JPH0754784A - Shaft through scroll compressor - Google Patents

Abstract

PURPOSE:To reduce a sliding loss or the like in a bearing part by extending an axial center shaft part in the eccentric shaft point end of a crankshaft to a delivery hole inside in a fixed scroll side, and arranging a bearing for supporting the axial center shaft part in an opposite lap side of a fixed scroll. CONSTITUTION:A main bearing 40 is arranged in the central part of a frame 11 for fixing a fixed scroll 5. A turn bearing 31 is arranged in the center part of a turning scroll 6. Further, an eccentric shaft part 14a of a crankshaft 14 is inserted to the turn bearing 31, and an axial center shaft part 14f is extended to a side of the fixed scroll 5 in a point end of the eccentric shaft part 14a. Here, the axial center shaft part 14f is extended to the inside of a delivery hole 10 in the central part in a side of the fixed scroll 5. A bearing 32 for supporting the axial center shaft part 14f is arranged in an opposite lap side of the fixed scroll 5. On the other hand, a thrust bearing 33 for supporting the crankshaft 14 is arranged in an end part of the axial center shaft part 14f.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetic scroll compressor used as a refrigerant compressor for refrigeration and air conditioning, refrigerators and the like.

[0002]

2. Description of the Related Art A shaft penetrating scroll compressor is disclosed in
As disclosed in Japanese Laid-Open Patent Publication No. 57-131896, an orbiting bearing portion is provided in the center of an orbiting scroll member, and the eccentric shaft portion of the crankshaft is inserted into the orbiting bearing portion up to the tip of the wrap, and the crankshaft is eccentric. Extend the shaft axis further to the tip,
This is a structure in which a bearing portion for supporting the shaft center shaft portion is formed on the fixed scroll side.

[0003]

In the above-mentioned known technique, the bearing portion for supporting the shaft center shaft portion is provided on the fixed scroll side, but it is arranged on the end plate portion of the fixed scroll. For this reason, the discharge refrigerant gas passage is restricted by the size of the discharge hole, and the discharge refrigerant gas passage cannot be wide, and the discharge passage has a refraction passage shape as in the cited example. The loss (pressure loss) greatly increased, which was disadvantageous in terms of compressor performance. Further, sliding bearings are arranged on both the frame side and the bearings arranged in the end plate portion of the fixed scroll so as to sandwich the orbiting bearing arranged at the center of the orbiting scroll member. Since the temperature around these bearings is high, there is a problem that the above-mentioned bearing specifications have a high coefficient of friction and inferior reliability with respect to oil shortage at the time of starting the compressor.

[0004]

As shown in FIGS. 1 to 4, according to the present invention, a fixed scroll member and an orbiting scroll member for upstanding a spiral wrap on a disk-shaped end plate are meshed with the wrap inside. The orbiting scroll member is orbitally moved with respect to the fixed scroll member without rotating, and the fixed scroll member is provided with a discharge hole opening at the center and an inlet opening at the outer peripheral portion, and sucks gas from the inlet. A main bearing is provided in the center of the frame that fixes the fixed scroll member by moving the compression space formed by both scroll members to reduce the volume and compress the gas. A bearing portion is provided, and the eccentric shaft portion of the crankshaft is inserted into the orbiting bearing portion up to the tip of the wrap, and the crankshaft extends further to the fixed scroll side at the tip of the eccentric shaft. In the shaft-through scroll compressor, the shaft center shaft portion is extended inside the discharge hole provided in the central portion on the fixed scroll side, and the bearing portion supporting the extended shaft center shaft portion is arranged on the non-wrap side of the fixed scroll. In addition, the thrust bearing portion for supporting the crankshaft is formed at the end of the extension shaft core portion. Further, an inner sealing means is arranged in a thrust portion facing the frame in the central portion on the rear surface of the end plate of the orbiting scroll member, and an oil supply passage provided in the extension shaft core portion and the crankshaft is provided in an inner region of the inner sealing means. It is characterized in that high pressure oil is caused to act on the inside of the inner sealing means, and an atmosphere having an intermediate pressure between the discharge pressure and the suction pressure or the suction pressure is applied to the outer region of the inner sealing means. In particular,
An inner seal ring portion is provided in the thrust portion facing the center frame on the rear surface of the end plate of the orbiting scroll member, and high pressure oil is caused to act on the central portion on the back surface of the end plate of the orbiting scroll member. With respect to the area, the outer dimension Dod of the inner seal ring portion is approximately Dod / Ds with respect to the outer dimension Dso of the orbiting scroll end plate.
o It must be configured with a ratio of 0.5 or more.
In addition, a sliding bearing is provided as the orbiting bearing at the center of the orbiting scroll member, and a highly durable rolling bearing is arranged on the sub bearing that supports the extension shaft core and the frame side main bearing, and the thrust that supports the crankshaft is installed. A rolling thrust bearing is formed as a directional bearing portion at the end portion of the extension shaft core shaft portion. Further, the size of the discharge hole provided in the central portion on the fixed scroll side is set to be equal to or larger than the inner diameter dimension of the orbiting bearing portion.

[0005]

The operation of the present invention will be described with reference to FIG. In the present invention, a slide bearing is provided as the orbiting bearing portion 31 at the center of the orbiting scroll member 6, and the auxiliary bearing portion 32 supporting the extension shaft center shaft portion 14f and the frame side are provided so as to have a positional relationship of sandwiching the bearing portion 31. Since the main bearing 40 is provided with a highly durable rolling bearing, each rolling bearing 32, 4
At 0, because of the frictional action due to rolling contact, the friction coefficient at that portion is as small as around 0.0015. Therefore, the friction loss at both bearings 32 and 40 can be significantly reduced as compared with the conventional machine. Further, since the rolling thrust bearing 33 is formed at the lower end portion of the extension shaft core shaft portion 14f as a bearing portion in the thrust direction for supporting the crankshaft 14, the thrust bearing 33 can bear a load such as its own weight acting on the crankshaft 14. You can take charge. The shaft diameter of the thrust bearing 33 is set to be smaller than the crank shaft diameter of the main bearing part and the shaft diameter of the eccentric shaft part, and the sliding speed of the thrust bearing 33 becomes the smallest, and the friction loss due to the thrust load in that part is set. Can be minimized. In addition, since the entire crankshaft 14 is of the rolling support type, the bearing gap is controlled minutely and the behavior of the crankshaft system in the axial direction can be stabilized. Further, with respect to oil shortage at the time of starting the compressor, durability can be secured in the bearing portion even with a small amount of oil, which is advantageous in terms of reliability. Further, since the size of the discharge hole 10 provided in the central portion 5a of the end plate on the fixed scroll 5 side is set to be approximately the same as the inner diameter of the orbiting bearing portion 31, the passage area of the discharge hole 10 is smaller than that of the conventional machine. Widely secured from several times to around a dozen times. In this way, the sliding loss of the bearing can be reduced,
Further, since there is no refraction passage in the conventional machine, the discharge pressure loss can be greatly reduced in combination with the effect of the enlarged structure of the discharge port. As a result, the performance of the scroll compressor of the shaft penetration type can be greatly improved by the synergistic effect with the ripple effect such as the loss reduction of the leakage inside the compression chamber due to the stabilization of the behavior of the orbiting scroll due to the structure in which the overturning moment does not act. Further, the inner sealing means 34a is arranged in the thrust portion facing the frame 11 in the central portion on the rear surface of the end plate 6a of the orbiting scroll member 6, and the outer region of the inner sealing means 34a is set to an atmosphere of low pressure so that the inner sealing means 34a Due to the structure in which the high pressure oil is applied to the inner region set in a wide range through the extension shaft center shaft portion 14f and the oil supply passage 13 provided in the crankshaft 14, the differential pressure is mainly applied to the thrust peripheral portion 39. It can be ensured by the refueling method. Therefore, the surface pressure at the thrust sliding surface 39 is also reduced, the lubricity at the sliding portion is improved, the abrasion of the sliding portion is suppressed, and the seizure can be prevented. Thus, the reliability of the compressor as a whole can be improved.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention is shown in FIGS. FIG. 1 is a partial vertical sectional view of a hermetic scroll compressor, and FIGS. 2 and 3 are a plan view and a vertical sectional view of a fixed scroll 5. 4 and 5 are a plan view and a vertical sectional view of the orbiting scroll 6. This will be described with reference to FIGS. 1 to 5. In the figure, the solid line arrow indicates the flow direction of the refrigerant gas, and the broken line arrow indicates the flow direction of the oil. In FIG. 1, a sliding bearing is provided as the orbiting bearing portion 31 at the center of the orbiting scroll member 6. As the bearing portion 31, a relatively durable oil-impregnated bearing type or a dry type slide bearing in which tetrafluoroethylene resin is applied as a bearing material may be used. Bearing part 31
In such a positional relationship as to sandwich the rolling bearing, a sub-bearing portion 32 supporting the extension shaft core shaft portion 14f and a frame side main bearing 40 are provided with rolling bearings having high durability. Further, since the rolling thrust bearing 33 is formed at the lower end portion of the extension shaft core shaft portion 14f as a bearing portion in the thrust direction for supporting the crankshaft 14, the thrust bearing 33 can bear a load such as its own weight acting on the crankshaft 14. You can take charge. Thrust bearing 3
The shaft diameter of 3 is set smaller than the crank shaft diameter of the main bearing portion and the shaft diameter of the eccentric shaft portion. For example, the shaft diameter of the crankshaft 14 of the main bearing portion 40 is Ds = 35 mm, the shaft diameter of the eccentric shaft portion 14a is Dm = 25 mm, and the shaft diameter of the extension shaft central shaft portion 14f is Df.
= 15mm dimensional relationship. Also in this case,
The amount of eccentricity of the eccentric shaft portion 14a, that is, the turning radius (see FIG. 7) is set to a value around Eth = 4.5 mm. In this way, the sliding speed of the thrust bearing 33 is minimized,
The friction loss due to the thrust load at that portion can be suppressed to a minimum. An inner seal ring 34a is arranged in the thrust portion facing the frame 11 in the central portion on the rear surface of the end plate 6a of the orbiting scroll member 6. Inner seal ring 34a
The outer region of the orbit is set at an intermediate pressure between the discharge pressure and the suction pressure or an atmosphere at the suction pressure.
The diaphragm holes 6d and 6e that penetrate the end plate 6a are provided.
An outer sealing means 34b, for example, a ring-shaped seal ring, is arranged on the outer periphery of the rear surface of the swivel end plate 6a with respect to the suction chamber 5f, which is an atmosphere having a suction pressure which is an area outside the intermediate pressure atmosphere. The flow of oil to the thrust peripheral portion 39 such as the inner sealing means 34a will be briefly described with reference to FIG. The lubricating oil that has risen in the central vertical hole 13 via the oil supply pipe 23 connected to the lower end of the extension shaft 14f passes through the horizontal holes 13 (13a, 13b, 13c) and the orbiting bearing 31 and the seal bearing. 38 is refueled. The seal bearing 38 prevents the mixture of the refrigerant gas from the electric motor chamber 1b into the hydraulic chamber 39b. When the refrigerant gas is mixed in the hydraulic chamber 39b, the lubrication performance of the thrust sliding portion 39 is significantly reduced. An appropriate amount of oil supplied to the hydraulic chamber 39b flows into the back pressure chamber 41 via the inner seal ring 34a. The oil flowing into the back pressure chamber 41 mixes with the refrigerant gas in that portion,
It moves to the compression chamber 7 through the throttle hole 6e. The oil that has reached the compression chamber 7 is pressurized together with the refrigerant gas, and moves to the electric motor chamber 1b through the discharge chamber 1a below the fixed scroll 5 and the communication passage on the outer peripheral portion of the frame. The refrigerant gas and the oil are separated in the discharge chamber 1a and the electric motor chamber 1b, and the oil drops into the oil sump 22 at the lower part of the closed container 1 and is supplied again to the respective sliding parts.

In FIG. 2, the wrap curve of the fixed scroll 5 is an involute curve, and a wrap end portion 5n and a suction hole 16 into which a refrigerant gas enters are arranged. The suction chamber 5f has a semicircular annular shape, and the center of the inner wall surface 5p and the end plate 5a forming the arc-shaped suction chamber 5f is a point Of. The point Off below the center point Of is the center of the basic circle of the involute curve of the lap portion 5b, and is in an eccentric positional relationship with the point Of. The point Ofo is the center of the discharge hole 10 provided in the central portion 5a of the end plate on the fixed scroll 5 side and at a position slightly eccentric toward the wrap end portion. The discharge hole 10
The outer edge of is close to the inner curve of the wrap start 70. As shown in FIG. 3, the opening of the discharge hole 10 is tapered to further reduce the passage resistance at the discharge portion. In this way, the size of the discharge hole 10 is set to be approximately the same as the inner diameter of the orbiting bearing portion 31, so that the passage area of the discharge hole 10 is about several times to about ten times that of the conventional machine. Can be widely secured. Naturally, since there is no refraction passage in the conventional machine, the discharge pressure loss can be greatly reduced in combination with the effect of the enlarged structure of the discharge port. Further, there is an effect that the flow of the refrigerant gas in the discharging process by both scrolls becomes smooth and the over-compression loss becomes smaller.

In FIG. 4, the end plate 6 of the orbiting scroll 6 is shown.
The center of a is the point Om. Point Om below central point Om
m is the center of the basic circle of the involute curve of the lap portion 6b, and has a eccentric positional relationship with the point Om. The outer curved end of the wrap 6b, which is the outer edge 75 of the wrap winding end 6n of the orbiting scroll 6, is close to the outer end of the end plate 6a. With this structure, the outer dimension Dsi (see FIG. 5) of the orbiting scroll can be designed to be smaller.
The end plate 6a penetrates through the fine holes 6c and 6d along the side wall of the lap and guides an intermediate pressure between the suction pressure and the discharge pressure to the back pressure chamber 41 which is the back surface of the end plate 6a. In the present invention, the essential effect and action are not eliminated even without the pores 6c and 6d. In FIG. 5, gaps δm1 and δm2 are set inside the wrap tip end surface 6p and the end surface 6r of both ends of the slewing bearing portion 31. As shown in FIG. 1, this gap is made to have an atmosphere of high-pressure oil, and the high-pressure oil is guided to the radial groove 6g 'and the ring groove 6g, and between the scroll wraps at the center of the wrap tip surface 6p. It can be used for lubrication of the thrust sliding portion.

FIG. 6 is a partial cross-sectional view showing the flow of the refrigerant gas and the oil flowing laterally from the auxiliary frame 46. The refrigerant gas flowing out from the auxiliary frame 46 in the lateral direction passes through the oil separation element 44 provided around the auxiliary gas. The oil separation element 44 is assembled so as to be sandwiched by the horizontal plate 110 attached to the auxiliary frame 46 and the end plate portion 5a of the fixed scroll 5. The step surface 14g between the orbiting bearing portion 31 of the orbiting scroll member 6 and the extension axis shaft portion 14f engaging with the eccentric shaft portion 14a is located above the tooth bottom surface of the wrap portion 5b of the fixed scroll. Cage,
It has a gap δm2. On the other hand, a step surface 14k with the crankshaft 14 that engages with the eccentric shaft portion 14a of the slewing bearing portion 31
Has a gap δm3 from the end face of the orbiting scroll 6. By setting this gap, unnecessary sliding in the thrust direction can be avoided.

FIG. 7 is a vertical sectional view of a hermetic scroll compressor showing the entire structure of the present invention. In FIG. 7, the fixed scroll member 5 and the orbiting scroll member 6 which become the compressor unit 100 are engaged with each other to form a pair of compression chambers (closed spaces).
7 and 7a are formed. As shown in FIGS. 2 and 3, the fixed scroll member 5 is composed of a disk-shaped end plate 5a and a wrap 5b which stands upright on the end plate 5a and is formed in an involute curve or a curve similar thereto, and has a central portion. Outlet 1
0, the suction port 16 is provided in the outer peripheral portion. The orbiting scroll member 6 is, as shown in FIGS. 4 and 5, a disk-shaped end plate 6a.
A wrap 6b which is upright to this and which is formed in the same shape as the wrap of the fixed scroll, and a boss 6c which encloses the orbiting bearing portion 31 in the central portion of the end plate. The frame 11 has a main bearing portion 40 and a gas seal bearing portion 3 in the central portion.
8, the rotary shaft 14 is vertically supported by these bearings, and the rotary shaft penetrates inside the lap, so-called eccentric shaft.
14a is inserted into the boss 6c so as to be capable of turning motion. The fixed scroll member 5 is fixed to the frame 11 by a plurality of bolts (not shown), and the orbiting scroll member 6 is supported by the frame 11 by an Oldham mechanism 12 including an Oldham ring and an Oldham key, and the orbiting scroll member 6 is fixed. The scroll member 5 is formed so as to rotate without rotating. An upper portion of the rotating shaft 14 is directly connected to the electric motor unit 3. In addition, the compressor unit 100 is accommodated in the lower side of the closed container 2, and the electric motor unit 3 is accommodated in the upper side. And the closed container 2
The interior is divided by a frame 11 into a lower chamber 1a (discharge chamber) and an upper motor chamber 1b. A horizontal suction pipe 17 is connected to the suction port 16 of the fixed scroll member 5 so as to pass through the closed container 2. In the lower chamber 1a where the discharge port 10 is opened, a ring-shaped oil separation element 44 composed of a wire mesh demister for separating the oil in the refrigerant gas passing through the discharge passage 46a in the auxiliary frame 46 as shown in the figure. It is arranged. The refrigerant gas passing therethrough is guided to the upper electric motor chamber 1b via the fixed scroll member 5 and the rectangular passage 18 provided in the outer peripheral portion of the frame 11.
Further, the refrigerant gas in the upper electric motor chamber 1b is guided to the outside by the discharge pipe 20 penetrating the hermetically sealed container 2 through the space around the motor 3 and the upper chamber 1c. Incidentally, 63 is an oil level gauge.

FIG. 8 is a partial vertical sectional view of a hermetic scroll compressor according to another embodiment. An inner seal ring 34a is arranged in the thrust portion facing the frame 11 in the central portion on the rear surface of the end plate 6a of the orbiting scroll member 6. The outer region of the inner seal ring 34a is set to the atmosphere of suction pressure. Therefore, the end plate 6a of the orbiting scroll 6 is
No throttling holes 6d and 6e penetrating therethrough are provided. In order to stabilize the behavior of the end plate 6a of the orbiting scroll member 6, a high pressure region which is an inner region of the inner seal ring 34a is shown in FIG.
It is widely set for the embodiment of. Specifically, high-pressure oil is caused to act on the central portion on the rear surface of the end plate of the orbiting scroll member 6, and the high-pressure oil region on the rear surface of the end plate of the orbiting scroll member is
With respect to the outer dimension Dso of the orbiting scroll end plate, the outer dimension Dod of the inner seal ring portion 34a is approximately Dod /
The ratio is set to Dso = 0.7 (around) or more. It is characterized in that the high pressure oil region on the rear surface of the end plate of the orbiting scroll member is wide. Thrust sliding part 39
For lubrication, a plurality of ring grooves 11p are provided on the frame side. The Oldham ring of the rotation preventing member 12 and the key groove portion 12m are arranged outside the seal ring 34a. With this structure, the outer seal ring 34b set in FIG. 1 is not required, and the outer shape of the compressor can be downsized by that size. With the structure shown in FIG. 8, the oil supply passage 13 provided in the extension shaft center shaft portion 14f and the crankshaft 14 in the inner region of the inner seal means 34a set in a wide range.
The differential pressure oil supply utilizing the differential pressure between the discharge pressure and the suction pressure on the downstream side can be applied to these thrust peripheral portions 39 via the. With these oil supply structures, it is possible to secure a sufficient amount of oil to each sliding part, and conditions for a low operating pressure ratio, such as a low operating pressure ratio of about 1.1 at the ratio of discharge pressure and suction pressure. The operation of the air conditioner, which allows operation under a wide range of pressure ratios, is further improved.

[0012]

The present invention has the following effects.

(1) The sliding loss of the bearing portion can be reduced, and the behavior of the orbiting scroll is stabilized by the expansion structure of the discharge port and the structure in which the overturning moment does not act to reduce the loss of leakage inside the compression chamber. The performance of can be greatly improved.

(2) Sliding loss in the thrust direction between scroll wraps can be reduced.

With respect to (3), (1) and (2), the shaft structure of the compressor of the axial penetration type reduces the end plate displacement of the orbiting scroll and reduces the inclination of the orbiting scroll. Therefore, the degree of partial contact on the thrust sliding surface is reduced,
The surface pressure is also reduced, the lubricity of the sliding portion is improved, the abrasion of the sliding portion can be suppressed, and seizure can be prevented.

(4) It is possible to secure a sufficient amount of oil to each sliding portion, and to operate even under conditions of low operating pressure ratio, for example, conditions of low operating pressure ratio of about 1.1 of discharge pressure and suction pressure. It is possible to operate in a wide pressure ratio range.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a hermetic scroll compressor.

FIG. 2 is a plan view of a fixed scroll.

FIG. 3 is a sectional view of a fixed scroll.

FIG. 4 is a plan view of an orbiting scroll.

FIG. 5 is a sectional view of an orbiting scroll.

FIG. 6 is a partial sectional view of a hermetic scroll compressor according to another embodiment.

FIG. 7 is a sectional view of a hermetic scroll compressor showing the overall configuration of the present invention.

FIG. 8 is a partial cross-sectional view of a hermetic scroll compressor according to another embodiment.

[Explanation of symbols]

2 ... Airtight container, 5 ... Fixed scroll, 5a, 6a ... Scroll end plate part, 6 ... Orbiting scroll, 7 ... Compression chamber, 11
... Frame, 14 ... Crankshaft, 18 ... Communication passage, 22 ...
Oil sump, 31 ... Slewing bearing, 32 ... Extension shaft bearing, 33 ...
Thrust bearing, 38 ... Sealing means (bearing), 40 ... Main bearing.

Claims (1)

[Claims] 1. A fixed scroll member and an orbiting scroll member, which stand upright with a spiral wrap on a disk-shaped end plate, are engaged with each other with the wrap inside, and the orbiting scroll member is orbited relative to the fixed scroll member without rotating. Exercise,
The fixed scroll member is provided with a discharge hole opening in the center and a suction port opening in the outer peripheral portion, sucks gas through the suction port, and moves it around a compression space formed by the scroll members to increase the volume. An eccentricity of the crankshaft is provided in the center portion of the orbiting scroll member, the main bearing portion is provided in the center portion of the frame that reduces and compresses the gas and fixes the fixed scroll member. In a shaft-through scroll compressor in which the shaft portion is inserted to the wrap tip portion and the crankshaft further extends the eccentric shaft tip to the fixed scroll side, a discharge hole provided in the central portion of the fixed scroll side. The shaft center shaft part is extended inside, the bearing part supporting the extended shaft center shaft part is arranged on the side opposite to the wrap of the fixed scroll, and the thrust bearing part supporting the crankshaft is provided in front. Axis through the scroll compressor being characterized in that formed on the end of the extension axis shaft.