JPH04325791A - Scroll compressor - Google Patents

Abstract

PURPOSE:To reduce the surface pressure of a clearance part formed by the tooth tip part of a fixed scroll lap and the corresponding tooth bottom part of a turning scroll so as to prevent a galling phonomenon by forming this tooth tip-bottom clearance larger than that in the other region. CONSTITUTION:A tooth tip-bottom clearance formed by the tooth tip part corresponding to the winding end half winding of the spiral lap of a fixed scroll 2 and the corresponding tooth bottom part of a turning scroll 3 is formed larger than a clearance formed between the tooth tip and the tooth bottom in the other region. For instance, the tooth tip part 22 corresponding to the winding end half winding of the spiral lap of the fixed scroll 2 and an end plate 35, which is the corresponding tooth bottom part of the turning scroll 3, are provided with step difference formed deeper by 15-20mum compared to the other tooth bottom part, and this step difference is formed into an oil sump. Or the tooth tip corresponding to the approximate half winding from the winding end of the fixed scroll lap is formed lower by 15-20mum compared to the other region.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention involves eccentrically engaging the spiral wrap portion of a fixed scroll member and the spiral wrap portion of an orbiting scroll member, and causing the spiral wrap portion of the orbiting scroll member to revolve. The present invention relates to a scroll compressor that discharges compressed fluid from the center by reducing the volume while moving the closed space formed between both spiral wrap portions toward the center.

0002

[Prior Art] A conventional scroll compressor is
As described in JP-A-119412 and JP-A-55-37520, the seat surface 31, which is the contact surface between the end plates of the fixed scroll 2 and the orbiting scroll 3, is formed into a ring shape with the same width all around. ing. Therefore, uniform surface pressure is always maintained and a stable sealing effect is obtained. In addition, the width 34 of the seat surface 31 which is a ring-shaped sliding surface
is formed to be smaller than the orbiting diameter so that when the contact surface moves, the original contact surface is completely exposed to the oil atmosphere and the upper surface of the end plate 35 of the orbiting scroll is sufficiently wetted with oil. Therefore, when the contact surface returns to the next original position due to the orbiting movement of the orbiting scroll, sufficient oil can be supplied. Since the groove 33 provided in the fixed scroll 2 is formed as an annular groove around the entire circumference, while the orbiting scroll 3 is making an orbiting movement, the outer circumference of the end plate 35 is formed by the groove 33 and the frame 5. It enters and leaves the annular space 37.

On the other hand, the oil supplied to the upper main bearing 12 and the thrust bearing 40 through the oil hole 19 and the oil supplied to the slewing bearing 8 flow into the back pressure chamber 16, which eventually becomes full and further into the annular space 37. Oil also flows in and wets the upper surface of the end plate 35 of the orbiting scroll 3 with oil.

0004

[Problems to be Solved by the Invention] However, when machining the outer diameter portion 21 of the fixed scroll 2 at the end radius of the spiral, if the wall thickness t of the spiral is the same, the dimensions of the outer shallow groove 36 are determined by the end mill being machined. It is determined by the diameter of the cutting tool, and if the diameter is made small, it takes time to process, and if the diameter is made large, the outer diameter of the fixed scroll 2 becomes large. For this reason, the outer diameter of the last half turn of the fixed scroll 2 is set to a radius r from the center of the fixed scroll 2, as shown in 20 in FIG. The outer diameter of the fixed scroll 2 is reduced to a minimum, and the workability is improved. However, with this shape, the wall thickness t of the spiral becomes large, and some parts are larger than the turning diameter, which leads to poor lubrication conditions and a galling phenomenon that occurs in this part when combined with severe operating conditions. Ta.

[0005] In other words, gas does not flow to the half-turn part from the winding end of the fixed scroll wrap, and sufficient lubrication is not achieved.
Under harsh conditions where both members are strongly pressed in the axial direction, the tips of the teeth of the fixed scroll wrap and the bottoms of the orbiting scroll teeth could experience abnormal wear and seizure, which significantly reduced reliability. .

[0006] An object of the present invention is to provide a scroll compressor which can reduce the surface pressure of the above-mentioned portions, prevent galling, and improve reliability withstanding severe operating conditions.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the scroll compressor of the present invention has a tooth tip portion corresponding to a half turn from the winding end of a fixed scroll wrap, and a tooth bottom portion of an orbiting scroll corresponding to the tooth tip portion corresponding to a half turn from the winding end of a fixed scroll wrap. The gap between the tooth tip and the tooth bottom formed in one area is larger than the gap formed between the tooth tip and the tooth bottom in other areas.

[0008] Furthermore, the tooth thickness of the portion that contacts the bottom surface of the orbiting scroll is thinner than the tooth thickness of other portions of the portion corresponding to approximately half a turn from the winding end of the fixed scroll wrap. .

[0009]

[Operation] The gap between the tooth tip and tooth bottom formed by the tooth tip part corresponding to half a turn from the winding end of the fixed scroll wrap and the corresponding tooth bottom part of the orbiting scroll is Since this area is set to be larger than the gap formed by the bottom of the tooth, this area acts as an oil reservoir.By providing an oil reservoir in this way, lubrication is ensured and the surface pressure in this area is reduced. This prevents the galling phenomenon. In addition, in the above portion, the pressure difference between the compression chambers is small, so the leakage rate is small and performance deterioration is small.

[0010] Furthermore, the tooth thickness of the portion that contacts the bottom surface of the orbiting scroll is thinner than the tooth thickness of other portions of the portion corresponding to approximately half a turn from the winding end of the fixed scroll wrap. The contact surfaces of the tips of the teeth with the bottom surface of the orbiting scroll are constantly exposed to oil contained in the width of the refrigerant gas during movement due to the orbiting motion, and become wet with oil.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below with reference to FIGS. 1 to 5.

The scroll compressor shown in FIG. 1 has a compressor section and an electric motor section housed in a closed container 1. In the compressor section, a fixed scroll 2 and an orbiting scroll 3 are engaged with each other to form a compression chamber 9 (sealed space). The fixed scroll 2 consists of a disc-shaped end plate and a spiral wrap formed by an involute curve or a curve approximating the involute curve, and has a discharge port 10 in the center and an inlet port on the outer periphery. It is equipped with 4. The orbiting scroll 3 includes a disk-shaped end plate, a spiral wrap 3a standing upright thereon and formed in the same shape as the spiral wrap 2a of the fixed scroll 2, and a spiral wrap 3a formed on the opposite side of the end plate. It consists of 25 bosses. A bearing portion 26 is formed in the center of the frame 5, and the rotating shaft 7 is supported by this bearing portion 26. The eccentric shaft 7b at the tip of the rotating shaft 7 is inserted into the boss 25 of the orbiting scroll 3 so as to be able to rotate. Further, a fixed scroll 2 is fixed to the frame 5 with a plurality of bolts, and an orbiting scroll 3 is fixed to an Oldham ring 2.
7. The orbiting scroll 3 is supported by the frame 5 by an Oldham mechanism consisting of an Oldham key, etc., and is formed to orbit the fixed scroll 2 without rotating. An electric motor shaft is integrally connected to the rotating shaft 7 at the lower part thereof, and an electric motor section (consisting of a stator 14 and a rotor 15) is provided.
are directly connected. The suction port 4 of the fixed scroll 2 is connected to the closed container 1 through it.

In the scroll compressor having the above structure, the eccentric shaft 7b rotates eccentrically due to the rotation of the rotating shaft 7 directly connected to the electric motor, so that the orbiting scroll 3 makes an orbiting motion via the boss. Due to this swirling movement, the compression chamber 9 gradually moves to the center and its volume decreases. The gas enters the compression chamber 9 through the suction port 4, is compressed as described above, is discharged from the discharge port 10 into the discharge chamber 11, and is discharged from a discharge pipe (not shown) connected through the closed container 1. Ru.

The operation of the compressor will be explained according to the flow of refrigerant gas and the flow of lubricating oil. The low-temperature, low-pressure refrigerant gas is guided from the suction port 4 and reaches the outermost chamber 32 of the fixed scroll 2 . The refrigerant gas that has reached the compression chamber 9 moves to the center of the scroll as the closed space formed by both scrolls 2 and 3 gradually shrinks due to the orbiting movement of the orbiting scroll, which is prevented from rotating. is discharged from the central discharge hole 10. The discharged high-temperature, high-pressure refrigerant gas passes through the upper space 11a in the closed container 1 and the passage guide 6, and then fills the lower space 11b around the electric motor.
It is guided to the outside via a discharge pipe that penetrates and connects the closed container 1.

On the other hand, a space 16 (referred to as a "back pressure chamber") surrounded by the back surface of the orbiting scroll 3 and the frame 5 includes a plurality of sealed spaces formed by both the orbiting and fixed scrolls 2 and 3. In order to counter the gas force in the thrust direction due to the gas pressure inside (this force becomes a separation force that tries to push down the orbiting scroll 3), the pressure between the suction pressure (low pressure side pressure) and the discharge pressure is act. This intermediate pressure is achieved by providing a pore 17 in the end plate of the orbiting scroll 3, guiding the gas inside the scroll to the back pressure chamber 16 through the pore, and causing the gas to act on the back surface of the orbiting scroll. How to apply this intermediate pressure is disclosed in JP-A-53-119412 and JP-A-55-37520, so a detailed explanation will be omitted.

Next, the flow of lubricating oil will be explained.

The lubricating oil 23 is stored in the lower part of the closed container 1. The lower end 7a of the main shaft 7 is immersed in oil 23 at the bottom of the container,
An eccentric shaft portion 7b is provided at the upper portion of the main shaft, and the eccentric shaft portion 7b engages with the orbiting scroll 3, which is a scroll compression element portion, via a rotation boss. The main shaft 7 and the eccentric shaft 7b are provided with eccentric vertical holes 18 and 19 for supplying oil to each bearing part.
It is formed from the lower end of the eccentric shaft 7b to the upper end surface of the eccentric shaft 7b. A balance weight 28 is formed at the lower part of the eccentric shaft portion 7b so as to be engaged with and integrated with the rotating shaft 7. The lower end 7a of the main shaft immersed in the lubricating oil 23 is in an atmosphere of high discharge pressure Pd, while the area around the bearing part 8 of the pivot boss on the downstream side is
Since the atmosphere is at an intermediate pressure Pm, the lubricating oil 23 at the bottom of the container flows through the eccentric vertical hole 18, due to the pressure difference (Pd-Pm).
It rises within 19. Furthermore, due to the rotation of the main shaft, centrifugal force acts on the oil in the eccentric vertical holes 18 and 19, further increasing the amount of oil supplied to each bearing. In this way, each bearing portion is supplied with oil by eccentric hole oil supply and differential pressure oil supply. The lubricating oil rising inside the eccentric vertical holes 18 and 19 flows into the bearings 12 and 19.
13 and the upper space 24 of the eccentric shaft portion 7b.
(The bottom surface of the boss part of the orbiting scroll boss 25 and the eccentric shaft part 7
The space in the gap with the upper end surface of b becomes a hydraulic chamber. Hereinafter, it will be referred to as the "hydraulic chamber" 24. ). The hydraulic chamber 24
The lubricating oil has a pressure approximately equal to the discharge pressure Pd, and the lubricating oil that has reached the bearing of the swing boss and the bearings 12 and 13 is discharged into the back pressure chamber 16 through the respective bearing gaps. The lubricating oil that has reached the back pressure chamber 16 lubricates the Oldham mechanism and the like, and then is injected into the compression chamber 9 formed by both scrolls through the seat surfaces 35 of the fixed scroll 2 and the orbiting scroll 3 and the pores 17. Thereafter, it is mixed with the refrigerant gas inside the scroll spiral.

The orbiting scroll 3, which has received intermediate pressure in the back pressure chamber 16, is pressed against the fixed scroll 2 so as not to separate from it. The pressure generated at this time is shared by the end plate 35 of the orbiting scroll 3, the seat surface 31 of the fixed scroll 2, and the tip surface of the spiral. Lubrication of the sliding surface that takes charge of these pressing forces is carried out by the seat surface 3, which is a ring-shaped sliding surface.
The width 34 of 1 and the width t of the tooth tip of the spiral wrap are formed to be smaller than the turning diameter, so that when the contact surface moves, the original contact surface is completely exposed to the oil atmosphere and wetted with oil. There is.

However, when processing the outer diameter portion 21 of the half-turn at the end of the spiral wrap of the fixed scroll 2, if the wall thickness t of the spiral wrap is kept the same, the dimensions of the outer shallow groove 36 are as follows. Determined by the diameter of the end mill tool to be processed. In other words, if the diameter is made smaller, it will take more time to process, and if it is made larger, the outer diameter of the fixed scroll 2 will become larger.
As shown in 0, the fixed scroll 2 is set at a radius r from the center, and lathe processing is performed to reduce the radial width of the shallow groove 36 to the necessary minimum, thereby reducing the outer diameter of the fixed scroll 2 and improving workability. We are trying to However, with this shape, the wall thickness t of the spiral becomes large, and the contact surface is not completely exposed to the oil atmosphere, resulting in poor oil supply conditions. As a result, there was a defect in that galling occurred in this part when severe operating conditions were encountered.

The present invention provides a portion 2 shown in FIG. 3 in which the half-turn portion at the end of the spiral wrap of the fixed scroll 2 shown in FIG.
It is 2. The end plate 35 of the orbiting scroll 3 has a thickness of 15 to 20 μm.
It has a deep step, and this part is used as an oil reservoir. By providing an oil reservoir in this manner, the oil supply can be more reliably performed, and the surface pressure in this area can be reduced to prevent galling, thereby improving reliability withstanding severe operating conditions.

Another embodiment of the invention is shown in FIG. As shown in FIG. 4, the half-turn portion 50 at the end of the spiral wrap of the fixed scroll 2 has a tooth height of 15 to 2 compared to other portions.
It may be lowered by 0 μm. In this case, since the contact with the bottom surface of the orbiting scroll 3 can be alleviated, similar effects such as prevention of seizure and avoidance of the galling phenomenon can be obtained.

Still another embodiment of the present invention will be explained with reference to FIG. Outer portions 51 of the tooth tips are wrapped so that only the tooth tips have a thickness equal to or less than that of the other wrap portions in the outer diameter portion of the fixed scroll 2 that is approximately half a turn from the end of the winding. lower than other parts, e.g. 10-15
By reducing the tooth tip to the bottom surface of the orbiting scroll, the contact surface of the tooth tip with the bottom surface of the orbiting scroll is always exposed to the oil contained in the refrigerant gas width when moving by orbiting motion, and becomes wet with oil. Therefore, the lubrication of the contact surfaces is maintained, and seizure and jamming can be avoided.

[0023]

[Effects of the Invention] Since the present invention is constructed as described above, the tooth tips of the fixed scroll wrap and the tooth bottoms of the orbiting scroll wrap do not wear or seize, and lubrication can be reliably performed, improving reliability. can do.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a scroll compressor that is an embodiment of the present invention.

FIG. 2 is a plan view of the fixed scroll 2 viewed from the spiral side.

FIG. 3 is a plan view of the orbiting scroll 3 viewed from the spiral side.

FIG. 4 is a plan view of the fixed scroll 2 viewed from the spiral side.

FIG. 5 is a plan view of the fixed scroll 2 viewed from the spiral side.

[Explanation of symbols]

1... Airtight container, 2... Fixed scroll, 3... Orbiting scroll, 9... Compression chamber, 22, 50, 51... Stepped portion.

Claims (7)

[Claims] Claim 1: A fixed scroll member having a spiral wrap formed upright on an end plate and a wrap of an orbiting scroll member are engaged with each other inwardly, and a boss portion of the orbiting scroll member is connected to a rotating shaft supported on a frame. The orbiting scroll member is engaged with the eccentric shaft portion of the scroll member, and the orbiting scroll member is rotated relative to the fixed scroll member without rotating on its own axis by the Oldham mechanism. In a scroll compressor, a fixed scroll and an orbiting scroll are combined in a scroll compressor that compresses gas by moving a sealed space formed by The gap between the tooth tip and the tooth bottom formed by the tooth tip portion corresponding to approximately half a turn from the winding end of the fixed scroll wrap and the corresponding tooth bottom portion of the orbiting scroll in the fixed scroll wrap state is other area. A scroll compressor characterized in that the gap is larger than the gap formed between the top and the bottom of the teeth. 2. A tooth tip portion corresponding to approximately half a turn from the winding end of the fixed scroll wrap and a tooth bottom portion of the orbiting scroll corresponding thereto are deeper than other tooth bottom portions. scroll compressor. 3. The scroll compressor according to claim 2, wherein the tooth bottom portion of the orbiting scroll is 15 to 20 μm deeper than tooth bottom portions in other areas. Claim 4: Claim 1 in which the tip of the fixed scroll wrap, which corresponds to approximately half a turn from the end of the winding, is lower than other areas.
Scroll compressor described in . 5. The scroll compressor according to claim 4, wherein the tip of the fixed scroll is 15 to 20 μm lower than the tip of the tooth in other areas. 6. The wraps of the fixed scroll member and the orbiting scroll member, each having a spiral wrap formed upright on the end plate, are engaged with each other inwardly, and the boss portion of the orbiting scroll member is connected to a rotating shaft supported by a frame. The orbiting scroll member is engaged with the eccentric member located in the center of the fixed scroll member, and the orbiting scroll member is caused to rotate relative to the fixed scroll member without rotating on its own axis by the Oldham mechanism. In a scroll compressor that compresses gas by moving a sealed space formed in a central direction to reduce the volume and discharge the compressed gas from a discharge port provided in the center, the end of the fixed scroll wrap is used. A scroll compressor characterized in that the tooth thickness of a portion that contacts the bottom surface of the orbiting scroll is thinner than the tooth thickness of the other portion of the portion corresponding to approximately half a turn from the end. 7. The outer portion of the wrap is separated from the other wrap portions so that the thickness of the tooth tip in a portion corresponding to approximately half a turn from the end of the orbiting scroll winding is thinner than the wrap thickness in other portions. The scroll compressor according to claim 6, wherein the scroll compressor is configured to be lower than the tooth height.