JPS6050292A - Gear pump - Google Patents

Abstract

PURPOSE:To facilitate assembling of a gear pump employing a gasket, by applying the gasket such that the folding portion of gasket is separted from the stopper wall under initial supply stage of high pressure fluid and contact tightly onto the innercircumference of casing. CONSTITUTION:A gasket 12 is made by molding rubber into linear body having rectangular cross-section then the folding portion 15 at the end is contacted resiliently against the innercircumference 3a of casing 3. First stopper wall of land shape 16 located at the inside of folding section of gasket 15 and second stopper wall 17 co-operating with said wall 16 to hold the leading edge 15a of the folding section 15 thus to temporarily hold the folding section 15 at the position slightly inside of the innercircumference 1a of casing 1 are provided at the end 11a of the gasket groove 11. Consequently, temporary holding can be facilitated even when employing a gasket 12, resulting in facilitating assembly of end covers 4, 5 to the casing 3.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a hydraulic pump that can be used in the field of hydraulic equipment and the like.

(b) Prior Art In general hydraulic pumps, a minute gap is provided between the steel arrow of the gear and the inner peripheral surface of the casing, and between the tooth side surface and the side plate to ensure smooth operation of the gear. There is. Therefore, as the discharge pressure increases, there is a disadvantage that leakage from the gap increases, and in particular, leakage from the tooth side portions becomes a problem. Therefore, in modern hydraulic pumps, discharge pressure is introduced to the back side of the side plate to press the side plate against the end face of the gear. That is, in this case, a gasket groove is provided on the inner surface of the end cover facing the back side of the side plate, located at the boundary between the low pressure area and the high pressure area, and the caskerat attached to this gasket groove and the inner periphery of the casing. The high-pressure fluid on the discharge side is introduced into the high-pressure region surrounded by the surfaces. However, with such a configuration, there is a portion where the end of the 1111 force socket contacts the inner circumferential surface of the casing in a part of the regulation range of the high pressure region, and the contact point is The direction of sealability has become an important issue. To precisely place the gasket on the inner peripheral surface of the casing,
It is necessary to use a so-called molded gasket, but this type is expensive. It is also being considered to use an inexpensive linear gasket I instead of the molded gasket. That is, in this gasket, the end portion of the gasket is bent back into a hook shape using elastic deformation, and the newly curved portion is brought into elastic contact with the inner circumferential surface of the casing to effect sealing. However, with just this, the bent part of the gasket protrudes outward due to the elastic restoring force when the unit is assembled, so the soldered part of the end cover that holds the gas cap and 2 parts at 11 is attached to the inner periphery of the casing. The problem arises that it is difficult to fit.

(C) Purpose The present invention was made by paying attention to the above circumstances.
The range of the high pressure area formed on the back side of the side plate can be reliably regulated using an inexpensive linear gasket, and there is no inconvenience such as difficulty in assembly due to the use of a linear gasket. The purpose is to provide gear pumps.

(D) Structure In order to achieve the above object, the present invention regulates the range of the high pressure region formed on the back side of the side plate by using a linear gasket whose end is folded back and tightly attached to the inner circumferential surface of the casing. In the gear pump, an island-shaped first locking wall located inside the bent portion of the gasket is provided at the end of the gasket groove, and this first locking wall cooperates with the wall. and a second locking wall that clamps the tip of the bent portion and temporarily holds it on the samurai 2+ inside the inner circumferential surface of the casing. The present invention is characterized in that the curved portion is configured to come off from the space between the re-inspection 11 and the wall and come into close contact with the inner circumferential surface of the casing.

(e) Examples Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

As shown in FIG. 1, the gear pump according to the present invention includes a pump casing 3 housing a pair of gears l and 2 for oil feeding.
and an end cover 4.5 fitted to the open end of the pump casing 3 by fitting the dowel portions 4a and 5a into the inner periphery of the pump casing 3. The support shaft 6.7 of 1.2 is supported by a sliding bearing 8 provided on the end covers 4, 5. In addition, these inner surfaces 4b and 5b of each end cover 4 and 5 and the gears l and 2
A side plate 9 is interposed and sunk between the tooth side surfaces 1a and 2a, respectively. And the inner surface 4b of the end cuff 9-4, 5
, 5b, a gasket groove 11 is provided at the boundary between the high pressure area A and the low pressure area B, and a linear gasket 12 that closely contacts the side plate 9 is installed in the gasket groove 11.

The high pressure area A is located at the discharge boat 13 as indicated by diagonal lines in FIG.
The side plate 9 is connected to the gear 1.2 by the pressure of the high pressure fluid F introduced into this high pressure area A.
It is pressed against the south sides 1a and 2a of the On the other hand, the low pressure region B is the region on the side communicating with the suction bow 14 as shown in FIG.

The gasket 12 is formed by molding a material such as rubber into a linear body with a rectangular cross section, and the end portion is bent back into a hook shape using elastic deformation, and the bent portion 15 is attached to the casing. It is made to come into elastic contact with the inner circumferential surface 3a of No.3. As shown in FIGS. 3 and 4, the end portion 11a of the gasket groove 11 is provided with an island-shaped first locking wall 16 located inside the bent portion 15 of the gasket. The member 1 cooperates with the wall 16 to hold the tip 15a of the bent portion 15, and the bent portion 15
A second locking wall 17 is provided to temporarily hold the casing 1 at a position slightly inside the inner circumferential surface 1a of the casing 1.

With such a configuration, first, when assembling, the linear gasket 12 is attached to the gasket groove 11 provided on the inner surface of the end cover, and the bent part 15 (7) tip 1 is attached.
5atl-first locking wall 11-is held between wall 16 and second locking wall 17 (see FIG. 5). In this way, there is no problem that the bent portion 15 of the gasket 12 protrudes outward beyond the outer circumferential surface of the solder joint portion 4a due to elastic return force, and the solder joint W 4 a can be smoothly inserted into the casing 1. It can be fitted onto the inner periphery of the open end. Hence the linear gasket!・The use of 12 does not cause the inconvenience that it becomes difficult to assemble the end cover 4.5 to the casing 3. Moreover, in this way, silk)′/
After testing, when you test run this I&I IB pump,
The high-pressure fluid F from the discharge port 13 is also introduced into the high-pressure area A formed on the back side of the side plate 9, but the force of the high-pressure fluid F at the time of initial introduction causes the bent portion 15 of the gasket 12 to comes off from between the retest walls 16 and 17, and comes into close contact with the inner circumferential surface 3a of the casing 3 due to its own elastic return force and the fluid pressure in the high pressure area A. As a result, the range of the high pressure region A is reliably regulated, and operation with high volumetric efficiency becomes possible.

Note that the gasket is not limited to one having a square cross section, but may be one having a circular cross section, and the material is not limited to rubber, but may also be made of synthetic resin or other gasket materials. Moreover, the number of gaskets accommodated in the gasket groove is not limited to wood, and may be a plurality of gaskets.

(F) Effect Since the present invention has the configuration as described in H below, it is possible to reliably regulate the range of the high pressure region formed on the back side of the side plate using an inexpensive linear gasket. It is possible to provide a gear pump that does not cause problems such as difficulty in assembling due to the use of a shaped gasket.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a sectional view of 1]), FIG. 2 is a sectional view of H-H leech in FIG.
FIG. 4 is a partial stop view showing the gasket groove when the end force is fitted into the casing, FIG. 5 is a perspective view showing the ν part, FIG. 1.2... South center 1a, 2a... South side 31, casing 3a... Inner circumferential surface 4.5, e@end cover 4a, 5a@... Marking part 4b, 5b... Inner surface 9...Side plate 11...Casquera I, groove 12--, Gaskent 15...Bend portion 16, fist, first member I1. ．． Kabe 17: Second person in charge, Ichikabe agent, patent attorney Hiroshi Akazawa 9-60!

Claims (1)

[Claims] A pump casing containing vIIIt for oil feeding,
an end cover that is attached to the open end of the pump casing by fitting a solder fitting part to the inner periphery of the pump casing; and a seal interposed between the inner periphery of the end cover and the end of the gear. A side plate of the casing, a gasket groove provided at the boundary between the high pressure area and the low pressure area on the inner surface of the end cover, and a bent part accommodated in the gasket groove and formed by folding the end into a piece shape. A part of the high pressure fluid is introduced into a high pressure area surrounded by the gas socket and the inner circumferential surface of the casing to cause the side plate to close to the gear. The gear pump is configured to be pressed against the end face, and includes a first island-shaped locking wall located inside the bent portion of the gasket at the end of the gasket groove, and the first locking wall 1F. A second wall is provided that cooperates with the wall to clamp the tip of the bent portion and temporarily hold it at a position inside the inner circumferential surface of the casing, and the high-pressure fluid is initially directed to the high-pressure region. A gear pump characterized in that the new curved portion is configured to be able to come off from between the two walls and come into close contact with the inner circumferential surface of the casing when introduced.