JPH0673387U - Oil pump - Google Patents

Abstract

(57) [Abstract] [Purpose] To improve workability by not requiring a pin to stop the liner from turning, and to shorten the total length of the pump to reduce its size. [Structure] By providing a liner 5 on the inner surface of the housing 2,
An outer rotor 3 having inner teeth 8 is rotatably accommodated in the liner 5, and an inner rotor 4 having outer teeth 9 meshing with the inner teeth 8 is eccentrically accommodated in the outer rotor 3 to accommodate the housing 2 and In the oil pump in which the drive shaft 13 is inserted into the through holes 10 and 11 that are eccentrically provided in the liner 5 so that the inner rotor 4 can be rotationally driven by the drive shaft 13, the oil pump is located outside the edge of the through hole 10 of the liner 5. An annular boss 20 is provided so as to project toward the boss 2
0 was press-fitted into the through hole 11 of the housing 2. Further, the bearing portion 14 of the drive shaft 13 is formed on the inner surface of the boss 20.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an oil pump applied to a shift control system of an automobile transmission.

[0002]

[Prior art]

 In this type of oil pump, weight reduction has recently been achieved by forming some of the members from aluminum. In the oil pump for automatic transmission shown in FIGS. 3 and 4, the housing 2 covered with the cover 1 is made of aluminum. The outer rotor 3 and the inner rotor 4 housed inside are made of Fe material instead of aluminum because of wear resistance. For this reason, an FC liner 5 made of the same material as the rotors 3 and 4 is provided on the inner surface of the housing 2 so that the aluminum housing 2 does not come into contact with and wear the rotors 3 and 4 made of Fe material. . The liner 5 is dish-shaped and press-fitted into the inner surface of the housing 2. Then, the inner peripheral surface and the inner bottom surface of the liner 5 are machined. As shown in FIG. 4, the housing 2 is provided with two detent pins 7 for engaging with the collar portion 6 provided on the outer peripheral edge of the liner 5 so as not to rotate.

The outer rotor 3 has internal teeth 8 and is housed inside the liner 5. Further, the inner rotor 4 has outer teeth 9 that mesh with the inner teeth 8 of the outer rotor 3, and is accommodated inside the outer rotor 3 eccentrically from the center O ₁ thereof by e. The liner 5 and the housing 2 are respectively formed with through holes 10 and 11 which are eccentric from the center O ₁ of the outer rotor 3 by e, and these through holes 10 and 11 are sleeve-shaped drive shafts that rotate integrally with the torque converter 12. 13 is inserted. When the drive shaft 13 is engaged with the inner rotor 4, the inner rotor 4 is rotationally driven by the rotation of the torque converter 4. The drive shaft 13 is supported by a bearing portion 14 provided on the inner surface of the through hole 11 of the housing 2. A chamber 16 sealed by an oil seal 15 is formed at a position adjacent to the bearing portion 14.

As shown in FIG. 4, the housing 2 has a suction port 18 that communicates with a plurality of pump chambers 17 on the right side of FIG. And a discharge port 19 communicating with the plurality of pump chambers 17 on the left side. In this oil pump, when the inner rotor 4 is rotationally driven and oil is sucked into the pump chamber 17 between the inner teeth 8 and the outer teeth 9 from the suction port 18, the oil is pumped as the inner rotor 4 rotates. When the volume of the chamber 17 changes, the chamber 17 is pressurized to a predetermined pressure and discharged from the discharge port 19. Oil leaking from the discharge side pump chamber 17 between the end surface of the inner rotor 4 and the liner 5 passes through between the drive shaft 13 and the bearing portion 14 of the housing 2 to lubricate the bearing portion 14. , Are stored in the chamber 16.

[0005]

[Problems to be solved by the device]

 However, in the above-mentioned conventional oil pump, since the pin 7 for stopping the rotation of the liner 5 has to be provided as described above, the number of parts is increased, and the hole for the pin 7 and the mounting of the pin 7 are required. However, there was a problem that the number of man-hours of work increased. Further, the total axial length of the pump becomes longer by the thickness of the bottom of the liner 5, the gap S between the pump housing and the converter housing 2 becomes smaller, and the torque converter 12 is eccentrically shaken when the torque converter 12 rotates. There was a case where 12 contacted the pump housing 2 and generated noise or was damaged. The present invention has been made in view of the above problems, and it is an object of the present invention to provide an oil pump that does not require a pin for locking a liner and has good workability, and an oil pump that has a short total length and can be downsized. It is intended.

[0006]

[Means for Solving the Problems]

 In the oil pump according to the present invention, a liner is provided on the inner surface of a housing to rotatably accommodate an outer rotor having internal teeth in the liner, and the inner rotor has internal teeth. In an oil pump that eccentrically accommodates an inner rotor having outer teeth that mesh with, and inserts a drive shaft into a through hole that is eccentrically provided in the housing and liner, and is capable of rotationally driving the inner rotor by the drive shaft. An annular boss is provided so as to project outward from the edge of the through hole of the liner, and the boss is press-fitted into the through hole of the housing. In another oil pump according to the present invention, the bearing portion of the drive shaft is formed on the inner surface of the boss of the liner of the oil pump.

[0007]

【Example】

 Next, an embodiment of the present invention will be described with reference to the accompanying drawings. 1 and 2 show an oil pump according to the present invention, which is the same as the conventional oil pump shown in FIGS. 3 and 4 except that a boss 20 is provided on the liner 5, and the corresponding portions are the same. The reference numeral is attached. The boss 20 of the liner 5 is provided so as to project axially outward from the peripheral edge of the through hole 10 of the liner 5. The outer peripheral surface of the boss 20 is press-fitted into the through hole 11 of the housing 2, and the bearing portion 14 of the drive shaft 13 is formed on the inner peripheral surface of the boss 20. The axial length of the boss 20 is long enough to secure a sufficient bearing portion 14.

In the oil pump of this embodiment, the boss 20 of the liner 5 is eccentric with respect to the center O _{1 of the} liner 5 by e as shown in FIG. 2, so that the liner 5 is press-fitted into the housing 2. In this case, the liner 5 only fits with respect to the housing 2 at a predetermined angular position in the direction of rotation. Therefore, even if the liner 5 is not rotated by the pin 7 as in the conventional case, it does not shift in the circumferential direction at the time of machining in the circumferential direction, so that the working can be performed normally. Therefore, the rotation stop pin 7 is not required, and the hole processing and pin mounting work for the pin 7 are eliminated, and further, the positioning is not required when the liner 5 is press-fitted.

Further, since the bearing portion 14 is formed on the inner surface of the boss 20 of the liner 5, it is not necessary to provide the housing 2 with excess thickness for the bearing portion as in the conventional case, and the total length of the pump is shortened. . This will be specifically described. In the conventional oil pump shown in FIG. 3, the thickness of the rotors 3 and 4 is t _r , the thickness of the bottom of the liner 5 is t _l , and the length of the bearing portion 14 is l ₁ . Assuming that the length of the chamber 16 is l ₂ , the total length L of the oil pump is the sum of these, that is, L = t _r + t _l + l ₁ + l ₂ . On the other hand, the total length L of the oil pump of this embodiment is L = t _r + l ₁ + l ₂ , which is shortened by the wall thickness t _l of the bottom of the liner 5. Therefore, it is possible to secure a wide gap S between the pump housing 2 and the torque converter 12. It is also possible to reduce the overall length of the transmission and reduce the size of the transmission.

[0010]

[Effect of device]

 As is clear from the above description, according to the invention of claim 1, since the liner is provided with the eccentric boss that is press-fitted into the through hole of the housing, the rotation stop pin of the liner becomes unnecessary, and the number of parts is reduced. In addition, machining of rotation stop pin holes and pin installation work are not required, and positioning when pressing the liner into the housing is not required, improving assembly workability. Further, according to the invention of claim 2, since the bearing portion of the drive shaft is provided on the boss of the liner, the total length of the pump can be shortened and the transmission can be miniaturized.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an oil pump according to the present invention.

FIG. 2 is a front view of a liner.

FIG. 3 is a vertical sectional view of a conventional oil pump.

FIG. 4 is a front view of the oil pump shown in FIG. 2 with a cover removed.

[Explanation of symbols]

2 ... Housing, 3 ... Outer rotor, 4
… Inner rotor, 5… Liner, 8… Inner teeth,
9 ... External teeth, 10, 11 ... Through hole,
13 ... drive shaft, 20 ... boss.

Claims (2)

[Scope of utility model registration request] 1. A liner is provided on an inner surface of a housing to rotatably accommodate an outer rotor having internal teeth in the liner, and an inner rotor having external teeth meshing with the inner teeth is biased in the outer rotor. An oil pump in which a drive shaft is inserted through a through hole provided eccentrically in the housing and the liner so that the inner rotor can be rotationally driven by the drive shaft, the drive shaft being located outside the edge of the through hole of the liner. An oil pump characterized in that a ring-shaped boss is provided so as to project toward the through hole of the housing. 2. The oil pump according to claim 1, wherein a bearing portion of the drive shaft is formed on an inner surface of the boss.