JPS60228784A - Vane pump - Google Patents

Abstract

PURPOSE:To minimize the effect of pulsated oil pressure occurring inside the oil passages connected to the oil discharge ones among pairs of oil discharge and suction ports by determining the number of the vanes of a vane pump to the number by a factor of fractional numbers greater than the total number of the suction and the discharge ports. CONSTITUTION:Pairs of suction and discharge ports 22-27 via which working oil is induced and discharged into and from a plurality of pump casings are formed in this vane pump. Primary oil passages OL1 which are connected to either the suction or the discharge ports when a rotor and a casing make relative turn and secondary oil passages OL2 which are connected to the rest ports are also formed in said vane pump. To reduce the effect of pulsated oil pressure occurring inside those oil passages, the number of the vanes 18 is determined to the number by a factor of fractional numbers greater than the total number of the suction and the discharge ports. Since pulsation of discharged oil may be reduced, a transmission torque of a transmission shaft may be prevented from being fluctuated.

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 speaking, in 4-wheel drive (4WD) vehicles where the front and rear wheels are driven by the same engine, there may be some difference in the effective radius of the front and rear tires, or the rolling path of the wheels when turning. What are the differences between tires?
4) Since an unreasonable force is applied to the drive system, it is necessary to provide a means to prevent this.

For this reason, conventionally, in full-time four-wheel drive vehicles, even if there is a difference in rotational speed 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, the drive A differential device called a center differential is used to transmit power, and it is disadvantageous compared to part-time 4-wheel drive vehicles in terms of weight, size, and cost, and because it has a differential rotational force capacity. There are cases where four-wheel drive cannot be achieved even when wheel drive is required, 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 installed, 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.

In a four-wheel drive drive coupling device equipped with such a vane pump type coupling mechanism, each pump is formed as a vane pump or a pressure-balanced vane pump as shown in Figure 6. A pair of suction and discharge ports c, d, and eJ for sucking and discharging hydraulic fluid into each of chambers a+b are arranged in an even number (hereinafter referred to as "number of boats PnJ"), and the rotor g and casing h are arranged in a predetermined number. Direction (6th
(see reference numeral A in the figure), the suction and discharge ports C and e on the discharge side are connected by the first oil passage OL, and the suction and discharge ports ele on the suction side are connected to the second oil passage OL. They are connected by a path OL2.

[Problem that the invention seeks to solve]

However, in such a conventional vane pump, the number Vn of vanes 1 is set to an even number, and the number Vn (here, 10) of vanes is equal to the number of boats Pn (here, 2).
), and the discharge pressure P, , P2 from each suction and discharge port c, e:d+f on the discharge side [Figure 7(b)
, reference numeral H1 in (C) occur simultaneously in terms of phase, the hydraulic pressure Po with increased hydraulic pulsation [Fig. 7 (,)
Refer to reference numeral H6] occurs in the first oil passage OL.

The present invention aims to solve these problems, and provides a vane pump that can reduce hydraulic pulsations in oil passages connected to each of the suction and discharge ports on the discharge side. The purpose is to

[Means for solving problems]

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. It is equipped with a large number of vanes that are in sliding contact with the cam ring part on the inner peripheral surface of the casing, and a plurality of pump chambers that are formed by being surrounded by the rotor, casing, and vanes, and each of these plurality of pump chambers is filled with hydraulic oil. A first oil passage is formed with a pair of suction and discharge ports for sucking and discharging the fluid, and is connected to one of the suction side and the discharge side of each of the suction and discharge ports during relative rotation between the rotor and the casing; A second oil passage connected to the other side is provided, and these first oil passage and the second oil passage are provided.
In order to reduce hydraulic pulsation in the oil passage, the number of vanes is set to a non-integral multiple (that is, a non-integral multiple) of the number of the pair of suction and discharge ports.

[For production]

With the above configuration, the phases of the discharge pressures from the respective discharge sides of the plurality of suction and discharge ports are different from each other, and hydraulic pulsations in the first oil passage and the second oil passage are reduced.

〔Example〕

Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
1 to 50 show a four-wheel drive drive coupling device equipped with a vane pump as an embodiment of the present invention, FIG. 1 is a cross-sectional view of this device, and FIG. 2 shows a vehicle drive system. A schematic configuration diagram, Fig. 3 is a vertical cross-sectional view of this device, and Fig. 4 (, ) to (
d) is a graph showing the discharge pressure of the vane pump, and FIG. 5 is a cross-sectional view of a modification of the present device shown in correspondence with FIG.

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, which serves as a vane pump type coupling mechanism.

The gear cam ring 20e rotates the casing 20 and connects to the first rotating shaft (
differential gear 1 for the front wheels 9 from the gear 7 via the outer shaft) 11
The driving force is transmitted to the front wheels 9 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. is 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 15, 15' that changes the direction of rotation.
to drive.

As shown in Figures @1 and 3, this four-wheel drive drive coupling device main body 13 is composed of a vane pump VP as a hydraulic pump (hydraulic coupling mechanism) and a hydraulic circuit 21 attached thereto. The rotor 19 of the VP 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.

In the vane pump VP as a hydraulic pump, a large number (14 holes in this case) of holes 19b are formed at equal intervals in the circumferential direction on the outer circumferential surface 19a of the rotor 19, and each of the large number of holes 19b is 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.

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 VP discharges an amount of oil proportional to its rotation speed, and the vane pump VP discharges an amount of oil proportional to its rotation speed.
When relative rotation occurs between the first rotating shaft 1'1 and the second rotating shaft 14, it functions as a hydraulic pump and generates hydraulic pressure.

Discharge port of vane pump vP (suction/discharge ports 22 to 27 at the tip of the vane 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 part 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 side in the rotational direction and the discharge port when located on the distal side, are formed at approximately 120° intervals, and each is formed at approximately 120° intervals. The suction/discharge ports 22, 24, 26 and the suction/discharge ports 23+25+27, spaced apart by 120 degrees, have 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 and 29', respectively, and from the oil reservoir 30 to each oil passage OL, OL
Only the flow to the first oil path OL is allowed.

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

OF2 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 the flange 20c that constitute the casing 20 of the vane pump vP are each pivotally supported by the transmission case 44 via bearings 41 and 42.

Spline engagement portion 14 on rotor 19 of vane pump vP
The second rotating shaft 14 connected via a has bushings (bearings) 45 on both sides of the spline engagement portion 14a.
．． The cover 201) and the pressure retainer 2Of are respectively pivotally supported via 46.

Furthermore, a ring-shaped spring 5 is provided at the end of the rotor 19 on the cover 20b side and on the pressure retainer 2Of side.
2.53 is arranged, and this spring 52°53
pushes each vane 18 one inch toward the inner circumferential surface 20d of the casing 20.

In addition, the reference numeral 43 in FIG. 3 indicates a bearing that supports the first rotating shaft1), 47 is a pulsation volume, 48 is an oil guide, 49 is a filter, 50 is a magnet 7, and 51 is a bearing. A bolt, 54 indicates an oil passage, and 55 indicates 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 difference in rotational speed between the first rotating shaft 11 and the second rotating shaft 14 connected to the driving drive coupling device main body 13.

Therefore, the vane pump VP does not generate oil pressure,
No driving force is transmitted to the rear wheels 16, and only the front wheels 9 drive the front wheels.

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 happens, the vane pump VP functions to generate oil pressure according to this rotational speed difference, and the rotor
and the cam ring portion 20a rotate as one, 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 VP is caused by the relative rotation of the rotor 19 (see symbol A in FIG. 1), and the suction and discharge ports 23+2'5. While oil is sucked in from the oil reservoir 30 through the oil reservoir 30, the suction and discharge ports 22, 24.26 act as discharge ports, closing the check valves 29.31 and simultaneously closing the check valves 32.31. Oil is guided to the relief valve 331 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 P3, but as shown in Fig. 4 (,)
As shown in ~(d), the discharge pressures P, , P, and P6 of the respective suction and discharge ports 22, 24, and 26 are superimposed on this discharge pressure P, and the pulsation thereof is also superimposed, but the pulsation is The fluctuation value I(2 is equal to the fluctuation value of pulsation at the discharge pressure P, , P7.P6.

Further, since the ring-shaped springs 52 and 53 are provided, the vane 18 is always connected to the inner circumferential surface of the cam ring portion 20a.
By being energized to 0d, the driving force transmission characteristics of the vane pump ■P at the time of starting the engine 1 are improved.

Furthermore, although the pressure receiving area on the discharge side of each of the suction and discharge ports 22 to 27 is different for each port, 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 19, the rotor 19 can be supported. The positions and sizes of the suction and discharge ports 22 to 27 and the cam ring portion 20a are adjusted so that the sum becomes zero.
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 rotational speed difference between the first rotating shaft 11 connected to the four-wheel drive drive coupling device main body 13 and the @2 rotating shaft 14 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 opens against the spring 34 and the 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 front wheel 90 rotation speed decreases, the rear wheel 1
6's rotational speed increases, reducing the rotational speed difference (
Same function as non-slip differential).

In this way, when the front wheels 9 are in a slip state, the drive torque to the rear wheels 16 is increased, making it impossible to drive, and when the rear wheels 16 are a little locked, the brake torque of the front wheels 9 is increased. This prevents the rear wheel 16 from collapsing.

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 VP, an oil flow occurs in the opposite direction to the oil flow shown in Fig. 1, and the suction and discharge ports 22 and 24
．． 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, 25.27 serve as discharge ports and pass through the first oil path OL to the check valve 28. 32 is closed, a large hydraulic pressure is applied from the check valve 32 to the relief valve 33. 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 driving torque is applied to the rear wheels 16. A turning run is made.

In this way, by controlling the discharge pressure in the 4-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 control the discharge pressure in the 4-wheel drive drive coupling device main body 13 so that it does not exceed a certain value. Previously, the driver's operation was required, but now the system automatically switches between 4-wheel drive and 2-wheel drive, and the 4-wheel drive system uses driving force according to the difference in rotational speed between the front wheels 9 and rear wheels 16. A driving state is obtained.

Additionally, 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, and it also reduces weight and costs.

In addition, the number of vanes 18 in the embodiment may be 13, and in this case also, the vanes 18 are located on the outer peripheral surface 19a of the rotor 19.
The holes 19b are opened at equal intervals.

Further, as shown in FIG. 5, 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 boat 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 F3 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 multiple of a real number 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 the present 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 corner braking of part-time four-wheel drive vehicles and the complexity of driving operations.

(2) Force is transmitted between the first rotating shaft and the second 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) It can be made smaller and lighter than the center differential conventionally equipped on full-time four-wheel drive vehicles, and can also contribute to lower costs.

〔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 plurality of pump chambers are formed by being surrounded by the rotor, a casing, and a vane, and a pair of suction and discharge ports for sucking and discharging hydraulic oil are formed in each of the plurality of pump chambers. a first oil passage connected to one of the suction side and the discharge side of each of the suction and discharge ports during relative rotation between the rotor and the casing;
A second oil passage connected to the other side is provided, and in order to reduce hydraulic pulsations in the first oil passage and the second oil passage, the number of the vanes is a non-integral multiple of the number of the pair of suction and discharge ports. (In other words, a multiple that is not an integer multiple) has a simple structure that reduces the pulsation (fluctuation) of the discharge pressure in the discharge side of the first oil passage and the second oil passage.
Fluctuations in the torque transmitted between the rotating shaft and the second rotating shaft are reduced.

[Brief explanation of drawings]

Figures 1 to 5 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 (, ) to (
d) is a graph showing the discharge pressure of the vane pump, FIG. 5 is a cross-sectional view of a modified example of the device shown in correspondence with FIG. 1, and FIGS. 6 and 7 are graphs showing the conventional vane pump. , FIG. 6 is a cross-sectional view thereof, and FIGS. 7(,) to (c) are graphs showing its effect. 1. Horizontal engine, 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 part, 15.15'...
・Bevel gear mechanism, 16... Rear wheel, 17... Differential device,
18...Vane, 19...Rotor, 19a...Outer peripheral surface,
19b...Hole, 20...Casing, 20a...Cam ring, 20b--Cover, 20c...7 Runno, 2
0d...Inner peripheral surface, 20e...Gear cam ring, 2Of...
・Pressure retainer, 21...Hydraulic circuit, 22-27
・・Suction/discharge port, 28, 29.29' ・・Check valve, 30・・Oil reservoir, 31.32・・・Check 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, 48... Oil guide, 49... Filter, 50... Magnet, 51... Bolt, 52.
53...Ring-shaped spring, 54...Oil L55...Pulsation damper, OL,...1st oil path, 0I-2.
・Second oil path, vP...vane pump. Agent Patent Attorney Yoshihiko Iinuma Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 -

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 plurality of pump chambers are formed by being surrounded by the rotor, a casing, and a vane, and a pair of suction and discharge ports for sucking and discharging hydraulic oil are formed in each of the plurality of pump chambers. a first oil passage connected to one of the suction side and the discharge side of each of the suction and discharge ports during relative rotation between the rotor and the casing;
A second oil passage connected to the other side is provided, and in order to reduce hydraulic pulsations in the first oil passage and the second oil passage, the number of the vanes is a non-integral multiple of the number of the pair of suction and discharge ports. A vane pump characterized by being set to.