JPH03290075A - Oil pump device - Google Patents

Abstract

PURPOSE:To improve the lubrication effect between a bearing hole and a driving shaft by opening an oil passage communicating to a suction passage on a bearing hole on a pump cover which rotatably supports the driving shaft, in the constitution in which an inner rotor and outer rotor are arranged in a rotor accommodation chamber. CONSTITUTION:When a driving shaft 3 of an oil pump device revolves, the revolution of the driving shaft 3 is transmitted to an inner rotor 4 through a knock pin 5, and transmitted from the outer gear 4B of the inner rotor 4 to the inner gear 5A of an outer rotor 5, and the outer rotor 5 is synchronously revolved. Oil is sucked from a suction passage 6A into a suction space in which a gap between the inner gear 5A of the outer rotor 5 and the outer gear 4B of the inner rotor 4 spreads, and the oil is discharged through a discharge passage 6B from a discharge space in which the gap contracts. In this case, an oil passage 20 is provided for the communication between a bearing hole 2B on a pump cover 2 and a suction passage 6A. Accordingly, oil is introduced into the oil passage 20 by the pressure lowering in an intake space, and the lubrication between the driving shaft 3 and the bearing hole 2B is carried out.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention comprises an inner rotor that rotates integrally with a drive shaft and has external teeth, and an inner rotor that is eccentric around the inner rotor and has internal teeth on the outer teeth of the inner rotor. An outer rotor with internal teeth to be implanted is placed in a rotor storage chamber formed in the pump case, and a suction space and a discharge space formed by the external teeth of the inner rotor and the internal teeth of the outer rotor are connected to the pump. The present invention relates to an oil pump device that is connected to a suction passage and a discharge passage formed in a cover.

[Conventional technology]

A conventional oil pump device will be explained with reference to FIG.

1 has a connecting flat surface IA on the left side in FIG.
This is a pump case in which a rotor storage chamber IB having a circular cross section is opened in the connecting flat surface IA, and a bearing hole IC is connected and bored at the bottom of the rotor storage chamber IB.

Reference numeral 2 designates a pump cover having a connecting flat surface 2A corresponding to the connecting flat surface LA of the pump case 1, and also having a bearing hole 2B drilled coaxially with the axis of the bearing hole IC of the pump case 1. .

Then, the bearing hole IC of the pump case 1 and the pump cover 2
A drive shaft 3 is rotatably inserted into the bearing hole 2B, and a rotational force is applied to one end of the rotary shaft 3 from a drive source (not shown).

On the other hand, the drive shaft 3 that passes through the rotor storage chamber 1B has
The inner rotor 4 is fitted into the drive shaft 3 so as to rotate together with the drive shaft 3.

Specifically, this is achieved by fitting a knock pin 5 protruding from the drive shaft 3 into a coupling groove 4A provided at the center of the inner rotor 4.

On the outer periphery of the inner rotor 4, an annular outer tooth 4B is formed concentrically with the longitudinal axis of the drive shaft 3. The outer rotor 5 has an annular inner tooth 5A and is arranged eccentrically around the inner rotor 4, and the outer teeth 4B of the inner rotor 4 and the inner teeth 5A of the outer rotor 5 mesh with each other and roll. , the inner rotor 4, and the outer rotor 5 are arranged in the rotor storage chamber IB.

And if the internal teeth 5A and external teeth 4B are trochoidal curves,
The internal teeth 5A and the external teeth 4B are joined at their peaks and valleys in some parts, and their peaks are joined in other parts. Further, an arc-shaped suction passage 6A and a discharge passage 6B are opened in the connecting flat surface 2A of the pump cover 2, and by joining the pump force /^-2 and the pump case l, the suction passage 6A and the discharge passage 6B opens into the rotor storage chamber 1B of the pump case l, and further opens into the suction passage 6.
A is connected to an oil inlet (not shown), and the discharge passage 6B is connected to an oil outlet (not shown).

When the inner rotor 4 rotates, the gap between the outer teeth 4B of the inner rotor 4 and the inner teeth 5A of the outer rotor 5 expands to form a suction space for sucking oil, and this suction space is used as a suction space. On the other hand, a discharge space for discharging oil is formed at a portion where the gap between the outer teeth 4B of the inner rotor 4 and the inner teeth 5A of the outer rotor 5 is reduced.
This discharge space opens into the discharge passage 6B. Note that S refers to the oil seal storage hole 1D that opens outward from the end of the bearing hole 1C of the pump case 1 (to the right in FIG. 1st
These oil seals are respectively arranged in oil seal storage holes 2C that open toward the left side in the figure.

Further, a suction passage corresponding groove 7A and a discharge passage corresponding groove 7B having shapes corresponding to the suction passage 6A and the discharge passage 6B are bored in the bottom of the rotor storage chamber IB, and the suction passage corresponding groove 7A is formed by an oil seal S. It is connected to the oil seal storage hole A on the divided rotor storage chamber IB side (left side in FIG. 1) by a communication path 8.

In this oil pump device, when the drive shaft 3 rotates, the rotation of the drive shaft 3 is transmitted to the inner rotor 4 via the knock pin 5, and this rotation is transmitted from the outer teeth 4B of the inner rotor 4 to the inner teeth 5A of the outer rotor 5. It is transmitted and rotates the outer rotor 5 synchronously.

According to this, oil is sucked from the suction passage 6A into the suction space where the gap between the internal teeth 5A of the outer rotor 5 and the external teeth 4B of the inner rotor 4 is enlarged, and the oil is sucked into the internal 5A of the outer rotor 5.
Oil is discharged through the discharge passage 6B from the discharge space in which the gap between the outer teeth 4B of the inner rotor 4 and the outer teeth 4B of the inner rotor 4 is reduced, thereby achieving a pumping action.

On the other hand, considering the lubrication of the bearing part, regarding the bearing hole 1C of the pump case 1, during the suction process of the oil pump, the oil sucked into the suction passage corresponding groove 7A is
The oil flows into the oil seal storage hole A on the rotor storage chamber IB side divided by the oil seal S through the communication path 8, and this oil enters the bearing hole 1C to lubricate the drive shaft 3 and the bearing hole IC. Intimidate.

Also, regarding the bearing hole 2B of the pump cover 2, the drive shaft 3
A gap of, for example, about 0.3 mm is formed between the outer periphery of the bearing hole 2B and the bearing hole 2B, and this gap prevents an increase in contact surface pressure between the bearing hole 2B and the outer periphery of the drive shaft 3.

[Problem to be solved by the invention]

In such conventional oil pump devices, when applying rotational force from the drive source to the drive shaft 3, a method is often adopted in which a gear is integrally arranged on the drive shaft 3 and the gear of the drive source meshes with this gear. However, the axial center of the gear of the drive shaft 3 and the gear of the drive source may be perpendicular or inclined.

According to this, the drive shaft 3 is subjected to a force that is inclined with respect to the longitudinal axis direction of the drive shaft 3 supported by the bearing hole 2B and the IC, and at this time, the bearing hole 2B of the pump cover 2 and the drive shaft It is not desirable that there is a gap between the two.

That is, the end of the drive shaft 3 may swing due to the gap, and the local surface pressure between the bearing hole 2B and the drive shaft 3 may increase, or the outer teeth 4B of the inner rotor 4 and the inner part of the outer rotor 5 may The local surface pressure with tooth 5A increases,
This is because the local surface pressure between the outer circumference of the outer rotor 5 and the inner wall of the rotor storage chamber IB increases.

Furthermore, it is not preferable when the output is extracted from the other end of the drive shaft on the opposite side to the one end of the drive shaft 3 that receives the rotational force.

[Means to solve problems]

The oil pump device of the present invention is intended to solve the above-mentioned problems, and in particular reduces the gap between the bearing hole on the pump case side and the bearing portion of the drive shaft, and improves the lubrication of the bearing portion. In particular, in order to achieve the above object, an inner rotor is fitted onto a drive shaft rotatably supported by a pump case and a pump cover covering the pump case, rotates integrally with the drive shaft, and is provided with external teeth: an outer rotor that is eccentric around the inner rotor and has internal teeth that mesh with the external teeth of the inner rotor; external teeth,
An oil pump device comprising a suction space and a discharge space formed by internal teeth of an outer rotor; a pump cover having a suction passage connected to the suction space and a discharge passage connected to the discharge space; and a drive shaft that is rotatable. An oil passage connected to the suction passage is opened in the bearing hole of the pump cover supported by the pump.

A part of the oil sucked into the suction passage is supplied to the bearing hole of the pump cover through the oil passage, thereby providing a lubricating effect between the bearing hole and the drive shaft.

〔Example〕

Hereinafter, one embodiment of the oil pump device according to the present invention will be described with reference to Fig. 2. (Those having the same structure as those in FIG. 1 will be designated by the same reference numerals and their descriptions will be omitted.) Reference numeral 20 indicates a bearing hole 2B and a suction passage 6A provided in the pump cover 2.
This is the oil passage that connects the and.

The oil passage 20 shown by the solid line in FIG.
-2 is formed into a groove that opens on the connecting flat surface 2A, one end of this groove opens into the bearing hole 2B, and the other end opens into a part of the arc-shaped suction passage 6A, thereby connecting the bearing hole 2B and the suction passage 6A. will be contacted.

As a result, the drive shaft 3 rotates, and the outer teeth 4 of the inner rotor 4 rotate.
When the gap between the internal teeth 5A of the outer rotor 5 expands to form a suction space, the pressure ti in this suction space decreases, and this decrease in pressure causes the suction to open corresponding to the suction space. Oil is sucked into the suction space from the passage 6A, and at this time, oil also enters the oil passage 20 that opens to the suction passage 6A.

Therefore, the oil that has entered the oil passage 20 is driven from the open end of the oil passage 20 with respect to the bearing hole 2B! 111
3, oil lubrication of the drive shaft 3 and the bearing hole 2B is achieved.

Furthermore, if one end of the oil passage 20 is opened in the bearing hole 2B and the other end is opened in the suction passage 6A without opening it in the connecting flat surface 2A with pump force /< 2, (the dotted line in FIG. 2) During the suction process of the pump described above (as shown in FIG. 1), the pressure in the suction passage 6A and the oil passage 20 is reduced by the pressure drop in the suction space.

According to this, as oil flows into the suction passage 6A and the oil passage 20, the pressure drop in the oil passage 20 acts on the bearing hole 2B, and the reduced pressure acting on the bearing hole 2B causes the bearing hole 2B and the drive It acts on the connecting flat surface 2A of the pump cover 2 through a very small gap (for example 0.1 mm) between it and the shaft 3.

On the other hand, the outer teeth 4B of the inner rotor 4 and the outer rotor 5
The suction space and the discharge space formed by the inner teeth of the pump cover 2 have one side open to the connecting flat surface 2A of the pump cover 2, and a small amount of oil in the suction space or the discharge space is absorbed by the connecting flat surface of the pump cover 2. It is sucked into the bearing hole 2B through an extremely small gap between the connecting surface LA of the surface 2A and the connecting flat surface LA of the pump case l.

Therefore, the bearing hole 2B is synergistically supplied with oil from the oil passage 20 and oil through the extremely small gap between the connecting flat surfaces 2A and IA, so that the drive shaft Therefore, the lubrication of the pump cover 2 of No. 3 can be performed even better.

Note that a combination of a groove opening the oil passage into the connecting flat surface and a passage opening directly into the bearing hole may be used.

〔Effect of the invention〕

As described above, according to the oil pump device of the present invention, since the oil passage connected to the suction path is opened in the bearing hole of the pump cover, oil can be actively supplied to the bearing hole of the pump cover. This makes it possible to reduce the gap between the bearing hole of the pump cover and the drive shaft to less than half that of the conventional one, and the driving force is applied at an angle to the longitudinal axis of the drive shaft. The drive shaft can be reliably centered in the bearing hole of the pump cover and the pump case, which improves the durability of the bearing part (bearing hole, drive shaft). It was able to suppress core runout.

It is particularly suitable for using the end of the drive shaft as an output shaft.

In addition, by forming the oil passage as a groove on the connecting flat surface of the pump case, in addition to the above-mentioned effects, manufacturing is easier, and the pump case can be molded, especially integrally cast. It is. Furthermore, the effective cross-sectional area of the oil passage can be freely selected.

Furthermore, remove the oil passage from the connecting flat surface of the pump cover.
According to the opening in the bearing hole of the pump cover, the oil in the suction space and discharge space could be sucked into the bearing hole through a small gap in the connecting flat surface due to the reduced pressure from the oil passage. This allows oil to be supplied over relatively the entire circumference of the hole, further improving the effectiveness of oil lubrication of the bearing.

Note that the other end of the drive shaft does not necessarily need to be used as an output shaft.

[Brief explanation of drawings]

Figure 81 is a longitudinal cross-sectional view showing a conventional oil pump device.
The figure is a longitudinal sectional view showing an embodiment of the oil pump device of the present invention. 1. Pump case 2. Pump cover 3. Drive shaft 5. Outer rotor 20. Oil passage.

Claims (3)

[Claims] (1) An inner rotor that is fitted into a drive shaft that is rotatably supported by a pump case and a pump cover that covers the pump case, rotates together with the drive shaft, and has external teeth; an outer rotor having internal teeth that mesh with external teeth of the inner rotor; an inner rotor and an outer rotor are arranged in a rotor storage chamber formed by a pump case and a pump cover; A pump rotatably supporting a drive shaft in an oil pump device comprising: a suction space and a discharge space formed by teeth; a pump cover having a suction passage connected to the suction space and a discharge passage connected to the discharge space; An oil pump device in which an oil passage connected to a suction passage is opened in a bearing hole of a cover. (2) The oil pump device according to claim 1, wherein the oil passage is opened as a groove in a connecting flat surface of a pump cover that is joined to a connecting flat surface of the pump case. (3) The oil pump device according to claim 1, wherein one end of the oil passage is opened to a bearing hole of the pump cover excluding a connecting flat surface of the pump cover, and the other end is opened to a suction passage.