JPS5842629Y2 - gear pump or motor - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a gear pump or motor (hereinafter referred to as a gear pump, etc.) in which the sliding surfaces of the gear and the bush or side plate are prevented from seizing.

In conventional gear pumps and the like, the side surfaces of the fishes or side plates, that is, the sliding surfaces with the gears, are flat.

However, in this case, there was a drawback that the sliding surface was easily seized due to the following reason.

First, when the gear pump etc. rotates at high speed.

Tooth groove pressure tends to decrease.

As a result, the bushing or side plate is pressed against the side surface of the gear with more force than necessary.

However, considering lubrication theory, the sliding surface with this gear is a parallel flat plate and does not have the function of a normal thrust bearing.

As a result, an oil film is formed on the sliding surface, which is likely to seize.

In conventional gear pumps, the sliding surfaces are susceptible to burning, which has been an obstacle to achieving higher pressures and higher speeds.

Purpose of this invention This invention prevents the above-mentioned sliding surface from burning out, and
The purpose is to provide a gear pump, etc. which can also prevent oil leakage from a bearing part.

Embodiment In the illustrated embodiment of the gear pump of the present invention, a pair of bushes 3 and 4 are provided in a figure-eight body bore 2 formed in a body 1.
is inserted.

A high-pressure area and a low-pressure area are formed on the back surface of the fish 3.4 (neither of these areas are shown, however).

The high pressure area and the low pressure area are provided with a gear 5,
The pressure is introduced in accordance with the distribution of the tooth groove pressure of No. 6.

On the side surfaces of the bushings 3 and 4 as described above, that is, on the sliding surfaces with the gears 5 and 6, a large number of irregularities 7 and 8 are formed radially outward from the tooth root circle of the gears. ing.

The depth of the concave portions of the unevenness 7 and 8 is approximately several microns to 20 microns.

However, when the pump is rotated, the oil in the tooth grooves is
It flows into the recesses of the above-mentioned unevenness.

Therefore, an oil film is always maintained on the side of this bushing.
No oil slick runs out.

Moreover, the above-mentioned unevenness is larger than the dedendum circles of the gears 5 and 6.

Since it is formed outward, oil inside the unevenness does not flow into the bearing part.

First, there is no oil leakage to the bearings.

Structure of the present invention The advantage of this invention lies in the fact that a large number of concave and convex portions are formed radially on the side surface of the bushing or side plate, that is, the sliding surface with the gear, outward from the dedendum circle of the gear. Has characteristics.

Therefore, when the gear pump or the like is rotated, the oil in the tooth grooves flows into the unevenness.

Effects of the present invention According to this invention, the oil in the tooth grooves flows into the unevenness formed on the bushing or side plate, so that there is no oil film on the sliding surface.

Therefore, even when the pump or the like is operated at high speed, the sliding surface does not seize.

Also, since the above-mentioned unevenness is formed outward from the tooth root circle of the gear, oil flowing into the unevenness will not leak into the bearing portion.

If oil were to leak into the bearing, the bearing would be damaged by the contamination contained in the oil, but with this invention there is no such concern.

[Brief explanation of drawings]

The drawings show an embodiment of this invention, with FIG. 1 being a sectional view and FIG. 2 being a plan view of the bushing. 3.4...button 5,6...gear, 7,8...
・Irregularities.

Claims (1)

[Scope of utility model registration request] A gear pump or motor in which a high-pressure area is formed with metal on the back of the bushing or side plate provided on the side of the gear, high pressure is guided to this high-pressure area, and the bushing or side plate is strongly pressed against the side of the gear to prevent oil leakage from the side of the gear. A gear pump or motor, wherein a large number of concavities and convexities are formed radially on the side surface of the bush or side plate, that is, the sliding surface with the gear, outward from the dedendum circle of the gear.