JP2021124014A - Scroll compressor including frame holding bearing - Google Patents

Abstract

To maintain the amount of lubrication oil stored in a scroll compressor.SOLUTION: A scroll compressor 10 includes a motor 20, a frame 60 and an oil return passage P. A rotor 22 of the motor 20 rotates in the rotating direction R. The oil return passage P guides lubrication oil from the upper side to the lower side of the motor 20. The frame 60 includes a first fixed leg 61 and a second fixed leg 62. The first fixed leg 61 includes a first upstream surface 61b located on the upstream side in the rotating direction R. The second fixed leg 62 includes a second upstream surface 62b located on the upstream side in the rotating direction R. The first fixed leg 61, the oil return passage P and the second fixed leg 62 are disposed from the upstream side to the downstream side in the rotating direction R in this order. The movement of a refrigerant caused by the rotation of the rotor 22 generates a swirl flow. Resistance of the second upstream surface 62b to the swirl flow is larger than that of the first upstream surface 61b to the swirl flow.SELECTED DRAWING: Figure 5

Description

A scroll compressor with a frame that holds the bearings.

The scroll compressor disclosed in Patent Document 1 (Japanese Unexamined Patent Publication No. 2015-105637) has a lower bearing member. The lower bearing member rotatably supports the drive shaft. The lower bearing member has three legs. The three legs are fixed to the inner surface of the casing. An oil sump for storing lubricating oil is provided below the lower bearing member.

A compression mechanism is arranged above the lower bearing member. Lubricating oil is supplied to the compression mechanism to lubricate the compression mechanism. After leaving the compression mechanism, the lubricating oil is guided by the oil return guide and drops into the oil sump.

The refrigerant discharged from the compression mechanism contains lubricating oil. The refrigerant then moves to the vicinity of the lower bearing member. The refrigerant then receives force from the rotating rotor and swirls in the circumferential direction of the casing. In the process of swirling the refrigerant, the lubricating oil is separated from the refrigerant by cyclone separation.

In order to promote cyclone separation, it is better for the refrigerant to swirl. However, the swirling refrigerant flow can also act to prevent the lubricating oil from falling from the oil return guide into the oil sump. Therefore, the lubricating oil is mixed with the gas-state refrigerant. As a result, a phenomenon called "oil rising" in which the refrigerant is discharged to the outside of the scroll compressor while containing the lubricating oil occurs more violently. As a result, the amount of lubricating oil stored in the oil sump may be insufficient.

The scroll compressor of the first aspect includes a casing, a scroll compression mechanism, a motor, a crankshaft, a bearing, a frame, an oil separating member, and an oil return passage. The scroll compression mechanism is arranged inside the casing. The motor is located inside the casing and below the scroll compression mechanism. The motor has a stator and a rotor. The rotor rotates in the direction of rotation. The crankshaft connects the scroll compression mechanism to the motor. Bearings are located below the motor. The bearing rotatably supports the crankshaft. The frame is fixed to the casing. The frame supports the bearing. The oil separating member is fixed to the frame. The oil separating member suppresses mixing of the refrigerant and the lubricating oil inside the casing. The oil return passage guides the lubricating oil from above the motor to below the motor. The frame has a first fixed leg and a second fixed leg that are fixed to the casing. The first fixed leg has a first upstream surface located on the upstream side in the direction of rotation. The second fixed leg has a second upstream surface located on the upstream side in the direction of rotation. The first fixed leg, the oil return passage, and the second fixed leg are arranged in this order from the upstream side to the downstream side in the rotation direction. A swirling flow is generated by the rotation of the rotor moving the refrigerant inside the casing. The resistance of the second upstream surface to the swirling flow is greater than the resistance of the first upstream surface to the swirling flow.

According to this configuration, the resistance of the second upstream surface, which is easily hit by the lubricating oil, is larger than the resistance of the first upstream surface, which is hard to be hit by the lubricating oil. Therefore, since the lubricating oil is captured by the second upstream surface, the lubricating oil is difficult to diffuse.

The scroll compressor of the second aspect is the scroll compressor of the first aspect, and the first upstream surface has a first plane portion. The second upstream surface has a second flat surface portion. The area of the second flat surface portion is larger than the area of the first flat surface portion.

According to this configuration, the second upstream surface exhibits a large resistance by having a second plane portion having a large area.

The scroll compressor of the third aspect is the scroll compressor of the first aspect or the second aspect, and the first chamfering portion is provided on the side of the first upstream surface. A second chamfered portion is provided on the side of the second upstream surface. The radius of curvature of the second chamfered portion is smaller than the radius of curvature of the first chamfered portion.

According to this configuration, the second fixed leg exhibits a large resistance by having the second chamfered portion having a small radius of curvature.

The scroll compressor of the fourth aspect is any one of the scroll compressors of the first aspect to the third aspect, and the surface roughness of the first upstream surface and the surface roughness of the second upstream surface are different.

According to this configuration, the difference in resistance between the first upstream surface and the second upstream surface is brought about by the difference in their surface roughness.

The scroll compressor of the fifth aspect is the scroll compressor of the fourth aspect, and the surface roughness of the second upstream surface is coarser than the surface roughness of the first upstream surface.

According to this configuration, the second upstream surface exhibits a large resistance due to having a rough surface roughness.

The scroll compressor of the sixth aspect is any one of the scroll compressors of the first aspect to the fifth aspect, and the stator has a core cut located on the outer periphery of the stator. The oil return passage includes a core cut.

According to this configuration, the oil return passage includes a core cut. Therefore, at the height of the motor, a dedicated member constituting the oil return passage is not required.

It is sectional drawing of the scroll compressor 10 which concerns on a basic embodiment. It is a side view of a part part of a scroll compressor 10. It is a side view of a part part of a scroll compressor 10. It is a perspective view of the lower frame 60 and the oil separating member 70. It is a top view of the lower frame 60 and the oil separating member 70. It is a perspective view of the lower frame 60 and the oil separating member 70.

<Basic embodiment>
(1) Overall Configuration FIG. 1 is a cross-sectional view of the scroll compressor 10 according to the basic embodiment. The scroll compressor 10 is for producing a high-pressure refrigerant by compressing a low-pressure refrigerant which is a fluid. The scroll compressor 10 includes a casing 11, a motor 20, a crankshaft 30, a scroll compression mechanism 40, an upper frame 50, a lower frame 60, an oil separating member 70, an oil guide 51 (FIG. 2), and a refrigerant guide 52 (FIG. 3). Has.

(2) Detailed configuration (2-1) Casing 11
As shown in FIG. 1, the casing 11 houses various parts of the scroll compressor 10. The casing 11 has a body portion 11a, an upper portion 11b, and a lower portion 11c. The body portion 11a has a substantially cylindrical shape. The upper portion 11b and the lower portion 11c are airtightly joined to the body portion 11a. A suction pipe 15 is provided on the upper portion 11b. A discharge pipe 16 is provided on the body portion 11a. An oil sump 12 for storing lubricating oil is provided in the vicinity of the lower portion 11c.

(2-2) Motor 20
The motor 20 generates power for driving the scroll compression mechanism 40. The motor 20 is arranged inside the casing 11. The motor 20 is arranged below the scroll compression mechanism 40. The motor 20 has a stator 21 and a rotor 22.

The stator 21 has windings (not shown). The winding converts the electric power received by the scroll compressor 10 into a magnetic force. The stator 21 has a substantially cylindrical shape. The stator 21 is fixed to the body portion 11a. A notch called a core cut 21a is provided on the outer circumference of the stator 21. The gap between the body portion 11a and the stator 21 formed by the core cut 21a functions as a passage for the refrigerant.

The rotor 22 is provided in the vicinity of the stator 21. The rotor 22 has a permanent magnet (not shown). The rotor 22 has a substantially cylindrical shape. The rotor 22 rotates due to the interaction between the winding of the stator 21 and the permanent magnets of the rotor 22.

(2-3) Crankshaft 30
The crankshaft 30 transmits the power generated by the motor 20 to the scroll compression mechanism 40. The crankshaft 30 connects the scroll compression mechanism 40 and the motor 20. The crankshaft 30 is fixed to the rotor 22. The crankshaft 30 has a concentric portion 31 and an eccentric portion 32. The concentric portion 31 is concentric with the rotation shafts of the rotor 22 and the crankshaft 30. The eccentric portion 32 is eccentric from the rotation axis. The concentric portion 31 is rotatably supported by the upper bearing 35 and the lower bearing 36. The eccentric portion 32 is rotatably supported by an eccentric bearing 37. The upper bearing 35 is arranged above the motor 20. The lower bearing 36 is arranged below the motor 20. The eccentric bearing 37 is arranged in the vicinity of the scroll compression mechanism 40.

An oil rise hole 33 is provided inside the crankshaft 30. As the crankshaft 30 rotates, the lubricating oil in the oil sump 12 is sucked up into the oil rise hole 33, and then supplied to the scroll compression mechanism 40, the upper bearing 35, the lower bearing 36, and the eccentric bearing 37.

(2-4) Scroll compression mechanism 40
The scroll compression mechanism 40 is arranged inside the casing 11. The scroll compression mechanism 40 has a fixed scroll 41 and a movable scroll 42.

The fixed scroll 41 has a fixed plate portion 41a and a fixed wrap portion 41b. The fixing plate portion 41a is a portion that spreads in the horizontal direction. The fixed wrap portion 41b extends in the vertical direction from the fixing plate portion 41a. The fixed wrap portion 41b has a spiral shape in a plan view. A discharge hole 45 for discharging the high-pressure refrigerant is formed in the center of the fixed plate portion 41a.

The movable scroll 42 has a movable plate portion 42a, a movable wrap portion 42b, and a movable protruding portion 42c. The movable plate portion 42a is a portion that spreads in the horizontal direction. The movable wrap portion 42b extends in the vertical direction from the movable plate portion 42a. The movable wrap portion 42b has a spiral shape in a plan view. The movable protrusion 42c extends in the vertical direction from the movable plate portion 42a. The movable protrusion 42c has a recess. The recess accommodates the eccentric bearing 37 and the eccentric portion 32. The movable scroll 42 can revolve with respect to the fixed scroll 41.

Both the fixed scroll 41 and the movable scroll 42 define a plurality of compression chambers 43. The outermost compression chamber 43 communicates with the suction pipe 15.

(2-5) Upper frame 50
The upper frame 50 supports the upper bearing 35. The upper frame 50 supports the crankshaft 30 via the upper bearing 35. The upper frame 50 is fixed to the body portion 11a of the casing 11. The fixed scroll 41 is fixed to the upper frame 50. The upper frame 50 is formed with a refrigerant passage 50a that penetrates the upper frame 50 in the vertical direction.

(2-6) Lower frame 60
The lower frame 60 supports the lower bearing 36. The lower frame 60 supports the crankshaft 30 via the lower bearing 36. The lower frame 60 is fixed to the body portion 11a of the casing 11.

(2-7) Oil separating member 70
The oil separating member 70 suppresses mixing of the refrigerant and the lubricating oil. That is, the oil separation member 70 suppresses the scattering of the lubricating oil that may occur when the gas refrigerant hits the oil sump 12, and thus suppresses the mixing of the refrigerant and the lubricating oil. The oil separating member 70 is fixed to the lower frame 60.

(2-8) Oil guide 51
FIG. 2 is a side view of some parts of the scroll compressor 10. The oil guide 51 is provided on the body portion 11a of the casing 11. The oil guide 51 is provided with a groove 51a. The groove 51a guides the lubricating oil located above to the bottom. The groove 51a of the oil guide 51 and the core cut 21a of the stator 21 form an oil return passage P. The oil return passage P guides the lubricating oil from above the motor 20 to below the motor 20. The lubricating oil located above the oil guide 51 passes through the oil return passage P, and then falls to the oil return passage portion 79 of the oil separation member 70. The oil return passage portion 79 is located directly below the oil return passage P.

(2-9) Refrigerant guide 52
FIG. 3 is a side view of some parts of the scroll compressor 10. The refrigerant guide 52 is provided on the body portion 11a of the casing 11. The refrigerant guide 52 guides the refrigerant located above in the circumferential direction and downward. As a result, a part of the refrigerant travels horizontally and swirls along the inner peripheral surface of the body portion 11a. Further, the other part of the refrigerant travels downward and passes through the core cut 21a.

(3) Movement of refrigerant and lubricating oil The movement of refrigerant and lubricating oil will be described below. However, it should be noted that the refrigerant and lubricant do not move completely independently of each other. Refrigerant and lubricating oil are compatible. Therefore, the movement of the refrigerant or lubricating oil discussed below can also be the movement of a mixture of refrigerant and lubricating oil.

(3-1) Refrigerant The low-pressure refrigerant enters the inside of the scroll compressor 10 from the suction pipe 15 shown in FIG. The low-pressure refrigerant then enters the outermost compression chamber 43 of the scroll compression mechanism 40. The rotation of the crankshaft 30 revolves around the movable scroll 42, so that the compression chamber 43 moves to the center of the scroll compression mechanism 40 while reducing its volume. In this process, the low pressure refrigerant is compressed into a high pressure refrigerant. The high-pressure refrigerant exits from the discharge hole 45 to the upper space S1. After that, the high-pressure refrigerant reaches the central space S2 by passing through the refrigerant passage 50a of the upper frame 50. The high pressure refrigerant then reaches the refrigerant guide 52.

The refrigerant guide 52 causes a part of the refrigerant to rotate along the inner circumference of the body portion 11a while traveling horizontally. This swirling flow may be further accelerated by the rotation of the rotor 22. The other part of the refrigerant travels downward, passes through the core cut 21a, and collides with the oil separating member 70. Next, in the lower space S3 between the motor 20 and the lower frame 60, the rotation of the rotor 22 swirls the refrigerant.

(3-2) Lubricating oil Lubricating oil is sucked up from the oil sump 12 into the oil rising hole 33. After that, the lubricating oil is supplied to the scroll compression mechanism 40, the upper bearing 35, the lower bearing 36, and the eccentric bearing 37. After that, the lubricating oil exits the scroll compression mechanism 40, the upper bearing 35, the lower bearing 36, and the eccentric bearing 37. Next, the lubricating oil moves downward along the inner peripheral surface of the body portion 11a or the oil return passage P of the oil guide 51. The lubricating oil that has exited the oil return passage P passes through the core cut 21a and falls to the oil return passage portion 79 of the oil separation member 70.

(4) Detailed Structure of Lower Frame 60 and Oil Separating Member 70 FIG. 4 is a perspective view of the lower frame 60 and the oil separating member 70. The arrow in the figure indicates the rotation direction R of the rotor 22.

The lower frame 60 has a first fixed leg 61, a second fixed leg 62, and a third fixed leg 63. The first fixed leg 61, the second fixed leg 62, and the third fixed leg 63 are all fixed to the body portion 11a of the casing 11. The fixing method is, for example, welding.

The oil separating member 70 is a plate-shaped member fixed to the lower frame 60. The oil separating member 70 has a first portion 71, a second portion 74, and a third portion 77. The first part 71, the first fixed leg 61, the third part 77, the third fixed leg 63, the second part 74, and the second fixed leg 62 are arranged in this order from the upstream side to the downstream side in the rotation direction R. .. A notch 76 is formed in the second portion 74. The notch 76 is for dropping the lubricating oil collected on the oil separating member 70 into the oil sump 12.

FIG. 5 is a top view of the lower frame 60 and the oil separating member 70. An oil guide 51 is provided above the second portion 74 of the oil separating member 70. The first fixed leg 61 has a first upstream surface 61b located on the upstream side in the rotation direction R. The second fixed leg 62 has a second upstream surface 62b located on the upstream side in the rotation direction R. The third fixed leg 63 has a third upstream surface 63b located on the upstream side in the rotation direction R. The resistance of the second upstream surface 62b to the swirling flow is greater than the resistance of the first upstream surface 61b to the swirling flow. The resistance of the second upstream surface 62b to the swirling flow is greater than the resistance of the third upstream surface 63b to the swirling flow.

(5) How to increase the resistance of the second upstream surface 62b The following is an example of how to increase the resistance of the second upstream surface 62b. The following multiple methods may be combined.

As shown in FIG. 6, the second upstream surface 62b of the second fixed leg 62 has a second flat surface portion 62c. The first upstream surface 61b of the first fixed leg 61 has a first flat surface portion 61c. The first flat surface portion 61c and the second flat surface portion 62c are planar. A second chamfered portion 62d is provided on the side of the second upstream surface 62b. A first chamfered portion 61d is provided on the side of the first upstream surface 61b.

(5-1) Area of flat surface portion By setting the area of the second flat surface portion 62c to be larger than the area of the first flat surface portion 61c, the resistance of the second upstream surface 62b is set to be larger than the resistance of the first upstream surface 61b. Can also be increased.

(5-2) Chamfering By setting the radius of curvature of the second chamfered portion 62d to be smaller than the radius of curvature of the first chamfered portion 61d, the resistance of the second upstream surface 62b is set to be smaller than the resistance of the first upstream surface 61b. You can make it bigger.

(5-3) Surface Roughness By setting the surface roughness of the second upstream surface 62b to be coarser than the surface roughness of the first upstream surface 61b, the resistance of the second upstream surface 62b is set to the resistance of the first upstream surface 61b. Can be larger than.

(6) Features (6-1)
The resistance of the second upstream surface 62b, which is easily hit by the lubricating oil, is larger than the resistance of the first upstream surface 61b, which is hard to be hit by the lubricating oil. Therefore, since the lubricating oil is captured by the second upstream surface 62b, the lubricating oil is difficult to diffuse. The lubricating oil trapped in the second upstream surface 62b can fall from the notch 76 into the oil sump 12.

(6-2)
The second upstream surface 62b exhibits a large resistance by having the second flat surface portion 62c having a large area. This makes it easier for the lubricating oil to return to the oil sump 12.

(6-3)
The second fixed leg 62 exerts a large resistance by having the second chamfered portion 62d having a small radius of curvature. This makes it easier for the lubricating oil to return to the oil sump 12.

(6-4)
The difference in resistance between the first upstream surface 61b and the second upstream surface 62b is brought about by the difference in their surface roughness. The second upstream surface 62b exhibits a large resistance due to having a rough surface roughness. This makes it easier for the lubricating oil to return to the oil sump 12.

(6-5)
The oil return passage P includes a core cut 21a. Therefore, at the height of the motor 20, a dedicated member constituting the oil return passage P is not required.

(7) Modification Example In the basic embodiment, the number of fixed legs of the lower frame 60 is three. Instead, the number of fixed legs of the lower frame 60 may be a number other than 3, such as 2, 4, 5, or 6.

<Conclusion>
Although the embodiments of the present disclosure have been described above, it will be understood that various modifications of the forms and details are possible without departing from the purpose and scope of the present disclosure described in the claims. ..

10: Scroll compressor 11: Casing 12: Oil pool 20: Motor 21: Stator 21a: Core cut 22: Rotor 30: Crankshaft 35: Upper bearing 36: Lower bearing (bearing)
37: Eccentric bearing 40: Scroll compression mechanism 50: Upper frame 51: Oil guide 52: Refrigerant guide 60: Lower frame (frame)
61: First fixed leg 61b: First upstream surface 61c: First flat surface portion 61d: First chamfered portion 62: Second fixed leg 62b: Second upstream surface 62c: Second flat surface portion 62d: Second chamfered portion 63: Third fixed leg 63b: Third upstream surface 70: Oil separation member 71: First part 74: Second part 76: Notch 77: Third part 79: Oil return passage part P: Oil return passage R: Direction of rotation

Japanese Unexamined Patent Publication No. 2015-105637

Claims (6)

Casing (11) and
A scroll compression mechanism (40) arranged inside the casing and
A motor (20) that is arranged inside the casing and below the scroll compression mechanism and has a stator (21) and a rotor (22) that rotates in the rotation direction (R).
A crankshaft (30) connecting the scroll compression mechanism and the motor,
A bearing (36) that is arranged below the motor and rotatably supports the crankshaft.
A frame (60) fixed to the casing and supporting the bearing,
An oil separating member (70) fixed to the frame and suppressing mixing of the refrigerant and the lubricating oil inside the casing,
An oil return passage (P) for guiding the lubricating oil from above the motor to below the motor,
With
The frame has a first fixed leg (61) and a second fixed leg (62) that are fixed to the casing.
The first fixed leg has a first upstream surface (61b) located on the upstream side in the rotation direction.
The second fixed leg has a second upstream surface (62b) located on the upstream side in the direction of rotation.
The first fixed leg, the oil return passage, and the second fixed leg are arranged in this order from the upstream side to the downstream side in the rotation direction.
The rotation of the rotor moves the refrigerant inside the casing, so that a swirling flow is generated.
The resistance of the second upstream surface to the swirling flow is greater than the resistance of the first upstream surface to the swirling flow.
Scroll compressor (10). The first upstream surface has a first flat surface portion (61c).
The second upstream surface has a second flat surface portion (62c).
The area of the second flat surface portion is larger than the area of the first flat surface portion.
The scroll compressor according to claim 1. A first chamfered portion (61d) is provided on the side of the first upstream surface.
A second chamfered portion (62d) is provided on the side of the second upstream surface.
The radius of curvature of the second chamfered portion is smaller than the radius of curvature of the first chamfered portion.
The scroll compressor according to claim 1 or 2. The surface roughness of the first upstream surface and the surface roughness of the second upstream surface are different.
The scroll compressor according to any one of claims 1 to 3. The surface roughness of the second upstream surface is coarser than the surface roughness of the first upstream surface.
The scroll compressor according to claim 4. The stator has a core cut (21a) located on the outer circumference of the stator.
The oil return passage includes the core cut.
The scroll compressor according to any one of claims 1 to 5.

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