JP2009250169A - Compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To minimize the looseness of a rotary shaft regardless of a temperature change without making thrust pressure act on the rotary shaft. <P>SOLUTION: In a compressor 1, the rotary shaft 16 of a compression mechanism 10 is rotatably supported by a housing 2 via bearings 30 and 31, and the bearings 30 and 31 are constituted of a rolling bearing 31 composed of an outer ring 31a, an inner ring 31b and a rolling element 31c arranged between these inner-outer rings, and the outer ring 31a of the rolling bearing 31 is fixed to the housing 2 by being pressed in an outer ring press-in part 32 of the housing 2. Three slits 33 are formed at intervals in the circumferential direction in the outer ring press-in part 32 of the housing 2. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a compressor that compresses a refrigerant.

  A conventional compressor of this type is disclosed in Patent Document 1. In this compressor, a compression mechanism portion is disposed in a housing, and both ends of a rotation shaft of the compression mechanism portion are rotatably supported by the housing by a slide bearing portion and a rolling bearing portion. A thrust pressure (preload) is applied to the rotating shaft by the elastic force of the elastic body. In addition, there are some which apply a spring pressure such as a leaf spring instead of an elastic body.

That is, as shown in FIG. 5A, the rolling bearing portion 100 includes an outer ring 101, an inner ring 102, and a rolling element 103 disposed therebetween, and the rolling element 103, the outer ring 101, and the inner ring 102. There is an internal gap d (d = d1 + d2 + d3 + d4). This internal gap d causes a backlash of the rotating shaft 110 and causes vibration and noise during operation. In order to prevent such rattling or the like, a thrust pressure F due to spring pressure is applied to the rotating shaft 110. When the thrust pressure F is applied to the rotating shaft 110, the internal gap of the rolling bearing portion 100 can be substantially eliminated as shown in FIG. This prevents the rotating shaft 110 from rattling.
Japanese Patent No. 3671849

  However, in the configuration in which the thrust pressure is applied to the rotating shaft by an elastic body, a spring, or the like as in the conventional example, there are problems that the number of parts increases, the structure becomes complicated, and the entire length of the rotating shaft becomes long.

  Here, when the rolling bearing portion is press-fitted into the outer ring press-fitting portion of the housing, pressure input acts on the rolling bearing portion. It is conceivable to reduce the diameter of the outer ring by this pressure input and to make the internal clearance of the rolling bearing portion substantially zero. In the means using such pressure input, the internal gap can be made zero at a certain predetermined temperature. However, when the temperature becomes higher than the predetermined temperature, the outer ring press-fitted portion expands and the internal gap becomes large. . In particular, since the compressor has a wide operating temperature range, the influence of temperature is great, and it is impossible to prevent the rotating shaft from rattling.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a compressor that can prevent backlash of a rotating shaft as much as possible without causing a thrust pressure to act on the rotating shaft and irrespective of a temperature change.

  The invention according to claim 1, which achieves the above object, comprises a housing in which a rotating shaft of a compression mechanism portion is rotatably supported via a bearing portion, and the bearing portion includes an outer ring, an inner ring, and a rolling element disposed therebetween. A compressor that is fixed to the housing by press-fitting the outer ring of the rolling bearing portion into the outer ring press-fitting portion of the housing. The outer ring press-fitting portion of the housing is spaced apart in the circumferential direction. A plurality of slits are provided.

  A second aspect of the present invention is the compressor according to the first aspect, wherein the plurality of slits are provided at substantially equal intervals in the circumferential direction.

  A third aspect of the present invention is the compressor according to the first or second aspect, wherein the outer ring press-fitting portion is installed in a refrigerant discharge path of the refrigerant discharged from the compression mechanism portion.

  Invention of Claim 4 is the compressor in any one of Claims 1-3, Comprising: The bearing part which supports a rotating shaft is provided in two places of the position near a compression mechanism part, and a distant position, The distant position of the compression mechanism portion is constituted by the rolling bearing portion.

  A fifth aspect of the present invention is the compressor according to any one of the first to fourth aspects, wherein the compression mechanism section is disposed in the block in which the cylinder chamber is formed, the cylinder chamber, and is fixed to the rotating shaft. And the rotating shaft also serves as the rotating shaft of the electric motor.

  According to the first aspect of the present invention, since the outer ring press-fit portion can be elastically deformed in the radial direction by the slit, the outer ring press-fitted by the elastic deformation is reduced in diameter, so that the internal clearance of the rolling bearing portion is substantially zero. In this state, the rotating shaft can be rotatably supported. When the temperature increases, the outer ring press-fitting part itself expands in the direction of increasing its diameter, but the outer ring press-fitting part biases the outer ring in a direction of reducing the diameter by elastic deformation, so that the internal clearance of the rolling bearing part is reduced. It won't be too big. As described above, it is possible to prevent rattling of the rotating shaft as much as possible without causing a thrust pressure to act on the rotating shaft, and irrespective of temperature changes.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, the rotating shaft can be supported while preventing the eccentricity of the rotating shaft as much as possible.

  According to the invention of claim 3, in addition to the effects of the invention of claim 1 or claim 2, the rolling bearing portion is exposed to a high-temperature discharged refrigerant and thus becomes high temperature. The rotating shaft can be supported without increasing the gap.

  According to the invention of claim 4, in addition to the effects of the inventions of claims 1 to 3, the position close to the compression mechanism portion can be easily changed by using the oil supply path to the sliding portion of the compression mechanism portion. For example, a sliding bearing can be easily employed. On the other hand, when the sliding bearing portion is employed at a position far from the compression mechanism portion, it is necessary to provide an oil supply path separately, which complicates the configuration. As described above, the bearing portion of the rotary shaft can be configured with a simple configuration by setting the bearing portion far from the compression mechanism portion as the sliding bearing portion.

  According to the invention of claim 5, in addition to the effects of the inventions of claims 1 to 4, no preload acts in the thrust direction of the rotating shaft, so that rotation is performed while maintaining a clearance between the block of the compression mechanism and the rotor. The position of the shaft in the thrust direction can be easily adjusted.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 4 show an embodiment of the present invention, FIG. 1 is a sectional view of an electric compressor, FIG. 2 is an inner view showing a state in which a rolling bearing portion is press-fitted into an outer ring press-fitting portion of a motor housing member, and FIG. a) is a cross-sectional view of the rolling bearing portion before press-fitting, FIG. 3 (b) is a cross-sectional view of the rolling bearing portion after press-fitting, and FIG. 4 shows the case of press-fitting into the outer ring press-fitted portion without slits and the outer ring press-fitted portion with slits. It is a characteristic diagram which shows the relationship between the internal clearance at the time of press-fit, and temperature.

  As shown in FIG. 1, the electric compressor 1 has a housing 2. The housing 2 includes a substantially cylindrical compressor housing member 3, a front housing member 4 disposed on one opening side surface of the compressor housing member 3, and a motor housing disposed on the other opening side surface of the compressor housing member 3. It is comprised from the member 5. The compressor housing member 3, the front housing member 4 and the motor housing member 5 are all made of an aluminum alloy.

  The compression mechanism unit 10 is accommodated in the compressor housing member 3. The compression mechanism unit 10 includes a cylinder block 11 and a front side block 12 and a rear side block 13 that are respectively disposed on both side surfaces of the cylinder block 11. The blocks 11, 12 and 13 are fixed by bolts (not shown), and a cylinder chamber 14 is formed in the blocks 11, 12 and 13. The cylinder block 11 and the side blocks 12 and 13 on both sides are made of an aluminum alloy in the same manner as the housing members 3, 4 and 5.

  A rotor 15 is accommodated in the cylinder chamber 14. A rotation shaft 16 passes through the center of the rotor 15, and the rotor 15 and the rotation shaft 16 are fixed. The rear side of the rotating shaft 16 protrudes outside from the rear side block 13 and also serves as a rotating shaft of the electric motor 6 described below. The rotating shaft 16 is rotatably supported by the rear side block 13 and the motor housing member 5, and this supporting structure will be described in detail below.

  Vane grooves 17 that open to the outer peripheral surface are formed at equally spaced positions on the outer peripheral side of the rotor 15. A vane 18 is disposed in each vane groove 17 so as to protrude freely. A high-pressure refrigerant supply path (not shown) is opened at the bottom of the vane groove 17. Each vane 18 is configured to be biased in the protruding direction by the back pressure of the high-pressure refrigerant. Each vane 18 moves while contacting the inner wall of the cylinder chamber 14 by the biasing force in the protruding direction as described above when the rotary shaft 16 rotates. A plurality of compression chambers are formed in the cylinder chamber 14 between the adjacent vanes 18. Each compression chamber expands its volume in accordance with the rotation of the rotor 15 and repeats a suction stroke for sucking refrigerant, a compression stroke for reducing the volume, compressing the sucked refrigerant, and discharging the refrigerant.

  The refrigerant suction path 20 communicates a suction port (not shown) and a cylinder suction port (not shown) that opens to the cylinder chamber 14. The refrigerant is supplied to the cylinder chamber 14 through the refrigerant suction path 20.

  The refrigerant discharge path 21 communicates a cylinder discharge port (not shown) that opens to the cylinder chamber 14 and a discharge port 21a. The compressed refrigerant in the cylinder chamber 14 is discharged through the refrigerant discharge path 21. The refrigerant discharge path 21 passes through a motor housing chamber 5a of the electric motor 6 described below.

  The electric motor 6 is housed in the motor housing chamber 5 a of the motor housing member 5. The electric motor 6 includes a motor rotor 23 fixed to the rotating shaft 16 and a stator 24 fixed to the inner peripheral surface of the motor housing member 5.

  On the outer periphery of the motor rotor 23, S poles and N poles are alternately magnetized in the circumferential direction. The stator 24 includes a core 24a and a coil 24b wound around the core 24a. A drive current is supplied to the coil 24b from the motor control circuit unit 25.

  The motor housing member 5 and the compressor housing member 3 are provided with an oil storage chamber 26 below the motor housing chamber 5a. The oil storage chamber 26 communicates with the discharge port 21a via an oil return passage (not shown) so that the oil separated at the discharge port 21a flows therein. In addition, an oil supply passage (not shown) is opened in the oil storage chamber 26, and the other end side of the oil supply passage is opened in an oil lubrication portion of the compression mechanism section 10. The oil lubrication site also includes a sliding bearing 30 described below.

  Next, the support structure of the rotating shaft 16 will be described. As shown in FIG. 1, the rotating shaft 16 is rotatably supported by a sliding bearing portion 30 provided in the vicinity of the compression mechanism portion 10 and a rolling bearing portion 31 provided in a position far from the compression mechanism portion 10. ing.

  The sliding bearing portion 30 is formed by the peripheral wall portion of the rotation shaft hole 13 a of the rear side block 13. Oil is supplied from the oil storage chamber 26 between the peripheral wall portion of the rotation shaft hole 13 a and the rotation shaft 16.

  As shown in detail in FIG. 3A, the rolling bearing portion 31 includes an outer ring 31a, an inner ring 31b, and a spherical rolling element 31c disposed therebetween. The rolling element 31c, the outer ring 31a, and the inner ring An internal gap d (d = d1 + d2 + d3 + d4) exists between 31b. The rotating shaft 16 is inserted into the inner ring 31b. As shown in FIGS. 1 and 2, the outer ring 31 a is press-fitted into an outer ring press-fit portion 32 provided integrally with the motor housing member 5. The outer ring press-fit portion 32 is cylindrical, and three slits 33 are provided at equal intervals in the circumferential direction. The outer ring press-fit portion 32 is partitioned by the three slits 33 into three press-fit pieces 32a. Each press-fitting piece 32a is easily elastically deformed in the radial direction. When the rolling bearing portion 31 is press-fitted, the outer ring 31a is allowed to be inserted by elastic deformation and the outer ring 31a is reduced in diameter by the elastic return force of the press-fitting piece 32a. Transforms into As a result, the rolling bearing portion 31 is press-fitted with almost no internal gap as shown in FIG.

  In the above configuration, when the electric motor 6 is energized, a rotational force is generated in the motor rotor 23, and the motor rotor 23 of the electric motor 6, the rotary shaft 16, and the rotor 15 of the compression mechanism unit 10 rotate. Then, the compression mechanism unit 10 is driven, the refrigerant sucked from the suction port (not shown) is sucked into the cylinder chamber 14 of the compression mechanism unit 10, and the refrigerant compressed in the cylinder chamber 14 of the compression mechanism unit 10 is discharged. Is done. The refrigerant discharged from the compression mechanism unit 10 passes through the motor housing chamber 5a and is discharged out of the housing 2 through the discharge port 21a. During the refrigerant compression operation process, the rotating shaft 16 is supported by the sliding bearing portion 30 and the rolling bearing portion 31 and rotates relative to the housing 2.

  Thus, the rolling bearing portion 31 that supports the rotating shaft 16 is press-fitted into the outer ring press-fit portion 32 of the motor housing member 5, and the outer ring press-fit portion 32 is provided with a plurality of slits 33 at intervals in the circumferential direction. Yes. Accordingly, since the outer ring press-fit portion 32 can be elastically deformed in the radial direction by the slit 33, the outer ring 31a press-fitted by this elastic deformation is reduced in diameter, so that the internal clearance of the rolling bearing portion 31 is substantially zero. The rotating shaft 16 can be rotatably supported. When the temperature rises, the outer ring press-fit portion 32 itself expands in the direction of increasing its diameter, but the outer ring press-fit portion 32 urges the outer ring 31a in a direction of reducing its diameter by elastic deformation, so the rolling bearing portion 31. The internal gap of the is not so large. FIG. 4 shows changes in the amount of internal gap due to temperature changes when the slit 33 is not provided in the outer ring press-fitting portion 32 and when the slit 33 is provided. d can be suppressed within 5 μm.

  As described above, it is possible to prevent rattling of the rotating shaft 16 as much as possible without applying a thrust pressure to the rotating shaft 16 and irrespective of the temperature change.

  In the present invention, the rolling bearing portion 31 has the internal gap d substantially zero by the outer ring 31a being pressed in the direction of diameter reduction. Therefore, the rolling bearing portion 31 has a small internal gap d before press-fitting. It is preferable to use it.

  In this embodiment, the three slits 33 are provided at substantially equal intervals in the circumferential direction. Therefore, the rotating shaft 16 can be supported while preventing the rotating shaft 16 from being eccentric as much as possible. Of course, the number of the slits 33 may be two, or four or more.

  In this embodiment, the outer ring press-fit portion 32 is installed in the refrigerant discharge path 21 of the refrigerant discharged from the compression mechanism portion 10. Therefore, although the rolling bearing portion 31 is exposed to the high-temperature discharged refrigerant and becomes high temperature, the rotating shaft 16 can be supported without increasing the internal gap of the rolling bearing portion 31 for the reasons described above.

  In this embodiment, the sliding bearing portion 30 is provided at a position close to the compression mechanism portion 10, and the rolling bearing portion 31 is provided at a position far from the compression mechanism portion 10. The position close to the compression mechanism unit 10 can be easily supplied with oil by using an oil supply path to the sliding portion of the compression mechanism unit 10, and the sliding bearing unit 30 can be easily adopted. On the other hand, when the sliding bearing portion is adopted at a position far from the compression mechanism portion 10, it is necessary to provide an oil supply path separately, and the configuration becomes complicated. As described above, the bearing portion of the rotary shaft 16 can be configured with a simple configuration by using the rolling bearing portion 31 as the bearing portion far from the compression mechanism portion 10. In addition, it is good also considering the two bearing parts which support the rotating shaft 16 as a rolling bearing part together.

  In this embodiment, the rotating shaft 16 also serves as the rotating shaft of the electric motor 6. Accordingly, since the preload does not act in the thrust direction of the rotary shaft 16, the clearance between the blocks 11 and 13 of the compression mechanism unit 10 and the rotor 15 can be maintained.

  In the above embodiment, the rolling element 31c of the rolling bearing portion 31 is a sphere, but may be any one that rotates, and may be a cylinder.

1 is a cross-sectional view of an electric compressor according to an embodiment of the present invention. It is an inner surface figure which shows one Embodiment of this invention and shows the state which press-fitted the rolling bearing part to the outer ring press-fit part of the motor housing member. 1 shows an embodiment of the present invention, in which (a) is a sectional view of a rolling bearing portion before press-fitting, and (b) is a sectional view of the rolling bearing portion after press-fitting. FIG. 5 is a characteristic diagram showing the relationship between the internal gap and the temperature when pressed into the outer ring press-fitted part without slits and when pressed into the outer ring press-fitted part with slits according to one embodiment of the present invention. A prior art example is shown, (a) is sectional drawing of the rolling bearing part before press fit, (b) is sectional drawing of the rolling bearing part after press fitting.

Explanation of symbols

1 Electric compressor (compressor)
2 Housing 10 Compression mechanism 11 Cylinder block (block)
12 Front side block (block)
13 Rear side block (block)
14 Cylinder chamber 15 Rotor 16 Rotating shaft 21 Refrigerant discharge passage 31 Rolling bearing portion 31a Outer ring 31b Inner ring 31c Rolling element 32 Outer ring press-fitting portion

Claims (5)

A rotation shaft (16) of the compression mechanism (10) is rotatably supported by the housing (2) via a bearing, and the bearing is disposed between the outer ring (31a) and the inner ring (31b). It is comprised by the rolling bearing part (31) which consists of a rolling element (31c), and the said outer ring | wheel (31a) of the said rolling bearing part (31) is press-fitted in the outer ring press-fit part (32) of the said housing (2). A compressor (1) fixed to the housing (2),
The compressor (1), wherein the outer ring press-fitting portion (32) of the housing (2) is provided with a plurality of slits (33) at intervals in the circumferential direction. Compressor (1) according to claim 1,
The compressor (1), wherein the plurality of slits (33) are provided at substantially equal intervals in the circumferential direction. A compressor (1) according to claim 1 or claim 2,
The compressor (1), wherein the outer ring press-fitting portion (32) is installed in a refrigerant discharge path (21) of the refrigerant discharged from the compression mechanism portion (10). A compressor (1) according to any one of claims 1 to 3,
The bearing portions that support the rotating shaft (16) are provided at two locations, a position close to the compression mechanism portion (10) and a position far from the compression mechanism portion (10), and a position farther from the compression mechanism portion (10) is the rolling bearing. The compressor (1) characterized by comprising a part (31). A compressor (1) according to any one of claims 1-4,
The compression mechanism section (10) includes a block (11, 12, 13) in which a cylinder chamber (14) is formed, and a rotor disposed in the cylinder chamber (14) and fixed to the rotating shaft (16). (15)
The compressor (1), wherein the rotating shaft (16) also serves as a rotating shaft of an electric motor (6).

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