JPH0151887B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an oil pump for engine lubricating oil, and more particularly, the present invention relates to an oil pump for engine lubricating oil, and more specifically, a pump that is attached to a side surface (mainly an end surface) of an engine block, and a part of the side surface of the engine block is connected to the pump. This invention relates to an oil pump for engine lubricating oil that forms one side of a housing.

(Prior Art and Problems to be Solved) Recently, various attempts have been made to reduce noise and improve reliability by driving an oil pump with a belt. In this case, it is not preferable to expose the belt for noise and safety reasons. However, housing the belt within the cover has the problem of increasing the axial dimension of the oil pump. It is therefore an object of the present invention to eliminate the above-mentioned disadvantages.

(Means for Solving the Problems by the Invention) That is, the present invention provides an oil pump for engine lubricating oil of the type described at the beginning, in which part or all of the housing for accommodating the rotor of the oil pump is a recess provided in the side surface of the engine block. and is formed between the inner circumferential surface of the engine block recess and the outer circumferential surface of the pump housing that fits into the recess, one end of which is connected to the suction port of the pump, and the other end of which is connected to the discharge port of the pump. The pump is characterized by sealing a small gap leading to the side with an elastically biased sealing member so as to partition the suction port side and the discharge port side of the pump.

(Function) A part or all (about half in the embodiment) of the rotor and housing of the oil pump are accommodated in a recess provided in the side surface of the engine block. Therefore, the protrusion of the oil pump from the side surface of the engine block is reduced, and the engine can be shortened in the axial direction of the oil pump. As a result, it becomes possible to attach the belt cover without increasing the size.

(Example) An example shown in the accompanying drawings will be described below to clarify the present invention.

In FIG. 1, an oil pump 1 according to the present invention
0 is one side (front end surface) of the engine block 30
The engine block 30 is fitted into a recess 31 provided in the engine block 30, and is driven via a pulley 12 fixed to a rotating shaft 11 that projects outward (forward) from the engine block 30. Illustrated oil pump 1
0 is a rotary pump (Feuerheld rotary pump) generally referred to as a trochoid pump, which pivotally supports a rotating shaft 11 and has an outer housing 13 that forms a space between it and the side surface of an engine block 30 to accommodate a rotor; an annular outer rotor 14 rotatably fitted within the housing 13; an inner rotor 15 having a rotation axis _O2 eccentric from the rotation axis _O1 of the outer rotor 14 and having a four-lobed trochoid curve; It consists of a rotating shaft 11 which is locked with a key 16 to an inner rotor 15 and is pivotally supported by an outer housing 13.

The outer housing 13 in the embodiment has a protruding ring portion 13a, and the inner circumferential surface of the ring portion 13a is in sliding contact with the outer circumference of the outer rotor 14. The housing 13 is constructed integrally with other parts, and is fixed to the side surface of the engine block 30 with bolts 17 as shown in FIG.
A seal 19 fitted into the pump shaft prevents oil from leaking radially outward from between the outer housing 13 and the engine block 30 to the pump shaft.

The ring portion 13a of this outer housing 13 is
It is fitted into the circular inner circumferential surface of a recess 31 provided on the side surface of the engine block 30 shown in FIG. The end faces of the outer housing 13, the outer rotor 14, the inner rotor 15, and the rotating shaft 11 on the block side constitute one plane, and are closely connected to the flat bottom 32 of the recess (indicated by the middle point in FIG. 3). Contact (slidable).

The recess 31 of the engine block 30 includes the above-mentioned flat bottom 32, a suction chamber recess 33 and a discharge chamber recess 34 cut deeper than the flat bottom 32.
(corresponding parts in FIG. 2 are surrounded by two-dot chain lines), a suction port recess 35, and a discharge port recess 36. The suction chamber recess 33 and the discharge chamber recess 34 form a suction chamber 37 between the rotors 14 and 15, respectively.
and a discharge chamber 38, which are separated from each other by a flat bottom 32a that traverses the radial direction of the recess 31. The suction port recess 35 and the discharge port recess 36 connect the suction chamber 37 and the discharge chamber 38 to the suction port 20 provided in the outer housing 13.
and communicates with the discharge port 21.

A notch 3 with a rectangular cross section is provided on the circumferential surface of the radial cross section 32a of the bottom 32 of the engine block recess 31.
9, 40 are provided, and these notches 39, 40
An elastic seal member 41 and a spring 42 that presses the elastic seal member 41 toward the center of the recess (pump) are arranged inside. Therefore, a ring-shaped space 43 is formed between the inner circumferential surface of the recess 31 and the outer circumferential surface of the ring portion 13a of the outer housing 13 due to machining accuracy.
This seal member 41 seals the pump so as to partition the discharge side and the suction side.

When the inner rotor 15 rotates in the direction of arrow A by a belt (not shown), the outer rotor 14 in contact with the inner rotor 15 also rotates in the direction A', and the gap between both rotors increases and decreases repeatedly. Since the oil inside is sent in the direction shown by arrow B, the suction port 2
0 and the discharge port 21 to perform the pumping action. In this case, when the pressure inside the discharge port 21 reaches a certain value or more, the relief valve 50, which is known per se and connected to the discharge port 21, opens and the pressure does not increase any further.

Flat bottom part 3 of the recess provided in the engine block
2 and the ring portion 1 of the outer housing opposite thereto.
There is a slight gap 44 between the end face 3a and the end face due to machining accuracy.

The seal member 41 is arranged so that the discharged oil is
This prevents the fluid from flowing back to the suction side through the gap 43. That is, the oil in the discharge chamber 38 leaks along the bottom part 32 from the gap 44, and leaks from the gap 43b on the discharge side.
to go into. This gap 43b is the discharge port recess 36
, the oil also enters from this intersection 43c. This intruding oil is in the form of a ring.
Each sealing member 41 divides and seals the gap 43 into a discharge side and a suction side.
Intrusion into d is prevented. As a result, the discharged oil is prevented from flowing back toward the suction side from the intersection 43e with the suction port recess 35 through these gaps 43a and 43d.

In the above embodiment, a trochoid type pump was used as the pump, but the present invention is not limited to this type of pump, and any rotary pump in which a suction chamber 37 and a discharge chamber 38 are formed on the left and right sides can be used. can.
Note that a known gear pump can also be used as this rotary pump. Further, the seal members in the notches 39 and 40 may not be pressed by springs, but may be arranged as seals 41a and 41b, respectively, as shown in FIGS. 4 and 5.

(Effects of the Invention) The structure and operation of the present invention are as explained above, and by fitting the housing into the side surface of the engine block, the pump and engine are made compact in the axial direction, and the suction chamber and discharge chamber are separated. The space between 〓, which is a passage for short-circuiting (space 43d in Figure 3), and the space between 〓, which is a passage that communicates both chambers (space 4 in the same figure).
3b and 43a) are sealed to separate the suction port side and the discharge port side, respectively, thereby preventing the discharged oil from flowing back to the suction side through these spaces, thereby increasing pump efficiency. In addition, in order to increase pump efficiency, we have designed a space between the bottom of the recess and the end of the ring (the first
It may be possible to make the gap 44 in the figure as small as possible, and the gap 43 in FIG.

The present invention makes it possible to prevent oil leakage in the radially outward direction with respect to the pump shaft by a seal member (seal 19) provided between the side surface of the engine block and the outer housing tightly fixed thereto. A seal member 41 blocks oil flow in the circumferential direction around the center. As a result, the present invention does not require high processing precision, is therefore low cost, and can shorten the engine length and improve pump efficiency with a simple seal structure.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an oil pump for engine lubricating oil according to the present invention, and FIG. 2 is a -
3 is a sectional view taken along the - line in FIG. 1, FIG. 4 is a diagram with a design change in the arrangement of the sealing member, and FIG. 5 is a sectional view taken along the - line in FIG. It is a diagram showing a design change of the arrangement of. 13...Outer housing, 13a...Ring portion, 14...Outer rotor, 15...Inner rotor,
30...engine block, 31...recess, 32
...bottom, 37...suction chamber, 38...discharge chamber, 3
9, 40...notch, 41, 41a, 41b...
Seal member.

Claims (1)

[Claims] 1. In an oil pump for engine lubricating oil that is attached to a side surface of an engine block and a part of the side surface of the engine block forms one side of the pump housing, part or all of the housing that accommodates the rotor of the oil pump is attached to the side surface of the engine block. It is arranged in a recess formed on the side surface, and is formed between the inner circumferential surface of the engine block recess and the outer circumferential surface of the pump housing that fits into the recess, with one end leading to the suction port side of the pump and the other end leading to the inlet side of the pump. An oil pump for engine lubricating oil, characterized in that a minute gap leading to the discharge port side of the pump is sealed by an elastically biased sealing member so as to separate the suction port side and the discharge port side of the pump. .