JP2526682Y2 - Oil pump device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an improvement in an oil pump device that prevents an increase in pressure in an oil seal chamber.

[Problems to be Solved by Related Art and Invention] Conventionally, as an oil pump device provided in an engine, for example, one disclosed in Japanese Utility Model Publication No. 56-24245 is known.

In this oil pump device, a drive shaft such as a crankshaft is inserted into a rotor housing provided on one side of a crankcase via an oil seal, and an inner rotor fixed to the drive shaft and the inner rotor are provided. An outer rotor meshing with the rotor is housed in the rotor housing and closed by a lid.

An oil seal chamber is formed inside the oil seal along the outer periphery of the drive shaft, and the oil seal chamber and the inside of the crankcase are communicated via a passage. As the oil pump device is operated, oil is supplied to the oil seal chamber from between the inner rotor and the rotor housing, and the pressure between the supplied oil and the seal between the oil seal and the drive shaft. Sex has been enhanced. Then, the oil is returned into the crankcase through the passage.

However, the cross-sectional area of the passage is often limited by the outer shape of the oil pump, the length of the drive shaft, and the like. Therefore, the oil that has reached the oil seal chamber gradually increases in pressure as the oil pump device operates. Is raised, and there is a possibility that the oil leaks from the portion where the oil seal is engaged to the outside of the crankcase.

To cope with this, for example, Japanese Patent Publication No. 56-27685 discloses that the oil seal chamber and the inside of the crankcase are communicated with each other by, for example, a groove formed on a surface in contact with the drive of the inner rotor, and A technique has been proposed in which the reached oil is returned into the crankcase through the groove.

However, in this prior art, the formation of the groove not only reduces the contact area between the inner rotor and the shaft that drives the inner rotor, but also causes stress concentration in the relief passage. There is a possibility that the joint between the inner rotor and the inner rotor drive shaft, that is, the strength of the oil pump drive system is reduced.

[Purpose of the invention] The present invention has been made in view of these circumstances.
It is an object of the present invention to provide an oil pump device capable of preventing an increase in the pressure of an oil seal chamber and preventing a decrease in the strength of an oil pump drive system.

[Means and Actions for Solving the Problems] The oil pump device according to the present invention includes an inner rotor fixed to a drive shaft and an outer rotor meshed with the inner rotor in a rotor housing provided on one side of a crankcase. In the oil pump device provided with an oil seal chamber in the rotor housing, an oil release passage communicating the oil seal chamber with the inside of the crankcase is provided. And is formed obliquely with respect to the direction of the axis of the drive shaft.

With this configuration, oil leaking into the oil seal chamber is directed to the inner rotor into the crankcase via an oil escape passage that is formed so that the oil seal chamber side is directed in the rotation direction of the inner rotor and that is obliquely formed with respect to the axis of the drive shaft. By returning, the pressure inside the oil seal chamber is prevented from rising more than necessary.

Hereinafter, an embodiment of the oil pump device according to the present invention will be described with reference to the drawings.

1 to 3 relate to an embodiment of the present invention. FIG. 1 is a side view of an oil pump device, FIG. 2 is a front view of a rotor, and FIG. 3 is a side view of an inner rotor.

In these figures, reference numeral 1 denotes a crankcase, and 2 denotes an oil pan fixed to a lower portion of the crankcase 1 and storing a predetermined amount of oil.

A bearing hole 3 is formed on one side of the crankcase 1, and a drive shaft 4 such as an engine crankshaft is rotatably supported via a bearing 3 a engaged with the bearing hole 3. ing. Further, a recess 6 concentric with the bearing hole 3 is formed outside the crankcase 1.

The recess 6 accommodates a rotor 7 including an inner rotor 7a fixed to the drive shaft 4 and an eccentric outer rotor 7b meshed with the inner rotor 7a.
When the drive shaft 4 is rotated, a suction portion and a discharge portion are formed between the inner rotor a and the outer rotor 7b.

The recess 6 is closed by a lid 8 in a state in which the rotor 7 is housed, and the recess 6 and the lid 8 constitute a rotor housing 9.

A hole having substantially the same diameter as the bearing hole 3 is formed in the center of the lid 8.
The drive shaft 4 protrudes outside the crankcase 1 through the hole 8a. An oil seal 11 is interposed between the outermost side of the hole 8a and the drive shaft 4.

The space provided between the oil seal 11 and the inner rotor 7a is set as an oil seal chamber 12, and when the rotor 7 is rotated, the space between the lid 8 and the inner rotor 7a is reduced. Oil is supplied to the oil seal chamber 12. And the oil seal chamber
The lip portion 11a of the oil seal 11 is pressed against the drive shaft 4 by the pressure of the oil supplied to the oil seal 12, so that the airtightness is improved.

An oil release passage 13 communicating with the inside of the bearing hole 3 is formed in a portion of the inner rotor 7a exposed to the oil seal chamber 12.

Oil escape passage 13 drilled in the inner rotor 7a
Has no effect on the joint between the drive shaft 4 and the inner rotor 7a, so that the drive shaft 4 and the inner rotor 7a
, That is, the oil pump drive system is not reduced in strength.

As shown in FIGS. 2 and 3, the oil release passage 13 is provided between the oil seal chamber 12 and the rotor 7 and the drive shaft 4.
It is formed obliquely oriented in the direction of rotation. Therefore, as the inner rotor 7a rotates, the oil in the oil seal chamber 12 actively flows into the escape passage 13 and returns to the inside of the crankcase 1 through the bearing hole 13. The oil release passage 13
Means that even if oil escapes from this oil escape passage 13,
The diameter is formed such that the pressure inside the oil seal chamber 12 is always constant.

On the other hand, the rotor housing 9 has a suction port 16 and a discharge port corresponding to a suction portion and a discharge portion of the rotor 7.
17 are formed. The suction port 16 communicates with a strainer 19 immersed in the oil of the oil pan 2 via a suction passage 18 formed in the crankcase 1, while the discharge port 17 communicates via an oil gallery (not shown). It communicates with the lubrication-required parts provided in each part of the engine.

 Next, the operation of the embodiment having the above configuration will be described.

When the drive shaft 4 is rotated, the inner rotor 7a fixed to the drive shaft and the outer rotor 7b meshed with the inner rotor 7a are rotated, and the inner rotor 7a and the outer rotor 7b are rotated between the inner rotor 7a and the outer rotor 7b. A suction unit and a discharge unit are configured. Then, a negative pressure is generated on the suction port 16 side, and the oil in the oil pan 2 is discharged by the strainer 19 and the suction passage 1.
The oil flows into the suction port 16 via 8, and the oil is discharged to the discharge port 17 and supplied to the lubrication-required parts of each part of the engine. On the other hand, since the rotor 7 is rotated in the rotor housing 9, a slight gap is provided between the rotor 7 and the rotor housing 9. Therefore, oil is continuously supplied to the oil seal chamber 12 from the discharge port 17 having a relatively high pressure through the gap. This oil is supplied to the lip 11 of the oil seal chamber 11.
a that presses a to the drive shaft 4.
If the pressure in the oil seal 12 rises more than necessary, oil leaks from the space between the lip portion 11a and the drive shaft 4 to the outside of the crankcase 1.

In the present invention, the inner rotor 7a is provided with an oil escape passage.
Drilling 13 prevents oil from leaking outside.

That is, since the oil release passage 13 is formed such that the oil seal chamber 12 side is oriented in the rotation direction of the inner rotor 7a, when the inner rotor 7a is rotated, the oil in the oil seal chamber 12 is released from the oil release chamber. Positively flows into the passage 13. The oil that has flowed into the oil escape passage 13 is pressed by another oil that flows in later by the rotation of the inner rotor 7a, and a centrifugal force due to the rotation of the inner rotor 7a is applied. Under pressure, the oil flows out of the opening opposite to the oil seal chamber 12 into the bearing hole 3. After lubricating the bearing 3a engaged with the bearing hole 3, the crankcase 1
The oil flows into the oil pan 2 and is returned to the oil pan 2 by dropping in the crankcase 1.

When the rotation of the drive shaft 4 is increased, the amount of oil supplied to the oil seal chamber 12 is increased with the increase of the rotation. Since the amount returned to the oil pan 2 is also increased, the pressure of the oil in the oil seal chamber 12 is always kept constant.

In general, while the rotor 7 is rotating, pulsating pressure is constantly generated in the crankcase 1. However, in this embodiment, the oil pressure is reduced by the oil release passage.
Because it is configured to be raised when passing 13
This has the effect that the outflow of oil from the oil seal chamber 12 is less affected by the pulsation pressure.

Further, in this embodiment, since the bearing 3a is configured to be lubricated with the oil that escapes through the oil escape passage corrugation 13, there is no need to provide an oil gallery at this portion.

[Effects of the Invention] As described above, in the oil pump device according to the present invention, the oil release passage is formed so that the oil seal chamber side is directed in the rotation direction of the inner rotor, and the oil seal chamber is rotated when the inner rotor is rotated. Of the oil supplied to the oil seal chamber is prevented from unnecessarily increasing, and the strength of the oil pump drive system is prevented from being reduced. This has the effect of being possible.

[Brief description of the drawings]

1 to 3 relate to an embodiment of the present invention, FIG. 1 is a side view of an oil pump device, FIG. 2 is a front view of a rotor,
FIG. 3 is a side view of the inner rotor. 1 ... Crankcase 4 ... Drive shaft 7a ... Inner rotor 7b ... Outer rotor 9 ... Rotor housing 11 ... Oil seal 2 ... Oil seal chamber 13 ... Oil escape passage

Claims (1)

(57) [Scope of request for utility model registration] An inner rotor fixed to a drive shaft and an outer rotor meshed with the inner rotor are housed in a rotor housing provided on one side of a crankcase, and an oil seal chamber is provided in the rotor housing. In the oil pump device provided with, the oil release passage communicating the oil seal chamber and the inside of the crankcase, the oil seal chamber side to the inner rotor is directed in the rotation direction of the inner rotor and in the axial direction of the drive shaft. An oil pump device characterized by being obliquely drilled.