JPH0552285U - Internal gear type oil pump - Google Patents

Abstract

(57) [Summary] [Purpose] Even if excessive pressure is applied to the inside of the oil seal, it prevents the oil seal from slipping out of the sealing surface of the sealing recess. [Structure] An outer rotor 3 having inner teeth rotatably accommodated in a recess 1A formed in a casing 1, an inner rotor 2 having outer teeth meshing with the inner teeth of the outer rotor 3, and a drive for rotating the inner rotor 2. In the internal gear type oil pump including the shaft 5, the groove portion 1C is formed on the sealing surface of the sealing recess 1B provided in the casing 1 for supporting the drive shaft 5 and press-fitting the oil seal 9.

Description

[Detailed description of the device]

[0001]

[Industrial application]

 The present invention relates to an internal gear type oil pump which is particularly suitable for use as a lubricating oil supply for automobile engines.

[0002]

[Prior Art]

 As a conventional internal gear type oil pump, for example, the one disclosed in Japanese Utility Model Laid-Open No. 63-78182 is known.

In this oil pump, by rotating a drive gear (inner rotor) and a driven gear (outer rotor) that mesh with each other in a recess formed in a casing that constitutes the pump housing, the oil pump is driven from a suction port formed in the recess. It is an internal gear type oil pump that absorbs oil, supplies oil into the meshing volume, conveys and discharges oil to the discharge port, and performs pumping action.

Then, a casing for supporting the drive shaft for applying a rotational force to the inner rotor is formed with a sealing recess for press-fitting an oil seal to support the drive shaft, and the oil seal is provided in the sealing recess. It prevents the oil that is press-fitted and leaks from the contact surface between the drive shaft and the inner rotor from flowing out.

[0005]

[Problems to be solved by the device]

 However, in the internal gear type oil pump having such a conventional structure, the oil seal inserted to prevent the oil from flowing out to the sealing recess is fixed only by press fitting. If excessive pressure is applied, the oil seal may slip out of the sealing recess provided in the casing.

An object of the present invention is to solve the problems caused by the conventional structure and to prevent the oil seal from being pulled out from the sealing recess even if an excessive pressure is applied to the sealing recess inside the oil seal. An object is to provide a contact gear type oil pump.

[0007]

[Means for Solving the Problems]

 To achieve this object, the present invention provides an outer rotor rotatably housed in a recess formed in a casing and having inner teeth, an inner rotor having outer teeth meshing with the inner teeth of the outer rotor, In an internal gear type oil pump including a drive shaft that engages with an inner rotor to rotate the inner rotor, and a sealing recess provided in the drive shaft supporting surface of the casing, a sealing surface of the sealing recess is provided. The groove is formed so that the oil seal can be caught.

[0008]

[Action]

 According to the present invention, since the groove is formed so that the oil seal can be caught on the sealing surface of the sealing recess, the rubber material around the oil seal enters the inside of this sealing recess after the oil seal is pressed into the sealing recess. The engagement between the oil seal surface and the oil seal surface becomes strong. Therefore, even if an excessive pressure is applied to the sealing recess inside the oil seal, the oil seal does not come out of the sealing recess.

[0009]

【Example】

 An internal gear type oil pump according to the present invention will be described below with reference to the embodiments shown in the drawings.

In the drawing, reference numeral 1 denotes a casing, and an outer rotor 3 having inner teeth and a inner rotor 2 having outer teeth meshing with inner teeth of the outer rotor 3 are freely rotatable in a recess 1 A formed in the casing 1. It is housed in. The inner rotor 2 and the outer rotor 3 housed in the recess 1A have a structure covered by a cover 4 fastened to one side of the casing 1 with bolts or the like, and engage with the fitting hole 2A of the inner rotor 2. The inner rotor 2 is rotationally driven by the drive shaft 5.

A sealing recess 1B is formed in the casing 1 on the spigot coupling side of the inner rotor 2 on the outer periphery of the drive shaft 5, and an oil seal 9 is press-fitted into the sealing surface of the sealing recess 1B. The sealing recess 1B into which the oil seal 9 is press-fitted is provided in the casing 1 on the spigot joint side of the inner rotor 2. However, the spigot joint part has an oil leak due to its structure. A drain hole 10 is provided to release the back pressure of the sealing recess 1B surrounded by 9.

However, even if the drain hole 10 is provided, an excessive pressure may be applied to the inside of the oil seal 9, which prevents the oil seal 9 from slipping out of the sealing recess 1B. In, the groove portion 1C is formed on the sealing surface of the sealing recess 1B. Therefore, when the oil seal 9 is press-fitted into the sealing recess 1B, the rubber material on the outer periphery of the oil seal 9 rides on the groove 1C and the drain hole 10 and is caught and prevented from coming off.

Although there is no particular limitation on the position and shape of the groove 1C, the position where the rubber material around the oil seal 9 can be caught, for example, as shown in FIG. 2, the oil seal 9 has a drain hole. Since it is also caught by 10, it suffices to provide it on at least the drive shaft 5 on the sealing surface of the sealing recess 1B on the side opposite to the drain hole 10. As a result, the catch of the oil seal 9 with respect to the sealing recess 1B is secured vertically with respect to the drive shaft 5, so that the oil seal 9 is prevented from slipping out of the sealing recess 1B.

In the present invention having the above-described configuration, the teeth of the inner rotor 2 and the outer rotor 3 gradually increase in volume after the meshing volume becomes zero at the maximum meshing position X as the drive shaft 5 rotates. Then, the oil sucked from the suction port 6 is sucked into the volume chamber 8. The oil having the maximum volume at the closed position Y is supplied to the engine through the discharge port 7, but oil leaks from the spigot joint portion of the inner rotor 2 and excessive pressure is applied to the inside of the oil seal 9. Even if it does, the rubber material on the outer periphery of the oil seal 9 will not be caught in the groove 1C and the drain hole 10, and the oil seal 9 will not come out from the sealing recess 1B.

[0015]

[Effect of the device]

 As described above with reference to the embodiments shown in the drawings, according to the internal gear type oil pump of the present invention, the groove portion 1C is formed on the seal surface of the sealing recess 1B provided in the casing 1. Therefore, even if an excessive pressure is applied to the inside of the oil seal 9, it is possible to prevent the rubber material on the outer periphery of the oil seal 9 from being caught in the groove 1C and the drain hole 10 and the oil seal 9 from coming off.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

[Explanation of symbols]

 1 Casing 1A Recess 1B Seal Recess 1C Groove 2 Inner Rotor 2A Fitting Hole 3 Outer Rotor 4 Cover 5 Drive Shaft 6 Suction Port 7 Discharge Port 9 Oil Seal

Claims (1)

[Scope of utility model registration request] 1. An outer rotor rotatably housed in a recess formed in a casing and having inner teeth, an inner rotor having outer teeth meshing with inner teeth of the outer rotor, and an inner rotor engaged with the inner rotor to rotate the inner rotor. An internal gear type oil pump comprising: a drive shaft to be driven; and a sealing recess provided on the drive shaft supporting surface of the casing, wherein a groove is formed so that an oil seal can be caught on the sealing surface of the sealing recess. An internal gear type oil pump characterized by: