JPH01224482A - Motor-driven compressor - Google Patents

Abstract

PURPOSE:To suppress drop of the efficiency of a compressor and also drop of the oil system capacity by furnishing a boss in the form of an arc of circle molded in a single piece with an end ring, and constructing so that a balance weight and this boss constitute a consolidated ring. CONSTITUTION:A boss 11 provided on an end ring 6 is made with approx. the same inner and outer dias. and height as a balance weight 7, and the end faces of these two in circumferential direction contact each other to constitute approx. one consolidated ring. Agitation of lubricating oil by the balance weight 7 can be reduced remarkably compared with the case where no boss 11 is provided on the end ring 6. This can suppress drop of the efficiency of compressor and also drop of the oil system capacity.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric compressor used in refrigeration air conditioners, refrigeration showcases, and the like.

Conventional technology The basic configuration thereof will be explained with reference to FIG.

The compressor is composed of a compression mechanism section 1 that controls refrigerant compression, an electric motor section including a stator 2 and a rotor 3, and a drive shaft 4 that connects the two sections, which are housed inside a closed container 5. be done.

A balance weight 7 made of a metal material with high specific gravity such as iron or brass is fixed on the end ring 6 on the anti-load side of the rotor 3.

Further, lubricating oil 8 is stored in the lower part of the closed container 5.

The operation of the compressor configured as above will be explained.

The low-temperature, low-pressure refrigerant gas is led from the suction pipe 9 to the compression mechanism section 1, and is compressed within the compression mechanism section 1 by the rotational power of the electric motor to become a high-temperature, high-pressure gas, which is then discharged into the sealed container 5 and then passed through the discharge pipe. 1o into the system.

The lubricating oil lv8 is supplied to the compression mechanism section 1 by a differential pressure oil supply method, but in some cases, a centrifugal pump method or other type of oil supply method is used.

Further, the balance weight 7 of the rotor 3 works in combination with a balancer provided in the compression mechanism section 1 to suppress vibrations of the compressor due to compression operation.

Problem to be Solved by the Invention However, in the compressor configured as described above, the oil level of the lubricating oil IVB during normal operation is at the level A in Fig. 3, but depending on the conditions, it may rise to the level B. In some cases, the balance weight 7 or end ring 6 may be immersed in the oil.

In other words, after a certain period of time has passed after the operation is stopped, the refrigerant becomes lubricating oil/I.
/8 When the oil level is pushed up by melting into the oil or separating into two layers, when the compressor temperature becomes lower than the condensing temperature and the same condition as above occurs, or when the oil is driven by an Everter at high speed. In order to prevent oil shortage, the oil level often rises until the balance weight 7 is immersed, such as when operating at low speed with the initial amount of lubricating oil /L/8 increased.

On the other hand, since the balance weight 7 is formed in an arc shape, it partially protrudes above the end ring θ. Therefore, due to the rotation of the rotor 3, the balance weight 70
The circumferential end surface will agitate the immersed lubricating oil.

This oil agitation causes agitation loss, which increases the input to the motor and reduces the efficiency of the compressor.The lubricating oil/I/8 is also discharged to the external system through the discharge pipe 1o, which increases the system capacity. This causes a decrease in

The present invention aims to solve the above-mentioned problems by suppressing the agitation of lubricating oil 8 by the balance weight 7 by providing an arc-shaped protrusion on the end ring 6. Means for Solving the Problems In order to solve the above problems, the present invention provides a circle that is set on the end ring to have approximately the same inner and outer diameters and height as the balance weight, and that is approximately in contact with both circumferential end surfaces of the balance weight. The present invention has a rotor structure in which an arc-shaped protrusion is integrally molded with the end ring, and the balance weight and the protrusion form an almost integral annular shape. By providing the protrusion, even if the balance weight is immersed in lubricating oil, the balance weight and the end ring protrusion have an almost integral annular shape, so the agitation of the lubricating oil is significantly reduced, and oil agitation is reduced. The reduction in compressor efficiency caused by this and the reduction in system capacity due to lubricating oil discharged into the system can be reduced to an extremely small degree.Example: An example of the present invention is shown in Figs. 1 and 2 below. Refer to and explain.

2 is a front view of the rotor shown in FIG. 1 as viewed from the balance weight side.

Further, the same parts as those in the conventional example are given the same reference numerals, and the description thereof will be omitted.

In FIGS. 1 and 2, the protrusion 11 provided on the end ring e is set to have almost the same inner and outer diameters and height as the balance weight 7, and both end surfaces in the circumferential direction are flush with each other. The ring is shaped so that it is almost in contact with the ring, so that the two form a substantially integral annular shape.

Therefore, the oil level of lubricating oil A/8 is equal to the balance weight 7.
Even when the lubricating oil rises to a level where it is immersed, the agitation of the lubricating oil by the balance weight 7 can be significantly reduced compared to the case where the end ring 6 is not provided with the protrusion 11.

In addition, by providing the protrusion 11 on the end ring 6,
The amount of balance weight of the rotor changes, but since the protrusion 11 is made of a conductive material with low specific gravity such as electrical aluminum that is integrally molded with the end ring 6, the height of the balance weight 7 is adjusted to the height of the protrusion 11. It can be easily corrected by adjusting the height while keeping it the same.

Furthermore, although FIG. 1 shows an example in which the compression mechanism section 1 and the electric motor section are connected in the vertical direction and the pressure inside the closed container is high, the compressor and the closed container have a structure in which the compressor and the closed container are connected in the horizontal direction. The same procedure can be applied to a compressor that produces low pressure.

Furthermore, the compression mechanism section 1 can be implemented in a reciprocating compression method as well as a rotary compression method.0 Effects of the Invention As described above, the present invention provides a rotor on the end ring with approximately the same inner and outer diameters and height as the balance weight. An arc-shaped protrusion that is set and substantially in contact with both circumferential end surfaces of the balance weight is integrally molded with the end ring, and the balance weight and the protrusion are configured to form a substantially integral annular shape. By adopting the rotor structure, even if the balance weight is immersed in lubricating oil, the oil agitation by the balance weight can be kept to a slight level. This has the effect of suppressing a decrease in compressor efficiency due to oil agitation loss and a decrease in system capacity due to oil discharge into the system.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a compressor showing an embodiment of the present invention, FIG. 2 is a front view of the rotor shown in FIG. 1 as viewed from the balance weight direction, and FIG. 3 is a longitudinal sectional view of a conventional compressor. 0 3... Rotor, 6... End ring,
7...°°°Balance weight, 11... Protrusion, 6 Fig. 2

Claims (1)

[Claims] On the end ring, an arcuate protrusion is integrally molded with the end ring and has an inner and outer diameter and a height that are almost the same as the balance weight, and is in contact with both end surfaces of the balance weight in the circumferential direction. An electric compressor having a rotor configured such that a balance weight and the protruding portion form a substantially integral annular shape.