JP2015036527A - Compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compressor having a simple structure for reducing leakage loss to improve the efficiency.SOLUTION: The compressor includes a sealed container, a compression element arranged in the sealed container, and a motor arranged in the sealed container for driving the compression element via a shaft, the compression element including a first cylinder, a second cylinder, and a middle plate arranged between the first cylinder and the second cylinder. A center C of a through-hole 170a of the middle plate 170 exists in the direction of the bottom dead center of a piston 129 away from an axial center L of the shaft. This increases a seal width W to suppress the leakage of gas from a high pressure chamber to the side of a low pressure chamber.

Description

  The present invention relates to a compressor.

  Conventionally, some compressors include two cylinders and a middle plate disposed between the two cylinders. A piston fitted to the eccentric part of the shaft is disposed in each cylinder. The piston has a roller and a blade fixed to the outer peripheral surface of the roller.

  By the way, from the viewpoint of ensuring the reliability of the eccentric part of the shaft, if the diameter of the eccentric part (ensuring the minimum oil film thickness) is increased, the inner diameter of the through hole of the middle plate passing through the outer diameter of the eccentric part is growing. Thus, when the through hole of the middle plate becomes large, as shown in FIG. 6, the outer peripheral surface of the piston 101 and the through hole of the middle plate 102 in the seal portion formed by the overlap of the piston 101 and the middle plate 102 are provided. The seal distance (seal width) W between the inner peripheral surface of 102a is reduced. Then, the high-pressure (or intermediate-pressure) gas in the cylinder 103 leaks to the low-pressure side through the seal width W as shown by the arrow in FIG.

  In particular, the outer peripheral surface of the roller has a cut-out surface 101a adjacent to the base of the blade, and the point where the seal width W is minimized is the cut-out surface 101a of the roller. Leakage loss at the part increases.

  When R32 is used as the refrigerant, the temperature difference between the piston 101 and the cylinder 103 increases, so the CR gap (the difference in height between the piston 101 and the cylinder 103) H needs to be increased, but the leakage loss further increases. To do. In order to suppress this leakage loss, it is necessary to reduce the inner diameter of the through hole 102a of the middle plate 102. However, since the reliability of the eccentric part of the shaft is lowered, the inner diameter of the through hole 102a of the middle plate 102 is reduced. Can not.

  Therefore, there is a conventional compressor described in Japanese Patent Publication No. 54-121405 (Patent Document 1). In this compressor, the middle plate is divided at the center, and the divided middle plate is directly attached between the two eccentric portions without passing through the eccentric portion of the shaft. As a result, the inner diameter of the through hole of the middle plate is reduced to suppress the decrease in efficiency.

Japanese Patent Publication No.54-121405

  However, the above conventional compressor has a problem that the structure is complicated and the cost is high because the middle plate has a divided structure.

  Accordingly, an object of the present invention is to provide a compressor capable of improving efficiency by reducing leakage loss with a simple structure.

In order to solve the above problems, the compressor of the present invention is:
A sealed container;
A compression element disposed in the sealed container;
A motor disposed in the sealed container and driving the compression element via a shaft;
The compression element is
A first cylinder;
A second cylinder;
A middle plate disposed between the first cylinder and the second cylinder;
A first piston disposed within the first cylinder and fitted into a first eccentric portion of the shaft;
A second piston disposed in the second cylinder and fitted to a second eccentric portion of the shaft;
The first and second pistons are
Laura,
A blade fixed to the outer peripheral surface of the roller,
The outer peripheral surface of the roller includes a notched surface notched adjacent to the base of the blade,
The center of the through hole through which the shaft of the middle plate passes is shifted in the bottom dead center direction of the piston with respect to the shaft center of the shaft.

  Here, the shape of the cut-out surface is not an arc shape but is, for example, a linear shape. The bottom dead center refers to a state where the blade protrudes most into the cylinder, and refers to a state where the rotation angle of the piston is 180 °.

  According to the compressor of the present invention, the seal width between the notch surface of the roller and the inner peripheral surface of the through hole of the middle plate in the seal portion formed by the overlap margin of the roller and the middle plate is the shortest in the roller. However, since the center of the through hole of the middle plate is displaced in the direction of the bottom dead center of the piston with respect to the shaft center, this shortest seal width can be increased. Thereby, the leakage loss of high-pressure (or intermediate-pressure) gas can be reduced, and the efficiency can be improved. Further, when assembling the middle plate, the width of the seal can be easily increased simply by passing the middle plate through the eccentric part of the shaft and moving the middle plate in the direction of the bottom dead center.

  Moreover, in the compressor of one Embodiment, the hollow part which contact | connects the said base part of the said blade is provided in the said notch surface of the said roller of the said piston.

  According to the compressor of this embodiment, the notch surface of the roller of the piston is provided with a recess, and the seal width at the recess is the shortest in the roller. Since the center of the through hole in the middle plate is displaced in the direction of the bottom dead center of the piston with respect to the shaft center, this shortest seal width can be increased, reducing leakage loss and improving efficiency. It can be improved.

  Moreover, in the compressor of one Embodiment, the said bottom dead center direction is a direction from which the rotation angle of the said piston is 180 degrees or more and less than 270 degrees.

  According to the compressor of this embodiment, the bottom dead center direction is a direction in which the rotation angle of the piston is 180 ° or more and less than 270 °, so that the piston is at a position where the gas pressure is highest. However, the middle plate can be shifted in a direction to suppress this leakage loss.

  According to the compressor of the present invention, since the center of the through hole of the middle plate is shifted in the direction of the bottom dead center of the piston with respect to the shaft center of the shaft, the leakage loss is reduced with a simple structure. Efficiency can be improved.

It is sectional drawing which shows the compressor of 1st Embodiment of this invention. It is a top view by the side of the 1st cylinder of a compression element. It is an enlarged view of a 1st piston. It is sectional drawing by the side of the 1st cylinder of a compression element. It is an enlarged view of a piston while showing the compressor of a 2nd embodiment of the present invention. It is sectional drawing which shows the conventional compressor.

  Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1 is a longitudinal sectional view showing a compressor according to a first embodiment of the present invention. As shown in FIG. 1, the compressor includes a hermetic container 1, a compression element 2 disposed in the hermetic container 1, and a compressor element 2 disposed in the hermetic container 1 via a shaft 12. And a motor 3 to be driven.

  This compressor is a so-called vertical high-pressure dome-type rotary compressor, in which the compression element 2 is placed down and the motor 3 is placed up in the sealed container 1. The rotor 6 of the motor 3 drives the compression element 2 via the shaft 12.

  The compression element 2 sucks refrigerant gas through the suction pipes 111 and 211. The refrigerant gas is obtained by controlling a condenser, an expansion mechanism, and an evaporator (not shown) that constitute an air conditioner as an example of a refrigeration system together with the compressor. Carbon dioxide is used as the refrigerant, but refrigerants such as HC, HFC such as R410A, and HCFC such as R22 and R32 may be used.

  In the compressor, the high-temperature and high-pressure refrigerant gas compressed by the compression element 2 is discharged from the compression element 2 to fill the inside of the hermetic container 1 and through a gap between the stator 5 and the rotor 6 of the motor 3. After the motor 3 is cooled, it is discharged to the outside from a discharge pipe 13 provided on the upper side of the motor 3.

  The motor 3 includes a rotor 6 and a stator 5 disposed so as to surround the outer peripheral side of the rotor 6.

  The rotor 6 includes a cylindrical rotor core 610 and a plurality of magnets embedded in the rotor core 610. The rotor core 610 is made of, for example, laminated electromagnetic steel plates. The rotor core 610 is fixed to the shaft 12. The magnet is a flat permanent magnet. The plurality of magnets are arranged at equally spaced center angles in the circumferential direction of the rotor core 610.

  The stator 5 includes a cylindrical stator core 510 and a coil 520 wound around the stator core 510. The stator core 510 is composed of a plurality of laminated steel plates, and is fitted into the sealed container 1 by shrink fitting or the like. The coil 520 is wound around each tooth portion of the stator core 510, and the coil 520 is a so-called concentrated winding.

  The compression element 2 includes a front bearing 50, a rear bearing 60, a first cylinder 121, a middle plate 170 and a second cylinder 221 disposed between the front bearing 50 and the rear bearing 60, and a first cylinder 221. A piston 129 and a second piston 229 are provided.

  The first cylinder 121, the middle plate 170, and the second cylinder 221 are sequentially arranged along the shaft 12 from the front bearing 50 side to the rear bearing 60 side.

  The first cylinder 121 is sandwiched between the front bearing 50 and the middle plate 170. A first suction pipe 111 connected to an accumulator (not shown) communicates with the first cylinder chamber 122 of the first cylinder 121.

  The first piston 129 is fitted to the first eccentric portion 126 of the shaft 12 disposed in the first cylinder chamber 122. The first piston 129 is disposed in the first cylinder chamber 122 so as to be able to revolve, and eccentrically rotates in the first cylinder 121 to perform a compression action. The refrigerant gas compressed in the first cylinder chamber 122 is discharged to the outside of the first cylinder chamber 122 through the discharge hole 51 a of the front bearing 50.

  The second cylinder 221 is sandwiched between the middle plate 170 and the rear bearing 60. A second suction pipe 211 connected to an accumulator (not shown) communicates with the second cylinder chamber 222 of the second cylinder 221.

  The second piston 229 is fitted in the second eccentric portion 226 of the shaft 12 disposed in the second cylinder chamber 222. The second piston 229 is disposed in the second cylinder chamber 222 so as to be able to revolve, and eccentrically rotates in the second cylinder 221 to perform a compression action. The refrigerant gas compressed in the second cylinder chamber 222 is discharged to the outside of the second cylinder chamber 222 through a discharge hole (not shown).

  The first eccentric portion 126 and the second eccentric portion 226 are at a position shifted from the shaft 12 by 180 °. That is, the compression action of the first cylinder chamber 122 and the compression action of the second cylinder chamber 222 are in a phase shifted by 180 °.

  FIG. 2 is a plan view of the compression element 2 on the first cylinder 121 side. As shown in FIG. 2, the first piston 129 includes a roller 27 and a blade 28 fixed to the outer peripheral surface of the roller 27.

  The blade 28 partitions the first cylinder chamber 122. In the first cylinder chamber 122, a discharge hole 51a and a suction hole 121a through which the first suction pipe 11 communicates open.

  The blade 28 divides the first cylinder chamber 122 into a low pressure chamber (suction chamber) 122a that communicates with the suction hole 121a and a high pressure chamber (discharge chamber) 122b that communicates with the discharge hole 51a. That is, the chamber on the right side of the blade 28 forms a low pressure chamber 122a, and the chamber on the left side of the blade 28 forms a high pressure chamber 122b.

  Semi-cylindrical rocking bushes 25, 25 are in close contact with both surfaces of the blade 28 for sealing. Lubrication is performed between the blade 28 and the rocking bushes 25 and 25 with lubricating oil.

  The swing bushes 25, 25 are rotatably fitted in a bush fitting hole 121b formed in the first cylinder 121 so as to face the first cylinder chamber 122, and the blade 28 is sandwiched from both sides. Supports movement and retreat.

  Then, the first eccentric portion 126 rotates eccentrically with the shaft 12, and the roller 27 fitted on the first eccentric portion 126 moves the outer peripheral surface of the roller 27 inside the first cylinder chamber 122. Revolves in contact with the surface.

  As the roller 27 revolves in the first cylinder chamber 122, the blade 28 moves forward and backward while holding both side surfaces of the blade 28 by the swing bushes 25 and 25. Then, a low-pressure refrigerant gas is sucked into the low-pressure chamber 122a from the first suction pipe 111, compressed to a high pressure in the high-pressure chamber 122b, and then the high-pressure refrigerant gas is discharged from the discharge hole 51a. The refrigerant gas discharged from the discharge hole 51 a is discharged to the outside of the first cylinder chamber 122.

  Here, the positional relationship of the first piston 129 with respect to the first cylinder 121 (first cylinder chamber 122) will be defined. When the piston 129 is at the top dead center position, that is, when the blade 28 is at the most advanced position in the bush fitting hole 121b, the rotation angle of the piston 129 about the axis L of the shaft 12 is 0 °. To do. When the piston 129 revolves from the top dead center and is at the bottom dead center position, that is, when the blade 28 is at the most protruding position in the cylinder 121 from the bush fitting hole 121b, the axis L of the shaft 12 is The rotation angle of the piston 129 at the center is 180 °. The discharge hole 51a is open at a position close to 360 ° within the piston rotation angle 270 ° to 360 ° of the first cylinder chamber 122.

  FIG. 3 shows an enlarged view of the first piston 129. As shown in FIG. 3, the outer peripheral surface of the roller 27 includes a notch surface 27 a adjacent to the base portion 28 a of the blade 28. The cutout surface 27 a is formed by cutting out the arc-shaped outer peripheral surface of the roller 27. The notch surface 27a is located on the radially inner side of the virtual cylindrical surface A that overlaps the other surfaces of the outer peripheral surface of the roller 27 except the notch surface 27a. The shape of the cutout surface 27a is not an arc shape, but is, for example, a linear shape. Regarding the radial thickness of the roller 27, the thickness at the notch surface 27a is smaller than the thickness at other surfaces other than the notch surface 27a.

  As shown in FIGS. 2 and 4, the center C of the through hole 170 a through which the shaft 12 of the middle plate 170 passes is shifted in the direction of the bottom dead center of the first piston 129 with respect to the axis L of the shaft 12. ing. The bottom dead center direction is a direction in which the rotation angle of the first piston 129 is 180 ° or more and less than 270 °.

  Next, the assembly of the middle plate 170 will be described. The through hole 170 a of the middle plate 170 is passed through the second eccentric part 226 of the shaft 12, and the middle plate 170 is disposed between the first eccentric part 126 and the second eccentric part 226. Then, the first and second cylinders 121 and 221 and the middle plate 170 are assembled by shifting the center C of the through hole 170a of the middle plate 170 with respect to the axis L of the shaft 12 toward the bottom dead center of the piston. .

  As shown in FIG. 4, in the seal portion formed by the overlap margin between the roller 27 and the middle plate 170, the gap between the notch surface 27 a of the roller 27 and the inner peripheral surface of the through hole 170 a of the middle plate 170 is. The seal width W is the shortest in the roller 27, but the center C of the through hole 170 a of the middle plate 170 is shifted in the direction of the bottom dead center of the piston with respect to the axis L of the shaft 12. The seal width W can be increased. Thereby, it is possible to suppress the high-pressure (or intermediate-pressure) gas in the high-pressure chamber 122b from leaking to the low-pressure chamber 122a side through the seal width W as indicated by the phantom line arrow in FIG. Therefore, it is possible to reduce the leakage loss of high pressure (or intermediate pressure) gas and improve efficiency.

  On the other hand, in the conventional example, as shown in FIG. 6, the center C of the through hole 102a of the middle plate 102 is concentric with the shaft center L of the shaft. For this reason, the seal width W at the notch surface 101a of the roller becomes very small, and the leakage loss increases.

  Further, according to the compressor having the above-described configuration, when the middle plate 170 is assembled, the middle plate 170 is simply passed through the first eccentric portion 126 of the shaft 12 and the middle plate 170 is moved in the direction of the bottom dead center. In addition, the seal width W can be increased. Therefore, leakage loss can be reduced while the middle plate 170 has a simple structure, and cost and efficiency can be improved.

  Further, the bottom dead center direction is a direction in which the rotation angle of the first piston 129 is 180 ° or more and less than 270 °, so that the first piston 129 is at a position where the gas pressure is highest. However, the middle plate 170 can be shifted in a direction to suppress this leakage loss.

  2 to 4, the first piston 129 has been described, but the second piston 229 is the same as the first piston 129.

(Second Embodiment)
FIG. 5 is an enlarged view of a piston while showing a compressor according to a second embodiment of the present invention. This second embodiment is different from the first embodiment only in the configuration of the piston. Only this different configuration will be described below. In the second embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 5, a notch surface 27 a of the roller 27 of the first piston 129 </ b> A is provided with a recess portion 27 b that contacts the base portion 28 a of the blade 28. The recess 27b has an R-shaped curved surface. The recess 27b is formed by cutting the blade, and the tip of the blade is transferred. Here, if the cutting of the cutting tool is suppressed, a convex portion remains at the base portion 28a of the blade 28, and the blade 28 may be bitten during operation.

  When the depth of the recess 27b is 0.2 to 0.5 mm, the distance between the center C of the through hole 170a of the middle plate 170 and the axis L of the shaft 12 is, for example, 0.1 to It is about 0.25 mm.

  In the second embodiment, the notched surface 27 a of the roller 27 is provided with a recessed portion 27 b, and the seal width W at the recessed portion 27 b is the shortest in the roller 27. Since the center C of the through hole 170a of the middle plate 170 is displaced in the direction of the bottom dead center of the piston with respect to the axis L of the shaft 12, the shortest seal width W can be increased, and leakage loss is reduced. To reduce the efficiency.

  In addition, this invention is not limited to the above-mentioned embodiment. For example, the feature points of the first and second embodiments may be variously combined.

  In the above embodiment, the bottom dead center direction is the direction in which the rotation angle of the piston is 180 ° or more and less than 270 °, but the direction in which the rotation angle of the piston exceeds 90 ° and less than 270 ° is also possible. Good.

  In the above-described embodiment, the first piston has been described, but the second piston has the same configuration and the same operational effects.

DESCRIPTION OF SYMBOLS 1 Airtight container 2 Compression element 3 Motor 12 Shaft 27 Roller 27a Notch surface 27b Recessed part 28 Blade 28a Base part 121 1st cylinder 122 1st cylinder chamber 126 1st eccentric part 129,129A 1st piston 170 Middle plate 170a Through hole 221 Second cylinder 222 Second cylinder chamber 226 Second eccentric part 229 Second piston C center L shaft center W seal width

Claims (3)

A sealed container (1);
A compression element (2) disposed in the sealed container (1);
A motor (3) disposed in the sealed container (1) and driving the compression element (2) via a shaft (12);
The compression element (2)
A first cylinder (121);
A second cylinder (221);
A middle plate (170) disposed between the first cylinder (121) and the second cylinder (221);
A first piston (129, 129A) disposed in the first cylinder (121) and fitted to a first eccentric part (126) of the shaft (12);
A second piston (229) disposed in the second cylinder (221) and fitted to a second eccentric part (226) of the shaft (12);
The first and second pistons (129, 129A, 229) are
Roller (27);
A blade (28) fixed to the outer peripheral surface of the roller (27);
The outer peripheral surface of the roller (27) includes a notched surface (27a) that is adjacent to the base (28a) of the blade (28),
The center (C) of the through hole (170a) through which the shaft (12) of the middle plate (170) passes is centered on the axis (L) of the shaft (12) with respect to the piston (129, 129A, 229). ) A compressor characterized by being displaced toward the bottom dead center. The compressor according to claim 1,
The notched surface (27a) of the roller (27) of the piston (129A) is provided with a recess (27b) in contact with the root (28a) of the blade (28). Compressor. The compressor according to claim 1 or 2,
The compressor is characterized in that the bottom dead center direction is a direction in which the rotation angle of the piston (129, 129A, 229) is 180 ° or more and less than 270 °.

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