Motor drive assembly for industrial machinery and industrial machinery

Abstract

To miniaturize motor drive assemblies for industrial machinery while achieving a large reduction ratio. [Solution] The motor drive assembly for the work machine comprises a motor, a central shaft, a planetary gear mechanism, a brake, a fixed case, a housing, and a sprocket. The central shaft is fixed to the motor. The planetary gear mechanism includes a sun gear, a first planetary gear, a first ring gear, a second planetary gear, a second ring gear, and a carrier. The sun gear is fixed to the central shaft. The second planetary gear is integrated with the first planetary gear. The carrier supports the first and second planetary gears. The brake is connected to the carrier. The brake is positioned axially between the motor and the planetary gear mechanism. The second ring gear is fixed to the fixed case. The housing houses the planetary gear mechanism. The first ring gear is fixed to the housing.

Description

Technical Field

[0001] The present disclosure relates to a motor drive assembly for a work machine and a work machine.

Background Art

[0002] A motor drive assembly for a work machine includes a motor assembly and a final drive assembly. The final drive assembly is connected to the motor assembly. For example, the motor drive assembly of Patent Document 1 includes a brake and a planetary gear mechanism. The brake is connected to the motor assembly. The planetary gear mechanism is connected to a sprocket. Rotation from the motor assembly is transmitted to the planetary gear mechanism via the brake, decelerated, and then transmitted to the sprocket.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In a motor drive assembly, it is desired to achieve miniaturization and obtain a large reduction ratio. An object of the present disclosure is to miniaturize a motor drive assembly for a work machine and obtain a large reduction ratio.

Means for Solving the Problems

[0005] A motor drive assembly for a work machine according to one aspect of the present disclosure comprises a motor, a central shaft, a planetary gear mechanism, a brake, a fixed case, a housing, and a sprocket. The central shaft is fixed to the motor. The planetary gear mechanism is located outside the motor in the axial direction of the motor drive assembly. The planetary gear mechanism includes a sun gear, a first planetary gear, a first ring gear, a second planetary gear, a second ring gear, and a carrier. The sun gear is fixed to the central shaft. The first planetary gear meshes with the sun gear. The first ring gear meshes with the first planetary gear. The second planetary gear is integrated with the first planetary gear. The second ring gear meshes with the second planetary gear. The carrier supports the first and second planetary gears. The brake is connected to the carrier. The brake is located between the motor and the planetary gear mechanism in the axial direction. The fixed case houses the brake. The second ring gear is fixed to the fixed case. The housing is rotatably supported by the fixed case and houses the planetary gear mechanism. The first ring gear is fixed to the housing.

[0006] Other aspects of the present disclosure of work machines include a body and a running gear. The running gear supports the body. The running gear includes the motor drive assembly described above. [Effects of the Invention]

[0007] According to this disclosure, the motor drive assembly for industrial machinery can be miniaturized while achieving a large reduction ratio. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the work machine according to the embodiment. [Figure 2] This is a cross-sectional view of a motor drive assembly. [Figure 3] This is a skeleton diagram of a motor drive assembly. [Modes for carrying out the invention]

[0009] The following description of the working machine according to the embodiment will be made with reference to the drawings. Figure 1 is a perspective view of the working machine 1 according to the embodiment. The working machine 1 according to this embodiment is a bulldozer. As shown in Figure 1, the working machine 1 comprises a body 2, a working machine 3, and left and right traveling devices 4 and 5. The body 2 includes a driver's cab 6 and a power room 7. The power room 7 is located in front of the driver's cab 6. The working machine 3 is operably supported relative to the body 2. The working machine 3 includes a blade 8.

[0010] The running gears 4 and 5 support the vehicle body 2. The left running gear 4 includes a track 11, a motor drive assembly 12, and a track frame 13. The track frame 13 supports the track 11 via several road wheels (not shown) and idlers. The track 11 is wrapped around the motor drive assembly 12. The motor drive assembly 12 is mounted on the track frame 13. The axis Ax1 of the motor drive assembly 12 extends in the left-right direction of the work machine 1. In the following description, the direction parallel to axis Ax1 is defined as the axial direction. The configuration of the right running gear 5 is the same as that of the left running gear 4, so its description is omitted.

[0011] Figure 2 is a cross-sectional view of the motor drive assembly 12. Figure 3 is a skeleton diagram of the motor drive assembly 12. The motor drive assembly 12 includes a motor assembly 21 and a final drive assembly 22. The motor assembly 21 is connected to the final drive assembly 22. In this embodiment, the motor assembly 21 is an electric motor.

[0012] The motor assembly 21 includes a motor 40 and a motor case 41. The motor 40 includes a stator 42, a rotor 43, and a motor shaft 44. The stator 42 and rotor 43 are located inside the motor case 41. The stator 42 is fixed to the inner surface of the motor case 41. The motor shaft 44 is fixed to the rotor 43. The motor shaft 44 and rotor 43 are rotatably supported in the motor case 41. The motor shaft 44 extends in the axial direction. The motor shaft 44 protrudes outward from the motor case 41 in the axial direction.

[0013] The final drive assembly 22 is located outside the motor assembly 21 in the axial direction. The final drive assembly 22 includes a fixed case 23, a final drive housing 24, and a sprocket 25. The final drive assembly 22 is located coaxially with the motor assembly 21. The fixed case 23 is located coaxially with the motor shaft 44. As will be described in detail later, the final drive housing 24 is rotatably supported by the fixed case 23. The final drive assembly 22 is fixed to the track frame 13 via the fixed case 23. The motor case 41 is mounted on the fixed case 23. The motor assembly 21 is fixed to the track frame 13 via the fixed case 23.

[0014] The fixed case 23 includes a fixed case housing 73 and a partition wall 74. The fixed case 23 supports the final drive housing 24 via bearings 77 and 78. The partition wall 74 is a separate component from the fixed case housing 73. The partition wall 74 separates the inside of the motor case 41 from the inside of the fixed case housing 73.

[0015] The final drive housing 24 is positioned coaxially with the fixed case 23. The final drive housing 24 is rotatably supported by the fixed case 23. The sprocket 25 is fixed to the outer circumference of the final drive housing 24. The track 11 is wound around the sprocket 25.

[0016] The final drive assembly 22 includes a central shaft 45, a brake 52, and a planetary gear mechanism 100. The central shaft 45 is coaxially positioned with the fixed case 23. The central shaft 45 extends in the axial direction. The central shaft 45 is rotatably supported by the fixed case 23 via bearings 47. The central shaft 45 is rotatably supported by the bulkhead 74 via bearings 47. The central shaft 45 is coaxially positioned with the motor shaft 44. The central shaft 45 is fixed to the motor shaft 44. The central shaft 45 rotates integrally with the motor shaft 44.

[0017] The brake 52 is located outside the motor assembly 21 in the axial direction. The brake 52 is located between the motor assembly 21 and the planetary gear mechanism 100 in the axial direction. The brake 52 is located inside the fixed case housing 73 of the fixed case 23. The brake 52 is connected to the planetary gear mechanism 100. The brake 52 brakes the rotation of the planetary gear mechanism 100, thereby braking the sprocket 25. The brake 52 includes a rotating shaft 58, a brake hub 59, a plurality of brake discs 60, a piston 62, and a biasing member 63.

[0018] The rotating shaft 58 is positioned coaxially with the fixed case 23. The rotating shaft 58 extends axially. The rotating shaft 58 is rotatably supported by the fixed case 23 via bearings 48, 49. The rotating shaft 58 includes a hole 50 that extends axially. The central shaft 45 is positioned through the hole 50 of the rotating shaft 58. The central shaft 45 extends axially through the rotating shaft 58. The rotating shaft 58 is rotatable relative to the central shaft 45.

[0019] The brake hub 59 is fixed to the rotating shaft 58. The brake hub 59 rotates integrally with the rotating shaft 58. Some of the brake discs 60 are connected to the brake hub 59 in a way that prevents rotation and allows axial movement relative to the brake hub 59. The remaining brake discs 60 are supported by a fixed case 23 so as to be axially movable.

[0020] The piston 62 is arranged facing the brake disk 60 in the axial direction. The piston 62 is supported by the fixed case 23 so as to be movable in the axial direction. The biasing member 63 is, for example, a coil spring. Alternatively, the biasing member 63 may be another spring such as a leaf spring. The biasing member 63 biases the piston 62 in the direction of pressing the brake disk 60. The piston 62 presses the brake disk 60 by the biasing force of the biasing member 63. Thereby, the brake 52 brakes the planetary gear mechanism 100. The piston 62 is driven, for example, by hydraulic pressure, and moves in a direction away from the brake disk 60 against the biasing force of the biasing member 63. Thereby, the brake 52 releases the planetary gear mechanism 100. That is, the brake 52 is a negative-type brake whose braking state is released by the supply of hydraulic oil.

[0021] The planetary gear mechanism 100 is arranged in the final drive housing 24. The planetary gear mechanism 100 is connected to the final drive housing 24. The planetary gear mechanism 100 decelerates the rotation of the central shaft 45 and transmits it to the final drive housing 24. The planetary gear mechanism 100 is arranged outside the brake 52 in the axial direction. The planetary gear mechanism 100 includes a sun gear 101, a first planetary gear 102, a first ring gear 103, a second planetary gear 104, a second ring gear 105, and a carrier 106.

[0022] The sun gear 101 is fixed to the central shaft 45. The sun gear 101 rotates integrally with the central shaft 45. The first planetary gear 102 meshes with the sun gear 101. The first planetary gear 102 is revolvable around the sun gear 101. The first planetary gear 102 is supported by the carrier 106 so as to be rotatable. The first ring gear 103 meshes with the first planetary gear 102. The first ring gear 103 is fixed to the inner peripheral surface of the final drive housing 24. The first ring gear 103 rotates together with the final drive housing 24.

[0023] The second planetary gear 104 is integrated with the first planetary gear 102. The number of teeth of the second planetary gear 104 is different from the number of teeth of the first planetary gear 102. For example, the number of teeth of the second planetary gear 104 is less than the number of teeth of the first planetary gear 102. Alternatively, the number of teeth of the second planetary gear 104 may be more than the number of teeth of the first planetary gear 102. The second planetary gear 104 revolves around the sun gear 101 integrally with the first planetary gear 102. The second planetary gear 104 is rotatably supported by the carrier 106. The second planetary gear 104 rotates integrally with the first planetary gear 102. The second ring gear 105 meshes with the second planetary gear 104. The second ring gear 105 is fixed to the fixed case 23. The carrier 106 is fixed to the rotation shaft 58 of the brake 52. The rotation shaft 58 rotates together with the carrier 106.

[0024] In the motor drive assembly 12 according to the present embodiment, the rotation of the motor 40 is transmitted to the final drive housing 24 via the central axis 45, the sun gear 101, the first planetary gear 102, and the first ring gear 103. Thereby, the sprocket 25 rotates together with the final drive housing 24.

[0025] Also, the second planetary gear 104 revolves around the sun gear 101 together with the first planetary gear 102. The carrier 106 rotates together with the revolution of the second planetary gear 104. The brake hub 59 rotates together with the rotation shaft 58 and the carrier 106. Therefore, when the rotation of the carrier 106 is braked by the brake 52, the sprocket 25 is braked.

[0026] In the motor drive assembly 12 according to the present embodiment described above, in the planetary gear mechanism 100, the first planetary gear and the second planetary gear are integrated. Therefore, the motor drive assembly for the work machine is miniaturized and a large reduction ratio can be obtained.

[0027] Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the invention.

[0028] The work machine 1 is not limited to a bulldozer, but may be other machines such as an excavator, wheel loader, grader, or dump truck. The configuration of the running gears 4 and 5 is not limited to that of the above embodiment and may be changed. For example, the running gears 4 and 5 may include tires instead of tracks. The structure or arrangement of the motor assembly 21 and the final drive assembly 22 is not limited to that of the above embodiment and may be changed. [Industrial applicability]

[0029] According to this disclosure, the motor drive assembly for industrial machinery can be miniaturized while achieving a large reduction ratio. [Explanation of symbols]

[0030] 1: Working machine, 2: Vehicle body, 4,5: Running gear, 20: Motor 24: Final drive housing, 25: Sprocket, 45: Center shaft, 52: Brake, 58: Rotating shaft, 101: Sun gear, 102: First planetary gear, 103: First ring gear, 104: Second planetary gear, 105: Second ring gear, 106: Carrier, 100: Planetary gear mechanism

Claims

1. A motor drive assembly for industrial machinery, Motor and, A planetary gear mechanism comprising a central shaft fixed to the motor, a sun gear fixed to the central shaft, a first planetary gear meshing with the sun gear, a first ring gear meshing with the first planetary gear, a second planetary gear integrated with the first planetary gear, a second ring gear meshing with the second planetary gear, and a carrier supporting the first and second planetary gears, wherein the planetary gear mechanism is positioned outside the motor in the axial direction of the motor drive assembly, A brake connected to the carrier and positioned between the motor and the planetary gear mechanism in the axial direction, A fixed case housing the brake and to which the second ring gear is fixed, A housing that is rotatably supported in the aforementioned fixed case, houses the planetary gear mechanism, and has the first ring gear fixed to it, A motor drive assembly equipped with [a specific feature / feature].

2. The brake includes a rotating shaft fixed to the carrier, The aforementioned central axis extends axially through the aforementioned rotation axis. The motor drive assembly according to claim 1.

3. The car body and, A running gear that supports the aforementioned vehicle body, Equipped with, The traveling device includes the motor drive assembly described in claim 1. A type of machinery used for industrial work.

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