, and the electric motor supported on the top end of the dipper stick may be connected to the bucket via a reducer.

[0003] When the upper rotating body, boom, arm and bucket are connected as described above, the upper rotating body may support the boom by means of an electric motor and a reducer cantilever, the boom supports the arm by means of an electric motor and a reducer cantilever, and the arm supports the bucket by means of an electric motor and a reducer cantilever.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 11-343642 Summary of the invention

[0007] In the above-mentioned cantilever support connection form, the impact transmitted from the work object to each reducer when the excavator is working may become excessively large in both radial and axial directions. In addition, a large torque may be applied to each cantilever support part. Therefore, it is required to improve the rigidity and strength of the reducer. In addition, it is required to ensure sufficiently high rigidity and strength in each cantilever support part.

[0008] However, ensuring the desired rigidity and strength leads to the problem of increasing the size of the speed reducer and the cantilever support part. Therefore, there is a possibility that the construction machine will become larger and the convenience will be impaired, and the power consumption will become a great burden due to the increase in weight.

[0009] The present invention has been made in consideration of the above-mentioned actual situation, and aims to provide a speed reducer, a drive device and a construction machine which can suppress enlargement and easily ensure the desired rigidity and strength.

[0010] A reducer in one embodiment comprises: a first reduction unit, which includes: a first gear rack; a first housing, which surrounds the first gear rack and is held on the first gear rack in a manner that is relatively rotatable relative to the first gear rack; and a first reduction part, which includes a first input part that is held on the first gear rack and rotates from a drive shaft input, and the first reduction part reduces the rotation input to the first input part and outputs it to the first housing; and a second reduction unit, which includes: a second gear rack; a second housing, which surrounds the second gear rack and is held on the second gear rack in a manner that is relatively rotatable relative to the second gear rack; and a second reduction part, which includes a second input part that is held on the second gear rack and rotates from the drive shaft input together with the first input part, and the second reduction part reduces the rotation input to the second input part and outputs it to the second housing.

[0011] Alternatively, the first reduction unit and the second reduction unit may be arranged in such a manner that a first rotation axis of the first housing relative to the first gear rack and a second rotation axis of the second housing relative to the second gear rack are located on the same straight line, a space is formed between the first reduction unit and the second reduction unit, and the first input part and the second input part are exposed in the space between the first reduction unit and the second reduction unit.

[0012] Alternatively, the first input portion is a shaft member rotatably supported on the first gear frame, the second input portion is a shaft member rotatably supported on the second gear frame, and the first input portion and the second input portion are arranged in such a manner that a rotation axis of the first input portion and a rotation axis of the second input portion are located on the same straight line.

[0013] Alternatively, the first input portion is a passive gear rotatably supported on the first gear frame, the second input portion is a passive gear rotatably supported on the second gear frame, and the first input portion and the second input portion are arranged in a manner that a rotation axis of the first input portion and a rotation axis of the second input portion are located on the same straight line or are arranged in a manner that a rotation axis of the first input portion and a rotation axis of the second input portion are separated circumferentially on concentric circles of the drive shaft and separated in the axial direction of the drive shaft.

[0014] In the speed reducer according to one embodiment, the first input portion and the second input portion may be constituted by a shaft member supported in a state of straddling the first carrier and the second carrier.

[0015] In the speed reducer according to one embodiment, a speed reduction ratio of the first speed reduction portion may be the same as a speed reduction ratio of the second speed reduction portion.

[0016] In the speed reducer according to one embodiment, a speed reduction ratio of the first speed reduction portion may be different from a speed reduction ratio of the second speed reduction portion.

[0017] In addition, a driving device according to an embodiment includes: the speed reducer; and a motor including the driving shaft.

[0018] The motor may be provided between the first reduction unit and the second reduction unit.

[0019] The motor may include a stator and a rotor disposed inside the stator and connected to the drive shaft, wherein the rotor is supported by the first gear carrier and the second gear carrier via the drive shaft.

[0020] Furthermore, the first reduction unit and the second reduction unit may be provided on one side of the motor.

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

[0022] Alternatively, a construction machine according to one embodiment may include a construction machine body supporting the working element, wherein the working element includes a working element portion mounted on the first housing and the second housing, and the construction machine body supports the driving device via the first gear frame and the second gear frame.

[0023] Alternatively, the working element includes a first working element portion and a second working element portion, the first working element portion supports the driving device via the first gear frame and the second gear frame, and the second working element portion is mounted on the first shell and the second shell.

[0024] According to the present invention, it is easy to ensure desired rigidity and strength while suppressing an increase in size. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a cross-sectional view of a drive device including a speed reducer according to the first embodiment.

[0026] Figure 2 It is a cross-sectional view of a drive device including a speed reducer according to a second embodiment.

[0027] Figure 3 It is a cross-sectional view of a drive device including a speed reducer according to a third embodiment.

[0028] Figure 4 It is a side view of the construction machine provided with the driving device of the first embodiment.

[0029] Figure 5 yes Figure 4A top view of the construction machine is shown. DETAILED DESCRIPTION

[0030] Hereinafter, each embodiment of the present invention will be described.

[0031] <First embodiment>

[0032] Figure 1 The driving device 1 having the speed reducer 10 of the first embodiment is shown. The driving device 1 has a motor 300 and a speed reducer 10 including a first speed reduction unit 100 and a second speed reduction unit 200. In this embodiment, the motor 300 is provided between the first speed reduction unit 100 and the second speed reduction unit 200. In this state, the first speed reduction unit 100, the second speed reduction unit 200 and the motor 300 are integrated.

[0033] The first reduction unit 100 includes a first gear frame 101, a first housing 102, and a first reduction section 103. The first gear frame 101 is fixed to the motor 300. The first housing 102 surrounds the first gear frame 101 and is held on the first gear frame 101 in a manner that is relatively rotatable relative to the first gear frame 101. The first reduction section 103 is connected to the motor 300. The first reduction section 103 inputs rotation from the motor 300. The first reduction section 103 reduces the rotation input from the motor 300 and outputs it to the first housing 102. As a result, the first housing 102 rotates relative to the first gear frame 101.

[0034] The first gear frame 101 has one of its two end faces ( Figure 1 The first gear frame 101 is arranged so as to face the motor 300. The first gear frame 101 includes a first support surface 101C having a circular cross section on the outer peripheral surface located between the two end surfaces. The first bearing 104 is externally mounted on the first support surface 101C.

[0035] The first bearing 104 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 102 is cylindrical or annular. The inner circumferential surface of the first housing 102 is fitted over the outer ring of the first bearing 104. Thus, the first housing 102 is held on the first gear frame 101 in a relatively rotatable manner relative to the first gear frame 101.

[0036] Figure 1 The reference symbol C1 in denoted by FIG. 1 represents a first rotation axis of the first housing 102 with respect to the first carrier 101 . The first rotation axis C1 passes through the first support surface 101C and the center of the first bearing 104 .

[0037] The first gear carrier 101 includes a first inner end plate 111 , a first outer end plate 112 , and a first connecting column 113 connecting the first inner end plate 111 and the first outer end plate 112 .

[0038] The first inner end plate 111 and the first outer end plate 112 are generally cylindrical or annular, respectively. The first inner end plate 111 and the first outer end plate 112 are positioned so as to surround the first rotation axis C1. The central axis of the first inner end plate 111 and the central axis of the first outer end plate 112 coincide with the first rotation axis C1. In addition, the first inner end plate 111 and the first outer end plate 112 may also be solid cylindrical or disc-shaped according to the specifications, especially according to the specifications of the first speed reduction section 103.

[0039] The first inner end plate 111 faces the motor 300. The first inner end plate 111 includes a first fixing portion 111A fixed to the motor 300. The first fixing portion 111A is provided on the outer peripheral portion of the first inner end plate 111. The first fixing portion 111A may be a portion having a hole for receiving a fastening member inserted into a part of the motor 300.

[0040] The first outer end plate 112 is located farther from the motor 300 than the first inner end plate 111 in the axial direction in which the first rotation axis C1 of the first housing 102 extends. The first outer end plate 112 is provided with a first fastening portion 112A having a fastening hole extending from a surface facing the outside toward the first inner end plate 111. The first fastening portion 112A is used, for example, for fixing to a supporting portion that supports the drive device 1.

[0041] The first connecting column 113 extends along the first rotation axis C1 between the first inner end plate 111 and the first outer end plate 112. Furthermore, the first connecting column 113 connects the first inner end plate 111 and the first outer end plate 112. The first gear frame 101 includes a plurality of first connecting columns 113. The plurality of first connecting columns 113 are arranged at intervals around the first rotation axis C1. In addition, the first inner end plate 111 and the first outer end plate 112 support the first crankshaft 133, which will be discussed later, constituting the first speed reduction portion 103. The first inner end plate 111 and the first outer end plate 112 support the first crankshaft 133 so as not to interfere with the first connecting column 113.

[0042] In addition, as described above, the first inner end plate 111 and the first outer end plate 112 are respectively substantially cylindrical or annular. The inner circumferential surface of the first inner end plate 111 and the inner circumferential surface of the first outer end plate 112 form a support hole for rotatably supporting the first center shaft 131 to be discussed later constituting the first speed reduction section 103 by means of a bearing.

[0043] The first housing 102 is held by a first support surface 101C of the outer peripheral surface of the first gear frame 101 so as to be relatively rotatable with respect to the first gear frame 101. In this state, the first housing 102 surrounds the outer peripheral surface of the first gear frame 101. The first housing 102 is cylindrical.

[0044] The first housing 102 includes a first mounting portion 121 including a first fastening hole 121A extending parallel to the first rotation axis C1. The first mounting portion 121 can fix and hold, for example, an arm member, a link member, etc. The first mounting portion 121 is provided on the outer peripheral portion of the first housing 102.

[0045] As an example, the first reduction unit 100 is configured as an eccentric oscillating type reduction mechanism. The first reduction portion 103 includes a first center shaft 131, a first input gear 132, a first crankshaft 133, a first relay gear 134, and a first external gear 135 as an eccentric oscillating gear.

[0046] The first center shaft 131 is rotatably held by the inner circumference of the first inner end plate 111 and the inner circumference of the first outer end plate 112 via bearings. The first center shaft 131 extends from the first inner end plate 111 toward the motor 300, in other words, toward the second reduction unit 200. A first input gear 132 is provided at a portion of the first center shaft 131 extending from the first inner end plate 111.

[0047] The first crankshaft 133 is rotatably held by a bearing in a state of straddling the first inner end plate 111 and the first outer end plate 112. The first crankshaft 133 extends from the first inner end plate 111 toward the motor 300 side, in other words, toward the second reduction unit 200 side. A first relay gear 134 is provided at a portion of the first crankshaft 133 extending from the first inner end plate 111. The first relay gear 134 meshes with the first input gear 132. A first external gear 135 is provided at a portion of the first crankshaft 133 located between the first inner end plate 111 and the first outer end plate 112. The first external gear 135 meshes with an internal gear provided to the inner circumferential surface of the first housing 102.

[0048] In this embodiment, the first center shaft 131 is connected to the motor 300, specifically, to the drive shaft 303 of the motor 300 described later. The first center shaft 131 is held by the first gear frame 101 and corresponds to a first input portion in the present invention that receives rotation from the drive shaft 303.

[0049] The second reduction unit 200 includes a second gear frame 201, a second housing 202, and a second reduction section 203. The second gear frame 201 is fixed to the motor 300. The second housing 202 surrounds the second gear frame 201 and is held on the second gear frame 201 in a manner that is relatively rotatable relative to the second gear frame 201. The second reduction section 203 is connected to the motor 300. The second reduction section 203 inputs rotation from the motor 300. The second reduction section 203 reduces the rotation input from the motor 300 and outputs it to the second housing 202. As a result, the second housing 202 rotates relative to the second gear frame 201. That is, in the present embodiment, the first reduction unit 100 and the second reduction unit 200 input rotation from the common motor 300.

[0050] The second gear frame 201 has one of its two end faces ( Figure 1 The second gear frame 201 is arranged so as to face the motor 300. The second gear frame 201 includes a second support surface 201C having a circular cross section on the outer peripheral surface located between the two end surfaces. The second bearing 204 is externally mounted on the second support surface 201C.

[0051] The second bearing 204 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 202 is cylindrical or annular. The inner circumferential surface of the second housing 202 is fitted over the outer ring of the second bearing 204. Thus, the second housing 202 is held on the second gear frame 201 in a manner that allows relative rotation relative to the second gear frame 201.

[0052] Figure 1 The reference symbol C2 in the figure represents the second rotation axis of the second housing 202 relative to the second gear frame 201. The second rotation axis C2 passes through the second support surface 201C and the center of the second bearing 204. The first rotation axis C1 of the first housing 102 and the second rotation axis C2 of the second housing 202 are located on the same straight line. That is, the first housing 102 and the second housing 202 are located on the same axis.

[0053] The second gear carrier 201 includes a second inner end plate 211 , a second outer end plate 212 , and a second connecting column 213 connecting the second inner end plate 211 and the second outer end plate 212 .

[0054] The second inner end plate 211 and the second outer end plate 212 are respectively roughly cylindrical or annular. The second inner end plate 211 and the second outer end plate 212 are positioned in a manner of surrounding the second rotation axis C2. The central axis of the second inner end plate 211 and the central axis of the second outer end plate 212 coincide with the second rotation axis C2. In addition, there is a case where the second inner end plate 211 and the second outer end plate 212 can also be solid cylindrical or disc-shaped according to the specifications, especially according to the specifications of the second speed reduction part 203.

[0055] The second inner end plate 211 faces the motor 300. The second inner end plate 211 includes a second fixing portion 211A fixed to the motor 300. The second fixing portion 211A is provided on the outer peripheral portion of the second inner end plate 211. The second fixing portion 211A may be a portion having a hole for receiving a fastening member inserted into a part of the motor 300.

[0056] The second outer end plate 212 is located farther from the motor 300 than the second inner end plate 211 in the axial direction in which the second rotation axis C2 of the second housing 202 extends. The second outer end plate 212 is provided with a second fastening portion 212A having a fastening hole extending from a surface facing the outside toward the second inner end plate 211. The second fastening portion 212A is used, for example, for fixing to a supporting portion that supports the drive device 1.

[0057] The second connecting column 213 extends along the second rotation axis C2 between the second inner end plate 211 and the second outer end plate 212. Furthermore, the second connecting column 213 connects the second inner end plate 211 and the second outer end plate 212. The second gear frame 201 includes a plurality of second connecting columns 213. The plurality of second connecting columns 213 are arranged at intervals around the second rotation axis C2. In addition, the second inner end plate 211 and the second outer end plate 212 support the second crankshaft 233 constituting the second speed reduction section 203. The second inner end plate 211 and the second outer end plate 212 support the second crankshaft 233 so as not to interfere with the second connecting column 213.

[0058] As described above, the second inner end plate 211 and the second outer end plate 212 are substantially cylindrical or annular. The inner circumference of the second inner end plate 211 and the inner circumference of the second outer end plate 212 form a support hole for rotatably supporting the second center shaft 231 constituting the second speed reduction section 203 via a bearing.

[0059] The second housing 202 is held by the second support surface 201C of the outer peripheral surface of the second gear frame 201 so as to be relatively rotatable with respect to the second gear frame 201. In this state, the second housing 202 surrounds the outer peripheral surface of the second gear frame 201. The second housing 202 is also cylindrical.

[0060] The second housing 202 includes a second mounting portion 221 including a second fastening hole 221A extending parallel to the second rotation axis C2. The second mounting portion 221 can fix and hold, for example, an arm member, a link member, etc. The second mounting portion 221 is provided on the outer peripheral portion of the second housing 202.

[0061] As an example, the second reduction unit 200 is also configured as an eccentric swing type reduction mechanism. The second reduction part 203 includes a second center shaft 231, a second input gear 232, a second crankshaft 233, a second relay gear 234, and a second external gear 235 as an eccentric swing gear. The second center shaft 231 is connected to the motor 300, and more specifically, is connected to the drive shaft 303 of the motor 300 discussed later. The second center shaft 231 corresponds to the so-called second input part in the present invention, which is retained in the second gear frame 201 and inputs rotation from the drive shaft 303. The second center shaft 231 is input with rotation from the drive shaft 303 together with the first center shaft 131 in the first reduction unit 100.

[0062] The components of the second reduction unit 203 are the same as the components (131 to 135) of the first reduction unit 103. Furthermore, the components of the second reduction unit 203 are held on the second gear frame 201 in the same manner as the components of the first reduction unit 103 are held on the first gear frame 101, and therefore, a detailed description of the components of the second reduction unit 203 is omitted.

[0063] The positional relationship between the first central axis 131 and the second central axis 231 corresponding to the first input portion is described below. The first reduction unit 100 and the second reduction unit 200 in this embodiment are arranged so that the first rotation axis C1 of the first housing 102 and the second rotation axis C2 of the second housing 202 are located on the same straight line. In addition, a space is formed between the first reduction unit 100 and the second reduction unit 200.

[0064] In the present embodiment, the first center axis 131 and the second center axis 231 are exposed in the space between the first reduction unit 100 and the second reduction unit 200. When the first reduction unit 100, the second reduction unit 200, and the motor 300 are integrated as shown in the figure, the motor 300 is located in the space between the first reduction unit 100 and the second reduction unit 200.

[0065] More specifically, the first center axis 131 and the second center axis 231 are arranged so that the rotation axis of the first center axis 131 and the rotation axis of the second center axis 231 are located on the same straight line. The rotation axis of the first center axis 131 coincides with the first rotation axis C1. The rotation axis of the second center axis 231 coincides with the second rotation axis C2.

[0066] In addition, the first reduction unit 100 and the second reduction unit 200 in the present embodiment are eccentric oscillating type reduction mechanisms of the type in which the crankshaft is offset relative to the rotation center of the housing, but the first reduction unit 100 and the second reduction unit 200 can also be configured as eccentric oscillating type reduction mechanisms of the center crankshaft type. In addition, the first reduction unit 100 and the second reduction unit 200 can also be configured as planetary gear type reduction mechanisms. In this case, the first reduction part 103, for example, can also include a planetary gear that rotates due to the rotation input to the first input part composed of an axis member that rotates integrally with the sun gear. The planetary gear rotates while revolving around the first rotation axis C1 of the first housing 102, and meshes with the internal gear provided on the inner circumferential surface of the first housing 102.

[0067] In the present embodiment, the reduction ratio of the first reduction section 103 is the same as the reduction ratio of the second reduction section 203. However, the reduction ratio of the first reduction section 103 and the reduction ratio of the second reduction section 203 may be different.

[0068] The motor 300 is an electric motor. The motor 300 includes a stator 301, a rotor 302, a drive shaft 303 mounted on the rotor 302, and a housing 304. The motor 300 is mounted on the first fixing portion 111A of the first gear frame 101 and the second fixing portion 211A of the second gear frame 201 in a state of being clamped by the first fixing portion 111A of the first gear frame 101 and the second fixing portion 211A of the second gear frame 201.

[0069] The rotor 302 and the drive shaft 303 are arranged on the inner side of the cylindrical stator 301. The stator 301 is covered by a housing 304 and fixed to the inner circumferential surface of the housing 304. More precisely, the motor 300 is fixed to the first gear frame 101 and the second gear frame 201 by means of the housing 304. The housing 304 is mounted on the first fixing portion 111A in the first gear frame 101 and the second fixing portion 211A in the second gear frame 201.

[0070] The rotor 302 and the drive shaft 303 rotate integrally with respect to the stator 301. The drive shaft 303 is rotatably supported by the housing 304 via the bearing 305. Thus, the rotor 302 and the drive shaft 303 can rotate with respect to the stator 301.

[0071] The drive shaft 303 extends from the rotor 302 to both sides of the axial direction of the motor 300. The portions of the drive shaft 303 extending from the rotor 302 to both sides are rotatably supported by the housing 304 via bearings 305. In addition, a first hole 306 extending toward the other end surface is formed on one end surface of the drive shaft 303. A second hole 307 extending toward one end surface is formed on the other end surface of the drive shaft 303.

[0072] A portion of the outer peripheral surface of the first central axis 131 as an axis member is embedded in the first hole 306. Furthermore, the first hole 306 and the first central axis 131 are connected in a manner that does not rotate relative to each other. A portion of the outer peripheral surface of the second central axis 231 as an axis member is embedded in the second hole 307. Furthermore, the second hole 307 and the second central axis 231 are connected in a manner that does not rotate relative to each other. Thus, as the motor 300 rotates, the first central axis 131 and the second central axis 231 rotate.

[0073] An operation example of the drive device 1 according to the present embodiment will be described.

[0074] For example, the first gear frame 101 is fixed to the support portion of the support drive device 1 by the first fastening portion 112A in the first outer end plate 112, and the second gear frame 201 is fixed to the support portion of the support drive device 1 by the second fastening portion 212A in the second outer end plate 212. In this state, if the drive shaft 303 of the motor 300 rotates, the rotation is input to the first center shaft 131 and the second center shaft 231.

[0075] When the first center shaft 131 rotates, the first crankshaft 133 rotates via the first input gear 132 and the first relay gear 134. The first crankshaft 133 causes the first external gear 135 to swing and rotate. The first crankshaft 133 outputs a rotation that is reduced in speed relative to the rotation input from the first external gear 135 to the first housing 102. As a result, the first housing 102 rotates relative to the first gear frame 101.

[0076] In addition, when the second center shaft 231 rotates, the second crankshaft 233 is transmitted via the second input gear 232 and the second relay gear 234, and the second crankshaft 233 rotates. Furthermore, the second crankshaft 233 causes the second external gear 235 to swing and rotate. Furthermore, the rotation that is reduced in speed relative to the rotation input from the second external gear 235 is output to the second housing 202. As a result, the second housing 202 rotates relative to the second gear frame 201.

[0077] In the present embodiment, the reduction ratio of the first reduction unit 103 is the same as the reduction ratio of the second reduction unit 203. Therefore, when the same component is mounted on the first housing 102 and the second housing 202, torque can be simultaneously applied to the same component from the first housing 102 and the second housing 202. Alternatively, different components may be mounted on the first housing 102 and the second housing 202, in which case torque is applied to each component separately.

[0078] In the present embodiment described above, the reducer 10 includes a first reduction unit 100 and a second reduction unit 200. The first reduction unit 100 includes: a first gear frame 101; a first housing 102, which surrounds the first gear frame 101 and is held on the first gear frame 101 in a manner that is relatively rotatable relative to the first gear frame 101; and a first reduction section 103, which includes a first center shaft 131 corresponding to a first input section held on the first gear frame 101 and inputting rotation from a drive shaft 303, so that the rotation input to the first center shaft 131 is reduced in speed and output to the first housing 102. The second reduction unit 200 includes: a second gear frame 201; a second housing 202, which surrounds the second gear frame 201 and is held on the second gear frame 201 in a manner that is relatively rotatable relative to the second gear frame 201; and a second reduction portion 203, which includes a second center shaft 231 corresponding to a second input portion that is held on the second gear frame 201 and inputs rotation from the drive shaft 303 together with the first center shaft 131, so that the rotation input to the second center shaft 231 is reduced and output to the second housing 202.

[0079] Furthermore, the drive device 1 includes a first reduction unit 100, a second reduction unit 200, and a motor 300. The drive device 1 connects a drive shaft 303 of the motor 300 to a first center axis 131 of the first reduction unit 100 and a second center axis 231 of the second reduction unit 200, so that the motor 300, the first reduction unit 100, and the second reduction unit 200 are integrated.

[0080] In this structure, the first reduction unit 100 and the second reduction unit 200 can be operated by input from one drive shaft 303. In this case, the first reduction unit 100 and the second reduction unit 200 are connected by the drive shaft 303. Therefore, the load borne by the first reduction unit 100 and / or the second reduction unit 200 can be dispersed to the first reduction unit 100 and the second reduction unit 200. Thus, it is easy to ensure the desired rigidity and strength in the reducer 10 while suppressing the enlargement.

[0081] In addition, the first reduction unit 100 and the second reduction unit 200 are arranged in such a manner that the first rotation axis C1 of the first housing 102 relative to the first gear frame 101 and the second rotation axis C2 of the second housing 202 relative to the second gear frame 201 are located on the same straight line. In addition, a space is formed between the first reduction unit 100 and the second reduction unit 200. In addition, the first center axis 131 and the second center axis 231 are exposed in the space between the first reduction unit 100 and the second reduction unit 200.

[0082] In this structure, the first center shaft 131 and the second center shaft 231 can be connected to the drive shaft 303 arranged in the space between the first reduction unit 100 and the second reduction unit 200. Therefore, the complexity and size of the connection structure between the drive shaft 303 and the first reduction unit 100 and the second reduction unit 200 can be suppressed. In the present embodiment, the motor 300 is arranged between the first reduction unit 100 and the second reduction unit 200, and is integrated with the first reduction unit 100 and the second reduction unit 200. In addition, the first center shaft 131 of the first reduction unit 100 and the second center shaft 231 of the second reduction unit 200 input rotation from the drive shaft 303 located between the first reduction unit 100 and the second reduction unit 200. In this structure, the length of the drive shaft 303 is suppressed, and the transmission structure is also simple.

[0083] In addition, in the present embodiment, the first center shaft 131 corresponding to the first input portion is a shaft member rotatably supported on the first gear frame 101, and the second center shaft 231 corresponding to the second input portion is a shaft member rotatably supported on the second gear frame 201. Furthermore, the first center shaft 131 and the second center shaft 231 are arranged in such a manner that their respective rotation axes are located on the same straight line. In this structure, rotation can be transmitted from the drive shaft 303 to the first reduction unit 103 and the second reduction unit 203 without complicating and enlarging the structure of the drive shaft 303. Therefore, it is advantageous in suppressing the complication and enlargement of the connection structure between the drive shaft 303 and the first reduction unit 100 and the second reduction unit 200.

[0084] <Second embodiment>

[0085] Next, refer to Figure 2 , and a driving device 2 having a reducer 10' according to a second embodiment is described. The same reference numerals are given to the same components of the present embodiment as those of the first embodiment, and repeated descriptions are omitted. In the second embodiment, the bearing 305 is not provided in the motor 300, which is different from the first embodiment.

[0086] In detail, in the motor 300 of the present embodiment, the rotor 302 and the drive shaft 303 are not rotatably supported by the housing 304. Instead, the rotor 302 is supported by the first gear frame 101 and the second gear frame 201 via the drive shaft 303. In more detail, the drive shaft 303 is connected to the first center shaft 131 and the second center shaft 231 to be supported by the first center shaft 131 and the second center shaft 231. Thus, the rotor 302 is supported by the first gear frame 101 and the second gear frame 201 via the drive shaft 303.

[0087] In the second embodiment, the motor 300, in particular the housing 304, can be simplified, and the axial length of the drive shaft 303 can be reduced. In addition, the number of components such as bearings can be reduced, and the number of components can be reduced. Therefore, it is advantageous in terms of miniaturization of the drive device 2 and reduction of component costs.

[0088] <Third embodiment>

[0089] Next, refer to Figure 3 , and at the same time, a drive device 3 with a reducer 10" of a third 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 and second embodiments, and repeated descriptions are omitted. In the third embodiment, the configuration of the first reduction unit 100, the second reduction unit 200 and the motor 300 is different from that of the first and second embodiments.

[0090] Specifically, the first reduction unit 100 and the second reduction unit 200 are provided on one side of the motor 300. Furthermore, the motor 300, the first reduction unit 100, and the second reduction unit 200 are integrated.

[0091] In the reducer 10" of the present embodiment, an axis member 400 is provided which is supported in a state of straddling the first gear frame 101 and the second gear frame 201. The axis member 400 extends from the first gear frame 101 and the second gear frame 201 respectively. In addition, the portion of the axis member 400 extending from the first gear frame 101 is connected to the drive shaft 303 of the motor 300, and a first input gear 132 is provided. The portion of the axis member 400 extending from the second gear frame 201 is provided with a second input gear 232.

[0092] In the present embodiment, the shaft member 400 constitutes the first input portion in the first reduction portion 103 to which the rotation is input from the drive shaft 303, and the second input portion in the second reduction portion 203 to which the rotation is input from the drive shaft 303. In this structure, since the rotation is input to the first reduction portion 103 and the second reduction portion 203 using one shaft member 400, the number of parts can be suppressed.

[0093] <Construction machinery>

[0094] Figure 4 is a side view of a construction machine M equipped with the drive device 1 according to the first embodiment. Figure 5 It is a top view of the construction machine M. Figure 4 The construction machine M shown is an excavator. The construction machine M includes a working element 500 connected to a construction machine body MB (not shown). The construction machine M may include the drive device 2 of the second embodiment or the drive device 3 of the third embodiment.

[0095] The working element 500 includes a boom 501, an arm 502, and a bucket 503 as parts of the working element, and three drive devices 1. Hereinafter, among the three drive devices 1, the drive device between the construction machine body MB and the boom 501 is referred to as the first drive device 1A, the drive device between the boom 501 and the arm 502 is referred to as the second drive device 1B, and the drive device between the arm 502 and the bucket 503 is referred to as the third drive device 1C.

[0096] The base end side of the boom 501 is connected to the construction machine body MB by means of the first drive device 1A. The construction machine body MB has a pair of support parts 510 separated from each other. The first drive device 1A is arranged between the pair of support parts 510. One of the pair of support parts 510 fixes the first outer end plate 112 of the first gear frame 101, and the other of the pair of support parts 510 fixes the second outer end plate 212 of the second gear frame 201 (see Figure 1 ). In this state, the pair of support portions 510 supports the first drive device 1A in a state where at least the first housing 102 and the second housing 202 are separated from the construction machine body MB and rotation is allowed. That is, the construction machine body MB supports the first drive device 1A via the first gear frame 101 and the second gear frame 201.

[0097] The base end portion of the boom 501 is attached to the first housing 102 and the second housing 202. Thus, according to the rotation of the motor 300, the boom 501 rotates around the first rotation axis C1 and the second rotation axis C2 located on the same straight line.

[0098] Specifically, the boom 501 in this embodiment includes a pair of boom side plates 501S that face each other and extend in the length direction of the boom 501. The base end side portion of one of the pair of boom side plates 501S is mounted on the first housing 102, and the base end side portion of the other of the pair of boom side plates 501S is mounted on the second housing 202.

[0099] In addition, the top end side portion of the pair of boom side plates 501S clamps and supports the second drive device 1B. Specifically, the top end side portion of one of the pair of boom side plates 501S is fixed to the first outer end plate 112 of the first gear frame 101, and the top end side portion of the other of the pair of boom side plates 501S is fixed to the second outer end plate 212 of the second gear frame 201. That is, the boom 501 supports the first drive device 1A via the first gear frame 101 and the second gear frame 201.

[0100] Furthermore, the base end side portion of the boom 502 is mounted on the first housing 102 and the second housing 202 in the second drive device 1B. Thus, the boom 502 rotates around the first rotation axis C1 and the second rotation axis C2 according to the rotation of the motor 300 in the second drive device 1B. The boom 502 also includes a pair of side plates similar to the boom 501. The support state of the third drive device 1C in the top end side portion of the boom 502 is the same as the support state of the second drive device 1B, and therefore, the description thereof is omitted.

[0101] By providing the construction machine M with the drive devices 1A to 1C, it is possible to suppress the increase in size and weight while electrifying. In addition, for example, the load transmitted from the driven arm 501 to the first drive device 1A is dispersed to the first reduction unit 100 and the second reduction unit 200, so that the risk of damage to the reducer 10 can be suppressed. In addition, the drive devices 1A to 1C are arranged in a manner that does not extend from the working element 500. As a result, the risk of contact between the ground and the structure as the working object and the drive devices 1A to 1C can be suppressed, and the risk of damage to the drive devices 1A to 1C can be suppressed.

[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 131 is embedded in the first hole 306 provided in the drive shaft 303 of the motor 300. And the first hole 306 and the first center shaft 131 are connected in a non-rotatable manner. Alternatively, a hole extending in the axial direction from the end surface of the first center shaft 131 may be formed in the first center shaft 131, and the drive shaft 303 may be inserted into the hole. In this case, the first center shaft 131 also corresponds to the first input portion.

[0104] In addition, the first reduction part 103 in the speed reducer 10 may not include the first center shaft 131 and the first input gear 132. In this case, the driving gear provided to the driving shaft of the motor 300 may mesh with the first relay gear 134 to transmit the rotation. In this case, the first relay gear 134, which becomes the passive gear, corresponds to the first input part. Similarly, the second relay gear 234 in the second reduction part 203 may also constitute the second input part as a passive gear.

[0105] In the case where the so-called first input part in the present invention is configured as a passive gear (for example, the first relay gear 134) rotatably supported on the first gear frame 101, and the so-called second input part in the present invention is configured as a passive gear (for example, the second relay gear 234) rotatably supported on the second gear frame 201 as described above, the passive gear corresponding to the first input part and the passive gear corresponding to the second input part may also be arranged in a manner such that each rotation axis is located on the same straight line or in a manner such that each rotation axis is separated circumferentially on a concentric circle of the drive shaft 303 and separated in the axial direction of the drive shaft 303.

[0106] Description of Reference Numerals

[0107] 1, 2, 3, driving device; 10, 10', 10", speed reducer; 100, first speed reduction unit; 101, first gear frame; 101C, first support surface; 102, first housing; 103, first speed reduction part; 104, first bearing; 111, first inner end plate; 111A, first fixing part; 112, first outer end plate; 112A, first fastening part; 113, first connection Column; 121, first mounting portion; 121A, first fastening hole; 131, first center axis; 132, first input gear; 133, first crankshaft; 134, first relay gear; 135, first external gear; 200, second reduction unit; 201, second gear carrier; 201C, second support surface; 202, second housing; 203, second reduction unit; 204, second bearing; 211 , second inner end plate; 211A, second fixing portion; 212, second outer end plate; 212A, second fastening portion; 213, second connecting column; 221, second mounting portion; 221A, second fastening hole; 231, second center axis; 232, second input gear; 233, second crankshaft; 234, second relay gear; 235, second outer gear; 300, motor; 301, stator; 30 2. Rotor; 303. Drive shaft; 304. Housing; 305. Bearing; 306. 1st hole; 307. 2nd hole; 400. Shaft member; C1. 1st rotation axis; C2. 2nd rotation axis; M. construction machinery; MB, construction machinery body; 500. Working element; 501. Boom; 501S, boom side plate; 502. Arm; 503. Bucket; 510. Supporting part.

Claims

1. A reducer, wherein The reducer has: The first reduction unit, include: A first gear frame; a first housing, which surrounds the first gear frame and is held on the first gear frame in a manner that allows relative rotation relative to the first gear frame; and a first reduction unit, which includes a first input unit held on the first gear frame and inputting rotation from a drive shaft, the first reduction unit reduces the rotation input to the first input unit and outputs it to the first housing; and The second reduction unit includes: a second gear rack; a second housing, which surrounds the second gear rack and is held on the second gear rack in a manner that allows relative rotation with respect to the second gear rack; and a second reduction portion, which includes a second input portion that is held on the second gear rack and rotates together with the first input portion from the drive shaft input, and the second reduction portion reduces the rotation input to the second input portion and outputs it to the second housing.

2. The reducer according to claim 1, in, The first reduction unit and the second reduction unit are arranged in such a manner that a first rotation axis of the first housing relative to the first gear frame and a second rotation axis of the second housing relative to the second gear frame are located on the same straight line, and a space is formed between the first reduction unit and the second reduction unit. The first input portion and the second input portion are exposed to a space between the first reduction unit and the second reduction unit.

3. The reducer according to claim 2, in, The first input portion is a shaft member rotatably supported by the first gear frame, and the second input portion is a shaft member rotatably supported by the second gear frame. The first input part and the second input part are arranged in such a manner that a rotation axis of the first input part and a rotation axis of the second input part are located on the same straight line.

4. The reducer according to claim 2, in, The first input portion is a driven gear rotatably supported by the first gear frame, and the second input portion is a driven gear rotatably supported by the second gear frame. The first input part and the second input part are arranged in a manner that the rotation axis of the first input part and the rotation axis of the second input part are located on the same straight line or are configured in a manner that the rotation axis of the first input part and the rotation axis of the second input part are separated along the circumferential direction on the concentric circle of the drive shaft and separated in the axial direction of the drive shaft.

5. The reducer according to claim 1, in, The first input portion and the second input portion are constituted by a shaft member supported in a state of straddling the first gear carrier and the second gear carrier.

6. The reducer according to claim 1, in, The reduction ratio of the first reduction section is the same as the reduction ratio of the second reduction section.

7. The reducer according to claim 1, in, The reduction ratio of the first reduction section is different from the reduction ratio of the second reduction section.

8. A driving device, in, The drive device has: The reducer according to any one of claims 1 to 7; and A motor includes the drive shaft.

9. The driving device according to claim 8, in, The motor is provided between the first reduction unit and the second reduction unit.

10. The driving device according to claim 9, in, The motor includes: a stator; and a rotor, which is arranged inside the stator and connected to the drive shaft. The rotor is supported by the first carrier and the second carrier via the drive shaft.

11. The driving device according to claim 8, in, The first reduction unit and the second reduction unit are provided on one side of the motor.

12. A construction machine, in, The construction machine includes a working element including the drive device according to claim 8 .

13. The construction machine according to claim 12, in, The construction machine includes a construction machine body supporting the working element. The working element includes a working element portion installed on the first shell and the second shell, The construction machine body supports the driving device via the first gear frame and the second gear frame.

14. The construction machine according to claim 12, in, The working element comprises a first working element part and a second working element part, The first working element portion supports the driving device via the first gear frame and the second gear frame, and the second working element portion is mounted on the first housing and the second housing.

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