JPS60159388A - Oil pump for engine - Google Patents

Abstract

PURPOSE:To obtain a compact oil pump for engine and reduce the amount of the oil leak by forming a pump chamber between a case body and a bearing boss for supporting the edge part of a cam shaft and driving a pump shaft by the edge of the cam shaft. CONSTITUTION:The lower edge of a cam shaft 22 axially supported into the case body 21 of an engine is supported by a bearing boss 24 separately formed from the case body. A concaved part 26 for accommodating a pump rotor 25 is formed onto the inner surface of the case body, and a pump chamber is formed by fixing the above-described bearing boss. A pump shaft 34 is supported by the case body and a bearing part formed onto the bearing boss 24, and the upper edge part extends into the bearing boss 24 and engaged witht the edge of the cam shaft so that a turning moment can be transmitted. Therefore, the oil pump can be perfectly installed into the case body of the engine.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to the structure of the oil pump,
In particular, the installation of an engine oil pump of the type that is provided within the engine case body and driven directly by the shaft end of a camshaft is structurally related.

[Prior art]

In engines with a camshaft located inside the engine case body, such as side pulp type 4-cycle engines, lubricating oil (oil) stored at the bottom of the case body is pumped to the main bearing of the crankshaft. As a means, an oil pump directly driven by the shaft end of the camshaft may be used.

The conventional structure of this type of oil pump (lubricating oil pump) is, for example, assembly No. 111857-52323 (Utility Application No. 54-5
4119) and Utility Model Application No. 57-167210 (Utility Model Application No. 56-54216).

First, the structure of these conventional oil pumps for axle-type engines will be explained with reference to FIG. The shaft is supported vertically. A bearing groove 4 for bearing the lower end of the camshaft 3 and a recess 5 opening outward at a concentric position below the bearing groove are integrally formed at the bottom of the case body l. This recess 5 forms a pump chamber, and after inserting the pump rotor, the pump rotor is held by fastening a cover 8 to the outer surface of the case main body with a del door. The pump shaft 9 is supported in a through hole formed in a partition wall between the bearing disk 4 and the recess 5, and its tip engages with the shaft end of the camshaft 3. Further, an oil inlet IO of the pump is formed at the back of the recess 5, that is, at the upper end.

The discharge port 11 of the pump communicates from the pump chamber 5 into the bearing goose 4, and the oil is fed upward through the oil guide hole 12 formed in the camshaft 3, and then the oil is sent upward to the crankshaft main bearing 1.
3 etc.

Around the bearing post 4, there is a wall-like protrusion 14 (which may be a wall having an oil passage hole) defining a filtration chamber 15.
is formed integrally with the case body 1, and a filter element 16 installed in the filtration chamber 15 is held by a filter holder 17 attached to the upper end of the wall-like projection 14. In addition, the code|symbol 18 shows an oil level.

The conventional oil pump structure described above with reference to FIG. 1 has the following problems.

(1) Since the pump rotor is inserted into the recess 5 and then the cover 8 is fastened to hold the pump rotor, oil leakage may occur at the cover mounting surface (gasket surface).

(I+) Since the heads of the cover 8 and the mounting port 7 protrude from the surface of the case body 1, the external dimensions of the engine become larger. Note that if the cover mounting surface is recessed so that this portion does not protrude, machining the gasket surface will become difficult.

0ii) In the case of an axle-type engine as shown, since the pump inlet 10 is formed in the upper part of the recess (pump chamber) 5, the range between the highest and lowest oil levels is reduced; The amount of oil that can be used effectively decreases.

[Purpose of the invention]

The purpose of the present invention is to solve these conventional problems and provide a camshaft-driven oil pump that eliminates the possibility of oil leakage (by removing the cover) and eliminates the protrusion on the surface of the case body. It is to provide.

The feature of the present invention is that the above object is achieved by forming the bearing disk as a separate part from the case body, attaching the bearing disk to the inside of the case body, and forming a pump chamber therebetween. .

[Structure of the idea]

That is, according to the present invention, in an engine oil pump that is provided within the engine case body and is directly driven by the shaft end of the camshaft, the bearing disk that supports the end of the camshaft is separate from the case body. A pump shaft is formed of a body part, and a pump chamber is formed between the bearing disk and the case body by attaching the bearing disk to the inside of the case body, and the pump shaft extends from the pump chamber into the bearing disk. An oil pump for an engine is provided, characterized in that the oil pump is driven by the shaft end of the camshaft.

〔Example〕

The present invention will be described in detail below with reference to FIGS. 2 and 3.

In FIGS. 2 and 3, the engine case body 2
A camshaft 22 is rotatably supported within 1. The illustrated example shows the case of an axle-type engine.

The lower end of the camshaft 22 is supported by a bearing 24 that is separate from the case body. This bearing disk 24 is fixed to the inside of the case body 21 by a port 23. In the illustrated example, the bearing goss 24 is fixed to a part of the spigot in an accurately centered state.

A recess 26 for accommodating the pump rotor 25 is formed on the inner surface of the case body 21, and a sealed f7f chamber is defined by fixing the bearing goss 24.

The case body 21 also serves as an oil reservoir, and oil is stored at the bottom up to a level 27.

Further, the case body 21 is formed with a pump suction port 28 and a pump discharge port 29 as shown in FIG.
The oil from 9 is supplied to the main bearing, big end, etc. of the crank through the oil guide hole 30. An IJ/IJ-7 valve 31 is provided in the middle of the oil guide hole 30 so as to be able to adjust the oil supply pressure.

A screen (or filter) 32 is disposed at a position surrounding the oil suction port 28, and the screen is held in a predetermined position by being pressed by a projecting portion 33 formed integrally with the bearing boss 24.

The shaft of the pump rotor 25, that is, the pump shaft 34, is supported by a bearing portion formed in the case body 21 and the bearing boss 24, and the upper end portion extends into the bearing boss 24 so that rotational force can be transmitted to the end of the camshaft shaft. engaged.

Note that as the oil pump, in addition to a rotary pump having a pump rotor 25 such as a trochoid pump, various types such as a gear pump, a vane pump, or a plunger pump can be used.

The camshaft 221C is provided with a driven gear 35 for receiving rotation of the crankshaft, and a cam portion 40.41 that abuts each tappet 38.39 of the intake valve 36 and the exhaust valve 37.

According to the embodiment described above with reference to FIGS. 2 and 3, the oil pump is all constructed inside the case body, so the cover (cover 8 in FIG. 1) in the conventional structure can be removed. , eliminating the possibility of oil leakage. At the same time, since parts such as the cover and cover mounting bolts that protrude from the surface of the case body are eliminated, the external dimensions of the engine can be reduced.

In addition, since all machining of the case body 21 can be done from the inside, machining is easy and centering of the camshaft bearing portion and the pump is also easy.

Furthermore, since the bearing boss 24 also serves as a screen holder, it is possible to reduce the number of parts.

Furthermore, in the case of a shaft type engine as shown in the figure,
Since the position of the pump suction port 28 can be lowered compared to the conventional structure, the difference between the upper and lower limits of the oil level 27 can be increased, and the effect of increasing the amount of oil that can be effectively used can also be obtained.

In the above embodiments, the present invention is applied to a support shaft type engine, but the present invention can be similarly applied to a horizontal shaft type engine or a tilted shaft type engine.

〔Effect of the invention〕

As is clear from the above description, the present invention provides an engine oil pump that can eliminate the possibility of oil leakage and can also eliminate protrusions on the surface of the case body.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view illustrating a conventional oil pump, FIG. 2 is a longitudinal sectional view illustrating an embodiment of an engine oil pump according to the present invention, and FIG. 3 is a longitudinal sectional view illustrating an oil pump for an engine according to the present invention. FIG. 3 is an enlarged longitudinal cross-sectional view seen from another angle. 21...Case body, 22...Camshaft, 24...
Bearing gear (cam a), 25... pump rotor, 26...
... recess (pump chamber), 27 ... oil level, 34
...Pump shaft.

Claims (1)

[Claims] (1) In an engine oil pump that is installed inside the engine case body and driven directly by the end of the camshaft, the bearing that supports the end of the camshaft is a separate part from the case body. By forming the bearing plate and attaching the bearing plate to the inside of the case body, a pump chamber is formed between the bearing plate and the case body, and the bearing plate is removed from the pump chamber. An oil pump for an engine, characterized in that a pump shaft extending into the engine is driven by a shaft end of the camshaft.