JPH0584395B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a scroll compressor used in a refrigeration cycle or the like, and particularly to a thrust support system for a scroll that performs an orbiting motion.

BACKGROUND ART In recent years, scroll compressors have become mainstream, especially in the packaging industry, due to their high efficiency and low vibration. Figure 2 shows the configuration of a conventional scroll compressor.
This will be explained with reference to FIG.

Reference numeral 1 designates a sealed casing, 2 a motor section, and a mechanical section main body 7 comprising a block 3, a fixed scroll 4, an orbiting scroll 5, and an anti-rotation mechanism 6 is fixed to the upper part of the motor section. fixed scroll 4
consists of an end plate 4a and a lap 4b formed of an involute or a curve similar to an involute standing upright on the end plate 4a and having a uniform thickness and height, and is fixed to the block 3 by the end plate 4a. The orbiting scroll 5 is composed of an end plate 5a and a lap 5b that stands upright on the end plate 5a and has the same curve as the wrap 4b of the fixed scroll 4. The end plate 5a allows a slight clearance between the end plate 4a of the fixed scroll 4 and the block 3. It is provided and supported by being sandwiched, and is restrained by an anti-rotation mechanism 6. The fixed scroll 4 and the orbiting scroll 5 have winding end ends 4b' and 5 of each wrap 4b and 5b.
They are put together with b′ shifted by a certain angle.

8 is a discharge hole, and 9 is a suction hole. The discharge hole 8 communicates with the center of the involute of the fixed scroll 4, and the suction hole 9 communicates with the suction chamber 9a at the outer edge of the end plate 4a of the involute of the fixed scroll 4. There is.
10 is a protrusion provided on the surface of the orbiting scroll 5 opposite to the wrap 5b;
It is concentric with the center of the involute of b. Reference numeral 11 denotes a shaft supported by a thrust bearing 12, and the protrusion 10 of the orbiting scroll 5 is housed in a boss portion 11a provided at the ends of the seven machine body parts, eccentric from the shaft center, so that the shaft rotates with the electric motor section 2. The scrolls 5 are connected. In addition, an oil supply hole 11b penetrates through the center of the shaft 11,
Boss portion 11a of shaft 11 and orbiting scroll 5
An oil supply path L is formed that communicates the oil reservoir space 13 formed by the projection 10 with the lower part of the sealed casing 1.

Reference numeral 14 denotes a back pressure chamber formed on the back surface of the orbiting scroll 5, which is sealed from the lap 5b side of the orbiting scroll 5 by end plates 5a, 4a, and is connected to the compression space S formed by the fixed scroll 4 and the orbiting scroll 5. Communication hole 14 provided in scroll 5
They communicate via a and 14b. 15 is a suction pipe communicating with the suction hole 9, 16 is a discharge pipe, and 17
is the lubricating oil collected at the bottom of the sealed casing.

Next, the compression mechanism of the scroll compressor will be explained. The rotational movement of the shaft 11 accompanying the rotation of the electric motor section 2 is transmitted to the orbiting scroll 5 via the boss section 11a and the protrusion section 10, but due to the action of the rotation prevention mechanism 6, the orbiting scroll 5 does not rotate on its own axis and becomes a fixed scroll. It rotates around the center of the involute No. 4 as the rotation center. At this time, the winding end 5b' of the wrap 5b of the orbiting scroll 5 is connected to the wrap 4b of the fixed scroll 4.
Suction is complete when the winding ends 4b' of the wraps 4b are in contact with the wraps 5b of the orbiting scroll 5, and as the orbiting scroll 5 revolves, the two contact points between the wraps 4b and 5b are involute. The pressure in the compression space S increases as it approaches the center.

By the compression mechanism of this scroll compressor, the refrigerant sucked from the suction pipe 15 through the suction hole 9 is compressed and once passed through the discharge hole 8 into the sealed casing 1.
After being discharged into the interior, the liquid is discharged through a discharge pipe 16 to a cooling system (not shown). At this time, as the pressure in the compression space S increases, a thrust force is generated between the fixed scroll 4 and the orbiting scroll 5 that tends to separate them in the axial direction. If the fixed and orbiting scrolls 4 and 5 are separated by this thrust force, the seals on the axial end faces of the wraps 4b and 5b in contact with the end plates 4a and 5a will be incomplete, increasing leakage and reducing efficiency. Therefore, conventionally, an intermediate pressure that has not reached the discharge pressure during the compression stroke is introduced into the back pressure chamber 14 on the back surface of the orbiting scroll 5 through communication holes 14a and 14b, and the thrust force caused by the compressed gas is applied to the orbiting scroll 5. In addition to applying the above appropriate pressing force, the lubricating oil 17 is applied to the oil supply hole 1 of the shaft 11.
1b, flows into the back pressure chamber due to the pressure difference between the high pressure in the sealed casing 1 and the intermediate pressure in the back pressure chamber 14, and partially flows into the compression chamber S through the communication holes 14a and 14b.
(For example, there is Japanese Patent Publication No. 57-49721).

Problems to be Solved by the Invention In such a conventional method, in order to obtain an intermediate pressure, the back pressure chamber 14 and the compression chamber S during the compression stroke are connected to the communication hole 14.
Since the communication holes 14a and 14b are opened and closed by the wrap 4b, the intermediate pressure may become unstable if the holes are not opened accurately, and the communication holes 14a and 14b may be opened and closed by the wrap 4b, or the intermediate pressure may become unstable. When machining from
Since the holes are opened near the lap 5b, the communication holes 14a and 14b overlap the lap 5b, making it impossible to obtain a sufficient opening area. Also, the compression chamber S and back pressure chamber 1 during the compression stroke
4, the power loss and volumetric efficiency decrease due to leakage of gas that has been pressurized to an intermediate pressure, and conversely,
Problems such as an increase in power due to the inflow of gas into the compression chamber, and the small diameter of the communication holes 14a and 14b make it difficult for the lubricating oil in the back pressure chamber to be supplied to the compression chamber S, resulting in insufficient oil sealing. There was a problem.

The present invention eliminates the drawbacks of the above-mentioned conventional examples, and aims to generate an appropriate thrust holding force in the same manner as the conventional examples, and to improve efficiency by facilitating machining and reducing power loss.

Means for Solving the Problems The present invention comprises a sealed casing, a fixed and orbiting scroll in which mutually interlocking laps are made upright from a head plate, and a guide provided in the radial direction of the orbiting scroll on the side opposite to the laps of the head plate of the orbiting scroll. groove and
an anti-rotation mechanism that is slidably held in a guide groove in the radial direction of the orbiting scroll and prevents the orbiting scroll from rotating and allows the orbiting scroll to perform an orbiting motion; a suction chamber formed on the outer periphery of the fixed scroll and the orbiting scroll; A back pressure chamber is formed on the opposite wrap side of the end plate of the scroll, and a suction chamber is formed at a position opened and closed by the sliding movement of the orbiting scroll in the radial direction of the rotation prevention mechanism due to the orbiting movement of the orbiting scroll in the guide groove. It includes a communication hole that communicates with the back pressure chamber, and an oil supply path that connects the back pressure chamber and the lower part of the sealed casing where lubricating oil accumulates.

Effect The present invention has the above-described configuration, so that when lubricating oil flows into the back pressure chamber from the lower part of the sealed casing and the back pressure chamber is about to be pressurized to a high pressure by the gas contained in the lubricating oil, the back pressure is connected to the suction chamber. The pressure in the back pressure chamber is maintained at an appropriate intermediate pressure by communicating the chambers through a communication hole and opening and closing the communication hole using an anti-rotation mechanism, and the communication range of the communication hole can be adjusted freely depending on the opening position. Since it is adjustable, the diameter of the communicating hole can be made larger, and there is no need to provide a connecting hole near the lap as in the past, making processing easier.Furthermore, the larger diameter of the communicating hole makes it easier to supply lubricating oil to the back pressure chamber. The wrap part can be refueled, improving volumetric efficiency, and there is no increase in power due to gas flowing into the compression chamber.

Embodiment An embodiment of the present invention will be described below with reference to FIG. It should be noted that the same parts as in the conventional example are given the same reference numerals and explanations will be omitted.

The scroll type compressor of this embodiment includes a hermetic casing 1, fixed and orbiting scrolls 4, 18 with mutually engaged laps 4b, 18b standing upright from end plates 4a, 18a, and an end plate 18a of the orbiting scroll 18 on the side opposite to the laps. Guide grooves 19a, 19b provided in the radial direction of the orbiting scroll 18, and the orbiting scroll 1 held slidably in the radial direction of the orbiting scroll 18 within the guide grooves 19a, 19b.
an anti-rotation mechanism 6 that prevents the rotation of the scroll 8 and allows it to rotate; a fixed scroll 4 and an orbiting scroll 1;
8, a back pressure chamber 14 formed on the opposite side of the end plate 18a of the orbiting scroll 18, and a rotation prevention mechanism 6 due to the orbiting movement of the orbiting scroll 18 in the guide grooves 19a, 19b. Holes are opened at positions that are opened and closed by the sliding movement of the orbiting scroll 18 in the radial direction, and a suction chamber 9a and a back pressure chamber 14 are opened.
Communication holes 20a, 20b that communicate with the back pressure chamber 14
and an oil supply path L connecting the lower part of the sealed casing 1 where the lubricating oil 17 accumulates.

In the above configuration, when the operation is performed, the pressure in the suction chamber 9a decreases due to the compression action, and the pressure inside the sealed casing 1 becomes high. At this time, the back pressure chamber 14 communicates with the suction chamber 9a through the communication holes 20a and 20b, and as the pressure in the suction chamber 9a decreases, either the communication hole 20a or the communication hole 20b is opened at a position where the communication hole 20b communicates with the suction chamber 9a. Therefore, the pressure in the back pressure chamber 14 also decreases. Furthermore, when the pressure in the back pressure chamber 14 decreases, the lubricating oil 17 is supplied to the oil supply hole 1 due to the differential pressure as in the past.
1b, the high-pressure gas contained in the lubricating oil 17 flowing into the back pressure chamber 14 via the oil reservoir space 13 is partially vaporized. As a result, it is necessary to adjust the pressure in the back pressure chamber 14 to a certain level or to maintain an appropriate thrust force against the thrust force of the compressed gas.
This is done depending on the hole diameters of holes a and 20b and the opening/closing time of communication holes 20a and 20b by rotation prevention mechanism 6. Therefore, by adjusting the opening/closing time, it is possible to increase the diameter of the communication holes 20a and 20b, and the diameter of the communication holes 20a and 20b can be increased.
Since there is no need to drill holes in areas where machining accuracy is required, such as near b, machining becomes easier, and the back pressure chamber 14
The lubricating oil 17 inside can be easily supplied to the compression chamber S through the suction chamber 9a, improving volumetric efficiency, and since no gas flows into the compression chamber during compression, power is also reduced.

Effects of the Invention As is clear from the above description, the present invention comprises a sealed casing, a fixed and orbiting scroll in which mutually interlocking laps are made upright from the end plate, and a fixed and orbiting scroll in which laps are provided in the radial direction of the orbiting scroll on the side opposite to the wraps of the end plate of the orbiting scroll. an anti-rotation mechanism that is held slidably in the guide groove in the radial direction of the orbiting scroll and prevents the orbiting scroll from rotating and allows the orbiting scroll to perform an orbiting motion; a suction chamber formed on the opposite lap side of the end plate of the orbiting scroll, and a rotation prevention mechanism formed by the orbiting movement of the orbiting scroll in the guide groove, which is opened and closed by the sliding movement of the orbiting scroll in the radial direction. Equipped with a communication hole that opens and communicates the suction chamber and back pressure chamber, and an oil supply path that connects the back pressure chamber and the lower part of the sealed casing where lubricating oil accumulates, so the communication range of the communication hole can be freely adjusted depending on the opening position. The diameter of the communication hole can be made larger because it can be adjusted to a larger diameter, and there is no need to provide a communication hole near the lap as in the conventional method, making processing easier. Furthermore, the larger diameter of the communication hole makes it easier to remove lubricating oil from the back pressure chamber. It is possible to supply oil to the lap part, which improves volumetric efficiency, and also eliminates the increase in power caused by the flow of gas into the compression chamber.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal cross-sectional view of a scroll compressor showing an embodiment of the present invention, Fig. 2 is a longitudinal cross-sectional view of a conventional scroll compressor, and Fig. 3 is a lap portion taken along the line -' in Fig. 2. It is an enlarged view of. DESCRIPTION OF SYMBOLS 1... Sealed casing, 4... Fixed scroll, 4a... End plate of fixed scroll, 4b... Wrap of fixed scroll, 6... Rotation prevention mechanism, 9
a... Suction chamber, 14... Back pressure chamber, 18... Orbiting scroll, 18a... End plate of orbiting scroll, 1
8b... Wrap of orbiting scroll, 19a, 19
b...Guide groove, 20a, 20b...Communication hole, L...
...Refueling route.

Claims (1)

[Claims] 1. A sealed casing 1, fixed and orbiting scrolls 4, 18 having laps 4b, 18b that engage with each other upright from the end plates 4a, 18a, and a radial direction of the orbiting scroll 18 on the side opposite to the laps of the end plate 18a of the orbiting scroll 18. provided guide grooves 19a, 19b; and an anti-rotation mechanism that is held in the guide grooves 19a, 19b so as to be slidable in the radial direction of the orbiting scroll 18, and prevents the rotation of the orbiting scroll 18 and allows the orbiting scroll 18 to perform an orbiting motion. 6 and
A suction chamber 9a formed on the outer periphery of the fixed scroll 4 and the orbiting scroll 18, a back pressure chamber 14 formed on the opposite lap side of the end plate 18a of the orbiting scroll 18, and the orbiting scroll in the guide grooves 19a and 19b. A communication hole 20 is opened at a position opened and closed by the radial sliding movement of the orbiting scroll 18 of the rotation prevention mechanism 6 due to the rotation movement of the rotation mechanism 18, and communicates the suction chamber 9a with the back pressure chamber 14.
a, 20b, and an oil supply path L that connects the back pressure chamber 14 and a portion in the lower part of the sealed casing 1 where lubricating oil 17 accumulates.