JP2846340B2 - Variable displacement vane oil pump - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a variable displacement vane oil pump adapted to an automatic transmission for an automobile or the like.

(Conventional technology) Conventionally, as a variable displacement vane oil pump adapted to an automatic transmission, for example, "NISSAN full range electronically controlled automatic transmission maintenance manual RE4R01
Pumps described in "Types" on page I-76 are known.

As shown in FIG. 6, this conventional pump comprises a rotor 02 provided on a rotary drive shaft 01, a plurality of vanes 03 supported on the rotor 02 so as to be movable in a radial direction, and an outer periphery of the vane 03. A cam ring 04 having a vane sliding contact cylindrical surface 04a whose surface is in sliding contact with the vane sliding contact cylindrical surface 04a and being movably supported within the pump housing 05 within a predetermined range in which the center of the vane sliding contact cylindrical surface 04a is eccentric from the center of the rotor 02; A pump that covers one side surface of the rotor 02, the vane 03, and the cam ring 04 and has a pump cover (not shown) in which a suction port hole 06 and a discharge port hole 07 are formed is known.

(Problems to be Solved by the Invention) However, in such a conventional variable displacement vane oil pump, the discharge port hole 07 of the pump cover is not provided.
A groove called a triangular notch 08 extends the start end of the discharge port hole 07 so that the oil trapped at the top dead center flows out to the discharge port hole 07 little by little when the pump operates. Since the groove was formed such that the flow path cross-sectional area was gradually enlarged as approaching the discharge port hole 07, the following problems were posed.

Triangle notch 08 is for vane 03, cam ring 04, rotor
02, When the oil chamber surrounded by the pump housing 05 and the pump cover shifts from the suction port hole 06 side to the discharge port hole 07 side, the oil chamber is fully opened when the vane 03 passes through the start end of the discharge port hole 07. It is provided for the purpose of preventing the oil pressure from fluctuating abruptly and preventing the hydraulic vibration generated due to the oil pressure fluctuation from adversely affecting noise and the like.

When processing the triangle notch 08 on the pump cover,
Since it is necessary to gradually reduce the depth of the groove toward the tip, it is difficult to obtain dimensional accuracy at the position of the notch tip.

Further, it is difficult to improve the dimensional accuracy when the triangular notch 08 is to be implemented together with the pump holes 06 and 07 using a mold.

That is, in any case, it is difficult for the triangular notch 08 to have the dimensional accuracy determined by the design.

Since the triangular notch 08 is formed in a stationary pump casing member such as a pump cover and a pump housing together with the respective port holes 06 and 07, the triangular notch 08 cannot follow the change of the top dead center due to the eccentricity of the cam ring 02, The function of suppressing the increase in hydraulic pressure is not effectively exerted at all eccentric positions of the cam ring.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and is intended to provide a triangular notch function that easily achieves dimensional accuracy and suppresses abrupt oil pressure fluctuations effectively at all eccentric positions of a cam ring. It is an object of the present invention to develop a variable displacement vane oil pump capable of achieving both a triangular notch function and a lubrication function while providing a hydraulic adjustment groove and a lubrication groove on the same cam ring.

(Means for Solving the Problems) In order to solve the above problems, a variable displacement vane oil pump according to the present invention includes a rotor provided on a rotary drive shaft,
The rotor has a plurality of vanes movably supported in a radial direction, and a vane sliding cylindrical surface with which the outer peripheral surface of the vane slides. The center of the vane sliding cylindrical surface is eccentric from the center of the rotor. A cam ring movably supported in a predetermined range, a pump casing member covering the rotor, vane and cam ring and having a suction port hole and a discharge port hole formed therein; a discharge pressure groove portion and a lubrication groove portion provided on the cam ring; And a lubricating groove for supplying lubricating oil using discharge pressure on a sliding surface with a pump casing member, wherein the cam ring has a vane sliding contact cylindrical surface. Of these, at least a position where the start end of the discharge port hole is extended is provided with a hydraulic adjustment groove for suppressing a sudden change in hydraulic pressure. A narrow than the radial width of the section, and, width also a constant groove depth, the connection point between the discharge groove portion and the lubricating groove of the lubricating grooves,
The means is set at a position between the start point of the hydraulic pressure adjustment groove and the start point of the discharge port opening.

(Operation) When the pump is operating, suck oil through the suction port hole,
The chamber surrounded by vanes, cam rings, etc. is filled with oil, and while this oil chamber moves from the suction port hole side to the discharge port side after passing through the top dead center, it is pumped by the chamber volume change, and the discharge port hole Pressurized oil is sent out.

In the operation of the pump, when the oil chamber surrounded by vanes or the like shifts from the suction port hole side to the discharge port hole side after passing through the top dead center, at least a position where the starting end of the discharge port hole is extended is adjusted to a hydraulic pressure. Since the groove is provided, when the vane is at the position of the oil pressure adjusting groove, an oil pressure adjusting operation for maintaining the oil pressure balance by communicating the adjacent oil chambers is performed.

By this hydraulic pressure adjusting operation, a sudden change in hydraulic pressure due to the full opening of the oil chamber when the vane passes through the start end of the discharge port hole is suppressed.

In addition, the hydraulic adjustment groove has a width smaller than the radial width of the discharge port opening, so that the conventional triangular notch function can be exerted. There is no need for groove processing for gradually changing the road cross-sectional area, groove processing at a constant depth is sufficient, and dimensional accuracy can be easily obtained.

Furthermore, since the hydraulic adjustment groove is provided on the cam ring that determines the amount of eccentricity, it follows the change of the top dead center due to the eccentric position, and the triangular notch function can be exerted at all eccentric positions.

In addition, the connection point between the discharge pressure groove and the lubrication groove of the lubrication groove is set at a position between the start point of the hydraulic adjustment groove and the start point of the discharge port opening. A high pressure is maintained, and a triangular notch function for suppressing a sudden change in hydraulic pressure caused by the hydraulic pressure adjusting groove and a lubricating function for supplying lubricating oil to the lubricating groove portion using the discharge pressure of the lubricating groove can be achieved.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

 First, the configuration will be described.

FIGS. 1 and 2 show a variable displacement vane oil pump according to a first embodiment, in which a rotary drive shaft 1 is provided with a rotor 2 provided by spline coupling, and the rotor 2 is movably supported in a radial direction. The pump housing 5 includes a plurality of vanes 3 and a vane sliding contact cylindrical surface 4a on which the outer peripheral surface of the vane 3 slides. The center of the vane sliding contact cylindrical surface 4a is eccentric from the center of the rotor 2 within a predetermined range. And a pump cover 8 which covers one side of the rotor 2, the vane 3 and the cam ring 4 and has a suction port hole 6 and a discharge port hole 7 formed therein.

The rotary drive shaft 1 extends from a pump of a torque converter, and a transmission case cover 9 and a transmission input shaft 10 are provided inside the rotary drive shaft 1.
Are concentrically arranged.

The rotor 2 has a radially formed vane groove 2a for mounting the vane 3, and a vane ring 11 for defining an inner position of the vane 3.

One end of the cam ring 4 is supported by the pump housing 5 by a pivot pin 12, and a return spring 13 is provided at the other end to urge the cam ring 4 in an eccentric direction.
Is controlled by the hydraulic control of an oil chamber 16 formed above the control piston 15 supported by the pivot pin 14 in the drawing.

Further, the cam ring 4 is provided with lubrication grooves 4d, 4e on each sliding side surface 4b, 4c of the pump housing 5 and the pump cover 8 in order to ensure smooth sliding during the eccentric operation of the cam ring 4. ing.

And, in the vane sliding cylindrical surface 4a of the cam ring 4, a position extending the starting end of the discharge port hole 7,
A lubrication groove 4e provided on the sliding side surface 4c on the pump cover 8 side.
And a discharge-side hydraulic pressure adjusting groove 17 is provided.

 Next, the operation will be described.

When the rotary drive shaft 1 applies a driving force to the rotor 2 and operates the pump in a state where the cam ring 4 is eccentric, oil is sucked from the suction port hole 6 and the vane 3, the cam ring 4,
A chamber surrounded by the rotor 2, the pump housing 5 and the pump cover 6 is filled with oil, and the oil chamber is shifted from the suction port hole 6 side to the discharge port hole 7 side after passing through the top dead center. Under the action of the pump, pressure oil is sent out from the discharge port hole 7.

During the operation of the pump, the oil chamber surrounded by the vane 3 or the like passes through the top dead center from the suction port hole 6 side and reaches the discharge port hole 7.
When the vane 3 is located at the position of the discharge-side oil pressure adjusting groove 17, the adjacent oil is adjusted when the vane 3 is at the position of the discharge-side oil pressure adjusting groove 17. The chambers (for example, the chambers A and B in FIG. 1) are communicated to maintain a hydraulic balance, that is, a hydraulic pressure adjusting operation for lowering the hydraulic pressure level on the high pressure side is performed.

Due to this hydraulic pressure adjusting action, when the vane 3 passes through the starting end of the discharge port hole 7, the oil pressure on the discharge port hole 7 side is reduced, and a sudden change in the oil pressure as in the case where the oil chamber is fully opened at once is suppressed. Thus, adverse effects on noise caused by hydraulic vibration are prevented.

That is, the triangular notch function described in the related art is achieved by the discharge-side hydraulic pressure adjusting groove 17 provided in the cam ring 4.

As described above, in the variable displacement vane oil pump according to the first embodiment, the following effects can be obtained.

Unlike the triangular notch, the discharge-side hydraulic pressure adjusting groove 17 does not need to gradually change the cross-sectional area of the flow path, and can be formed with a groove having a constant depth, so that dimensional accuracy can be easily obtained.

Since the discharge-side hydraulic pressure adjusting groove 17 is provided on the cam ring 4 for determining the amount of eccentricity, the position of the discharge-side hydraulic pressure adjusting groove 17 follows a change in the top dead center due to the eccentric position, and a triangle that suppresses a sudden change in hydraulic pressure. The notch function can be effectively exerted at all eccentric positions.

The discharge side hydraulic adjustment groove 17 is provided on the sliding side of the pump cover 8 side.
Since the lubrication groove 4e provided in 4c is provided in an extended relationship, the discharge-side hydraulic adjustment groove 17 is formed at the same time when the lubrication groove 4e is machined.
Can be processed, and the number of processing steps and processing costs are hardly increased.

Next, a description will be given of a variable displacement vane oil pump according to a second embodiment shown in FIG.

The pump of the second embodiment is an example in which the pump of the first embodiment is provided with only the discharge-side hydraulic adjustment groove 17 as a hydraulic adjustment groove. This is an example in which a hydraulic pressure adjusting groove 18 is provided.

Therefore, in the second embodiment, since the suction-side oil pressure adjusting groove 18 is provided, the oil pressure fluctuation when closing and closing the suction port hole 6 with the vane 3 can be suppressed, and the oil pressure fluctuation higher than that of the first embodiment pump. The suppression effect is obtained.

Note that the other configuration and operation and effect are the same as those in the first embodiment, and thus description thereof will be omitted.

As described above, the embodiments have been described based on the drawings. However, the specific configuration is not limited to the embodiments, and even if there is a design change or the like without departing from the gist of the present invention, it is included in the present invention. .

For example, in the embodiment, the example in which the hydraulic pressure adjusting grooves 17 and 18 are provided in the sliding side surface 4c on the pump cover 8 side of the vane sliding contact cylindrical surface 4a of the cam ring 4 is shown in FIG. Thus, the hydraulic pressure adjusting grooves 17, 18 may be provided at the center of the vane sliding cylindrical surface 4a of the cam ring 4, or the hydraulic pressure adjusting grooves 17, 18 may be provided as shown in FIG. The sliding contact cylindrical surface 4a may be provided on the sliding side surface 4b on the pump housing 5 side.

(Effect of the Invention) As described above, in the variable displacement vane oil pump according to the present invention, at least the start end portion of the discharge port hole is extended from the cylindrical surface of the cam ring that slides against the vane. The hydraulic adjustment groove is provided with a groove width smaller than the radial width of the discharge port opening, and has a constant width and depth. Since the connection point with the lubrication groove is set at the position between the start point of the hydraulic pressure adjustment groove and the start point of the discharge port opening, it is easy to obtain dimensional accuracy and all cam rings have a triangular notch function that suppresses sudden oil pressure fluctuations. And the lubrication function can be achieved at the same time while the oil pressure adjustment groove and the lubrication groove are provided in the same cam ring.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a variable displacement vane oil pump according to a first embodiment of the present invention, FIG. 2 is a sectional view of a cam ring taken along line II of FIG. 1, and FIG. FIGS. 4 and 5 are sectional views showing another example of a position where a hydraulic pressure adjusting groove is provided, and FIG. 6 is a sectional view showing a conventional variable displacement vane oil pump. . DESCRIPTION OF SYMBOLS 1 ... Drive rotary shaft 2 ... Rotor 3 ... Vane 4 ... Cam ring 4a ... Vane sliding contact cylindrical surface 5 ... Pump housing 6 ... Suction port hole 7 ... Discharge port hole 8 ... Pump cover 17 ... Discharge side hydraulic adjustment groove 18 ... Suction side Hydraulic adjustment groove

──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Atsushi Kobayashi 700-1, Kamoda, Imaizumi, Fuji-shi, Shizuoka Prefecture Inside Japan Automatic Transmission Co., Ltd. (72) Inventor Kazuo Oguri 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Mazda Co., Ltd. (56) References JP-A-60-155787 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) F04C 15/04 321

Claims (1)

(57) [Claims] 1. A rotor provided on a rotary drive shaft, and a plurality of vanes movably supported by the rotor in a radial direction.
The outer peripheral surface of the vane has a vane sliding contact cylindrical surface in sliding contact,
A cam ring movably supported in a predetermined range in which the center of the vane sliding contact cylindrical surface is eccentric from the center of the rotor;
A pump casing member that covers the rotor, vane and cam ring and has a suction port hole and a discharge port hole formed therein; a discharge pressure groove portion and a lubrication groove portion provided in the cam ring; A variable displacement vane oil pump having a lubrication groove for supplying lubricating oil using a discharge pressure, wherein at least a start end of a discharge port hole of a vane sliding contact cylindrical surface of the cam ring is extended. A hydraulic adjustment groove for suppressing a sudden change in hydraulic pressure is provided at the position, the hydraulic adjustment groove having a width smaller than the radial width of the discharge port opening and having a constant width and depth; A variable displacement vane oil pump, wherein a connection point between a discharge pressure groove portion and a lubrication groove portion of a groove is set at a position between a start point of a hydraulic adjustment groove and a start point of a discharge port opening.