JPS614876A - Closed type motor driven compressor - Google Patents

Abstract

PURPOSE:To improve the volume efficiency of a compressor while prevent a liquid refrigerant from being directly sucked into a suction muffler and secure the reliability of a compressor by allowing a return gas refrigerant to be directly sucked into said suction muffler without receiving the effect of heat. CONSTITUTION:A motor element 2 and a compressing element 3 are provided in a closed skin 1. And, a suction gas introducing passage 12 is fixed to the closed skin 1. This introducing passage 12 consists of a suction pipe 13 which rises up inside, a close-contact coil spring 14 which is made of a wire member wound into a cylindrical coil state and whose bottom end is pressed into the suction pipe 13, a connecting pipe 15 which is pressed into this spring 14, a coil spring 16 consisting of a two-directional shape remembering alloy and which is pressed into one end of the connecting pipe 15, and a suction muffler 17 into which the spring 16 is inserted. Thereby, the introduction passage 12 is separated from heat generated by the motor element 2 and the compressing element 3. Accordingly, a suction gas is directly sucked into the suction muffler 17 without being exposed to a high temp. atmosphere.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a hermetic electric compressor for refrigerators, freezers, showcases, etc.

Conventional configuration and its problems It has been known to introduce suction refrigerant gas directly into the compression element in order to improve the volumetric efficiency of the compressor. If the piping is sealed to the suction muffler or cylinder head, when the liquid refrigerant returns from the evaporator, it will be sucked in and compressed, causing fatal problems for the compressor such as abnormal noise, gasket rupture, and vane breakage. Occurred.

Purpose of the Invention The present invention eliminates the problems of the above-mentioned conventional example,
The purpose is to improve the reliability of a hermetic electric compressor that has a structure in which refrigerant gas is guided directly from a suction pipe to a cylinder via a suction muffler.

Invention composition book. In order to achieve the above-mentioned object, the invention provides a series of suction pipe components that include the following steps:
The muffler is equipped with a coil spring made of a bidirectional shape memory alloy that remains in close contact above a predetermined temperature and extends to a predetermined length below a predetermined temperature, to prevent liquid refrigerant from being sucked into the muffler.

Description of examples An embodiment of the present invention will be described below.

In FIG. 1, 1 is an upper case 1a1 a lower case 1b.
The hermetic jacket of an electric compressor consists of: Reference numeral 2 denotes an electric element composed of a stator 4, a rotor 6, and a crankshaft 6 directly fixed to the rotor 6. 3 is a cylinder head 7, a cylinder 8. Piston 9. and a compression element constituted by a connecting rod 10 and the like connected to the eccentric portion 11 of the crankshaft 6. Electric element 2 starts and crankshaft 6
rotates, its eccentric portion 11. As is well known, the piston 9 reciprocates within the cylinder 8 by the movement transmitted through the connecting rod 1°, and sucks in, compresses, and discharges refrigerant gas. 12 is a suction gas introduction passage, and a sealed envelope 1
A suction pipe 13 that is fixed to the suction pipe 13 and rises upward from the inside, a close coil spring 14 whose lower end is press-fitted and fixed to the suction pipe 13 and made into a cylinder by winding a wire into a coil, and a close coil spring 14 that is press-fitted and fixed to the upper end of the close coil spring 14. a coil spring 16 made of a bidirectional shape memory alloy having a transformation point at a predetermined temperature and press-fitted into one end of the connecting pipe 16;
The suction muffler 17 has a spring stiffness that can support the coil spring 16 made of alloy. Further, the coil spring 16 made of the shape memory alloy and the inlet hole 17a of the suction muffler 17 are fitted with a minimum clearance that allows sliding.

In the above configuration, the suction gas introduction path 12 is connected to the suction pipe 13
, close coil spring 14, connecting pipe 15, coil spring 16,
They are connected by a suction muffler 17 and are isolated from the heat generated from the electric element 2 and compression element 3 within the hermetic envelope 1. Therefore, the suction gas is directly sucked into the suction muffler 17 without being exposed to the high temperature atmosphere. In this case, since the gas returned from the evaporator is generally at 0°C or higher, the transformation point of the shape memory alloy is set at 0°C, that is, the shape memory alloy is in a close contact state at 0°C or higher. Furthermore, when the liquid refrigerant returns from the evaporator, it passes through the same suction path as the gas refrigerant described above, but since the temperature of the liquid refrigerant that returns is usually below 0°C, the coil spring 16 made of a shape memory alloy is heated at 0°C.
Below, it is stretched to a predetermined length. Therefore, the liquid refrigerant leaks through the gap between the coil springs made of shape memory alloy,
The amount of direct suction from the suction muffler 17 is reduced, and the reliability of the compressor is ensured.

Effects of the Invention The present invention has the above-described configuration, and provides the following effects.

An electric element and a compression element elastically supported within a hermetic envelope, a suction pipe penetrating the hermetic envelope, a muffler fixed to the compression element, and inserted into an inlet hole of the muffler with a slight gap. A coil spring that guides the refrigerant from the suction pipe, which is made of a bidirectional shape memory alloy that is in close contact above a predetermined temperature and extends to a predetermined length below a predetermined temperature, allows the return gas refrigerant to be teeth,
The volumetric efficiency of the compressor is improved by being sucked directly into the suction muffler without being affected by the heat of the compressor.
Furthermore, since the liquid refrigerant stretches the coil spring due to its temperature, it leaks through the gap between the coil springs, so that the reliability of the compressor can be ensured without being directly sucked into the suction muffler.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a hermetic electric compressor showing an embodiment of the present invention, and FIG. 2 is a sectional view of the same as seen from the muffler side of FIG. 1. 1... Sealed envelope, 2... Electric element, 3
... Compression element, 13 ... Suction pipe, 15
...Connecting pipe, 16... Coil spring, 1
7...Suction mimuffler. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2!

Claims (1)

[Claims] An electric element and a compression element elastically supported within the hermetic envelope, a suction pipe passing through the hermetic envelope, a muffler fixed to the compression element, and inserted into the inlet hole of the muffler with a slight gap. A hermetic electric compressor comprising a coil spring that guides refrigerant from the suction pipe made of a bidirectional shape memory alloy that is in a sealed state above a predetermined temperature and extends to a predetermined length below a predetermined temperature.