JPS61118589A - Electric compressor - Google Patents

Abstract

PURPOSE:To reduce energy loss due to stirring largely by burying to form a balance weight member whose specific gravity is larger than that of a material forming a rotor in the rotor at the lower end portion of the rotor and by reducing resistant force applied to the balance weight. CONSTITUTION:A balance weight member 26 whose specific gravity is larger than that of a material forming a rotor 27 is inserted in a concave 30 provided on an end face of the rotor 27 and fixed with a bolt 31 to form the rotor 27 whose projection unit is eliminated apparently. Then, the front surface area of the balance weight member 26 becomes zero and theoretical resistant force becomes zero. With such a balance member 26 burying type rotor 27, resistant force applied to the balance weight 26 can be minimized and energy loss due to stirring can extremely be reduced, and efficiency of a compressor can be raised.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an electric compressor used as a refrigeration compressor for refrigeration and air conditioning, or as a compressor for air or other gases.

Conventional configuration and its problems Taking a vertical oil-fed scroll compressor for refrigeration and air conditioning as an example,
The basic configuration will be explained with reference to FIGS. 1 and 2. First, the operating principle of a scroll compressor will be explained with reference to FIG. In the spiral orbiting scroll 1 and fixed scroll 2, when the orbiting scroll 1 is rotated clockwise, the wrap 1a and end plate (not shown) of the orbiting scroll 1 and the wrap 2a and end plate of the fixed scroll 2 are Compression chambers 3 (3a, 3b) formed by (not shown)
.

...), the refrigerant gas sucked into the compression chambers 3a and ab located on the outermost side from the suction port 4 is hermetically sealed. Further, the volumes of the compression chambers 3a and 3b gradually decrease as the orbiting scroll 1 rotates, and the refrigerant gas increases in pressure and is discharged from the central discharge port 6.

Next, the basic configuration of a conventional scroll compressor will be explained with reference to FIG.

A fixed scroll 2 having a spiral wrap 2a standing upright on an end plate 2b, and an orbiting scroll 1 having substantially the same shape as the fixed scroll 2 and consisting of a wrap 1a and an end plate 1b.
and engage each other with wraps 1a and 2a inside,
Further, a rotation prevention mechanism called an Oldham ring 8 is provided between the frame 7 fastened to the fixed scroll 2 and the orbiting scroll 1. A rotor 11a of an electric motor 11 is joined to a crankshaft 1o that is rotationally supported by a bearing 9 of a frame 7, and the crankshaft 10 is rotationally driven by a stator 11b held in the frame 7 or a closed container 12. .

by the way. The orbiting scroll 1 rotates around the central axis of the bearing section 9 of the frame 7 with its end plate 1b sandwiched between the mirror plate section 2C of the fixed scroll 2 and the pedestal 13 of the frame 7. The crankshaft 10 has an eccentric shaft 10' having an eccentric amount ε, and this eccentric amount e becomes the orbiting radius of the orbiting scroll 1. Further, the crankshaft 10 and the rotor 11a are provided with a quaternary balance weight 1 for offsetting the centrifugal force generated by the orbiting scroll 1 and the eccentric shaft 10'.
4 and a secondary balance weight 14' are provided in engagement. The scroll compressor shown in FIG. 2 is an example of a structure of an internal high pressure type in which the inside of the closed container 12 is in an atmosphere of discharge pressure (high pressure side pressure).

Next, the operation of the compressor will be explained according to the flow of refrigerant gas and the flow of lubricating oil.

Low-pressure refrigerant gas is led from the suction pipe 16 and from the suction port 4 of the fixed scroll 2 to the fixed scroll 2 and the orbiting scroll 1.
This leads to a compression chamber 3 formed by. The refrigerant gas that has entered the compression chamber 3 is gradually compressed by the orbiting (revolution) movement of the orbiting scroll 1 as described in the operating principle and moves to the center of the scroll, increasing the pressure and passing through the central discharge port 6.
It is discharged into the closed container 12. The discharged high pressure is guided to the outside from the cold discharge pipe 19.

Next, the flow of the lubricating oil 20 will be explained. The lubricating oil 2Q is stored in the lower part of the closed container 12, and the lower end of the crankshaft 10 immersed in the lubricating oil 20 is in an atmosphere of high discharge pressure. A vertical hole 21 is formed in the crankshaft 10 from the lower end to the upper end surface for supplying oil to the bearing and sliding parts of the upper compression mechanism.

The lubricating oil 2o accumulated in the lower part of the closed container 12 is in a compressed high-pressure gas atmosphere, and due to the pressure, it moves up the vertical hole 21 of the crankshaft 10 and passes through the gap between the bearing part 9 and the orbiting bearing 22 to the orbiting scroll 1. It further leaks into the low-pressure side of the compression chamber 3 through the gaps between the end plate 1b of the orbiting scroll 1, the end plate 2c of the fixed scroll 2, and the pedestal 13 of the frame 7. The lubricating oil that has leaked into the compression chamber 3 is compressed together with the refrigerant gas through the discharge port 62 and the passage 17.
The oil then moves to a wide space at the bottom of the closed container 12, and due to the rapid decrease in flow velocity, the oil falls to the bottom of the container under its own weight and accumulates. In other words, the lubricating oil 2o is an oil supply and a heat source.

Separation and accumulation are repeated.

Next, conventional problems will be explained with reference to FIGS. 2, 3, and 4. As shown in FIGS. 2 and 3, the secondary balance weight 14' is engaged with the lower end of the rotor 11a of the electric motor 11, and is immersed in the lubricating oil 20 collected at the bottom of the closed container 12.

This secondary balance weight 14' swings around the crankshaft 10 as the rotor 11a rotates. When the secondary balance weight 14' is immersed in the lubricating oil 20 and rotated in this way, as shown in FIG. 5, by stirring the oil, a vortex 24 is created in the wake of the secondary balance weight 14'. This causes a large loss of energy.

This energy loss is proportional to the resistance force experienced by the secondary balance weight 14' rotating in oil. Furthermore, the magnitude of this resistance force is determined by the density of the lubricating oil 20, the front surface area 26 of the secondary balance weight, and the peripheral speed of the secondary balance weight.
It is roughly proportional to the power of

Therefore, in recent years, there has been a tendency for compressors to increase their rotational speed through frequency conversion, etc., and the above-mentioned resistance force has a large effect on the performance of the compressor.

OBJECTS OF THE INVENTION In view of the above problems, the present invention provides a rotor with a balance weight that reduces loss due to stirring.

Structure of the Invention In order to achieve the above object, the present invention has an unbalanced part embedded in a part of a cylindrical rotor to form a motor rotor with no apparent protrusion, which reduces the resistance caused by stirring. It has the characteristic of reducing force.

DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to FIGS.

FIG. 6 shows an embodiment of a rotor 27 provided with a waist member 26 corresponding to the secondary balance weight 14' of the conventional example. Generally, the structure of the rotor 27 is often one in which disc-shaped steel plates 28 are stacked and aluminum 29 is pressed and hardened between them. The rotor 27 is formed by embedding a weight member 26 having an appropriate weight when the aluminum 29 is solidified. At this time, it goes without saying that a mark is placed on the surface so that the buried position of the weight member 26 can be determined from the appearance in consideration of the time of assembly.

FIG. 6 shows a rotor 27 in which a weight member 26 is inserted into a recess 30 provided on the end face of the rotor 27 and fixed with a bolt 31, and the rotor 27 has no protrusions in appearance.

In any of the above embodiments, the shape of the rotor 27 is such that there is no protrusion, and the balance weight The front surface area of the image becomes zero, and the theoretical resistance force also becomes zero.

Therefore, according to this embodiment, loss due to stirring can be completely eliminated.

As a detailed description of the invention, by using the rotor of the balance member embedded type according to the present invention, the resistance force applied to the balance weight can be reduced, and the energy loss due to stirring can be significantly reduced, and the efficiency of the compressor can be improved. can be increased.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing the meshing state of the scrolls, Figure 2 is a vertical cross-sectional view of a conventional hermetic scroll compressor, and Figure 3 is a vertical cross-sectional view of a conventional hermetic scroll compressor.
The figure is a perspective view of a rotor equipped with a conventional secondary balance weight, Figure 4 is a cross-sectional view of the rotor in Figure 3 taken along line AA, showing the flow pattern of lubricating oil around it, and Figure 6. 6 is a vertical cross-sectional view of a rotor showing one embodiment of the present invention, and FIG. 6 is a vertical cross-sectional view of a rotor showing another embodiment of the present invention. 1...Turning, ', crawl, 2...Fixed scroll, 10...Crankshaft, 11 a
, 27...Rotor, 14'...Secondary balance weight, 20...Lubricating oil, 26...
...Weight member. Name of agent: Patent attorney Toshio Nakao and 1 other person 1st
Figure 3 Figure 4 Dohaya Figure 5 Figure 6

Claims (1)

[Claims] A compression mechanism that has a fixed scroll and an orbiting scroll and compresses gas by the relative movement of both scrolls, and an electric motor that drives this compression mechanism are arranged in a closed container, with the compression mechanism in the upper part and the electric motor in the lower part. An arc-shaped balance weight is attached to the lower end of the rotor of the electric motor, and the oil at the bottom of the sealed container is supplied to each sliding part of the compressor through the shaft of the electric motor. An electric compressor characterized in that a balance weight member having a higher specific gravity than a material forming a rotor or a part of the rotor is embedded in the lower end portion of the rotor.