Crawler drive unit and construction machine

Abstract

The present application provides a track drive unit and a construction machine. A track drive unit (1) of one aspect of the present application includes a reduction mechanism (4) provided in a traveling portion (102) that makes a vehicle body main body (101) travel, which transmits a driving force to a track provided to the traveling portion (102); a transmission mechanism (3) that transmits the driving force to the reduction mechanism (4); and an electric motor (2) that imparts a rotational force to the transmission mechanism (3). A motor shaft (7) of the electric motor (2) is positioned above a rotational axis (Jn) of an input shaft (16) of the reduction mechanism (4).

Description

Technical Field

[0001] This invention relates to a tracked drive unit and construction machinery. Background Technology

[0002] Construction machinery uses tracks as a running gear, enabling the main body of the machine to move on rough roads, replacing the wheels used in passenger cars. The tracks mesh with drive wheels (sprockets) that rotate around an axis of rotation.

[0003] Hydraulic drive units are commonly used as drive units to rotate the drive wheels. These units utilize hydraulic motors, which readily provide high torque. In addition to the hydraulic motor, a hydraulic drive unit includes a hydraulic pump for supplying working oil to the motor and an engine for driving the pump. Working oil sprayed from the hydraulic pump is supplied to the hydraulic motor via piping wound around the construction machinery.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2008-240342 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] However, in recent years, there has been a growing expectation to replace hydraulic drive units with electric drive units for the purpose of simplifying construction machinery. Electric drive units include batteries that replace the engine and electric motors powered by the battery's electricity. Electric drive units eliminate the need for hydraulic pumps and piping.

[0009] When comparing electric motors and hydraulic motors of the same size, the torque of an electric motor is often smaller than that of a hydraulic motor. Therefore, when using an electric drive unit, the size of the electric motor is increased, and a speed reduction mechanism is used simultaneously with the electric motor to reduce its rotation speed and output.

[0010] The reduction gear mechanism has multiple gears arranged freely within the housing. The reduction gear mechanism, located in the traveling section, has a structure where the housing serves as the output unit. Based on this structure, to prevent damage to the drive unit from sand, stones, etc., during the movement of the construction machinery, it is desirable to minimize the protrusion of the electric drive unit from the traveling section. Therefore, it is conceived to house the reduction gear mechanism coaxially with the drive wheel within the drive wheel, allowing the drive wheel and the housing (output unit) to rotate as a single unit.

[0011] However, simply replacing the hydraulic drive unit with an electric drive unit involves placing the electric motor and reduction gear within the space originally occupied by the hydraulic motor. Therefore, even if the reduction gear is controlled within the width of the travel section (within the width of the sprocket), the electric motor protrudes from the travel section in that direction. Consequently, during the movement of the construction machinery, the electric motor may come into contact with sand, stones, etc., increasing the possibility of damage. This is especially true when the reduction gear and electric motor are positioned at the same height, bringing the electric motor closer to the road surface. This correspondingly increases the likelihood of electric motor damage.

[0012] This invention provides a tracked drive unit and construction machinery that can reduce the possibility of electric motors coming into contact with sand, stones, etc.

[0013] Solution for solving the problem

[0014] One embodiment of the track drive unit of the present invention includes: a reduction mechanism disposed in a traveling section for moving a vehicle body, which transmits a driving force to a track disposed in the traveling section; a transmission mechanism that transmits the driving force to the reduction mechanism; and an electric motor that imparts a rotational force to the transmission mechanism. The reduction mechanism includes an input section from which the driving force is input from the transmission mechanism. The motor shaft of the electric motor is located above the rotation axis of the input section.

[0015] This configuration allows the electric motor to be positioned above the reduction gear. Therefore, even when the track drive unit, including the electric motor and reduction gear, is mounted on the track, and even if the electric motor protrudes from the track in the vehicle width direction, the electric motor can be positioned as far away from the road surface as possible. This reduces the likelihood of the electric motor coming into contact with sand, stones, or similar materials.

[0016] In the above structure, the rotation axis of the motor shaft may also be parallel to the rotation axis of the input section.

[0017] In the above structure, the electric motor may also be arranged such that it protrudes from the reduction mechanism in the width direction of the vehicle body.

[0018] In the above structure, the transmission mechanism may also include multiple meshing gears.

[0019] In the above structure, the transmission mechanism may also decelerate the rotation of the motor shaft and transmit it to the input section.

[0020] In the above structure, the entire electric motor may be located above the rotation axis of the input section.

[0021] In the above structure, the lower part of the electric motor may be aligned with the bottom surface of the vehicle body, or the entire electric motor may be positioned above the bottom surface of the vehicle body.

[0022] In the above structure, at least a portion of the deceleration mechanism may be housed within a region in the width direction of the vehicle body contained in the tracks.

[0023] Another embodiment of the track drive unit of the present invention includes: a reduction mechanism disposed in a traveling section for moving a vehicle body, which transmits driving force to a track disposed in the traveling section; a transmission mechanism that transmits the driving force to the reduction mechanism; and an electric motor disposed protruding from the reduction mechanism in the width direction of the vehicle body, which imparts rotational force to the reduction mechanism. The transmission mechanism reduces the rotation of the motor shaft of the electric motor and transmits it to the reduction mechanism. The lower part of the electric motor is aligned with the bottom surface of the vehicle body, or the entire electric motor is positioned above the bottom surface of the vehicle body.

[0024] This configuration allows the electric motor to be positioned above the reduction gear. Therefore, even when the track drive unit, including the electric motor and reduction gear, is mounted on the track, and even if the electric motor protrudes from the track in the vehicle width direction, the electric motor can be positioned as far away from the road surface as possible. This reduces the likelihood of the electric motor coming into contact with sand, stones, or similar materials.

[0025] In addition to using a reduction mechanism to slow down the rotation of the motor shaft, a transmission mechanism can also be used to slow down the rotation of the motor shaft. Therefore, it is possible to miniaturize the track drive unit while achieving a high reduction ratio, thus providing a high-output track drive unit.

[0026] Another embodiment of the track drive unit of the present invention includes: two reduction mechanisms disposed on two left and right travel sections for driving the vehicle body, transmitting driving force to the tracks disposed on each of the travel sections; a transmission mechanism for transmitting the driving force to the reduction mechanisms; and two electric motors disposed in a manner protruding from the reduction mechanisms toward the inside of the vehicle body in the width direction, imparting rotational force to the reduction mechanisms. The two electric motors are arranged in a longitudinal direction of the vehicle body.

[0027] With this configuration, even when the spacing between the left and right tracks is short, it is possible to prevent the track drive units installed on each track from interfering with each other.

[0028] There is no need to prepare track drive units separately according to the different spacing of the left and right tracks, which can improve the versatility of track drive units.

[0029] In the above structure, the two reduction mechanisms may each have an input section from which the driving force is input from the transmission mechanism. Alternatively, the motor shaft of the electric motor may be located above the rotation axis of the input section.

[0030] Another aspect of the construction machinery of the present invention comprises: a vehicle body; a traveling unit that drives the vehicle body; a reduction mechanism disposed on the traveling unit and transmitting driving force to a track disposed on the traveling unit; a transmission mechanism that transmits the driving force to the reduction mechanism; and an electric motor disposed such that it protrudes from the reduction mechanism in the width direction of the vehicle body and imparts rotational force to the reduction mechanism, the transmission mechanism reducing the rotation of the motor shaft of the electric motor and transmitting it to the reduction mechanism, wherein the lower part of the electric motor is aligned with the bottom surface of the vehicle body, or the entire electric motor is located above the bottom surface of the vehicle body.

[0031] This configuration allows the electric motor to be positioned above the reduction gear. Therefore, even when the track drive unit, including the electric motor and reduction gear, is mounted on the track, and even if the electric motor protrudes from the track in the width direction, the electric motor can be positioned as far away from the road surface as possible. This reduces the likelihood of the electric motor coming into contact with sand, rocks, etc., providing construction machinery with high mobility.

[0032] The effects of the invention

[0033] The aforementioned tracked drive unit and construction machinery can reduce the possibility of electric motors coming into contact with sand, rocks, etc. Attached Figure Description

[0034] Figure 1 This is a perspective view of the construction machinery in the first embodiment of the present invention.

[0035] Figure 2 This is a plan view of the track, lower frame, and track drive unit in the first embodiment of the present invention, viewed from the front and rear directions.

[0036] Figure 3 This is a cross-sectional view of the track drive unit in the first embodiment of the present invention.

[0037] Figure 4 This is a plan view of the track, lower frame, and track drive unit in the second embodiment of the present invention, viewed from the front and rear directions.

[0038] Figure 5 This is a partial schematic view of the track and track drive unit in the second embodiment of the present invention, viewed from the vehicle width direction.

[0039] Figure 6 This is a partial schematic view of the track and track drive unit in a modified example of the second embodiment of the present invention, viewed from the vehicle width direction.

[0040] Figure 7 This is a partial schematic view of the track and track drive unit in the third embodiment of the present invention, viewed from the vehicle width direction.

[0041] Figure 8 This is a partial schematic view of the track and track drive unit in a modified example of the third embodiment of the present invention, viewed from the vehicle width direction.

[0042] Explanation of reference numerals in the attached figures

[0043] 1, 201, 301, Track drive unit; 2, Electric motor; 3, 303, Transmission mechanism; 4, Reduction mechanism; 7, Motor shaft; 11, First spur gear; 12, Second spur gear; 16, Input shaft (input section); 37, Internal gear; 60, Third spur gear; 100, Construction machinery; 101, Body body; 102, Running gear; 104, Lower frame (body body); 104a, Bottom surface; 109, Track; Jm, Rotation axis of motor shaft; Jn, Rotation axis of input shaft. Detailed Implementation

[0044] Next, embodiments of the present invention will be described with reference to the accompanying drawings.

[0045] [First Implementation]

[0046] <Construction Machinery>

[0047] Figure 1 This is a 3D view of construction machinery 100.

[0048] like Figure 1 As shown, construction machinery 100 excavates, for example, sand. Construction machinery 100 performs civil engineering operations, such as transferring the excavated sand to other vehicles. Construction machinery 100 includes: a main body 101; a traveling unit 102 that moves the main body 101; and a track drive unit 1 disposed on the traveling unit 102 for driving the traveling unit 102. In the following description, the forward and backward direction of travel of construction machinery 100 is referred to as the forward and backward direction. The vehicle width direction of construction machinery 100, which is orthogonal to the forward and backward direction in the horizontal direction, is simply referred to as the vehicle width direction.

[0049] The vehicle body 101 includes: a rotating body 103; and a lower frame 104, which is disposed at the lower part of the rotating body 103 and supports the rotating body 103 for free rotation. The rotating body 103 includes: a cab 105 for an operator to sit in; and a boom 106, one end of which is connected to the rotating body 103 in a swing-free manner. Although in Figure 1 The details are omitted, but the stick is set at the other end of the boom 106 in a freely swinging manner. A bucket or the like is installed on the opposite end of the stick on the side opposite to the boom 106. Traveling parts 102 are provided on both sides of the lower frame 104 in the vehicle width direction.

[0050] The running gear 102 includes: a track frame 107 connected to a lower frame 104, which is longer in the longitudinal direction; an idler wheel (not shown) rotatably mounted at the front of the track frame 107; a drive wheel (sprocket) 108 rotatably mounted at the rear of the track frame 107; a plurality of rollers (not shown) rotatably mounted at the lower part of the track frame 107; and a track 109 wound over the idler wheel, drive wheel 108, and rollers. The track 109 is made of hard rubber, iron, or other metal. A track drive unit 1 is provided to drive the drive wheel 108 to rotate.

[0051] <track drive unit>

[0052] Figure 2 This is a plan view of the traveling section 102, the lower frame 104, and the track drive unit 1 from the front and rear directions. Figure 3 This is a cross-sectional view of track drive unit 1.

[0053] like Figure 2 , Figure 3 As shown, the track 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.

[0054] <Electric Motor>

[0055] The electric motor 2 includes a stator (not shown) fixed inside the motor housing 5 and a rotor 6 that is freely rotatable relative to the stator. The electric motor 2 is driven by power supplied from an external power source (battery) that is supplied to the vehicle body 101. Various types of motors that are driven by supplied electricity, such as brushed motors and brushless motors, can be used as the electric motor 2.

[0056] A connector 50 for supplying power to a stator (not shown) is provided on the outer peripheral surface of the motor housing 5. An external connector extending from an external power source (not shown) is connected to this connector 50. The connector 50 is provided with a socket 50a for connecting to the external connector (not shown).

[0057] The motor shaft 7 of the rotor 6 is rotatably supported on the motor housing 5. A portion of the motor shaft 7 protrudes from the motor housing 5 along the rotation axis Jm of the motor shaft 7. A spline is machined on the outer circumferential surface of the protruding tip 7a of the motor shaft 7. A transmission mechanism 3 is connected to the tip 7a. The socket 50a of the connector 50 provided to the motor housing 5 faces the side opposite to the tip 7a of the motor shaft 7.

[0058] The portion of the motor shaft 7 that protrudes from the motor housing 5 is surrounded by a cylindrical support housing 8. The support housing 8 protrudes from the motor housing 5 along the rotation axis Jm to the front of the top end 7a of the motor shaft 7. A sealing member 9 is provided on the inner circumferential surface of the support housing 8, on the side opposite to the motor housing 5. The sealing member 9 ensures a tight seal between the support housing 8 and the motor shaft 7. The opposite end of the support housing 8, on the side opposite to the motor housing 5, is also connected to the transmission mechanism 3.

[0059] <Transmission Mechanism>

[0060] The transmission mechanism 3 has a transmission side housing 10 and two spur gears 11 and 12 (first spur gear 11 and second spur gear 12) that are rotatably housed inside the transmission side housing 10.

[0061] The transmission-side housing 10 has a box-shaped housing body 21 with an opening on the side of the electric motor 2 and a sealing plate 22 that seals the opening 21a of the housing body 21. A support housing 8 is fixed to the sealing plate 22. A shaft through hole 13 is formed in the sealing plate 22 for the motor shaft 7 to pass through. The top end 7a of the motor shaft 7 is inserted into the housing body 21 through the shaft through hole 13.

[0062] A working oil inlet 23 is formed on the outer peripheral wall 21b of the housing body 21. A connection port 14 is formed on the bottom wall 21c of the housing body 21. A transmission-side oil passage 15 is formed on the housing body 21, connecting the working oil inlet 23 and the connection port 14 from the outer peripheral wall 21b to the bottom wall 21c. These working oil inlets 23, connection ports 14, and transmission-side oil passages 15 are used to inject lubricating oil into the reduction gear 4.

[0063] Two spur gears 11 and 12 are housed within the outer casing 21 in a meshing state. The first spur gear 11 is fitted and fixed to the top end 7a of the motor shaft 7. Due to the spline machining performed on the top end 7a, the motor shaft 7 and the first spur gear 11 rotate as a unit.

[0064] Of the two spur gears 11 and 12, the rotation axis Jh of the second spur gear 12 is parallel to the rotation axis Jm of the motor shaft 7, but offset radially from the motor shaft 7 (the second spur gear 12). The second spur gear 12 has more teeth than the first spur gear 11. Therefore, the rotation of the second spur gear 12 is slower relative to the rotation of the first spur gear 11.

[0065] One end 16a of the input shaft 16 (an example of the input section in the claim) of the reduction mechanism 4 is fitted and fixed to the second spur gear 12. This end 16a is splined, and the second spur gear 12 rotates integrally with the input shaft 16. The rotation axis Jn of the input shaft 16 coincides with the rotation axis Jh of the second spur gear 12. The rotation axis Jh of the second spur gear 12 is parallel to the rotation axis Jm of the motor shaft 7; therefore, the rotation axis Jn of the input shaft 16 is also parallel to the rotation axis Jm of the motor shaft 7.

[0066] The input shaft 16 is a solid shaft. The input shaft 16 is inserted into the housing body 21 from the reduction gear 4 side via a shaft through-hole 24 formed in the bottom wall 21c of the housing body 21. The shaft through-hole 24 is provided with: a sealing member 25, which seals the bottom wall 21c of the housing body 21 and the input shaft 16; and a bearing 26, which supports the input shaft 16 on the transmission mechanism 3 side, allowing for free rotation.

[0067] <Speed ​​Reduction Mechanism>

[0068] In addition to the input shaft 16, the reduction mechanism 4 also includes a reduction side housing 17 that supports the input shaft 16 for free rotation, and multi-stage (two-stage in this embodiment) gear mechanisms 18A and 18B (first-stage gear mechanism 18A and second-stage gear mechanism 18B) connected to the reduction side housing 17. In the following description of the reduction mechanism 4, the radial direction of the input shaft 16 will be simply referred to as radial.

[0069] The deceleration-side housing 17 is fixed to the bottom wall 21c of the housing body 21 that constitutes the transmission-side housing 10. The deceleration-side housing 17 is integrally formed with a base portion 19 that overlaps with the bottom wall 21c of the housing body 21 and a bearing housing 20 that protrudes from the base portion 19 toward the side opposite to the electric motor 2.

[0070] Multiple first fixing seats 27 are integrally formed on the outer peripheral surface 19a of the base portion 19, extending radially outward. The first fixing seats 27 are used to fix the track drive unit 1 to the running gear 102. A through hole 19b is formed in the base portion 19 for the input shaft 16 to pass through.

[0071] A recess 28 is formed in the bearing housing 20, which connects to the through hole 19b of the base portion 19. A shaft through hole 29, penetrating the bearing housing 20 in the direction of the rotation axis Jn, is formed at the bottom of the recess 28 (on the side opposite to the transmission mechanism 3). The other end 16b of the input shaft 16 protrudes through this shaft through hole 29 to the side opposite to the transmission mechanism 3. A bearing 30 is provided in the shaft through hole 29 for supporting the input shaft 16 in a rotationally free manner; and a sealing member 31 for sealing between the bearing housing 20 and the input shaft 16.

[0072] A parking brake 32 is provided in the recess 28 of the bearing housing 20. The parking brake 32 is used to prevent or release the rotation of the input shaft 16. The plate 32a constituting the parking brake 32 is always pressed by a spring (not shown). This prevents the rotation of the input shaft 16. When the parking brake 32 is released, working oil is supplied to it. As a result, the spring (not shown) is compressed and deformed due to the pressure of the working oil. Consequently, the pressure of the spring on the plate 32a is released, and the input shaft 16 is also released.

[0073] A deceleration-side oil passage 33 is formed on the outer peripheral wall 20a of the bearing housing 20, which connects the connection port 14 of the transmission-side housing 10 and the recess 28. Working oil from the outside is supplied to the recess 28 via this deceleration-side oil passage 33, the connection port 14 of the transmission-side housing 10, the transmission-side oil passage 15, and the working oil inlet 23. As a result, the parking brake 32 operates.

[0074] On the side of the bearing housing 20 opposite to the transmission mechanism 3, a plurality of second supports 49 are integrally formed in a protruding manner. These second supports 49 constitute parts of the gear mechanisms 18A and 18B.

[0075] Gear mechanisms 18A and 18B are coaxially arranged on the side of the bearing housing 20 opposite to the transmission mechanism 3, with respect to the rotation axis Jn. Gear mechanisms 18A and 18B are arranged from the side opposite to the transmission mechanism 3 toward the bearing housing 20 in the order of first-stage gear mechanism 18A and second-stage gear mechanism 18B.

[0076] 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, which is connected to the other end 16b of the input shaft 16 by means of a coupling 34; a first planetary gear 36, which meshes with the first sun gear 35; an internal gear 37, which meshes with the first planetary gear 36; and a first planetary gear carrier 38, which supports the first planetary gear 36.

[0077] The first sun gear 35 rotates integrally with the input shaft 16. Multiple first planetary gears 36 are provided (e.g., three). Each first planetary gear 36 is equally spaced around the first sun gear 35.

[0078] The internal gear 37 is formed in a cylindrical shape to surround the gear mechanisms 18A, 18B and the bearing housing 20. One end 37a of the internal gear 37, near the transmission mechanism 3, is close to 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 prevents grease (lubricating oil) filled into the internal gear 37 from leaking out from between the one end 37a of the internal gear 37 and the base portion 19.

[0079] An end plate 41 is provided at the other end 37b of the internal gear 37, opposite to the transmission mechanism 3, to block the opening 37c of the internal gear 37. On the outer peripheral surface of the internal gear 37, near the transmission side housing 10, a plurality of second fixing seats 42 are integrally formed in a radially outward manner. The second fixing seats 42 are used to transmit the driving force of the track drive unit 1 to the traveling unit 102 (details will be discussed later).

[0080] The internal gear 37, positioned corresponding to the bearing housing 20, is supported by two bearings 39a and 39b, allowing it to rotate freely relative to the bearing housing 20. Internal teeth 37d are formed on the internal gear 37 at positions corresponding to the gear mechanisms 18A and 18B. The first planetary gear 36 meshes with these internal teeth 37d.

[0081] A first planetary gear carrier 38 supporting the first planetary gear 36 is disposed on the bearing housing 20 side of the first planetary gear 36. On the first planetary gear carrier 38, a first support 43 is provided protruding on one side 38a facing the first planetary gear 36, supporting the first planetary gear 36 so that it can rotate freely. On the other side 38b of the first planetary gear carrier 38, a second sun gear 45 constituting the second-stage gear mechanism 18B is integrally disposed.

[0082] The second-stage gear mechanism 18B, in addition to the second sun gear 45, also includes a bridge gear 46 that meshes with the second sun gear 45 and an internal gear 37 that meshes with the bridge gear 46. The internal gear 37 is shared with the first-stage gear mechanism 18A. The second sun gear 45 is cylindrical. A coupling 34 is inserted into the second sun gear 45 in a manner that allows it to rotate relative to the second sun gear 45.

[0083] Multiple (e.g., three) of the bridge gears 46 are provided. Each bridge gear 46 is equally spaced around the second sun gear 45. These bridge gears 46 are rotatably supported by a second support column 49 integrally formed with the bearing housing 20.

[0084] Based on this structure, the track drive unit 1 is configured such that the internal gear 37 of the reduction mechanism 4 is controlled radially inside the drive wheel 108. The electric motor 2 is located inside the vehicle width direction relative to the reduction mechanism 4. A second mounting base 42 for the internal gear 37 is fixed to the drive wheel 108. The internal gear 37 rotates integrally with the drive wheel 108. On the other hand, a first mounting base 27 for the reduction side housing 17 is fixed to the track frame 107.

[0085] like Figure 1 As detailed, with the track drive unit 1 installed in the travel unit 102, the entire reduction mechanism 4 and the transmission mechanism 3 are substantially housed within the width of the travel unit 102 in the vehicle width direction. More specifically, in Figure 1 In the middle, only the blocking plate 22 of the transmission mechanism 3 protrudes from the driving part 102 inward in the vehicle width direction.

[0086] The rotation axis Jm of motor shaft 7 is located directly above the rotation axis Jn of input shaft 16 (the rotation axis Jh of the second spur gear 12). 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, motor housing 5, and support housing 8 that form the outline of the electric motor 2. "Above" refers to the direction of gravity, meaning the higher up one goes, the further away from the road surface one is. For a detailed explanation of the positional relationship between the electric motor 2 and the lower frame 104, see [link to relevant documentation]. Figure 1 In the middle, viewed from the front and back, the lower edge of the motor housing 5 is aligned with the bottom surface 104a.

[0087] <Action of the track drive unit>

[0088] Next, the operation of the track drive unit 1 will be explained.

[0089] like Figure 2 , Figure 3 As shown, the motor shaft 7 of the rotor 6 rotates by driving the electric motor 2. If the motor shaft 7 rotates, the rotation is transmitted to the input shaft 16 of the 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 reduced in speed by the two spur gears 11 and 12 and transmitted to the input shaft 16.

[0090] If the motor shaft 7 rotates, the first sun gear 35 rotates integrally with the motor shaft 7. The first planetary gear 36, which meshes with the first sun gear 35 and the internal gear 37, rotates on its own axis about the first support 43 and revolves around the first sun gear 35. The first planetary gear carrier 38, which supports the first planetary gear 36, rotates about the rotation axis Jn of the input shaft 16. The second sun gear 45 rotates integrally with the first planetary gear carrier 38. The second sun gear 45 is cylindrical, and a coupling 34 is inserted radially inside it; therefore, the rotation of the second sun gear 45 does not interfere with the rotation of the input shaft 16.

[0091] If the second sun gear 45 rotates, the intermediate gear 46, which meshes with the second sun gear 45 and the internal gear 37, rotates around the second support 49. Due to the rotation of the intermediate gear 46, the internal gear 37 rotates. The drive wheel 108 rotates integrally with the internal gear 37. That is, the internal gear 37 slows down the rotation of the motor shaft 7 and outputs power to the drive wheel 108.

[0092] As the drive wheel 108 rotates, the track 109 operates, and the construction machinery 100 moves. Thus, the reduction mechanism 4 transmits driving force to the track 109 via the drive wheel 108. The electric motor 2 provides driving force to the reduction mechanism 4 via the transmission mechanism 3.

[0093] In the track drive unit 1, the rotation axis Jm of the motor shaft 7 is located directly above the rotation axis Jn of the input shaft 16 (the rotation axis Jh of the second spur gear 12). The entire electric motor 2 is positioned above the bottom surface 104a of the lower frame 104.

[0094] Thus, the aforementioned track drive unit 1 allows the electric motor 2 to be positioned above the reduction gear 4. Therefore, even when the track drive unit 1, equipped with the electric motor 2 and the reduction gear 4, is installed in the travel section 102, and the electric motor 2 protrudes from the travel section 102 in the vehicle width direction, the position of the electric motor 2 can be kept as far away from the road surface as possible. Consequently, the possibility of the electric motor 2 coming into contact with sand, stones, etc., during the movement of the construction machinery 100 can be reduced. This results in a construction machinery 100 with high mobility.

[0095] In particular, by positioning the entire electric motor 2 above the bottom surface 104a of the lower frame 104, the possibility of the electric motor 2 coming into contact with sand, stones, etc., can be reliably reduced during the operation of the construction machinery 100.

[0096] By raising the position of the electric motor 2 as much as possible, working space can be ensured below the electric motor 2. Therefore, the maintainability of the track drive unit 1 can be improved.

[0097] The rotation axes Jm and Jn of the electric motor 2 (motor shaft 7) and the reduction mechanism 4 (input shaft 16), which are connected by the transmission mechanism 3, are parallel. Therefore, compared with the case where the rotation axes Jm and Jn intersect, the transmission efficiency of driving force from the electric motor 2 to the reduction mechanism 4 can be improved.

[0098] More specifically, the transmission mechanism 3 is configured such that two spur gears 11 and 12 mesh. By using the spur gears 11 and 12, the rotation of the motor shaft 7 can be transmitted to the input shaft 16 efficiently.

[0099] Furthermore, the second spur gear 12 has more teeth than the first spur gear 11. Therefore, the rotation of the second spur gear 12 is reduced relative to the rotation of the first spur gear 11. That is, in addition to using the reduction mechanism 4 to reduce the rotation of the motor shaft 7, the transmission mechanism 3 can also be used to reduce the rotation of the motor shaft 7. As a result, the track drive unit 1 can be miniaturized while obtaining a high reduction ratio, and the track drive unit 1 can provide high output.

[0100] With the track drive unit 1 installed on the travel section 102, the entire deceleration mechanism 4 and the transmission mechanism 3 are substantially housed within the width of the travel section 102 in the vehicle width direction. Therefore, the travel section 102 (drive wheel 108) can cover the area around the deceleration mechanism 4. Consequently, contact between the deceleration mechanism 4 and sand, stones, etc., can be suppressed. Therefore, the possibility of damage to the deceleration mechanism 4 can be reduced.

[0101] In the first embodiment described above, the position of the electric motor 2 above the bottom surface 104a of the lower frame 104 was explained. However, it is not limited to this; the electric motor 2 can be positioned above the rotation axis Jn of the input shaft 16. Even with this configuration, compared to the case where the rotation axis Jm of the motor shaft 7 and the rotation axis Jn of the input shaft 16 are on the same straight line, the position of the electric motor 2 can be positioned above the reduction mechanism 4. Therefore, it achieves the same effect as the first embodiment described above.

[0102] [Second Implementation]

[0103] Next, quote Figure 1 and based on Figure 4 , Figure 5 The second embodiment of the present invention will be described.

[0104] Figure 4 This is a plan view of the traveling section 102, lower frame 104, and track drive unit 201 in the second embodiment, viewed from the front and rear. Figure 5This is a partial schematic view of the traveling section 102 and track drive unit 201 in the second embodiment, viewed from the vehicle width direction. Figure 5 Equivalent to Figure 4 A view from direction A. Furthermore, in the following description, the same reference numerals are used to refer to the same features as in the first embodiment described above, and descriptions are omitted (the same applies to the third embodiment below).

[0105] In the second embodiment, the construction machinery 100 has the following components, etc. (see also) Figure 1 The vehicle body 101 is the same as described in the first embodiment (and also in the third embodiment below): a vehicle body 101; a travel unit 102 that enables the vehicle body 101 to travel; and a track drive unit 201 disposed in the travel unit 102 for driving the travel unit 102.

[0106] The difference between the first and second embodiments lies in the mounting orientation of the electric motor 2 in the track drive unit 1 of the first embodiment and the mounting orientation of the electric motor 2 in the track drive unit 201 of the second embodiment.

[0107] Specifically, such as Figure 4 , Figure 5 As shown, the electric motors 2 of the track drive units 201 installed in each traveling section 102 are offset relative to the reduction mechanism 4 in the longitudinal direction. Therefore, the two electric motors 2 are arranged in the longitudinal direction. The entire electric motor 2 is controlled on the projection plane of the traveling section 102. The rotation axis Jm of the motor shaft 7 of the track drive unit 201 and the rotation axis Jn of the input shaft 16 are aligned on the same horizontal line. In other words, the electric motor 2 and the reduction mechanism 4 are arranged at the same height.

[0108] By constructing in this way, for example, as Figure 4 As shown, even when the interval between the left and right travel units 102 is short, it is possible to prevent the track drive units 201 installed in each travel unit 102 from interfering with each other.

[0109] The track drive unit 201 can be improved in terms of versatility because it is not necessary to prepare a separate track drive unit 201 according to the different intervals of the left and right driving units 102.

[0110] [Modifications of the Second Embodiment]

[0111] Figure 6 This is a partial schematic view of the traveling section 102 and track drive unit 201 in the modified example of the second embodiment, viewed from the vehicle width direction. Figure 6 With the aforementioned Figure 5 Correspondingly.

[0112] In the second embodiment described above, the rotation axis Jm of the motor shaft 7 of the track drive unit 201 and the rotation axis Jn of the input shaft 16 are arranged on the same horizontal line. However, it is not limited to this, such as... Figure 6 As shown, the rotation axis Jm of the motor shaft 7 can also be located above the rotation axis Jn of the input shaft 16.

[0113] With this configuration, in addition to having the same effect as the second embodiment described above, it is also possible to reduce the possibility of the electric motor 2 coming into contact with sand, stones, etc. during the operation of the construction machinery 100.

[0114] [Third Implementation]

[0115] Next, based on Figure 7 The third embodiment of the present invention will be described.

[0116] Figure 7 This is a partial schematic view of the traveling section 102 and track drive unit 301 in the third embodiment, viewed from the vehicle width direction. Figure 7 With the aforementioned Figure 5 Correspondingly.

[0117] like Figure 7 As shown, the difference between the second and third embodiments lies in the fact that the transfer mechanism 3 of the second embodiment (first embodiment) is different from the transfer mechanism 303 of the third embodiment.

[0118] Specifically, the transmission mechanism 303 provides a third spur gear 60 between the first spur gear 11 and the second spur gear 12. The number of teeth on the third spur gear 60 may also be different from the number of teeth on the first spur gear 11 and the second spur gear 12. Alternatively, the number of teeth on the third spur gear 60 may be the same as the number of teeth on the first spur gear 11. In this third embodiment, the number of teeth on the third spur gear 60 is set to be the same as the number of teeth on the first spur gear 11.

[0119] The rotation axis Jm of the motor shaft 7 of the track drive unit 301 and the rotation axis Jn of the input shaft 16 are aligned on the same horizontal line. In other words, the electric motor 2 and the reduction mechanism 4 are positioned at the same height.

[0120] Therefore, according to the third embodiment described above, the same effect as that of the second embodiment described above is achieved. The transmission mechanism 303 is composed of three spur gears 11, 12, and 60, thus allowing the position of the rotation axis Jm of the motor shaft 7 to deviate significantly from the position of the rotation axis Jn of the input shaft 16. Correspondingly, this increases the degree of freedom in the layout of the track drive unit 301.

[0121] 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 second spur gear 12, the reduction ratio can be increased using the transmission mechanism 303. Therefore, the track drive unit 301 can be miniaturized while obtaining a higher reduction ratio, and the track drive unit 301 can provide high output.

[0122] In the third embodiment described above, the transmission mechanism 303 is described as consisting of three spur gears 11, 12, and 60. However, it is not limited to this, and the transmission mechanism 303 may also be consisting of four or more spur gears.

[0123] [Modifications of the Third Embodiment]

[0124] Figure 8 This is a partial schematic view of the traveling section 102 and track drive unit 301 in the modified example of the third embodiment, viewed from the vehicle width direction. Figure 8 With the aforementioned Figure 7 Correspondingly.

[0125] In the third embodiment described above, the rotation axis Jm of the motor shaft 7 of the track drive unit 301 and the rotation axis Jn of the input shaft 16 are arranged on the same horizontal line. However, it is not limited to this, such as... Figure 8 As shown, the rotation axis Jm of the motor shaft 7 can also be located above the rotation axis Jn of the input shaft 16.

[0126] With this configuration, in addition to having the same effect as the third embodiment described above, it is also possible to reduce the possibility of the electric motor 2 coming into contact with sand, stones, etc. during the operation of the construction machinery 100.

[0127] The structure of the transmission mechanism 303 in the third embodiment described above can also be applied to the transmission mechanism 3 in the first embodiment described above. With this configuration, the electric motor 2 can be positioned further above the reduction mechanism 4. Therefore, the possibility of the electric motor 2 coming into contact with sand, stones, etc., during the movement of the construction machinery 100 can be further reduced. It can also become a construction machinery 100 with higher mobility.

[0128] This invention is not limited to the embodiments described above, but includes embodiments that are modified from the above embodiments without departing from the spirit of this invention.

[0129] For example, in the above embodiment, the track drive units 1, 201, and 301 for driving the travel unit 102 mounted on the construction machinery 100 have been described. However, this is not a limitation, and the track drive units 1, 201, and 301 described above can be applied to various devices that mount the travel unit 102.

[0130] In the above embodiment, the case where the traveling unit 102 includes a track frame 107, idler wheels, drive wheels (sprockets) 108, rollers, and tracks 109 that are wound around these idler wheels, drive wheels 108, and rollers has been described. However, it is not limited to this, and the traveling unit 102 can be a structure in which the tracks 109 work due to the rotation of the drive wheels 108, thereby allowing the construction machinery 100 to travel.

[0131] In the above embodiments, the transmission mechanisms 3 and 303 were described as being composed of multiple spur gears 11, 12, and 60. However, they are not limited to this; the transmission mechanisms 3 and 303 can be any structure capable of transmitting the rotation of the motor shaft 7 of the electric motor 2 to the input shaft 16 of the reduction mechanism 4. For example, the transmission mechanisms 3 and 303 can also be composed of pulleys and timing belts. For example, the transmission mechanisms 3 and 303 can also be composed of sprockets and chains.

[0132] For example, a free joint (universal joint) can also be used as the transmission mechanism. In this case, it is not necessary for the rotation axis Jm of the motor shaft 7 to be parallel to the rotation axis Jn of the input shaft 16. Even if the rotation axis Jm of the motor shaft 7 intersects with the rotation axis Jn of the input shaft 16, the motor shaft 7 can be positioned slightly above the rotation axis Jn of the input shaft 16. This configuration achieves the same effect as the embodiment described above.

[0133] In the above embodiments, the case where the rotation of the motor shaft 7 is reduced by using the transmission mechanisms 3 and 303 has been described. However, it is not limited to this; the transmission mechanisms 3 and 303 can be any structure capable of transmitting the rotation of the motor shaft 7 to the reduction mechanism 4. For example, the transmission mechanisms 3 and 303 can also be configured to transmit the rotation of the motor shaft 7 at a constant speed or at an increased speed to the reduction mechanism 4.

[0134] In the above embodiments, the case where the input part in the claims is the input shaft 16 has been described. However, it is not limited to this; the input part can simply have the function of inputting the rotation of the electric motor 2 to the reduction mechanism 4. For example, the input shaft 16 can be a solid shaft, but it can also be a hollow shaft instead of a solid shaft.

[0135] In the above embodiments, the reduction mechanism 4 is described as having two-stage gear mechanisms 18A and 18B. The first-stage gear mechanism 18A is described as a planetary gear mechanism, comprising a first sun gear 35, a first planetary gear 36, an internal gear 37, and a first planetary gear carrier 38. The second-stage gear mechanism 18B is described as comprising a second sun gear 45, a bridge gear 46, and an internal gear 37. However, it is not limited to this; the reduction mechanism 4 can be a structure that reduces the rotation of the motor shaft 7 of the electric motor 2 and outputs the deceleration. For example, multiple spur gears can mesh such that the rotation axis of the input section is offset from the rotation axis of the output section (output side).

[0136] In the above embodiment, the case where the reduction mechanism 4 transmits the rotation of the motor shaft 7 of the electric motor 2, which is transmitted via 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; any method that can transmit the rotation of the motor shaft 7 to the drive wheel 108 using the reduction mechanism 4 is acceptable. That is, in the case where, for example, the reduction mechanism is composed of multiple spur gears, the rotation of the motor shaft 7 can be transmitted from the final spur gear to the drive wheel 108.

[0137] In the above embodiment, the case where the electric motor 2 protrudes from the travel section 102 in the vehicle width direction has been described. However, it is not limited to this. Even if, for example, the track drive units 1, 201, and 301 can be housed within the travel section 102 and the electric motor 2 does not protrude from the travel section 102 in the vehicle width direction, the structure of the track drive units 1, 201, and 301 described above can still be used. However, when the electric motor 2 protrudes from the travel section 102 in the vehicle width direction, the structure of the track drive units 1, 201, and 301 described above is preferable.

[0138] In the above embodiments, the case where the internal gear 37 of the reduction mechanism 4 of the track drive units 1, 201, and 301 is integrally provided with the drive wheel 108 has been described. The case where the internal gear 37 and the drive wheel 108 rotate integrally has also been described. However, this is not a limitation; the track 109 can operate using the output of the reduction mechanism 4. For example, it may be configured such that the internal gear 37 functions as the drive wheel 108 by winding the track 109 around itself.

[0139] In the embodiments disclosed in this specification, a component composed of multiple objects can either be integrated into one object, or the component composed of a single object can be divided into multiple objects. Regardless of whether they are integrated or not, they can be configured in a manner that achieves the purpose of the invention.

Claims

1. A tracked drive unit, comprising: A deceleration mechanism is provided in the traveling section that enables the main body of the vehicle to move, and transmits driving force to the tracks provided in the traveling section; A transmission mechanism that transmits the driving force to the reduction mechanism; and An electric motor imparts rotational force to the transmission mechanism. The electric motor has the following features: Motor housing; A motor shaft that protrudes from the motor housing; as well as A support housing, which protrudes from the motor housing in the same direction as the motor shaft, is formed in a cylindrical shape to cover the periphery of the motor shaft, thereby supporting the motor shaft for free rotation. The deceleration mechanism includes an input section from which the driving force is input from the transmission mechanism. The motor shaft is located above the rotation axis of the input section. The end of the support housing opposite to the motor housing is fixed to the transmission mechanism. The support housing, the transmission mechanism, and the deceleration mechanism are arranged sequentially from the inside to the outside in the width direction of the vehicle body.

2. The track drive unit according to claim 1, wherein, The rotation axis of the motor shaft is parallel to the rotation axis of the input section.

3. The track drive unit according to claim 1 or 2, wherein, The electric motor is arranged to protrude from the reduction gear in the width direction of the vehicle body.

4. The track drive unit according to claim 1 or 2, wherein, The transmission mechanism includes multiple meshing gears.

5. The track drive unit according to claim 1 or 2, wherein, The transmission mechanism slows down the rotation of the motor shaft and transmits the rotation to the input section.

6. The track drive unit according to claim 1 or 2, wherein, The electric motor is located above the rotation axis of the input section.

7. The track drive unit according to claim 1 or 2, wherein, The lower part of the electric motor is aligned with the bottom surface of the vehicle body, or the entire electric motor is positioned above the bottom surface of the vehicle body.

8. The track drive unit according to claim 1 or 2, wherein, At least a portion of the deceleration mechanism is housed within a region of the vehicle body in the width direction that is included in the tracks.

9. A tracked drive unit, comprising: A deceleration mechanism is provided in the traveling section that enables the main body of the vehicle to move, and transmits driving force to the tracks provided in the traveling section; A transmission mechanism that transmits the driving force to the deceleration mechanism; as well as An electric motor, which is arranged to protrude from the reduction gear in the width direction of the vehicle body, imparts rotational force to the reduction gear. The electric motor has the following features: Motor housing; A motor shaft that protrudes from the motor housing; as well as A support housing, which protrudes from the motor housing in the same direction as the motor shaft, is formed in a cylindrical shape to cover the periphery of the motor shaft, thereby supporting the motor shaft for free rotation. The transmission mechanism reduces the rotational speed of the motor shaft and transmits the speed to the reduction mechanism. The lower part of the electric motor is aligned with the bottom surface of the vehicle body, or the entire electric motor is positioned above the bottom surface of the vehicle body. The end of the support housing opposite to the motor housing is fixed to the transmission mechanism. The support housing, the transmission mechanism, and the deceleration mechanism are arranged sequentially from the inside to the outside in the width direction of the vehicle body.

10. A tracked drive unit, comprising: Two reduction gears are provided on the left and right driving parts that enable the main body of the vehicle to move, and transmit driving force to the tracks provided on each of the driving parts; Two transmission mechanisms that transmit the driving force to the two reduction mechanisms; as well as Two electric motors, which are arranged to protrude inward from the two reduction gears in the width direction of the vehicle body, impart rotational force to the two reduction gears. The two electric motors are arranged in a front-rear direction on the vehicle body. Each of the two electric motors has: Motor housing; A motor shaft that protrudes from the motor housing; as well as A support housing, which protrudes from the motor housing in the same direction as the motor shaft, is formed in a cylindrical shape to cover the periphery of the motor shaft, thereby supporting the motor shaft for free rotation. The end of the support housing opposite to the motor housing is fixed to the transmission mechanism. The support housing, the transmission mechanism, and the deceleration mechanism are arranged sequentially from the inside to the outside in the width direction of the vehicle body.

11. The track drive unit according to claim 10, wherein, The two reduction mechanisms each have an input section from which the driving force is input from the transmission mechanism, and the motor shaft is located above the rotation axis of the input section.

12. A construction machine, comprising: Vehicle body; A driving unit that enables the vehicle body to move; A deceleration mechanism is provided on the traveling unit and transmits driving force to the tracks provided on the traveling unit; A transmission mechanism that transmits the driving force to the deceleration mechanism; as well as An electric motor, which is arranged to protrude from the reduction gear in the width direction of the vehicle body, imparts rotational force to the reduction gear. The electric motor has the following features: Motor housing; A motor shaft that protrudes from the motor housing; as well as A support housing, which protrudes from the motor housing in the same direction as the motor shaft, is formed in a cylindrical shape to cover the periphery of the motor shaft, thereby supporting the motor shaft for free rotation. The transmission mechanism reduces the rotational speed of the motor shaft and transmits the speed to the reduction mechanism. The lower part of the electric motor is aligned with the bottom surface of the vehicle body, or the entire electric motor is positioned above the bottom surface of the vehicle body. The end of the support housing opposite to the motor housing is fixed to the transmission mechanism. The support housing, the transmission mechanism, and the deceleration mechanism are arranged sequentially from the inside to the outside in the width direction of the vehicle body.

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