JPH0385389A - Multifunction pump - Google Patents

Abstract

PURPOSE:To improve the pump performance by forming a plastic film layer on the outer circumference of a rotor, and correcting a clearance at the minimum between seals due to a plastic change caused by initial conforming of the film layer with a pump housing even if there are dispersion in accuracy of parts. CONSTITUTION:A film layer 51 having uniform thickness is formed on the outer circumference of a rotor 17, and the rotor is fitted to in a pump housing 10 to be rotated, the film layer 51 is thereby pressed in contact with the inner circumference of the pump housing 10 in the interval of seal 50, the thickness of the film layer 51 is conformed to the inner circumference of the pump housing 10 to keep the clearance in the interval 50 of the seal at the minimum. In case that the central offset volume of the center of the rotor 17 fitted to the normal eccentric center of the rotor relative to the pump housing 10 exists caused by the dispersion, etc. of the accuracy of the outer diameter and the inner diameter of the pump housing, the layer of the film layer 51 is plastically changed to t1-t2 so that the outer circumference of the film layer 51 becomes a concentric circle relative to the rotational center of a rotor 17 to correct central offset volume.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a multifunctional pump in which a vacuum pump and a compressor are arranged on the same rotation plane.

<Prior Art> A multifunctional pump is known in which a plurality of vanes are slidably provided in the radial direction at equal intervals on the circumference of a rotor that rotates eccentrically within a pump housing, and a compressor and a vacuum pump are arranged on the same rotation plane. It is.

<Problems to be Solved by the Invention> In this type of multifunctional pump, the outer periphery of the rotor is pushed inside the pump housing during low rotations when the vane ejecting force due to rotational centrifugal force in the compressor region is smaller than the vane pushing force due to compressor pressure. In the seal section where the volume of the pump chamber changes from contraction to expansion, pressure leaks from the tip of the vane to the vacuum side, reducing vacuum performance. In order to prevent this, it is necessary to manage the clearance between the outer circumference of the rotor and the inner circumference of the pump housing in the seal section, but take into account variations in accuracy such as the rotor outer diameter, pump housing inner diameter, and rotor eccentricity. This requires extremely precise tolerances, and the clearance management is extremely difficult.

Means for Solving the Problems> The present invention has been made in view of the above-mentioned problems, and includes a rotor rotatably housed in a pump housing, and a plurality of vanes arranged around the circumference of the rotor. The crescent-shaped space formed between the pump housing and the rotor is divided into a plurality of pump chambers on the circumference by the vanes, and the volume increases as the rotor rotates. A vacuum suction port is opened at the starting end of the pump chamber, a compressor suction port is opened at the terminal end of the expansion pump chamber, and a compressor discharge port is opened at the terminal end of the contraction pump chamber whose volume decreases due to rotation of the rotor. In the pump, a plastic coating layer is formed on the outer periphery of the rotor.

Effect> With the above configuration, when the rotor is assembled into the pump housing and rotated, the coating layer is pressed against the inner circumferential surface of the pump housing in the seal section, and the coating layer is caused by misalignment of the center of the rotor with respect to the center of rotation. The membrane thickness adapts to the pump housing and changes plastically, keeping the clearance of the seal section to a minimum.

<Example> Hereinafter, an example of the present invention will be described based on the drawings. 1G
indicates a pump housing, and this pump housing 10
The housing comprises a center housing 12 having a hollow hole 11 formed therein, and a pair of side housings 13 and 14 bolted to both sides of the center housing 12. A rotary shaft 15 passing through the hollow hole 11 is rotatably supported on the side housing 13, 14 about an axis offset by a predetermined amount from the axis of the hollow hole 11. The rotating shaft 1
A rotor 17 is concentrically mounted on the rotor 5, and the rotor 17 is rotatably housed within the hollow hole 11.

A plurality of vane grooves are formed in the radial direction on the circumference of the rotor 11 at equal angular intervals on the circumference, and each vane 18 is slidably held in each of these vane grooves. Both ends of the rotor 17 and the vanes 18 are slidably opposed to the inner surface of the side housing 13, 14 with appropriate side clearance.

Annular grooves 17A and 17B are formed on both sides of the rotor 17, and rings 21 and 22 can float in the radial direction when the vane is pressed into these annular grooves 17A and 17B.
and is rotatably stored. Vane pressing is ring 2
The outer periphery of 1.22 contacts both sides of the inner ends of the plurality of vanes 18, pressing the vanes 18 against the inner surface of the hollow hole 11.

A crescent-shaped space is formed between the hollow hole 11 and the rotor 17, and this space is circumferentially divided into a plurality of pump chambers 23 by a plurality of vanes 18. The volume of each pump chamber 23 changes with the rotation of the rotor 17. For example, when the rotor 17 rotates in the direction of the arrow in FIG.
Based on the seal section 50 where the outer periphery of the rotor 17 contacts the inner peripheral surface of the center housing 12, the volume of each pump chamber located in the lower half increases, and the volume of each pump chamber located in the upper half decreases. Hereinafter, each pump chamber located in the lower half will be referred to as an expansion pump chamber, and each pump chamber located in the upper half will be referred to as a contraction pump chamber.

A vacuum suction port 31 is opened at the starting end in the rotational direction of the expansion pump chamber, and a compressor suction port 32 is opened at the terminal end in the rotational direction of the expansion pump chamber. A compressor discharge boat 33 is opened at the rotational end of the contraction pump chamber. The vacuum suction port 31 is IN-connected to a vacuum tank (not shown), the compressor suction port 32 is connected to the atmosphere via an air breather (not shown), and the compressor discharge boat 33 is connected to an operating device (11M) not shown.

Further, the side housing 14 is provided with a drain port 41 and an oil storage space 42 in front of the drain port 41. Although not shown, the side housing 13
A lubricating port for lubricating the bearing portion of the rotating shaft 15 is separately provided, and a lubricating oil pump is connected to this port. Therefore,
When the lubricating oil that has lubricated the bearing is drained,
A part of it is stored in the oil storage space 42.

The present invention provides a multifunctional pump as described above, in which the rotor 1
A plastic coating layer 51 is formed on the outer periphery of 7.

The coating layer 51 is formed by, for example, chemical conversion treatment with phosphate or surface treatment with molybdenum coating.

In the configuration described above, when the rotor 17 is rotated in the direction of the arrow in FIG. Decrease. Now, if the pump chamber immediately after the volume changes from a decreasing action to an increasing action is 23A,
As the rotor 17 rotates, this pump chamber 23A is first opened to the vacuum suction boat 31, sucks air from the vacuum tank to perform a vacuum action, and then the pump chamber 23A passes through the vacuum suction boat 31 and is sealed. The pump chamber 2
The inside of 3A is maintained in a negative pressure state. When the pump chamber 23A opens to the compressor suction port 32, atmospheric air is sucked from the compressor suction boat 32 into the pump chamber 23A under negative pressure. Thereafter, the pump chamber 23^ shifts to a contraction pump chamber, and the air in the pump chamber 23A is compressed.

Therefore, the pump chamber 23^ is the compressor discharge boat 3.
3, compressed air is discharged from the compressor discharge boat 33.

In the above-mentioned pump action, the element for improving the performance of the bong 1 is that the clearance of the seal section 50 transitioning from the contraction pump chamber to the expansion pump chamber is minimized and sealed in an optimal state.

Therefore, in the present invention, by assembling and rotating the rotor 17 having a coating layer 51 with a thickness of - on the outer periphery inside the pump housing 1G, the coating layer 51 is formed on the inner circumferential surface of the pump housing 10 in the seal section 50. The coating layer 51
The film thickness adapts to the inner circumferential surface of the pump housing 10 and maintains the clearance of the seal section to a minimum.

In particular, due to variations in the accuracy of the rotor outer diameter and the pump housing inner diameter, the pump housing 10 as shown in FIG.
If there is a center deviation of the center 02 of the assembled rotor 17 with respect to the normal eccentric center 01 of the rotor 17, the thickness of the coating layer 51 will be reduced due to pressure contact with the inner circumferential surface of the pump housing 10. At tl-t2, the outer periphery of the coating layer 51 becomes concentric with the center of rotation of the rotor 17 through plastic change, correcting the center deviation and securing the seal section 50 at a minimum appropriate clearance.

<Effects of the Invention> As described above, according to the present invention, in a pump configured to perform vacuum and compressor functions within one rotational plane, a plastic coating layer is formed on the outer periphery of the rotor. Even if there is a certain degree of variation in the accuracy of each part, the clearance of the seal section can be corrected to the minimum due to plastic changes caused by the initial adaptation of the coating layer to the pump housing.
This has the beneficial effect of improving pump performance and also improving seizure resistance due to the lithium coated layer.

[Brief explanation of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is a sectional view;
FIG. 2 is a sectional view taken along the line ■--■ in FIG. 1, and FIG. 3 is an explanatory diagram of the operation of the main parts of the present invention. 10... Pump housing, 11... Hollow hole, 15
... Rotating shaft, 17... Rotor, 18... Vane,
23...Pump chamber, 31...Vacuum suction boat, 33...Compressor discharge boat, 50...Seal section, 51...Coating layer. Patent Applicant Toyoda Koki Stock Figure 2 Figure 3

Claims (1)

[Claims] A rotor is rotatably housed in a pump housing, and a plurality of vanes are provided on the circumference of the rotor so as to be slidable in the radial direction. The space is circumferentially divided into a plurality of pump chambers, a vacuum suction port is opened at the starting end of the expansion pump chamber whose volume increases with rotation of the rotor, and a compressor suction port is opened at the terminal end of the expansion pump chamber. A multifunctional pump characterized in that a compressor discharge port is opened at the terminal end of a contraction pump chamber whose volume decreases as the rotor rotates, and a plastic coating layer is formed on the outer periphery of the rotor.