JP2009203963A - Scroll compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a scroll compressor capable of accurately turning a rotation regulating pin of a movable scroll member along an inner peripheral surface of a circular hole, even if the movable scroll member is formed of an aluminum-based raw material. <P>SOLUTION: Since a plurality of pins 22b arranged in the movable scroll member and a plurality of circular holes 23a arranged in a support member 23 are formed so that a pitch circle radius R1 of the respective pins 22b becomes smaller than a pitch circle radius R2 of each circular hole 23a and a difference between the pitch circle radius R1 of the respective pins 22b and the pitch circle radius R2 of each circular hole 23a becomes 0.05%-0.15% of the pitch circle radius R2 of each circular hole 23a, even if the movable scroll member is formed of the aluminum-based raw material having a thermal expansion coefficient larger than that of an iron-based raw material, a dimensional difference of the respective pitch circle radiuses R1 and R2 by a difference in the thermal expansion in operation can be absorbed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a scroll type compressor used in a refrigerant circuit of various types of cooling equipment, for example.

  Conventionally, this type of scroll compressor includes a drive shaft having an eccentric shaft eccentric to a rotation shaft at one end, a motor for rotating the drive shaft, a fixed scroll member having a spiral body at one end surface, A movable scroll member having a spiral body facing the spiral body of the fixed scroll member on the end surface and revolving with respect to the fixed scroll member around the rotation shaft of the drive shaft by the eccentric rotation of the eccentric shaft of the drive shaft is movable. The pins projecting from the circumferential direction on the other end surface of the scroll member are engaged with the circular holes provided in the circumferential direction of the member on the compressor main body side, and each pin is rounded as the movable scroll member revolves. There is known one that regulates the rotation of the movable scroll member by turning along the inner peripheral surface of the hole (see, for example, Patent Document 1).

In this compressor, in order to restrict the rotation of the movable scroll member, each pin needs to be accurately swung along the inner peripheral surface of each circular hole. For this purpose, the pitch circle radius of each pin and each pin Ideally, the pitch circle radius of the circular hole should match.
JP 2007-239539 A

  By the way, although the components of the compressor are mainly formed of an iron-based material, the iron-based material is heavy, and thus there is a problem that the load of the motor that drives the movable scroll member is increased. Therefore, if the movable scroll member is formed of an aluminum-based material, the load on the motor can be reduced by reducing the weight of the movable scroll member. However, since the member provided with each circular hole also serves as a member that supports the drive shaft and the movable scroll member, it needs to be formed of an iron-based material to ensure sufficient strength. For this reason, when the movable scroll member provided with each pin is formed of an aluminum-based material, the coefficient of thermal expansion of the movable scroll member is larger than that of the member provided with each circular hole. There is a problem in that a dimensional difference due to thermal expansion during operation occurs between the pitch circle radius of the holes and each pin cannot be swung accurately along the inner peripheral surface of each circular hole.

  The present invention has been made in view of the above problems, and the object of the present invention is to provide a movable scroll member even if the movable scroll member is formed of a member having a larger coefficient of thermal expansion than a member provided with each circular hole. An object of the present invention is to provide a scroll type compressor capable of accurately rotating a rotation regulating pin along the inner peripheral surface of a circular hole.

  In order to achieve the above object, the present invention provides a drive shaft having an eccentric shaft that is eccentric with respect to a rotating shaft at one end, a fixed scroll member having a spiral body at one end surface, and a spiral body of the fixed scroll member at one end surface. A movable scroll member having an opposing spiral body and revolving with respect to the fixed scroll member around the rotation axis of the drive shaft by eccentric rotation of the eccentric shaft of the drive shaft, and a plurality of circumferential directions on the other end surface of the movable scroll member Pins projecting at the locations are engaged with circular holes provided at a plurality of locations in the circumferential direction of the member on the compressor body side, and each pin is turned along the inner peripheral surface of each circular hole as the movable scroll member revolves. In the scroll type compressor that restricts the rotation of the movable scroll member, the movable scroll member has a coefficient of thermal expansion larger than that of the member provided with each circular hole. Formed by wood, each pin and each circular hole, the pitch circle radius of each pin is formed to be smaller than the pitch circle radius of each circular hole.

  Thereby, for example, a movable scroll member can be reduced in weight by forming a movable scroll member with an aluminum-type material, and forming a member provided with each circular hole with an iron-type material. In this case, the aluminum-based material has a larger coefficient of thermal expansion than the iron-based material, but each pin and each circular hole are formed so that the pitch circle radius of each pin is smaller than the pitch circle radius of each circular hole. Therefore, the dimensional difference of each pitch circle radius due to the difference in thermal expansion during operation is absorbed.

  According to the present invention, for example, the movable scroll member can be reduced in weight by forming the movable scroll member from an aluminum-based material and forming the member provided with each circular hole from an iron-based material. It is possible to reduce the load for driving the motor. In this case, although the aluminum-based material has a larger coefficient of thermal expansion than the iron-based material, it can absorb the dimensional difference between the pitch circle radii due to the difference in thermal expansion during operation. The pin can be accurately swung along the inner peripheral surface of the circular hole, and the decrease in volumetric efficiency and adiabatic compression efficiency due to the rotation of the movable scroll member can be effectively suppressed.

  1 to 4 show an embodiment of the present invention. FIG. 1 is a side sectional view of a scroll compressor, FIG. 2 is a plan view showing pins and circular holes, and FIG. 3 is a graph showing volume efficiency and pitch circle radius. FIG. 4 is a diagram showing the relationship between the dimensional difference and FIG. 4 is a diagram showing the relationship between the adiabatic compression efficiency and the dimensional difference of the pitch circle radius.

  The scroll compressor shown in FIG. 1 includes a compressor body 10 having an upper end and a lower end closed, a compression mechanism 20 that compresses refrigerant, a drive shaft 30 that drives the compression mechanism 20, and a motor 40 that rotates the drive shaft 30. And has.

  The compressor body 10 includes a cylindrical housing 11 having upper and lower ends opened, an upper lid 12 that closes the upper end opening of the housing 11, and a lower lid 13 that closes the lower end opening of the housing 11. A refrigerant suction pipe 14 is attached so as to penetrate through the side surface, and a refrigerant discharge pipe 15 is attached to the upper lid 12 so as to penetrate therethrough.

  The compression mechanism 20 includes a fixed scroll member 21 and a movable scroll member 22 facing each other, and the movable scroll member 22 is supported by a support member 23. The fixed scroll member 21 has one spiral body 21a on one end surface (lower surface), and a refrigerant discharge hole 21b is provided at the center in the radial direction. The movable scroll member 22 is formed of an aluminum-based material, and the other spiral body 22a is provided on one end face (upper surface) so as to be engaged with the spiral body 21a of the fixed scroll member 21. A plurality of pins 22 b for restricting the rotation of the movable scroll member 22 are provided on the other end surface (lower surface) of the movable scroll member 22, and the pins 22 b are spaced from each other in the circumferential direction of the movable scroll member 22. Is arranged. The support member 23 is formed of an iron-based material and is fixed to the inner peripheral surface of the housing 11. A plurality of circular holes 23 a for restricting the rotation of the movable scroll member 22 are provided on the upper surface of the support member 23, and the circular holes 23 a are arranged at intervals in the circumferential direction of the support member 23. Each pin 22b is engaged with each circular hole 23a, and each pin 22b rotates along the inner peripheral surface of the circular hole 23a as the movable scroll member 22 revolves. In this case, each pin 22b and each circular hole 23a has a pitch circle radius R1 (radius of a circle C1 passing through the center of each pin 22b) of each pin 22b and a pitch circle radius R2 of each circular hole 23a (of each circular hole 23a). The difference between the pitch circle radius R1 of each pin 22b and the pitch circle radius R2 of each circular hole 23a is not less than 0.05% of the pitch circle radius R2 of each circular hole 23a. .15% or less. That is, each pin 22b and each circular hole 23a has a difference between the pitch circle radius R1 of each pin 22b and the pitch circle radius R2 of each circular hole 23a as shown in the following formula (1). A value D obtained by dividing by the radius of circle R2 and multiplying by 100 is 0.05% or more and 0.15% or less.

D = (R2-R1) × 100 / R2 (1)
An upper end side of the drive shaft 30 is rotatably supported by the support member 23, and a lower end of the drive shaft 30 is rotatably supported by a bearing 31 fixed to the inner peripheral surface of the housing 11. An eccentric shaft 32 that is eccentric with respect to the rotation axis is provided at the upper end of the drive shaft 30, and the eccentric shaft 32 is rotatably connected to the center of the lower surface of the movable scroll member 22.

  The motor 40 includes a rotor 41 fixed to the drive shaft 30 and a stator 42 fixed to the inner peripheral surface of the housing 11, and is disposed below the compression mechanism 20.

  In the scroll compressor configured as described above, when the drive shaft 30 is rotated by the motor 40, the movable scroll member 22 revolves with respect to the fixed scroll member 21 by the eccentric shaft 32. At that time, each pin 22b revolves along the inner peripheral surface of each circular hole 23a as the movable scroll member 22 revolves, whereby the rotation of the movable scroll member 22 is restricted.

  At that time, the support member 23 provided with each circular hole 23a and the movable scroll member 22 provided with each pin 22b have a difference in thermal expansion during operation due to a difference in material (difference in linear expansion coefficient). That is, when each pin 22b and each circular hole 23a are formed such that the pitch circle radius R1 of each pin 22b and the pitch circle radius R2 of each circular hole 23a are equal at normal temperature (about 20 ° C.), Increases, a dimensional difference occurs between the pitch circle radii R1 and R2, and the rotation of the movable scroll member 22 cannot be sufficiently restricted. Such rotation of the movable scroll member 22 causes a decrease in volumetric efficiency and adiabatic compression efficiency in the compressor.

  Therefore, a measurement test of the volume efficiency and adiabatic compression efficiency of a compressor formed so that the pitch circle radius R1 of each pin 22b is smaller than the pitch circle radius R2 of each circular hole 23a was performed. The results shown in (1) were obtained. In this test, carbon dioxide was used as a refrigerant, and volumetric efficiency and adiabatic compression efficiency were measured under the conditions of a compression ratio of 2.5 and a rotational speed of 6500 rpm. The volumetric efficiency here refers to the volume of the compression space at which the gas remaining in the dead space between the spiral bodies 21a and 22a expands until reaching the evaporation pressure after the start of the suction stroke, and the actual suction is performed. The difference between the volume of the compression space when it reaches the maximum and Vr is Vr, and the stroke volume is Vth, the ratio expressed by Vr / Vth. The adiabatic compression efficiency refers to the ratio between the work required for actually compressing the gas and the work obtained theoretically.

  As a result of the measurement test, when the difference between the pitch circle radius R1 of each pin 22b and the pitch circle radius R2 of each circular hole 23a is 0.1% of the pitch circle radius R2 of each circular hole 23a, volume efficiency and adiabatic compression are achieved. The result was the maximum efficiency. In addition, the range in which 99% or more of the maximum efficiency can be obtained is 0.05% or more and 0.15% or less, and within this range, each pin 22b can be accurately aligned along the inner peripheral surface of each circular hole 23a. It can be made to turn well, and an effect almost equivalent to the case of 0.1% can be obtained.

  Thus, according to this embodiment, since the supporting member 23 that supports the movable scroll member 22 is formed of an iron-based material and the movable scroll member 22 is formed of an aluminum-based material, the movable scroll member 22 is reduced in weight. And the load on the motor 40 can be reduced. In this case, the plurality of pins 22b provided in the movable scroll member 22 and the plurality of circular holes 23a provided in the support member 23 are arranged such that the pitch circle radius R1 of each pin 22b of each pin 22b is the pitch circle radius of each circular hole 23a. Since the movable scroll member 22 is formed of an aluminum-based material having a thermal expansion coefficient larger than that of the iron-based material, the pitch circle radii R1, R2 due to the difference in thermal expansion during operation are formed. Can be absorbed. Thereby, during operation, each pin 22b can be accurately swung along the inner peripheral surface of each circular hole 23a, and the decrease in volumetric efficiency and adiabatic compression efficiency due to the rotation of the movable scroll member 22 can be suppressed. it can.

  Further, the difference between the pitch circle radius R1 of each pin 22b and the pitch circle radius R2 of each circular hole 23a is set to be 0.05% or more and 0.15% or less of the pitch circle radius R2 of each circular hole 23a. In this range, it is possible to obtain substantially the same effect as in the case of 0.1%, which is the maximum value of volumetric efficiency and adiabatic compression efficiency, and each pin 22b can be accurately aligned along the inner peripheral surface of each circular hole 23a. It is extremely effective in turning well.

Side surface sectional drawing of the scroll compressor which shows one Embodiment of this invention Top view showing pins and circular holes Diagram showing the relationship between volumetric efficiency and pitch circle radius dimensional difference Diagram showing the relationship between adiabatic compression efficiency and dimensional difference in pitch circle radius

Explanation of symbols

  DESCRIPTION OF SYMBOLS 20 ... Compression mechanism, 21 ... Fixed scroll member, 21a ... Spiral body, 22 ... Movable scroll member, 22a ... Spiral body, 22b ... Pin, 23 ... Support member, 23a ... Circular hole, 30 ... Drive shaft, 32 ... Eccentric shaft 40 ... motor.

Claims (3)

A drive shaft having an eccentric shaft eccentric with respect to the rotation shaft at one end, a fixed scroll member having a spiral body at one end surface, and a spiral body facing the spiral body of the fixed scroll member at one end surface; A movable scroll member that revolves with respect to the fixed scroll member around the rotational axis of the drive shaft by eccentric rotation of the eccentric shaft, and the pins projecting from the circumferential direction on the other end surface of the movable scroll member on the compressor body side The rotation of the movable scroll member is restricted by engaging with circular holes provided at a plurality of locations in the circumferential direction of the member and turning each pin along the inner peripheral surface of each circular hole as the movable scroll member revolves. In the scroll type compressor
The movable scroll member is formed by a member having a larger coefficient of thermal expansion than a member provided with each circular hole,
A scroll compressor characterized in that each pin and each circular hole are formed so that the pitch circle radius of each pin is smaller than the pitch circle radius of each circular hole. The scroll compressor according to claim 1, wherein the member provided with each circular hole is formed of an iron-based material, and the movable scroll member is formed of an aluminum-based material. Each pin and each circular hole are formed such that the difference between the pitch circle radius of each pin and the pitch circle radius of each circular hole is 0.05% or more and 0.15% or less of the pitch circle radius of each circular hole. The scroll compressor according to claim 2, wherein

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