JP2007153038A - Transmission for working vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transmission for a working vehicle capable of reducing the cost by reducing the number of parts of a planetary gear mechanism. <P>SOLUTION: The transmission for the working vehicle is equipped with a pair of driving sources 35L, 35R attached to a transmission case 31, and a differential mechanism 34 having planetary gear mechanisms 33L, 33R composed in the transmission case 31. A driving force from an engine 15 is transmitted to a pair of right and left axles 21R, 21L through a differential mechanism 34, and the driving force from driving sources 35L, 35R is transmitted to the axles 21L, 21R through planetary gear mechanisms 35L, 35R from gears 60L, 60R meshing with outer gears 75L, 75R provided in the planetary gear mechanisms 33L, 33R. Internal gears 53L, 53R composing the planetary gear mechanisms 33L, 33R are disposed in the vertical direction of the inner side end parts 40 of the axles 21L, 21R. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transmission for a work vehicle such as a snowplow and an agricultural machine, and more specifically, a differential having a pair of left and right planetary gear mechanisms configured in a transmission case, with power from an engine and power from a drive source. The present invention relates to an arrangement configuration of an axle and a planetary gear mechanism in a transmission that transmits to a pair of left and right axles via a mechanism.

  Conventionally, in a transmission of a work vehicle such as a snowplow and an agricultural machine, a driving force from an engine or the like is passed through a differential mechanism through a continuously variable transmission such as an HST (hydraulic continuously variable transmission). Further, there is a configuration that transmits to each axle of a pair of left and right traveling devices. And about such a transmission, there exists a thing of the structure arrange | positioned below with respect to the engine mounted on the body frame of a working vehicle (refer patent document 1).

  For such a work vehicle transmission, a pair of output shafts (axles) protruding in the left-right direction from the transmission case are differentially coupled by a differential mechanism housed in the transmission case and having a pair of left and right planetary gear mechanisms. In this differential mechanism, the driving force from the engine and the driving force from the driving source are combined, and the driving force from the driving source is used to assist the turning of the work vehicle and the driving force (running driving force) from the engine. The structure used as is studied (see Patent Documents 2 and 3).

When such a configuration is adopted, the driving force from the engine is uniformly applied to the left and right planetary gear mechanisms of the differential mechanism so as to drive the left and right axles at the same rotational speed, such as through a transmission such as an HST. The driving force from the driving source drives the left and right axles at different rotational speeds via a worm gear fixed to the output shaft of the driving source and a worm wheel provided to each planetary gear mechanism ( It is conceivable that the left and right planetary gear mechanisms are arbitrarily selected and transmitted so as to be differentially transmitted. In other words, a pair of drive sources that transmit driving force to each of the pair of left and right planetary gear mechanisms are provided, and the worm gear fixed to the output shaft of each drive source is a worm wheel provided in the planetary gear mechanism on the corresponding side. It is meshed so that the driving force from the driving source is transmitted to the corresponding planetary gear mechanism.
JP 2000-54335 A JP 2005-199755 A JP 2005-262909 A

  However, in the configuration of the conventional planetary gear mechanism, since the output shaft of the drive source is arranged in the front-rear direction of the inner end of the axle, when the axle is subjected to a load and is bent, it is fitted to the axle. The gears shifted and tilted in the vertical direction, resulting in poor tooth contact and possible wear. Therefore, in order to prevent the carrier from tilting, it is necessary to take measures such as providing a shaft support collar, which leads to an increase in cost and parts.

  In view of the above problems, the present invention provides a transmission for a work vehicle aimed at reducing costs by reducing the number of parts of the planetary gear mechanism.

  The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

  That is, in claim 1, a pair of drive sources attached to the mission case and a differential mechanism having a pair of left and right planetary gear mechanisms configured in the mission case, the driving force from the engine is The planetary gear on the side corresponding to the drive source is transmitted to the pair of left and right axles via the differential mechanism, and the driving force from each drive source is passed through the reduction element provided in the planetary gear mechanism. A transmission of a work vehicle that transmits to the axle on the side corresponding to the planetary gear mechanism via a mechanism, in which an internal gear constituting the planetary gear mechanism is arranged in the vertical direction of the inner end portion of the axle It is.

  As effects of the present invention, the following effects can be obtained.

  According to the first aspect of the present invention, the inner end portion of the axle is disposed in a direction perpendicular to one input side gear of the planetary gear mechanism, so that the carrier is less inclined and the contact of the planetary gear is improved. In addition, since it is not necessary to provide a shaft support collar or the like, the cost can be reduced.

Embodiments of the present invention will be described with reference to the drawings.
1 is a side view showing the overall configuration of a snowplow according to an embodiment of the present invention, FIG. 2 is a schematic view showing a driving force transmission path of the snowplow, and FIG. 3 is a side view of the transmission. 4 is a front view of the transmission, FIG. 5 is a plan view of the transmission, FIG. 6 is a partial rear sectional view showing the inner structure of the transmission, FIG. 7 is a partial sectional side view showing the inner structure of the transmission, and FIG. FIG. 9 is a partial plan view showing the internal structure of the transmission. FIG. 9 is a partial plan view showing the internal structure of the transmission.
First, an overall configuration of a walking snowplow (hereinafter referred to as “snowblower”) 1 as an embodiment of a work vehicle according to the present invention will be described with reference to FIGS. 1 and 2. The work vehicle according to the present invention is not limited to a snowplow, and may be a work vehicle such as a tractor, a management machine, or a mower.

  The snowplow 1 includes a working unit 2 that performs a snowplow operation, a drive unit 3 that supplies power to each drive unit of the snowplow 1, a pair of left and right traveling devices 4 that cause the snowplow 1 to travel, and the operation of the snowplow 1. The operation unit 5 is operated and is supported by the body frame 6. A transmission 30 that transmits the driving force from the driving unit 3 to the traveling device 4 is accommodated in the rear part of the body frame 6.

  The working unit 2 is disposed on the front side of the machine body frame 6 and removes snow existing on the travel route of the snow removal machine 1. The working unit 2 includes a scraping auger 10 for scraping snow, a blower 11 for discharging the scraped snow, a housing 12 surrounding the scraping auger 10 and housing the blower 11, and a snow discharge pipe. It consists of a certain shooter 13 or the like. That is, a scraping auger 10 is disposed at the front end of the snowplow 1, a blower 11 is disposed at the rear of the housing 12, and a shooter 13 is erected on the top of the housing 12.

  In the working unit 2, the snow in front of the snowplow 1 is scraped by the scraping auger 10, and the snow is transported into the housing 12 and is blown off by the blower 11 through the shooter 13. In this way, snow on the travel route of the snow removal machine 1 is removed. Here, the shooter 13 is configured to be rotatable on a horizontal plane with respect to the housing 12, and a tip end portion thereof is configured to be vertically rotatable. Thereby, it has the structure which can adjust the fall position to the ground of the snow jumped off from the blower 11 via the shooter 13. FIG. In addition, although illustration is omitted, in the snowplow 1, a lifting device such as a hydraulic cylinder is provided in the body frame 6, and the working unit 2 is configured to be lifted and lowered by operating this lifting device. Yes.

  The drive unit 3 includes an engine 15 disposed on the body frame 6 and placed via a support device 14 such as a vibration isolator. The drive unit 3 includes a generator 16 that generates power using the output of the engine 15 and a battery 17 that charges the power generated by the generator 16. The generator 16 and the battery 17 shown in FIG. 2 are provided by being fixed to the body frame 6 or the like.

  The engine 15 is a drive source of the snowplow 1, and the driving force from the engine 15 is transmitted to the scraping auger 10 and the blower 11 of the working unit 2 and to the traveling device 4. In addition, the engine 15 rotates the generator 16 to generate electric power. The electric power generated by the generator 16 is supplied to a drive source (left and right electric motors 35L and 35R in this embodiment) provided in the transmission 30, or the battery 17 is charged. That is, the electric power from the generator 16 or the battery 17 is supplied to the drive circuits (inverters) 36L and 36R of the electric motors 35L and 35R, and the electric motors 35L and 35R are driven while the rotational speed is controlled. The electric motors 35L and 35R are controlled by using a control circuit 37 to which the drive circuits 36L and 36R are connected.

  The engine 15 has an output shaft 15a that protrudes forward of the machine body. The output shaft 15a is provided with two engine pulleys 43a and 43b arranged at the front and rear, and a rear engine pulley 43a is provided. The driving force is transmitted to the traveling device 4, and the front engine pulley 43 b is used to transmit the driving force to the working unit 2.

  Specifically, in the body frame 6, a driving force transmission shaft 28 a for transmitting the driving force from the engine 15 to the transmission 30 is installed in the longitudinal direction of the body, and is provided at the front end of the driving force transmission shaft 28 a. An input pulley 47a is provided, and a belt 48a is wound around the input pulley 47a and the engine pulley 43a. On the other hand, from the machine body frame 6 to the housing 12 of the working unit 2, a driving force transmission shaft 28 b for transmitting the driving force from the engine 15 to the blower 11 and the take-up auger 10 of the working unit 2 extends in the longitudinal direction of the machine body. An input pulley 47b is provided at the rear end of the driving force transmission shaft 28b, and a belt 48b is wound around the input pulley 47b and the engine pulley 43b. That is, the driving force transmission shaft 28b transmits the driving force to the blower 11 disposed in the middle of the driving force transmission shaft 28b, and the gear box 29 is configured at the tip portion. In the gear box 29, the rotation of the driving force transmission shaft 28b is performed. The axial direction is converted into the left-right direction of the machine body by a bevel gear or the like, and the driving auger 10 is driven.

  The traveling device 4 includes a pair of left and right crawler traveling devices 4L and 4R. Each of the crawler type traveling devices 4L and 4R includes a drive sprocket 18 disposed on the rear side, a driven sprocket 19 disposed on the front side, a crawler belt 20 that is an endless belt wound around these, and the like. The drive sprocket 18 is externally fitted and fixed to the tip end portions (outer end portions) of the axles 21L and 21R, which are the drive shafts of the crawler type traveling devices 4L and 4R, protruding from the transmission 30 to the left and right sides of the machine body. The left and right axles 21L and 21R are arranged on the same axis so that the axial direction thereof is the left-right direction of the fuselage. The driven sprocket 19 is externally fitted and fixed to the driven shaft 22 rotatably supported at the front portion of the body frame 6 on both the left and right sides. In such a configuration, the left crawler traveling device 4L is driven by the rotation of the left axle 21L, and the right crawler traveling device 4R is driven by the rotation of the right axle 21R. In the present embodiment, the pair of left and right traveling devices 4 is a crawler traveling device, but is not limited to this and may be a foil type.

  The driving operation unit 5 includes left and right handles 23 extending from the left and right sides on the body frame 6 to the upper and rear sides, a turning lever 24 provided on the handle 23, and an operation unit frame standing on the rear of the body frame 6. 25, a working unit clutch lever 27 (see FIG. 2) for connecting / disconnecting transmission of driving force to the working unit 2, and a working unit for operating the lifting device to move the working unit 2 up and down. An elevating lever (not shown) is provided.

  An operator operates the snowplow 1 with a gripping portion 23 a provided at the tip of the left and right handles 23. Here, when the operator operates the turning lever 24 provided on the left and right handles 23 (holds the turning lever 24 together with the gripping portion 23a), the drive sprocket 18 on the side of the operated turning lever 24 is decelerated, The snowplow 1 is turned to the side. That is, when the operator operates the snowplow 1 by holding the grip portions 23 a of the left and right handles 23, the operator turns the snowplow 1 by operating the left and right turning levers 24 and operates the main transmission lever 26. Thus, the traveling speed of the snowplow 1 is adjusted.

  Specifically, the turning lever 24 is connected to the control circuit 37, and the control circuit 37 detects the operation amount (turning angle) of the turning lever 24, and based on this, the drive circuits 36L and 36R are controlled. The electric motors 35L and 35R are controlled through this. That is, the snowplow 1 is turned by the left and right electric motors 35L and 35R being differentially operated. The main transmission lever 26 is connected to a control circuit 37 via a potentiometer 26a that detects the lever position of the main transmission lever 26. That is, when the main transmission lever 26 is operated, the position of the lever is detected by the potentiometer 26a, and the driving force transmitted from the engine 15 to the traveling device 4 is changed via the control circuit 37. It should be noted that the left and right electric motors 35L and 35R assist driving of the traveling device 4 with the main speed change operation (at the same speed (number of rotations when both the turning levers 24 are not operated)). Also good. On the other hand, the working unit clutch lever 27 is connected to a working unit clutch 38 that turns on and off the driving force from the engine 15 to the working unit 2, and when the working unit clutch lever 27 is operated, The drive is operated. Note that the configuration and arrangement of the various levers in the driving operation unit 5 are not limited to the present embodiment.

Next, the transmission 30 will be described with reference to FIGS.
The transmission 30 transmits the driving force from the engine 15 and the electric motors 35L and 35R, which are electric motors, to the left and right crawler type traveling devices 4L and 4R, and makes the snowplow 1 go straight (forward / reverse) or turn left and right. is there. At this time, the transmission 30 adjusts the rotational speeds of the left and right traveling devices 4 to enable the snowplow 1 to go straight and smoothly turn.

  The transmission 30 includes a transmission case 31, a hydraulic continuously variable transmission (hereinafter referred to as "HST") 32, a differential mechanism 34 having a pair of left and right planetary gear mechanisms 33L and 33R, and a pair of left and right electric motors. Motors 35L and 35R are provided. That is, the transmission 30 includes a differential mechanism 34 having a pair of left and right planetary gear mechanisms 33L and 33R in the transmission case 31, and the driving force from the engine 15 and the electric motors 35L and 35R is supplied to the differential mechanism 34. Then, it transmits to each axle 21L * 21R which is a drive shaft of a pair of left and right crawler type traveling devices 4L * 4R supported rotatably in the transmission case 31 via a plurality of bearings 39L * 39R.

The mission case 31 functions as a housing that accommodates the components of the transmission 30 and prevents dust and the like from entering the inside thereof, and also serves as a structure that supports (axially supports) the components in the interior. It has a function.
The transmission case 31 has a split surface perpendicular to the rotation axis of the axles 21L and 21R, and is configured to be separably joined to the two case elements 31L and 31R. An attachment surface for installing and supporting the electric motors 35L and 35R is formed on the front surface of the case elements 31L and 31R, and on the rear surface of one of the case elements 31L and 31R, A mounting surface for installing and supporting the HST 32 is formed. In the present embodiment, the mounting surface of the HST 32 is formed on the upper rear surface of the case element 31R.

  Next, the HST 32 is a continuously variable transmission that shifts the driving force transmitted from the engine 15 and transmits it to the differential mechanism 34. The HST 32 is mounted on the mounting surface formed on the rear upper surface of the case element 31R of the transmission case 31. It is attached. The HST 32 includes a center section, a hydraulic pump 41, a hydraulic motor 42, and the like. The center section is provided with attachment surfaces to which the hydraulic pump 41 and the hydraulic motor 42 are respectively attached. The attachment portions are provided with the hydraulic pump 41 and the hydraulic motor 42, respectively. A hydraulic pump 41 is disposed on the right side and a hydraulic motor 42 is disposed on the left side via the center section. An oil passage is formed in the center section, and the hydraulic pump 41 and the hydraulic motor 42 are fluidly connected through the oil passage.

  The hydraulic pump 41 is a so-called movable swash plate type axial piston pump, and is provided with an input shaft (pump shaft) 41a, a cylinder block that is fitted to the input shaft 41a so as not to rotate relative to the input shaft 41a, and the cylinder block. A plurality of pistons accommodated in a plurality of cylinder holes so as to be slidably contacted via biasing springs, and a movable swash plate acting as a swash plate cam for reciprocatingly driving these pistons. That is, a cylinder block is attached to the attachment surface formed in the center section, and a plurality of pistons in the cylinder block rotate while contacting the movable swash plate, thereby passing through an oil passage formed in the center section. Thus, the pressure oil is conveyed to the hydraulic motor 42. The movable swash plate is configured so that the angle of the plate surface with respect to the axial direction of the input shaft 41a can be changed. When the plate surface of the movable swash plate is perpendicular to the axial direction of the input shaft 41a, Even when the shaft 41a is rotationally driven, the hydraulic oil 42 is in a neutral state where no hydraulic oil is conveyed, and the plate surface of the movable swash plate is also tilted from a state perpendicular to the axial direction of the input shaft 41a. Thus, the pressure oil is conveyed to the hydraulic motor 42 in conjunction with the rotational drive of the input shaft 41a. Here, by adjusting the tilt angle of the movable swash plate, the amount of pressure oil conveyed while the input shaft 41a rotates once is adjusted, and the rotation speed and rotation of the output shaft 42a of the hydraulic motor 42 described later are adjusted. The direction is adjusted.

In the hydraulic pump 41, a control shaft 41e for tilting the movable swash plate is pivotally supported in the vertical direction with its upper end protruding. The control shaft 41e has a lower end portion in the transmission case 31 connected to a movable inclined plate via a swing arm or the like, and an upper protruding portion connected to an electric motor 82 for operating the HST 32. (See FIG. 1).
The electric motor 82 is for operating the HST 32 and is attached to the rear upper surface of the transmission 30. That is, the electric motor 82 is attached to the upper surface of the HST 32. Then, the electric power from the generator 16 or the battery 17 is supplied to the drive circuit (inverter) 88 of the electric motor 82, and the electric motor 82 is driven while its rotational speed is controlled. The electric motor 82 is controlled by using a control circuit 37 to which the drive circuit 88 is connected.

The hydraulic motor 42 is a so-called fixed swash plate type axial piston motor. The hydraulic motor 42 has an output shaft (motor shaft) 42a, a cylinder block fitted to the output shaft 42a so as not to rotate relative thereto, and a hole formed in the cylinder block. A plurality of pistons accommodated in a plurality of cylinder holes so as to be slidably contacted with each other through biasing springs, and a reciprocating driving force of the pistons by pressure oil conveyed from the hydraulic pump 41 is used to drive the output shaft 42a to rotate. And a fixed swash plate 42d acting as a swash plate cam for converting the force.
That is, a cylinder block is attached to an attachment surface formed in the center section, and a plurality of pistons in the cylinder block rotate while contacting the fixed swash plate 42d, whereby the output shaft 42a rotates.

  The input shaft 41a of the hydraulic pump 41 serves as an input shaft for inputting the driving force from the engine 15 to the transmission 30, and the input shaft 41a protrudes toward the front of the body with the longitudinal direction of the body as the axial direction. . The output shaft 42a of the hydraulic motor 42 has an axial direction in the longitudinal direction of the machine body in the mission case 31, and a bevel gear 49 is fixed to the front end of the output shaft 42a.

  As shown in FIG. 6 and the like, the differential mechanism 34 differentially connects the left and right axles 21L and 21R in the traveling device 4, and is transmitted from the engine 15 to the axles 21L and 21R via the HST 32. The driving force and the driving force from the electric motors 35L and 35R are combined and transmitted. As described above, the driving force and the pair of left and right planetary gear mechanisms 33L and 33R are provided. Is done. The inner side in the axial direction on the axles 21L and 21R refers to the inside of the transmission case 31 (the right side of the left axle 21L and the left side of the right axle 21R) on each axle 21L and 21R. The axially outer side refers to the drive sprocket 18 side (left side of the left axle 21L, right side of the right axle 21R) on each axle 21L / 21R.

  The planetary gear mechanisms 33L and 33R are respectively relative to the sun gears 51 provided on the sun gear shaft 50 disposed between the left and right axles 21L and 21R on the same axis as the axles 21L and 21R, and the axles 21L and 21R. Carriers 52L and 52R that are rotatably supported, internal gears 53L and 53R that are rotatably supported on the axles 21L and 21R independently of the carriers 52L and 52R, and the carriers 52L and 52R. A plurality of planetary gears 54L and 54R that are pivotally supported by each other, and these planetary gears 54L and 54R mesh with the sun gear 51 on the axles 21L and 21R, respectively, and also have internal gears 53L and 54L. Engage with 53R.

  In other words, the sun gear shaft 50 constitutes the sun gear 51 that is the center of rotation of the left and right planetary gear mechanisms 33L and 33R, and is constructed between the planetary gear mechanisms 33L and 33R and the left and right axles 21L and 21R. It is arranged on the same axis and is rotatably supported. The sun gear 51 is integrally formed on the sun gear shaft 50. However, the sun gear 51 is not configured to be integrally formed on the sun gear shaft 50, but is separately provided at both ends of the sun gear shaft 50 so as to mesh with the planetary gears 54L and 54R in the planetary gear mechanisms 33L and 33R. It may be a body configuration. In addition, a center sprocket 44 that is an input gear of the sun gear shaft 50 is pivotally supported at the intermediate portion of the sun gear shaft 50 by spline fitting or the like so as not to be relatively rotatable. The support structure of the sun gear shaft 50 and the arrangement structure of the center sprocket 44 will be described later.

  Further, the carriers 52L and 52R are members formed in a substantially annular shape, and are inner end portions 40 in the respective axial directions on the left and right axles 21L and 21R, that is, the right end portion of the left axle 21L and the right axle. By being spline-fitted to the left end portion of 21R, it is supported so as not to rotate relative to axles 21L and 21R, and rotates integrally with axles 21L and 21R.

  Further, the internal gears 53L and 53R are outside the carriers 52L and 52R in the axial direction on the axles 21L and 21R, that is, on the left side of the carrier 52L on the left axle 21L and on the right side of the carrier 52R on the right axle 21R. Each is provided, and is rotatably supported on the same axis as the carriers 52L and 52R. The internal gears 53L and 53R have a gear portion 53a on the inner peripheral side thereof, and outer gears 75L and 75R described later are formed on the outer peripheral side. That is, the internal gears 53L and 53R are formed in a substantially annular shape, and the outer gears 75L and 75R are formed on the outer peripheral surface. In addition, the carriers 52L and 52R are accommodated in the inner peripheral portion, and the movement in the axial direction is restricted by the carriers and is fixed so as to be rotatable. A gear portion 53a of the internal gears 53L and 53R is formed on the inner side in the axial direction, that is, on the right side of the carrier 52L on the left axle 21L and on the left side of the carrier 52R on the right axle 21R.

  In addition, a plurality of planetary gears 54L and 54R are arranged radially at equal intervals with respect to the axes of the axles 21L and 21R in the planetary gear mechanisms 33L and 33R (only one is shown in FIG. 6 and the like), and are substantially annular carriers. Rotating shafts 59L, 52L, 52R that have the same axial direction as the axles 21L, 21R and project inward in the axial direction (right side in the left planetary gear mechanism 33L, left side in the right planetary gear mechanism 33R) It is rotatably supported with respect to the carriers 52L and 52R via 59R. The planetary gears 54L and 54R mesh with the sun gear 51 and the gear portions 53a of the internal gears 53L and 53R, respectively. That is, the inner peripheral portions of the internal gears 53L and 53R are extended to a position where the tip ends partially overlap with the end of the sun gear shaft 50 disposed on the same axis as the axles 21L and 21R in the axial direction. A gear portion 53a is formed at the overlapping position of the lever, and planetary gears 54L and 54R mesh with the gear portion 53a and the sun gear 51 at both ends of the sun gear shaft 50, respectively. In addition, disk-shaped retaining plates 54a fixed to the axles 21L and 21R are respectively provided on the inner sides of the planetary gears 54L and 54R on the axles 21L and 21R, and the planetary gears 54L and 54R are positioned by the retaining plates 54a. Has been.

  In each of the planetary gear mechanisms 33L and 33R, worm gears 60L and 60R to which the driving force from the electric motors 35L and 35R is transmitted are respectively connected to the outer gears 75L and 75R formed on the outer peripheral side of the internal gears 53L and 53R. Meshed. That is, the outer gears 75L and 75R provided in the internal gears 53L and 53R constituting the planetary gear mechanisms 33L and 33R respectively correspond to the worm gears 60L and 60R that rotate about the worm shafts 64L and 64R. It becomes a wheel, and the rotation axis direction of the worm gears 60L and 60R is converted into a substantially right angle direction and output. The worm shafts 64L and 64R are installed in the mission case 31 in the front-rear direction with the front-rear direction of the machine body as the axial direction, and both ends thereof are rotatably supported via bearings or the like (see FIG. 8). The transmission of the driving force from the electric motors 35L and 35R will be described later.

  In the planetary gear mechanisms 33L and 33R configured as described above, the axle is supported directly below the internal gear, so that the radial load from the internal gears 53L and 53R (in the axial direction of the axles 21L and 21R). (The load applied in the vertical direction) is applied to the inner ends 40 of the axles 21L and 21R that are spline-fitted with the carriers 52L and 52R, and the carriers 52L and 52R are tilted on the axles 21L and 21R. No inclination of the null gears 53L and 53R occurs. Thereby, the good meshing state of the gears in the planetary gear mechanisms 33L and 33R can be maintained, and the occurrence of gear wear and gear squealing can be suppressed and the life of the gear can be improved.

  Further, since the carriers 52L and 52R are supported on the axles 21L and 21R by spline fitting so that they cannot be rotated relative to each other, they are aligned by the planetary gears 54L and 54R that are rotatably supported by the carriers 52L and 52R. The action of adjusting the axis) will work. Also from this fact, it is possible to maintain a good meshing state between the gears in the planetary gear mechanisms 33L and 33R.

  Next, the support configuration of the sun gear shaft 50 and the arrangement configuration of the center sprocket 44 will be described with reference to FIG. The sun gear shaft 50 is pivotally supported on the carriers 52L and 52R via bearings.

  In the transmission 30 having such a configuration, transmission of driving force from the engine 15 will be described. As described above, the driving force from the engine 15 is transmitted to the driving force transmission shaft 28a via the engine pulley 43a provided on the output shaft 15a. The driving force transmission shaft 28a extends rearward and is connected to an input shaft 41a of the hydraulic pump 41 of the HST 32 protruding forward from the transmission case 31 via a joint. A driving force is transmitted to the input shaft 41a.

  The driving force input to the HST 32 via the input shaft 41a is shifted by the HST 32 and transmitted to the output shaft 42a. A bevel gear 49 is fixed to the tip of the output shaft 42 a and meshes with a bevel gear 62 disposed on the right side of the power transmission shaft 61 in front view. A transmission sprocket 63 is fixed in the middle of the transmission shaft 61, and a center sprocket 44 is supported on the sun gear shaft 50 so as not to rotate by spline fitting. The center sprocket 44 and the transmission sprocket are also supported. A chain 80 which is an endless chain is wound around 63. A parking brake 81 for braking the rotation of the transmission shaft 61 is attached to the left end of the transmission shaft 61.

  In such a configuration, the driving force from the engine 15 is transmitted to the HST 32 via the input shaft 41a. The driving force transmitted to the HST 32 is shifted by the HST 32, and then differentially passes through the output shaft 42a → bevel gears 49, 62 → power transmission shaft 61 → transmission sprocket 63 → chain 80 → center sprocket 44 → sun gear shaft 50. This is transmitted to the sun gears 51 of the left and right planetary gear mechanisms 33L and 33R of the mechanism 34.

  The driving force transmitted to the left planetary gear mechanism 33L is transmitted to the driving sprocket 18 of the crawler type traveling device 4L via the sun gear shaft 50 → the sun gear 51 → the planetary gear 54L → the rotating shaft 59L → the carrier 52L → the axle 21L. On the other hand, the driving force transmitted to the right planetary gear mechanism 33R is transmitted to the driving sprocket 18 of the crawler type traveling device 4R via the sun gear shaft 50 → the sun gear 51 → the planetary gear 54R → the rotating shaft 59R → the carrier 52R → the axle 21R. The In this way, the driving force from the engine 15 is transmitted to the pair of left and right axles 21L and 21R, and the left and right crawler type traveling devices 4L and 4R are rotationally driven.

  Next, the motor 35 provided in the transmission 30 will be described. As described above, in the present embodiment, the motor 35 provided in the transmission 30 is a pair of left and right electric motors 35L and 35R, and these electric motors 35L and 35R transmit driving force to the transmission 30. The rotation axis of the motor shaft is attached to the mounting surface formed on the front surface of the case elements 31L and 31R of the transmission case 31 so that the rotation axis of the motor shaft is perpendicular to the rotation axis of the axles 21L and 21R.

  The drive source may be a hydraulic motor in addition to the electric motors 35L and 35R shown in the present embodiment. In this case, a single hydraulic pump that supplies pressure oil to the hydraulic motor is linked and linked to the engine, and a variable flow rate adjusting valve that bisects the amount of pressure oil discharged from the hydraulic pump is provided. The amount of oil supplied to each hydraulic motor is changed according to the operation amount. Alternatively, a pair of variable displacement hydraulic pumps corresponding to the respective hydraulic motors may be provided, and the discharge amount of each hydraulic pump may be changed according to the operation amount of the turning lever 24.

  That is, the driving force from the pair of electric motors 35L and 35R is transmitted through the worm gears 60L and 60R meshing with the outer gears 75L and 75R as the worm wheels provided in the planetary gear mechanisms 33L and 33R, so that the electric motors 35L and 35R are driven. Is transmitted to the axle 21L or 21R of the crawler type traveling device 4L or 4R on the side corresponding to the planetary gear mechanism 33L or 33R via the planetary gear mechanism 33L or 33R on the side corresponding to.

Hereinafter, transmission of driving force from the electric motors 35L and 35R will be described with reference to FIGS. As described above, the driving force from the electric motors 35L and 35R is transmitted to the left and right planetary gear mechanisms 33L and 33R of the differential mechanism 34 via the worm gears 60L and 60R meshing with the outer gears 75L and 75R as worm wheels. However, at this time, the reduction gears 65L and 65R are interposed between the motor shafts 45L and 45R of the electric motors 35L and 35R and the worm shafts 64L and 64R of the worm gears 60L and 60R, respectively. The driving force of 35R is transmitted to the worm gears 60L and 60R via the reduction gears 65L and 65R.
As means for operatively connecting the motor shafts 45L, 45R to the planetary gear mechanisms 33L, 33R, a bevel gear, a face gear, a hypoid gear, or the like may be used in addition to the worm gear shown in the present embodiment.

Specifically, as shown in FIG. 8, recesses 90L and 90R are formed in a portion of the transmission case 31 that is in contact with the motor case 66 that accommodates the output shafts of the motors 35L and 35R. The case 31 can be accommodated.
That is, by using one surface of the motor case 66 that houses the output shafts of the motors 35L and 35R also as a lid portion of the gear case, the gear case can be provided integrally with the transmission case. In this case, the reduction gears 65L and 65R are configured to be smaller than the outer dimensions of the motor.
As described above, the gear case that accommodates the reduction gears 65 </ b> L and 65 </ b> R that has been provided individually is configured as a part of the transmission case 31.

  By comprising in this way, it becomes possible to hold down cost by suppressing the increase in the number of parts at the time of providing a gear case separately. Also, the weight of the entire work vehicle can be reduced.

  Moreover, as shown in FIG. 9, it is also possible to make it the structure which accommodates the reduction gears 65L and 65R in the motor cases 66L and 66R. That is, the reduction gears 65L and 65R can be accommodated in the motor cases 66L and 66R by extending the cylindrical portions of the motor cases 66L and 66R that accommodate the motor shafts 45L and 45R. In this case, the cost can be reduced by suppressing the increase in the number of parts as in the configuration shown above. Also, the weight of the entire vehicle can be reduced.

  The reduction gears 65L and 65R are output gears 67L and 67R fixed to the motor shafts 45L and 45R, respectively, and input gears 68L fixed to the worm shafts 64L and 64R that mesh with the output gears 67L and 67R, respectively. -It is comprised by 68R. That is, as shown in FIG. 8, the motor shafts 45L and 45R of the electric motors 35L and 35R are inserted rearwardly into the recesses 90L and 90R of the transmission case 31, and the worm shafts 64L and 64R of the worm gears 60L and 60R are the transmission case. It extends from the inside 31 toward the front and is inserted into the recesses 90 </ b> L and 90 </ b> R of the mission case 31. The output gears 67L and 67R fixed to the motor shafts 45L and 45R and the worm shafts 64L and 64R mesh with the input gears 68L and 68R in the recesses 90L and 90R of the transmission case 31, respectively. 65R is configured. In the present embodiment, the reduction gears 65L and 65R have a one-stage reduction configuration with the output gears 67L and 67R of the motor shafts 45L and 45R and the input gears 68L and 68R of the worm shafts 64L and 64R. Another gear supported by the recesses 90L and 90R of the mission case 31 may be interposed between the gears 67L and 67R and the input gears 68L and 68R to reduce the speed to a plurality of stages.

  In such a configuration, the driving force from the electric motor 35L disposed on the left side is as follows: motor shaft 45L → output gear 67L → input gear 68L → worm shaft 64L → worm gear 60L → outer gear 75L → internal gear 53L → planetary gear 54L. It is transmitted to the drive sprocket 18 of the left crawler type traveling device 4L via the rotary shaft 59L → the carrier 52L → the axle 21L. On the other hand, the driving force from the electric motor 35R arranged on the right side is as follows: motor shaft 45R → output gear 67R → input gear 68R → worm shaft 64R → worm gear 60R → outer gear 75R → internal gear 53R → planetary gear 54R → rotating shaft 59R. → The carrier 52R is transmitted to the drive sprocket 18 of the crawler type traveling device 4R on the right side via the axle 21R.

  In this way, the driving force from the left and right electric motors 35L and 35R is transmitted to the corresponding axles 21L and 21R, and the left and right crawler type traveling devices 4L and 4R are rotationally driven. The traveling speeds of the corresponding crawler type traveling devices 4L and 4R change smoothly according to the rotational speeds of the left electric motor 35L and the right electric motor 35R, and the traveling speeds between the left and right crawler type traveling devices 4L and 4R. Due to the difference, the snowplow 1 can turn smoothly.

  In this way, by interposing the reduction gears 65L and 65R between the motor shafts 45L and 45R of the electric motors 35L and 35R and the worm shafts 64L and 64R, between the motor shafts 45L and 45R and the worm shafts 64L and 64R. Therefore, the torque transmitted from the motor shafts 45L and 45R to the worm shafts 64L and 64R increases. That is, the required torque can be obtained even if the electric motors 35L and 35R are small motors. By reducing the size of the electric motors 35L and 35R in this manner, the snowplow 1 can be reduced in weight and space.

The side view which showed the whole structure of the snow remover which concerns on one Example of this invention. The schematic diagram which shows the driving force transmission path | route of a snowblower. The side view of a transmission. The front view of a transmission. The top view of a transmission. The back surface partial sectional view which shows the internal structure of a transmission. The side surface partial sectional view which shows the internal structure of a transmission. The plane partial sectional view which shows the internal structure of a transmission. The plane partial sectional view which shows the internal structure of a transmission.

Explanation of symbols

1 Snow Plow 15 Engine 21L / 21R Axle 30 Transmission 31 Transmission Case 33L / 33R Planetary Gear Mechanism 34 Differential Mechanism 35L / 35R Electric Motor 60L / 60R Worm Gear 64L / 64R Worm Shaft 65L / 65R Reduction Gear

Claims (1)

A pair of drive sources attached to the transmission case, and a differential mechanism having a pair of left and right planetary gear mechanisms configured in the transmission case, and driving power from the engine via the differential mechanism. The planetary gear mechanism through the planetary gear mechanism on the side corresponding to the drive source by transmitting the driving force from each of the drive sources to the axle of the planetary gear through a reduction element provided in the planetary gear mechanism. The transmission of the work vehicle that transmits to the axle on the side corresponding to the above-mentioned structure, wherein an internal gear that constitutes a planetary gear mechanism is arranged in the vertical direction of the inner end portion of the axle. .

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