WO2015155798A1

WO2015155798A1 - Scroll compressor

Info

Publication number: WO2015155798A1
Application number: PCT/JP2014/001986
Authority: WO
Inventors: 哲仁 ▲高▼井; 角田　昌之; 石園　文彦
Original assignee: 三菱電機株式会社
Priority date: 2014-04-07
Filing date: 2014-04-07
Publication date: 2015-10-15

Abstract

There is demand for a scroll compressor that prevents an excessive amount of oil from being supplied during high-speed operation, enables a sufficient amount of oil to be supplied during low-speed operation, and does not cause fluctuations in the oil supply amount regardless of the presence of play. This scroll compressor (100) comprises: a main body vessel (1); a fixed scroll (9); an orbiting scroll (10); a rotary drive shaft (4) having an oil passage hole (4c); a frame (11); a ring-plate-shaped thrust plate (14) disposed between the orbiting scroll (10) and the frame (11); and an oil pump (22) for delivering a lubrication oil (Y). Some of the lubrication oil (Y) delivered into a recessed part (11b) of the frame (11) from the oil passage hole (4c) of the rotary drive shaft (4) flows to spiral teeth (10a) of the orbiting scroll (10) after passing between the orbiting scroll (10) and the thrust plate (14) and between the orbiting scroll and the frame (11). An oil passage groove (40) for connecting the inner peripheral surface (14b) of the thrust plate (14) to the outer peripheral surface (14c) is formed on the upper surface (14a) of the thrust plate (14).

Description

Scroll compressor

The present invention relates to a scroll compressor used in a refrigerant circuit such as an air conditioner or a refrigerator.

Conventionally, a general scroll compressor has a hermetic main body container, a fixed scroll fixed to a frame fixed in the main body container, and a swing that rotates around a rotation center that is eccentric with respect to the center of the fixed scroll. A scroll, a stator and a rotor constituting an electric mechanism section, a rotary drive shaft that is rotationally driven by the electric mechanism section, a slider that supports the orbiting scroll to revolve the orbiting scroll, and a slider rod that is a rotational drive shaft An eccentric shaft portion installed at the upper part of the rotary drive shaft so as to be eccentric with respect to the suction pipe, a suction pipe for introducing refrigerant gas from the outside, and a discharge pipe for discharging compressed refrigerant gas to the outside , A swing scroll, a thrust plate that is a thrust bearing, and a frame that supports a rotary drive shaft and is fixed to the fixed scroll with bolts, and a main body container A sub-frame that rotatably supports the rotary drive shaft at the bottom, and a positive displacement oil pump that sucks the lubricating oil accumulated at the bottom of the main body container up to the slider through the oil passage in the rotary drive shaft. ing.

In the conventional compressor having the above configuration, the lubricating oil sucked up to the slider is slid between the bearing metal of the orbiting scroll and the slider, or between the thrust surface of the orbiting scroll and the thrust plate. After having played the role which lubricates oil, it returns to the bottom part of a main body container from the inside of a frame through an oil drain pipe. Here, a part of the lubricating oil that lubricates the sliding portion between the thrust surface of the orbiting scroll and the thrust surface of the frame is caused to flow out of the thrust support surface and sucked into the spiral teeth at the upper position. Therefore, it is necessary to use for lubrication against sliding between the spiral teeth.

In order to introduce the lubricating oil into the spiral teeth in this way, the oil supply hole having a circular shape in plan view is provided in the thrust plate, and this oil supply hole is intermittently communicated with the counterbore (opening) for oil supply provided in the orbiting scroll. An intermittent oil supply mechanism is known. With this configuration, the lubricating oil on the back surface of the orbiting scroll is moved to the spiral tooth side of the orbiting scroll while communicating.

Japanese Patent Laid-Open No. 1-216116 (Example, FIGS. 1 to 5)

However, in the conventional intermittent lubrication mechanism of the scroll compressor, the hydraulic pressure by the pump discharge pressure is higher as the scroll compressor is operated at a high speed, so the amount of lubricating oil supplied to the back of the orbiting scroll is large, and the low speed rotation. On the other hand, there was a problem that the oil pressure due to the pump pressure was low and the amount of oil supply decreased. Therefore, when the scroll compressor is operating at high speed, there is a problem that the amount of lubricating oil supplied into the spiral teeth increases and the amount of lubricating oil taken out to the refrigerant circuit outside the scroll compressor increases. It was. Further, when the scroll compressor is operated at a low speed, the amount of lubricating oil supplied into the spiral teeth may be too small. In such a case, the spiral teeth formed of the cast iron material There was also a problem that spiral teeth were worn by sliding.

The conventional intermittent oil supply mechanism is a mechanism that adjusts the oil supply amount according to the time required for communication between the oil passage hole of the thrust plate and the counterbore for oil supply of the orbiting scroll, but there is a backlash between the thrust plate and the frame. In some cases, the communication time changes, and this causes a problem of varying the amount of oil supply.
On the other hand, there is known a thrust bearing composed of parallel disks that face each other and slide to supply oil by providing an oil passage groove on one of the sliding surfaces (the above-mentioned patent document). 1). However, the center of rotation of the sliding component is constant, and it is not a structure that swings while rotating eccentrically with respect to the counterpart.

The present invention was made to solve the above-described problems, and the amount of lubrication does not become too large when operating at high speed, and sufficient lubrication is possible even when operating at low speed. An object of the present invention is to obtain a scroll compressor that does not vary in the amount of oil supply even if there is play.

A scroll compressor according to the present invention comprises a main body container that is a sealed container, a fixed scroll that is fixedly disposed at the upper part of the main body container and has spiral teeth on the lower surface, and a compression chamber that meshes with the spiral teeth of the fixed scroll A swing scroll having a boss portion on the lower surface and an eccentric shaft portion rotatably engaged with a swing bearing of the boss portion of the swing scroll is formed on the upper end portion. A rotary drive shaft having an oil passage hole communicating vertically with the shaft; a thrust support surface that supports the orbiting scroll; a recess that is formed on the inner side in the container radial direction with respect to the thrust support surface and accommodates the boss portion of the orbiting scroll; And a frame formed at the lower portion of the recess and having a main bearing portion for pivotally supporting the rotary drive shaft and fixedly arranged on the inner peripheral surface of the main body container, and a lower surface and a frame of the orbiting scroll A ring plate-like thrust plate disposed between the thrust support surface and slidably supporting the lower surface of the orbiting scroll, and lubrication provided at the bottom of the main body container provided at the lower end of the rotary drive shaft An oil pump that pumps oil and sends it to the oil passage hole, and a part of the lubricating oil sent from the oil passage hole of the rotary drive shaft into the recess of the frame is the thrust support surface of the frame and the thrust plate And the sliding surface portion of the bottom surface of the orbiting scroll, and flows into the spiral teeth of the orbiting scroll. The oil passage that communicates the inner and outer peripheral surfaces of the thrust plate with the upper surface of the thrust plate. A groove is formed.

In the scroll compressor according to the present invention, the upper surface of the thrust plate is formed with an oil passage groove that communicates the inner peripheral surface and the outer peripheral surface of the thrust plate. When the rotational speed is low, the amount of oil supplied through the oil passage groove increases, and conversely, the amount of oil supplied is too large and the amount of oil circulating in the refrigerant is large. At the high rotation speed, which is likely to occur, the viscous pump action by the oil passage groove is increased, so that the amount of oil supplied to the spiral teeth is not excessively increased. In addition, since the oil passage groove is always in communication, the amount of oil supply does not vary even if there is play between the frame and the thrust plate.

It is a longitudinal cross-sectional view of the scroll compressor in Embodiment 1 of this invention. It is a plane sectional view of the thrust plate of the scroll compressor. It is a top view of the thrust plate of the scroll compressor. It is the figure which showed the item of the said scroll compressor, (a) is a top view of the said thrust plate, (b) is a figure of the graph for demonstrating the difference in the amount of oil supply by rotor rotation speed, (c) is It is AA arrow sectional drawing in (a). It is a fragmentary longitudinal cross-section of the part containing the thrust plate of the said scroll compressor. It is a top view of the thrust plate of the scroll compressor in Embodiment 2 and Embodiment 3 of this invention.

Embodiment 1 FIG.
FIG. 1 is a longitudinal sectional view of a scroll compressor according to Embodiment 1 of the present invention.
In FIG. 1, a scroll compressor 100 according to this embodiment sucks the refrigerant circulating in the refrigerant circuit, compresses it to a high temperature and high pressure state, and discharges it. The scroll compressor 100 is engaged with the main body container 1 which is a closed container, the fixed scroll 9 which is fixedly arranged at the upper part in the main body container 1 and has the spiral teeth 9a on the lower surface, and the spiral teeth 9a of the fixed scroll 9. A swinging scroll 10 having spiral teeth 10a forming the compression chamber 26 formed on the upper surface and having a boss portion 10d on the lower surface, and a swinging engagement with the swinging bearing 13 of the boss portion 10d of the swing scroll 10 are rotatably engaged. A rotation shaft 4 having an oil passage hole 4c formed in the upper end of the core shaft portion 4a and communicating with the inside of the shaft, a thrust support surface 11c for supporting the orbiting scroll 10, and a container radius more than the thrust support surface 11c. A concave portion 11b that is formed on the inner side in the direction and accommodates the boss portion 10d of the orbiting scroll 10, and a main portion that is formed in the lower portion of the concave portion 11b and pivotally supports the rotation drive shaft 4. A frame 11 having a receiving part 12 and fixedly arranged on the inner peripheral surface of the intermediate container 1a of the main body container 1, and a sliding surface part 10c on the lower surface of the orbiting scroll 10 and a thrust support surface 11c of the frame 11 are arranged. The ring plate-like thrust plate 14 that slidably supports the sliding surface portion 10c of the orbiting scroll 10 and the pump shaft 4b at the lower end of the rotary drive shaft 4 are provided on the lower container 1c of the main body container 1. And an oil pump 22 that pumps up the lubricating oil Y accumulated in the bottom and sends it to the oil passage hole 4c.

The scroll compressor 100 includes a compression unit including the fixed scroll 9 and the swing scroll 10 and a driving unit including the electric rotary machine 7 and the like. The compression unit and the drive unit are accommodated in the main body container 1. The main body container 1 is a sealed container in which an upper container 1c and a lower container 1b are provided on the upper and lower parts of the intermediate container 1a. The lower container 1b is an oil sump 23 for storing lubricating oil. A suction pipe 24 for sucking refrigerant gas is connected to the intermediate container 1a. A discharge pipe 25 for discharging refrigerant gas is connected to the upper container 1c.

The compression unit is composed of a rocking scroll 10, a fixed scroll 9, a frame 11, and the like. The swing scroll 10 is disposed on the lower side, and the fixed scroll 9 is disposed on the upper side. In addition, a thrust plate 14 that supports the swing scroll 10 is provided between the swing scroll 10 and the frame 11. A thrust bearing is configured by the rocking scroll 10 and the thrust plate 14 being in close contact with each other via lubricating oil. The thrust plate 14 also has a function of adjusting the gap in the container axis C direction in the compression chamber 26.

The fixed scroll 9 is formed with spiral teeth 9a erected on the lower surface of the base plate 9c. The swing scroll 10 is also provided with spiral teeth 10a that are erected on the upper surface of the base plate 10b and have substantially the same shape as the spiral teeth 9a. The orbiting scroll 10 and the fixed scroll 9 are mounted in the main body container 1 with the spiral teeth 10a and the spiral teeth 9a being combined with each other. In the state where the swing scroll 10 and the fixed scroll 9 are combined, the winding directions of the spiral teeth 9a and the spiral teeth 10a are opposite to each other. And between the spiral tooth 10a and the spiral tooth 9a, the compression chamber 26 in which the volume changes relatively is formed. The fixed scroll 9 and the orbiting scroll 10 are provided with

seals

27 and 28 on the spiral teeth 9a and the distal surfaces of the spiral teeth 10a in order to reduce refrigerant leakage from the distal surfaces of the spiral teeth 9a and the spiral teeth 10a. Yes.

The fixed scroll 9 is fixed to the opening edge of the upper surface of the frame 11 with a bolt (not shown). A discharge port 9b is formed at the center of the fixed scroll 9 to discharge the compressed refrigerant gas having a high pressure. The discharge port 9b is closed at 29 so as to be freely opened and closed. Then, the compressed refrigerant gas having a high pressure is discharged into a discharge space 33 provided in the upper part of the fixed scroll 9. The orbiting scroll 10 performs a revolving orbiting motion (oscillating motion) without rotating about the fixed scroll 9 by an Oldham ring 15 for preventing the rotating motion. Further, a hollow cylindrical rocking bearing 13 is formed at a substantially central portion of the sliding surface portion 10c that is the side surface opposite to the surface on which the spiral teeth 10a of the rocking scroll 10 are formed.

A slider 16 is rotatably inserted into the rocking bearing 13, and an eccentric shaft portion 4 a provided at the upper end of the rotary drive shaft 4 is inserted into the slide surface of the slider 16. The inner peripheral part of the rocking bearing 13 and the outer peripheral part of the slider 16 are slidably in close contact with each other via the lubricating oil to constitute the rocking bearing part. The drive unit includes a rotation drive shaft 4 that is a rotation shaft, a rotor 3 fixed to the rotation drive shaft 4, a stator 2 fixed to the inner peripheral surface of the intermediate container 1a, and the like. The rotor 3 is rotationally driven when the energization of the stator 2 is started to rotate the rotational drive shaft 4. That is, the electric rotating machine 7 is constituted by the stator 2 and the rotor 3.

The rotary drive shaft 4 rotates with the rotation of the rotor 3 to turn the orbiting scroll 10. The upper portion of the rotary drive shaft 4 (position near the eccentric shaft portion 4a) is supported by a main bearing portion 12 provided on the frame 11. A sleeve 17 is provided between the main bearing portion 12 and the rotary drive shaft 4 to smoothly rotate the rotary drive shaft 4. On the other hand, the lower portion of the rotary drive shaft 4 is rotatably supported by a ball bearing 21. The ball bearing 21 is press-fitted and fixed to a bearing housing portion 20a formed at the center portion of the subframe 20 fixed to the inner peripheral surface of the lower portion of the intermediate container 1a. Further, the subframe 20 is provided with a positive displacement oil pump 22. A pump shaft 4 b that transmits rotational force to the oil pump 22 is formed integrally with the rotary drive shaft 4. The lubricating oil Y sucked by the oil pump 22 is sent to each sliding portion through an oil passage hole 4c formed inside the rotary drive shaft 4. A first balancer 18 is attached to the outer periphery of the rotational drive shaft 4 immediately below the frame 11, and a second balancer 19 is attached to the outer periphery of the rotational drive shaft 4 immediately below the rotor 3 and covered by the second balancer cover 8. Yes.

As shown in FIGS. 2, 3, and 4 (a), the upper surface 14 a of the thrust plate 14 has an oil passage groove 40 that connects the inner peripheral surface 14 b and the outer peripheral surface 14 c of the thrust plate 14. Is formed. The oil passage groove 40 is formed in an “arc shape” along a circular arc from the outermost side to the innermost side in the container radial direction rr (see FIG. 2) in the rocking locus circle 41 of the rocking scroll 10 in a plan view. ing. The oil passage groove 40 is always in communication from the inner peripheral surface 14 b to the outer peripheral surface 14 c of the thrust plate 14. The lubricating oil Y is caused to flow out from the space on the back surface (lower surface) of the orbiting scroll 10 to the outside of the base plate 10 b of the orbiting scroll 10.

Next, the operation will be described.
In the scroll compressor 100 configured as described above, when a voltage is applied to the electric rotary machine 7, a current flows through the electric wire portion of the stator 2 to generate a magnetic field. This magnetic field works to rotate the rotor 3, and the rotary drive shaft 4 is rotationally driven together with the rotor 3. When the rotary drive shaft 4 is driven to rotate, the slider 16 also rotates within the rocking bearing 13 via the eccentric shaft portion 4a. The swing scroll 10 whose rotation is suppressed by the Oldham ring 15 performs swing swing motion. As a result, part of the refrigerant gas flows into the compression chamber 26 via the suction port (not shown) of the frame 11 and the suction process is started. Further, the remaining part of the refrigerant gas cools the electric rotary machine 7 and the lubricating oil Y through the notch portion of the steel plate of the stator 2.

The compression chamber 26 is gradually moved to the center of the orbiting scroll 10 by the orbiting motion of the orbiting scroll 10, and the volume is further reduced. Through this step, the refrigerant gas sucked into the compression chamber 26 is compressed. At this time, a load is applied to the swing scroll 10 by the compressed refrigerant gas so as to move away from the fixed scroll 9 in the direction of the axis C. This load is supported by a thrust plate 14 (thrust bearing). The compressed refrigerant passes through the discharge port 9 b of the fixed scroll 9, pushes the discharge valve 29 open, and flows into the discharge space 33. Then, it is discharged from the main body container 1 through the discharge pipe 25 to the refrigerant circuit. The lubricating oil Y sucked up to the slider 16 by the oil pump 22 is a sliding portion between the bearing metal of the orbiting scroll 10 and the slider 16, a sliding surface portion 10 c of the orbiting scroll 10, and the upper surface of the thrust plate 14. Lubricate the sliding part. Thereafter, the lubricating oil Y falls from the inside of the frame 11 through the oil draining pipe 11a and is returned to the oil sump 23 at the bottom of the main body container 1.

Here, a part of the lubricating oil Y that lubricates the sliding portion between the thrust surface of the orbiting scroll 10 and the thrust surface of the frame 11 is caused to flow out of the thrust surface and sucked into the compression chamber 26. It is also necessary to use for lubrication against the sliding of the spiral teeth. That is, a part of the lubricating oil Y sent from the oil passage hole 4 c of the rotary drive shaft 4 into the recess 11 b of the frame 11 is slidable between the thrust support surface 11 c of the frame 11, the thrust plate 14, and the orbiting scroll 10. It passes from the outside through the surface portion 10 c and rises to flow into the spiral teeth 10 a of the orbiting scroll 10.

The back space of the orbiting scroll 10 in the frame 11 is filled with lubricating oil Y, and the oil pressure depends on the pump discharge pressure by the oil pump 22 (see FIG. 5). This lubricating oil Y is pushed outward in the radial direction through the oil passage groove 40 by the differential pressure between the boss portion 10d and the concave portion 11b, and is supplied to the outside of the base plate 10b of the orbiting scroll 10 ("differential pressure" Refueling "). On the other hand, the thrust plate 14 has a central opening 14d at the center of the plane, and has

claw portions

14e and 14e on the outer peripheral edge (see FIG. 2). These

claw portions

14e and 14e enter the suction hole 11d of the frame 11 to serve as a rotation stopper.

The oil passage groove 40 swings the rocking scroll 10 so that the rocking motion of the rocking scroll 10 causes the effect of carrying the lubricating oil Y inward from the outer peripheral side (so-called “viscous pump effect”). In the middle of the oil passage groove 40 of the thrust plate 14, the rocking scroll 10 is formed in an arcuate shape along a rocking locus circle 41 when the rocking scroll 10 moves inward from the outer peripheral side. As a result, when the orbiting scroll 10 slides around the oil passage groove 40 of the thrust plate 14 around the arrow T (see FIG. 3), the orbiting scroll 10 moves inwardly from the outer peripheral surface 14c side of the thrust plate 14. Lubricating oil Y in the oil passage groove 40 that the sliding surface portion 10c of the orbiting scroll 10 tries to adhere to the sliding surface portion 10c of the orbiting scroll 10 due to surface tension only in the movement groove 40 is moved. It creates a viscous pump effect that pulls inward.

As shown in FIG. 4B, the viscous pump effect by the oil passage groove 40 is larger as the rotational speed is higher, and the effect is less at a low rotational speed.
That is,
At low speed: “Oil supply amount” = “Differential pressure oil supply”;
At high speed: “Oil supply amount” = “Differential pressure oil supply”-“Viscous pump effect”
It becomes.

Therefore, the oil passage groove 40 is formed at a low rotation speed at which the

spiral teeth

9a, 10a are likely to be worn by sliding between the side surfaces of the

spiral teeth

9a, 10a of the fixed scroll 9 and the orbiting scroll 10 made of cast iron material, for example. The amount of oil supplied through increases, and conversely, the amount of oil supplied increases and the amount of oil circulating in the refrigerant tends to increase. Not too much.

The viscous pump effect by the oil passage groove 40 is the largest when the curvature R of the oil passage groove 40 is an arc shape so that the crank radius r of the rocking locus circle 41 of the rocking scroll 10 becomes. . Further, as the depth hg of the oil passage groove 40 is reduced, the viscous pump effect is increased and the amount of oil supplied by differential pressure oil supply is reduced, so that the amount of oil supplied at a high rotational speed can be suppressed (see FIG. 4B).

Between the frame 11 and the thrust plate 14, there is a backlash between the

claw portions

14e, 14e and the suction hole 11d, and a backlash between the inner peripheral surface of the frame 11 and the outer peripheral surface 14c of the thrust plate 14. On the other hand, the oil passage groove 40 is always in communication. As a result, the amount of oil passage does not vary due to the play.

A plurality of oil passage grooves 40 may be provided for each thrust plate 14 for the purpose of adjusting the amount of oil supply. For example, when two oil passage grooves 40 are to be formed on the opposite side 180 degrees around the axis C of the rotational drive shaft 4, the first oil passage groove 40 is point-symmetric with respect to the center C of the thrust plate 14. A second oil passage groove 40 (not shown) may be formed at a position moved 180 degrees.

Embodiment 2. FIG.
In the above embodiment, the circular oil passage groove 40 is illustrated in plan view, but the oil passage groove of the present invention is not limited thereto. For example, as shown in FIG. 6, the oil passage groove 40 </ b> A is formed in a dogleg shape in plan view. Even in this case, the viscous pump effect works well if the “shape” is along the shape inward from the outermost part of the swing scroll radial direction of the swing scroll circle 41 of the swing scroll 10. .

DESCRIPTION OF SYMBOLS 1 Main body container 4 Rotation drive shaft 4a Eccentric shaft part 4c Oil passage hole 9 Fixed scroll 9a Swirl tooth 10 Swing scroll 10a Swirl tooth 10c Sliding surface part 10d Boss part 11 Frame 11b Recessed part 11c Thrust support surface 12 Main bearing part 13 Swing Dynamic bearing 14 Thrust plate 14a Upper surface 14b Inner peripheral surface 14c Outer peripheral surface 22 Oil pump 26

Compression chamber

40, 40A Oil passage groove 41 Oscillating locus circle 100 Scroll compressor C Shaft center R Curvature r Radius Y Lubricating oil

Claims

A main body container which is a sealed container;
A fixed scroll that is fixedly deployed in the upper part of the main body container and has spiral teeth on the lower surface;
An orbiting scroll having a boss portion on the lower surface, the spiral teeth forming the compression chamber meshing with the spiral teeth of the fixed scroll,
A rotary drive shaft having an oil passage hole which is formed at an upper end portion of an eccentric shaft portion rotatably engaged with a rocking bearing of a boss portion of the rocking scroll and communicates vertically with the shaft;
A thrust support surface for supporting the orbiting scroll; a recess formed inside the radial direction of the container with respect to the thrust support surface to store a boss portion of the orbiting scroll; and a rotary drive formed at a lower portion of the recess. A frame having a main bearing portion pivotally supporting a shaft and fixedly arranged on an inner peripheral surface of the main body container;
A ring plate-shaped thrust plate that is disposed between the lower surface of the swing scroll and the thrust support surface of the frame and slidably supports the lower surface of the swing scroll;
An oil pump that is provided at the lower end of the rotary drive shaft and pumps up the lubricating oil accumulated at the bottom of the main body container and sends it to the oil passage hole;
A portion of the lubricating oil sent from the oil passage hole of the rotary drive shaft into the recess of the frame passes between the thrust support surface of the frame, the thrust plate, and the sliding surface portion of the bottom surface of the orbiting scroll. Through the swirl teeth of the orbiting scroll,
A scroll compressor characterized in that an oil passage groove is formed on the upper surface of the thrust plate to communicate the inner peripheral surface and the outer peripheral surface of the thrust plate.
2. The oil passage groove is formed in an arc shape along a circular arc extending from the outermost part to the innermost part in the rocking scroll radial direction in the rocking locus circle of the rocking scroll in a plan view. Scroll compressor described in 1.
The oil passage groove is formed in a square shape along an arc extending from the outermost side to the innermost side in the radial direction of the orbiting scroll in an orbiting circle of the orbiting scroll in plan view. The scroll compressor according to 1.