Construction machine and working machine for construction machine

Abstract

To provide a construction machine having a simple structure and a working machine for the construction machine.SOLUTION: A construction machine includes a boom 7 having a base end 7A supported by a support part 5 of a body part via a first driving part 10, an arm 8 having a base end 8A supported by the boom 7 via a second driving part 20, and an attachment 9 having a base end 9A supported by the arm 8 via a third driving part 30. The 11A of one end of the first drive shaft 11 is fixed to the 5A of the distal end portion of the support portion 5. The other end 11B of first drive shaft 11 is fixed to a base end 7A of boom 7. One end 21A of the second drive shaft 21 is fixed to a tip end 7B of the boom 7. The other end 21B of the second drive shaft 21 is fixed to the 8A of the base end portion of the arm 8. One end 31A of the third drive shaft 31 is fixed to the 8B of the distal end portion of the arm 8. The other end 31B of the third drive shaft 31 is fixed to the 9A of the base end portion of the attachment 9. Center line W7 of the widthwise P7 of boom 7 is located at a position included in the widthwise W8 of arm 8.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a construction machine and a working implement for the construction machine. [Background technology]

[0002] A construction machine such as a hydraulic excavator includes a self-propelled running body and a rotating body that is rotatably attached to the running body. The rotating body includes a driver's cab where an operator sits. The rotating body also includes an operating unit whose base end is rotatably connected. The operating unit includes a boom whose base end is rotatably connected, an arm whose base end is rotatably connected to the tip of the boom, and a bucket rotatably connected to the tip of the arm.

[0003] A hydraulic actuator with a linear motion mechanism is often provided at the connection between the rotating unit and the boom, the connection between the boom and the arm, and the connection between the arm and the bucket. The hydraulic actuator includes a cylinder and a piston rod that extends and retracts relative to the cylinder. For example, at the connection between the rotating unit and the boom, the base end of the cylinder is rotatably attached to either the rotating unit or the boom, and the tip end of the piston rod is rotatably attached to the other. Hydraulic actuators are also attached to the connection between the boom and the arm, and the connection between the arm and the bucket. The boom, arm, and bucket are rotated by extending and retracting the piston rod relative to the cylinder.

[0004] Electricalization is desirable for construction machinery from the perspective of simplifying its structure, etc. For this reason, Patent Document 1 discloses a construction machine that uses a linear-motion electric cylinder with a built-in ball screw type reduction gear instead of a hydraulic actuator. The ball screw type reduction gear is attached to the construction machine in a similar manner to a hydraulic cylinder. That is, for example, the base end of the cylinder tube is rotatably attached to either the rotating body or the boom, and the tip end of the piston is rotatably attached to the other. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-82707 Summary of the Invention [Problem to be solved by the invention]

[0006] Incidentally, in the construction machine described in Patent Document 1, it is necessary to rotatably support the cylinder and piston on the boom or the like, so a rotation mechanism is also used in addition to a linear motion mechanism. That is, in order to rotatably support the cylinder and piston on the boom or the like, a shaft, a bearing for rotatably supporting the shaft, or the like is provided as a rotation mechanism, and the cylinder and piston are rotatably connected to the boom or the like via this rotation mechanism. In this way, the combined use of a linear motion mechanism and a rotation mechanism poses the problem of making it difficult to simplify the structure of the construction machine. [Means for solving the problem]

[0007] A construction machine that solves the above problem comprises a boom whose base end is supported on a support portion of a main body via a first drive unit, an arm whose base end is supported on the boom via a second drive unit, and an attachment whose base end is supported on the arm via a third drive unit, wherein one end of a first drive shaft of the first drive unit is fixed to the tip end of the support portion and the other end of the first drive shaft is fixed to the base end of the boom, one end of a second drive shaft of the second drive unit is fixed to the tip end of the boom and the other end of the second drive shaft is fixed to the base end of the arm, one end of a third drive shaft of the third drive unit is fixed to the tip end of the arm and the other end of the third drive shaft is fixed to the base end of the attachment, and the center line of the width of the boom is located at a position included in the width of the arm.

[0008] A working implement for a construction machine that solves the above problem comprises a boom whose base end is supported on a support part of the main body of the construction machine via a first drive unit, an arm whose base end is supported on the boom via a second drive unit, and an attachment whose base end is supported on the arm via a third drive unit, wherein one end of a first drive shaft of the first drive unit is fixed to the tip end of the support part and the other end of the first drive shaft is fixed to the base end of the boom, one end of a second drive shaft of the second drive unit is fixed to the tip end of the boom and the other end of the second drive shaft is fixed to the base end of the arm, one end of a third drive shaft of the third drive unit is fixed to the tip end of the arm and the other end of the third drive shaft is fixed to the base end of the attachment, and the center line of the width of the boom is located at a position included in the width of the arm.

[0009] According to the above configuration, the support unit and the boom are supported via the first drive unit, which simplifies the configuration in which the support unit supports the boom. The boom and the arm are supported via the second drive unit, which simplifies the configuration in which the boom supports the arm. The arm and the attachment are supported via the third drive unit, which simplifies the configuration in which the arm supports the attachment. Furthermore, the center line of the boom's width is located at a position that is included in the width of the arm, which allows the boom and the arm to be positioned in a straight line.

[0010] In the above construction machine, it is preferable that the tip of the boom is located offset toward one end in the width direction from the center line, the base end of the arm is located offset toward the other end in the width direction from the center line, and the second drive shaft is located between the tip of the boom and the base end of the arm.

[0011] In the above construction machine, it is preferable that the tip of the support part is located offset toward one end in the width direction from the center line, the base end of the boom is located offset toward the other end in the width direction from the center line, and the first drive shaft is located between the tip of the support part and the base end of the boom.

[0012] In the above construction machine, it is preferable that the tip of the arm is located offset toward one end in the width direction from the center line, the base end of the attachment is located offset toward the other end in the width direction from the center line, and the third drive shaft is located between the tip of the arm and the base end of the attachment.

[0013] In the above construction machine, it is preferable that the first drive unit comprises a first drive mechanism and a first reduction mechanism driven by the first drive mechanism, the first reduction mechanism having a first member on which one end of the first drive shaft is provided and a second member whose rotation is reduced relative to the first member of the first reduction mechanism and on which the other end of the first drive shaft is provided; the second drive unit comprises a second drive mechanism and a second reduction mechanism driven by the second drive mechanism, the second reduction mechanism having a third member on which one end of the second drive shaft is provided and a fourth member whose rotation is reduced relative to the third member of the second reduction mechanism and on which the other end of the second drive shaft is provided; the third drive unit comprises a third drive mechanism and a third reduction mechanism driven by the third drive mechanism, and the third reduction mechanism having a fifth member on which one end of the third drive shaft is provided and a sixth member whose rotation is reduced relative to the fifth member of the third reduction mechanism and on which the other end of the third drive shaft is provided.

[0014] In the above construction machine, it is preferable that the first drive mechanism is provided widthwise outside of the tip of the support part, the second drive mechanism is provided widthwise outside of the tip of the boom, and the third drive mechanism is provided widthwise outside of the tip of the arm.

[0015] In the above construction machine, it is preferable that the second drive unit comprises a second drive mechanism and a second reduction mechanism driven by the second drive mechanism, and that the center line of the boom width and the center line of the arm width are located between the distance between the application points of a pair of bearings provided near the outer periphery of the second reduction mechanism.

[0016] In the above construction machine, it is preferable that the first drive unit comprises a first drive mechanism and a first reduction mechanism driven by the first drive mechanism, and the center line of the width of the support unit and the center line of the width of the boom are located between the distance between the points of application of a pair of bearings provided near the outer periphery of the first reduction mechanism.

[0017] In the above construction machine, it is preferable that the third drive unit comprises a third drive mechanism and a third reduction mechanism driven by the third drive mechanism, and that the center line of the width of the arm and the center line of the width of the attachment are located between the distance between the points of application of a pair of bearings provided near the outer periphery of the third reduction mechanism.

[0018] A construction machine that solves the above problem comprises a boom and an arm whose base end is supported on the boom via a drive unit, the drive unit comprising a drive mechanism and a reduction mechanism driven by the drive mechanism, the reduction mechanism having a crankshaft to which the output of the drive mechanism is transmitted, a gear driven by the crankshaft, and an output unit with which the gear meshes, and at least a portion of the crankshaft wraps around both the boom and the arm in the longitudinal direction of the boom and the arm.

[0019] With the above configuration, the boom and arm are supported via the drive unit, which simplifies the configuration for supporting the arm by the boom. Furthermore, since at least a portion of the crankshaft wraps around both the boom and the arm in the longitudinal direction of the boom and the arm, the boom and the arm can be positioned in a straight line. [Effects of the Invention]

[0020] According to the present invention, it is possible to provide a construction machine and a work implement for the construction machine that have a simple configuration. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a left side view showing a configuration of an embodiment of a construction machine. FIG. [Figure 2] FIG. 2 is a left side view showing the configuration of the construction machine of the embodiment. [Figure 3] FIG. 2 is a plan view showing the configuration of an action section of the construction machine of the embodiment. [Figure 4] FIG. 2 is a cross-sectional view showing the configuration of a drive unit of the construction machine of the same embodiment. [Figure 5] FIG. 10 is a cross-sectional view showing the configuration of a drive unit of a construction machine according to a modified example. [Figure 6] FIG. 10 is a plan view showing the configuration of an action portion of a construction machine according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0022] (Present embodiment) An embodiment of a construction machine will be described below with reference to Figures 1 to 4. The construction machine is a backhoe.

[0023] (Construction Machinery 1) As shown in Figures 1 and 2, the construction machine 1 comprises a main body 2 and an acting unit 6. The main body 2 comprises a self-propelled running body 3 and a rotating unit 4 that is rotatably attached to the running body 3. The rotating unit 4 is provided with a support unit 5 that supports the acting unit 6. The rotating unit 4 may also be provided with a driver's cab where an operator sits. The acting unit 6 corresponds to the working equipment of the construction machine.

[0024] The working unit 6 includes a boom 7, an arm 8, and an attachment 9. A base end 7A of the boom 7 is supported by a tip end 5A of the support unit 5 of the main body 2 via a first drive unit 10. The boom 7 rotates relative to the support unit 5 when driven by the first drive unit 10. A base end 8A of the arm 8 is supported by a tip end 7B of the boom 7 via a second drive unit 20. The arm 8 rotates relative to the boom 7 when driven by the second drive unit 20. A base end 9A of the attachment 9 is supported by a tip end 8B of the arm 8 via a third drive unit 30. The attachment 9 rotates relative to the arm 8 when driven by the third drive unit 30.

[0025] As shown in FIG. 3 , one end 11A of the first drive shaft 11 of the first drive unit 10 is fixed to the tip end 5A of the support unit 5. The other end 11B of the first drive shaft 11 is fixed to the base end 7A of the boom 7. One end 21A of the second drive shaft 21 of the second drive unit 20 is fixed to the tip end 7B of the boom 7. The other end 21B of the second drive shaft 21 is fixed to the base end 8A of the arm 8. One end 31A of the third drive shaft 31 of the third drive unit 30 is fixed to the tip end 8B of the arm 8. The other end 31B of the third drive shaft 31 is fixed to the base end 9A of the attachment 9. The first drive shaft 11, second drive shaft 21, and third drive shaft 31 are imaginary members that transmit driving force. The center line P7 of the width W7 of the boom 7 is located at a position that is included in the width W8 of the arm 8. In other words, the boom 7 and the arm 8 are located on a substantially straight line. The width W7 is the maximum width of the boom 7. The width W8 is the maximum width of the arm 8.

[0026] The tip end 7B of the boom 7 is located offset to the left in FIG. 3, which is one end in the width direction, from the center line P7 of the boom 7. The base end 8A of the arm 8 is located offset to the right in FIG. 3, which is the other end in the width direction, from the center line P7 of the boom 7. A second drive shaft 21 is provided between the tip end 7B of the boom 7 and the base end 8A of the arm 8. The second drive unit 20 includes a second drive mechanism 22 and a second reduction mechanism 23 driven by the second drive mechanism 22. The second drive mechanism 22 is provided on the outside of the tip end 7B of the boom 7 in the width direction.

[0027] The tip end 5A of the support part 5 is located offset to the left in FIG. 3, which is one end in the width direction, from the center line P7 of the boom 7. The base end 7A of the boom 7 is located offset to the right in FIG. 3, which is the other end in the width direction, from the center line P7 of the boom 7. The first drive shaft 11 is provided between the tip end 5A of the support part 5 and the base end 7A of the boom 7. It is desirable that the base end 7A and the tip end 7B of the boom 7 be located offset to different left and right sides. The first drive part 10 includes a first drive mechanism 12 and a first reduction mechanism 13 driven by the first drive mechanism 12. The first drive mechanism 12 is provided on the outside of the tip end 5A of the support part 5 in the width direction.

[0028] The tip end 8B of the arm 8 is located offset to one end in the width direction from the center line P7 of the boom 7. The base end 9A of the attachment 9 is located offset to the other end in the width direction, i.e., the right side in FIG. 3, from the center line P7 of the boom 7. The third drive shaft 31 is located between the tip end 8B of the arm 8 and the base end 9A of the attachment 9. It is desirable that the base end 8A and the tip end 8B of the arm 8 are located offset to different left and right sides. The third drive unit 30 includes a third drive mechanism 32 and a third reduction mechanism 33 driven by the third drive mechanism 32. The third drive mechanism 32 is located outward in the width direction from the tip end 8B of the arm 8.

[0029] (Second driving unit 20) Next, we will explain the configuration of the second drive unit 20. Note that the configurations of the first drive unit 10 and the third drive unit 30 are similar to the configuration of the second drive unit 20, so explanations will be omitted.

[0030] As shown in Fig. 4, the second drive unit 20 is held at the tip 7B of the boom 7. The second drive mechanism 22 of the second drive unit 20 is an electric motor. Note that Fig. 3 is a schematic representation of the arrangement of the components of the second drive unit 20, and the size relationships between the electric motor and other components, for example, do not necessarily correspond to the actual ones.

[0031] The output shaft 22A of the second drive mechanism 22 penetrates the tip end 7B of the boom 7 and protrudes between the tip end 7B of the boom 7 and the base end 8A of the arm 8. The rotation axis P1 of the output shaft 22A allows the output shaft 22A to rotate in both forward and reverse directions. A plurality of teeth (not shown) are provided on the outer circumferential surface of the output shaft 22A. The second drive mechanism 22 is a power source that provides power to the second reduction mechanism 23.

[0032] (Second reduction mechanism 23) The second reduction mechanism 23 is a reducer that reduces the rotation of the output shaft 22A of the second drive mechanism 22 at a predetermined gear ratio and outputs the reduced rotation. The second reduction mechanism 23 includes a case 40. The case 40 includes a case main body 41, a plurality of teeth 42, and a flange 43. The rotation axis P1 of the output shaft 22A is positioned at the center of the case 40. Note that the case 40 is fixed to the tip portion 7B of the boom 7, through which the output shaft 22A passes, and therefore the case 40 corresponds to the first member, third member, and fifth member.

[0033] The case body 41 is fixed to the tip 7B of the boom 7. The case body 41 is cylindrical. A plurality of teeth 42 protrude from the inner peripheral surface of the case body 41. The plurality of teeth 42 are arranged at equal intervals in the circumferential direction. The teeth 42 are located near the center of the case body 41 in the axial direction. A flange 43 protrudes from the outer peripheral surface of the case body 41. The flange 43 is annular. The end face of the flange 43 faces the tip 7B of the boom 7. The flange 43 and the tip 7B of the boom 7 are fixed at multiple points by bolts B1.

[0034] (Career 50) The second reduction mechanism 23 includes a carrier 50. The carrier 50 includes a first plate portion 51, a second plate portion 52, and a plurality of pillar portions 53. The first plate portion 51 is located inside the case main body 41.

[0035] The first plate portion 51 is located closer to the arm 8 in the axial direction of the case body 41. The first plate portion 51 is disk-shaped. The diameter of the first plate portion 51 is smaller than the inner diameter of the case body 41. The central axis of the first plate portion 51 substantially coincides with the rotation axis P1. A bearing 44A is interposed between the outer peripheral surface of the first plate portion 51 and the inner peripheral surface of the case body 41. The bearing 44A is provided closer to the outer periphery of the second reduction mechanism 23. The first plate portion 51 has a plurality of first through holes 51H. The number of the first through holes 51H is, for example, three. The first through holes 51H are located at positions radially deviated from the rotation axis P1. The first through holes 51H penetrate the first plate portion 51 in the axial direction. The plurality of first through holes 51H are arranged at equal intervals in the circumferential direction.

[0036] The second plate portion 52 is located inside the case body 41. The second plate portion 52 is located axially closer to the boom 7 in the case body 41. The second plate portion 52 is disk-shaped. The diameter of the second plate portion 52 is the same as the diameter of the first plate portion 51. The central axis of the second plate portion 52 substantially coincides with the rotation axis P1. A bearing 44B is interposed between the outer circumferential surface of the second plate portion 52 and the inner circumferential surface of the case body 41. The bearing 44B is provided near the outer periphery of the second reduction mechanism 23. The second plate portion 52 has a plurality of second through holes 52H. The plurality of second through holes 52H are provided in pairs with the plurality of first through holes 51H provided in the first plate portion 51. That is, the number of second through holes 52H is the same as the number of first through holes 51H in the first plate portion 51. The second through holes 52H axially penetrate the second plate portion 52. The central axis of the second through-hole 52H substantially coincides with the central axis of the first through-hole 51H in the first plate portion 51 that is paired with the second through-hole 52H.

[0037] The plurality of pillar portions 53 protrude from the second plate portion 52 toward the arm 8 in the axial direction. The pillar portions 53 are located at positions radially offset from the rotation axis P1. The pillar portions 53 are cylindrical. The plurality of pillar portions 53 are arranged at equal intervals in the circumferential direction. The pillar portions 53 are integrally molded with the second plate portion 52. The end faces of the pillar portions 53 are in contact with the first plate portion 51. That is, the pillar portions 53 connect the first plate portion 51 and the second plate portion 52. The pillar portions 53 and the first plate portion 51 are fixed with bolts B2.

[0038] (First external gear 61) The second reduction gear mechanism 23 includes a first external gear 61. The first external gear 61 is located inside the case body 41. The first external gear 61 is located between the first plate portion 51 and the second plate portion 52 of the carrier 50 in the axial direction. Specifically, the first external gear 61 is located at the same position as the teeth 42 of the case 40 in the axial direction. The first external gear 61 is generally disk-shaped. The diameter of the first external gear 61 is smaller than the inner diameter of the case body 41. The central axis of the first external gear 61 is parallel to the rotation axis P1. A plurality of teeth are formed on the outer peripheral surface of the first external gear 61. The plurality of teeth are arranged at equal intervals in the circumferential direction. In FIG. 4, the teeth of the first external gear 61 are not shown. Among the plurality of teeth, teeth located in a partial range in the circumferential direction mesh with the teeth 42 of the case 40. On the other hand, among the plurality of teeth, there is a gap between the teeth positioned outside the above range in the circumferential direction and the teeth 42 of the case 40.

[0039] The first external gear 61 has a plurality of first through holes 61A. The first through holes 61A are located at positions radially offset from the central axis of the first external gear 61. The first through holes 61A penetrate the first external gear 61 in the axial direction. The first through holes 61A are provided corresponding to the respective pillar portions 53. The pillar portions 53 penetrate through the first through holes 61A. The diameter of the first through holes 61A is larger than the diameter of the pillar portions 53.

[0040] The first external gear 61 has a plurality of second through holes 61B. The second through holes 61B are provided in pairs with the first through holes 51H provided in the first plate portion 51. In other words, the number of second through holes 61B is the same as the number of first through holes 51H provided in the first plate portion 51. The second through holes 61B are located at positions radially offset from the central axis of the first external gear 61. The second through holes 61B pass through the first external gear 61 in the axial direction. The second through holes 61B are in communication with their corresponding first through holes 51H in the first plate portion 51.

[0041] (Second external gear 62) The second reduction mechanism 23 includes a second external gear 62. The second external gear 62 is located inside the case main body 41. The second external gear 62 is adjacent to the first external gear 61 in the axial direction. That is, like the first external gear 61, the second external gear 62 is located between the first plate portion 51 and the second plate portion 52 of the carrier 50 in the axial direction. The second external gear 62 is also located at the same position in the axial direction as the teeth 42 of the case 40. The configuration of the second external gear 62 is the same as the configuration of the first external gear 61. That is, the second external gear 62 includes a first through hole 62A for each column portion 53. The second external gear 62 also includes a plurality of second through holes 62B that are paired with the plurality of second through holes 52H provided in the second plate portion 52. The second through holes 62B are in communication with the paired second through holes 52H in the second plate portion 52. At the same time, the second through hole 62B also communicates with the second through hole 61B of the first external gear 61. As a result, the first through hole 51H of the first plate portion 51, the second through hole 61B of the first external gear 61, the second through hole 62B of the second external gear 62, and the second through hole 52H of the second plate portion 52 form a continuous shaft hole. There are multiple shaft holes, the number of which corresponds to the number of first through holes 51H of the first plate portion 51. At the same time, the shaft holes are lined up at equal intervals in the circumferential direction.

[0042] (Crankshaft 70) The second reduction mechanism 23 includes a plurality of crankshafts 70. A crankshaft 70 is provided for each shaft hole. The crankshaft 70 includes a main shaft 71, a first eccentric portion 72, and a second eccentric portion 73.

[0043] The main shaft 71 is cylindrical. The main shaft 71 extends in the axial direction. A large portion of the main shaft 71 is located in the shaft hole. More specifically, the end of the main shaft 71 that is closer to the arm 8 in the axial direction is located in the first through-hole 51H of the first plate portion 51. A large portion of the main shaft 71 that is closer to the boom 7 in the axial direction is located in the second through-hole 52H of the second plate portion 52. A portion of the main shaft 71 protrudes from the second through-hole 52H of the second plate portion 52 toward the boom 7.

[0044] The first eccentric portion 72 is located midway in the axial direction of the main shaft 71. More specifically, the first eccentric portion 72 is located inside the second through hole 61B of the first external gear 61. The first eccentric portion 72 protrudes from the outer circumferential surface of the main shaft 71. The outer shape of the first eccentric portion 72 is circular when viewed in a plan view facing the axial direction. The center of the first eccentric portion 72 is offset from the center of the main shaft 71 when viewed in a plan view facing the axial direction. A bearing 63A is interposed between the outer circumferential surface of the first eccentric portion 72 and the second through hole 61B of the first external gear 61. The bearings 44A and 44B are provided closer to the outer periphery than the bearing 63A.

[0045] The second eccentric portion 73 is located in a portion of the main shaft 71 in the axial direction. More specifically, the second eccentric portion 73 is located inside the second through hole 62B of the second external gear 62. Like the first eccentric portion 72, the second eccentric portion 73 protrudes from the outer peripheral surface of the main shaft 71. The outer shape of the second eccentric portion 73 is circular when viewed in a plan view facing the axial direction. The center of the second eccentric portion 73 is shifted from the center of the first eccentric portion 72 and the center of the main shaft 71 when viewed in a plan view facing the axial direction. A bearing 63B is interposed between the outer peripheral surface of the second eccentric portion 73 and the second through hole 62B of the second external gear 62. The bearings 44A and 44B are provided closer to the outer periphery than the bearing 63B.

[0046] The second reduction gear mechanism 23 includes a plurality of transmission gears 74. One transmission gear 74 is provided for each crankshaft 70. The transmission gear 74 is attached to a portion of the main shaft 71 that protrudes axially from the second through-hole 52H of the second plate portion 52 toward the boom 7. The transmission gear 74 is generally annular. The main shaft 71 is fixed to a central hole of the transmission gear 74. A plurality of teeth (not shown) are formed on the outer circumferential surface of the transmission gear 74.

[0047] The transmission gear 74 meshes with the teeth of the output shaft 22A of the second drive mechanism 22. The transmission gear 74 transmits the rotation of the output shaft 22A of the second drive mechanism 22 to the crankshaft 70. The crankshaft 70 transmits its own rotation, which is caused by the rotation of the transmission gear 74, to the first external gear 61 and the second external gear 62 via the first eccentric portion 72 and the second eccentric portion 73. The first external gear 61 and the second external gear 62 oscillate and rotate upon receiving forces from the first eccentric portion 72 and the second eccentric portion 73. That is, the first external gear 61 rotates relative to the case main body 41 while oscillating so that the circumferential range in which it meshes with the teeth 42 of the case 40 is interchanged. The same is true for the second external gear 62. The rotation of the first external gear 61 and the second external gear 62 is transmitted to the carrier 50 via the column portion 53. The carrier 50 then rotates about the rotation axis P1. That is, the carrier 50 rotates relative to the case 40. Therefore, the arm 8 rotates relative to the boom 7. The carrier 50, whose rotation is decelerated relative to the case 40, corresponds to the second member, fourth member, and sixth member. The carrier 50 also corresponds to an output section with which a first external gear 61 and a second external gear 62 driven by a crankshaft 70 mesh.

[0048] At least a portion of the crankshaft 70 wraps around both the boom 7 and the arm 8 in a longitudinal cross section of the boom 7 and the arm 8. That is, the boom 7, the crankshaft 70, and the arm 8 are arranged side by side in the longitudinal direction.

[0049] (Action of this embodiment) Next, the operation of the construction machine 1 configured as above will be described with reference to FIGS.

[0050] 1 and 2, the boom 7 rotates about a first drive shaft 11 relative to the support part 5 as a result of being driven by a first drive part 10. That is, a first reduction mechanism 13 reduces the speed of rotation of an output shaft 22A of a first drive mechanism 12 fixed to a tip end 5A of the support part 5, thereby rotating a base end 7A of the boom 7. The boom 7 rotates relative to the support part 5 in accordance with the amount of rotation of the output shaft 22A of the first drive mechanism 12.

[0051] Driven by second drive unit 20, arm 8 rotates about second drive shaft 21 relative to boom 7. That is, second reduction mechanism 23 reduces the speed of rotation of the output shaft of second drive mechanism 22 fixed to tip end 8B of boom 7, causing base end 8A of arm 8 to rotate. Arm 8 rotates relative to boom 7 in accordance with the amount of rotation of the output shaft of second drive mechanism 22.

[0052] The attachment 9 rotates around a third drive shaft 31 relative to the arm 8 as a result of drive by a third drive unit 30. That is, a third reduction mechanism 33 reduces the speed of rotation of the output shaft of a third drive mechanism 32 fixed to a tip end 8B of the arm 8, causing the base end 9A of the attachment 9 to rotate. The attachment 9 rotates relative to the arm 8 in accordance with the amount of rotation of the output shaft of the third drive mechanism 32.

[0053] As shown in Figure 3, the tip end 5A of the support part 5 is located to the left of the first reduction gear mechanism 13 in Figure 3. The base end 7A of the boom 7 is located to the right of the first reduction gear mechanism 13 in Figure 3. Therefore, the support part 5, the first reduction gear mechanism 13 (crank shaft), and the boom 7 are arranged side by side in the longitudinal direction, and can be made smaller in the width direction.

[0054] The tip end 7B of the boom 7 is located to the left of the second reduction mechanism 23 in Figure 3. The base end 8A of the arm 8 is located to the right of the second reduction mechanism 23 in Figure 3. Therefore, the boom 7, the second reduction mechanism 23 (crank shaft 70), and the arm 8 are arranged side by side in the longitudinal direction, and can be made smaller in size in the width direction.

[0055] The tip end 8B of the arm 8 is located to the left of the third reduction mechanism 33 in FIG. 3. The base end 9A of the attachment 9 is located to the right of the third reduction mechanism 33 in FIG. 3. Therefore, the arm 8, the third reduction mechanism 33 (crank shaft), and the base end 9A of the attachment 9 are arranged side by side in the longitudinal direction, and the size can be reduced in the width direction.

[0056] (Effects of this embodiment) Next, the effects of this embodiment will be described. (1) Because the support unit 5 and the boom 7 are supported via the first drive unit 10, the configuration in which the support unit 5 supports the boom 7 can be simplified. Because the boom 7 and the arm 8 are supported via the second drive unit 20, the configuration in which the boom 7 supports the arm 8 can be simplified. Because the arm 8 and the attachment 9 are supported via the third drive unit 30, the configuration in which the arm 8 supports the attachment 9 can be simplified. Furthermore, because the center line P7 of the width W7 of the boom 7 is located at a position that is included in the width W8 of the arm 8, the boom 7 and the arm 8 can be positioned on a straight line. Therefore, the boom 7 and the arm 8 can be made smaller in the width direction.

[0057] (2) The first drive shaft 11 is provided between the tip end 7B of the boom 7, which is located to the left in FIG. 3, which is one end in the width direction of the boom 7 relative to the center line P7 of the boom 7, and the base end 8A of the arm 8, which is located to the right in FIG. 3, which is the other end in the width direction of the boom 7 relative to the center line P7 of the boom 7, without shifting the boom 7 and the arm 8 in the width direction. Therefore, the length in the width direction including the boom 7 and the arm 8 can be reduced.

[0058] (3) The second drive shaft 21 is provided between the tip end 5A of the support part 5, which is located to the left in FIG. 3, which is one end in the width direction of the boom 7, and the base end 7A of the boom 7, which is located to the right in FIG. 3, which is the other end in the width direction of the boom 7, without shifting the support part 5 and the boom 7 in the width direction. Therefore, the length in the width direction including the support part 5 and the boom 7 can be reduced.

[0059] (4) The third drive shaft 31 is provided between the tip end 8B of the arm 8, which is located to the left in FIG. 3, which is one end in the width direction of the boom 7, and the base end 9A of the attachment 9, which is located to the right in FIG. 3, which is the other end in the width direction of the boom 7, without shifting the arm 8 and the attachment 9 in the width direction. Therefore, the length in the width direction including the arm 8 and the base end 9A of the attachment 9 can be reduced.

[0060] (5) The first drive unit 10 can reduce the speed of rotation of the first drive mechanism 12 by the first reduction mechanism 13. The second drive unit 20 can reduce the speed of rotation of the second drive mechanism 22 by the second reduction mechanism 23. The third drive unit 30 can reduce the speed of rotation of the third drive mechanism 32 by the third reduction mechanism 33.

[0061] (6) Because the first drive mechanism 12 is provided widthwise outward of the tip 5A of the support part 5, the width of the tip 5A of the support part 5 and the width of the base end 7A of the boom 7 can be determined regardless of the size of the first drive mechanism 12. Because the second drive mechanism 22 is provided widthwise outward of the tip 7B of the boom 7, the width of the tip 7B of the boom 7 and the width of the base end 8A of the arm 8 can be determined regardless of the size of the second drive mechanism 22. Because the third drive mechanism 32 is provided widthwise outward of the tip 8B of the arm 8, the width of the tip 8B of the arm 8 and the width of the base end 9A of the attachment 9 can be determined regardless of the size of the third drive mechanism 32.

[0062] (Other embodiments) The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0063] In the above embodiment, the positions of the distance between the load points of the bearings and the center lines of the members may be specified. Specifically, as shown in FIG. 5, a distance L2 between the load points of a pair of bearings 44A, 44B provided near the outer periphery of the second reduction mechanism 23 is set. The distance between the load points is determined depending on the bearings installed. Similarly, as shown in FIG. 6, a distance L1 between the load points of a pair of bearings (indicated by ●) provided near the outer periphery of the first reduction mechanism 13 is set. A distance L3 between the load points of a pair of bearings (indicated by ●) provided near the outer periphery of the third reduction mechanism 33 is set. The center line P7 of the width W7 of the boom 7 and the center line P8 of the width W8 of the arm 8 are located between the distance L2 between the load points of the pair of bearings 44A, 44B provided near the outer periphery of the second reduction mechanism 23. This configuration allows the width W7 of the boom 7 and the width W8 of the arm 8 to be reduced while ensuring a safety factor against external loads on the second drive unit 20. Furthermore, the center line P5 of the width W5 of the support unit 5 and the center line P7 of the width W7 of the boom 7 are located between the distance L1 between the points of application of a pair of bearings provided near the outer periphery of the first reduction gear mechanism 13. With this configuration, the width W5 of the support unit 5 and the width W7 of the boom 7 can be reduced while ensuring a safety factor against external loads of the first drive unit 10. Furthermore, the center line P8 of the width W8 of the arm 8 and the center line P9 of the width W9 of the attachment 9 are located between the distance L3 between the points of application of a pair of bearings provided near the outer periphery of the third reduction gear mechanism 33. With this configuration, the width W8 of the arm 8 and the width W9 of the attachment 9 can be reduced while ensuring a safety factor against external loads of the third drive unit 30. Note that in at least one of the first reduction gear mechanism 13, the second reduction gear mechanism 23, and the third reduction gear mechanism 33, the center line of the member may be located between the distance between the points of application of the bearings.

[0064] In the above embodiment, the first drive mechanism 12 is provided on the widthwise outer side of the tip end 5A of the support part 5. However, the first drive mechanism 12 may be provided between the tip end 5A of the support part 5 and the base end 7A of the boom 7.

[0065] In the above embodiment, the second drive mechanism 22 is provided on the widthwise outer side of the tip end 7B of the boom 7. However, the second drive mechanism 22 may be provided between the tip end 7B of the boom 7 and the base end 8A of the arm 8.

[0066] In the above embodiment, the third drive mechanism 32 is provided on the widthwise outer side of the tip end 8B of the arm 8. However, the third drive mechanism 32 may be provided between the tip end 8B of the arm 8 and the base end 9A of the attachment 9.

[0067] In the above embodiment, the configurations of the first reduction mechanism 13, the second reduction mechanism 23, and the third reduction mechanism 33 are not limited to those in the above embodiment. The reduction mechanisms may be any mechanism capable of reducing the rotation speed of the drive mechanism.

[0068] In the above embodiment, the first drive unit 10 includes the first drive mechanism 12 and the first reduction mechanism 13. However, if the drive force can be transmitted by the first drive mechanism 12 alone, the first reduction mechanism 13 may be omitted.

[0069] In the above embodiment, the second drive unit 20 includes the second drive mechanism 22 and the second reduction mechanism 23. However, if the drive force can be transmitted by the second drive mechanism 22 alone, the second reduction mechanism 23 may be omitted.

[0070] In the above embodiment, the third drive unit 30 includes the third drive mechanism 32 and the third reduction mechanism 33. However, if the drive force can be transmitted by the third drive mechanism 32 alone, the third reduction mechanism 33 may be omitted.

[0071] In the above embodiment, the tip 8B of the arm 8 is located offset to one end in the width direction from the center line P7 of the boom 7, and the base end 9A of the attachment 9 is located offset to the other end in the width direction from the center line P7 of the boom 7. However, the tip 8B of the arm 8 does not have to be located offset to one end in the width direction from the center line P7 of the boom 7, and the base end 9A of the attachment 9 does not have to be located offset to the other end in the width direction from the center line P7 of the boom 7.

[0072] In the above embodiment, the tip end 5A of the support part 5 is located offset to one end in the width direction from the center line P7 of the boom 7, and the base end 8A of the boom 7 is located offset to the other end in the width direction from the center line P7 of the boom 7. However, the tip end 5A of the support part 5 does not have to be located offset to one end in the width direction from the center line P7 of the boom 7, and the base end 8A of the boom 7 does not have to be located offset to the other end in the width direction from the center line P7 of the boom 7.

[0073] In the above embodiments, if an object is made up of multiple objects, the multiple objects may be integrated, and conversely, if an object is made up of a single object, it may be divided into multiple objects. Regardless of whether the objects are integrated or not, it is sufficient that the object of the invention can be achieved. [Explanation of symbols]

[0074] P1: Rotation axis P5: Center line of support P7: Center line of the boom P8: Center line of arm P9...Center line of attachment W5: Width of support W7…Boom width W8…Arm width W9…Attachment width 1. Construction machinery 2...Main body 3...Running body 4...Rotating body 5...Support part 5A…Tip 6…Action part (work equipment) 7...Boom 7A…Proximal end 7B…Tip 8...Arm 8A…Proximal end 8B…Tip 9...Attachment 9A…Proximal end 10...First drive unit 11...First drive shaft 11A…One end 11B...other end 12...First drive mechanism 13...1st reduction mechanism 20...Second drive unit 21...Second drive shaft 21A…One end 21B...other end 22...Second drive mechanism 22A...Output shaft 23...Second reduction mechanism 30...Third drive unit 31...Third drive shaft 31A…One end 31B...other end 32...Third drive mechanism 33…Third reduction mechanism 40…case 41...Case body 42...tooth 43...Flange 44A, 44B...Bearings 50...Career 51...1st plate part 51H…1st through hole 52…Second plate part 52H…Second through hole 53...Column part 61...First external gear 61A…1st through hole 61B…Second through hole 62...Second external gear 62A...First through hole 62B…Second through hole 63A, 63B...Bearings 70...Crankshaft 71...Spindle 72...First eccentric part 73…Second eccentric part 74...Transmission gear

Claims

1. a boom having a base end supported by a support portion of the main body portion via a first drive portion; an arm having a base end supported on the boom via a second drive unit; an attachment having a base end supported on the arm via a third drive unit, one end of a first drive shaft of the first drive unit is fixed to a tip end of the support unit, The other end of the first drive shaft is fixed to a base end of the boom, one end of a second drive shaft of the second drive unit is fixed to a tip portion of the boom, The other end of the second drive shaft is fixed to the base end of the arm, one end of a third drive shaft of the third drive unit is fixed to a tip end of the arm, The other end of the third drive shaft is fixed to a base end of the attachment, The center line of the width of the boom is located at a position included in the width of the arm. Construction machinery.

2. The tip of the boom is provided offset toward one end in the width direction from the center line, the base end of the arm is located offset from the center line toward the other end in the width direction, The second drive shaft is provided between the tip end of the boom and the base end of the arm. The construction machine according to claim 1.

3. a tip end of the support portion is provided so as to be offset toward one end in the width direction from the center line, the base end of the boom is provided offset toward the other end in the width direction from the center line, The first drive shaft is provided between the tip end of the support part and the base end of the boom. The construction machine according to claim 1.

4. the tip end of the arm is provided offset toward one end in the width direction from the center line, The base end of the attachment is located closer to the other end in the width direction than the center line, The third drive shaft is provided between the tip end of the arm and the base end of the attachment. The construction machine according to claim 1.

5. the first drive unit includes a first drive mechanism and a first reduction mechanism driven by the first drive mechanism; the first reduction mechanism includes a first member to which one end of the first drive shaft is provided, and a second member whose rotation is reduced relative to the first member of the first reduction mechanism and to which the other end of the first drive shaft is provided, the second drive unit includes a second drive mechanism and a second reduction mechanism driven by the second drive mechanism, the second reduction mechanism includes a third member to which one end of the second drive shaft is provided, and a fourth member whose rotation is reduced relative to the third member of the second reduction mechanism and to which the other end of the second drive shaft is provided, the third drive unit includes a third drive mechanism and a third reduction mechanism driven by the third drive mechanism, The third reduction mechanism includes a fifth member to which one end of the third drive shaft is provided, and a sixth member whose rotation is reduced relative to the fifth member of the third reduction mechanism and to which the other end of the third drive shaft is provided. The construction machine according to any one of claims 1 to 4.

6. the first drive mechanism is provided on the outer side of the tip end of the support portion in the width direction, the second drive mechanism is provided on the outer side of the tip of the boom in the width direction, The third drive mechanism is provided on the outer side of the tip end of the arm in the width direction. The construction machine according to claim 5.

7. the second drive unit includes a second drive mechanism and a second reduction mechanism driven by the second drive mechanism, The center line of the width of the boom and the center line of the width of the arm are positioned between the distance between the application points of a pair of bearings provided near the outer periphery of the second reduction mechanism. The construction machine according to any one of claims 1 to 4.

8. the first drive unit includes a first drive mechanism and a first reduction mechanism driven by the first drive mechanism; The center line of the width of the support portion and the center line of the width of the boom are positioned between the distance between the application points of a pair of bearings provided near the outer periphery of the first reduction mechanism. The construction machine according to any one of claims 1 to 4.

9. the third drive unit includes a third drive mechanism and a third reduction mechanism driven by the third drive mechanism, The center line of the width of the arm and the center line of the width of the attachment are positioned between the centers of application of a pair of bearings provided near the outer periphery of the third reduction mechanism. The construction machine according to any one of claims 1 to 4.

10. Boom and an arm having a base end supported on the boom via a drive unit, the drive unit includes a drive mechanism and a speed reduction mechanism driven by the drive mechanism, the reduction mechanism includes a crankshaft to which an output of the drive mechanism is transmitted, a gear driven by the crankshaft, and an output portion with which the gear meshes, At least a portion of the crankshaft overlaps both the boom and the arm in the longitudinal direction of the boom and the arm. Construction machinery.

11. a boom having a base end supported via a first drive unit on a support portion of a main body of the construction machine; an arm having a base end supported on the boom via a second drive unit; an attachment having a base end supported on the arm via a third drive unit, one end of a first drive shaft of the first drive unit is fixed to a tip end of the support unit, The other end of the first drive shaft is fixed to a base end of the boom, one end of a second drive shaft of the second drive unit is fixed to a tip portion of the boom, The other end of the second drive shaft is fixed to the base end of the arm, one end of a third drive shaft of the third drive unit is fixed to a tip end of the arm, The other end of the third drive shaft is fixed to a base end of the attachment, The center line of the width of the boom is located at a position included in the width of the arm. Construction machinery work equipment.

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