JPH06147133A - Gear pump - Google Patents

Abstract

PURPOSE:To prevent a body and a mounting flange, and the body and a cover from being skidded mutually. CONSTITUTION:A body B is composed of a hard steel material, and a mounting flange M and a cover are made of soft aluminum, and at the same time a number of processing teeth 13 is set lengthwise and in parallel with each other on both sides of the body B and recesses and projections are formed. By coupling these by means of tie-bolts 7-10, the mounting flange M and the cover are made to be bitten into the recesses and projections of the body B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear pump which prevents the body and a closing member from being displaced.

[0002]

2. Description of the Related Art In the conventional gear pump shown in FIGS. 2 and 3, both sides of a body B incorporating a drive gear 1 and a driven gear 2 are covered with a mounting flange M and a cover C. Then, the shafts 3 to 6 of the gears 1 and 2
Are rotatably supported by the mounting flange M and the cover C. The body B, the mounting flange M, and the cover C thus configured are securely fastened with four tie bolts 7 to 10. Now, when the drive gear 1 and the driven gear 2 are rotated, the fluid sucked from the low pressure port 11 is carried by the tooth spaces of both gears 1 and 2 and discharged from the high pressure port 12.

[0003]

In the conventional gear pump as described above, there is a problem that the body B and the mounting flange M or the body B and the cover C slip and cause a relative displacement. The causes are as follows. That is, when this pump is driven, the pressure on the high-pressure port 12 side becomes very high, but the high pressure generally acts in the range indicated by the arrow H. Thus, when the pressure difference between both sides of the body B becomes large,
Since it also acts on the mounting flange M and the cover C, they slip on the low pressure side, and the relative displacement occurs as described above.

The means for preventing this deviation are the tie bolts 7-10, but the relative deviation cannot be completely prevented only by the frictional force of the tie bolts. When the body B and the mounting flange M or the cover C are relatively displaced in this way, oil leaks from between them or the meshing of the gears 1 and 2 is displaced, resulting in poor pump efficiency. The problem occurs. An object of the present invention is to provide a gear pump which has a simple structure and is low in cost, and which can prevent the body from being displaced from a closing member such as a cover.

[0005]

The present invention comprises a body incorporating a pair of gears, a closing member such as a cover for closing one or both sides of the body, and a tie bolt for fastening the body and the closing member. It is based on a gear pump. While assuming the above gear pump,
This invention comprises one of the above-mentioned body and the closing member, which is made of a harder material than the other,
It is characterized in that a large number of concavities and convexities are formed in parallel on the mating surface of a body or a closing member made of a hard material, the concavities and convexities running in a direction substantially perpendicular to the sliding directions of the both.

[0006]

Since the present invention is configured as described above, when the body and the closing member are fastened with tie bolts, the mating surface of the closing member bites into the unevenness formed on the side surface of the body.

According to the gear pump of the present invention, the unevenness of the body traveling in the direction perpendicular to the slip direction bites into the closing member, so that the deviation between the body and the closing member can be surely prevented, and the deviation can occur. It is also possible to prevent deterioration of pump efficiency. Further, since only the concave and convex portions are formed on the side surface of the body and no special parts are required, the structure is simple and the cost can be kept low.

[0007]

In the embodiment shown in FIG. 1, the body B is made of an iron-based material, and each of the mounting flange M and the cover C is made of aluminum, which is softer than the iron-based material. The both sides of the body B thus formed are provided with machined grooves 13 formed of vertical narrow grooves to form irregularities on the entire side surface of the body B. The vertical direction in which the irregularities are formed is a direction substantially perpendicular to the sliding directions of the body B and the mounting flange M, and the body B and the cover C. In this way, on both sides of body B,
The configuration is the same as that of the conventional gear pump shown in FIGS. 2 and 3 except that the processing mesh 13 is provided, and thus detailed description thereof will be omitted.

The aluminum mounting flange M and the cover C are fitted to both sides of the body B made of the iron-based material in which the machined stitches 13 are formed as described above, and they are firmly fastened with tie bolts 7 to 10. . By tightening with the tie bolts in this manner, the mating surfaces of the soft mounting flange M and the cover C bite into the irregularities of the hard body B. Therefore,
Even if the pressure of the high-pressure port 12 becomes high, the mounting flange M and the cover C will not be displaced.

In the above-mentioned embodiment, the machined stitches 13 are formed in a direction perpendicular to the sliding direction of the mounting flange M or the like. However, for example, mesh-shaped machined stitches 13 are formed to form irregularities. Good. In any case, any shape may be used as long as it has a concavo-convex shape that causes resistance in the sliding direction of the mounting flange M and the cover C. However, it is the easiest and cheapest method to form the unevenness by providing a large number of machined lines 13 in the vertical direction as in the above embodiment. Further, in the above embodiment, the unevenness is formed on both sides of the body B, but the unevenness may be formed on the mating surface of the mounting flange M or the cover C. However, in this case, the body B side must be made of aluminum, and the mounting flange M and the cover C side must be made of an iron-based material.

[Brief description of drawings]

FIG. 1 is a side view of a body with a cover removed.

FIG. 2 is a vertical sectional view of a conventional gear pump.

FIG. 3 is a sectional view taken along line III-III in FIG.

[Code]

 B body 1 drive gear 2 driven gear M mounting flange C cover 7 tie bolt 8 〃 9 〃 10 〃 13

Claims (3)

[Claims] 1. A gear pump comprising a body incorporating a pair of gears, a closing member such as a cover for closing one side or both sides of the body, and a tie bolt for fastening the body and the closing member. Either one of the members is made of a harder material than the other one, and a large number of members running on the mating surface of the body or the closing member made of a hard material in a direction in which the sliding direction of both of them becomes resistance A gear pump characterized by having irregularities. 2. The gear pump according to claim 1, wherein a large number of concavities and convexities running in a direction substantially perpendicular to each other are formed in parallel on the mating surface of the body or the closing member. 3. The gear pump according to claim 1, wherein the mating surface of the body or the closing member is provided with a mesh-like processed mesh to form irregularities.