JP3533917B2 - Oil pump - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil pump formed by accommodating a pump element near a mating surface between a pump cover and a pump housing and interposing a sealing ring on the mating surface.

[0002]

2. Description of the Related Art As shown in FIG. 6, a technique is known in which a sealing ring 40 is used to secure a sealing property between a pump cover 20 and a pump housing 30 forming an oil pump case 10. However, the axial length W of the pump cover 20 and the pump housing 30
If the outer diameter R of the pump cover 20 is restricted, the pump cover 20 and
Also, a spigot portion (a fitting portion having an uneven shape) for coaxially positioning the pump housing 30 cannot be set.

For this reason, as shown in FIG. 6, instead of providing the spigot portion on the pump cover 20 and the pump housing 30, there is a pump cover 20 and the pump housing 30 in which a pin P having a small diameter is penetrated for positioning.

[0004]

However, when the pin P is used for positioning, a new problem arises that the number of parts and the number of assembling steps increase. Moreover, when the distance ΔL from the pump element (the inner gear 50 and the outer gear 60 integrated with the shaft 70 in FIG. 6) to the outer peripheral portion of the pump housing 30 is short, the sealing ring 40 and the pin P are combined together as in the conventional case. Difficult to lay out.

As is clear from the above description, the problem to be solved by the present invention is to position the pump cover and the pump housing coaxially without increasing the number of parts and the number of assembly steps, and therefore the positioning means on these mating surfaces. And the seal ring can be laid out together.

[0006]

In order to solve this problem, the oil pump according to claim 1 of the present invention comprises:
In an oil pump formed by accommodating a pump element near a mating surface of a pump cover and a pump housing and interposing a sealing ring on the mating surface, the pump cover has the protrusion on the mating surface of the pump housing.
There is a ring-shaped groove that fits the parts, and this ring shape
Groove fitted with a sealing ring of and is characterized by having a groove of a ring-shaped ing a sealing ring is fitted with projections of the pump cover.

The oil pump according to a second aspect of the present invention is the oil pump according to the first aspect, wherein the outer diameter dimension of the ring-shaped groove is smaller than the outer diameter dimension of the sealing ring by a predetermined dimension. It is characterized by that.

The oil pump according to claim 3 of the present invention is the oil pump according to claim 1, wherein the inner diameter of the ring-shaped groove is larger than the inner diameter of the sealing ring by a predetermined dimension. It is a feature.

[0009]

The oil pump according to the first aspect of the present invention is such that when the pump element is housed in the vicinity of the mating surface of the pump cover and the pump housing, the protrusion of the pump cover is used for the sealing. It is formed by fitting together with a ring into a ring-shaped groove in the pump housing.

Therefore, according to the present invention, the means for coaxially positioning the pump cover and the pump housing are formed by the protrusion on the pump cover and the ring-shaped groove on the pump housing, and the protrusion and the ring-shaped groove are formed. Since the sealing ring is interposed between the positioning means and the ring-shaped sealing ring, the positioning means and the ring-shaped sealing ring are laid out together on the mating surfaces of the pump cover and the pump housing without increasing the number of parts and the assembly man-hour for the positioning means. it can.

The oil pump according to a second aspect of the present invention is the oil pump according to the first aspect, wherein the outer diameter dimension of the ring-shaped groove is smaller than the outer diameter dimension of the sealing ring by a predetermined dimension. Therefore, when the seal ring is assembled, the seal ring can be prevented from falling off.

The oil pump according to claim 3 of the present invention is the oil pump according to claim 1, wherein the inner diameter of the ring-shaped groove is larger than the inner diameter of the sealing ring by a predetermined dimension. The same effect as that of the second aspect can be obtained.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an oil pump according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view of an essential part showing an outline of a first embodiment according to the present invention. This is an internal gear type oil pump housed in an automatic transmission and equipped with a torque converter (not shown) on the right side of the drawing, in which an oil pump case 1 is formed by a pump cover 2 and a pump housing 3, and a pump element is provided. Inner gear 5 and outer gear 6
Are those which are inscribed and meshed in the recess 2i provided in the pump cover 2.

The inner gear 5 is integrally attached to an input member (shaft) 7 which is connected to a pump impeller (not shown) from the torque converter.
When is rotated, the inner gear 5 rotates the outer gear 6 in the oil pump case 1 to change the capacity of the pump chamber defined between the outer teeth of the inner gear 5 and the inner teeth of the outer gear 6. As a result, the oil in the pump chamber is compressed and discharged as pump pressure. Reference numeral 8 is a stator shaft of the torque converter.

The oil pump according to the present invention will now be described in detail.

The pump cover 2 has a protrusion 2p on the mating surface with the pump housing 3, and the pump housing 3 is
A ring-shaped groove 3f is provided on the mating surface with the pump cover 2. Therefore, in the oil pump according to the present invention, when the inner gear 5 and the outer gear 6 are housed near the mating surface of the pump cover 2 and the pump housing 3, the protrusion 2p of the pump cover 2 is sealed with a ring (hereinafter referred to as a sealing ring). ,
It is formed by fitting together with the O-ring 4 into the ring-shaped groove 3f in the pump housing 3.

As for the procedure for assembling the oil pump case 1, as shown in FIG. 2, first, the O-ring 4 is attached to the ring-shaped groove 3f of the pump housing 3. Then, the inner gear 5 and the outer gear 6, which are pump elements, are housed in the recess 2i in the pump cover 2, and the pump housing 3 to which the O-ring 4 is attached is assembled. As a result, the oil pump case 1 is formed.

FIG. 3 is an enlarged view of a main part illustrating a state in which the O-ring 4 is attached.

In FIG. 3A, the outer diameter dimension Rfo of the ring-shaped groove 3f is made smaller than the outer diameter dimension Rso of the O-ring 4a by a predetermined dimension. This can prevent the O-ring 4a from falling off when assembled.

In FIG. 3B, the inner diameter Rfi of the ring-shaped groove 3f is made larger than the inner diameter Rsi of the O-ring 4b by a predetermined dimension. Also in this case, it is possible to prevent the O-ring 4b from falling off when assembled.

FIG. 4 is a sectional view showing the outline of the second embodiment according to the present invention. This forms the oil pump case 1 with the pump cover 2 and the pump housing 3,
An inner gear 5 and an outer gear 6, which are pump elements, are internally meshed with each other in a recess 3i provided in the pump housing 3.

Also in this oil pump case 1, when the inner gear 5 and the outer gear 6 are housed in the vicinity of the mating surface between the pump cover 2 and the pump housing 3, the protrusion 2p of the pump cover 2 is pumped together with the O-ring 4. It is formed by fitting into the ring-shaped groove 3f in the housing 3.

As shown in FIG. 5, the procedure for assembling the oil pump case 1 is as follows. 6 is stored, and then the pump cover 2 is assembled. This forms an oil pump.

In this embodiment, since the O-ring 4 is attached to the pump housing 3 together with the inner gear 5 and the outer gear 6, the O-ring 4 and the ring-shaped groove 3f are prevented from falling off as shown in FIG. Setting is not required.

As described above, according to the present invention, the means for coaxially positioning the pump cover 2 and the pump housing 3 is formed by the protrusion 2p of the pump cover 2 and the ring-shaped groove 3f of the pump housing 3, Since the O-ring 4 is interposed between the protrusion 2p and the ring-shaped groove 3f, the positioning means can be provided on the mating surfaces of the pump cover 2 and the pump housing 3 without increasing the number of parts and the number of assembly steps for the positioning means. The O-ring 4 can be laid out together.

The above description merely shows the preferred embodiments of the present invention, and those skilled in the art can make various modifications within the scope of the claims. For example, such an oil pump is used in an automatic transmission for a vehicle, and an O ring is a rubber ring,
A Teflon ring or the like can be used.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view for explaining a first embodiment of an oil pump of the present invention.

FIG. 2 is a partial cross-sectional view illustrating an assembling method in the same embodiment.

3 (a) and 3 (b) are partial cross-sectional views illustrating a method for attaching a sealing ring.

FIG. 4 is a partial cross-sectional view for explaining a second embodiment of the oil pump of the present invention.

FIG. 5 is a partial cross-sectional view illustrating an assembling method in the same embodiment.

FIG. 6 is a partial cross-sectional view showing a conventional oil pump.

[Explanation of symbols]

1 oil pump case 2 pump cover 2f Ring-shaped groove (pump cover side) 2i hollow (pump cover side) 2p protrusion (pump cover side) 3 pump housing 3f Ring-shaped groove (pump housing side) 3i recess (pump housing side) 3p protrusion (pump housing side) 4 Seal ring 5 Inner gear 6 Outer gear 7 Pump impeller side input member (shaft) 8 Stator shaft

Claims (3)

(57) [Claims] 1. An oil pump formed by accommodating a pump element in the vicinity of a mating surface between a pump cover and a pump housing and interposing a sealing ring on the mating surface, wherein the pump cover and the pump housing are The pump housing has a protrusion on the mating surface, and the pump housing has a ring-shaped groove for fitting the protrusion on the mating surface with the pump cover.
Attach the sealing ring to the ring-shaped groove, and fit the sealing ring together with the protrusion of the pump cover.
Oil pump according to claim Rukoto such Te. 2. The oil pump according to claim 1, wherein the outer diameter dimension of the ring-shaped groove is smaller than the outer diameter dimension of the sealing ring by a predetermined dimension. 3. The oil pump according to claim 1, wherein an inner diameter dimension of the ring-shaped groove is larger than an inner diameter dimension of the sealing ring by a predetermined dimension.