JPH07224774A - Scroll compressor - Google Patents

Abstract

PURPOSE:To provide a lubricant supply mechanism excellent in operation efficiency by adjusting the hydraulic pressure and gas pressure applied to the high- pressure chamber and the low-pressure chamber at the rear of a rotary scroll corresponding to the thrust force of a compression chamber, in any operation state of a scroll compressor. CONSTITUTION:A slot 7a is made from the inner bottom to the periphery of a crank shaft 5 made at the upper part of a shaft 11, and an oil slit 7b, which inclines opposite to the direction of rotation, is made from the oil slit 7a to the top of the periphery of the crank shaft 7. A through hole, which becomes expensive if made in a frame 9, is omitted, and in the crank shaft 7, a return groove 7c, which inclines in the rotational direction to the discharge port 7 at the bottom of the periphery of the crank shaft 7, is made, at the opposite side of the oil slit 7d, from the top of the periphery. The bore of the discharge port 7d is adjusted not to let the quantity of lubricant in the high-pressure chamber 19 decrease too much.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and more particularly to an oil supply structure for supplying lubricating oil to a high pressure chamber and a low pressure chamber partitioned by a tip seal on the rear surface of an orbiting scroll with reliable and stable hydraulic pressure. It is a thing.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional scroll compressor.
It will be described based on. As shown in FIG. 3, the scroll compressor includes a compression unit 2 and an electric motor 3 in a sealed container 1. The compression unit 2 is mainly composed of a fixed scroll 4, an orbiting scroll 5, an Oldham ring 6, a crank shaft 7, an eccentric bearing 8, a frame 9, a crank bearing 10, and a shaft 11. In this structure, the end plate 4a of the fixed scroll 4 is integrally formed with the wrap 4b in a spiral shape, and the fixed scroll 4 fixed to the frame 9 and the end plate 5a of the orbiting scroll 5 are swirled wrap 5b and swirled to the back. A plurality of compression chambers 12 are formed by engaging the orbiting scroll 5 integrally formed with the drive shaft 5c. Electric motor 3
When is rotated, the orbiting scroll 5 is rotated by the orbiting drive shaft 5c through the eccentric bearing 8 fitted to the crankshaft 7 formed on the shaft 11, and the Oldham ring 6 prevents the orbiting scroll 5 from rotating. The low-pressure refrigerant sucked from the suction pipe 13 into the compression section 2 by the orbiting motion of the orbiting scroll 5 is compressed while becoming a high-pressure refrigerant while sequentially moving from the outer peripheral portion of the compression chamber 12 to the central portion. This high-pressure refrigerant is supplied into the compression chamber 12 and is discharged from the discharge port 14 together with the lubricating oil that becomes mist while lubricating each sliding portion, passes through the communication passage 15, and is discharged from the lower portion of the frame 9 and the upper portion of the electric motor 3. The oil is guided to the motor chamber 16 formed of a space, and a mist-like lubricating oil is attached in the middle of the path to reduce the oil content, and the oil is discharged from the discharge pipe 17. The circulation route of the lubricating oil will be described. The lubricating oil accumulated in the lubricating oil reservoir 18 at the bottom of the sealed container 1 is pressed on the oil surface by the high pressure refrigerant,
Lubricating oil passage 1 that penetrates from the lower end to the upper end of the shaft 11
It is pushed up by the slinger provided on 1a and guided to the upper surface of the crankshaft 7. The lubricating oil pushed up to the upper surface of the crankshaft 7 lubricates the respective sliding parts through the passage groove 5d formed in the turning drive shaft 5c, the groove hole 7a formed in the outer periphery of the crankshaft 7 and the oil supply groove 7b. Meanwhile, the back surface of the end plate 5a of the orbiting scroll 5 is pushed in response to the thrust force applied to the high pressure center of the compression chamber 12 by being guided to the high pressure chamber 19. A tip seal 20 is provided at the contact portion between the rear surface of the end plate 5a of the orbiting scroll 5 and the upper surface of the frame 9 to divide the high pressure chamber 19 and the low pressure chamber 21 into a high pressure chamber 19 filled with lubricating oil and a high pressure chamber 21. Prevents leakage of refrigerant. A part of the lubricating oil leaked from the tip seal 20 to the low pressure chamber 21 is supplied to the Oldham ring 6 and the compression chamber 12. If the hydraulic pressure in the high pressure chamber 19 becomes too high, the high pressure chamber 19
A through hole 9a extending from the upper surface of the inner frame 9 to the lower surface of the motor chamber 16 is bored to discharge excess lubricating oil. However, the through hole 9a formed in the frame 9 and having a small hole diameter requires a difficult drilling process, resulting in high cost. Further, in an operating state such as a capacity control operation that has been recently demanded, the rotation speed of the electric motor 3 changes significantly. For this reason, the pressure of the high pressure chamber 19 becomes high at the time of high speed rotation when the through hole 9a has a small diameter based on the time of low speed rotation.
The amount of oil leaking to 1 increases, the pressure in the low pressure chamber 21 also increases, and the thrust force that pushes the back surface of the end plate 5a increases. With a large hole diameter of the through hole 9a based on the high speed rotation, the high pressure refrigerant does not fill the high pressure chamber 19 with the lubricating oil at the low speed rotation, and therefore the high pressure refrigerant is insufficient in the lubricating oil from the high pressure chamber 19. Leaking into the low pressure chamber 21 through the high pressure chamber 1
9 and the low-pressure chamber 21 both increase the thrust force that pushes the rear surface of the end plate 5a, which deteriorates the operating efficiency.

[0003]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a high pressure chamber on the back surface of an orbiting scroll corresponding to the thrust force of the compression chamber in any operating condition of the scroll compressor. The purpose of the present invention is to provide a lubricating oil supply structure that adjusts the hydraulic pressure and gas pressure applied to the low-pressure chamber and does not reduce the operating efficiency at a low cost.

[0004]

According to the present invention, a compression section and an electric motor are arranged in a hermetic container, and the compression section is engaged with a spiral scroll and a fixed scroll to form a compression chamber. Revolving scroll, an Oldham ring that prevents rotation of the revolving scroll, a shaft that revolvingly drives the revolving scroll and forms a lubricating oil feed passage that penetrates from the lower end to the upper end, and the outer periphery formed on the upper end of the shaft. And a frame for supporting a crankshaft having a lubricating oil supply groove, and a return groove is provided on a surface of the crankshaft opposite to the oil supply groove. Further, the return groove is formed to have an inclination opposite to the oil supply groove, the inclination is increased in a counter-rotational direction of the shaft, and the inclination of the return groove is increased in a rotational direction. .

[0005]

According to the present invention, the lubricating oil guided to the crankshaft formed on the upper part of the shaft for orbiting the orbiting scroll passes through the groove hole and the oil supply groove formed on the outer periphery which slides with the crank bearing of the frame. Guided to the high pressure chamber. A through passage is formed in the frame with a hole diameter based on the low speed rotation of the shaft. When the shaft rotates at high speed due to the operating state of the scroll compressor, the amount of lubricating oil introduced from the lubricating oil reservoir to the high pressure chamber through the lubricating oil passage, the upper part of the crankshaft and the oil supply groove increases, and the oil pressure increases. When it becomes higher, it is sent from the return groove to the discharge hole at the lower part of the crankshaft and discharged to the motor chamber. It is possible to cope with the thrust force of the compression chamber by the hydraulic pressure of the high pressure chamber without leaking a large amount of lubricating oil to the low pressure chamber. On the other hand, when the shaft rotates at low speed, the amount of lubricating oil supplied decreases, and when the oil pressure decreases, high-pressure refrigerant enters the high-pressure chamber through the discharge hole, and the low-speed rotation also reduces discharge of lubricating oil from the discharge hole. It is possible to prevent the high pressure refrigerant from leaking to the low pressure chamber by holding the lubricating oil in the tip seal, and to respond to the thrust force of the compression chamber by the pressure of the high pressure refrigerant in the high pressure chamber.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. This embodiment is shown in FIG. 3 except for the down groove formed on the crankshaft 7 above the shaft 11 and the components related to the discharge hole.
Since it is the same as the conventional example shown in FIG. Note that the same numbers are used for the same component numbers. As shown in FIGS. 1 and 2, a groove hole 7a is formed from the inner bottom portion of the crankshaft 7 formed on the upper portion of the shaft 11 to the outer periphery, and the groove 11a extends from the groove hole 7a to the outer peripheral upper end portion of the crankshaft 7. An oil supply groove 7b that is inclined in the direction opposite to the rotation direction is formed. A return groove 7c is formed on the opposite surface of the oil supply groove 7b of the crankshaft 7 from the upper end of the outer periphery to the discharge hole 7d formed at the lower end of the outer periphery of the crankshaft 7 inclining in the rotational direction. The amount of lubricating oil discharged from the high-pressure chamber 19 is adjusted so as not to decrease excessively with the diameter of the discharge hole 7d. The lubricating oil pushed up to the inner bottom of the crankshaft 7 is, on the other hand, the passage hole 5d formed by the turning drive shaft 5c.
On the other hand, through the groove hole 7a and the oil supply groove 7b on the other hand, the respective sliding portions are lubricated and both are guided to the high pressure chamber 19. The lubricating oil is discharged from the return groove 7c through the discharge hole 7d to the motor chamber 16 when the required pressure is exceeded due to the hydraulic pressure in the high pressure chamber 19 which changes according to the operating state, that is, the rotation speed of the shaft 11. The inclinations provided in the oil supply groove 7b and the return groove 7c form inclinations that work in the pushing direction in the oil supply groove 7b and in the pushing down direction in the return groove 7c, respectively, with respect to the rotation direction of the crankshaft.

[0007]

Therefore, according to the present invention, even if the capacity of the scroll compressor is controlled to drastically change the rotation speed of the electric motor, the passage groove formed in the orbiting drive shaft and the oil supply groove formed in the crankshaft are used. Lubricating oil is supplied, the through hole formed in the frame is omitted, and the return groove formed in the crankshaft discharges the lubricating oil that exceeds the required pressure to adjust the pressure in the high pressure chamber behind the end plate of the orbiting scroll. Therefore, it is possible to perform efficient operation at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a main part of a scroll compressor according to an embodiment of the present invention.

FIG. 2 is a plan view and a side view showing a main part of a crankshaft according to an embodiment of the present invention.

FIG. 3 is a cross-sectional view showing an outline of a conventional scroll compressor.

[Explanation of symbols]

 1 sealed container 2 compression part 3 electric motor 4 fixed scroll 5 orbiting scroll 5a orbiting scroll end plate 5c orbiting drive shaft 5d passage groove 6 Oldham ring 7 crankshaft 7a groove hole 7b oil supply groove 7c return groove 7d discharge hole 9 frame 9a through hole 11 Shaft 11a Lubricating oil passage 12 Compression chamber 15 Communication passage 16 Motor chamber 18 Lubricating oil reservoir 19 High pressure chamber 20 Tip seal 21 Low pressure chamber

Claims (3)

[Claims] 1. A compression unit and an electric motor are arranged in a sealed container,
The compression unit, a spiral scroll, a orbiting scroll that meshes with the fixed scroll to form a compression chamber, an Oldham ring that prevents rotation of the orbiting scroll, and orbitally drives the orbiting scroll, A shaft formed with a lubricating oil passage that penetrates from the lower end to the upper end,
A scroll compression characterized by comprising a frame for supporting a crankshaft having a lubricating oil supply groove formed on the upper end of the shaft and having a lubricating oil supply groove on the outer periphery thereof, and providing a return groove on the surface of the crankshaft opposite to the oil supply groove. Machine. 2. The scroll compressor according to claim 1, wherein the return groove is formed with an inclination opposite to the oil supply groove. 3. The scroll compression system according to claim 1, wherein the inclination of the oil supply groove is increased in the counter-rotational direction of the shaft, and the inclination of the return groove is increased in the rotational direction. Machine.