JPH0681955B2 - Gear pump - Google Patents

Description

TECHNICAL FIELD The present invention relates to a gear pump.

[Prior Art] In Figures 1 and 2 of German Patent Publication No. 1231563, a toothed rotor is arranged in an inner toothed annular body having one more tooth than that, and the rotor and the annular body are interlocked. A fixed displacement intermeshing gear pump adapted for rotation is disclosed.

British Patent No. 1426223 has a toothed annulus provided on an eccentric ring adapted to be driven by a rack and pinion, the axis of the annulus being displaced relative to the axis of the rotor. A gear pump is disclosed. When these two axes as well as the axis of the surface of the annulus are in a common plane, the pump is designed to exhibit maximum displacement. Therefore, the displacement is lowered by shifting the annular body from the maximum displacement position.

The discharge capacity of the pump also depends on the axial length of the rotating part. For example, the smooth operation of a pump, which is generally free of unwanted pulsation effects, depends on the number of teeth on the rotor as well as the annulus.

In European Patent Application No. 0076033A, two annular bodies are arranged in the axial direction, the two annular bodies are engaged with a common pinion, and the annular bodies are opposed to each other in the tooth combination of each annular body and the pinion. A gear pump adapted to rotate is disclosed. This gear pump can adjust the discharge capacity in the same way as the above-mentioned British patent,
Moreover, since the phase of the teeth of each annular body can be made different from each other, smooth and pulsation-free output was expected. However, the pump arrangement of this European patent application was found to be inoperable.

Problem to be Solved by the Invention It is an object of the present invention to enable the pump of the above European patent.

[Means for Solving the Problems] According to the present invention, each eccentric ring has a pair of annular bodies with internal teeth arranged in the axial direction, and the pair of annular bodies has one rotor. , And the eccentric ring is engaged with one pinion in common and rotated in opposite directions to change the eccentricity of the annular body and change the pump discharge capacity. In the gear pump configured as described above, there is provided a gear pump characterized in that each eccentric ring described above is supported at its outer periphery by a roller bearing.

Furthermore, a needle roller bearing is preferably used as the above roller bearing.

[Operation] The present invention has found that the gear pump described in the above-mentioned European Patent Application No. 0076033 causes a trap, which causes the gear pump to be inoperable, and this trap causes the eccentric ring to have a pump housing bore. This is done based on the recognition that it is caused by the addition of a force that makes it difficult to insert. Originally, this type of pump was soaked in oil to operate, so that the surfaces of pump components were sufficiently lubricated, and it was very difficult to recognize such a catch.

With the above configuration of the present invention, the cause of such a catch is eliminated, so that the gear pump operates smoothly,
Therefore, a gear pump having reliable operation is provided.

Embodiments The present invention will be described in detail in the form of preferred embodiments with reference to the accompanying drawings.

In the accompanying drawings, the internal structure of the gear pump is illustrated in a state where a cover plate (not shown) fixed at a fixed position by screwing a screw into the screw hole 10 is removed from the pump housing. Rotor 12 inside
Has an outer toothing of n teeth, for example 6, which meshes with an inner toothing of an annular body, for example 7, n + 1 teeth. This one rotor 12 is adapted to be rotated on a shaft 14 and two similar annular bodies 16, 18 are
It is provided so as to surround the rotor and to be aligned in the axial direction.
The annular bodies 16 and 18 are arranged in the eccentric rings 20 and 22, respectively, and the outer circumferences of the eccentric rings 20 and 22 are provided with gear teeth that mesh with one pinion 24 in common. By driving this pinion 24 by the rack 30, the eccentric ring 2
By rotating 0 and 22 in opposite directions, the eccentricity of the shafts of the annular bodies 16 and 18 with respect to the shaft of the rotor 12 is changed.

A needle roller bearing 40 is annularly arranged between the eccentric ring 20 and the pump housing, and also has an eccentric rung 22.
A needle roller bearing 40 is also arranged annularly between the pump housing and the pump housing. The needle roller bearing 40 on the side of the eccentric ring 22 has its axial displacement stopped by the pump housing, and the needle roller bearing 40 on the side of the eccentric ring 20 has its axial displacement stopped by the cover plate (not shown). If there is enough space for mounting, install lips or flanges at the ends of the eccentric rings 20 and 22 adjacent to the pump housing and cover plate so that the shaft of the needle roller bearing 40 is within the axial length of the eccentric rings 20 and 22. It can be held in the direction.

[Brief description of drawings]

The accompanying drawings are perspective views showing a gear pump according to an embodiment of the present invention. 10 …… Screw hole 12 …… Rotor 14 …… Shaft 16, 18 …… Annular body 20, 22 …… Eccentric ring 24 …… Pinion 30 …… Rack 40 …… Needle roller bearing

Claims (2)

[Claims] 1. A pair of annular bodies (16, 18) arranged in the eccentric rings (20, 22) and arranged in the axial direction, respectively. Is one rotor (1
2) is commonly held, the outer teeth of the rotor (12) and the inner teeth of the pair of annular bodies (16, 18) are in mesh with each other, and the outer teeth of the eccentric ring (20, 22) are In a gear pump which is adapted to be in common engagement with two pinions (24) and rotated in opposite directions to change the eccentricity of the annular bodies (16, 18) to change the pump discharge capacity, A gear pump characterized in that the eccentric rings (20, 22) are supported at their outer circumferences by roller bearings (40), respectively. 2. The gear pump according to claim 1, wherein the roller bearing (40) is a needle roller bearing.