JPH03179189A - Oil feeder for scroll fluid machinery - Google Patents

Abstract

PURPOSE:To increase an amount of oiling to a sliding bearing by installing a spiral groove in the inner circumference of the sliding bearing for a scrol driving shaft and an oil filler port incongruent with this groove in this driving shaft, respectively, and thereby performing the oiling with a pressure differential between discharge pressure and intermediate pressure. CONSTITUTION:An upper compressor part 2 with both scrolls 5, 6 and a lower motor part 3 are connected together a crankshaft 9 in which a main bearing 10 and an oil feeding passage 13 leading lubricating oil to a pivot receiver 12 is installed. An oil feeding passage 20 being interconnected to the oil feeding passage 13 is installed in the crankshaft 9 sliding with a lower bearing 11, and a spiral oil groove 19 is installed in this lower bearing 11 upward in a position where it will not interfere with this oil feeding passage 20. Since discharge pressure oil is fed to the sliding bearing 11 from the oil feeding passage 20 and it is interconnected to an intermediate pressure chamber 15 by way of the oil groove 19, oiling takes place with a pressure differential between discharge pressure and intermediate pressure, thus a sufficient oiling quantity is secured, thereby preventing seizure or binding from occurring.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a lubricating device for a scroll fluid machine used in a compressor, an expander, a liquid pump, or the like.

[Conventional technology]

The principle of compression in scroll fluid machines, the force acting on the drive shaft in this type of scroll fluid machine, the lubricating method, the bearing structure, etc. are described in Japanese Patent Publications No. 19803-1980 and No. 16561-1983. . Conventionally, the method for lubricating the bearings provided at the lower end of the frame of this type of scroll fluid machine has been to use centrifugal force generated by rotation of the drive shaft. In addition, a sliding bearing installed in the frame with one end at discharge pressure and the other end at intermediate pressure has a lubricating method in which an oil groove is provided on the outer circumferential surface of the drive shaft parallel to the axis, and one end is provided with an oil hole in the shaft. The other end of the oil groove was set to have an intermediate pressure, and oil was supplied by the differential pressure between the discharge pressure and the intermediate pressure. In addition,
The oil supply groove was provided at a position away from the line of action of the load, and the oil supply amount was adjusted by the resistance of the oil supply groove.

[Problem to be solved by the invention]

In the above conventional technology, oil is supplied to the sliding bearing provided at the lower end of the frame using pressure caused by the centrifugal force of the oil in the oil supply hole due to rotation of the drive shaft, so the pressure is small and it is difficult to secure the amount of oil supplied. Met.

This is especially difficult when the rotation speed of the drive shaft is low.
Bearing galling could occur, leading to wear and seizure.

In addition, in a method in which a lubrication groove is provided on the outer peripheral surface of the drive shaft parallel to the axis, and the resistance of this lubrication groove is used to supply lubrication with the differential pressure between the discharge pressure and the intermediate pressure, the pressure difference is large, so the depth of the groove causes resistance. It was difficult to stabilize the amount of oil supplied.

In this way, when an oil supply groove is provided on the drive shaft, it is necessary to increase the resistance, so the groove needs to be very small, and it is difficult to collect oil in the groove. One side of the is at the discharge pressure, and the end face is at the intermediate pressure, and as the pressure is reduced from the discharge pressure to the intermediate pressure within the groove, the refrigerant contained in the hydraulic pressure boils within the groove and runs out of oil, causing galling of the shaft and causing wear and tear. Burn-in may occur.

An object of the present invention is to provide an inexpensive and reliable oil supply device that prevents wear and seizure of the sliding bearings provided in the frame, especially the sliding bearings provided in the drive source of the frame.

[Means to solve the problem]

In order to achieve the above objective, the method of lubricating the sliding bearing on the drive source side installed in the frame has changed from lubricating using centrifugal force due to rotation of the drive shaft to lubricating using the differential pressure between discharge pressure and intermediate pressure. The oil supply amount is increased by increasing the pressure, a spiral groove is provided on the inner circumferential surface of the sliding bearing, an oil supply hole that does not match this groove is provided on the drive shaft, and the oil at the discharge pressure is guided to the oil supply hole. Oil is supplied to the spiral groove from this oil supply hole.

[Effect]

One end of the slide bearing of the frame communicates with the intermediate pressure chamber via a roller bearing, and the pressure in this portion is approximately intermediate pressure. Further, the other end of the slide bearing is at discharge pressure. One end of the slide bearing communicates with the intermediate pressure chamber, and the other end is provided with a spiral groove spaced apart from the discharge pressure end side of the slide bearing. The drive shaft is provided with an oil hole for supplying oil to this spaced portion, and this oil hole is supplied with oil at a discharge pressure. Therefore, one end of the slide bearing is supplied with oil at a discharge pressure, so the oil flows into the spiral groove through the sliding portion, and the inside of the groove is filled with oil at an intermediate pressure. By lubricating the sliding bearing of the frame with the differential pressure between the discharge pressure and the intermediate pressure, the amount of lubricant can be increased compared to centrifugal force lubricating, and at the same time, the sliding part of the bearing is provided with a spiral groove. This enables reliable refueling.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1, 2, and 3. FIG. 1 shows a sectional view of the entire structure of a hermetic scroll compressor embodying the present invention.

In FIG. 1, a compressor section 2 is disposed in the upper part of the closed container 1, and an electric motor 3 is provided in the lower part thereof, and an oil reservoir 4 for lubricating oil is formed at the bottom of the closed container 1. The compressor section 2 is integrated with a fixed scroll 5 having a spiral wrap 5a on the base plate, an orbiting scroll 6 having a spiral wrap 6a on the base plate, and the fixed scroll 5. a frame 7 supporting a scroll 6;
It has a structure in which the laps of the fixed scroll 5 and the orbiting scroll 6 are engaged with each other.

Furthermore, an Oldham mechanism 8 is provided between the orbiting scroll 6 and the frame 7 to prevent the orbiting scroll 6 from rotating. The electric motor 3 is press-fitted into the closed container 1 and rotates the orbiting scroll 6 via the crankshaft 9. The crankshaft 9 is supported by a main bearing 10 and a lower bearing 11 provided on the frame 7, and its crank pin is fitted into an orbiting bearing 12 provided on the back surface of the orbiting scroll 6.

Inside the crankshaft 9 is a main bearing 10. An oil supply passage 13 is provided to guide lubricating oil to the lower bearing 11 and the swing bearing 12, and an oil supply device 114 is provided at the shaft end of the electric motor 3 to suck up lubricant oil from the oil reservoir 4 and send it to the oil supply passage 13. .

In the compressor section 2, when the orbiting scroll 6 is rotated via a crankshaft 9 driven by an electric motor 3, a space (compression chamber) formed by the orbiting scroll 6 and the fixed scroll 5 moves toward the center of the scroll. As the refrigerant gas is sucked in, the volume decreases and the refrigerant gas is compressed. The compressed refrigerant gas is discharged from a discharge port 16 provided at the center of the base plate of the fixed scroll to an upper space 17 within the closed container.

Furthermore, an intermediate pressure chamber 15 is formed on the back side of the rotating scroll gear to which gas for the compression stroke is introduced.

The pressure in the intermediate pressure chamber 15 is between the suction pressure and the discharge pressure of the refrigerant gas, and oil supply to the sliding portion of the scroll is performed using the differential pressure between the discharge pressure and the intermediate chamber pressure. FIG. 2 is an enlarged view for explaining the lower bearing 11. FIG. The main bearing 10 is a roller bearing consisting of an outer ring 10a, an inner shaft 10b, rollers 10c, etc., and a thrust bearing 18 is provided at the lower end of the inner ring 10b to support the crankshaft 9. A groove is provided on the surface of the thrust bearing 18. In this way, the upper end surface of the lower bearing 11 is at the pressure of the intermediate pressure chamber 15, and the pressure at the lower end is at the discharge pressure.

Further, an oil supply hole 20 is provided in the crankshaft 9 that slides on the lower bearing 11 so that the sliding portion and the oil supply passage 13 are communicated with each other. At the same time, the lower bearing 11 has this oil supply passage 20.
A spiral oil groove 19 is provided that communicates with the upper end of the lower bearing 11 from a position where it does not interfere with the upper end of the lower bearing 11 in a direction in which oil in the groove is discharged to the upper end by rotation of the crankshaft 9. Lubricating oil is supplied to the lower bearing 1 from the oil supply device 14 through the oil supply passage 13 on one side.
1 through the oil groove 19 to the intermediate pressure chamber 15,
The other oil flows into the intermediate pressure chamber 15 after lubricating the swing bearing 12 . The lubricating oil that has flowed into the intermediate pressure chamber 15 flows into the compression chamber through the intermediate hole 6b, and flows into the upper space 17 in the closed container 1 through the discharge port 16 provided at the center of the fixed scroll 5 in a state where it is mixed with refrigerant gas. Exhale. In this way, the intermediate pressure chamber 15
The oil that has oiled the swing bearing 12 and the lower bearing 11 flows into.

The above example shows an embodiment in which a single spiral oil groove 19 is provided in the lower bearing 11, but as shown in FIG. 5, a plurality of spiral oil grooves 19 are provided and It is also possible to increase the amount of oil supplied. Figure 6 is.

A developed view of the bearing shown in FIG. 5 is shown, where the oil groove 21
a, 21b are added to the oil groove 19 shown in FIGS. 3 and 4, and the distances ax and Qz are approximately equal, and 21a,
21b is a distance Q so that there are - oil grooves when made into a cylindrical shape.
se Qa are equal.

FIGS. 7 and 8 show embodiments with different oil groove shapes. 7th
The figure shows an example in which part of the width of the oil groove is narrowed in order to reduce the amount of oil supplied from the oil supply passage 20 to the lower bearing 11.

FIG. 8 shows an example in which a circumferential oil groove and a spiral oil groove are provided in communication with each other in order to increase the amount of oil supplied from the oil supply passage 20 to the lower bearing 11.

〔Effect of the invention〕

According to the present invention, it is possible to supply oil to the lower bearing using the differential pressure between the discharge pressure and the intermediate pressure without providing an axial oil groove in the crankshaft, and at the same time, it is possible to collect oil in the sliding part. - There is no seizure even if there is a temporary lack of lubrication, and the groove depth can be made larger than when an oil groove is provided on the crankshaft, increasing the oil storage capacity and ensuring sufficient lubrication. It is possible to secure the quantity and prevent seizure of the bearing. Additionally, it is possible to supply oil without providing an oil groove on the crankshaft, improving processing efficiency during manufacturing.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view of a hermetic scroll compressor according to an embodiment of the present invention, Fig. 2 is an enlarged sectional view of the bearing portion of Fig. 1, Fig. 3 is a sectional view of the lower bearing portion, and Fig. 4 is the developed view of Figure 3,
FIG. 5 is a partial sectional view of another embodiment, FIG. 6 is a developed view of FIG. 5, and FIGS. 7 and 8 are developed views of a lower bearing of another embodiment. DESCRIPTION OF SYMBOLS 1... Sealed container, 2... Compression equipment, 5... Fixed scroll, 6... Orbiting scroll, 7... Frame, 9... Rirank shaft, 10... Main bearing, 1 ...lower bearing, 2 ...swivel bearing. 13...Oil supply passage, 15...Intermediate pressure chamber, rod figure 9/-7 kun 7 medium 1 IP axis Q lta medium raFL chamber quick leap No. 40 9 mower mouth 19... Meb pestle Child diagram number (2) Kaya δ diagram

Claims (1)

[Claims] 1. The structure is such that the pressure in the space formed by the back surface of the orbiting scroll and the frame is set to an intermediate pressure greater than the suction pressure and lower than the discharge pressure, and the orbiting scroll is brought into close contact with the fixed scroll, and the orbiting scroll is driven. In a scroll fluid machine in which the shaft is supported by a rolling bearing and a slide bearing provided in the frame, one end surface of the slide bearing is at the discharge pressure, the other end is at the intermediate pressure, and the slide bearing is located near the discharge pressure side in the slide bearing. The opposing drive shafts are provided with a radial oil supply hole from the oil hole in the shaft, and the inner peripheral surface of the slide bearing has one end communicating with the intermediate pressure and the other end interfering with the oil supply hole. 1. An oil supply device for a scroll fluid machine, characterized in that a single or plural spiral oil grooves are provided, and oil is supplied using a differential pressure between the discharge pressure and the intermediate pressure.