JPH06312627A - Hydraulic power transmission - Google Patents

Abstract

PURPOSE:To transmit power with simple structure and prevent oil leak by devising such a measure as to communicate oil pressure generating chambers with an oil tank through main and auxiliary oil passages, orifices, one-way valves, and the like. CONSTITUTION:In a power transmission 26, driven gears 31 rotatably supported by a retainer 30 are meshed with a ring gear disposed in the axially movable state on the inner surface of a casing 29 so as to form oil pressure generating chambers A-H. In such constitution, the oil pressure generating chambers A-H and an oil tank 38 are communicated with each other by main oil passages 27a, 27b through orifices 46c, 46d. The orifices 46c, 46d of the main passage 27, the oil pressure generating chambers A-H and the oil tank 38 are communicated with one another by auxiliary oil passages 50a, 50b through one-way valves 46e, 46f. Hydraulic operating chambers a, b for making oil pressure act upon movable side plates 44 are further communicated between the orifices 46e, 46f of the main oil passage 27 and the oil pressure generating chambers A-H.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic power transmission device, and more particularly, to an improved arrangement structure of an orifice, a one-way valve, etc., capable of transmitting power with a simple structure and preventing oil leakage. .

[0002]

2. Description of the Related Art Various types of power transmission devices for vehicles have been proposed in which power on the drive wheels side is transmitted to driven wheels. Among them, there is a hydraulic power transmission device using a gear pump that has a preferable relationship between the rotational speed difference between the front and rear wheels and the torque transmitted.

In this type of transmission device, as shown in FIG. 6 as a first conventional example, in a casing 1 to which a first rotating shaft (for example, a propeller shaft) is connected, a flange 2 portion is provided with a second rotating shaft. A retainer 3 to which (for example, a drive shaft) is connected is coaxially arranged, and a driven gear 4 rotatably supported by the retainer 3 is meshed with a ring gear 5 provided on the inner surface of the casing 1 to form a casing 1, a ring gear 5, The driven gear 4 and the retainer 3 form a hydraulic pressure generation chamber. Then, the ring gear 5 and the driven gear 4 pressurize the hydraulic oil in the hydraulic pressure generating chamber in accordance with the rotation difference between the propeller shaft and the drive shaft, and the hydraulic pressure transmits torque between the propeller shaft and the drive shaft. Is configured to.

By the way, in such a structure, there is a problem that the hydraulic oil in the hydraulic pressure generating chamber leaks to the outside of the hydraulic pressure generating chamber as the hydraulic pressure rises. This oil leakage mainly occupies most of the gap 6 between the axial end surface 4a of the driven gear 4 and the inner surface 1a of the casing 1.

As a measure for preventing such oil leakage, there is a method of increasing the dimensional accuracy of the width of the gear arrangement chamber of the casing 1 and the axial length of the driven gear 4 in order to make the gap 6 as narrow as possible.

However, in the method of the first conventional example, there is a limit to increase the dimensional accuracy of each component, and therefore, there is a problem that the high-pressure gear pump becomes expensive.

Therefore, the applicant of the present invention has proposed a hydraulic power transmission device capable of preventing oil leakage without increasing the dimensional accuracy of each part so much. The apparatus will be described based on the schematic system diagram showing the hydraulic oil flow path in FIG. 7. This device forms the hydraulic pressure generating chambers (A to F) similarly to the above-mentioned conventional example, and a normal oil passage 9a for communicating the respective hydraulic pressure generating chambers (A to F) with the oil tank 7 through the orifice 8. An auxiliary oil passage 9b for direct communication is provided, and six check valves 10 are provided for each hydraulic pressure generation chamber to restrict the flow direction of the working oil in each of the positive and auxiliary oil passages 9a, 9b to one direction. There is. The seal plate 11 is in sliding contact with the end face of the driven gear 4, and the seal oil pressure chamber 12 that causes the oil pressure between the orifice 8 of the normal oil passage 9a and the oil pressure generating chamber to act on the seal plate 11.

In this device, the oil pressure in the seal oil pressure chamber 12 acts on the seal plate 11 to prevent oil leakage.

[0009]

However, in the above-mentioned device proposed by the present applicant, although it is not necessary to increase the dimensional accuracy of each part so much, it is necessary to always regulate the flow direction of the hydraulic oil to the seal plate 11 side. Because of this, a total of 12 check valves 10 for forward and reverse rotation are provided for each of the six hydraulic pressure generation chambers (A to F). Therefore, the processing man-hour increases with the number of parts,
There is a problem of increased costs. Also, because of its structure, the retainer 3
Since there are restrictions on the size of the driven gear 4,
The diameter dimension is also limited, which causes a problem that affects the transmission torque. Furthermore, the same orifice 8 is used for both forward and reverse rotation.
Since it is a structure using, there is also a problem that the transmission torque cannot be changed during forward and reverse rotation.

The present invention has been made in view of the above conventional problems, and an object thereof is to provide a hydraulic power transmission device capable of transmitting power with a simple structure and preventing oil leakage.

[0011]

The invention according to claim 1 is the first
A retainer, to which a second rotary shaft is connected, is coaxially arranged in a casing to which a rotary shaft is connected, and a driven gear rotatably supported by the retainer is meshed with a ring gear provided on the inner surface of the casing, casing,
Forward and reverse hydraulic pressure generating chambers are formed by the ring gear, the driven gear and the retainer, and the hydraulic oil in the hydraulic pressure generating chamber is boosted by the ring gear and the driven gear in accordance with the rotation difference between the first and second rotary shafts. In a hydraulic power transmission device for transmitting power between a first rotary shaft and a second rotary shaft, a forward and reverse main oil passage that connects the forward and reverse oil pressure generation chambers and an oil tank through an orifice. A forward / reverse auxiliary oil passage that connects the oil tank between the orifices of the normal / reverse main oil passages and the oil pressure generation chamber, and a forward / reverse auxiliary oil passage that is provided between the oil pressure generation chamber and the oil tank. A one-way valve that blocks the flow of hydraulic oil, a movable side plate that is in sliding contact with one end surface of the driven gear in the axial direction and is movable in the axial direction, an orifice of the forward and reverse main oil passages, and a hydraulic pressure generation chamber. The hydraulic pressure above Positive to act on rotating side plates, it is characterized in that a reverse hydraulic chamber.

[0012]

According to the hydraulic power transmission device of the present invention, the working oil in the normal or reverse hydraulic pressure generating chamber is transferred to the normal or reverse main gear between the ring gear and the driven gear in accordance with the rotation difference between the first and second rotary shafts. The oil is discharged to the oil passage, is throttled by the orifice of the main oil passage, and its flow is blocked by the one-way valve of the auxiliary oil passage to increase the pressure, whereby torque is transmitted between the both rotary shafts.
At this time, the hydraulic pressure also acts on the movable side plate in the forward or reverse hydraulic pressure working chamber, whereby the movable side plate presses one end face in the axial direction of the driven gear and causes the other end face to slidably contact the inner face of the casing. Seal both ends of the driven gear.

As described above, according to the present invention, the forward and reverse hydraulic oil pressure chambers communicating with the orifices of the normal and reverse main oil passages and the hydraulic pressure generation chamber are provided, and the hydraulic pressure generated in the hydraulic pressure generation chamber is applied to the movable side plate. Since the movable side plate is pressed against the driven gear to seal both end faces of the gear, there is no need to provide a one-way valve for each hydraulic pressure generation chamber, and the hydraulic pressure is always applied to the movable side plate regardless of whether the rotation direction is normal or reverse. Can be made to act and the both end faces can be sealed.

Also, the one-way valve can reduce the number of parts required, the number of processing steps, and the necessary arrangement space by using two forward and reverse valves. Therefore, the number of driven gears can be increased and the capacity can be increased.

Furthermore, since the orifices dedicated to the forward and reverse rotations are provided, the forward and reverse transmission torques can be set arbitrarily.

[0016]

Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 5 are views for explaining a power transmission device according to an embodiment of the present invention, FIG. 1 is a schematic configuration diagram of a four-wheel drive vehicle, and FIG. 2 is a configuration diagram schematically showing hydraulic oil flow paths. 3 is a cross-sectional side view, FIG. 4 is an enlarged view of a main part of FIG. 3, and FIG.
5 is a sectional view taken along line VV of FIG. In the present embodiment, a case where the present invention is applied to a four-wheel drive vehicle based on the front engine / rear drive system will be described as an example.

In FIG. 1, reference numeral 17 denotes a four-wheel drive vehicle to which the device of this embodiment is applied.
A transmission 19 is connected to 8 via a clutch, and a transfer 20 is connected to the transmission 19. This transfer 20
Transmits the driving force from the engine 18 to the rear wheel 22 via the propeller shaft 21, and at the same time, the transmission shaft 23
Is transmitted to the front wheel 24 via the front differential 24a between the front wheel 24 and the transmission shaft 23.
A front differential (hereinafter abbreviated) is disposed, and a rear differential 25b (hereinafter rear differential) is disposed between the rear wheel 22 and the propeller shaft 21.

The front differential 25a and the transmission shaft 2
3, a hydraulic power transmission device 26 for increasing / decreasing the driving force to the front wheels 24 according to the running condition and consequently controlling the driving force distribution ratio to the front and rear wheels 24, 22 is arranged. It is set up.

The power transmission device 26 has forward and reverse main oil passages 27a and 27, as schematically shown in FIG.
It is of a gear pump type which incorporates a main oil passage 27 composed of b, an oil tank 38, and the like. This power transmission device 26
In the casing 29, a retainer 30 is rotatably and coaxially arranged, and four driven gears 31 rotatably supported by the retainer 30 are axially movable on the inner surface of the casing 29. Installed ring gear 3
2, the ring gear 32, the driven gear 3
1, a structure in which a hydraulic pressure generating chamber (A to H) is formed by the casing 29 and the retainer 30. The retainer 30 is connected to the front differential 25a, and the casing 29 is connected to the transmission shaft 23. As a result, the hydraulic oil in the hydraulic pressure generating chambers (A to H) is increased in pressure by the driven gear 31 and the ring gear 32 according to the rotation difference between the front and rear wheels 24, 22, and thus the transmission shaft 23 and the front. Power is transmitted to the differential 25a.

3 to 5 showing the concrete structure of the power transmission device 26, the casing 29 comprises a disc-shaped bottom wall portion 29a and a bottomed cylindrical body portion 29b fixed to the bottom wall portion 29a. The ring gear 32 is inserted and arranged in the body portion 29b.

The retainer 30 has a four-lobed main body 30a for rotatably supporting the driven gear 31,
And a large diameter portion 33e and a tip portion 33f of the shaft portion 33 which are spline-fitted to the rolling bearing 3
It is rotatably supported by the casing 29 via 4, 35. A pressure resistant oil seal 36 is provided between the body portion 29b of the casing 29 and the large diameter portion 33e of the shaft portion 33. Further, the tip portion 33 of the shaft portion 33
The opening 29c of the bottom wall portion 29a in which f is inserted is closed by a lid member 37 and a seal member 38.

An oil tank 38 is formed at the axial center of the large-diameter portion 33e of the shaft 33 so as to store the working oil and absorb the increase in the volume of the working oil due to the rise in the oil temperature. The oil tank 38 has a structure in which a piston 39 is slidably inserted in a cylinder hole 38a and a piston ring 40 seals between the two.

On the other hand, referring to FIG.
To the right of the driven gear 31 in the drawing, the weight 4 that moves in the radial direction by the centrifugal force generated by the rotation of the casing 29.
1 and the body portion 29 by the radial movement of the weight 41.
A cam 42 that moves in the axial direction is provided along the inner surface of b. Further, the retainer 3 is provided on the back surface of the cam 42.
The seal plate 4 slidably slidably contacts the right end surfaces of the main body 30a of 0, the driven gear 31, and the ring gear 32.
3 is arranged via a thrust bearing 43a.

Further, on the left side of the driven gear 31 in the casing 29 in the drawing, there is a male taper surface 44a having a smaller diameter on the left side of the drawing, and the main body portion 30 of the retainer 30.
A movable side plate 44 slidably slidably provided on the left end surfaces of the a, the driven gear 31, and the ring gear 32.
The male taper surface 44a of the movable side plate 44 is fitted to the female taper surface 47a of the guide member 47 fixed to the inner surface of the casing 29. Further, two large and small piston holes 44b and 44c are formed in parallel in the axial direction in the movable side plate 44, and the piston 4 is formed in the piston holes 44b and 44c.
The large-diameter piston portion 46a and the small-diameter piston portion 46b of 6 are inserted. The space surrounded by the large-diameter piston hole 44b, the bottom surface of the large-diameter piston portion 46a, and the tip surface is one hydraulic working chamber a, and is surrounded by the small-diameter piston hole 44c and the bottom surface and the tip surface of the small-diameter piston portion 46b. The separated space is the other hydraulic working chamber b. The piston 46 is mounted on the rear surface of the body 2 via a thrust bearing 48 disposed on the back surface.
It is supported by the bottom surface of 9b. Also, this piston 46
Is a pin 45 together with the movable side plate 44 and the retainer 30.
It is locked to the main body portion 30a and rotates together with the main body portion 30a.

As shown in FIG. 4, the piston 46 has an orifice 46 communicating with the working chambers a and b.
c, 46d are provided, and the hydraulic working chamber a,
One-way valves 46e and 46f that prevent the flow of hydraulic oil from b to the oil tank are provided.

Here, as shown in FIGS. 2 and 4, the normal main oil passage 27a has the forward rotation side hydraulic pressure generating chambers A, C, E and G as the oil passage 30b of the main body portion 30a, the hydraulic working chamber b, Movable side plate 4
4, the oil tank 38 through the orifice 46d
Is in communication with.

The sub-main oil passage 27b connects the reverse rotation side oil pressure generating chambers B, D, F and H to the oil tank through the oil passage 44d in the movable side plate 44, the hydraulic pressure operating chamber a and the orifice 46c. 38.

The primary and secondary oil passage 50a connects the oil tank 38 and the primary main oil passage 27a via the one-way valve 46f. The reverse sub oil passage 50b connects the oil tank 38 and the reverse main oil passage 27b via the one-way valve 46e.

That is, the hydraulic pressure generating chambers A, C, E on the forward rotation side,
The pressure of G is such that the orifice 46d and the one-way valve 46f arranged between the oil pressure generating chamber and the oil tank 38.
As a result, the pressures in the positive-side hydraulic working chamber b and in the reverse-side hydraulic generating chambers B, D, F, and H are controlled by the orifice 46c and the one-way valve 46e arranged between the hydraulic generating chamber and the oil tank 38. Thus, each of them acts on the opposite hydraulic working chamber a.

Next, the function and effect will be described. For example,
When the front wheel rotation speed and the rear wheel rotation speed are the same at low speed traveling, the casing 29 and the retainer 30 have the same rotation speed. Therefore, the driven gear 31 and the ring gear 32
There is no relative rotation between and and no hydraulic pressure is generated, so there is no increase in torque transmission to the front wheels 24. At this time, the weight 41 does not move in the radial direction because sufficient centrifugal force is not exerted because it is traveling at a low speed.

When the rear wheel rotation speed becomes higher than the front wheel rotation speed due to slip of the rear wheel 22, the rotation speed of the casing 29 becomes higher than that of the retainer 30, and the ring gear 32,
The driven gear 31 rotates in the direction of arrow a in FIG. In this case, for example, when focusing on the driven gear 31 ', the hydraulic pressure generation chamber A is the discharge side and the hydraulic pressure generation chamber H is the suction side. The hydraulic oil discharged from the hydraulic pressure generating chamber A flows into the positive hydraulic pressure operating chamber b from the oil passage 30b. And
The hydraulic oil is blocked from flowing into the oil tank 38 by the one-way valve 46f, and the orifice 46d
The front wheel 24
Is also transmitted to. Further, at this time, the movable side plate 44 is driven by the hydraulic pressure to drive the gear 31 and the retainer main body 30.
a and the left end surface in the figure of the ring gear 32 are pressed, and the right end surface in the figure presses the seal plate 43, thereby preventing oil leakage from the left and right end surfaces of the hydraulic pressure generating chamber.

Next, at the time of high speed rotation, in FIG. 3, the weight 41 moves radially outward from the shaft center side by the centrifugal force, and the cam 42 causes the main body 30 of the retainer 30 to move.
The movable side plate 44 is pressed to the left in the drawing via a or the like, whereby the male taper surface 44a and the female taper surface 47a are connected, and as a result, the rotation of the casing 29 causes the retainer 3 to rotate.
Even if there is no speed difference, the torque is transmitted to the front wheels as so-called initial torque.

When a difference in the number of revolutions occurs at the time of this high speed rotation, the transmission torque is increased by the pressure increase of the hydraulic oil and the movable side plate 44 is pressed rightward in FIG. , Surely prevent oil leakage from the right end face.

When the rotation speed of the front wheel 24 becomes higher than the rotation speed of the rear wheel 22 due to the slip of the front wheel 24 or the like, the hydraulic pressure generating chamber H becomes the discharge side and the hydraulic pressure generating chamber A becomes the suction side contrary to the above. . In this case, the hydraulic oil is the reverse main oil passage 27b.
Acts on the reverse hydraulic pressure operating chamber a to actuate the movable side plate 44 in the same manner as above to prevent oil leakage.

When the rotation directions are different from each other in the forward and reverse directions as described above, the orifice 46d is provided in the forward direction and the orifice 46c is provided in the reverse direction even if the rotational speed difference is the same. By appropriately setting these orifice diameters, different torques can be transmitted.

As described above, in this embodiment, the orifice 46 is used.
forward and reverse main oil passages 27a and 27b for connecting the oil pressure generating chambers (A to H) to the oil tank 38 via d and 46c,
Orifices 46d, 46c of the main oil passages 27a, 27b
Since the oil tank 38 and the oil pressure generating chambers (A to H) communicate with each other via the one-way valves 46f and 46e, the forward and reverse auxiliary oil passages 50a and 50b are provided. H) Power can be transmitted without separately providing a forward rotation valve and a reverse rotation valve for each.

Further, the normal and reverse hydraulic pressure operating chambers b, which communicate with the orifices 46d and 46c of the normal and reverse main oil passages 27a and 27b and the hydraulic pressure generating chambers (A to H) to cause the hydraulic pressure to act on the movable side plate 44, Since a is provided, the hydraulic oil can always act on the movable side plate 44 regardless of the difference in the number of rotations, either forward or reverse, and the number of parts and the number of processing steps can be reduced to suppress the cost and ensure the oil leakage. It can be prevented.

Furthermore, the number of one-way valves is reduced, the space for arranging the valves is reduced accordingly, and the degree of freedom in the size of the retainer 30 is increased. Therefore, it is possible to reduce restrictions on the number and diameter of the driven gears 31. The transmission capacity can be increased, and when transmitting the same driving force, the device can be made smaller than the conventional example.

Further, since the different orifices 46d and 46c are used during the forward and reverse rotations, different transmission torques can be set during the forward and reverse rotations.

[0040]

As described above, according to the hydraulic power transmission device of the present invention, power can be transmitted by a simple structure of a set of one-way valve and orifice, and the hydraulic pressure can always act on the movable side plate. Therefore, it is possible to reduce the number of parts and the number of processing steps, and to prevent the oil leakage while suppressing the cost. In addition, the number of driven gears can be increased and the transmission torque capacity can be increased as much as the one-way valve installation space is small, and further, the transmission torque can be set to different arbitrary values during forward and reverse rotations. is there.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a four-wheel drive vehicle including a hydraulic power transmission device according to an embodiment of the present invention.

FIG. 2 is a schematic system diagram showing a hydraulic oil flow path of the above embodiment.

FIG. 3 is a sectional side view of the above embodiment.

FIG. 4 is an enlarged view of a main part of FIG.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a cross-sectional side view of essential parts of a hydraulic power transmission device of a first conventional example.

FIG. 7 is a schematic system diagram showing a hydraulic oil flow path of a power transmission device proposed by the present applicant.

[Explanation of symbols]

 26 Hydraulic Power Transmission Device 27a, 27b Direct, Reverse Main Oil Path 29 Casing 30 Retainer 31, 31 'Driven Gear 32 Ring Carrier 38 Oil Tank 44 Movable Side Plate 46c, 46d Orifice 46e, 46f One Way Valve 50a, 50b Normal, Reverse Secondary Oil Path b, a Forward / reverse hydraulic pressure working chamber A to H Forward / reverse hydraulic pressure generating chamber

Claims (1)

[Claims] 1. A retainer to which a second rotary shaft is connected is coaxially arranged in a casing to which a first rotary shaft is connected,
A driven gear rotatably supported by the retainer is meshed with a ring gear provided on the inner surface of the casing, and the casing, the ring gear, the driven gear and the retainer form a forward and reverse hydraulic pressure generating chamber, and an operation in the hydraulic pressure generating chamber. A hydraulic power transmission device for transmitting power between the first rotary shaft and the second rotary shaft by increasing the pressure of oil by the ring gear and the driven gear according to the rotation difference between the first and second rotary shafts. In the above, the forward and reverse main oil passages that connect the forward and reverse oil pressure generating chambers and the oil tank to each other through an orifice, and the orifices of the forward and reverse main oil passages and the oil tank that communicates between the oil pressure generating chambers. , A reverse auxiliary oil passage, a one-way valve arranged in the normal and reverse auxiliary oil passages for preventing the flow of the hydraulic oil from the hydraulic pressure generating chamber to the oil tank, and one end of the driven gear in the axial direction. Forward and reverse hydraulic actuation in which hydraulic pressure is applied to the movable side plate by communicating with the movable side plate that is slidably contacted with the movable side plate and is arranged to be movable in the axial direction, the orifice of the normal and reverse main oil passages, and the hydraulic pressure generation chamber. A hydraulic power transmission device including a chamber.