JPS63101526A - Driving link device - Google Patents

Abstract

PURPOSE:To prevent any cavitation by providing a small passage which makes operating fluid flow out from a delivery side chamber to a suction side chamber. CONSTITUTION:Many channels 19b are formed in the outer periphery surface 19a of a rotor 19 at equal intervals in periphery direction on a vane pump VP. Vanes 18, that can make slidable contact with the inner periphery surface 20d of a cam ring 20a, are fitted in said channels. Three pump chambers 36-38 and suction/delivery ports 22-27 are mutually connected through the first oil passage OL1 and the second oil passage OL2 respectively. Hereupon, orifices 18c are provided on respective vanes 18 as small passages, therefore oil flows through orifices 18c from a delivery side chamber to a suction side chamber following the movement of vanes 18 in pump chambers 36-38 due to the relative rotation of the rotor 19 to the cam ring 20a. Thereby, generation of any cavitation in a suction side chamber is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a drive coupling device that connects two rotating shafts using fluid pressure to reduce the difference in rotational speed between the two rotating shafts.

<Prior art> For example, in a four-wheel drive vehicle in which the front wheels and rear wheels are driven by the same engine, a rotating shaft connected to the front wheels and a rotating shaft connected to the rear wheels are connected by fluid pressure such as oil pressure. A drive coupling device has been developed and has already been filed.

FIG. 13 is a schematic cross-sectional view of the conventional drive coupling device. In the figure, 2° is a housing connected to a first rotating shaft connected to the front wheel, and 19 is a housing connected to a second rotating shaft 14 connected to the rear wheel and housed in the housing 20. The rotor 18 is provided with a large number (10 vanes in this case) on the outer periphery of the rotor 19 and is in sliding contact with the inner peripheral surface of the housing 20. The vanes 36, 37, and 38 are defined by the housing 20 and the rotor 19, respectively. pump chambers, 22, 23, 24, 25, 26; 27 is a suction and discharge port opened at both ends of the pump chambers 36, 37, and 38, respectively; OL is a first oil port that communicates with the suction and discharge ports 22, 24, and 26; OL2 is the suction and discharge port 23.・Second oil passage connecting 25 and 27, 30 is each check valve 28°2
The oil reservoir 33 is an orifice provided in the oil passage 34 that communicates the first oil passage OL and the second oil passage OL. be. Then, a rotation speed difference occurs between the first rotation shaft and the second rotation shaft 14, that is, between the housing 20 and the rotor 19, and the rotor 19 moves in the direction shown by the arrow in the figure, for example, with respect to the housing 20. When relatively rotated, the suction and discharge ports 22,
24.26 serves as a discharge port, and the vane 18 discharges the hydraulic oil from the pump chamber 36°37.38 to the first oil passage OL, while the suction and discharge ports 23, 25.27 serve as suction ports, and the second oil It operates as a pump that sucks hydraulic oil from passage OL2 into pump chamber 36°37.38. The above first oil path OL
The oil discharged to the second oil passage OL2 flows through the oil passage 34, and at this time, resistance is applied by the orifice 33 according to the flow rate. Therefore, when a slip occurs between the front wheels and the rear wheels and a difference in rotational speed occurs between the housing 20 and the rotor 19, the difference in rotational speed causes the operation 1! Resistance is added according to the flow rate of I oil,
A four-wheel drive state is achieved by reducing this rotational speed difference. In addition, during the above action, the housing 20 and the rotor 1
Hydraulic oil is replenished from an oil reservoir 30 in case of oil leakage from the seal portion 9.

Further, a hydraulic chamber 59 is provided at the bottom of the vane 18 of the rotor 19, and the hydraulic chamber 59 is connected to the first
It can communicate with the h path OL and the second oil path OL2. Therefore, the oil discharged from the first oil passage OL (or the second oil passage 0L2 in the case of reverse rotation) is transferred to the check valve 39 (4).
When the pump is operated, the vane 18 is pushed up and brought into pressure contact with the inner circumferential surface of the housing 20, thereby improving liquid tightness.

<Problems to be Solved by the Invention> As mentioned above, in the conventional drive coupling device, the discharge hydraulic pressure is guided to push up the vane 18 to improve liquid tightness. There was a problem that the functional warehouse could not be fully utilized. That is, after all the discharged oil is guided to the first oil 1@OL□ or the second oilway OL2 formed in the housing 20, the second oilway OL serves as a suction side oilway for the discharged oil, or the first oil passage OL, and also the vane push-up hydraulic chamber 59, so that the first oil passage O
L1. A large amount of hydraulic oil will flow through the circuit consisting of the second oil passage OL, etc. Therefore, the oil pressure decreases due to flow path resistance, and the oil pressure supplied to the oil pressure chamber 59 decreases with respect to the discharge oil pressure in the pump chambers 36, 37, and 38, and the vane 1
In some cases, it was not possible to maintain liquid tightness between the housing 8 and the inner peripheral surface of the housing 2. In such a case, when the discharge oil pressure (torque transmission oil pressure) becomes high to a certain extent, the vane 18 retracts and the discharge oil leaks from the discharge side chamber of the pump chamber to the suction side chamber, and the fourteenth Fluctuations in the transmitted torque as shown in the figure occur.

Also, a first oil passage OL from the suction and discharge port on the discharge side.

Since the hydraulic pressure led to the suction-side suction-discharge port through the second oil f%l0L2 becomes a large negative pressure state depending on the flow l, caviteller 9 may occur near the suction-side suction-discharge port. This also causes fluctuations in the transmitted torque.

The present invention was made in view of the above-mentioned conventional circumstances, and it is an object of the present invention to provide a V-dynamic coupling device that can maintain the liquid-tightness of vanes and prevent cavitation from occurring, thereby achieving stable torque transmission. shall be.

Means for Solving the Problems> The drive coupling device of the present invention comprises: a housing coupled to a first rotating shaft; a rotor coupled to a second rotating shaft and housed in the housing; a plurality of vanes provided on the outer circumferential surface of the rotor and on the inner circumferential surface of the housing to partition the pump chamber defined by the housing into a discharge side chamber and a suction side chamber; The working fluid pressurized in the discharge side chamber is guided by the vane to the bottom of the vane due to the relative rotation between the housing and the rotor due to the rotational speed difference between the rotation shaft and the second rotation shaft, and the vane is activated. The present invention is characterized in that a small passage is provided which is brought into pressure contact with the inner circumferential surface of the housing and allows the working fluid to flow out from the discharge side chamber to the suction side chamber.

Function> Discharged fluid from the discharge side chamber of the pump chamber is mainly guided to the suction side chamber through a small passage without causing cavitation, and the fluid pressure resistance added by the small passage causes the housing (first rotating shaft) to Torque is transmitted between the rotor and the rotor (second rotating shaft). Since the discharge fluid pressure is guided to the bottom of the vane through a circuit different from the one described above, the flow rate flowing through this circuit is reduced and a pressure drop is avoided. Therefore, fluid pressure close to the discharge fluid pressure is guided to the bottom of the vane, and high liquid tightness is maintained by pushing up the vane.

Embodiment One embodiment of the present invention will be described based on the drawings. In this embodiment, the drive coupling device is applied to a four-wheel drive vehicle, and FIG. 1 is a schematic cross-sectional view of the drive coupling device, FIG. 2 is a schematic configuration diagram showing the drive system of the vehicle, and FIG. FIG. 3 is a longitudinal sectional view of the drive coupling device.

As shown in Fig. 2, a transmission 2 is attached to an engine 1 placed horizontally.
are connected, and the drive gear (
The driving force is taken out from the 4-speed counter gear (4-speed counter gear) 4 and transmitted to the gear cam ring 20e of the vane pump type drive coupling device main body 13.

The gear cam ring 20e rotates the housing 20 and connects to the first rotating shaft (
The differential value [1
'tE power is transmitted to the front wheel 9 to drive the front wheels 9.

That is, the driving force transmitted to the drive coupling device main body 13 is directly transmitted to the first rotating shaft 11 via the gear cam ring 20θ, and further transmitted to the front wheels 9 via the gear 7 and the differential device 10. .

The driving force passing through this drive coupling device main body 13 is transferred to a second rotating shaft (inner shaft) coaxially arranged with the first rotating shaft 11.
14, a bevel gear that changes the direction of rotation! The driving force is transmitted to the differential gear 17 for the rear wheels 16 via the propeller shaft 12, the propeller shaft 12, and the bevel gear mechanism 15', thereby driving the rear wheels 16.

As shown in FIGS. 1 and 3, this drive coupling device main body 13 includes a vane pump vP and a hydraulic circuit 2 attached thereto.
1 and the rotor 19 of the vane pump ■P.
is connected to the second rotating shaft 14 that transmits driving force to the rear wheel 16, and the cam ring portion 20a and flange 20a that constitute the housing 20 connect to the first rotating shaft 11 that transmits driving force to the front wheel 9. is connected to.

In the vane pump vP as this hydraulic pump, a large number (10 holes in this case) of holes 19b are formed at equal intervals in the circumferential direction on the outer peripheral surface 19m of the rotor 19, and each of the large number of holes 19b A vane 18 that can come into sliding contact with the inner circumferential surface 20d of the cam ring portion 20a is fitted into the cam ring portion 20a.

Further, each part is formed so that the axial clearance between the cover 20b of the housing 20 and the vanes 18 and rotor 19 is below a predetermined value, so that the oil film does not break and the pressure of the housing 20 is reduced. Retainer 2Of
Similarly, each part is formed so that the axial clearance between the vane 18 and the rotor 19 is equal to or less than a predetermined value.

The sum of these gaps is set to be less than or equal to a predetermined value.

Further, the vane pump VP generates hydraulic pressure proportional to its rotation speed, and the vane pump VP generates hydraulic pressure proportional to its rotation speed, and is connected to the rotor 19 and the cam ring part 20.
When a relative rotation occurs between the first rotating shaft 11 and the second rotating shaft 14, the first rotating shaft 11 and the second rotating shaft 14 function as a hydraulic pump and generate hydraulic pressure. Therefore, by restricting the flow of oil discharged from the vane pump (P), the rotor 19 and the cam ring portion 20a can be rotated as a rigid body by the static pressure of the oil.

Three pump chambers 36 to 38 are formed between the cam ring part 20a and the rotor 19 at intervals of 120° from the rotation center line, and when they are not located on the base end side in the rotational direction, they serve as suction ports and are located on the distal end side. Six suction and discharge ports 22 to 27, which serve as discharge ports when
4, 26 and the suction/discharge ports 23, 25.27 are the first oil passages OL! and a second oil passage OL2.

Here, each of the vanes 1B is provided with an orifice 18c as a small passage, and as the vane 18 moves within the pump chambers 36 to 38 due to the relative rotation between the rotor 19 and the cam ring portion 20a, the pump chamber 36 Oil flows from the discharge side chamber to the suction side chamber through the orifice 18c, and the oil flows through the first oil passage OL or the second oil passage OL.

There is only a small amount of flow to the vane, which will be described later. The number or diameter of the orifice 18c is appropriately set according to the torque transmission characteristics (see Fig. 4) described later, and the installation position of the orifice 18c is such that the vane 18 is located at least within the pump chambers 36 to 3B. Any position that opens when the maximum lift is achieved is sufficient.

Also, the oil F at the bottom of the transmission case 44 is connected between the first oil passage OLl and the second oil passage OL via check valves 28 and 29, respectively. l (oil tank) 3G
are communicated with each other from oil @aO to each oil path OL1. Only flow to OL2 is allowed.

Further, the cover 20b and seven flange 20a that constitute the housing 2G of the vane pump vP are each pivotally supported by the transmission heavy case 44 via bearings 41 and 42.

Spline engagement part 14 on q-19 of vane pump vP
The 20th rotating shaft 14 connected via a has bushings (bearings) 45 on both sides of the spline retaining portion 14a.
．． The cover 20b and the pressure retainer 20f are respectively pivotally supported via 46.

The vane 1B receives discharge hydraulic pressure from its bottom portion 18b, and its tip portion 18a is connected to the inner circumferential surface of the cam ring portion 20m.
0d to maintain liquid tightness. That is, the axial sliding portion 56 where the rotor 19 and the cover 20b are in sliding contact, and the rotor 19 and the pressure retainer 20
As shown in FIG. 3, an annular hydraulic pressure of 1159° 59 is formed in the axial sliding portion 56 in sliding contact with The first oil passage OL communicates with the first oil passage OL via check valves 39 and 40 that allow oil to flow only to these oil pressure chambers 59 and 59.
, and the second oil passage OL. Therefore, the first oil path OL! Or, the high-pressure discharge hydraulic pressure that is not guided to the second oil @OL flows into the hydraulic chamber 59 via the check valve 39 or 40.
, 59, which pushes up the vane 18 and maintains liquid tightness.

Furthermore, a spring 63 or a ring or the like as shown by the two-dot chain line in FIG.
5 at a time through the bottom 18b of the vane 18.
You may also press the button.

Reference numeral 19e in the figure indicates the bottom of the inner diameter side of the rotor 19;
3 indicates a bearing that supports the first rotating shaft,
47 is Palsage.

48 is an oil guide, 49 is a filter,
50 indicates a magnet, and 51 indicates a bolt.

According to the drive coupling device configured as described above, when the vehicle is in a normal straight-ahead state, there is almost no difference in rotational speed between the front wheels 9 and the rear wheels 16, and there is little difference in rotational speed between the first rotational shaft 11 and the second rotational shaft 14. If there is no rotational speed difference between the vane pump vP
No oil pressure is generated at this time, and the front wheels are driven only by the front wheels 9, with no driving force being transmitted to the rear wheels 16.

In addition, slipping or the like occurs in the front wheels 9, and the rotational speed of the front wheels 9 becomes larger than that of the rear wheels 16, causing the first rotation shaft 11 and the second
When a rotational speed difference occurs between the rotating shaft 14 and the rotating shaft 14, hydraulic pressure is generated in the vane pump vP, resulting in a four-wheel drive state in which this rotational speed difference is reduced or eliminated. In this case, the rotor 19 rotates relative to the housing 20 in the direction shown by arrow B in FIG.
4.26 is the discharge side, and the suction and discharge ports 23, 25, and 27 are the suction side. In addition, the solid line arrow in FIG. 1 shows the flow of discharged oil, and the broken line arrow shows the flow of the suction part. and,
Oil flows from the discharge side chamber of the pump chambers 36 to 38 to the suction side chamber through the orifice 18c, but the rotational speed difference between the rotating shafts 11 and 14 increases (as the oil flow rate increases, the oil flows through the orifice 18a). Since the flow resistance increases, the rotational speed difference is reduced, and the driving force is also transmitted to the rear wheels 16 with a quadratic characteristic as shown by the solid line in FIG.

Here, from the suction discharge ports 22, 24, 26 to the first oil path OL.
,,The tip of the vane 18 is pressed against the inner circumference [20d] of the cam ring part 20m by the discharged oil pressure guided to the hydraulic chambers 59, 59 via the check valve 39, but as mentioned above, the discharged oil is Since most of the oil flows through the orifice 18c and the flow rate of the discharged oil to the hydraulic chambers 59 and 59 is small, the discharged hydraulic pressure remains in a high pressure state without causing a pressure drop in the first oil passage OL and the check valve 39. 5
9, the driving force is transmitted without causing torque fluctuation due to the high liquid tightness of the vane 18. In addition, the oil supplied from the discharge side chamber to the suction side chamber is not supplied through long oil passages such as the first oil passage OL and the second oil @QL as in the conventional system, so there is no cavity in the suction side chamber. Since the occurrence of warpage is prevented, torque fluctuation is also prevented from occurring. Note that hydraulic oil is replenished from the oil reservoir 30 in case of oil leakage from the seal portion of the housing 20 or the rotor 19, as in the conventional case. In addition, while the above-mentioned four-wheel drive characteristics can be made gentler as shown by S in FIG. The reaction can be explained as shown by H. By the way, when the diameter of the orifice 18c is 0.5 m and the difference in rotational speed is I Q Orpm, the discharge oil pressure is ZOOkg/
c+/ (equivalent to a transmission torque of 50 kgm).

On the other hand, contrary to the above, the rotational speed of the rear wheel 16 is higher than that of the front wheel 9.
When the rotational speed of the vane pump vP increases, oil flows in the opposite direction to the above, and the suction and discharge ports 22,
24, 26 are suction side, suction discharge port 2: l, 25, 2? is on the discharge side, and the discharge hydraulic pressure is guided to the hydraulic chambers 59 and 59 via the second oil MaOL2 and the check valve 40, and the four-wheel drive state is achieved by the same action as described above. In addition,
By causing the vane pump vP to rotate in the reverse direction in this way, even if the orifice 18c should become clogged with dirt, this dirt will be automatically removed, making maintenance easy. (a) is a front view showing a vane according to another embodiment of the present invention, and FIG. 5fb) is a longitudinal sectional view of a drive coupling device using the vane. In this embodiment, instead of providing an orifice in the vane 18, a notch 18d is provided at the tip corner of the vane 18, and thereby the pump is provided at the corner between the inner peripheral surface 20d of the cam ring portion 20a and the inner wall surface of the cover 20b. A small passage is formed through which oil flows from the discharge side chambers of the chambers 36 to 38 to the suction side chambers. The cross-sectional area of this small passage corresponds to a circle of approximately 0.3 pus, and such a small passage also provides a predetermined fluid pressure resistance to the oil flowing from the discharge side chamber to the suction side chamber, and has the same effect as the orifice 18c. be effective. Of course, the notch 18d may be provided at the corner of the vane 18 on the left and right sides opposite to the above, and a small passage may be provided at the corner between the inner circumferential surface 20d of the cam ring portion 20a and the inner wall surface of the pressure retainer 2Of.

FIGS. 6 to 8 are front views of vanes showing aspects for forming small passages from the same viewpoint as above. That is, the one shown in No. 6'Ig has a notch 18e on the tip edge of the vane 18, and the one shown in FIGS. 7 and 8 has notches 18f and 18g on the side edge of the vane 18. , these notches 18e, 18f.

18g also provides the same effect as the orifice 18c as well as the notch 18d.

FIG. 9 is a schematic cross-sectional view of a drive coupling device according to yet another embodiment of the present invention, and FIG. 10 is a longitudinal sectional view of the drive coupling device. In this embodiment, instead of providing a small passage in the vane 18, a groove 18h is provided in a portion of the inner circumference g20d of the cam ring portion 20a facing each of the pump chambers 36 to 38, thereby allowing the discharge side chambers of each of the pump chambers 36 to 38 to be A small passageway is formed through which oil flows out into the suction side chamber. The cross-sectional area of this small passage also corresponds to a circle of approximately 0.3 mm, and such a passage also provides a predetermined fluid pressure resistance to the oil flowing from the discharge side chamber to the suction side chamber, and achieves the same effect as the orifice 18c. play.

FIG. 11 is a schematic cross-sectional view of a drive coupling device according to yet another embodiment in which a small passage is formed from the same viewpoint as the above, and FIG. 12 is a longitudinal sectional view of the drive coupling device. In this embodiment, an annular groove 18i is provided on the inner wall surface of the cover 20b or an annular groove 18j is provided on the inner wall surface of the pressure retainer 20f, thereby allowing air to flow from the discharge side chambers of each pump chamber 36 to 38. A small passageway is formed through which oil flows out into the suction side chamber. In this embodiment, the grooves 18i, 18j
Since it is annular, it is easier to process than providing the groove 18h. Although FIG. 12 shows an embodiment in which both the groove 18i and the groove 18j are provided, only one of them may be provided.

Note that the orifice 18C1 notch 18 shown in the above embodiment
The small passages may be formed by other modes of the grooves 18h to 18j of d to 18g, or a combination of several small passages formed by each mode may be applied.

Although the above embodiment is applied to a four-wheel drive vehicle, the drive coupling device of the present invention can of course be used for coupling a general power source and a driven machine.

<Effects of the Invention> According to the drive coupling device of the present invention, fluid pressure (hydraulic pressure) that is extremely close to the fluid pressure (hydraulic pressure) generated in the pump chamber can be guided to the bottom of the vane, thereby increasing the fluid tightness of the vane. It is possible to achieve driving force transmission while automatically reducing the rotational speed difference between the two shafts in a state where there is no torque fluctuation. Furthermore, since the working fluid is fed from the discharge side chamber of the pump chamber to the suction side chamber through the small passage, it is possible to avoid the generation of a negative pressure state in the suction side chamber and prevent the generation of cavity silane. Furthermore, when the present invention is applied to a four-wheel drive vehicle, it is possible to automatically achieve a four-wheel drive state with a small, simple, and low-cost structure.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view of a drive coupling device according to an embodiment of the present invention, Fig. 2 is a schematic configuration diagram showing a drive system of a vehicle to which the present invention is applied, and Fig. 3 is a drive coupling device. FIG. 4 is a graph showing the relationship between rotational speed difference and transmitted torque; FIG. 5 is a front view of a vane according to another embodiment of the present invention; FIG. 5(b) 6 to 8 (f) are a front view of the vane each showing an aspect of forming a small passage, and FIG. 9 is a longitudinal sectional view of a drive coupling device using the vane, and FIG. FIG. 10 is a vertical cross-sectional view of the drive coupling device according to the present invention, and FIG. 11 is a schematic cross-sectional view of the drive coupling device according to another embodiment of the present invention. Fig. 12 is a longitudinal sectional view of the drive coupling device, Fig. 13 is a schematic diagram of the conventional drive coupling device, and Fig. 14 is a graph showing fluctuations in transmission torque. 14 is a second rotating shaft, 18 is a vane, 18c is an orifice 1, 18d to 18g are notches, 18h to 18j are grooves, 19 is a rotor, 20 is a housing, 20a is a cam ring portion, 36.37. 38 is a pump chamber, and 59 is a hydraulic chamber.

Claims (3)

[Claims] (1) A housing connected to a first rotating shaft, a rotor connected to a second rotating shaft and housed in the housing, and a rotor provided on an outer circumferential surface of the rotor and an inner circumferential surface of the housing. a plurality of vanes slidingly in contact with each other to partition a discharge side chamber and a suction side chamber into a pump chamber defined by the rotor and the housing, the rotation speed of the first rotation shaft and the second rotation shaft; Due to the relative rotation between the housing and the rotor due to the difference, the working fluid pressurized in the discharge side chamber is guided by the vane to the bottom of the vane to press the vane against the inner circumferential surface of the housing, and the discharge A drive coupling device characterized in that a small passage is provided for causing the working fluid to flow out from the side chamber to the suction side chamber. (2) The drive coupling device according to claim 1, characterized in that a small passage is provided in the vane. (3) The drive coupling device according to claim 1, wherein the small passage is provided in a member forming a wall surface of the pump chamber.