JPS5993978A - Cooling device for end-turn of motor in compressor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an airtight motor compressor unit, and more particularly, to a gas-tight motor compressor unit, in which a portion of lubricating oil sucked up by a lubricating oil pickup pipe is transferred to a lower end turn of a motor stator.
d turns).

PRIOR ART One of the significant problems associated with airtight motor-compressor units is the heat generated by the operation of the unit, which impairs the cooling efficiency of the compressor. Therefore, various devices are arranged within the housing of the motor-compressor unit for pouring lubricating oil onto or towards other components from an oil sump provided within the housing.

An example of such a device is disclosed in US Pat. No. 3,618,337. The apparatus disclosed herein uses a portion of the aspirated lubricating oil to cool the lower end ring of the rotor and subsequently the lower end turn of the stator. Specifically, oil flows from the oil sump through the oil pickup pipe and into the chamber. The chamber is formed by the inner surface of the rotor end ring, a radially disposed flange on the pick-up tube, and the rotating crankshaft. Passages are provided radially in the end ring of the rotor through which oil in the chamber is dispersed toward and cools the lower end turn of the rotor. However, the lubricating oil must first pass through a passage in the rotor end ring before contacting the stator's lower end turn; as the lubricant passes through that radial passage, it heats up from the rotor end ring. The efficiency with which the lower end turns of the stator are cooled is reduced due to the loss of energy and increased temperature.

Furthermore, another drawback of the device disclosed in the above-mentioned US Pat. No. 3,618,337 is the increased cost resulting from the structure defining the oil chamber. That is,
Requires a rotor end ring, a radially disposed flange on the pickup tube, and a securing member for attaching the radial flange to the lower surface of the rotor end ring, as well as a plurality of radial passage holes in the rotor end ring. must be opened.

Another prior art similar to the prior art described above is disclosed in US Pat. No. 3,560,116. Here, the oil is pumped, creating two streams.

One flow is used for normal lubrication purposes associated with the parts located in the upper housing area, and the other flow is used directly to cool the motor parts. These two streams of oil are created by two oil pump pick-up tubes: an inner tube and an outer tube. The outer pipe I sends the lubricating oil upwardly into the suction chamber through a limited area between the outer pipe and the inner pipe.

The chamber is formed by the rotor's lower short-circuit ring, a radially disposed flange at the top of the outer tube, and an inner tube extending upward into the rotating crankshaft. The radial flange is provided with a plurality of radial groups of recesses which together with the lower surface of the lower shorting ring direct a portion of the lubricating oil towards the ends of the coils below the stator.

However, the cooling efficiency of the stator lower coil ends is still reduced. This is because the sprayed oil absorbs thermal energy from the radial flange, internal pickup tube, and rotor lower shorted ring. US Patent No. 3
618337, the rotor temperature is generally higher than the stator temperature, which further reduces the cooling effect of the oil toward the stator lower coil ends.

Furthermore, the cooling device in the above-mentioned U.S. Pat. It has an unfavorable l/X aspect which increases the cost of the compressor due to its rather complex structure requiring both groups.

[Object of the Invention] The cooling device according to the present invention obviates the above-mentioned conventional drawbacks and problems by providing a lubricating oil pick-up pipe with radially arranged holes; A portion of the lubricant is transferred upwardly from the sump through the lubricant pick-up tube and directly onto the radial inner surface of the lower end turn of the stator before contacting other components of the motor and losing heat. An object of the present invention is to provide an improved cooling system for an Ss type motor compressor unit that provides lubricating oil for the Ss type motor compressor unit.

It is a further object to provide an improved, inexpensively manufactured cooling system for the lower stator end turn of a hermetic motor compressor unit - the following detailed description of the invention is provided in the drawings. Through the description, the above-mentioned and other features and objects, as well as methods of obtaining them, will become clearer, and the invention itself will be better understood.

Embodiments of the Invention In one embodiment of the invention, a refrigeration system is provided within the airtight motor-compressor unit. The cooling system is formed by a lubricating oil pick-up tube, one end of which is connected to the rotating crankshaft, and the other end is connected to an oil sump located within the housing of the motor-compressor nine units. It's growing. The pipe has a shaft hole extending upwardly from the other end through which oil is sucked up from the oil sump.

The stator of the motor has lower end turns whose radial inner surfaces are bi-shaped.

It extends downward while being close to the cup tube in the radial direction and spaced apart from it in space. The pick-up tube is further provided with radial passage means communicating with the shaft bore and directly facing the stator lower end turn. When the lubricant pick-up tube is rotated, a portion of the lubricant sucked in three directions through the shaft hole passes through the radial passage means and is directly fixed before contacting other parts of the motor unit. The lower end turns are blown radially outward toward the radially inner surface.

Referring to the drawings, the lower part 2 of the hermetic motor compressor unit consists of an outer compressor housing 4 in which a rotor 6 is fixed to a rotatable crankshaft 8 and in the housing 4 a rotor 6 fixed to a rotatable crankshaft 8. A stator 10 fixed to the outer housing 4, an oil sump 12 provided below the outer housing 4, and a cooling device 14 according to the invention are housed. A crankshaft 8 is mounted within the AN, motor-compressor unit 2 and includes a plurality of axial passages 16, 18 .
20 are arranged. These passages 16, 18.20
The motor-compressor 9 is arranged to deliver oil to the upper components of the unit 2. Passage 16.18.2
A portion of the oil that is pumped upwardly through the sump 12 generally returns to the sump 12 by means of gravity. The rotor 6 has an end ring 22 and the stator lO has a stator motor end turn 24. The stator motor end turn 24 extends downwardly into the outer housing such that its lower end is below the oil level 26 of the sump 12.

The cooling device 14 consists of a pick-up tube z8, the pick-up tube 28 having a typically cylindrical central portion 30 and a central portion 3
0 and an upper part 34 arranged in the passage 16 of the crankshaft 8. As shown, the pickup tube 28 has an axial bore 36 therein and a passage 16 of the crankshaft 8.
I am in touch with you. The lower end of the shaft bore 36 has an opening 38 in the conical portion 32 and is located below the oil level 26.

The pick-up tube 28 is provided with radially disposed holes 40 through which a portion of the sucked up lubricating oil is radially blown outward. Important for the cooling device 14 is the hole 40 in the pickup tube 28.
is the axial position of

A hole 40 is provided in the pick-up tube 28 and is located within the radially disposed inner surface 4 of the stator end turf 24.
2 and below the lower surface 44 of the rotor end ring 22 . By arranging the holes 40 in the pickup tube 28 in this way, the holes 40
There is no obstruction to the oil spray 46 from 0 and the oil spray 46 is directed directly towards the radially inner surface of the stator end turn 24.

An enclosure 48 is fixed to the bottom of the outer housing 4 and surrounds the pick amplifier tube 28 to reduce the effects of cavitation.
It is fixed coaxially with and spaced apart from. enclosure 4
8 is provided with a plurality of holes 50 through which oil from the oil sump 12 can enter the enclosure 48.

Regarding operation, the crankshaft is rotated when motor compressor unit 2 starts, and enclosure 48
Rotate the pickup tube 28 inside. The oil in the oil sump 12 is then drawn upwardly through the shaft hole 36, and some of the oil is used to further lubricate the compressor components in the upper part of the motor-compressor unit 2 in the passages 16, 18 . 20 and sent upward.

The remaining oil siphoned upwardly through the shaft hole 36 is blown radially outwardly through the hole 40 and directly toward the radially inner surface 42 of the stator end turn 24 . Moreover, because the holes 40 are located below the lower surface 44 of the ring 22, the oil spray 46 does not contact any parts of the motor-compressor unit before contacting the inner surface 42 of the stator end turn 24. . This substantially eliminates the possibility of an increase in temperature of the oil spray 46 that would reduce the cooling effect of the stator end turf 24 by the cooling system 14.

Although the tree has been described as having one limited embodiment, it will be appreciated that further variations are possible. This application is therefore intended to cover any other variations, uses, or adaptations consistent with the general principles of the invention and which are within the scope of those known or practiced in the art to which the invention pertains. It is intended to include any modifications of this disclosure that come within the scope of the appended claims.

[Effects of the Invention] As explained in detail above, in the cooling device according to the present invention, the oil that is blown radially outward onto the lubricating oil big abutment tube comes into contact with other motor parts during its flight. The holes are placed at axial positions such that they fly directly toward the radial inner surface of the stator lower end turn. The oil that is blown radially outward through this hole is drawn directly from the sump by the lubricant pick-up tube, so that the oil in that area maintains a substantially constant temperature, with a maximum can provide cooling. Also, because the wicked oil does not come into contact with any other motor components before contacting the stator lower end turn, the stator cooling achieved by this oil is different from the conventional cooling systems described above. This is more effective than the resulting cooling.

Furthermore, compared to the conventional cooling devices mentioned above, the cooling device of the present invention has a significantly lower assembly cost. I mean,
This is because the cooling device of the present invention does not include additional structural elements, such as a flange extending radially from the top of the pickup tube, a group of recesses within the radial flange, or a plurality of coaxial pickup tubes. .

A further advantage of the cooling system according to the present invention is that by directing the oil to the end turns, the tight tolerance requirements of the lower stator end turns can be relaxed, as is the case with some prior art compressors. Submerging the end turns in oil is no longer the determining factor in motor temperature control.

[Brief explanation of the drawing]

The accompanying drawing is a longitudinal cross-sectional view of the lower portion of a hermetic motor compressor unit incorporating a preferred embodiment of the present invention.

Claims (4)

[Claims] (1) An outer housing having a lubricating oil sump at the bottom, a rotatable crankshaft vertically disposed within the housing, a stator circumferentially disposed around the rotary crankshaft, and the rotary crank. an airtight motor compressor unit comprising a motor having a rotor connected to a shaft and rotating; a centrifugal oil pick-up tube having an axial bore extending perpendicularly to said other end and extending upwardly from said other end, said stator having a lower end turn extending downwardly within said outer housing; an end turn has a radially inner surface in radially proximate and spatially spaced relationship with the pick-up tube, the pick-up tube being in communication with the shaft hole therein and having a radial inner surface in radially proximate and spatially spaced relationship with the pick-up tube; radial passage means in direct facing relationship with the lower end turn for directing a portion of the lubricating oil drawn up through the shaft bore radially outwardly through the radial passage means and An end-turn cooling device for a motor in a compressor, characterized in that it blows directly towards the radially inner surface of said lower end-turn before contacting other parts. (2) The lower end turn of the stator is characterized in that its bottom portion is immersed in the lubricating oil reservoir. Cooling system. (3) An end-turn cooling device for a motor in a compressor according to claim 1, wherein the diameter of the radial passage means is smaller than the diameter of the shaft hole. (4) The motor in the compressor according to claim 1, wherein the radial passage means is formed by one hole in the pickup pipe and is located at a position lower than the second rotor in the axial direction. end turn cooling system.