JPS6032328Y2 - engine oil pump - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a structural improvement of a crescent type (internal gear type) oil pump that is directly connected to the crankshaft of an engine.

Conventionally, as shown in FIG. 1, a first pump case 4 is formed using a cover 3 of a timing chain 2 driven by an engine crankshaft 1, and a second pump case 4 is fixed inside the first pump case 4. Between the pump cases 5, an external gear 6 is coaxially fixed to the crankshaft 1, and an internal gear 7, which has a larger diameter than the external gear 6, is made eccentric so as to partially mesh with the external gear 6. A crescent type oil pump in which a crescent 8 is interposed in a crescent-shaped space formed between an external gear 6 and an internal gear 7 is well known.

By the way, in this type of oil pump, the leaking oil with high pressure that accumulates in the space 10 between the oil seal 9 supported on the first pump case 4 and the internal gear 6 is removed by drilling a hole vertically downward in the first pump case 4. An oil draining structure is employed in which oil is returned into the oil pan 12 through an oil return passage formed by a hole 11 and prevents oil from leaking from the oil seal 9 to the outside of the engine.

However, in such an oil draining structure, the first pump case 4, which is provided with the oil return passage 11 outside the engine and away from the internal gear 7, needs to be thick enough to provide the oil return passage 11. Also,
The case 14 of the oil pan 12 must be fixed to the flange edge 15 on the outside of the opening of the oil return passage 11 projecting outward from the first pump case 4, which requires extra space. Furthermore, there is a structural problem in that the auxiliary drive pulley 17 equipped with the belt 16 fixed to the shaft end of the crankshaft 1 must be mounted on the outside so as not to interfere with the part where the case 14 is fixed to the flange edge 15. there were.

The present invention was developed in view of these structural problems, and by forming the oil return passage using a crescent, the engine oil pump itself can be made more compact, and the structure around the pump can be made more compact. The present invention aims to provide an engine oil pump that can be made more compact.

That is, in the present invention, the oil return passage is formed as a passage that sequentially passes through the first pump case, the crescent, and the second pump case and reaches the oil pan, so that leakage oil that accumulates between the oil seal and the external gear can be removed. This is a distant relative of the above objective by having a structure in which oil is returned to the oil pan.

Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments.

In FIGS. 2 and 3, 20 is a cylinder block 21
an engine crankshaft supported by a bearing 22;
23 is a first pump case formed by outwardly inflating the cover 27 of a timing chain 26 driven by a sprocket 25 coaxially fixed to the crankshaft 20 by a key 24; 28 is a bolt attached to the inner wall surface of the first pump case 23; the second pump case fixed by 29, 3
0 is supported between the first pump case 23 and the second pump case 28 so as to co-rotate with the collar 31 on the outer periphery of a collar 31 which is coaxially and co-rotatably attached to the crankshaft 20 by the key 24. external gear,
Reference numeral 32 denotes an internal gear which has a larger diameter than the external gear 30 and is rotatably supported on the inner circumference of the first pump case 23 eccentrically with respect to the crankshaft 20 so as to mesh with the upper side of the external gear 30. , 33 is a crescent formed integrally with the first pump case 23 so as to partially fill the crescent-shaped space formed between the external gear 30 and the internal gear 32;
The external gear 3 is attached to the outer inner circumference of the first pump case 23.
An oil seal 36 is supported with a certain space 35 separated from the side surface of 0, and a bolt 3 is attached to the shaft end of the crankshaft 20 via a washer 38 in order to drive auxiliary equipment with a belt 37.
This is a pulley fixed by 9.

And the above 1. The second pump cases 23 and 28, the external gear 30, the internal gear 32, and the crescent 33 constitute an oil pump driven by the crankshaft 20,
As shown in FIG. 3, oil is drawn from a suction port 40 that is provided in communication with the space between the external gear 30 and the internal gear 32 on the end side of the crescent 33 on the leading side with respect to the rotational direction of the crankshaft 20. The oil in the oil pan 42 is sucked in through the suction pipe 41, the sucked oil is interposed between the crescent 33, and the oil is added between the external gear 30 and the internal gear 32 on the trailing side of the crescent 33. It has a basic configuration in which oil is discharged into an oil discharge pipe 44 from a discharge port 43 provided in communication with the space between the two gears 30 and 32.

In the present invention, as clearly shown in FIG. A passage hole 45a of the first pump case 23 extends downward while being inclined inward (within the pump case 23), and a passage hole 45 of the crescent 33 passes through the crescent 33 in the width direction from the lower end of the passage hole 45a.
b, and a second pump case 28 that is continuous with the passage hole 45b of the crescent 33 and is provided through the second pump case 28 in its thickness direction.
The oil in the space 35 is passed through the first pump case 23, the crescent 33, and the second pump case 28 in this order, and then flows from the second pump case 28 side to the oil pan 42. I'm trying to get it back within.

If the oil return passage 45 is formed as described above, the flange edge 42a of the oil pan 42 will be 1. Bolts 47 are attached to the lower end surface of the pump case 23.
Since the oil pump can be directly fixed, the axial thickness of the oil pump itself can be reduced, and at the same time,
The mating surface with the oil pan 42 can be brought closer to the engine body side than in the conventional structure.

In addition, in the conventional structure, since the flange edge 15 of the first pump case 4 exists, the pulley 17 for driving the auxiliary equipment must be attached to the outside of the flange edge 15, but in the present invention, the flange edge 15 is unnecessary. Pulley 3
6 can be brought close to the engine body side so as to cover the first pump case 23 from the outside, the length of the engine as a whole can be shortened, and the space around the engine float can be secured.

As is clear from the above description, the present invention provides an oil return passage that returns leaked oil that accumulates in the space between the oil seal and the external gear to the oil pan by using the holes drilled in the crescent and the second pump case. An oil pump for an engine is provided.

According to the present invention, not only can the thickness of the oil pump itself be reduced, but also the structure around the oil pump can be made compact, and the length of the engine can be shortened. can.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of a conventional crescent type oil pump, FIG. 2 is a vertical sectional view of an oil pump according to the present invention, and FIG. 3 is a sectional view taken along the line II in FIG. 20... Crankshaft, 23...
1st pump case, 28...2nd pump case, 30...external gear, 32...internal gear, 33...crescent, 34... ...Oil seal, 35...Space, 45...
oil return passage.

Claims (1)

[Scope of utility model registration request] disposed between the first pump case and the second pump case,
A crescent is disposed between an external gear and an internal gear operated by the crankshaft, and a crescent is formed between the external gear and an oil seal disposed between the tip of the crankshaft and the first pump case. An engine oil pump characterized in that an oil return passage is formed by communicating the space formed in the crescent and the hole bored in the second pump case.