JP2002243017A - Hydromechanical transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transmit torque of an engine to the wheel side even in an emergency when a hydrostatic transmission(HST) 24 becomes a racing rotation state of transmitting little motive power in a hydromechanical transmission(HMT) T for dividing once the torque inputted to an input shaft 25 from the engine 13 side, respectively transmitting the torque by a mechanical transmission(MT) 23 and the 24, synthesizing the torque again, and outputting the torque to the wheel (12), (16) side from an output shaft 26. SOLUTION: An HST housing part 40b of a casing body 40 is provided with a hole part 101 penetrating through a wall part of the HST housing part 40b in a part opposed to an outer peripheral surface of a cylinder barrel 56 of a motor 31 of the HST 24. A female screw is threaded on the inner periphery of this hole part 101. A lock bolt 102 is screwed in there from the outside of the casing body 40. In an emergency when the HST 24 becomes the racing rotation state, the lock bolt 102 is screwed in so that the cylinder barrel 56 of the hydraulic motor 31 is forcedly made nonrotatable.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrostatic transmission (Hydro-Stat) comprising a variable displacement piston pump / motor.
The present invention relates to a hydraulic mechanical transmission that combines a mechanical transmission (hereinafter referred to as MT) with a mechanical transmission (hereinafter referred to as HST).

[0002]

2. Description of the Related Art Conventionally, as an ATV transmission such as a four-wheel buggy, a transmission having a continuously variable transmission with a belt transmission mechanism has been widely used. The machine requires frequent maintenance, especially under severe operating conditions.
It has been proposed to replace it with the like.

For example, Japanese Patent Application Laid-Open No. Hei 7-113454 discloses a motorcycle in which a hydraulic-mechanical transmission (HMT) combining MT and HST is applied to a motorcycle. . In this apparatus, a swash plate type piston pump and a piston motor constituting an HST are arranged on the same axis so as to face each other, and a cylinder barrel of the pump and the motor is integrated with an output shaft at a central portion, so that the entire HMT is formed into a cylindrical shape. It is housed in a shape and can be laid out like a gear train.

[0004]

By the way, generally, H
In the case of a hydraulic transmission such as ST or HMT, if the leakage of hydraulic fluid increases due to, for example, breakage of a seal or the like, the power transmission may become idle, in which power cannot be transmitted, and the vehicle cannot run on its own. From, for example, AT
In the case of V, there is a risk of getting stuck in an unpopular swamp, or in the case of an agricultural vehicle such as a tractor, in the middle of a farm or the like.

[0005] The present invention has been made in view of such a point, and it is an object of the present invention that the HMT uses the power of the MT.
And HST, and is to transmit the rotational force of the engine to the wheel side even in an emergency when the HST is idle.

[0006]

According to the present invention, there is provided a mechanical transmission (MT) having a planetary gear mechanism and a hydrostatic transmission (HST) comprising a hydraulic pump / motor. In a hydraulic mechanical transmission (HMT) provided with the above, in an emergency, the driving force can be transmitted only by the MT by forcibly disabling the shaft of the hydraulic motor of the HST.

Specifically, according to the invention of claim 1, the input shaft (2
5), output shaft (26), and hydraulic pump that constitutes a closed circuit (32)
(30) and a hydraulic motor (31) and the pump (30)
And a hydrostatic transmission (24) in which at least one of the motor and the motor (31) has a variable capacity; and a first and a second input member (3
4), (36) and differential gear mechanism having one output member (37)
(28) and a mechanical transmission (23) provided with the input shaft (2
The transmission line from (5) is branched into two, one of which is connected to the hydraulic pump (30), and the other is connected to the differential gear mechanism (2).
8) connected to the second input member (36), and
(30) is connected to the first input member (34) of the differential gear mechanism (28), and the output member (37) of the differential gear mechanism (28) is connected to the output shaft (2).
Assuming a hydraulic mechanical transmission (T) connected to (6), in this configuration, a motor rotation prevention mechanism (100) for forcibly disabling the hydraulic motor (31) is provided. .

With the above configuration, during normal operation, the rotational force input to the input shaft (25) is once divided into two, one of which is driven by the HST (24) and the other is driven by the MT (23).
, And are combined in the differential gear mechanism (28) and output from the output shaft (26). On this occasion,
When the capacity of the pump (30) or the motor (31) of the HST (24) is changed, the rotation speed of the hydraulic motor (31) changes, thereby changing the speed ratio of the HMT (T). Will be.

On the other hand, when the working fluid leaks from the HST (24) due to, for example, breakage of a seal or the like, and the idle state occurs in which power cannot be substantially transmitted, the hydraulic motor (31) is driven by the motor rotation preventing mechanism (100). ) Is forcibly disabled to rotate, the first input member (34) connected to the motor (31) does not rotate, and the differential gear mechanism (28)
Only the input rotation from the input member (36) is transmitted from the output member (37) to the output shaft (26).

In other words, even in an emergency where the HST (24) is damaged in the HMT (T), the driving force can be transmitted only by the MT (23). For example, when the HMT (T) is mounted on a vehicle, This makes it possible to prevent the vehicle from running on its own.

According to the second aspect of the present invention, the motor rotation preventing mechanism is provided.
(100) is composed of a lock bolt (102) arranged so that the motor shaft (33) of the hydraulic motor (31) or the cylinder barrel (56) can be fixed to the casings (40) and (41). And
In this way, in an emergency, the motor shaft (33) or the cylinder barrel (56) is fixed to the casing (4) by the lock bolt (102).
0) and (41), the operation and effect of the first aspect of the invention can be obtained with a very simple configuration.

According to the third aspect of the present invention, the motor rotation preventing mechanism is provided.
A clutch mechanism (100) locks the motor shaft (33) of the hydraulic motor (31) or the shaft of the first input member (34) of the differential gear mechanism (28) so as not to rotate. Thereby, in an emergency, the motor shaft (33) of the hydraulic motor (31) or the shaft of the first input member (34) of the differential gear mechanism (28) can be locked by the clutch mechanism so that it cannot rotate. Thereby, the operation and effect of the invention of claim 1 can be more reliably obtained.

[0013]

(Embodiment 1) Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, a hydraulic mechanical transmission (HMT) (T) according to the present invention is mounted on a four-wheel drive ATV (A). FIG. 1 shows this A
The appearance of the TV (A) is shown, and reference numeral (1) denotes a vehicle body composed of a pipe frame (details are omitted).
Front cowl (3) with (2), (2), handle
(4), fuel tank (5), seat (6), and left and right fenders
A rear cowl (8) provided with (7) and (7) is provided.

An under cowl (10) is provided integrally with the bumper (9) below the front cowl (3) at the frontmost portion of the vehicle body. (12) and (12) are provided. Further, a power train including an engine (13), an HMT (T) and an auxiliary transmission (14) is provided from below the fuel tank (5) to below the seat (6). T) is located substantially directly below the seat (6). Rear wheels (16), (16) are disposed on the left and right sides of the vehicle body (1) via trailing arm suspensions (not shown) behind the power train.

FIG. 2 schematically shows the configuration of the power transmission system from the engine (13) of the ATV (A) to the wheels (12) and (16) when viewed from above the vehicle body. (13)
The crankshaft (13a) is mounted horizontally in the vehicle width direction of the ATV (A). On the right side (one side in the vehicle width direction) of the engine (13), an HMT (T) is disposed in contact with the crankcase, and the rear end of the HMT (T) is closer than the rear end of the crankcase of the engine (13). Also extends to the rear of the vehicle body, and on the left side (the other side in the vehicle width direction), that is, on the rear side of the vehicle body of the engine (13), the direction of the output rotation from the auxiliary transmission (14) A pair of bevel gears (17) and (17) for changing are arranged. The driven side bevel gear (17) is provided on a drive shaft (18) extending in the vehicle longitudinal direction below the vehicle body (1).
8) Both front and rear ends of the differential gear (1
The front wheel axle (20) and the rear wheel axle (21) are connected via 9) and (19). In other words, the HMT (T) is provided on the right side of the center of the engine (13) in the vehicle width direction, and is located outward in the vehicle width direction in the power train.

The HMT (T) divides the input rotation from the crankshaft (13a) of the engine (13) into two parts, and separates the input rotation into a mechanical transmission (MT) (23) and a hydrostatic transmission, respectively. (H
ST) (24), and is synthesized and output by the planetary gear mechanism of the MT (23). That is,
As shown in FIGS. 3 and 4, the MT (23) is:
An input shaft (25) directly connected to the end of a crankshaft (13a) protruding to the right side of the vehicle body of the engine (13), and an input gear (27) rotatably provided by a spline at an intermediate portion of the input shaft (25).
A planetary gear mechanism (28) which is arranged on the same axis as the output shaft (26) and receives input rotation from the input gear (27).
(Differential gear mechanism). The HST (24)
The swash plate type axial piston pump (30) (hereinafter simply referred to as piston pump) and the swash plate type axial piston motor (31) (hereinafter simply referred to as motor) are connected by a closed circuit (32).

The planetary gear mechanism (28) of the MT (23) includes a sun gear (34) rotatably provided integrally with a shaft (33) of a motor (31).
(A first input member) and a plurality of planetary gears that mesh with the sun gear (34) and revolve while rotating around the sun gear (34).
(35) (only one is shown in the figure), and a ring gear in which the inner teeth of the inner periphery mesh with the plurality of planetary gears (35), and the outer teeth of which are formed with the outer teeth meshing with the input gear (27). (36)
(A second input gear) and a planetary carrier (37) (output member) that is rotatably provided at one end of the output shaft (26) and rotatably supports the plurality of planetary gears (35). Consists of

A part of the torque input to the input shaft (25) is transmitted from the input gear (27) to the planetary gear mechanism (28).
To the ring gear (36), while the remaining rotational force is converted to hydraulic pressure by the piston pump (30),
(32) to the motor (31), which is again converted to rotational force by the motor (31) and
(34). Then, the rotating forces transmitted from the rotating ring gear (36) and the sun gear (34) to the plurality of planetary gears (35) meshing with them are combined,
The output is output from the planetary carrier (37) to the output shaft (26).

Hereinafter, the configuration of the HMT (T) of this embodiment will be described in more detail. First, as shown in FIG. 3, the MT (23) and the HST (24) are integrally provided in one casing. That is, the casing body (40) of the HMT (T) is divided into one side (the right side of the vehicle body) and the other side (the left side of the vehicle body) in the axial direction of the input shaft (25),
A portion on the right side of the vehicle body with respect to the partition wall portion (40a) has its open end closed by an end cap (41), and the HST (2
The HST accommodating portion (40b) accommodating the piston pump (30) and the motor (31) of 4) together. Further, a portion of the casing body (40) on the left side of the vehicle body with respect to the partition wall portion (40a) is closed by a cover member (42).
The MT accommodation section (40c) that accommodates the T (23).

In the case of this embodiment, the input shaft of HMT (T)
(25) is formed integrally with the pump shaft of the piston pump (30), and the integrated input shaft (25) is connected to the casing body (40).
On the front side of the vehicle body (upper side in the figure), the cover (42) is disposed so as to extend from the cover (42) to the partition (40a) and the end cap (41) in the vehicle width direction. It is rotatably supported by rolling bearings (45), (46), (47) disposed on the part (40a) and the end cap (41), respectively. In other words, the input shaft (25) has a function of the original input shaft portion (25a) that receives rotation from the crankshaft (13a) and a function of a pump shaft at a portion indicated by a virtual line C in the drawing. The pump shaft (25b) is integrated with the pump shaft (25b). Incidentally, the input shaft (25) and the pump shaft may be separately formed, and they may be coupled by coupling or the like.

On the other hand, the output shaft (26) of the HMT (T) is arranged on the rear side (lower side in the figure) of the casing body (40) so as to extend in the vehicle width direction in parallel with the input shaft (25). In the cylindrical boss (42a) formed so as to protrude outward (left side in the figure) of the cover member (42), two bosses (42a) provided on the boss (42a) are provided. Rolling bearings (48), (48)
It is rotatably supported by. That is, the input shaft
(25) and the output shaft (26) are connected to the crankshaft (13
a) and optionally extending parallel to the vehicle width direction, they are disposed in parallel spaced in the vehicle longitudinal direction. Also, the output shaft (26)
Is located on the same axis as the shaft (33) of the motor (31), and its left end (the other side in the vehicle width direction) is connected to the main shaft of the auxiliary transmission (14) by a coupling (not shown). On the other hand, the right end (one side in the vehicle width direction) of the vehicle body is connected to a planetary carrier (37) of the planetary gear mechanism (28).

That is, the motor shaft (33) of the HST (24)
The partition wall (40a) and the end cap (41) extend in the vehicle width direction through the partition wall (40a) of the casing body (40).
Are rotatably supported by rolling bearings (49) and (50) disposed respectively. The ring gear (36) of the planetary gear mechanism (28) is arranged on the motor shaft (33) penetrating through the partition (40a) and protruding into the MT accommodating portion (40c) in order from the partition (40a). ), Sun gear (34) and planetary carrier (3
7) is provided. The ring gear (36) is a motor shaft
(33) A disk-shaped plate part (36a) rotatably arranged on bearings (51) and (51), and an annular gear part (36b) mounted on a surface near the outer periphery of this plate part Consisting of
Internal teeth that mesh with the planetary gear (35) from the outside are formed on the inner peripheral side of the gear portion (36b), and external teeth are formed on the outer peripheral side so as to mesh with the input gear (27).

The sun gear (34) has a motor shaft (33).
And a planetary gear (35) that is rotatably connected to the ring gear (36) by a spline.
It is adapted to engage from the inside to the. Further, the planetary carrier (37) is externally inserted into the end of the output shaft (26), and is fixed to the cylindrical portion (3
Has 7a), have relatively enlarged diameter portion of the large-diameter (37b) and a disk-shaped flange portion and (37c) is provided on one side of the cylindrical portion (37a), the enlarged diameter portion ( The motor shaft (33) is rotatably attached to the other end of the motor shaft (33) in the vehicle width direction by a rolling bearing (52) press-fitted into the inside of the 37b). The collar of this planetary carrier (37)
The (37c), each of a plurality of locations spaced at equal intervals in the circumferential direction pin (53), (53), ... are (only one shown in the figure) is arranged, the pins (53 Rolling bearing (5)
In 4), a planetary gear (35) is rotatably supported.

In short, the planetary gear mechanism (28) of the MT (23)
Is located on the right side of the vehicle body of the output shaft (26) and connected to the end of the output shaft (26) on the right side of the vehicle body, while being located on the right side of the vehicle body with the partition wall (40a) of the casing body (40) interposed therebetween. The motor (31) is also connected to the shaft (33). The motor shaft (33) is divided into a center axis of the planetary gear mechanism (28) and an original motor shaft (33) with a portion indicated by a virtual line C 'in the drawing as a boundary, and these two shafts are separated. May be bonded at the site by coupling or the like.

Subsequently, the piston pump (30) of the HST (24)
The structure will be described in more detail. The piston pump (30) has a cylinder barrel (56) integrally provided on a pump shaft portion (25b) of an input shaft (25), and details thereof are not shown, but the inside of the cylinder barrel (56) is not shown. , A plurality of cylinder chambers (57), (57),... Extending in the direction of the axis (X) at predetermined intervals in the circumferential direction at positions on the circumference centered on the axis (X).
Is provided. A port (58) is individually formed on one axial side (right side in the figure) of each of the cylinder chambers (57) so as to open to an end face on one axial side of the cylinder barrel (56). The other side of each cylinder chamber (57) is open at the other end in the axial direction of the cylinder barrel (56).
9) is reciprocally accommodated.

A variable swash plate (60) for adjusting the reciprocating stroke of the pistons (59), (59),... Is disposed facing the other end face of the cylinder barrel (56). . The swash plate (60) has a piston (5) projecting from the cylinder chamber (57).
A thrust plate (61) for holding the end of (9) in abutting state is supported by two rolling bearings (62) and (63), and the axial center together with the piston (59) and the cylinder barrel (56). It can rotate smoothly around X). Further, the variable swash plate (60) sandwiches a neutral position where the swash plate angle becomes zero,
As shown in FIG. 3, the swash plate is configured to be tiltable between the maximum tilt positions on both the normal rotation side and the reverse rotation side where the swash plate angle is maximum. Thus, the inclination angle is increased or decreased.

When the input shaft (25) and the cylinder barrel (56) are rotationally driven by the input from the engine (13), the pistons (59), (59),. While revolving around the swash plate, the stroke corresponding to the inclination angle of the variable swash plate (60) reciprocates, whereby each cylinder chamber (57)
Supply and discharge of hydraulic oil to and from the vehicle will be performed. That is, in the cylinder chamber (57) in the hydraulic oil discharge stroke, the piston (59) is pushed into the cylinder chamber (57) along the inclination of the swash plate (60), whereby the cylinder chamber (57) Hydraulic fluid is port
It is discharged from the cylinder barrel (56) via (58). On the other hand, in the cylinder chamber (57) in the suction stroke, the piston (59)
Receives the pressure (charge pressure) of the hydraulic oil flowing into the cylinder chamber (57) through the port (58), and is gradually pushed out of the cylinder chamber (57) along the inclination of the swash plate (60).

The supply and discharge of the hydraulic oil to and from each of the cylinder chambers (57) is performed via a valve plate (65) that is in sliding contact with the port-side end surface of the cylinder barrel (56). That is, the valve plate (65) is a closed circuit (32) between the pair of oil passages (66), (66) formed in the end cap (41), that is, the piston pump (30) and the motor (31). ) Is configured to switch the communication state of the cylinder chambers (57), (57),... With respect to a pair of oil passages which constitutes a pair of oil passages. The cylinder barrel (56) is provided with two arc-shaped cross-section holes (68) and (68) which are respectively long in the circumferential direction and correspond to (66). Then, as described above, the cylinder chambers (57), (5)
The hydraulic oil discharged from 7), ... flows through one hole (68) of the valve plate (65) to one oil passage (66), while returning from the other oil passage (66). The oil is supplied to the cylinder chambers (57), (57),
...

The valve plate (65) is of a floating type which is urged against a port side end surface of the cylinder barrel (56) by a coil spring (69). That is, the valve plate (65) is a cylinder barrel.
(56) a relatively large-diameter large cylinder member (65a) having a sliding contact surface that slides on the end face on the port side, and a small cylinder member (65b) fitted inside the large cylinder member; The small cylinder member (65b) is press-fitted into an annular groove provided in the end cap (41) and fixed, and the large cylinder member (65a) is attached to the small cylinder member (65b) in a loose fit state. The coil spring
It is pressed against the port side end surface of the cylinder barrel (56) by (69).

As described above, by making the large cylindrical member (65a) that is in sliding contact with the cylinder barrel (56) a floating type, the dimensional error of the cylinder barrel (56) and the end cap (41) is absorbed, and The slidable contact state between the port-side end surface of the cylinder barrel (56) and the valve plate (65) can be favorably maintained. Although not shown, the large cylindrical member (6
An O-ring or the like is provided between 5a) and the small cylinder member (65b) so that the leakage of hydraulic oil between the two members can be maintained at a predetermined amount or less.

Further, the tip of the input shaft (25) penetrates a hole formed in the end cap (41), and the end of the input shaft (25) has a leak in the closed circuit (32) of the HST (24). A charge pump (70) for replenishing oil is provided. The charge pump (70) is, for example, a trochoid pump. As shown in FIG. 4, the charge pump (70) pumps hydraulic oil from an oil sump (71) independent of an oil pan of the engine (13) to form a closed circuit (32). ) Is supplied to the lower pressure side of the pair of oil passages (66), (66) via check valves (72), (72). At this time, the pressure of the hydraulic oil supplied to the low-pressure side oil passage (66) is
, The value of which is set by the bleed-off valve (73).

The closed circuit (32) has a pair of oil passages.
When the pressure state of the hydraulic oil on the high pressure side of (66) and (66) becomes higher than a predetermined value, the oil passage on the high pressure side (66)
A pair of relief valves (74) and (74) are disposed so as to allow the operating oil pressure to escape to the low-pressure side oil passage (66), and separately from this pair of oil passages (74) under predetermined conditions. A bypass valve (75) composed of an electromagnetic valve for shutting off the power transmission in the HST (24) is provided so as to connect the (66) and (66) with each other. This bypass valve (75) is normally connected to the pair of oil passages (6
6), (66) closed position that does not communicate with each other (position shown in the figure)
On the other hand, in response to a control signal from a controller (not shown), the oil passages (66) and (66) are switched to a communication position for communicating with each other.
(T) has a clutch function of switching to a power cutoff state in which power is not transmitted.

While the input-side piston pump (30) of the HST (24) is configured as described above, the output-side motor (31) also has a fixed inclination angle of the swash plate (76). The motor (31) has substantially the same configuration except for that described above, and therefore, the same members as those of the piston pump (30) are denoted by the same reference numerals in the motor (31), and detailed description thereof will be omitted. As described above, the piston pump (30) and the motor (31) are housed in the HST housing part (40b) of the HMT (T) casing body (40).
Are not filled with hydraulic oil, but instead, nozzles (80), (80),... For injecting hydraulic oil are provided as shown by phantom lines in FIG.

The nozzles (80), (80),... May be provided so as to open toward the inside of the HST accommodating portion (40b) on the inner wall of the end cap (41), for example, as shown in the figure.
Alternatively, it may be provided on the casing body (40). This nozzle
Hydraulic oil is supplied to the (80) from the charge pump (70), and spray oil is ejected.
Cylinder barrel of piston pump (30) and motor (31) (5
The rotational resistance of 6) can be greatly reduced, and spray-type hydraulic oil can be supplied to the sliding portion to appropriately perform lubrication and cooling. Although not shown,
A drain passage for discharging hydraulic oil is provided at the bottom of the HST accommodating portion (40b).

Next, the characteristic portion of the present invention will be described. In the HMT (T) of this embodiment, the leakage of hydraulic oil increases due to, for example, breakage of a seal or the like, and the HST (24) can hardly transmit power. An emergency mechanism is provided to enable the power of the engine (13) to be transmitted to the wheels (12) and (16) only by the MT (23) when the vehicle is idle. That is, as shown in FIG.
The ST barrel (40b) has a cylinder barrel (5
6) at a position facing the outer peripheral surface of the HST accommodation portion (40).
A hole (101) penetrating the wall of (b) is provided, and this hole (10
Female screw is threaded on the inner circumference of 1), and the casing body
A lock bolt (102) is screwed in from outside (40).

When the lock bolt (102) is completely screwed into the hole (101), its tip abuts on the outer peripheral surface of the cylinder barrel (56) of the motor (31) to prevent its rotation. In a normal state, the tip is located near the outer peripheral surface of the cylinder barrel (56) and is screwed halfway into the hole (101) so as not to contact the surface. It has been. With this hole (101) and lock bolt (102),
A motor rotation preventing mechanism (100) for forcibly disabling the hydraulic motor (31) is provided.

Next, the operation of the HMT (T) according to the present embodiment will be described.
The input shaft (25) is rotated by the operation of the engine (13) of (A), and a part of this rotational force is transmitted through the MT (23), that is, the input shaft (25).
The transmission is transmitted from the input gear (27) on the (25) to the ring gear (36) of the planetary gear mechanism (28), and the cylinder barrel (56) of the piston pump (30) is rotated. This cylinder barrel
By the rotation of (56), the pistons (59), (59),... Reciprocate along the variable swash plate (60) in the inclined state, whereby the piston pump (30) and the motor (31) are moved. The supply of the hydraulic oil in the step (1) transmits a part of the torque transmitted to the input shaft (25) to the motor (31).

That is, the cylinder barrel (56) of the motor (31) is rotated by receiving the hydraulic oil supplied by the closed circuit (32), and the motor shaft (33) integrated with the cylinder barrel (56) is rotated.
There it is rotated, the rotational force is transmitted to the sun gear (34) on the motor shaft (33). Thus, as described above, the rotational force transmitted from the input gear (27) to the ring gear (36) and HS
The rotational force transmitted to the sun gear (34) via the T (24) is combined through a plurality of planetary gears (35) and output from the planetary carrier (37) to the output shaft (26). At this time, by changing the inclination angle of the variable swash plate (60) of the piston pump (30), the rotation speed of the hydraulic motor (31) is changed, whereby the speed ratio of the HMT (T) is reduced. Changed to a stage.

The rotation of the output shaft (26) is controlled by the auxiliary transmission (1).
4), via the drive shaft (18) and the axles (20), (21), etc., to the four wheels (12), (16),.

On the other hand, for example, HS
When the operating oil leaks at T (24) and the idle state where power can hardly be transmitted, the lock bolt (1
02) may be screwed in to forcibly make the cylinder barrel (56) of the motor (31) unrotatable. By doing so, the sun gear (34) provided on the motor shaft (33) is fixed, so that the planetary gear mechanism is moved from the input gear (27) on the input shaft (25).
The rotational force transmitted to the ring gear (36) of (28) is transmitted from the planetary carrier (37) of the planetary gear mechanism (28) to the output shaft (26).
To the four wheels (12), (16),... Of the ATV (A).

Therefore, according to the hydraulic mechanical transmission (HMT) (T) according to the first embodiment, the motor rotation preventing mechanism (100) forcibly making the motor (31) of the HST (24) impossible to rotate. ), The driving force can be transmitted only by the MT (23) even in an emergency in which the HST (24) is damaged or the like and the leakage of the hydraulic oil increases due to the HST (24).
The ATV (A) can be prevented from running on its own, and even if a failure occurs in an unpopular swamp or the like, it can be safely returned. Moreover, in this embodiment, the motor rotation prevention mechanism (100) can be realized at a very low cost by a very simple configuration of the lock bolt (102).

(Embodiment 2) FIG. 5 shows an HMT according to Embodiment 2 of the present invention, which differs from the HMT (T) of Embodiment 1 only in the configuration of the motor rotation prevention mechanism (100). Except for this point, the configuration of the HMT (T) of the second embodiment is the same as that of the first embodiment, and therefore, the same members will be denoted by the same reference numerals and description thereof will be omitted. As shown in the figure, in the case of the second embodiment, the motor rotation prevention mechanism (100) is provided on the motor shaft (33), and is a disk-shaped plate having external teeth formed all around the outer circumference. Member (1
03) and a sleeve member (104) provided with internal teeth so as to mesh with the external teeth of the plate member (103).

The sleeve member (104) is formed in a substantially annular shape having a larger diameter than the plate member (103), and is externally attached to a boss (40d) formed on a partition (40a) of the casing body (40). It is provided so as to be able to move in the direction of the axis (X) and to be unable to rotate around the axis (X), and to engage with the plate member (103) by operating a lever member (not shown). The rotation can be switched between an engaged state and a disengaged state for preventing the rotation. That is, a lever that is drivingly connected to the sleeve member '104) via a link mechanism is provided outside the casing body (40), and the sleeve member (104) is disengaged by positioning this lever at the normal position. Maintained in the engaged state, on the other hand, by operating the lever and positioning it in the emergency travel position, the sleeve member (104) engages with the plate member (103) to prevent rotation of the motor shaft (33). Become like

Therefore, according to the second embodiment, H
When ST (24) is in the idling state where power can hardly be transmitted, by operating the lever to engage the sleeve member (104) with the plate member (103), the HST (2
The shaft (33) of the motor (31) of 4) can be reliably made in a non-rotatable state.
The output rotation of (13) is performed by the wheels (12) and (16) only by MT (23).
Can be transmitted to the side.

The present invention is not limited to the configurations of the first and second embodiments, but encompasses other various configurations. That is, in the first embodiment, as the motor rotation prevention mechanism (100), the cylinder barrel (56) is restrained by the lock bolt (102). However, the present invention is not limited to this, and the motor shaft is prevented by the lock bolt (102). (33) may be restricted.

In the second embodiment, the motor shaft (33)
The planetary gear mechanism (28) is provided on the upper side, and the motor shaft (3
However, the invention is not limited to this. For example, the motor shaft (33) and the shaft of the planetary gear mechanism (28) are divided into two parts, and the planetary gear is used as a lock clutch mechanism. The shaft of the sun gear (34) in the mechanism (28) may be directly restrained.

Further, in each of the above embodiments, the HMT (T) according to the present invention is applied to the ATV (A). However, the present invention is not limited to this. For example, agricultural vehicles such as tractors and industrial vehicles such as forklifts. Alternatively, HMT (T) can be applied to various vehicles such as golf carts.

[0048]

As described above, according to the hydraulic mechanical transmission (HMT) (T) according to the first aspect of the present invention, the MT (23) having the differential gear mechanism (28) is In an HMT (T) provided with an HST (24) comprising a pump (30) and a motor (31), a motor rotation preventing mechanism (100) forcibly disabling the hydraulic motor (30) of the HST (24). ), The leakage of the working fluid of the HST (24) increases due to, for example, breakage of the seal and the like. (31) is made unrotatable so that the driving force can be transmitted only by the MT (23). Therefore, for example, the H
When the MT (T) is mounted on the vehicle (A), the vehicle (A) can be prevented from being unable to run on its own.

According to the second aspect of the present invention, since the motor rotation preventing mechanism (100) is made of the lock bolt (102), the effect of the first aspect of the invention can be obtained with a very simple configuration.

According to the third aspect of the present invention, the motor rotation prevention mechanism (100) is a lock clutch mechanism.
The effect of the invention of (1) can be more reliably obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an external appearance of an ATV equipped with an HMT according to the present invention.

FIG. 2 is a schematic diagram showing a configuration of a power transmission path of the ATV when viewed from above the vehicle body.

FIG. 3 is a cross-sectional view illustrating a configuration of an HMT.

FIG. 4 is a skeleton diagram illustrating a configuration of an HMT.

FIG. 5 is a diagram corresponding to FIG. 3 according to the second embodiment.

[Explanation of symbols]

 (T) Hydraulic mechanical transmission (HMT) (23) Mechanical transmission (MT) (24) Hydrostatic transmission (HST) (25) Input shaft (26) Output shaft (28) Output gear (30 ) Hydraulic piston pump (31) Hydraulic piston motor (32) Closed circuit (33) Motor shaft (34) Sun gear (first input member) (36) Ring gear (second input member) (37) Planetary carrier (output member) ( 102) Lock bolt (103) Plate member (clutch mechanism) (104) Sleeve member (clutch mechanism)

Claims (3)

[Claims] An input shaft (25), an output shaft (26), and a closed circuit (3
A hydrostatic transmission (24) comprising a hydraulic pump (30) and a hydraulic motor (31) constituting at least 2) and at least one of the pump (30) and the motor (31) having a variable capacity; First and second two input members (34), (36) and one output member (3
Mechanical transmission (23) with differential gear mechanism (28) having (7)
A transmission line from the input shaft (25) is branched into two, one of which is connected to a hydraulic pump (30), and the other is a second input of a differential gear mechanism (28). The hydraulic motor (30) is connected to a member (36), and the hydraulic motor (30) is a first input member of the differential gear mechanism (28).
(34), an output member (37) of the differential gear mechanism (28) is connected to the output shaft (26) in the hydraulic mechanical transmission (T), wherein the hydraulic motor (31) 1. A hydraulic mechanical transmission, comprising: a motor rotation preventing mechanism (100) for forcibly preventing the motor from rotating. 2. The motor rotation preventing mechanism (100) according to claim 1, wherein the motor shaft (33) or the cylinder barrel (56) of the hydraulic motor (31) is connected to the casing (40), (4).
1) A hydraulic mechanical transmission, comprising a lock bolt (102) arranged to be fixable to 1). 3. The motor rotation inhibiting mechanism (100) according to claim 1, wherein the motor shaft (33) of the hydraulic motor (31) or the shaft of the first input member (34) of the differential gear mechanism (28). A hydraulic mechanical transmission, which is a clutch mechanism that locks to prevent rotation.