Crawler drive unit and construction machine

Abstract

To provide a crawler drive unit which enables reduction of a possibility that a motor contacts with sand or rocks etc., and to provide a construction machine.SOLUTION: A crawler drive unit 1 of an embodiment includes: a speed reduction mechanism 4 which is provided at a travel part 102 which causes a vehicle main body 101 to travel and transmits driving force to a crawler provided at the travel part 102; a transmission mechanism 3 which transmits the driving force to the speed reduction mechanism 4; and an electric motor 2 which applies rotational force to the speed reduction mechanism 4. A motor shaft 7 of the electric motor 2 is located above a rotation axis Jn of an input shaft 16 of the speed reduction mechanism 4.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a crawler drive unit and a construction machine.

Background Art

[0002] As a traveling unit that enables the vehicle body to travel on rough roads, a construction machine is provided with a crawler instead of wheels used in passenger cars and the like. The crawler is meshed with a drive wheel (sprocket) that rotates around a rotation axis. As a drive unit for rotationally driving the drive wheel, a hydraulic drive unit using a hydraulic motor that can easily obtain a large rotational torque is often used. The hydraulic drive unit includes, in addition to the hydraulic motor, a hydraulic pump for supplying hydraulic oil to the hydraulic motor and an engine for driving the hydraulic pump. The hydraulic oil discharged from the hydraulic pump is supplied to the hydraulic motor through pipes routed through the construction machine.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, in recent years, there has been an increasing demand to use an electric drive unit instead of a hydraulic drive unit for the purpose of simplifying construction machines. The electric drive unit includes a battery that replaces the engine, an electric motor driven by the power of the battery, and the like. The electric drive unit eliminates the need for a hydraulic pump and also eliminates the need to route pipes.

[0005] Here, when comparing an electric motor and a hydraulic motor of the same size, the rotational torque of the electric motor tends to be smaller than that of the hydraulic motor. For this reason, when using an electric drive unit, the size of the electric motor is increased, and a speed reduction mechanism that decelerates and outputs the rotation of the electric motor is used in combination with the electric motor.

[0006] The speed reduction mechanism has a plurality of gears rotatably provided in a housing. Some of the speed reduction mechanisms provided in the traveling unit use the housing as an output part. Under such a configuration, in order to prevent the drive unit from being damaged by earth and sand, rock, etc. during the traveling of the construction machine, it is desirable to prevent the electric drive unit from protruding from the traveling unit as much as possible. For this reason, it is conceivable to house the speed reduction mechanism coaxially with the drive wheel inside the drive wheel. Then, the drive wheel is rotated integrally with the housing (output part).

[0007] However, if simply trying to replace the hydraulic drive unit with an electric drive unit, the electric motor and the speed reduction mechanism will be arranged in the space where the hydraulic motor was originally arranged. For this reason, even if the speed reduction mechanism can be housed within the width in the vehicle width direction of the traveling unit (within the width of the sprocket), the electric motor will protrude in the vehicle width direction from the traveling unit. As a result, during the traveling of the construction machine, the electric motor may come into contact with earth and sand, rock, etc., and this electric motor may be damaged. In particular, when the speed reduction mechanism and the electric motor are arranged at approximately the same height, the position of the electric motor from the road surface becomes closer. Accordingly, the possibility of the electric motor being damaged increases.

[0008] The present invention provides a crawler drive unit and a construction machine capable of reducing the possibility of an electric motor coming into contact with earth and sand, rock, etc.

Means for Solving the Problem

[0009] A crawler drive unit according to one aspect of the present invention is provided in a traveling section that travels a vehicle body main body, and includes a speed reduction mechanism that transmits a driving force to a crawler provided in the traveling section, a transmission mechanism that transmits the driving force to the speed reduction mechanism, and an electric motor that applies a rotational force to the transmission mechanism. A motor shaft of the electric motor is located above a rotational axis of an input section to which the driving force from the transmission mechanism of the speed reduction mechanism is input.

[0010] By configuring in this way, the position of the electric motor can be positioned above the speed reduction mechanism. For this reason, when a crawler drive unit including the electric motor and the speed reduction mechanism is provided on a crawler, even when the electric motor protrudes in the vehicle width direction from a roller, the position of the electric motor can be separated from the road surface as much as possible. Therefore, the possibility that the electric motor comes into contact with earth and sand, rock, etc. can be reduced.

[0011] In the above configuration, the rotational axis of the motor shaft and the rotational axis of the input section may be parallel.

[0012] In the above configuration, the electric motor may be provided to protrude in the vehicle width direction of the vehicle body main body from the speed reduction mechanism.

[0013] In the above configuration, the transmission mechanism may be formed by meshing a plurality of gears.

[0014] In the above configuration, the transmission mechanism may decelerate the rotation of the motor shaft and transmit it to the input section.

[0015] In the above configuration, the entire electric motor may be located above the rotational axis of the input section.

[0016] In the above configuration, the entire electric motor may be located above the bottom surface of the vehicle body main body.

[0017] In the above configuration, at least a part of the speed reduction mechanism may be housed within the width in the vehicle width direction of the vehicle body main body in the crawler.

[0018] A crawler drive unit according to another aspect of the present invention is provided in a traveling unit that travels the vehicle body main body, and includes a speed reduction mechanism that transmits a driving force to a crawler provided in the traveling unit, a transmission mechanism that transmits a driving force to the speed reduction mechanism, and an electric motor that protrudes from the speed reduction mechanism in the vehicle width direction of the vehicle body main body and applies a rotational force to the speed reduction mechanism. The transmission mechanism decelerates the rotation of the motor shaft of the electric motor and transmits it to the speed reduction mechanism, and the entire electric motor is located above the bottom surface of the vehicle body main body.

[0019] By configuring in this way, the position of the electric motor can be positioned above the speed reduction mechanism. Therefore, when providing a crawler drive unit including an electric motor and a speed reduction mechanism to a crawler, even when the electric motor protrudes in the vehicle width direction from a roller, the position of the electric motor can be separated from the road surface as much as possible. Thus, the possibility of the electric motor coming into contact with earth and sand, rock, etc. can be reduced. In addition to the speed reduction mechanism, the transmission mechanism can also decelerate the rotation of the motor shaft. Therefore, while miniaturizing the crawler drive unit, a high reduction ratio can be obtained, and a high-output crawler drive unit can be provided.

[0020] A crawler drive unit according to another aspect of the present invention is provided in two left and right traveling units that travel the vehicle body main body, and includes two speed reduction mechanisms that transmit a driving force to crawlers provided in each of the traveling units, a transmission mechanism that transmits a driving force to the speed reduction mechanisms, and two electric motors that protrude from the speed reduction mechanisms inside the vehicle width direction of the vehicle body main body and apply a rotational force to the speed reduction mechanisms. The two electric motors are arranged side by side in the front-rear direction of the vehicle body main body.

[0021] By configuring in this way, even when the interval between the left and right crawlers is short, it is possible to prevent interference between the crawler drive units provided on each crawler. In addition, it is not necessary to prepare crawler drive units individually according to the difference in the interval between the left and right crawlers, and the versatility of the crawler drive units can be enhanced.

[0022] With the above configuration, the motor shaft of the electric motor may be positioned above the rotation axis of the input portion to which the driving force from the transmission mechanism of the speed reduction mechanism is input.

[0023] A construction machine according to another aspect of the present invention includes a vehicle body main body, a traveling unit that travels the vehicle body main body, a speed reduction mechanism provided in the traveling unit and transmitting a driving force to a crawler provided in the traveling unit, a transmission mechanism that transmits a driving force to the speed reduction mechanism, and an electric motor that protrudes in the vehicle width direction of the vehicle body main body from the speed reduction mechanism and applies a rotational force to the speed reduction mechanism. The transmission mechanism decelerates the rotation of the motor shaft of the electric motor and transmits it to the speed reduction mechanism, and the entire electric motor is positioned above the bottom surface of the vehicle body main body.

[0024] By configuring in this way, the position of the electric motor with respect to the speed reduction mechanism can be positioned above. Therefore, when providing a crawler drive unit including an electric motor and a speed reduction mechanism to a crawler, even when the electric motor protrudes in the vehicle width direction from a roller, for example, the position of the electric motor can be separated from the road surface as much as possible. Thus, the possibility of the electric motor coming into contact with earth and sand, rock, etc. can be reduced, and a construction machine with high traveling performance can be provided.

Advantages of the Invention

[0025] The above-described crawler drive unit and construction machine can reduce the possibility of the electric motor coming into contact with earth and sand, rock, etc.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Mode for Carrying Out the Invention

[0027] Next, embodiments of the present invention will be described with reference to the drawings.

[0028] [First Embodiment] <Construction Machine> FIG. 1 is a perspective view of a construction machine 100. As shown in FIG. 1, the construction machine 100 performs civil engineering work such as excavating earth and sand or transferring the excavated earth and sand to another vehicle. The construction machine 100 includes a vehicle body main body 101, a traveling unit 102 that travels the vehicle body main body 101, and a crawler drive unit 1 provided in the traveling unit 102 for driving the traveling unit 102. In the following description, the front and rear directions of the traveling direction of the construction machine 100 are referred to as the front-rear direction, and the vehicle width direction of the construction machine 100 that is horizontally orthogonal to the front-rear direction is simply referred to as the vehicle width direction.

[0029] The vehicle body main body 101 includes a revolving body 103 and a lower frame 104 provided below the revolving body 103 for rotatably supporting the revolving body 103. The revolving body 103 includes a cab 105 on which an operator can board and a boom 106 having one end swingably connected to the revolving body 103. Although omitted in FIG. 1, an arm is swingably provided at the other end of the boom 106. Further, a bucket or the like is attached to the end of the arm opposite to the boom 106. Traveling units 102 are provided on both sides in the vehicle width direction of the lower frame 104.

[0030] The traveling unit 102 includes a track frame 107 connected to the lower frame 104 and long in the front-rear direction, an idler (not shown) rotatably provided at the front of the track frame 107, a drive wheel (sprocket) 108 rotatably provided at the rear of the track frame 107, a plurality of idlers (not shown) rotatably provided at the lower part of the track frame 107, and a crawler 109 wound around these idlers, the drive wheel 108, and the idlers. The crawler 109 is made of a metal such as hard rubber or iron. A crawler drive unit 1 is provided to rotationally drive the drive wheel 108.

[0031] <Crawler drive unit> FIG. 2 is a plan view of the traveling unit 102, the lower frame 104, and the crawler drive unit 1 viewed from the front-rear direction. FIG. 3 is a cross-sectional view of the crawler drive unit 1. As shown in FIGS. 2 and 3, the crawler drive unit 1 includes an electric motor 2, a transmission mechanism 3 connected to the electric motor 2, and a reduction mechanism 4 connected to the transmission mechanism 3.

[0032] <Electric motor> The electric motor 2 includes a stator (not shown) fixed within the motor case 5 and a rotor 6 rotatably provided with respect to the stator. The electric motor 2 is driven by the supply of electric power from an external power source (battery) provided in the vehicle body main body 101. As the electric motor 2, various motors that are driven by the supply of electric power, such as a so-called brushed motor or a brushless motor, can be adopted.

[0033] On the outer peripheral surface of the motor case 5, a connector 50 for supplying electric power to the stator (not shown) is provided. An external connector extending from an external power source (not shown) is connected to this connector 50. The connector 50 is provided with a receiving port 50a to which the external connector (not shown) is connected.

[0034] Also, the motor shaft 7 of the rotor 6 is rotatably supported by the motor case 5. A part of the motor shaft 7 protrudes from the motor case 5 along the direction of the rotation axis Jm of the motor shaft 7. The tip end portion 7a of the protruding motor shaft 7 has spline machining on its outer peripheral surface. The transmission mechanism 3 is connected to the tip end portion 7a. The receiving port 50a of the connector 50 provided in the motor case 5 faces the side opposite to the tip end portion 7a of the motor shaft 7.

[0035] Also, the periphery of the portion of the motor shaft 7 that protrudes from the motor case 5 is covered by a cylindrical support case 8. The support case 8 protrudes from the motor case 5 along the direction of the rotation axis Jm to a position in front of the tip end portion 7a of the motor shaft 7. A seal member 9 is provided on the inner peripheral surface of the support case 8 on the side opposite to the motor case 5. The seal member 9 ensures the sealing performance between the support case 8 and the motor shaft 7. The end of the support case 8 on the side opposite to the motor case 5 is also connected to the transmission mechanism 3.

[0036] <Transmission mechanism> The transmission mechanism 3 includes a transmission-side housing 10 and two spur gears 11, 12 (a first spur gear 11 and a second spur gear 12) rotatably housed within the transmission-side housing 10. The transmission-side housing 10 includes a box-shaped housing body 21 with an opening on the side of the electric motor 2, and a closing plate 22 that closes the opening 21a of the housing body 21. A support case 8 is fixed to the closing plate 22. Further, a shaft insertion hole 13 through which the motor shaft 7 is inserted is formed in the closing plate 22. The tip 7a of the motor shaft 7 is inserted into the housing body 21 through this shaft insertion hole 13.

[0037] An operating oil inlet 23 is formed in the outer peripheral wall 21b of the housing body 21. A connection port 14 is formed in the bottom wall 21c of the housing body 21. Further, a transmission-side oil passage 15 that connects the operating oil inlet 23 and the connection port 14 from the outer peripheral wall 21b to the bottom wall 21c is formed in the housing body 21. These operating oil inlet 23, connection port 14, and transmission-side oil passage 15 are for injecting lubricating oil into the speed reduction mechanism 4.

[0038] Two spur gears 11, 12 are housed within the housing body 21 in a meshed state with each other. Among the two spur gears 11, 12, the first spur gear 11 is fitted and fixed to the tip 7a of the motor shaft 7. The motor shaft 7 and the first spur gear 11 rotate integrally due to the spline processing applied to the tip 7a.

[0039] Among the two spur gears 11, 12, the rotation axis Jh of the second spur gear 12 is parallel to the rotation axis Jm of the motor shaft 7 and is offset in the radial direction of the motor shaft 7 (second spur gear 12). The number of teeth of the second spur gear 12 is more than the number of teeth of the first spur gear 11. For this reason, the rotation of the second spur gear 12 is decelerated with respect to the rotation of the first spur gear 11.

[0040] One end 16a of an input shaft 16 (an example of an input portion in the claims) of a speed reduction mechanism 4 is fitted and fixed to a second spur gear 12. Spline machining is performed on this one end 16a, and the second spur gear 12 and the input shaft 16 rotate integrally. A rotation axis Jn of the input shaft 16 coincides with a rotation axis Jh of the second spur gear 12. Here, since the rotation axis Jh of the second spur gear 12 is parallel to a rotation axis Jm of a motor shaft 7, the rotation axis Jn of the input shaft 16 is also parallel to the rotation axis Jm of the motor shaft 7.

[0041] The input shaft 16 is a solid shaft. The input shaft 16 is inserted into the housing main body 21 from the speed reduction mechanism 4 side through a shaft insertion hole 24 formed in a bottom wall 21c of the housing main body 21. A seal member 25 for sealing between the bottom wall 21c of the housing main body 21 and the input shaft 16 and a bearing 26 for rotatably supporting the transmission mechanism 3 side of the input shaft 16 are provided in the shaft insertion hole 24.

[0042] <Speed reduction mechanism> In addition to the input shaft 16, the speed reduction mechanism 4 includes a speed reduction side housing 17 that rotatably supports the input shaft 16, and a multi-stage (two stages in this embodiment) gear mechanism 18A, 18B (a first-stage gear mechanism 18A, a second-stage gear mechanism 18B) connected to the speed reduction side housing 17. In the following description of the speed reduction mechanism 4, the radial direction of the input shaft 16 will be simply referred to as the radial direction.

[0043] The speed reduction side housing 17 is fixed to the bottom wall 21c of the housing main body 21 that constitutes the transmission side housing 10. The speed reduction side housing 17 is integrally formed by a base portion 19 that overlaps the bottom wall 21c of the housing main body 21 and a bearing housing 20 that protrudes from the base portion 19 toward the side opposite to the electric motor 2. On the outer peripheral surface 19a of the base portion 19, a plurality of first fixing seats 27 are integrally formed so as to project radially outward. The first fixing seats 27 are for fixing the crawler drive unit 1 to the traveling portion 102. Further, a through hole 19b through which the input shaft 16 passes is formed in the base portion 19.

[0044] In the bearing housing 20, a recess 28 continuous with the through hole 19b of the base portion 19 is formed. At the bottom of the recess 28 (on the side opposite to the transmission mechanism 3), a shaft insertion hole 29 penetrating the bearing housing 20 in the direction of the rotation axis Jn is formed. Through this shaft insertion hole 29, the other end 16b of the input shaft 16 projects to the side opposite to the transmission mechanism 3. In the shaft insertion hole 29, a bearing 30 for rotatably supporting the input shaft 16 and a seal member 31 for sealing between the bearing housing 20 and the input shaft 16 are provided.

[0045] A parking brake 32 is provided in the recess 28 of the bearing housing 20. The parking brake 32 is for blocking or releasing the rotation of the input shaft 16. The parking brake 32 is constantly pressed by a spring (not shown) against a plate 32a constituting the parking brake 32. Thereby, the rotation of the input shaft 16 is blocked. When releasing the parking brake 32, hydraulic oil is supplied to the parking brake 32. As a result, the spring (not shown) is compressed and deformed by the pressure of the hydraulic oil. As a result, the pressing of the plate 32a by the spring is released, and the input shaft 16 is also released.

[0046] On the outer peripheral wall 20a of the bearing housing 20, a deceleration side oil passage 33 is formed for communicating the connection port 14 of the transmission side housing 10 with the inside of the recess 28. Through this deceleration side oil passage 33, the connection port 14 of the transmission side housing 10, the transmission side oil passage 15, and the hydraulic oil injection port 23, hydraulic oil from the outside is supplied into the recess 28. Thereby, the parking brake 32 is actuated. On the side of the bearing housing 20 opposite to the transmission mechanism 3, a plurality of second struts 49 project and are integrally formed. This second strut 49 forms part of the gear mechanisms 18A and 18B.

[0047] The gear mechanisms 18A and 18B are arranged coaxially with the rotation axis Jn on the side of the bearing housing 20 opposite to the transmission mechanism 3. The gear mechanisms 18A and 18B are arranged in the order of the first-stage gear mechanism 18A and the second-stage gear mechanism 18B from the side opposite to the transmission mechanism 3 toward the bearing housing 20 side.

[0048] The first-stage gear mechanism 18A is a so-called planetary gear mechanism. The first-stage gear mechanism 18A includes a first sun gear 35 connected to the other end 16b of the input shaft 16 via a coupling 34, a first planetary gear 36 meshed with the first sun gear 35, an internal gear 37 meshed with the first planetary gear 36, and a first planetary carrier 38 that supports the first planetary gear 36. The first sun gear 35 rotates integrally with the input shaft 16. A plurality (for example, three) of the first planetary gears 36 are provided. Each first planetary gear 36 is arranged at equal intervals around the first sun gear 35.

[0049] The internal gear 37 is formed in a cylindrical shape so as to surround the periphery of each of the gear mechanisms 18A and 18B and the bearing housing 20. One end 37a of the internal gear 37 on the transmission mechanism 3 side approaches the base portion 19 of the reduction side housing 17. A mechanical seal (floating seal) 40 is provided between the base portion 19 and one end 37a of the internal gear 37. This mechanical seal 40 can prevent the grease (lubricating oil) filled in the internal gear 37 from leaking to the outside from between one end 37a of the internal gear 37 and the base portion 19.

[0050] On the other end 37b of the internal gear 37, which is opposite to the transmission mechanism 3, an end plate 41 for closing the opening 37c of the internal gear 37 is provided. On the outer peripheral surface of the internal gear 37, a plurality of second fixed seats 42 are integrally formed so as to project radially outward near the transmission side housing 10. The second fixed seat 42 is for transmitting the driving force of the crawler drive unit 1 to the traveling unit 102 (details will be described later).

[0051] The position corresponding to the bearing housing 20 of the internal gear 37 is rotatably supported with respect to the bearing housing 20 via two bearings 39a and 39b. Internal teeth 37d are formed at positions corresponding to the respective gear mechanisms 18A and 18B of the internal gear 37. The first planetary gear 36 is meshed with the internal teeth 37d.

[0052] The first planetary carrier 38 that supports the first planetary gear 36 is disposed on the bearing housing 20 side of the first planetary gear 36. On one surface 38a of the first planetary carrier 38 on the first planetary gear 36 side, a first support column 43 for rotatably supporting the first planetary gear 36 projects. Further, on the other surface 38b of the first planetary carrier 38 on the bearing housing 20 side, a second sun gear 45 that constitutes the second-stage gear mechanism 18B is integrally provided.

[0053] The second-stage gear mechanism 18B includes, in addition to the second sun gear 45, a carrier gear 46 meshed with the second sun gear 45, and an internal gear 37 meshed with the carrier gear 46. The internal gear 37 is shared with the first-stage gear mechanism 18A. The second sun gear 45 is formed in a cylindrical shape. A coupling 34 is inserted into the second sun gear 45 so as to be rotatable with respect to the second sun gear 45. A plurality of (for example, three) carrier gears 46 are provided. Each carrier gear 46 is arranged at equal intervals around the second sun gear 45. These carrier gears 46 are rotatably supported by a second support column 49 integrally formed with the bearing housing 20.

[0054] Under such a configuration, the crawler drive unit 1 is arranged such that the internal gear 37 of the speed reduction mechanism 4 is accommodated inside the drive wheel 108 in the radial direction. The electric motor 2 is positioned inside the speed reduction mechanism 4 in the vehicle width direction. And the second fixed seat 42 of the internal gear 37 is fixed to the drive wheel 108. The internal gear 37 is rotated integrally with the drive wheel 108. On the other hand, the first fixed seat 27 of the speed reduction side housing 17 is fixed to the track frame 107.

[0055] Here, as shown in detail in FIG. 1, when the crawler drive unit 1 is attached to the traveling unit 102, the entire speed reduction mechanism 4 and substantially the entire transmission mechanism 3 are accommodated within the vehicle width of the traveling unit 102. More specifically, in FIG. 1, only the closing plate 22 of the transmission mechanism 3 protrudes inward in the vehicle width direction from the traveling unit 102.

[0056] Also, the rotation axis Jm of the motor shaft 7 is located directly above the rotation axis Jn (the rotation axis Jh of the second spur gear 12) of the input shaft 16. The entire electric motor 2 is positioned above the bottom surface 104a of the lower frame 104. Here, the entire electric motor 2 refers to the connector 50, the motor case 5, and the support case 8 that form the outer shell of the electric motor 2. Above means in the upward direction of the gravitational force, and the position becomes farther from the road surface as it goes upward. In FIG. 1, in terms of the front-rear direction, the position of the lower side of the motor case 5 coincides with the position of the bottom surface 104a in terms of the detailed positional relationship between the electric motor 2 and the lower frame 104.

[0057] <Operation of the Crawler Drive Unit> Next, the operation of the crawler drive unit 1 will be described. As shown in FIGS. 2 and 3, by driving the electric motor 2, the motor shaft 7 of the rotor 6 is rotated. When the motor shaft 7 is rotated, the rotation of this motor shaft 7 is transmitted to the input shaft 16 of the speed reduction mechanism 4 via the first spur gear 11 and the second spur gear 12 of the transmission mechanism 3. At this time, the rotation of the motor shaft 7 is decelerated and transmitted to the input shaft 16 by the two spur gears 11 and 12.

[0058] When the motor shaft 7 rotates, the first sun gear 35 rotates integrally with the motor shaft 7. Then, the first planetary gear 36 meshed with the first sun gear 35 and the internal gear 37 revolves around the first sun gear 35 while rotating about the first support column 43. And the first planetary carrier 38 supporting the first planetary gear 36 rotates about the rotation axis Jn of the input shaft 16. Further, the second sun gear 45 rotates integrally with the first planetary carrier 38. The second sun gear 45 is formed in a cylindrical shape, and since the coupling 34 is inserted inside in the radial direction, the rotation of the second sun gear 45 and the rotation of the input shaft 16 do not interfere with each other.

[0059] When the second sun gear 45 rotates, the carrier gear 46 meshed with the second sun gear 45 and the internal gear 37 rotates about the second support column 49. And due to the rotation of the carrier gear 46, the internal gear 37 rotates. Then, the drive wheel 108 rotates integrally with the internal gear 37. That is, the internal gear 37 decelerates the rotation of the motor shaft 7 and outputs it to the drive wheel 108. When the drive wheel 108 rotates, the crawler 109 is actuated and the construction machine 100 travels. In this way, the speed reduction mechanism 4 transmits the driving force to the crawler 109 via the drive wheel 108. The electric motor 2 applies the driving force to the speed reduction mechanism 4 via the transmission mechanism 3.

[0060] Here, in the crawler drive unit 1, the rotation axis Jm of the motor shaft 7 is located directly above the rotation axis Jn (the rotation axis Jh of the second spur gear 12) of the input shaft 16. And the whole electric motor 2 is located upward from the bottom surface 104a of the lower frame 104. In this way, the above-described crawler drive unit 1 can position the electric motor 2 above the speed reduction mechanism 4. Therefore, even when the crawler drive unit 1 including the electric motor 2 and the speed reduction mechanism 4 is provided in the traveling unit 102 and the electric motor 2 protrudes in the vehicle width direction from the traveling unit 102, the position of the electric motor 2 can be separated from the road surface as much as possible. Thus, the possibility of the electric motor 2 coming into contact with earth and sand, rock, etc. during the traveling of the construction machine 100 can be reduced. Also, a construction machine 100 with high traveling performance can be achieved.

[0061] In particular, by positioning the entire electric motor 2 upward from the bottom surface 104a of the lower frame 104, the possibility of the electric motor 2 coming into contact with earth and sand, rock, etc. during the traveling of the construction machine 100 can be surely reduced. Also, as the position of the electric motor 2 is raised as much as possible, it becomes possible to secure a working space below the electric motor 2. Therefore, the maintainability of the crawler drive unit 1 can be improved.

[0062] The electric motor 2 (motor shaft 7) and the speed reduction mechanism 4 (input shaft 16) connected via the transmission mechanism 3 have their respective rotation axes Jm, Jn parallel. Therefore, the transmission efficiency of the driving force from the electric motor 2 to the speed reduction mechanism 4 can be improved as compared with the case where the respective rotation axes Jm, Jn intersect. More specifically, the transmission mechanism 3 can be configured by meshing two spur gears 11, 12. By using the spur gears 11, 12, the rotation of the motor shaft 7 can be efficiently transmitted to the input shaft 16.

[0063] Moreover, the number of teeth of the second spur gear 12 is larger than the number of teeth of the first spur gear 11. Therefore, the rotation of the second spur gear 12 is decelerated with respect to the rotation of the first spur gear 11. That is, in addition to the speed reduction mechanism 4, the transmission mechanism 3 can also decelerate the rotation of the motor shaft 7. Thus, while miniaturizing the crawler drive unit 1, a high reduction ratio can be obtained, and a high-output crawler drive unit 1 can be provided.

[0064] In addition, when the crawler drive unit 1 is attached to the traveling unit 102, the entire speed reduction mechanism 4 and substantially the entire transmission mechanism 3 are housed within the width of the traveling unit 102 in the vehicle width direction. For this reason, since the periphery of the speed reduction mechanism 4 can be covered by the traveling unit 102 (drive wheel 108), it is possible to prevent the speed reduction mechanism 4 from coming into contact with earth and sand, rock, etc. Therefore, the possibility of the speed reduction mechanism 4 being damaged can be reduced.

[0065] In the above-described first embodiment, the case where the entire electric motor 2 is positioned upward from the bottom surface 104a of the lower frame 104 has been described. However, the present invention is not limited to this, and the entire electric motor 2 may be positioned above the rotation axis Jn of the input shaft 16. Even in such a configuration, compared with the case where the rotation axis Jm of the motor shaft 7 and the rotation axis Jn of the input shaft 16 are located on the same straight line, the position of the electric motor 2 can be positioned higher than that of the speed reduction mechanism 4. For this reason, the same effects as those of the first embodiment described above can be obtained.

[0066] [Second Embodiment] Next, with reference to FIG. 1 and based on FIGS. 4 and 5, a second embodiment of the present invention will be described. FIG. 4 is a plan view of the traveling unit 102, the lower frame 104, and the crawler drive unit 201 in the second embodiment as viewed from the front-rear direction. FIG. 5 is a schematic view of a part of the traveling unit 102 and the crawler drive unit 201 in the second embodiment as viewed from the vehicle width direction. FIG. 5 corresponds to the view taken along arrow A in FIG. 4. In the following description, the same reference numerals are given to the same aspects as those in the first embodiment described above, and the description thereof will be omitted (the same applies to the third embodiment below).

[0067] In the second embodiment, the construction machine 100 includes a vehicle body main body 101, a traveling unit 102 for traveling the vehicle body main body 101, and a crawler drive unit 201 provided on the traveling unit 102 for driving the traveling unit 102 (see also FIG. 1), which is the same as that in the first embodiment described above (the same applies to the third embodiment below). The difference between the first embodiment and the second embodiment lies in the mounting orientation of the electric motor 2 in the crawler drive unit 1 of the first embodiment and the mounting orientation of the electric motor 2 in the crawler drive unit 201 of the second embodiment.

[0068] Specifically, as shown in FIGS. 4 and 5, the electric motor 2 of the crawler drive unit 201 provided in each traveling unit 102 is displaced in the front-rear direction with respect to the speed reduction mechanism 4. For this reason, the two electric motors 2 are arranged side by side in the front-rear direction. Further, the entire electric motor 2 is accommodated on the projection plane of the traveling unit 102. Furthermore, the rotation axis Jm of the motor shaft 7 of the crawler drive unit 201 and the rotation axis Jn of the input shaft 16 are arranged on the same horizontal line. In other words, the electric motor 2 and the speed reduction mechanism 4 are arranged at the same height.

[0069] By configuring in this way, for example, as shown in FIG. 4, even when the distance between the left and right traveling units 102 is short, it is possible to prevent the crawler drive units 201 provided in each traveling unit 102 from interfering with each other. In addition, it is not necessary to prepare the crawler drive unit 201 individually according to the difference in the distance between the left and right traveling units 102, and the versatility of the crawler drive unit 201 can be enhanced.

[0070] [Modification of the Second Embodiment] FIG. 6 is a schematic view of a part of the traveling unit 102 and the crawler drive unit 201 in a modification of the second embodiment as viewed from the vehicle width direction. FIG. 6 corresponds to FIG. 5 described above. In the above-described second embodiment, the case where the rotation axis Jm of the motor shaft 7 of the crawler drive unit 201 and the rotation axis Jn of the input shaft 16 are arranged on the same horizontal line has been described. However, the present invention is not limited to this, and as shown in FIG. 6, the rotation axis Jm of the motor shaft 7 may be positioned above the rotation axis Jn of the input shaft 16. By configuring in this way, in addition to the same operational effects as those of the above-described second embodiment, the possibility that the electric motor 2 comes into contact with earth and sand, rock, etc. during the traveling of the construction machine 100 can be reduced.

[0071] [Third Embodiment] Next, based on FIG. 7, the third embodiment of the present invention will be described. FIG. 7 is a schematic view of a part of the traveling unit 102 and the crawler drive unit 301 in the third embodiment as viewed from the vehicle width direction. FIG. 7 corresponds to FIG. 5 described above. As shown in FIG. 7, the difference between the second embodiment and the third embodiment lies in that the transmission mechanism 3 of the second embodiment (first embodiment) is different from the transmission mechanism 303 of the third embodiment.

[0072] Specifically, the transmission mechanism 303 includes a third spur gear 60 between the first spur gear 11 and the second spur gear 12. The number of teeth of the third spur gear 60 may be different from the number of teeth of the first spur gear 11 and the number of teeth of the second spur gear 12. Also, the number of teeth of the third spur gear 60 may be the same as the number of teeth of the first spur gear 11. In this third embodiment, the number of teeth of the third spur gear 60 is the same as the number of teeth of the first spur gear 11. Further, the rotation axis Jm of the motor shaft 7 of the crawler drive unit 301 and the rotation axis Jn of the input shaft 16 are arranged on the same horizontal line. In other words, the electric motor 2 and the speed reduction mechanism 4 are arranged at the same height.

[0073] Therefore, according to the third embodiment described above, the same effects as those of the second embodiment described above are achieved. In addition to this, since the transmission mechanism 303 is composed of three spur gears 11, 12, and 60, the position of the rotation axis Jm of the motor shaft 7 and the position of the rotation axis Jn of the input shaft 16 can be greatly shifted. Accordingly, the degree of freedom in the layout of the crawler drive unit 301 can be increased.

[0074] Also, by making the number of teeth of the third spur gear 60 different from the number of teeth of the first spur gear 11 and the number of teeth of the second spur gear 12, the reduction ratio can be increased by the transmission mechanism 303. For this reason, while miniaturizing the crawler drive unit 301, a high reduction ratio can be obtained, and a high-output crawler drive unit 301 can be provided.

[0075] In the above-described third embodiment, the case where the transmission mechanism 303 is constituted by the three spur gears 11, 12, and 60 has been described. However, the present invention is not limited to this, and the transmission mechanism 303 may be constituted by four or more spur gears.

[0076] [Modification Example of the Third Embodiment] FIG. 8 is a schematic view of a part of the traveling unit 102 and the crawler drive unit 301 in a modification example of the third embodiment as viewed in the vehicle width direction. FIG. 8 corresponds to FIG. 7 described above. In the above-described third embodiment, the case where the rotation axis Jm of the motor shaft 7 of the crawler drive unit 301 and the rotation axis Jn of the input shaft 16 are arranged on the same horizontal line has been described. However, the present invention is not limited to this, and as shown in FIG. 8, the rotation axis Jm of the motor shaft 7 may be positioned above the rotation axis Jn of the input shaft 16. By configuring in this way, in addition to the same operational effects as those of the above-described third embodiment, the possibility that the electric motor 2 comes into contact with earth and sand, rock, etc. during the traveling of the construction machine 100 can be reduced.

[0077] Note that the configuration of the transmission mechanism 303 in the above-described third embodiment may be applied to the transmission mechanism 3 in the above-described first embodiment. By configuring in this way, the position of the electric motor 2 can be further positioned above with respect to the speed reduction mechanism 4. Therefore, the possibility that the electric motor 2 comes into contact with earth and sand, rock, etc. during the traveling of the construction machine 100 can be further reduced. Further, the construction machine 100 with higher traveling performance can be obtained.

[0078] The present invention is not limited to the above-described embodiments, and includes those obtained by making various modifications to the above-described embodiments without departing from the gist of the present invention. For example, in the above-described embodiments, the crawler drive units 1, 201, and 301 for driving the traveling unit 102 mounted on the construction machine 100 have been described. However, the present invention is not limited to this, and the above-described crawler drive units 1, 201, and 301 can be applied to various devices on which the traveling unit 102 is mounted.

[0079] In the above-described embodiment, the traveling unit 102 has been described for the case where it includes a truck frame 107, an idler, a drive wheel (sprocket) 108, a tumbler wheel, and a crawler 109 wound around these idler, drive wheel 108, and tumbler wheel. However, it is not limited to this, and the traveling unit 102 may have a configuration in which the crawler 109 is operated by rotating the drive wheel 108, and thereby the construction machine 100 travels.

[0080] In the above-described embodiment, the case where the transmission mechanisms 3 and 303 are constituted by a plurality of spur gears 11, 12, and 60 has been described. However, it is not limited to this, and the transmission mechanisms 3 and 303 may have a configuration capable of transmitting the rotation of the motor shaft 7 of the electric motor 2 to the input shaft 16 of the speed reduction mechanism 4. For example, the transmission mechanisms 3 and 303 may be constituted by a pulley and a timing belt. For example, the transmission mechanisms 3 and 303 may be constituted by a sprocket and a chain.

[0081] Also, for example, a universal joint may be adopted as the transmission mechanism. In this case, it is not necessarily required that the rotation axis Jm of the motor shaft 7 and the rotation axis Jn of the input shaft 16 are parallel. When the rotation axis Jm of the motor shaft 7 and the rotation axis Jn of the input shaft 16 intersect, it is sufficient that the motor shaft 7 is positioned above the rotation axis Jn of the input shaft 16. By configuring in this way, the same effects as those of the above-described embodiment can be obtained.

[0082] Furthermore, in the above-described embodiment, the case where the rotation of the motor shaft 7 is also decelerated by the transmission mechanisms 3 and 303 has been described. However, it is not limited to this, and the transmission mechanisms 3 and 303 may have a configuration capable of transmitting the rotation of the motor shaft 7 to the speed reduction mechanism 4. For example, the transmission mechanisms 3 and 303 may be configured to transmit the rotation of the motor shaft 7 at a constant speed or an increased speed to the speed reduction mechanism 4.

[0083] In the above-described embodiment, the case where the input portion in the claims is the input shaft 16 has been described. However, it is not limited to this, and the input portion only needs to have the function of inputting the rotation of the electric motor 2 to the speed reduction mechanism 4. For example, although the input shaft 16 is a solid shaft, it may be a hollow shaft instead of the solid shaft.

[0084] In the above-described embodiment, the case where the speed reduction mechanism 4 includes the two-stage gear mechanisms 18A and 18B has been described. The first-stage gear mechanism 18A is a so-called planetary gear mechanism, and the case where it includes the first sun gear 35, the first planetary gear 36, the internal gear 37, and the first planetary carrier 38 has been described. The second-stage gear mechanism 18B is the case where it includes the second sun gear 45, the carrier gear 46, and the internal gear 37. However, it is not limited to this, and the speed reduction mechanism 4 only needs to be configured to reduce the rotation of the motor shaft 7 of the electric motor 2 and output it. For example, a plurality of spur gears may be meshed so that the rotation axis of the input portion and the rotation axis of the output portion (output side) are offset.

[0085] In the above-described embodiment, the case where the speed reduction mechanism 4 transmits the rotation of the motor shaft 7 of the electric motor 2 transmitted through the transmission mechanisms 3 and 303 from the internal gear 37 to the drive wheel 108 has been described. However, it is not limited to this, and it is only necessary that the rotation of the motor shaft 7 can be transmitted to the drive wheel 108 by the speed reduction mechanism 4. That is, for example, when the speed reduction mechanism is composed of a plurality of spur gears, it is only necessary that the rotation of the motor shaft 7 can be transmitted from the final-stage spur gear to the drive wheel 108.

[0086] In the above-described embodiment, the case where the electric motor 2 protrudes in the vehicle width direction from the traveling unit 102 has been described. However, the present invention is not limited to this. For example, even when the crawler drive units 1, 201, 301 can be housed in the traveling unit 102 and the electric motor 2 does not protrude in the vehicle width direction from the traveling unit 102, the configuration of the above-described crawler drive units 1, 201, 301 can be adopted. However, when the electric motor 2 protrudes in the vehicle width direction from the traveling unit 102, the configuration of the above-described crawler drive units 1, 201, 301 can be preferably used.

[0087] In the above-described embodiment, the case where the internal gear 37 of the speed reduction mechanism 4 is provided integrally with the drive wheel 108 in the crawler drive units 1, 201, 301 has been described. And the case where the internal gear 37 is rotated integrally with the drive wheel 108 has been described. However, the present invention is not limited to this. It is only necessary that the crawler 109 is operated by the output of the speed reduction mechanism 4. For example, the internal gear 37 may be formed to function as the drive wheel 108 so that the crawler 109 is wound around the internal gear 37 itself.

[0088] Among the embodiments disclosed in this specification, those constituted by a plurality of objects may be integrated into the plurality of objects, and conversely, those constituted by one object may be divided into a plurality of objects. Regardless of whether they are integrated or not, they may be configured so as to achieve the object of the invention.

Explanation of Reference Numerals

[0089] 1, 201, 301... Crawler drive unit 2... Electric motor 3, 303... Transmission mechanism 4... Speed reduction mechanism 7... Motor shaft 11... First spur gear (gear) 12... Second spur gear (gear) 16... Input shaft (input portion) 37... Internal gear 60... Third spur gear (gear) 100... Construction machine 101…Vehicle body main body 102…Running gear 104…Lower frame (vehicle body main body) 104a…Bottom surface 109…Crawler Jm…Axis of rotation of motor shaft Jn…Axis of rotation of input shaft

Claims

1. A speed reduction mechanism provided in a traveling unit that drives a vehicle body main body and transmits a driving force to a crawler provided in the traveling unit; A transmission mechanism that transmits the driving force to the speed reduction mechanism; An electric motor that applies a rotational force to the transmission mechanism, and comprises: The electric motor includes: A motor case; A motor shaft protruding from the motor case; A support case that protrudes in the same direction as the direction in which the motor shaft protrudes from the motor case and is formed in a cylindrical shape so as to cover the periphery of the motor shaft, and rotatably supports the motor shaft; Comprises; The motor shaft is located above the rotation axis of the input portion where the driving force from the transmission mechanism of the speed reduction mechanism is input; The end of the support case on the side opposite to the motor case is fixed to the transmission mechanism Crawler drive unit.

2. The crawler drive unit according to claim 1, wherein the rotation axis of the motor shaft and the rotation axis of the input portion are parallel.

3. The electric motor is provided so as to protrude in the vehicle width direction of the vehicle body main body from the speed reduction mechanism The crawler drive unit according to claim 1 or claim 2.

4. The transmission mechanism is formed by meshing a plurality of gears The crawler drive unit according to any one of claims 1 to 3.

5. The transmission mechanism according to any one of claims 1 to 4, wherein the rotation of the motor shaft is decelerated and transmitted to the input portion.

6. The crawler drive unit according to any one of claims 1 to 5, wherein the entire electric motor is located above the rotation axis of the input portion.

7. The crawler drive unit according to any one of claims 1 to 6, wherein the entire electric motor is located above the bottom surface of the vehicle body main body.

8. At least a part of the speed reduction mechanism is housed within the width of the vehicle body main body in the vehicle width direction of the crawler The crawler drive unit according to any one of claims 1 to 7.

9. The speed reduction mechanism is provided in each of the two traveling units on the left and right of the vehicle body main body, The transmission mechanism is provided in each of the speed reduction mechanisms, The electric motors are provided so as to protrude inward in the vehicle width direction of the vehicle body main body from the speed reduction mechanisms, The two electric motors are arranged side by side in the front-rear direction of the vehicle body main body. The crawler drive unit according to any one of claims 1 to 8.

10. The vehicle body main body, The traveling unit that causes the vehicle body main body to travel, The crawler drive unit according to any one of claims 1 to 9 provided in the traveling unit, Comprising: The electric motor is provided so as to protrude in the vehicle width direction of the vehicle body main body from the speed reduction mechanism, and applies a rotational force to the speed reduction mechanism. The transmission mechanism decelerates the rotation of the motor shaft of the electric motor and transmits it to the speed reduction mechanism. The entire electric motor is located above the bottom surface of the vehicle body main body including the bottom surface of the vehicle body main body. Construction machinery.

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