Construction machinery

Abstract

To provide construction machinery whose structure can be reliably simplified through electrification. [Solution] The excavator of this embodiment comprises a self-propelled rotating body 103, an action part 104 attached to the rotating body 103, and reduction mechanism parts 1 to 3 provided on a part of the action part 104 and rotatingly driving this part. The reduction mechanism parts 1 to 3 each comprise a reduction unit 10 and an electric motor 22 that drives the reduction unit.

Description

Technical Field

[0001] The present invention relates to construction machinery.

Background Art

[0002] For example, construction machinery such as a hydraulic excavator includes a traveling body that travels on its own, and a revolving body that is rotatably provided on the traveling body. The revolving body includes an operation cab on which an operator rides. Further, an operating portion is provided on the revolving body, one end of which is rotatably (oscillatably) connected. Examples of the operating portion include a boom, an arm having one end rotatably connected to the other end of the boom on the side opposite to the revolving body, and a bucket having one end rotatably connected to the other end of the arm on the side opposite to the boom.

[0003] In many cases, hydraulic actuators of linear motion mechanisms are provided at the connection portions between the revolving body and the boom, between the boom and the arm, and between the arm and the bucket. The hydraulic actuator includes a cylinder tube and a piston rod that moves in and out with respect to the cylinder tube. For example, at the connection portion between the revolving body and the boom, the cylinder tube is rotatably attached to either the revolving body or the boom, and the tip of the piston rod is rotatably attached to the other. The connection portions between the boom and the arm and between the arm and the bucket are similarly provided with hydraulic actuators. Under such a configuration, by moving the piston rod in and out with respect to the cylinder tube, the boom, the arm, and the bucket are swung.

[0004] By the way, in recent years, electrification has been desired from the viewpoint of simplifying the structure of construction machinery. For this reason, a technique using an electric cylinder of a linear motion mechanism incorporating a ball screw type reduction gear instead of a hydraulic actuator has been disclosed. The attachment configuration of this ball screw type reduction gear to construction machinery is the same as that of a hydraulic cylinder. That is, for example, the cylinder is rotatably attached to either the revolving body or the boom, and the tip of the piston is rotatably attached to the other.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2003-82707 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, in the conventional technology described above, it is necessary to rotatably support the cylinders and pistons on the boom, etc., so a rotary mechanism is used in addition to the linear motion mechanism. That is, in order to rotatably support the cylinders and pistons on the boom, etc., a shaft and bearings for rotatably supporting the shaft are prepared as a rotary mechanism, and the cylinders and pistons are rotatably connected to the boom, etc. via this rotary mechanism. In this way, because a linear motion mechanism and a rotary mechanism are used in combination, there was a problem in that it was difficult to simplify the structure of the construction machinery.

[0007] This invention provides construction machinery whose structure can be reliably simplified in conjunction with electrification. [Means for solving the problem]

[0008] A construction machine according to one aspect of the present invention comprises a self-propelled main body, an operating part attached to the main body, and a reduction mechanism provided on a part of the operating part for rotationally driving the part, wherein the reduction mechanism comprises a reduction unit and a drive unit for driving the reduction unit.

[0009] With this configuration, the working part can be oscillated using only the reduction mechanism that rotates a portion of the working part, that is, using only the rotation mechanism. Therefore, as construction mechanisms are electrified, the structure of the construction mechanism can be significantly simplified.

[0010] In the above configuration, the reduction unit may be an eccentric oscillating type reduction unit comprising a first member and a second member that rotate relative to each other around the same first rotation axis, and at least one crankshaft disposed between the first member and the second member, which receives power from the drive unit and rotates about a second rotation axis along the first rotation axis, and which reduces the rotation of the crankshaft and transmits it to the second member, thereby reducing the rotation of the second member relative to the first member.

[0011] In the above configuration, the device has a plurality of crankshafts, and an external tooth member having external teeth that oscillates around the first rotation axis by the crankshafts, the first member being a case having internal teeth that mesh with the external teeth, and the second member being a carrier that rotatably supports the crankshafts and is rotatably supported by the first member via bearings, and rotates at a reduced speed relative to the case by the crankshafts.

[0012] In the above configuration, the drive unit may be fixed to the first member.

[0013] In the above configuration, the working part includes a boom rotatably supported on the main body, an arm rotatably supported on the opposite side of the boom from the main body, and an attachment rotatably supported on the opposite side of the arm from the boom, wherein the boom is provided on the main body via a first reduction mechanism, the arm is provided on the boom via a second reduction mechanism having a smaller transmission torque capacity than the first reduction mechanism, and the attachment is provided on the arm via a third reduction mechanism having a smaller transmission torque than the second reduction mechanism.

[0014] In the above configuration, the working part includes a boom rotatably supported on the main body, an arm rotatably supported on the opposite side of the boom from the main body, and an attachment rotatably supported on the opposite side of the arm from the boom. The boom may be provided on the main body via a first reduction mechanism, the arm may be provided on the boom via a second reduction mechanism that is lighter than the weight of the first reduction mechanism, and the attachment may be provided on the arm via a third reduction mechanism that is lighter than the weight of the second reduction mechanism.

[0015] In the above configuration, each of the reduction gear mechanisms may be arranged such that the rotation axes of the reduction gears are aligned in the same direction.

[0016] In the above configuration, the main body has a support that rotatably supports the working part, and the working part may include a boom whose side is rotatably supported by the support, an arm which is rotatably supported on the side of the boom opposite to the main body, and on the side, and an attachment which is rotatably supported on the side of the arm opposite to the boom.

[0017] In the above configuration, the working part may include a boom that is long in one direction and rotatably supported on the main body, an arm that is rotatably supported on the side of the boom opposite to the main body and on the side of the boom in the short direction, and an attachment that is rotatably supported on the side of the arm opposite to the boom and on the same side as the side on which the boom is positioned.

[0018] In the above configuration, the main body includes a self-propelled vehicle, a rotating vehicle that rotates relative to the vehicle, and an operating chamber provided on the rotating vehicle and arranged horizontally alongside the operating unit, and the drive unit may be located on the side of the operating unit facing the operating chamber.

[0019] With the above configuration, the main body portion includes a self-propelled traveling body, a swiveling body that swivels with respect to the traveling body, and an operation cab provided on the swiveling body and arranged side by side with the working portion in the horizontal direction. The drive portion may be arranged on the side surface of the working portion opposite to the operation cab.

[0020] A construction machine according to another aspect of the present invention includes a self-propelled main body portion, a speed reduction mechanism portion having a speed reduction portion and a drive portion that drives the speed reduction portion, a boom rotatably supported on the main body portion via the first speed reduction mechanism portion, an arm rotatably supported on the boom via a second speed reduction mechanism portion having a smaller transmission torque capacity than the first speed reduction mechanism portion, and an attachment rotatably supported on the arm via a third speed reduction mechanism portion having a smaller transmission torque than the second speed reduction mechanism portion.

[0021] By configuring in this way, the swinging operation of the boom with respect to the main body portion, the swinging operation of the arm with respect to the boom, and the swinging operation of the attachment with respect to the arm can be performed only by each speed reduction mechanism portion, that is, only by the rotation mechanism. Therefore, as the construction machine is electrified, the structure of the construction machine can be surely simplified.

[0022] With the above configuration, each speed reduction mechanism portion may be arranged such that the rotation axes of the speed reduction portions are along the same direction.

Advantages of the Invention

[0023] The above-described construction machine can surely simplify the structure with electrification.

Brief Description of the Drawings

[0024] [Figure 1] Schematic configuration diagram of the excavator in the embodiment of the present invention as viewed from the side. [Figure 2] Schematic configuration diagram of the excavator in the embodiment of the present invention as viewed from above. [Figure 3] Cross-sectional view of the first speed reduction mechanism portion in the embodiment of the present invention. [Figure 4] Cross-sectional view taken along line A-A of FIG. 3. [Figure 5] A schematic diagram of a shovel viewed from above in a first modified embodiment of the present invention. [Figure 6] A schematic diagram showing the working part of a second modified embodiment of the present invention, viewed from above. [Modes for carrying out the invention]

[0025] Next, embodiments of the present invention will be described with reference to the drawings.

[0026] <Shovel> Figure 1 is a schematic diagram of a shovel 100, an embodiment of the construction machinery of the present invention, viewed from the side. In the following description, the front facing an operator (not shown) operating the shovel 100 will be simply referred to as the front, and the direction horizontally opposite to the front will be referred to as the rear. The vertical direction when the shovel 100 is positioned on the road surface will be simply referred to as the vertical direction. The direction perpendicular to the front-rear direction and the vertical direction will be referred to as the vehicle width direction. Figure 1 shows the shovel 100 as viewed from the vehicle width direction.

[0027] As shown in Figure 1, the shovel (an example of a construction machine according to the claims) 100 comprises a self-propelled traveling body (an example of a main body, traveling body according to the claims) 101, a slewing body (an example of a main body, slewing body according to the claims) 103 provided on the upper part of the traveling body 101 via a slewing mechanism 102 and slewing relative to the traveling body 101, and an operating part 104 provided on the slewing body 103. The traveling body 101 and the slewing mechanism 102 are driven by, for example, an electric motor with a reduction gear (not shown). The traveling body 101 comprises, for example, two caterpillar tracks 105 arranged in the width direction of the vehicle. However, it is not limited to this, and wheels or the like may be used instead of caterpillar tracks 105.

[0028] Figure 2 is a schematic diagram of the shovel 100 as seen from above. An operating room 106 is provided on the front side of the slewing body 103, and at an off-center position on one side. The operator operates the shovel 100 from this operating room 106. A plate-shaped support part 107 is provided on the front side of the slewing body 103, approximately in the center in the vehicle width direction, adjacent to the operating room 106. The working part 104 is attached to this support part 107.

[0029] The working unit 104 comprises a boom 108 and an arm 109 that are long in the front-rear direction, and a bucket (an example of the attachment according to the claim) 110. These boom 108, arm 109, and bucket 110 are rotatably connected via three reduction mechanism sections 1, 2, 3 (first reduction mechanism section 1, second reduction mechanism section 2, and third reduction mechanism section 3).

[0030] Specifically, one longitudinal end 108a of the boom 108 is rotatably connected to the support section 107 via the first reduction mechanism section 1. One longitudinal end 109a of the arm 109 is rotatably connected to the other longitudinal end 108b of the boom 108 via the second reduction mechanism section 2. The bucket 110 is rotatably connected to the other longitudinal end 109b of the arm 109 via the third reduction mechanism section 3. The boom 108 is attached to the side 107a of the support section 107 on the side opposite to the control room 106 in the thickness direction. The arm 109 is attached to the first side 108c of the boom 108 on the side opposite to the control room 106 in the short direction. The bucket 110 is attached to the first side 109c of the arm 109 on the control room 106 side in the short direction.

[0031] <1st reduction mechanism section> Figure 3 is a cross-sectional view of the first reduction gear mechanism. The basic configuration of each reduction mechanism section 1 to 3 is the same. Therefore, in the following, only the first reduction mechanism section 1 will be described, and the descriptions of the second reduction mechanism section 2 and the third reduction mechanism section 3 will be omitted and explained as needed. As shown in Figure 3, the first reduction mechanism 1 comprises an electric motor (an example of the drive unit according to the claim) 22 and a reduction unit 10 that reduces the rotation of the motor shaft 22a of the electric motor 22 and outputs the result.

[0032] <Electric motor> Figure 4 is a cross-sectional view along line AA in Figure 3. As shown in Figures 3 and 4, the electric motor 22 is fastened and fixed to the first side surface 108c of the boom 108 by bolts 120. A through hole 111 is formed in the boom 108 at a position corresponding to the electric motor 22, penetrating in the short direction of the boom 108. The motor shaft 22a of the electric motor 22 is inserted into this through hole 111. The motor shaft 22a protrudes toward the support portion 107. The axis of the motor shaft 22a coincides with the rotation axis of the boom 108 relative to the support portion 107 (an example of the first rotation axis of the claim) C1. In the following description, the direction of the rotation axis C1 will be simply referred to as the axial direction, the radial direction of the motor shaft 22a will be simply referred to as the radial direction, and the rotation direction of the motor shaft 22a will be referred to as the circumferential direction.

[0033] <Deceleration part> The reduction gear 10 is fixed to the second side 108d of the boom 108, which is opposite to the first side 108c (towards the control room 106). The reduction gear 10 is positioned alongside the electric motor 22 in the direction of the rotation axis C1. The rotation axis of the reduction gear 10 also coincides with the axial direction. The reduction unit 10 comprises a cylindrical case 11, a carrier 14 positioned radially inside the case 11, an input shaft 16 that provides a driving force to rotate the carrier 14, and a reduction output unit 18 (see Figure 5) that rotates the carrier 14 at a rotational speed reduced by a predetermined ratio to the rotational speed of the input shaft 16.

[0034] <Case> An outer flange portion 11a is integrally molded on the outer circumferential surface of the case 11, protruding radially outward. The outer flange portion 11a has a square cross-section along the axial direction. The second side surface 108d of the boom 108 is superimposed on the end face 11b of the outer flange portion 11a on the boom 108 side in the axial direction. The case 11 is fastened and fixed to the boom 108 by bolts 121. Internal teeth 24 are provided on the inner circumferential surface of the case 11. The internal teeth 24 are pin-shaped (cylindrical) teeth provided on the inner circumferential surface of the case 11. Multiple internal teeth 24 are arranged at equal intervals in the circumferential direction.

[0035] <Career> The carrier 14 is rotatably supported in the case 11 by a pair of main bearings (an example of the bearings of the claim) 26, which are spaced apart in the axial direction. The main bearings 26 are, for example, angular contact ball bearings. The carrier 14 is positioned coaxially with the case 11 and the axis of rotation C1.

[0036] The carrier 14 comprises a disc-shaped end plate portion 30 positioned axially toward the boom 108, a disc-shaped base plate portion 32 positioned axially toward the support portion 107, and three cylindrical column portions 33 integrally molded with the base plate portion 32 and protruding from the base plate portion 32 toward the end plate portion 30. The column portions 33 are arranged at equal intervals in the circumferential direction. The column portions 33 and the end plate portions 30 are fastened together by bolts 34 with the tip surfaces of the column portions 33 overlapping the end plate portions 30. In this state, a space having a predetermined width in the axial direction is formed between the base plate portion 32 and the end plate portions 30.

[0037] The column portion 33 has a bolt fastening hole 33a into which a bolt 34 is tightened. The bolt 34, inserted into the bolt insertion hole 30a from the opposite side of the column portion 33 with the end plate portion 30 in between, is tightened into the bolt fastening hole 33a of the column portion 33. Slightly radially inward from the bolt 34, a pin 36 is provided to position the end plate portion 30 relative to the base portion 32. The pin 36 is positioned to straddle the column portion 33 and the end plate portion 30. Furthermore, the column portion 33 does not necessarily have to be formed integrally with the base portion 32. In this case, the column portion 33 is fastened to the base portion 32. Also, the column portion 33 is not limited to a cylindrical shape. It is sufficient that the column portion 33 forms a space with a predetermined width in the axial direction between the base portion 32 and the end plate portion 30.

[0038] The side surface 107a of the support portion 107 is superimposed on the surface 32c of the base plate portion 32 opposite to the end plate portion 30. In this state, the base plate portion 32 is fastened and fixed to the side surface 107a of the support portion 107 by bolts 122. Furthermore, multiple through holes 30c and 32b are formed in the end plate portion 30 and the base plate portion 32, into which the crankshaft 46 of the reduction output unit 18, which will be described later, is inserted (for example, three in this embodiment). The through holes 30c and 32b are arranged at equal intervals in the circumferential direction. Furthermore, through holes 30b and 32a are formed in the radial center of the end plate portion 30 and the base plate portion 32, extending axially. The input shaft 16 is inserted into these through holes 30b and 32a. The input shaft 16 is positioned coaxially with the case 11 and the rotation axis C1.

[0039] The base end 16a of the input shaft 16 on the electric motor 22 side is coupled to the motor shaft 22a. As a result, the input shaft 16 rotates together with the motor shaft 22a. The tip 16b of the input shaft 16 on the side opposite to the electric motor 22 (the side facing the support portion 107) is located within the through hole 32a of the base plate portion 32. A drive gear 42, which is an external gear, is integrally provided on the tip 16b of the input shaft 16.

[0040] <Deceleration output section> The reduction output unit 18 that rotates the carrier 14 rotates the carrier 14 at a rotational speed reduced by a predetermined ratio to the rotational speed of the input shaft 16. The reduction output unit 18 comprises a plurality of transmission gears 44 (for example, three in this embodiment) that mesh with the drive gear 42, a plurality of crankshafts 46 (for example, three in this embodiment) with one end fixed to the transmission gears 44, and a first external gear (an example of an external gear member according to the claim) 48a and a second external gear (an example of an external gear member according to the claim) 48b that oscillate in conjunction with the rotation of the crankshafts 46.

[0041] Since a transmission gear 44 is fixed to one end of the crankshaft 46, the rotation of the motor shaft 22a is transmitted to the crankshaft 46 via the transmission gear 44. The crankshaft 46 is positioned parallel to the input shaft 16. That is, the crankshaft 46 rotates around a crank rotation axis (an example of a second rotation axis according to the claim) C20, which is parallel to the rotation axis C1. The crankshaft 46 is rotatably supported on the end plate portion 30 via a first crank bearing 51. The crankshaft 46 is also rotatably supported on the base portion 32 via a second crank bearing 52. The first crank bearing 51 and the second crank bearing 52 are, for example, tapered roller bearings.

[0042] At the axial center of the crankshaft 46, a first eccentric portion 46a and a second eccentric portion 46b are formed, eccentric to the axis of the crankshaft 46. The first eccentric portion 46a and the second eccentric portion 46b are arranged adjacent to each other in the axial direction between the first crank bearing 51 and the second crank bearing 52. The first eccentric portion 46a is adjacent to the first crank bearing 51. The second eccentric portion 46b is adjacent to the second crank bearing 52. Furthermore, the first eccentric portion 46a and the second eccentric portion 46b are offset from each other by a phase angle.

[0043] These crankshafts 46 are inserted into the through holes 30c and 32b of the end plate portion 30 and the base plate portion 32, respectively. In other words, the crankshafts 46 are also arranged at equal intervals in the circumferential direction, similar to the through holes 30c and 32b.

[0044] Furthermore, a first roller bearing 55a is attached to the first eccentric portion 46a of the crankshaft 46. A second roller bearing 55b is attached to the second eccentric portion 46b. The first roller bearing 55a is, for example, a cylindrical roller bearing. The first roller bearing 55a has a plurality of rollers 56 and a cage 57 that holds the plurality of rollers 56. The second roller bearing 55b has the same configuration as the first roller bearing 55a, so a detailed explanation of it is omitted. The first external gear 48a and the second external gear 48b are oscillating and rotating in conjunction with the rotation of the crankshaft 46 via each of the roller bearings 55a and 55b.

[0045] The first external gear 48a and the second external gear 48b are positioned in the space between the base portion 32 and the end plate portion 30 of the carrier 14. The first external gear 48a and the second external gear 48b have external teeth 49a and 49b that mesh with the internal teeth 24 of the case 11. The first external gear 48a and the second external gear 48b are formed with a first through hole 48c into which the input shaft 16 is inserted, a second through hole 48d into which the column portion 33 is inserted, and a third through hole 48e into which the eccentric portions 46a and 46b of the crankshaft 46 are inserted.

[0046] The first eccentric portion 46a and the first roller bearing 55a of the crankshaft 46 are inserted into the third through hole 48e of the first external gear 48a. The second eccentric portion 46b of the crankshaft 46 and the second roller bearing 55b are inserted into the third through hole 48e of the second external gear 48b. As a result, as the first and second eccentric portions 46b oscillate due to the rotation of the crankshaft 46, the first external gear 48a and the second external gear 48b oscillate while meshing with the internal teeth 24 of the case 11.

[0047] A first washer 59 is provided between the first crank bearing 51 and the first roller bearing 55a. The first washer 59 is fitted onto the outer circumferential surface of the crankshaft 46. The first washer 59 is positioned on the end face of the first eccentric portion 46a opposite to the second eccentric portion 46b. A second washer 60 is provided between the second crank bearing 52 and the second roller bearing 55b. The second washer 60 is fitted onto the outer circumferential surface of the crankshaft 46. The second washer 60 is positioned on the end face of the second eccentric portion 46b, which is opposite to the first eccentric portion 46a. The outer diameter of the second washer 60 is the same as the outer diameter of the first washer 59.

[0048] <Arrangement of the second and third reduction mechanisms> As described above, the basic configuration of the second reduction mechanism 2 and the third reduction mechanism 3 is the same as that of the first reduction mechanism 1. However, the mounting orientation of the second reduction mechanism 2 and the third reduction mechanism 3 is different from that of the first reduction mechanism 1. The arrangement of the second reduction mechanism 2 and the third reduction mechanism 3 will be described below with reference to Figure 3, based on Figure 2.

[0049] First, let's explain the arrangement of the second reduction mechanism 2. The reference numerals for the second reduction mechanism 2 and the third reduction mechanism 3, as well as the reference numerals for the bolts used to fix these reduction mechanisms 2 and 3, will be the same as those used for the first reduction mechanism 1 described above. In the second reduction gear mechanism 2, the electric motor 22 is fastened and fixed to the second side surface 108d of the boom 108 by bolts 120. That is, the electric motor 22 of the second reduction gear mechanism 2 protrudes from the boom 108 toward the control room 106.

[0050] Furthermore, the first side surface 108c of the boom 108 is superimposed on the end face 11b of the outer flange portion 11a, which is integrally molded with the case 11 of the second reduction mechanism 2. The case 11 is then fastened and fixed to the boom 108 by bolts 121. Furthermore, the first side surface 109c of the arm 109 is superimposed on the surface 32c of the base plate portion 32 in the second reduction mechanism portion 2 that is opposite to the end plate portion 30. In this state, the base plate portion 32 is fastened and fixed to the first side surface 109c of the arm 109 by bolts 122.

[0051] Next, the arrangement of the third reduction mechanism 3 will be described. In the third reduction gear mechanism 3, the electric motor 22 is fastened and fixed by bolts 120 to the first side surface 112a on the control room 106 side of the mounting stay 112 provided on the bucket 110. That is, the electric motor 22 of the third reduction gear mechanism 3 protrudes from the arm 109 toward the control room 106 side.

[0052] Furthermore, the outer flange portion 11a, which is integrally molded with the case 11 of the third reduction mechanism 3, has the second side surface 112b of the mounting stay 112, opposite to the first side surface 112a of the mounting stay 112, superimposed on the end face 11b of the bucket 110 on the mounting stay 112 side. The case 11 is then fastened and fixed to the bucket 110 by bolts 121. Furthermore, the first side surface 109c of the arm 109 is superimposed on the surface 32c of the base plate portion 32 in the third reduction mechanism portion 3 that is opposite to the end plate portion 30. In this state, the base plate portion 32 is fastened and fixed to the first side surface 109c of the arm 109 by bolts 122.

[0053] Here, the axis of the motor shaft 22a in the second reduction mechanism 2 coincides with the rotation axis C2 of the arm 109 relative to the boom 108. The axis of the motor shaft 22a in the third reduction mechanism 3 coincides with the rotation axis C3 of the bucket 110 relative to the arm 109. In other words, each reduction mechanism 1 to 3 is arranged so that their respective rotation axes C1 to C3 are parallel.

[0054] <Operation of the working part> Next, the operation of the working part 104 will be described. First, we will explain the case when the first reduction gear mechanism 1 is driven. When the electric motor 22 of the first reduction gear 1 is driven, the input shaft 16 is driven in conjunction with the motor shaft 22a. As a result, the rotation of the input shaft 16 causes the transmission gear 44 to rotate via the drive gear 42. Consequently, the crankshaft 46 rotates together with the transmission gear 44 around the crank rotation axis C20.

[0055] As the crankshaft 46 rotates, the first external gear 48a rotates while meshing with the internal teeth 24 as the first eccentric part 46a oscillates, and the second external gear 48b rotates while meshing with the internal teeth 24 as the second eccentric part 46b oscillates. In other words, the crankshaft 46 rotates around the crank rotation axis C20 and revolves around the rotation axis C1.

[0056] In this embodiment, the column portion 33 that passes through the second through-hole 48d of both external gears 48a and 48b is fixed in place together with the base portion 32. As a result, the carrier 14 rotates relative to the case 11 at a reduced rotational speed compared to the input shaft 16. Here, since the base portion 32 of the carrier 14 is fastened and fixed to the support portion 107, the case 11 rotates relative to the carrier 14 at a reduced rotational speed compared to the input shaft 16. The boom 108 is fastened and fixed to the case 11 by bolts 121, so the boom 108 rotates around the rotation axis C1. In other words, the boom 108 swings relative to the slewing body 103.

[0057] When the electric motors 22 of the second reduction mechanism 2 and the third reduction mechanism 3 are driven, the arm 109 and bucket 110 are swung in the same manner as described above. That is, when the electric motor 22 of the second reduction mechanism 2 is driven, the arm 109 is swung relative to the boom 108. When the electric motor 22 of the third reduction mechanism 3 is driven, the bucket 110 is swung relative to the arm 109.

[0058] Here, when the boom 108 is swung by the first reduction mechanism 1, the weights of the arm 109 and the second reduction mechanism 2 connected to the other longitudinal end 108b of the boom 108, and the weights of the bucket 110 and the third reduction mechanism 3 connected to the other longitudinal end 109b of the arm 109 also act on it. When the arm 109 is swung by the second reduction mechanism 2, the weights of the bucket 110 and the third reduction mechanism 3 connected to the other longitudinal end 109b of the arm 109 also act on it. When the bucket 110 is swung by the third reduction mechanism 3, only the weight of the bucket 110 acts on it.

[0059] Therefore, of the three reduction mechanisms 1 to 3, the transmission torque capacity of the first reduction mechanism 1 is set to be the largest. The transmission torque capacity of the second reduction mechanism 2 is set to be smaller than that of the first reduction mechanism 1. Of the three reduction mechanisms 1 to 3, the transmission torque capacity of the third reduction mechanism 3 is set to be the smallest, and the transmission torque capacity of the third reduction mechanism 3 is smaller than that of the second reduction mechanism 2. In other words, of the three reduction mechanisms 1 to 3, the first reduction mechanism 1 is the largest in size and also the heaviest. The second reduction mechanism 2 is smaller in size than the first reduction mechanism 1. Also, the weight of the second reduction mechanism 2 is lighter than that of the first reduction mechanism 1. Of the three reduction mechanisms 1 to 3, the third reduction mechanism 3 is the smallest in size and also the lightest in weight.

[0060] As described above, in this embodiment, the boom 108, arm 109, and bucket 110, which are mounted on the slewing body 103 of the self-propelled shovel 100, are connected via reduction gear mechanisms 1 to 3. Therefore, the boom 108, arm 109, and bucket 110 can be swung by each reduction gear mechanism 1 to 3 alone, that is, by the rotation mechanism alone. As a result, the structure of the shovel 100 can be reliably simplified as the shovel 100 is electrified.

[0061] Furthermore, the reduction unit 10 of the reduction mechanism units 1 to 3 comprises a cylindrical case 11, a carrier 14 positioned radially inside the case 11, an input shaft 16 that provides a driving force to rotate the carrier 14, and a reduction output unit 18 that rotates the carrier 14 at a rotational speed reduced by a predetermined ratio to the rotational speed of the input shaft 16. The reduction output unit 18 comprises a plurality of crankshafts 46 and a first external gear 48a and a second external gear 48b that oscillate in conjunction with the rotation of the crankshafts 46. As a result, high output can be obtained with a high reduction ratio by the reduction mechanism units 1 to 3, allowing the boom 108, arm 109, and bucket 110 to operate smoothly while miniaturizing the reduction mechanism units 1 to 3.

[0062] Furthermore, the carriers 14 of the reduction gear sections 1 to 3 are rotatably supported by the case 11 by a pair of main bearings 26 arranged at intervals in the axial direction. In other words, the main bearings 26 provided in the reduction gear sections 1 to 3 allow the arm 109 to be rotatably supported relative to the boom 108, and also allow the bucket 110 to be rotatably supported relative to the arm 109. Therefore, there is no need for bearings to rotatably support each part separately from the reduction gear sections 1 to 3, and the structure of the shovel 100 can be further simplified.

[0063] Furthermore, in the second reduction mechanism section 2, the electric motor 22 is attached to the boom 108 side. When the arm 109 is swung relative to the boom 108, the boom 108 remains in a fixed position while the arm 109 rotates. In other words, by attaching the electric motor 22 to the boom 108 side, which does not move and remains in a fixed position, the weight of the electric motor 22 does not affect the swinging of the arm 109, and the inertia when swinging the arm 109 can be reduced.

[0064] Furthermore, in the second reduction mechanism 2, the electric motor 22 protrudes from the boom 108 toward the control room 106, making it easy to see the electric motor 22 of the second reduction mechanism 2 from the control room 106. Therefore, when the operator operates the shovel 100, there is no risk of accidentally hitting the electric motor 22 of the second reduction mechanism 2, thus reducing damage to the electric motor 22. The same applies to the electric motor 22 of the third reduction mechanism 3. Since the electric motor 22 of the third reduction mechanism 3 also protrudes from the arm 109 toward the control room 106, damage to the electric motor 22 can be suppressed.

[0065] Furthermore, the transmission torque capacity, size, and weight of each reduction mechanism 1 to 3 are varied according to their mounting location. In other words, the transmission torque capacity, size, and weight of each reduction mechanism 1 to 3 are reduced as they move towards the front of the working section 104. As a result, the working section 104 as a whole can be made smaller without unnecessarily increasing the size of each reduction mechanism 1 to 3.

[0066] Each of the reduction gear mechanisms 1 to 3 is arranged so that their respective rotation axes C1 to C3 are parallel. As a result, the boom 108, arm 109, and bucket 110 that constitute the working section 104 can be swung in the same direction (forward and backward direction perpendicular to the rotation axes C1 to C3), thereby improving the operability of the shovel 100.

[0067] The boom 108, which constitutes the working section 104, is attached to the side surface 107a of the support section 107 on the side opposite to the operating chamber 106 in the thickness direction. The arm 109 is attached to the first side surface 108c of the boom 108 on the side opposite to the operating chamber 106 in the short direction. The bucket 110 is attached to the first side surface 109c of the arm 109 on the operating chamber 106 side in the short direction. In other words, the arm 109 is positioned on the side opposite to the operating chamber 106, with the boom 108 in between. As a result, the operator feels less pressure from the arm 109 compared to when the arm 109 is positioned on the operating chamber 106 side. This improves the operability of the shovel 100.

[0068] In the above-described embodiment, the reduction gears 1 to 3 were explained in the case where the electric motor 22 is fastened and fixed to the case 11 via the mounting stays 112 of the boom 108 and the bucket 110. However, the invention is not limited to this, and the electric motor 22 may also be fastened and fixed to the carrier 14. In this case, the mounting stays 112 of the boom 108 and the bucket 110 are fixed to the carrier 14, and the electric motor 22 is fastened and fixed to the carrier 14 via the boom 108 and the mounting stays 112. On the other hand, the support part 107 and the arm 109 are fastened and fixed to the case 11.

[0069] [First variation] Next, a first modified example of the embodiment will be described based on Figure 5. Figure 5 is a schematic diagram of the shovel 100 in the first modified example, viewed from above. Components identical to those in the embodiment are denoted by the same reference numerals and their descriptions are omitted (the same applies to the following modified examples). The differences between the above-described embodiment and the modified form are that the boom 108, arm 109, and bucket 110 are in different positions, and the orientation of the second reduction mechanism 2 and the third reduction mechanism 3 is different.

[0070] Specifically, in the first modified example, the arm 109 is attached to the second side 108d of the boom 108 on the side of the control room 106 in the short direction. The bucket 110 is attached to the second side 109d of the arm 109 on the side opposite to the control room 106 in the short direction.

[0071] In the second reduction gear mechanism 2, the electric motor 22 is fastened and fixed to the first side surface 108c of the boom 108 by bolts 120. That is, the electric motor 22 of the second reduction gear mechanism 2 protrudes from the boom 108 toward the opposite side from the control room 106. Furthermore, the second side surface 108d of the boom 108 is superimposed on the end face 11b of the outer flange portion 11a, which is integrally molded with the case 11 of the second reduction mechanism 2. The case 11 is then fastened and fixed to the boom 108 by bolts 121. Furthermore, the second side surface 109d of the arm 109 is superimposed on the surface 32c of the base plate portion 32 in the second reduction mechanism portion 2, which is opposite to the end plate portion 30. In this state, the base plate portion 32 is fastened and fixed to the second side surface 109d of the arm 109 by bolts 122.

[0072] On the other hand, in the third reduction gear mechanism 3, the electric motor 22 is fastened and fixed to the second side surface 112b of the mounting stay 112 provided on the bucket 110 by bolts 120. That is, the electric motor 22 of the third reduction gear mechanism 3 protrudes from the arm 109 toward the opposite side from the control room 106. Furthermore, the outer flange portion 11a, which is integrally molded with the case 11 of the third reduction mechanism 3, has the first side surface 112a of the mounting stay 112 superimposed on the end face 11b of the bucket 110 on the mounting stay 112 side. The case 11 is then fastened and fixed to the bucket 110 by bolts 121. Furthermore, the second side surface 109d of the arm 109 is superimposed on the surface 32c of the base plate portion 32 in the third reduction mechanism portion 3, which is opposite to the end plate portion 30. In this state, the base plate portion 32 is fastened and fixed to the second side surface 109d of the arm 109 by bolts 122.

[0073] Therefore, according to the first modification described above, the same effects as those of the embodiment described above are achieved. Furthermore, the arm 109 is attached to the second side surface 108d of the boom 108 on the side of the control room 106, in the short direction. The bucket 110 is attached to the second side surface 109d of the arm 109 on the side opposite to the control room 106, in the short direction. In the second reduction mechanism 2, the electric motor 22 protrudes from the boom 108 toward the side opposite to the control room 106. In the third reduction mechanism 3, the electric motor 22 protrudes from the arm 109 toward the side opposite to the control room 106. This prevents the electric motor 22 from obstructing the view from the control room 106. Thus, the operability of the shovel 100 can be improved.

[0074] [Second variation] Next, a second modified example of the embodiment will be described based on Figure 6. Figure 6 is a schematic diagram of the working part 104 in the second modified example, viewed from above. As shown in Figure 6, the difference between the embodiment and the second modified example is that in the embodiment, the working part 104 has an arm 109 positioned on the first side surface 108c of the boom 108 and the arm 109 is cantilevered relative to the boom 108, whereas in the second modified example, the arm 109 is double-supported relative to the boom 108. Also, in the embodiment, the working part 104 has a bucket 110 positioned on the first side surface 109c of the arm 109 and the bucket 110 is cantilevered relative to the arm 109, whereas in the second modified example, the bucket 110 is double-supported relative to the arm 109.

[0075] Specifically, the second modified example includes two support parts 207a and 207b (first support part 207a and second support part 207b) for supporting the boom 108. The two support parts 207a and 207b are located on both sides 108c and 108d of the boom 108 on the longitudinal end 108a side. The longitudinal end 108a of the boom 108 is rotatably supported (double-supported) by the two support parts 207a and 207b. Of the two support parts 207a and 207b, the electric motor 22 of the first reduction mechanism 1 is fixed to the second support part 207b, which is located on the opposite side of the boom 108 from the control room 106 (right side in Figure 6). The reduction section 10 of the first reduction mechanism 1 is located between the second support part 207b and the boom 108.

[0076] Two boom support sections 208a and 208b (first boom support section 208a and second boom support section 208b) are provided projecting along the longitudinal direction of the boom 108 from the other longitudinal end 108b of the boom 108. One longitudinal end 109a of the arm 109 is positioned between the two boom support sections 208a and 208b. The longitudinal end 109a of the arm 109 is rotatably supported (double-supported) by the two boom support sections 208a and 208b. The electric motor 22 of the second reduction gear section 2 is fixed to one of the two boom support sections 208a and 208b (in Figure 6, the second boom support section 208b on the right side of the figure). Furthermore, the reduction unit 10 of the second reduction mechanism 2 is positioned between either of the two boom support sections 208a and 208b (in Figure 6, the second boom support section 208b on the right side of the figure) and the arm 109. Alternatively, the electric motor 22 may be fixed to the first boom support section 208a on the left side of Figure 6, and the reduction unit 10 may be positioned between the first boom support section 208a and the arm 109.

[0077] Two bucket support sections 212a and 212b (first bucket support section 212a and second bucket support section 212b) are provided on the mounting stay 112 of the bucket 110, protruding along the longitudinal direction of the arm 109. The other end 109b in the longitudinal direction of the arm 109 is positioned between the two bucket support sections 212a and 212b. The two bucket support sections 212a and 212b are rotatably supported at the other end 109b in the longitudinal direction of the arm 109. The electric motor 22 of the third reduction mechanism 3 is fixed to one of the two bucket support sections 212a and 212b (in Figure 6, the second bucket support section 212b on the right side of the figure). The reduction section 10 of the third reduction mechanism 3 is positioned between one of the two bucket support sections 212a and 212b (in Figure 6, the second bucket support section 212b on the right side of the figure) and the arm 109. In addition, the electric motor 22 may be fixed to the first bucket support part 212a on the left side in Figure 6, and the reduction unit 10 may be positioned between the first bucket support part 212a and the arm 109.

[0078] Therefore, the second modification described above produces the same effects as the embodiment described above. Furthermore, the arm 109 is supported by both sides of the boom 108, and the bucket 110 is also supported by both sides of the arm 109. Therefore, compared to the previously described embodiment, the strength of the connection between the support parts 207a, 207b and the boom 108, the connection between the boom 108 (boom support parts 208a, 208b) and the arm 109, and the connection between the arm 109 and the bucket 110 (bucket support parts 212a, 212b) can be increased. In addition, the operation of the working part 104 can be stabilized.

[0079] It should be noted that the present invention is not limited to the embodiments and modifications described above, but also includes various modifications to the embodiments described above, without departing from the spirit of the present invention. For example, the above embodiments and their modifications described the case where the construction machine is an excavator 100. However, it is not limited to this, and the above reduction mechanism configuration 1 to 3 can be adopted for various construction machines such as bulldozers, motor graders, forklifts, and wheel loaders. Depending on the application of the construction machine, various tools (such as hooks and other attachments) can be attached in place of the bucket 110.

[0080] The embodiments and modifications described above describe a case in which a self-propelled vehicle 101 and a slewing body 103 provided on the upper part of the vehicle 101 via a slewing mechanism 102 and slewing relative to the vehicle 101 are provided. Then, a case in which an operating part 104 is provided on such a slewing body 103 was described. However, the invention is not limited to this, and any self-propelled vehicle body (main body) will suffice, as long as the operating part 104 is provided on this vehicle body.

[0081] In the embodiments and modifications described above, the reduction unit 10 of the reduction mechanism units 1 to 3 was described as comprising a cylindrical case 11, a carrier 14 arranged radially inside the case 11, an input shaft 16 that provides a driving force to rotate the carrier 14, and a reduction output unit 18 that rotates the carrier 14 at a rotational speed reduced by a predetermined ratio to the rotational speed of the input shaft 16. The reduction output unit 18 was described as a so-called eccentric oscillating type reduction unit comprising a plurality of crankshafts 46 and a first external gear 48a and a second external gear 48b that oscillate in conjunction with the rotation of the crankshafts 46. However, it is not limited to this, and the reduction unit 10 may be an eccentric oscillating type reduction unit comprising a first member (e.g., case 11) and a second member (e.g., carrier 14) that rotate relative to each other around the same rotation axis C1, and at least one crankshaft (e.g., crankshaft 46) positioned between the first member and the second member, receiving power from the drive unit and rotating about a second rotation axis along the first rotation axis, and which reduces the rotation of the crankshaft and transmits it to the second member, thereby reducing the rotation of the second member relative to the first member.

[0082] In the embodiments and modifications described above, the case where each reduction mechanism 1 to 3 is arranged so that its rotation axes C1 to C3 are parallel was explained. However, it is not limited to this, and the rotation axes C1 to C3 do not have to be perfectly parallel. The rotation axes of each reduction mechanism 1 to 3 only need to be aligned in the same direction. In the embodiments and modifications described above, the case in which the working part 104 consists of a boom 108, an arm 109, and a bucket 110 has been explained. However, it is not limited to this, and it is sufficient that at least a part of the working part 104 is rotatably (oscillatingly) provided via reduction mechanism parts 1 to 3. [Explanation of symbols]

[0083] 1...First reduction mechanism (reduction mechanism, first reduction mechanism), 2...Second reduction mechanism (reduction mechanism, second reduction mechanism), 3...Third reduction mechanism (reduction mechanism, third reduction mechanism), 10...Reduction unit, 11...Case (first member), 14...Carrier (second member), 22...Electric motor (drive unit), 26...Main bearing (bearing), 46...Crankshaft, 48a...First external gear (external gear), 48b...Second external gear (external gear), 49a, 49b...External teeth, 100...Shovel (construction machine), 101...Traveling body (main body), 103...Slewing body (main body), 104...Operating part, 106...Operating room, 107...Support part, 1 07a...side, 108...boom, 108c,109c...first side (side), 108d,109d...second side (side), 109...arm, 110...bucket (attachment), 112...mounting stay, 112a...first side, 112b...second side, 207a...first support (support), 207b...second support (support), 208a...first boom support (boom), 208b...second boom support (boom), 212a...first bucket support (attachment), 212b...second bucket support (attachment), C1~C3...rotation axis (first rotation axis), C20...crank rotation axis (second rotation axis)

Claims

1. The main body is self-propelled, The operating part attached to the main body, A reduction mechanism is provided in a part of the operating part and rotates the part, Equipped with, The aforementioned reduction mechanism section is The deceleration section, A drive unit that drives the reduction unit, Equipped with Construction machinery.

2. The aforementioned deceleration unit is A first member and a second member that rotate relative to each other around the same first axis of rotation, Displaced between the first member and the second member, at least one crankshaft that receives power from the drive unit and rotates about a second rotation axis along the first rotation axis, Equipped with, This is an eccentric oscillating type reduction unit that reduces the rotation of the crankshaft and transmits it to the second member, thereby reducing the rotation of the second member relative to the first member. The construction machine according to claim 1.

3. Having multiple crankshafts, The external tooth member has external teeth that oscillate around the first rotation axis by the crankshaft, The first member is a case having internal teeth that mesh with the external teeth, The second member is a carrier that rotatably supports the crankshaft and is rotatably supported by the first member via a bearing, and rotates at a reduced speed relative to the case by the crankshaft. The construction machine according to claim 2.

4. The drive unit is fixed to the first member. The construction machine according to claim 2 or claim 3.

5. The aforementioned working part is, A boom rotatably supported on the main body, An arm is rotatably supported on the opposite side of the main body of the boom, An attachment rotatably supported on the opposite side of the arm from the boom, Includes, The boom is provided on the main body via the first reduction mechanism, The arm is provided on the boom via a second reduction mechanism having a smaller torque transmission capacity than the first reduction mechanism. The attachment is provided on the arm via a third reduction mechanism, which transmits less torque than the second reduction mechanism. A construction machine according to any one of claims 1 to 4.

6. The aforementioned working part is, A boom rotatably supported on the main body, An arm is rotatably supported on the opposite side of the main body of the boom, An attachment rotatably supported on the opposite side of the arm from the boom, Includes, The boom is provided on the main body via the first reduction mechanism, The boom is provided with the arm via a second reduction mechanism having a weight lighter than the weight of the first reduction mechanism. The attachment is provided on the arm via a third reduction mechanism, which is lighter in weight than the second reduction mechanism. A construction machine according to any one of claims 1 to 4.

7. Each of the aforementioned reduction gear mechanisms is arranged such that the rotation axes of the reduction gears are aligned in the same direction. A construction machine according to any one of claims 1 to 6.

8. The main body has a support portion that rotatably supports the working portion, The aforementioned working part is, A boom whose side is rotatably supported by the aforementioned support, An arm is rotatably supported on the side of the boom opposite to the main body, An attachment rotatably supported on the opposite side of the arm from the boom, including A construction machine according to any one of claims 1 to 7.

9. The aforementioned working part is, The main body is rotatably supported and has a boom that is long in one direction, An arm is rotatably supported on the side of the boom opposite to the main body and on the shorter side of the boom, An attachment is rotatably supported on the same side of the arm as the side on which the boom is positioned, on the side opposite to the boom of the arm, including A construction machine according to any one of claims 1 to 8.

10. The main body is, A self-propelled vehicle, A rotating body that rotates relative to the aforementioned traveling body, An operating room provided on the rotating body and arranged horizontally alongside the operating part, Includes, The drive unit is located on the side of the operating unit facing the control chamber. A construction machine according to any one of claims 1 to 9.

11. The main body is, A self-propelled vehicle, A rotating body that rotates relative to the aforementioned traveling body, An operating room provided on the rotating body and arranged horizontally alongside the operating part, Includes, The drive unit is located on the side of the operating unit opposite to the operating chamber. A construction machine according to any one of claims 1 to 9.

12. The main body is self-propelled, A reduction mechanism having a reduction unit and a drive unit that drives the reduction unit, A boom is rotatably supported on the main body via the first reduction mechanism, An arm is rotatably supported on the boom via a second reduction mechanism having a smaller torque transmission capacity than the first reduction mechanism, An attachment is rotatably supported on the arm via a third reduction mechanism having a smaller transmission torque than the second reduction mechanism, Equipped with Construction machinery.

13. Each of the aforementioned reduction gear mechanisms is arranged such that the rotation axes of the reduction gears are aligned in the same direction. The construction machine according to claim 12.

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