JPS60228785A - Vane pump - Google Patents

Abstract

PURPOSE:To minimize leakage of oil from a gap between a rotor and a cam ring by having belt-like or linear springs abut each internal peripheral edge part of each vane to urge the vanes against the internal periphery of the cam ring. CONSTITUTION:Belt-like ring-like spring 52 and 53 are provided at the side end parts of the cover 20b of a rotor 19 and at the side end part of a pressure retainer 20f, respectively. Said springs abut the internal peripheral edge part of each vane 18, urging the vanes against the internal peripheral face 20d of a casing 20. The ring-like springs are placed in recesses 18a formed on each of the vanes, and made of spring steel shaped in the form of endless belt and having low rigidity and high elasticity.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a vane pump, and particularly to a vane pump suitable for use in a front and rear wheel drive coupling device of a vehicle.

[Conventional technology]

Generally, the front and rear wheels are driven by the same engine.
In wheel drive (4WD) vehicles, there is a slight difference in the effective radius of the front and rear tires, and differences in the rolling paths of the wheels when turning can cause the tires to slip and cause unreasonable force to be applied to the drive system. Therefore, it is necessary to provide a means to prevent this.

For this reason, conventionally, in full-time four-wheel drive vehicles, there is a rotational speed difference between the first rotating shaft that transmits driving force to the front wheels and the second rotating shaft that transmits driving force to the rear wheels. A differential device called a center differential is used in order to transmit driving force, which is disadvantageous compared to part-time 4-wheel drive vehicles in terms of weight, size, and cost, and because differential rotation is possible. When four-wheel drive is required, it may not be possible to achieve four-wheel drive, and the device becomes even more complex, such as requiring a differential locking mechanism.

On the other hand, many part-time 4-wheel drive vehicles do not have a center differential, and if there are problems with 4-wheel drive such as tight corner braking caused by cornering, the driver must operate 2-wheel drive. However, there is a drawback that the driving operation is complicated.

Therefore, a vane pump type coupling mechanism that can mutually transmit driving force between the first rotating shaft and the second rotating shaft is provided.
A drive coupling for wheel drive is also conceivable.

[Problem that the invention seeks to solve]

However, in such a vane pump type connection (a four-wheel drive drive connection device equipped with several structures), when the vane pump rotates at high speed, the centrifugal force acting on the vane pushes the vane one inch against the inner peripheral surface of the cam ring. Although oil leakage from the gap between the rotor and the vane and the cam ring portion in sliding contact with the vane on the inner circumferential surface of the casing is small, there is a problem in that the oil leakage increases when the vane pump rotates at low speeds.

Furthermore, heat due to oil leakage is also generated, increasing the oil temperature.

When the oil temperature increases, the viscosity of the oil decreases, and leakage from seals in various parts of the pump increases, making it impossible to obtain the desired discharge pressure characteristics, resulting in a decrease in transmitted torque.

In order to deal with this oil leakage, the conventional vane pump VP has a
■■ Cross-sectional view of the arrow) 1 As shown, hole 1 of rotor a
9 (front view) and 10 (torsion coil spring type) which urges the inner peripheral surface f of the cam ring part e by the coil spring d of the vane C installed in the As shown in the front view), a torsion fill spring g is fixed to the rotor a with a pin 11, and both ends of the torsion coil spring g press against the base end on the inner peripheral side of the vane C, so that the vane C is attached to the cam ring part. A rocker arm type has been proposed that urges the inner circumferential surface f of e.

However, such conventional vane pumps have the problem of being unable to take an appropriate load or spring constant due to dimensional constraints, and have a complex structure that makes assembly difficult.

Furthermore, the rocker arm type has the problem that the number of vanes may be limited to an even number and is difficult to apply to a vane pump having an odd number of vanes.

The present invention aims to solve these problems, and provides a vane pump that can reliably prevent oil leakage during low-speed rotation of the vane pump and improve its driving force transmission efficiency. The purpose is to

[Failure to solve the problem]

Therefore, the vane pump of the present invention includes a casing connected to a first rotating shaft, a rotor connected to a second rotating shaft and housed in the casing, and a rotor attached to the outer circumferential surface of the rotor. The vane biasing mechanism includes a large number of vanes that slide in contact with the cam ring on the inner peripheral surface of the casing, and a vane biasing mechanism that biases the large number of vanes toward the cam ring. It is characterized by being constructed by a band-like or linear spring that comes into contact with each inner peripheral side base end.

[For production]

With the above-described configuration, the vane is always urged against the inner peripheral surface of the cam ring, thereby reducing oil leakage from the gap between the rotor and the cam ring.

〔Example〕

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
Figures 1 to 6 show a four-wheel drive drive coupling device equipped with a vane pump as an embodiment of the present invention. Figure 1 is a cross-sectional view of this device, and Figure 2 shows a vehicle drive system. 3 is a longitudinal cross-sectional view of the device, and FIG. 4(a) to (
, I) are graphs showing the discharge pressure of the vane pump,
FIG. 5 is a cross-sectional view of the main part thereof, and FIG. 6 is a cross-sectional view of a modification of the present device shown in correspondence with FIG. 1.

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 four-speed counter gear (4-speed counter gear) 4 and transmitted to the gear cam ring 20e of the four-wheel drive drive coupling device main body 13 as a vane pump type coupling mechanism.

The gear cam ring 20e rotationally drives the casing 20, and the rotating shaft @1 (
differential gear 1 for the front wheels 9 from the gear 7 via the outer shaft) 11
01 driving force is transmitted and the front wheels 9 are driven.

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

The driving force passing through the four-wheel drive drive coupling device main body 13 is transferred to a second rotating shaft (
The driving force is transmitted to the rear wheel 16 differential device 17 via a bevel gear mechanism IS, 15' that changes the direction of rotation.
Drive 6.

As shown in FIGS. 1 and 3, this four-wheel drive drive coupling device main body 13 is composed of a vane pump ■P serving as a hydraulic pump (hydraulic coupling mechanism) and a hydraulic circuit 21 attached thereto. The rotor 19 of the vane pump ■P is the rear wheel 1
A cam ring portion 20a that is connected to the second rotating shaft 14 that transmits driving force to the cam ring 6 and that constitutes the casing 20.
The flange 20c is connected to the first rotating shaft 11 that transmits driving force to the front wheel 9.

The vane pump VP as a hydraulic pump has a large number (14 holes in this case) of a shape #i on the outer circumferential surface 19a of the rotor 19 at equal intervals in the circumferential direction. 19'b each has a cam ring part 2.
A vane 18 that can be slidably contacted with the inner circumferential surface 20d of Oa is fitted.

Furthermore, each part is formed so that the axial clearance between the cover 20b of the casing 20 and the vanes 18 and rotor 19 is below a predetermined value, so that the oil film does not break, and the pressure retainer of the casing 20 is 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.

In addition, the vane pump ■P discharges an amount of oil 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 rotary shaft 11 and the second rotary shaft 14, it functions as a hydraulic pump and generates hydraulic pressure.

Discharge ports of the vane pump VP (suction and discharge ports 22 to 27 at the tips of the vanes 18 in the relative rotational direction with respect to the casing 20)
(equivalent to this), the rotor 19 and the cam ring portion 20a become like a rigid body and are rotated together by the static pressure via the oil.

Therefore, between the cam ring portion 20a and the rotor 19, there are three pump chambers 36 to 36 at intervals of 120 degrees from the rotation center line.
38 is formed, and six suction and discharge ports 22 to 27, which are the suction port when located on the proximal end side in the rotational direction and the discharge port when located on the distal end side, are formed at approximately 120° intervals, Suction/discharge ports 22, 24.26 and suction/discharge ports 23, 25.27 spaced apart by 120 degrees, each having the same function,
The first oil passage OL and the second oil passage O are connected to each other through a mechanism that allows oil to flow to the stationary side even when the cam ring portion 20a is rotating.
It is communicated with L2.

Further, an oil reservoir 30 is communicated between the first oil passage OL and the second oil passage OL2 via check valves 28, 29, 29', respectively, and the oil reservoir 30 is connected to each oil passage OL, OL2.
Only the flow to the first oil path OL is allowed.

and the second oil passage OL2 via two opposing check valves 31, 32 that allow only outflow.

OL2 is in communication, and an intermediate portion between the two check valves 31 and 32 is in communication with the relief valve 33 via an oil passage 40.

A communication passage 35 is provided between the oil reservoir 30 and the check valve 29' and the two check valves 28 and 29 through the intermediate portion of the relief valve 33 on the spring 34 side.

With such a hydraulic circuit 21, the discharge pressure always acts on the valve body of the relief valve 33, regardless of the relative rotation direction between the rotor 19 and the cam ring portion 20a, and the oil reservoir 30 communicates with the suction port. become.

Further, the cover 20b and flange 20c constituting the casing 20 of the vane pump ■P are pivotally supported by the transmission case 44 via bearings 41 and 42, respectively.

Spline engagement part 14 on rotor 19 of vane pump ■P
The second rotating shaft 14 connected via a has bearings 4 on both sides of the spline engagement portion 14a.
5.46, and are respectively pivotally supported by the cover 20b and the pre- and retainer 2Of.

Further, a ring-shaped spring 52.53 as a band-shaped spring is disposed at the cover 20b side end and the pressure retainer 2Of side end of the rotor 19, and this spring 52.53 is attached to the inner circumference of each vane 18. The vane 18 is brought into contact with the side base end portion of the inner peripheral surface 20d of the casing 20.
to bias.

As shown in FIG. 5, the ring-shaped springs 52 and 53 are slidably fitted into recesses 18a formed in each vane 18, and are either rigid or weakly elastic (endless thin strip-shaped). In the vane pump VP, which is made of spring steel (1) the amount of 97F of the vane 18 is small, the degree of deformation of this ring-shaped spring 52, 53 is small, and the function is achieved only by the tension of the spring, so even a linear one can be used. good.

In addition, numeral 43 in the figure $3 indicates a bearing that supports the first rotating shaft, 47 is a pulsation volume, 48 is an oil guide, 49 is a filter, 50 is a magnet, 51 is a bolt, and 54 is a Oil passages 55 each indicate a pulsation damper.

Since the vane pump of the present invention is configured as described above, when the vehicle is normally traveling straight, the effective radius of the tires of the front wheels 9 and the rear wheels 16 are the same, and the slip rotational speed of the tires is small, so that the four wheels are There is no rotational speed difference between the first rotating shaft 11 and the second rotating shaft 14 connected to the driving drive coupling device main body 13.

Therefore, no oil pressure is generated in the vane pump ~P, no driving force is transmitted to the rear wheels 16, and the front wheels are driven only by the front wheels 9.

However, in a state where the front wheels 9 normally slip within about 1% even if there is no large slip, such as when the vehicle accelerates straight ahead, the difference in rotational speed due to this is caused by the rotational speed difference between the first rotational shaft 11 and the second rotational shaft 14. When this occurs between the rotor 19 and the rotor 19, the vane pump
The and cam ring portion 20a rotate together, and a driving force corresponding to this oil pressure and the pressure receiving area of the vane is transmitted to the rear wheels 16, resulting in a four-wheel drive state.

In this case, the flow of oil in the vane pump ■P is caused by the relative rotation of the rotor 19 (see symbol A in Fig. 1), and the suction and discharge ports 23, 25, and 27 act as suction ports, and the check valve While oil is sucked in from the oil reservoir 30 via the oil reservoir 30 through the oil reservoir 30, the suction and discharge ports 22, 24.26 act as discharge ports, and at the same time close the check valve 29.31, the check valve 3
2. Oil is guided to the relief valve 33 via the oil passage 40.

In FIG. 1, solid line arrows indicate the flow of discharged oil, and broken line arrows indicate the flow of suction oil.

In this embodiment, in the relative rotation direction shown in FIG.
The first oil passage OL receives the discharge pressure P, but Fig. 4(,)
As shown in ~(d), this discharge pressure P3 includes the discharge pressures p, , p5 . p@ is superimposed and its pulsation is also superimposed, but the fluctuation value H2 of the pulsation is the discharge pressure P,, P5 . It is equal to the fluctuation value of the pulsation at P.

Further, a ring-shaped spring 52. Since S3 is provided, the vane 18 is always urged against the inner circumferential surface 20d of the cam ring portion 20a with a predetermined pressing force, and the driving force transmission characteristics of the vane pump ■v at the time of starting the engine 1 are improved. Ru.

At this time, the ring-shaped springs 52 and 53
While rotating together with the vane 8, it slightly slides inside the recess 18a of the vane 18.

Further, although the pressure receiving area on the discharge side of each suction and discharge port 22 to 27 is different for each boat, the second rotating shaft 14 is connected to the casing 20 through bushings (bearings) 45 and 46.
Even if an imbalance occurs in the radial force applied to the rotor tacho 9, the rotor 19 can be supported, and in this embodiment, the sum of the radial load vectors at the discharge port is The positions and sizes of the suction and discharge ports 22 to 27 and the cam ring portion 20a are adjusted so that
The shape of the inner peripheral surface 20d is determined.

Next, when the rotational speed of the front wheels 9 becomes very large compared to the rotational speed of the rear wheels 16, for example, when the front wheels slip on a snowy road, or when the rear wheels tend to lock up during sudden acceleration or braking, , the difference in open rotational speed between the first rotating shaft 11 and the second rotating shaft 14 connected to the four-wheel drive drive coupling device main body 13 becomes very large.

As a result, in the vane pump vP, an oil flow as shown in Fig. 1 occurs and a large hydraulic pressure is generated, but when a predetermined value is exceeded, the relief valve 33 resists the spring 34 and the opening discharge pressure remains almost constant. A four-wheel drive state is established in which a constant driving force corresponding to a constant discharge pressure is transmitted to the rear wheels 16.

Then, as the rotational speed of the front wheel 9 decreases, the rear wheel 1
6's rotational speed increases, reducing the rotational speed difference (
Same function as non-lip differential).

In this way, when the front wheels 9 are in a slip state, the drive torque to the rear wheels 16 is increased to avoid the situation where the vehicle cannot run, and when the rear wheels 16 are a little locked, the front wheels 9
The rear wheel 16 is prevented from locking by increasing the brake torque of the rear wheel 16.

On the other hand, when the rotational speed of the rear wheels 16 becomes very large compared to the rotational speed of the front wheels 9, for example, when the front wheels 9 are slightly locked in the braking state, the first A very large rotational speed difference occurs between the rotating shaft 11 and the second rotating shaft 14 in the opposite direction to that described above.

As a result, in the vane pump ■P, an oil flow occurs in the opposite direction to the oil flow shown in FIG.
．． 26 serves as a suction port, and oil is sucked in from the oil reservoir 30 through check valves 29, 29', while suction and discharge ports 23, 25, and 27 serve as discharge ports, passing through the check valve 28.29' and the first oil passage OL. 32 is closed, an extraordinary hydraulic pressure is applied which is led from the check valve 31 to the relief valve 33, but this hydraulic pressure is also kept constant by the relief valve 33, and a constant driving force is transmitted to the rear wheels 16, resulting in four-wheel drive. state.

Then, the brake torque to the rear wheels 16 is increased and the brake torque to the front wheels 9 is increased.
prevent locking.

Furthermore, during normal cornering, the rotational speed of the front wheels 9 is slightly higher than the rotational speed of the rear wheels 16, resulting in a four-wheel drive state in which brake torque is applied to the front wheels 9 and drive torque is applied to the rear wheels 16. A turning run is made.

As a result, by controlling the discharge pressure in the four-wheel drive drive coupling device main body 13 using the relief valve 33 so that it does not exceed a certain value, it is possible to eliminate the need for a four-wheel drive state in conventional part-time four-wheel drive vehicles. In this case, the driver's operation is now automatically switched between 4-wheel drive and 2-wheel drive. Wheel drive condition is obtained.

Furthermore, compared to a center differential that is always installed in conventional full-time four-wheel drive vehicles, this device can be made smaller and more compact, as well as reducing weight and cost.

Note that the number of vanes 18 in the embodiment may be 13, and in this case as well, the vanes 18 are arranged on the outer peripheral surface 19a of the rotor 19.
The holes 19b are opened at equal intervals.

Further, as shown in FIG. 6, in a modified example of the present invention, ten (or even eleven) vanes 18 are provided.
Six suction and discharge ports 22 to 27 are opened as in the above embodiment, and each port has a pressure receiving area A, , A2 . Forces F at A3, , F2. Each part of the casing 20 is set so that the resultant force of F is zero.

Even in this modification, substantially the same effects as in the embodiment can be obtained.

Note that the number Vn of vanes and the number Pn of a pair of suction ports and discharge ports in the embodiment and the modified example are merely examples.
The ratio (Vn/Pn) may be set to a non-integer multiple, that is, a real number multiple that is not an integral multiple.

As described above, according to the four-wheel drive drive coupling device equipped with the vane pump according to this embodiment, the following effects and advantages can be obtained with a simple configuration.

(1) Differential rotation between the front and rear wheels is allowed, which eliminates problems such as tight wheel braking in part-time four-wheel drive vehicles and the complexity of driving operations.

(2) Force is transmitted between the first rotating shaft and the $2 rotating shaft from the one rotating faster to the one rotating slower, so
This prevents one of the front wheels or the rear wheels from over-rotating, reliably preventing wheelspin, and contributing to vehicle safety.

(3) Compared to the center differential conventionally equipped in full-time four-wheel drive vehicles, it can be made smaller and lighter, and can also contribute to lower costs.

(4) Pulsations (fluctuations) in the discharge pressure in the first oil passage and the second oil passage on the discharge side are reduced and transmitted between the first rotation shaft and the second rotation shaft. This reduces torque fluctuations.

〔Effect of the invention〕

As detailed above, according to the vane pump of the present invention,
a casing connected to a first rotating shaft; a rotor connected to a second rotating shaft and housed in the casing;
a large number of vanes attached to the outer peripheral surface of the rotor and slidingly contacting the cam ring portion on the inner peripheral surface of the casing;
A vane biasing mechanism for biasing the large number of vanes toward the cam ring portion is provided, and the vane biasing mechanism includes a band-shaped or linear spring that abuts the base end portion of each of the large number of vanes on the inner circumferential side. This simple structure can reliably prevent oil leakage when the vane pump rotates at low speeds, improve the startability of the vane pump, and thereby improve driving force transmission performance.

[Brief explanation of the drawing]

Figures 1 to 6 show a four-wheel drive drive coupling device equipped with a vane pump as an embodiment of the present invention. Figure 1 is a cross-sectional view of this device, and Figure 2 shows a vehicle drive system. 3 is a longitudinal cross-sectional view of the device, and FIG. 4(a) to (
d) are all graphs showing the discharge pressure of the vane pump, FIG. 5 is a sectional view of the main parts thereof, FIG. Figure 8 shows a conventional vane pump with a pressure balanced fill spring type vane biasing mechanism; Figure 7 is its front view, and Figure 8 is its front view.
Figures 9 and 10 are sectional views taken along the vm-vm arrow in the figure, and Figures 9 and 10 show a conventional vane pump with a rocker arm type vane biasing mechanism, Figure 9 is its front view, and Figure 10 is its torsion coil spring. It is a front view. 1.Horizontal ennon, 2.Transmission, 3.Output shaft, 4
・・Drive gear (or 4-speed counter gear), 7...
Gear, 9...Front wheel, 10...Differential device, 11...First rotating shaft (outer shaft), 13...Four-wheel drive coupling device main body as a vane pump type coupling mechanism, 14...Second Axis of rotation(
inner shaft), 14a...spline engagement portion, 15. IS'
... Bevel gear mechanism, 16.. Rear wheel, 17.. Differential device, 18.. Vane, 18a.. Recess, 19.. Rotor.
19a...outer circumferential surface, 19b...hole, 20...casing, 20a...cam ring part, 20b...cover, 20
C...Flange, 20cl...Inner peripheral surface, 20e...Gear cam ring, 20[...Pressure retainer, 21...
Hydraulic circuit, 22-27...Suction and discharge port, 28, 29.2
9'...Check valve, 30...Oil reservoir, 33.32.
・Che. Relief valve, 33...Relief valve, 34...Spring, 35
・・Communication path, 36-38・・Pump chamber, 40・・Oil path,
41-43...Bearing, 44...Transmission case, 45.46...Bushing (bearing), 47...
・Pulsation volume, 4B...oil guide,
49... Filter, 50... Magnet, 51... Bolt, 52. 53... Ring-shaped spring as a strip spring, 54... Oil passage, 55... Pulsation damper, OLl... First oil passage, OL ,...2nd oilway, ■P.
・Vane pump. Agent Patent Attorney Yoshihiko Iinuma Figure 1 Figure 2 Figure 3 Figure 8 Figure 4 Figure 6 Figure 10

Claims (1)

[Claims] a casing connected to a first rotating shaft; a rotor connected to a second rotating shaft and housed in the casing;
a large number of vanes attached to the outer peripheral surface of the rotor and slidingly contacting the cam ring portion on the inner peripheral surface of the casing;
A vane biasing mechanism for biasing the large number of vanes toward the cam ring portion is provided, and the vane biasing mechanism includes a band-shaped or linear spring that abuts the base end portion of each of the large number of vanes on the inner circumferential side. A vane pump characterized by a structure 1&.