JP2008220133A - Driving motor and compressor therewith - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving motor and a compressor therewith, capable of decreasing the flow of hydraulic oil to an air gap and decreasing the hydraulic oil viscosity shearing loss in the air gap. <P>SOLUTION: This driving motor 1 includes a rotor 2 and a stator 3. The rotor 2 has a rotor core 8 and a pair of the first edge plate 4 and the second edge plate 5. The rotator core 8 is constituted by laminating a plurality of laminated steel plates 9. The pair of the first edge plate 4 and the second edge plate 5 is disposed on both the edges of the rotor core 8. The stator 3 is disposed, apart from a side circumferential surface of the rotor 2, to form an air gap 10 which is a gap in which gas fluid passes at the space to the rotor 2 at the outside in the radial direction of the rotor 2. At least the outer periphery of the first edge plate 4, positioned on the upstream side of the gas fluid passing through the air gap 10 among the pair of edge plates 4, 5, is equal to the inner periphery of the stator 3 or larger. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a drive motor used in an environment in which a gas fluid and oil circulate, and a compressor including the drive motor.

2. Description of the Related Art Conventionally, in a compressor for compressing refrigerant in a refrigerant circuit, etc., a compression provided with a drive motor in which an oil separator for separating compressed gas and lubricating oil is attached to the upper or lower portion of the motor rotor (See Patent Document 1).
JP 2001-218411 A

  However, in the drive motor described in Patent Document 1, the oil separation structure is provided at the motor end, but the oil flowing into the inlet of the air gap between the motor rotor and the motor stator is sufficiently removed. Can not do it. For this reason, shear loss of the motor rotor (hereinafter referred to as oil viscosity shear loss) due to oil viscosity in the air gap cannot be avoided.

Further, in the case of an ultra-high pressure refrigerant (for example, carbon dioxide (CO ₂ )) used in a much higher pressure environment than a conventional chlorofluorocarbon refrigerant or the like, the gas load applied to the sliding portion of the drive motor becomes large. Moreover, in order to maintain the sealing characteristic of the gas leaking part under high differential pressure, it is necessary to use high viscosity oil. For these reasons, when high viscosity oil is used, the viscous shear loss of the oil that has entered the air gap further reduces the efficiency of the fluid machine.

  Furthermore, in the ultra high pressure refrigerant such as carbon dioxide as described above, the density of the refrigerant gas is high, and therefore the density difference from the oil is small (in other words, the density ratio of gas to oil is high). For this reason, even if it separates oil and gas once using centrifugal force etc., it will be mixed again immediately, and there also exists a problem that gas-liquid separation is difficult. For example, Table 1 shows two types of refrigerant (R410A, carbon dioxide) and oil corresponding to each of the high pressure side (compressor discharge side) and Table 2 shows the low pressure side (compressor suction side). Although the density comparison is shown, the density difference with the oil is smaller in the case of the ultra-high pressure refrigerant such as carbon dioxide for both the high-pressure side and the low-pressure side (that is, the gas with respect to the oil) It can be seen that the density ratio is high.

本発明の課題は、エアギャップへの油の流入を低減でき、エアギャップにおける油粘性せん断損失を低減できる駆動モータおよびそれを備えた圧縮機を提供することにある。

The subject of this invention is providing the drive motor which can reduce inflow of the oil to an air gap, and can reduce the oil viscous shear loss in an air gap, and a compressor provided with the same.

  The drive motor of the first invention includes a rotor and a stator. The rotor has a rotor core and a pair of first end plate and second end plate. The rotor core is configured by laminating a plurality of laminated steel plates. The pair of first end plates and second end plates are disposed at both ends of the rotor core. The stator is arranged away from the side peripheral surface of the rotor so as to form an air gap that is a gap through which the gas fluid passes between the stator and the rotor on the radially outer side of the rotor. Of the pair of end plates, the outer diameter of the first end plate located at least upstream of the gas fluid flowing through the air gap is equal to or greater than the inner diameter of the stator.

  Here, since the outer diameter of the first end plate located on the upstream side of the gas fluid is equal to or larger than the inner diameter of the stator, the mixed fluid of gas and oil that is about to enter the air gap is a protruding portion of the first end plate. Is effectively separated into gas and liquid under centrifugal force. Accordingly, it is possible to suppress the inflow of oil into the air gap. As a result, the oil viscous shear loss can be sufficiently reduced.

The drive motor of the second invention is the drive motor of the first invention, wherein the protruding length A1 of the portion of the first end plate protruding from the rotor core, the width B of the air gap, and the first end plate The relationship between the distance C1 from the tip to the end face of the stator is
A1 ≧ B, and
A1 ≧ (C1 / B) ² × B.

  Here, by defining the position of the first end plate on the upstream side of the gas flow and its outer diameter so as to satisfy the above two formulas, the centrifugal force applied to the oil from the protruding portion of the first end plate at the inlet of the air gap The force can be sufficiently increased, and more effective gas-liquid separation and prevention of oil from flowing into the air gap can be achieved. As a result, it is possible to further reduce the oil viscous shear loss.

  The drive motor of the third invention is the drive motor of the first invention or the second invention, wherein the outer diameter of the second end plate is not less than the outer diameter of the first end plate.

  Here, since the outer diameter of the second end plate is greater than or equal to the outer diameter of the first end plate, not only can the oil flow into the air gap be blocked from the upstream side, but also from the downstream side, and the oil viscous shear Loss can be further reduced.

A drive motor according to a fourth aspect of the present invention is the drive motor according to any one of the first to third aspects of the present invention, wherein the protrusion length A2 of the portion protruding from the rotor core of the second end plate and the width B of the air gap And the distance C2 from the tip of the second end plate to the end face of the stator is
A2 ≧ B, and
A2 ≧ (C2 / B) ² × B.

  Here, by defining the position of the second end plate on the downstream side and its outer diameter so as to satisfy the above two formulas, the inflow of oil into the air gap due to the backflow from the downstream side can be effectively avoided, It becomes possible to further reduce the viscous shear loss.

  A compressor according to a fifth aspect includes the drive motor according to the first to fourth aspects.

  Here, since the compressor includes a drive motor in which the outer diameter of the first end plate located on the upstream side of the gas fluid is equal to or larger than the inner diameter of the stator, the inflow of oil into the air gap is effectively suppressed. This makes it possible to sufficiently reduce the oil-viscous shear loss. This makes it possible to manufacture a compressor capable of reducing power consumption and improving discharge pressure.

  A compressor according to a sixth aspect of the present invention is the compressor according to the fifth aspect of the present invention, and uses a refrigerant made of carbon dioxide as the gas fluid.

  Here, an ultrahigh pressure refrigerant made of carbon dioxide having a high gas density and a small density difference from oil is used as the gas fluid. However, even in a compressor using such a carbon dioxide refrigerant, the first end is also used. The protruding portion of the plate can effectively prevent oil from flowing into the air gap in the vicinity of the air gap inlet. Moreover, even if high viscosity oil corresponding to a carbon dioxide refrigerant is employed, an increase in viscosity loss in the air gap can be avoided.

  According to the first aspect of the present invention, the gas and oil mixed fluid that is about to enter the air gap can be gas-liquid separated by the protruding portion of the first end plate. Therefore, the inflow of oil into the air gap can be suppressed. As a result, oil viscous shear loss can be sufficiently reduced.

  According to the second invention, gas-liquid separation can be performed more effectively and oil can be prevented from flowing into the air gap. As a result, oil viscous shear loss can be further reduced.

  According to the third aspect of the invention, not only can the oil flow into the air gap be blocked from the upstream side, but also from the downstream side, and the oil viscous shear loss can be further reduced.

  According to the fourth invention, the inflow of oil into the air gap due to the backflow from the downstream side can be effectively avoided, and the oil viscous shear loss can be further reduced.

  According to the fifth invention, the inflow of oil into the air gap can be effectively suppressed, and the oil viscosity shear loss can be sufficiently reduced. As a result, the power consumption can be reduced and the discharge pressure can be improved. Possible compressors can be manufactured.

  According to the sixth aspect of the invention, even in a compressor using carbon dioxide refrigerant, oil can be effectively prevented from flowing into the air gap near the inlet of the air gap by the protruding portion of the first end plate. Moreover, even if high viscosity oil corresponding to a carbon dioxide refrigerant is employed, an increase in viscosity loss in the air gap can be avoided.

  Next, an embodiment of a drive motor of the present invention and a compressor including the drive motor will be described with reference to the drawings.

[Embodiment]
<Compressor configuration>
Hereinafter, the structure of the compressor provided with the motor rotor 2 of the embodiment will be described.

  As shown in FIG. 1, the rotary compressor 101 according to the embodiment mainly includes a vertically long cylindrical hermetic dome-shaped casing 100, a rotary compression mechanism unit 115, a drive motor 1, a suction pipe 119, a discharge pipe 120, And a terminal 195. The rotary compressor 101 incorporates the motor rotor 2 according to the embodiment inside the casing 100.

  Hereinafter, the components of the rotary compressor 101 will be described in detail.

[Details of components of the rotary compressor]
(1) Casing The casing 100 of the rotary compressor 101 accommodates a rotary compression mechanism portion 115 that mainly compresses a gas refrigerant made of carbon dioxide, and a drive motor 1 disposed above the rotary compression mechanism portion 115. Has been. The rotary compression mechanism 115 and the drive motor 1 are connected by a crankshaft 117 that is disposed so as to extend in the vertical direction in the casing 100.

(2) Drive Motor As shown in FIG. 3, the drive motor 1 is a direct current motor in the present embodiment, and mainly includes an annular motor stator 3 fixed to the inner wall surface of the casing 100, and a motor. A motor rotor 2 is rotatably housed inside the stator 3 with a slight gap (air gap passage).

  The motor rotor 2 includes a rotor core 8 formed by laminating a plurality of laminated steel plates 9, a pair of lower end plates 4 (first end plates) and upper ends disposed at both ends of the rotor core 8. It has a plate 5 (second end plate) and a magnet plate 11. The lower end plate 4 and the upper end plate 5 sandwich a plurality of laminated steel plates 9 from both ends of the rotor core 8 and are fastened together with the plurality of laminated steel plates 9 by rivets (not shown). A crankshaft 117 is fixed to the motor rotor 2 along the rotation axis. Magnet plates 11 made of plate-like permanent magnets are inserted into four slits extending in the axial direction formed in the rotor core 8. Reference numeral 15 denotes an oil separation plate.

  The motor stator 3 is separated from the side circumferential surface of the motor rotor 2 so that an air gap 10 is formed between the motor rotor 2 and the motor rotor 2 in the radial direction. Are arranged. Further, a copper wire is wound around a tooth portion (not shown) of the motor stator 3, and a coil end 153 (see FIG. 1) is formed above and below. Furthermore, the outer peripheral surface of the motor stator 3 is provided with core cut portions 14 that are notched at a plurality of positions from the upper end surface to the lower end surface of the motor stator 3 and at predetermined intervals in the circumferential direction. .

  The gas fluid compressed by the rotary compression mechanism 115 moves from the lower end plate 4 side to the upper end plate 5 side through the air gap 10 and the gas passage 7 inside the motor rotor 2, and rises above the casing 100. To do.

  The outer diameter D2 of the lower end plate 4 positioned at least on the upstream side of the gas fluid flowing through the air gap 10 out of the pair of lower end plate 4 and upper end plate 5 is for preventing the inflow of oil into the air gap 10. The inner diameter D1 of the motor stator 3 is greater than or equal to.

Further, in order to increase the centrifugal force acting on the oil at the inlet of the air gap 10, as shown in FIG. 4, the protruding length A1 of the portion 4a protruding from the rotor core 8 of the lower end plate 4, The relationship between the width B of the air gap 10 and the distance C1 from the tip of the lower end plate 4 to the end face of the motor stator 3 is
A1 ≧ B (Formula 1), and
A1 ≧ (C1 / B) ² × B (Formula 2)
The protruding length A1 of the lower end plate 4 is set so as to be.

  Here, (Equation 2) indicates that the distance C1 from the tip of the lower end plate 4 to the end face of the motor stator 3 is normally set to be equal to or greater than the width B of the air gap 10 (C1 ≧ B), and In order to increase the centrifugal force acting on the oil between the distance C1 as the distance C1 increases, the lower end plate 4 protrudes by the square of the increment (C1 / B) of the distance C1 with respect to the width of the air gap 10. Considering that the length A1 needs to be larger than the width B of the air gap 10, the above equation is used.

(3) Rotary compression mechanism section As shown in FIGS. 1 and 2, the rotary compression mechanism section 115 mainly includes a crankshaft 117, a piston 121, a bush 122, a front head 123, and a cylinder block 124. And the rear head 125. The rotary compression mechanism 115 is immersed in oil L stored at the bottom of the casing 100, and the oil L is supplied to the rotary compression mechanism 115 by differential pressure. Hereinafter, the components of the rotary compression mechanism unit 115 will be described in detail.

a) Cylinder Block As shown in FIGS. 1 and 2, the cylinder block 124 is formed with a cylinder hole 124a, a suction hole 124b, a discharge passage 124c, a bush accommodation hole 124d, and a blade accommodation hole 124e. As shown in FIGS. 1 and 2, the cylinder hole 124 a is a cylindrical hole that penetrates along the thickness direction. The suction hole 124b extends from the outer peripheral wall surface to the cylinder hole 124a. The discharge passage 124c is formed by cutting out a part of the inner peripheral side of the cylindrical portion that forms the cylinder hole 124a. The bush receiving hole 124d is a hole that penetrates along the plate thickness direction, and is located between the suction hole 124b and the discharge passage 124c when viewed along the plate thickness direction. The blade accommodation hole 124e is a hole that penetrates along the plate thickness direction and communicates with the bush accommodation hole 124d.

  In the cylinder block 124, the eccentric shaft portion 117a of the crankshaft 117 and the rotor portion 121a of the piston 121 are accommodated in the cylinder hole 124a, and the blade portion 121b and the bush 122 of the piston 121 are accommodated in the bush accommodation hole 124d. In a state where the blade portion 121b of the piston 121 is accommodated in the accommodation hole 124e, the discharge head 124c is fitted to the front head 123 and the rear head 125 so as to face the front head 123 side. As a result, a cylinder chamber Rc1 is formed in the rotary compression mechanism 115, and this cylinder chamber Rc1 is partitioned by a piston 121 into a suction chamber communicating with the suction hole 124b and a discharge chamber communicating with the discharge passage 124c. Become. In this state, the rotor part 121a is fitted into the eccentric shaft part 117a.

b) Crankshaft The crankshaft 117 is provided with an eccentric shaft portion 117a at one end. The crankshaft 117 is fixed to the motor rotor 2 of the drive motor 1 on the side where the eccentric shaft portion 117a is not provided.

c) Piston The piston 121 has a substantially cylindrical rotor part 121a and a blade part 121b protruding outward in the radial direction of the rotor part 121a. The rotor portion 121a is inserted into the cylinder hole 124a of the cylinder block 124 while being fitted to the eccentric shaft portion 117a of the crankshaft 117. Thereby, when the crankshaft 117 rotates, the rotor part 121a performs a revolving motion around the rotation axis of the crankshaft 117. The blade portion 121b is accommodated in the bush accommodation hole 124d and the blade accommodation hole 124e. As a result, the blade portion 121b swings and moves forward and backward along the longitudinal direction.

d) Bush The bush 122 is a substantially semi-cylindrical member, and is accommodated in the bush accommodation hole 124d so as to sandwich the blade portion 121b of the piston 121.

e) Front Head The front head 123 is a member that covers the discharge path 124 c side of the cylinder block 124 and is fitted to the casing 100. A bearing portion 123a is formed on the front head 123, and a crankshaft 117 is inserted into the bearing portion 123a. The front head 123 has an opening (not shown) for guiding the refrigerant gas flowing through the discharge passage 124 c formed in the cylinder block 124 to the discharge pipe 120. And this opening is obstruct | occluded or open | released by the discharge valve (not shown) for preventing the reverse flow of refrigerant gas.

f) Rear Head The rear head 125 covers the opposite side of the cylinder block 124 to the discharge path 124c side. A bearing portion 125a is formed in the rear head 125, and a crankshaft 117 is inserted into the bearing portion 125a.

(4) Suction Pipe The suction pipe 119 is provided so as to penetrate the casing 100, and one end is fitted into the suction hole 124 b formed in the cylinder block 124, and the other end is connected to the outlet pipe 132 of the accumulator 131. It is inserted.

(5) Discharge pipe The discharge pipe 120 is provided so as to penetrate the upper wall portion of the casing 100.

<Features>
(1)
In the drive motor 1 of the embodiment, the outer diameter D2 of the lower end plate 4 positioned at least upstream of the gas fluid flowing through the air gap 10 of the pair of lower end plate 4 and upper end plate 5 is Since the inner diameter is greater than or equal to D1, the mixed fluid of gas and oil that is about to enter the air gap 10 receives centrifugal force from the protruding portion 4a of the lower end plate 4 and is effectively gas-liquid separated. Therefore, the inflow of oil into the air gap 10 can be effectively suppressed, and as a result, the oil viscous shear loss can be sufficiently reduced.

  Further, the drive motor 1 according to the embodiment can be changed only by increasing the diameter of the lower end plate 4 as compared with the configuration of the conventional drive motor, so that the structure of the drive motor is not complicated and the manufacturing cost is reduced. It is also possible to suppress the increase of.

(2)
Further, the drive motor 1 of the embodiment includes a motor stator from the protruding length A1 of the portion 4a protruding from the rotor core 8 of the lower end plate 4, the width B of the air gap 10, and the tip of the lower end plate 4. The relationship between the distance C1 to the end face of 3 is
A1 ≧ B (Formula 1), and
A1 ≧ (C1 / B) ² × B (Formula 2)
The protruding length A1 of the lower end plate 4 is set so that Thus, by defining the position of the lower end plate 4 on the upstream side of the gas flow and its outer diameter D2, the centrifugal force applied to the oil from the protruding portion 4a of the lower end plate 4 at the inlet of the air gap 10 is sufficient. Therefore, it is possible to more effectively separate the gas and liquid and prevent the oil from flowing into the air gap 10. As a result, it is possible to further reduce the oil viscous shear loss.

(3)
In the compressor 101 of the embodiment, the outer diameter D2 of the lower end plate 4 positioned at the upstream side of the gas fluid flowing through the air gap 10 of the pair of lower end plate 4 and upper end plate 5 is the inner diameter of the motor stator 3. Since the drive motor 1 that is equal to or greater than D1 is provided, the inflow of oil into the air gap 10 can be effectively suppressed, and the oil viscous shear loss can be sufficiently reduced. This makes it possible to manufacture a compressor capable of reducing power consumption and improving discharge pressure.

(4)
Further, the compressor 101 of the embodiment uses an ultra-high pressure refrigerant made of carbon dioxide having a high gas density and a small density difference from oil as the gas fluid, but compression using such a carbon dioxide refrigerant Even in the machine, it is possible to effectively prevent the oil from flowing into the air gap 10 by adopting a structure in which centrifugal force is applied to the oil from the protruding portion 4a of the lower end plate 4 in the vicinity of the inlet of the air gap 10. It becomes possible. Moreover, even if high viscosity oil corresponding to a carbon dioxide refrigerant is employed, an increase in viscosity loss in the air gap 10 can be avoided.

<Modification>
(A)
In the above embodiment, the lower end plate 4 on the upstream side of the gas flow protrudes from the rotor core 8, but further, oil flows into the air gap 10 from the downstream side (upper side in FIGS. 3 and 5). As shown in FIG. 5, the upper end plate 5 on the downstream side of the gas flow also protrudes from the rotor core 8 and the outer diameter D3 of the upper end plate 5 is prevented. May be larger than the outer diameter D2 of the lower end plate 4. As a result, not only can the oil flow into the air gap 10 be prevented from the upstream side, but also from the downstream side, and the oil viscous shear loss can be further reduced.

(B)
Furthermore, also in the modified example (A), in order to increase the centrifugal force acting on the oil at the outlet of the air gap 10,
As shown in FIG. 5, for the upper end plate 5,
Between the protrusion length A2 of the portion 5a protruding from the rotor core 8 of the upper end plate 5, the width B of the air gap 10, and the distance C2 from the tip of the upper end plate 5 to the end face of the motor stator 3 Relationship
A2 ≧ B (Formula 3), and
A2 ≧ (C2 / B) ² × B (Formula 4)
It is more preferable that the protruding length A2 of the upper end plate 5 is set.

  Here, (Equation 4) is the same as (Equation 2), and the distance C2 from the tip of the upper end plate 5 to the end face of the motor stator 3 is usually set to be equal to or larger than the width B of the air gap 10. In order to increase the centrifugal force acting on the oil in the distance C2 as the distance C2 increases (C2 ≧ B) and the square of the increment (C2 / B) of the distance C2 to the width of the air gap 10 Considering that it is necessary to make the protrusion length A2 of the upper end plate 5 larger than the width B of the air gap 10 by the amount, the above formula is obtained.

  Thus, by defining the position of the upper end plate 5 on the downstream side and its outer diameter D3, the inflow of oil into the air gap 10 due to the backflow from the downstream side can be effectively avoided, and the oil viscous shear loss can be further reduced. Further reduction is possible.

  The present invention can be applied to a drive motor used in an environment in which a gas fluid and oil circulate and a compressor including the drive motor.

  In addition to the rotary compressor using the piston in which the blade and the rotor unit are integrated as shown in the above embodiment, the compressor provided with the drive motor may be a rotary compressor in which the blade and the rotor unit are separate or It can also be applied to various other compressors.

The block diagram of the drive motor concerning this Embodiment and a compressor provided with the same. The AA sectional view taken on the line of the compressor of FIG. Sectional drawing of the drive motor of FIG. FIG. 2 is an enlarged view of the vicinity of an upstream inlet of an air gap of the drive motor of FIG. 1. The enlarged view of downstream exit vicinity of the air gap of the drive motor of FIG. 1 concerning the modification of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive motor 2 Motor rotor 3 Motor stator 4 Lower end plate (1st end plate)
5 Upper end plate (second end plate)
7 Gas passage 8 Rotor core 9 Laminated steel plate 10 Air gap 11 Magnet plate

Claims (6)

A rotor core (8) configured by laminating a plurality of laminated steel plates (9), and a pair of first end plates (4) and second end plates disposed at both ends of the rotor core (8) A rotor (2) having (5);
On the outer side in the radial direction of the rotor (2), a side peripheral surface of the rotor (2) is formed such that an air gap (10), which is a gap through which a gas fluid passes, is formed between the rotor (2). And a stator (3) arranged away from
Of the pair of end plates (4), (5), the outer diameter of the first end plate (4) located at least upstream of the gas fluid flowing through the air gap (10) is the same as that of the stator (3). Greater than the inner diameter,
Drive motor (1). From the protruding length A1 of the portion of the first end plate (4) protruding from the rotor core (8), the width B of the air gap (10), and the tip of the first end plate (4) The relationship between the distance C1 to the end face of the stator (3) is
A1 ≧ B, and
A1 ≧ (C1 / B) ² × B.
The drive motor (1) according to claim 1. The outer diameter of the second end plate (5) is not less than the outer diameter of the first end plate (4).
The drive motor (1) according to claim 1 or 2. From the protruding length A2 of the portion of the second end plate (5) protruding from the rotor core (8), the width B of the air gap (10), and the tip of the second end plate (5) The relationship between the distance C2 to the end face of the stator (3) is
A2 ≧ B, and
A2 ≧ (C2 / B) ² × B.
The drive motor (1) according to any one of claims 1 to 3. The compressor (101) provided with the drive motor (1) in any one of Claim 1 to 4. As the gas fluid, a refrigerant composed of carbon dioxide is used.
The compressor (101) according to claim 5.

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