JPH02157491A - Volumetric pump - Google Patents

Abstract

PURPOSE:To display a self-aligning function without degrading pump capacity even if a bearing load is increased, by providing an annular cavity concentric or eccentric with a bearing surface and having one end closed and the other end opened in a bearing to allow pump pressure to act the opened surface. CONSTITUTION:A bearing 11 is provided with an annular cavity 31 concentric with a cylindrical bearing surface 30 and having one end closed and the other end opened to the space side on which pump pressure acts. Further, a wall thickness between the bearing surface 30 and the cavity 31 is selected to have a self-aligning property according to the load and material of the bearing 11. Thus, even if the load on the bearing is increased and the pump pressure is heightened to increase the load, the self-aligning function can be displayed without degrading the pump capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to improving the bearing performance of a positive displacement pump bearing.

BACKGROUND OF THE INVENTION Conventionally, bearings used in this type of positive displacement pump have been constructed by attaching a flat bearing to the inner wall of a pump case via an elastic ring, as shown in, for example, Japanese Utility Model Application Publication No. 50-65002. This is an attempt to provide alignment to the bearing.

Problems to be Solved by the Invention However, with such a structure, the number of parts in the bearing increases, assembly errors occur in the assembly of the bearing, and when the bearing load increases, the bearing displaces in the load direction. There is a problem of deteriorating pump performance.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to simplify the structure of a bearing having alignment and to change the alignment of the bearing in accordance with the load capacity of the bearing.

Means for Solving the Problems In order to achieve the above object, the present invention provides a bearing with an annular hollow portion concentric with the cylindrical bearing surface or slightly eccentric, with one end closed and the other end open. Pump pressure is applied to the opening surface of the

Function The positive displacement pump of the present invention has a hollow portion that reduces the rigidity of the cylindrical bearing surface of the bearing to provide alignment, and when the pump pressure increases and the bearing load increases, The pump pressure introduced into the cavity increases the rigidity of the bearing surface, maintains the positional accuracy of the bearing, and does not reduce pump performance.

Embodiments Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. In Figures 1 to 4, l is a pump case;
The inner surface thereof is a pump space 2 formed in a cylindrical shape, a cylindrical space 3 provided at the bottom of the pump space 2, and a cylindrical space 5 communicating with a through hole 4 at the bottom of the cylindrical space 3.
The cylindrical space 5 is formed by a flange 6 that forms a coupling surface with the motor. A step 1a is formed on the opening surface of the pump space 2, and an O-ring 7 is inserted therein. An oil seal 8 is inserted into a cylindrical gap 3 provided at the bottom of the pump space 2 . The rotor case 9 is first inserted into the pump space 2 . The rotor case 9 is constructed by integrally molding a cylindrical cam surface 10 and a side plate A12 having a bearing 11 that is eccentric from the cam surface 10 by a predetermined amount and a flat portion 12a that seals one end surface of the cam surface 10. ing. Here, since there is a slight gap between the rotor case 9 and the pump space 2, the rotor case 9 and the pump space 2 can be easily inserted.

The rotor 13 is composed of a rotating body 16 having a groove 15 for slidably holding a cylindrical vane 14, and a main shaft 17 coaxially formed integrally with the rotating body 16, and cantilevered by a bearing II of the rotor case 9. Rotatably supported in a support configuration. The pump space 2 is sealed via the O-ring 7 in the pump 1i18a. The pump 1118 has a disc-shaped recess 18b, into which a lid sliding plate 21 is inserted via a gasket 20. l! The sliding plate 21 is connected to the side plate B12 together with the side plate A12.
b and is fixed to the rotor 13 at a minute interval. The lid sliding plate 21 has 1. There is a suction boat 22 and a discharge boat 23, which communicate with a suction port 24a and a discharge port 24b provided in the pump lid 18, respectively. The lid sliding plate 21 is the packing 2
It is pressed against the end face of the rotor case 9 by the elasticity of 0,
The lid sliding plate 21 and the rotor case 9 are kept airtight. Pump pressure acts on the space 9a formed by the lid sliding plate 21 and the rotor case 9.

Next, a method of coupling the ζ pump section and the motor section will be described. In positive displacement pumps, it is necessary to pay attention to misalignment of the drive shaft system, and in the pump of the present invention, a flexible jist is used. Reference numeral 25 denotes a spring joint, which is composed of a pair of flanges 26a and 26b having a D cut and a cylindrical spring 27 whose ends are fixed to the flanges 26a and 26b, respectively, and the flange 26a is connected to the main shaft 17 of the rotor 13. . The motor 2B is press-fitted into the flange 6 of the pump case 1, and is fixed to the pump case l with pump fixing screws.

Further, the rotating shaft 29 of the motor 28 and the flange 26b are fixed at the same time.

Further, the bearing 11 is provided with an annular cavity 31 concentrically with the cylindrical bearing surface 30, and one end of this cavity 31 is closed.
The other end is open to the space where pump pressure acts. The wall thickness between the bearing surface 30 and the cavity 31 needs to be selected depending on the load and material of the bearing 11 so that the bearing 11 has appropriate alignment.

Next, the operation of this embodiment will be explained. Rotor 13
The coaxiality and perpendicularity between the rotating body 16 and the main shaft 17, as well as the perpendicularity between the flat part 12a of the rotor case 9 and the bearing surface 30, are machined to the required accuracy, but from the perspective of fluid lubrication. This lacks precision, and a bearing misalignment correction function is important. In this embodiment, since the bearing surface 30 has a hollow portion 31, the rigidity on the opening 31a side of the hollow portion 31 is low, and the rigidity on the closing portion 31b side is high, so that it is resistant to prying of the main shaft 17. be able to respond effectively.

Furthermore, when the pump pressure increases and the load on the bearing 11 increases, the pump pressure also acts on the cavity 31, increasing the bearing rigidity and preventing excessive deformation of the bearing 11.

In addition, when the bearing 11 is made of a resin molded product, the vicinity of the bearing surface 30 is made of thin and uniform resin, so that high-precision resin molding is possible.

Effects of the Invention As described above, the present invention improves the alignment of the bearing of a positive displacement pump.
Since it has a means to change according to the load capacity of the bearing,
Even if the pressure of the positive displacement pump is high and the load on the bearing increases, the bearing alignment function is achieved without reducing pump performance.

[Brief explanation of the drawing]

FIG. 1 is an exploded cross-sectional view of parts of a positive displacement pump showing an embodiment of the present invention;
6: is a front view of the same, Figure 3 is a plan view of the main part of the pump, Figure 4 is
The figure is a sectional view of the coaxial bearing part. 11...Bearing, 30...Bearing surface, 31
...Cavity part, 31a...Opening part, 9a
・・・・・・Space where pump pressure acts. Name of agent: Patent attorney Shigetaka Awano (1 person)

Claims (1)

[Claims] The bearing is provided with an annular cavity concentrically or eccentrically with the cylindrical bearing surface, with one end closed and the other end open, at a location larger than the diameter of the bearing surface, and the opening of the cavity is used as a pump. A positive displacement pump that opens into a space where pressure acts.