JPH08200237A - Bearing structure for internal gear pump - Google Patents

Abstract

PURPOSE: To realize high efficient pump operation and to make drivable by stable low frictional force regardless of fluid kind, temperature and pressure, by setting up a rolling bearing in the periphery of a driven internal gear of the internal gear pump. CONSTITUTION: An internal gear 13, driven by an external gear 12 fixed to a drive shaft 11, is rotatably held by a casing 14 by providing a fixed eccentric amount by the driven shaft 11. By rotating the drive shaft 11 in the clockwise direction, a fluid sucked from a suction port 16, after compressed by a space between the external/internal gears 12, 13, is delivered from a delivery port 17. Here is held the internal gear 13 rotatably to the casing 14 by a rolling bearing provided with rolls 15 arranged by a holder 16 with an equal pitch. In this way, a gear pump can be driven by stable low frictional force regardless of kind, temperature and pressure of fluid, to obtain the gear pump is small size having high performance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid pump, and more particularly to a bearing structure for an internal gear pump.

[0002]

2. Description of the Related Art Conventionally, an internal gear pump is composed of an external gear fixed to a drive shaft and a driven internal gear rotatably installed in a casing. However, the rotation support of the casing and the driven internal gear was a sliding bearing system by fluid lubrication.

[0003]

However, this has the following drawbacks. In conventional sliding bearings with fluid lubrication, problems such as seizure of the bearing due to the inclusion of dust, air bubbles, and air, decreased efficiency due to increased frictional resistance at low temperatures and high speeds, and galling at high loads occurred. The present invention has been made to eliminate the above drawbacks.

[0004]

The problems of the present invention have been described above. Next, means for solving the problems will be described. That is,
In an internal gear pump, a driving external gear, a driven internal gear driven by the driving external gear, and a rolling bearing on the outer periphery thereof are installed and held by a casing. The present invention is a bearing structure of an internal gear pump having the above structure.

[0005]

The problems and configurations to be solved by the present invention are as described above, and the embodiments of the present invention shown in the accompanying drawings will be described below. FIG. 1 is a sectional view of a rolling bearing type internal gear pump, and FIG. 2 is a sectional view of a conventional sliding bearing type internal gear pump.

First, a conventional slide bearing type internal gear pump will be described with reference to FIG. The internal gear 23 driven by the external gear 22 fixed to the drive shaft 21 is rotatably held by the casing 24 with a certain eccentric amount from the drive shaft 21. By rotating the drive shaft 21 in the direction of arrow 25, the fluid sucked from the suction port 26 is carried by the space between the external gear 21 and the internal gear 22 and discharged from the discharge port 27. At this time, since the fluid has a high pressure, the internal gear 23 is strongly pressed against the casing 24. This force is supported by the sliding bearing system due to the lubricity of the fluid existing in the clearance between the internal gear 23 and the casing 24. It will be a matter. Therefore, due to the presence of the type of fluid, temperature, pressure, dust, etc., problems such as reduction in efficiency due to friction, heat generation, and seizure are likely to occur.

Next, an embodiment of the present invention will be described with reference to FIG. The external gear 12 fixed to the drive shaft 11 drives the internal gear 13. At this time, the internal gear 13 is the roller 1
It is held in the casing 14 via the 5. The rollers 15 have a pitch secured by a cage 16.

Next, the effect of the present invention will be described with reference to FIG. In the conventional slide bearing system, the friction loss is large and the mechanical efficiency ηm'31 is about 40% at the rotation speed of 3000 rpm, but the mechanical efficiency ηm32 reaches about 75% and the machine efficiency of about 35% by the rolling bearing system of the present invention. Achieved improved efficiency.

[0009]

The present invention has the following effects by being configured as described above. That is, since it is configured as in claim 1, it can be driven with stable low frictional force regardless of the type of fluid, temperature and pressure, and high efficiency can be achieved, and problems such as seizure due to dust and air inclusion can be avoided. It is possible to lose it. Further, since it is configured as in claim 2, it is possible to configure a small-sized and high-performance internal gear pump without increasing the outer dimensions.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a rolling bearing type internal gear pump.

FIG. 2 is a sectional view of a conventional slide bearing type internal gear pump.

FIG. 3 is a performance test result of a rotor pump (internal gear pump).

[Explanation of symbols]

 11/21 Drive shaft 12/22 External gear 13/23 Internal gear 14 Casing 15 Roller 16 Cage 24 Casing 25 Rotation direction 26 Suction port 27 Discharge port

Claims (2)

[Claims] 1. A bearing structure for an internal gear pump in which a rolling bearing is installed on the outer periphery of a driven internal gear of the internal gear pump. 2. A bearing structure for an internal gear pump, wherein the driven internal gear of the internal gear pump is an inner ring of a rolling bearing, and the casing is an outer ring of a rolling bearing.