JPH0315832Y2 - - Google Patents

Description

[Detailed explanation of the idea]

[Industrial Field of Application] This invention relates to an oil pump, particularly an oil pump built into an automatic transmission used in a vehicle such as an automobile. [Prior Art] Conventionally, oil pumps built into automobile transmissions have been described, for example, in Japanese Patent Application Laid-open No. 115483/1983, and the present applicant has also disclosed in U.S. Pat.
The application has been filed under No. 112594 etc. This type of oil pump has been applied for registration as a utility model, and its structure will be explained in detail with reference to the drawings. FIGS. 5 and 6 show an example of a variable displacement vane pump 1, and an example will be described in which the variable displacement vane pump 1 is built into an automatic transmission and used to supply hydraulic fluid thereto. That is, the variable displacement vane pump 1 includes a housing 4 that includes a cover 2 that houses a torque converter (not shown), and a flange 3a provided on a hollow fixed shaft 3 that is fixed to the cover 2. A storage section 5 is formed therein, and the device is stored in this storage section 5. An input shaft (not shown) of a transmission provided on the right side in FIG. 1 is inserted into the fixed shaft 3, and the output of the torque converter is transmitted to the transmission via the input shaft. It's becoming like that. The variable displacement vane pump 1 has a rotor 10 that is rotatably fitted around the outer periphery of the fixed shaft 3, and the rotor 10 is formed with a plurality of slits 11 that extend in the radial direction and are open to the outside. A vane 12 is slidably fitted into the slit 11, and the outer diameter end of the vane 12 protrudes radially from the outer periphery of the rotor 10. A space S serving as a pump chamber is provided on the outer periphery of the rotor 10, and an annular cam ring 13 is fitted therein, and the inner periphery 13a of the cam ring 13 and the rotor 10 are arranged eccentrically. The tip of the vane 12 comes into sliding contact with the circumference 13a. Further, a locking groove 14 is formed on the inner periphery of the rotor 10, and the locking groove 14 is rotatably fitted onto the outer periphery of the fixed shaft 3 and connected to a pump impeller (not shown) of the torque converter. The end of the drive shaft 6 is locked. Therefore, the rotor 10 is driven by rotation of a crankshaft (not shown) via the drive shaft 6 and the pump impeller. On the other hand, the cam ring 13 has one end (right side in Fig. 2).
is rotatably attached to the cover 2 via a pin 15, and an arm 16 is provided protruding from the other end (left side in FIG. 2) of the cam ring 13.
The cam ring 13 is urged in an upward rotation direction about the pin 15 by a compression spring 17 disposed between the cam ring 6 and the cover 2 . Further, an operating rod 31 that is moved in the axial direction (vertical direction in the figure) by an actuator 30 attached to the cover 2 in opposition to the urging force of the compression spring 17 is brought into contact with the upper side of the arm portion 16. The cam ring 13 is rotated by the movement of the operating rod 31, and the amount of eccentricity between the cam ring 13 and the rotor 10 is changed. The actuator 30 is operated by the discharge pressure of the pump 1, and rotates the cam ring 13 upward (in the X direction) by reducing the pressing force of the operating rod 21 in the low rotation range of the engine. The cam ring 13 is rotated downward (in the Y direction) by increasing the pump discharge amount per 10 rotations of the rotor, and by increasing the pressing force of the operating rod 31 in the high rotation range of the engine. rotor 10
The pump discharge amount relative to rotation is reduced. Incidentally, a suction port 18 and a discharge port 19 are formed opposite to each other on the inner periphery 13a of one side surface (right side in FIG. 1) of the cam ring 13. The hydraulic fluid introduced into the space S is pressurized by the rotation of the vanes 12 together with the rotor 10, and flows from the discharge port 19 provided on the opposite side to the inside of the torque converter and the control valve of the automobile transmission. supply is increasing. Reference numerals 20 and 21 denote side plates that are housings that are closely arranged on both sides of the rotor 10 and the cam ring 13, and these side plates 20 and 21 maintain a liquid-tight function in the space S. There is. Also, 22,2
3 is an annular groove 1 formed on both sides of the rotor 13;
Vane rings 0a and 10b are arranged concentrically with the cam ring 13, and the bail rings 22,
23 is in sliding contact with the inner diameter end of the vane 12 and
The outer diameter end of the cam ring 13 is guided so that it is brought into close contact with the inner periphery 13a of the cam ring 13. Suction port 1 is provided on one side of the cam ring 13.
8. An annular lubrication groove 10 on the outer diameter of the discharge port 19
0 is formed. [Problems to be Solved by the Invention] However, in such conventional oil pumps, a side plate is disposed on the part of the housing on which pump elements such as the rotor and cam ring slide, and the side plate is placed on the housing side. Since this prevents wear, there was a problem that the number of parts increased. If this side plate is removed, the housing will be made of aluminum alloy such as JIS ADC12, and the rotor, cam ring, etc. will be made of Fe-C-Ni.
-Since it is made of Cu-based sintered alloy, there was a problem that the housing was easily worn out. [Means for Solving the Problems] This invention was made by paying attention to the problems of the conventional art, and it uses ceramic fibers at least in the abutting parts of the rotor, cam ring, etc. of the aluminum alloy housing of the oil pump. The aim is to solve the above problems by dispersing the [Function] In the oil pump of the present invention, ceramic fibers are dispersed in the sliding parts of the oil pump's aluminum alloy housing with the rotor, cam ring, etc., so the ceramic fibers reduce the amount of wear on the housing. act. [Embodiment] FIG. 1 is a diagram showing an embodiment of this invention. First, to explain the configuration, 13 is a cam ring,
10 is a rotor, and 12 is a vane, which are housed in the housing 4. The sliding part 4a of the housing 4 on which the cam ring 13, rotor 10 and vane 12 come into contact and slide is made of JIS ADC12 alloy (Cu: 1.8wt%, Si: 11wt%, Mg: 0.2wt%,
Zn: 0.8wt%, Fe: 1.2wt% Balance: Substantially A)
It is composed of a layer in which ceramic fibers 41 are dispersed in a base. As shown in FIG. 2, the fibers 41 are two-dimensionally randomly oriented on the sliding portion 4a of the housing 4 or parallel to the sliding portion. Further, a layer in which ceramic fibers 42 were dispersed was also formed on the peripheral portion 4b of the housing 4. The fibers 42 are two-dimensionally randomly oriented on the cylindrical surface forming the peripheral portion 4b. Details regarding the fibers used in the examples below are provided in the table. Note that the orientation of the fibers 41 is determined by adjusting the orientation of the fibers 41 in the sliding portion 4a.
The tests were also carried out on the vertical position. (Example 1A')

[Table] Next, in carrying out the present invention, a method of manufacturing the housing will be described. Figure 3 51, 52
and 53 are molds for forming the housing 4, and 54 is a plunger. Said fiber 4
A molded body 55 obtained by suction molding 1 and 42 according to a conventional method is inserted into a cavity 56 of a mold, the molten ADC12 alloy 57 is poured into the mold, and a plunger 54 is used to mold the molded product at 800 kg/cm ^{2 .} It was solidified while being pressurized. Next, the molds 51, 52, and 53 were opened, and the housing rough material was knocked out using the knockout pin 58, and machined to form the housing 4, which was subjected to the following evaluation. For comparison, a housing was created without any fibers. Next, the evaluation results of these housings will be explained. Cam ring, rotor, vane (material: C: 0.2wt%, Ni: 2wt%, Cu:
It contained 0.5wt% (balance: essentially Fe), etc., and was incorporated into an automatic transmission for motoring evaluation. The evaluation conditions were a durability test of 100 cycles (total of 100 hours), where one cycle was 650 rpm x 30 minutes → 4000 rpm x 30 minutes (total of 1 hour). During this time, the oil temperature was 140-145℃ and the pump discharge pressure was 8
Controlled at Kg/ ^cm2 . As a result, it can be seen in FIG. 4 that wear of the housing is significantly reduced by dispersing ceramic fibers in the housing 4 (Examples 1A, 2, and 3). By dispersing the fibers, the coefficient of thermal expansion of the surrounding area approaches the coefficient of thermal expansion of materials such as cam ring material and rotor material, which reduces play during operation (Table 2) and further reduces wear on the housing. (Example 1B, 1C), when the fiber orientation is perpendicular (Example 1A')
This caused the rotor material to wear out, and the abrasion powder also caused the housing to wear out. However, the amount of wear is less than conventional products that do not contain any fibers.

[Table] ** Average coefficient of thermal expansion of cam ring and rotor material ~
14.2× ¹⁰⁻⁶
−
[Effect] As explained above, according to this invention,
By dispersing ceramic fibers in the sliding parts of the aluminum alloy housing and the rotor, etc., the wear resistance of the oil pump housing is improved. As a result of the coefficient of expansion approaching the coefficient of thermal expansion of the rotor material, cam ring material, etc., it is possible to reduce backlash during operation and to significantly reduce wear on the housing.

[Brief explanation of drawings]

Fig. 1 is a sectional view showing an embodiment of a variable displacement vane pump, which is an oil pump of the present invention, Fig. 2 is an enlarged view of the main part of Fig. 1, and Fig. 3 is a housing of the oil pump of the present invention. Figure 4 is a cross-sectional view of the mold used for manufacturing, Figure 4 is a diagram showing the durability test results of the housing and rollers used in the oil pump of the present invention, Figure 5 is a cross-sectional view of a conventional variable displacement vane pump, and Figure 6 is a cross-sectional view of a conventional variable displacement vane pump.
The figure is a sectional view taken along the line -- in FIG. 1... Variable displacement vane pump, 4... Housing, 4a... Sliding part, 4b... Peripheral part, 5...
Storage unit, 10... Rotor, 12... Vane, 13
...Cam ring, 18...Intake port, 19...
Discharge port, 41, 42... Ceramic fiber.

Claims (1)

[Scope of utility model registration request] In an oil pump equipped with an oil pump housing made of an aluminum alloy, ceramic fibers are dispersed in the aluminum alloy matrix at least in the sliding parts of the oil pump housing where pump elements such as the rotor and cam ring come into contact and slide. An oil pump characterized by having a layer.