JPH0712644Y2 - Oil pump - Google Patents

Description

[Detailed Description of the Invention] [Industrial field of application] The present invention relates to an oil pump, and more specifically, to supply a part of lubricating oil from an oil pump discharge chamber to an oil seal provided around a shaft. Regarding oil pumps.

[Prior Art] As a conventional device of this type, for example, the Japanese Utility Model Laid-Open No. 62-13397
Some are disclosed in Japanese Patent Publication No. 7. This product introduces lubricating oil from the discharge chamber of the oil pump through the gap between the spigot part of the inner gear and the pump body into the oil seal chamber whose one end is sealed by the oil seal provided around the shaft to lubricate the oil seal. In addition, the lubricating oil is discharged at a position adjacent to the oil seal through a drain hole formed in the pump body by a pressure difference between the oil seal chamber internal pressure and the external pressure.

[Problems to be Solved by the Invention] However, in such a conventional oil pump, in order to reduce the axial length of the oil pump, the inner end portion of the oil seal is arranged facing the inlet of the drain hole. Therefore, if the cross-sectional area of the flow path of the drain hole is not sufficient and the discharge pressure of the oil pump rises, that is, the amount of oil supplied to the oil seal chamber increases, the pressure inside the oil seal chamber rises excessively. As a result, there is a problem that oil leaks from the oil seal and sometimes the oil seal is pulled out.

It is also possible to shorten the axial length of the oil seal so that it does not face the inlet of the drain hole in order to secure the flow passage cross-sectional area of the drain hole. Is insufficient, and rather helps to remove the oil seal.

The object of the present invention is to solve the conventional problems described above,
While enabling the axial length of the oil pump to be shortened, the oil seal state can be stably maintained and the oil seal can be maintained even if excessive lubrication oil is supplied to the oil seal chamber. It is to provide an oil pump that can prevent the oil from coming off.

[Means for Solving the Problems] In order to achieve the above object, the present invention communicates with an oil seal chamber that is formed between a pump body and a drive shaft and has one end closed with an oil seal. An oil pump having a radial drain hole formed in a body is characterized in that a notch is provided in a part of an outer periphery of the oil seal, and the notch and the drain hole are aligned with each other.

[Operation] According to the present invention, the drain hole is aligned with the notch formed in a part of the outer circumference of the oil seal. Then, the oil for lubrication is supplied from the discharge chamber of the pump to the oil seal chamber, and this is from the oil seal chamber through the notch,
It is discharged to the outside through a drain hole formed in the radial direction.
Therefore, the flow passage cross-sectional area of the drain hole is sufficiently secured, and even if the supply amount increases, the leakage from the oil seal and the oil seal can be prevented from coming off.

[Embodiment] An embodiment of the present invention will be specifically described below with reference to the drawings.

1 to 3 show an embodiment of the present invention. Here, 1 is a body case of the oil pump, 2 is a cover fixed to the body case 1 with countersunk screws, etc., and is driven by a crankshaft 3 in a pump chamber space formed by the body case 1 and the cover 2. An inner gear 4 and an outer gear 5 which is eccentrically and partially meshes with the inner gear 4 are rotatably housed in each other. Reference numeral 6 denotes an inlay portion formed to project from a side wall of the inner gear 4, and is supported by a bearing portion 7 formed in the body case 1 with a slight gap.

Further, 8 is an oil seal, the outer peripheral portion of which is press-fitted and fixed to the body case 1 so that oil leaking from the discharge chamber 12 through the gap between the spigot portion 6 of the inner gear 4 and the bearing portion 7 to the outside. The inner circumference is in sliding contact with the crankshaft 3 in order to prevent leakage. An oil seal chamber 9 is a space formed on the pump side of the oil seal 8. Reference numeral 10 denotes a drain hole bored in the radial direction of the body case 1 for returning the oil guided to the oil seal chamber 9 to an oil pan (not shown). Therefore, in this embodiment, in the oil pump configured as described above, in order to return the oil in the oil seal chamber 9 to the oil pan without blocking the drain hole 10 with the oil seal 8, a part of the outer circumference of the oil seal 8 is provided. A notch 11 is provided for alignment with the inlet of the drain hole 10.

In the present embodiment having the above-mentioned configuration, the pressurized oil in the discharge chamber 12 is the inlay portion 6 and the bearing portion 7 of the inner gear 4.
Is introduced into the oil seal chamber 9 through a gap between the oil seal chamber 9 and the oil seal chamber 9, and the notch provided in the oil seal chamber 9 at a part of the outer periphery of the oil seal 8
It is returned to the oil pan through 11 and the drain hole 10.

Therefore, the drain hole 10 that is bored in the radial direction ensures the maximum flow passage cross-sectional area without blocking the hole, and promotes the discharge of oil, while at the inner peripheral portion of the oil seal chamber 9. The pressure is reduced. As a result, the oil seal chamber 9
Even if the pressure acting on the sliding contact portion between the oil seal 8 located on the innermost side (center side) and the crankshaft 3 is reduced and the oil is excessively supplied to the oil seal chamber 9, Problems such as leakage from the oil seal 8 and falling off of the oil seal 8 as in the conventional case can be eliminated.

[Effects of the Invention] As is apparent from the above description, according to the present invention, the notch is provided in a part of the outer circumference of the oil seal, and the notch and the drain hole are aligned with each other. The flow passage cross-sectional area of the hole and the press-fitting margin of the oil seal can be sufficiently secured, and the axial length of the oil pump can be shortened, while preventing leakage from the oil seal or dropping of the oil seal. You can

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention, FIG. 2 is a view taken in the direction of arrow A in FIG. 1, and FIG. 3 is a side view showing an oil seal of the present invention. 1 …… Body case, 3 …… Crankshaft, 4 ……
Inner gear, 5 ... Outer gear, 6 ... Inlay part, 8
…… Oil seal, 9 …… Oil seal chamber, 10 …… Drain hole, 11 …… Notch.

Claims (1)

[Scope of utility model registration request] 1. An oil pump having a radial drain hole formed in the pump body, which communicates with an oil seal chamber which is formed between a pump body and a drive shaft and has one end closed by an oil seal. An oil pump characterized in that a notch is provided in a part of the outer periphery of the oil seal, and the notch and the drain hole are aligned with each other.