JP2008014320A - Electric compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the axial dimension of an electric compressor by positioning at least a part of a compressor mechanism part in a stator. <P>SOLUTION: In this electric compressor, a crank part 125a and both bearings 126, 127 are positioned in a coil end part 112a, and a thrust receiving surface 112a and a pin 137a (rotation preventing mechanism 137) are positioned outside the stator 123. Consequently, the axial dimension of the electric compressor 100 can be reduced while preventing the thrust receiving surface 112a and the pin 137a (rotation preventing mechanism 137) from being damaged. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric compressor in which an electric motor that obtains electric power and generates torque and a compressor that sucks and compresses fluid, and is a supercritical refrigeration cycle in which the pressure on the high-pressure side exceeds the critical pressure of the refrigerant It is effective for use.

The structure of the electric compressor is, for example, as described in Patent Document 1, from an electric motor unit configured with a stator and a rotor, and a position shifted in the axial direction from the electric motor unit (rotor). A movable part such as a movable scroll that is movable by obtaining a driving force, and a compression mechanism part that includes a fixed part such as a fixed scroll fixed to the housing are provided.
JP-A-9-112458

By the way, in recent years, as one of countermeasures against defluorocarbons, supercritical pressure in which the pressure on the high pressure side exceeds the critical pressure of the refrigerant, such as a refrigeration cycle using carbon dioxide (CO ₂ ) as a refrigerant (hereinafter referred to as CO ₂ cycle). The refrigeration cycle is being researched. In the CO ₂ cycle, the volume flow rate of the refrigerant circulating in the refrigeration cycle is smaller than that of a conventional refrigeration cycle using chlorofluorocarbon as a refrigerant (hereinafter referred to as a normal refrigeration cycle). The inventors have found that the (discharge volume) can be reduced and the compression mechanism can be miniaturized.

  On the other hand, since the pressure on the high-pressure side becomes higher than that in the normal refrigeration cycle and the torque for driving the compression mechanism (movable part) must be increased, there is a high risk of increasing the size of the electric motor unit. An object of the present invention is to reduce the size of an electric compressor in which an electric motor unit and a compression mechanism are integrated.

  In order to achieve the above object, the present invention uses the following technical means. The inventions according to claims 1 to 8 are characterized in that at least a part of the compression mechanism (130) is located in the stator (123). As a result, as described in the above publication, the axial direction of the electric compressor (rotor shaft (125) direction) is higher than that of the electric compressor in which the compression mechanism portion is disposed at a position shifted in the axial direction from the electric motor portion. The dimensions can be reduced.

In addition, as described in claim 3, by positioning the crank portion (125a) in the stator (123), the movable portion (131) and the crank portion (125a) which are part of the compression mechanism portion (130) are provided. May be positioned in the stator (123). By the way, in the supercritical refrigeration cycle such as the CO ₂ cycle, as described above, the discharge capacity (discharge volume) of the compression mechanism section (130) can be reduced, so that a rotation prevention mechanism (137) and a thrust receiving section, which will be described later, are provided. The inventors discovered that the entire compression mechanism (130) including (112a) can be disposed in the stator (123).

However, since the compression reaction force increases as the pressure on the high-pressure side increases, the thrust force (F _S ) received by the thrust receiving portion (112a) and the force (torque) that the movable portion (131) tries to rotate. ), The force (F _R ) received by the rotation prevention mechanism (137) also increases, and the thrust receiving portion (112a) and the rotation prevention mechanism (137) may be damaged.

Therefore, in the invention according to claim 4, thrust receiving portion for receiving a thrust force in a direction parallel to the rotor shaft (125) of the compression reaction force acting on the movable portion (131) to _{(F S)} to (112a), It is located outside the stator (123). Thereby, since the area of the thrust receiving part (112a) can be expanded, the stress generated in the thrust receiving part (112a) can be reduced, and the thrust receiving part (112a) can be prevented from being damaged.

The invention according to claim 5 is characterized in that the anti-rotation mechanism (137) for preventing the movable portion (131) from rotating around the crank portion (125a) is positioned outside the stator (123). And Thereby, since the distance from the crank part (125a) to the rotation prevention mechanism (137) can be increased, the force (F _R ) received by the rotation prevention mechanism (137) can be reduced, and the rotation prevention mechanism ( 137) can be prevented from being damaged.

  The invention according to claim 6 is characterized in that the rotor shaft (125) is rotatably supported via a bearing (126) disposed on the outer peripheral surface of the balancer ring (128). Thereby, compared with the case where the bearing (126) directly supports the rotor shaft (125), the axial dimension can be reduced by at least the thickness of the bearing (128).

  The invention according to claim 7 is characterized in that the bearings (126, 127) for rotatably supporting the rotor shaft (125) are located in the stator (123). Thereby, the axial direction dimension of a rotor shaft (125) among the physiques of an electric compressor can be made still smaller.

  The invention according to claims 9 to 11 includes first and second bearings (126a, 127a) that rotatably support the rotor (124), and at least the compression mechanism (130) of the both bearings (126a, 127a). The first bearing (126a) on the side is located in the stator (123). Thereby, the dimension of the axial direction (rotor shaft (125) direction) of an electric compressor can be made small similarly to the invention of Claims 1-8.

  As described in claim 10, the first bearing (126a) is preferably a needle roller bearing. Further, as described in claim 11, the second bearing (127a) is preferably a radial bearing capable of receiving a thrust load. Incidentally, the reference numerals in parentheses of the above means indicate the correspondence with the specific means described in the embodiments described later.

(First Embodiment) In this embodiment, the electric compressor 100 according to the present invention is applied to a compressor for a CO ₂ cycle, and FIG. 1 shows the axial direction of the electric compressor 100 according to the present embodiment. It is sectional drawing.

In FIG. 1, reference numeral 111 denotes a substantially cup-shaped first housing that houses an electric motor unit 120 described later, 112 denotes a second housing that covers the opening side of the first housing 111, and both the housings 111 and 112 are made of an aluminum die. It is a cast. Hereinafter, the housings 111 and 112 are collectively referred to as the housing 110. In addition, an AC electric motor unit (hereinafter abbreviated as a motor) 120 that generates torque by AC power is configured in the housing 110, and a CO 2 is disposed on the opposite side of the second housing 112 from the CO 120. ₂ A scroll type compression mechanism section (hereinafter abbreviated as a compression mechanism) 130 for sucking and compressing (fluid) is configured.

  Next, the motor 120 will be described. Reference numeral 121 denotes a stator core (yoke) made of a magnetic material such as a silicon steel plate fixed to the housing 110, and 122 denotes a winding (coil) wound around the stator core 121. A stator 123 is composed of the wire 122, the stator core 121, and the like.

  Reference numeral 124 denotes a rotor that has a plurality of permanent magnets and rotates within the stator 123. Reference numeral 125 denotes a rotor shaft that supports the rotor 124. The rotor shaft 125 is rotatably supported in the housing 110 via bearings 126 and 127. Next, the compression mechanism 130 will be described.

  Reference numeral 131 denotes a movable scroll (movable portion) that is rotationally driven by the rotor 124. As is well known, the movable scroll 131 has a substantially disc-shaped end plate portion 131a and a spiral scroll tooth portion protruding from the end plate portion 131a. 131a. The movable scroll 131 has a shell-type (eccentric part) 125a formed on one end side (the right side of the paper) of the rotor shaft 125 at a boss part 131c formed substantially at the center of the end board part 131a. It is connected via a needle roller bearing (needle bearing) 125b of a type having no inner ring.

The crank portion 125a is formed at a position that is eccentric to the radially outward side from the rotation center of the rotor shaft 125. Reference numeral 132 denotes a fixed scroll (shell) fixed to the housing 110 (second housing 112). The fixed scroll 132 is engaged with the scroll teeth 131b of the movable scroll 131 and sucks and compresses CO _2. spiral scroll teeth 132a constituting the chamber V _C is formed.

Also, 133 is a discharge chamber for smoothing the refrigerant discharged from the working chamber V _C, the discharge chamber 133 is formed by the fixed crawling 132 and rear housing 134. Incidentally, 135 is a reed valve-like discharge valve to prevent the CO ₂ from flowing back from the discharge chamber 133 to the working chamber V _C side, 136 is a stopper for restricting the maximum opening degree of the discharge valve 135.

  Reference numeral 137 denotes a known anti-rotation mechanism that prevents the movable scroll 131 from rotating around the crank portion 125a. The anti-rotation mechanism 137 includes a pin 137a press-fitted into the fixed scroll 132 and the movable scroll 131 (end). It has a through hole 137b formed in the board portion 131a) and through which the pin 137a is inserted. For this reason, the movable scroll 131 revolves around the rotor shaft 125 without rotating with the rotation of the rotor shaft 125.

  In this embodiment, a collar 137c that prevents the outer peripheral surface of the pin 137a and the inner peripheral surface of the through hole 137b from directly contacting and sliding is press-fitted into the through hole 137b. As is clear from FIG. 1, in this embodiment, the crank portion 125 a and the both bearings 126 and 127 are located in the coil end portion 112 a of the stator 123, while the rotation prevention mechanism 137 is outside the stator 123. positioned.

  The coil end portion 112a is a position of the stator 123 that is shifted from the stator core portion 121 toward the axial end portion of the rotor shaft 125 (the portion of the winding 122 that protrudes from the stator core portion 121). To tell. Incidentally, reference numeral 128 denotes an annular balancer ring that cancels centrifugal force acting on the rotor shaft 125 by rotating integrally with the rotor shaft 125 when the movable scroll 131 revolves. The rotor shaft 125 is rotatably supported while being disposed on the outer peripheral surface.

Further, the thrust force F _S in the direction parallel with the rotor shaft 125 of the compression reaction force acting on the movable crawl 131, the contact surface of the movable scroll 131 of the second housing 112 (hereinafter, the thrust bearing surface of the contact surface The thrust receiving surface 112a (thrust receiving portion) is located outside the stator 123, like the rotation prevention mechanism 137.

Therefore, when the movable scroll 131 revolves, the movable scroll 131 to slide while contacting the thrust bearing surface 112a, receives a force (reaction) against the thrust receiving surface 112a (second housing 12) to the thrust force _{F S} It will be. Next, features of the present embodiment will be described. According to the present embodiment, the connecting portion (boss portion 131c) with the crank portion 125a, which is a part of the movable scroll 131, and both bearings 126, 127 are positioned in the portion corresponding to the coil end portion 112a in the stator 132. Therefore, as described in the above publication, the axial direction of the electric compressor 100 (in the direction of the rotor shaft 125) compared to the electric compressor in which the compression mechanism portion is disposed at a position shifted in the axial direction from the electric motor portion. The dimension of can be reduced.

  Further, in the present embodiment, the bearing 126 rotatably supports the rotor shaft 125 while being disposed on the outer peripheral surface of the balancer ring 128, so that the bearing 126 directly supports the rotor shaft 125 compared to the case where the bearing 126 directly supports the rotor shaft 125. Thus, the axial dimension can be reduced by at least the thickness t of the bearing 128 (see FIG. 1). Moreover, since the bearing 125 is located in the part corresponding to the coil end part 112a in the stator 123, the axial direction dimension of the electric compressor 100 can be made small.

By the way, in the supercritical refrigeration cycle such as the CO ₂ cycle, as described above, the discharge capacity (discharge volume) of the compression mechanism 130 can be reduced. Therefore, the compression mechanism including the rotation prevention mechanism 137 and the thrust receiving surface 112a is also included. The inventors have discovered that the entire 130 can be disposed within the coil end 122a. However, since the compression reaction force increases as the pressure on the high-pressure side increases, the pin is opposed to the thrust force F _S received by the thrust receiving surface 112a and the force (torque) that the movable scroll 131 tries to rotate. 137a is the radial force applied in the radial direction (shearing force) _{F R} increases.

Therefore, when the entire compression mechanism 130 including the rotation prevention mechanism 137 and the thrust receiving surface 112a is disposed in the coil end 122a, the area of the thrust receiving surface 112a is reduced, and the surface pressure (stress) of the thrust receiving surface 112a is reduced. and the radial force _{F R} the distance from the crank portion 125a until the pin 137a is reduced pin 137a receives and ends up excessively increased, there is a possibility that the thrust receiving surface 112a and the pin 137a (rotation preventing mechanism 137) is damaged .

On the other hand, in this embodiment, since the thrust receiving surface 112a and the pin 137a (spinning prevention mechanism 137) are located outside the stator 123, the area of the thrust receiving surface 112a and the distance from the crank portion 125a to the pin 137a. The distance can be expanded. Therefore, it is possible to reduce the radial force _{F R} received by the surface pressure (stress) and the pin 137a of the thrust receiving surface 112a, it is possible to prevent the thrust receiving surface 112a and the pin 137a (rotation preventing mechanism 137) is damaged.

  By the way, in the electric compressor 100 applied to the supercritical refrigeration cycle, since the driving torque of the compression mechanism 130 is increased, the physique of the motor 120 must be larger than that of the electric compressor applied to the normal refrigeration cycle. I don't get it. Therefore, in the present embodiment, the diameter of the motor 120 is increased to such an extent that the crank portion 125a (the boss portion 131c) and the both bearings 126 and 127 can be disposed in the coil end portion 112a. In addition, the crank portion 125a (boss portion 131c) and the both bearings 126 and 127 are disposed in the coil end portion 112a, so that the axial dimension of the electric compressor 100 is reduced.

  That is, in the electric compressor 100 according to the present embodiment, the physique of the electric compressor 10 is more than necessary by disposing the crank portion 125a (boss portion 131c) and the both bearings 126 and 127 in the coil end portion 112a. It is possible to increase the torque of the motor 120 while preventing the expansion.

  (Second Embodiment) FIG. 2 is a sectional view of an electric compressor 100 according to a second embodiment. In this embodiment, of the first and second bearings 126a and 127a that rotatably support the rotor shaft 125 (rotor 124), the first bearing 126a on the compression mechanism 130 side is a shell-type needle roller bearing. At the same time, the first bearing 126a is positioned in the coil end portion 122a. On the other hand, the second bearing 127a located on the opposite side of the compression mechanism 130 across the rotor 124 is a radial ball bearing.

In the present embodiment, the first bearing 126 a directly supports the rotor shaft 125 without using the balancer ring 128, and the second bearing 127 a is press-fitted and fixed to the first housing 111. Incidentally, in this embodiment, a bushing 125c that allows the movable scroll 131 to be slightly displaced with respect to the crank portion 125a is disposed between the crank portion 125a and the bearing 125b. Therefore, when the movable scroll 131 is pivoted, the scrolls tooth portion 131b by a compression reaction force acting on the movable scroll 131, since the increasing contact pressure 132a, thereby improving the sealing of the working chamber V _C.

  Further, a stepped portion 125d is formed on the rotor shaft 125 on the second bearing 127a side, and the stepped portion 125d causes the rotor shaft 125 (rotor 124) to move to the second bearing 127a side (the left side in the drawing). It is restricted to move toward. On the other hand, the movement of the rotor shaft 125 (rotor 124) toward the first bearing 126a side (the right side in the drawing) means that the C-type retaining ring disposed on the opposite side of the stepped portion 125d across the second bearing 127a. It is regulated by 125e.

  By the way, in the present embodiment, the magnetization of the rotor 124 (permanent magnet thereof) is performed by energizing the stator 123 with the rotor 124 assembled in the stator 123. For this reason, in this embodiment, when magnetizing the rotor 124, a hole 111 a for inspecting whether the rotor 124 is located at a predetermined position with respect to the stator 123 is formed in the first housing 111. Has been.

  Therefore, in this embodiment, the C-type retaining ring 125e is inserted and assembled from the hole 111a, and after the C-type retaining ring 125e is assembled, the hole 111b is closed by the plug 111b. The internal thread 111c formed in the plug 111b is for inserting a jig when the plug 111b is pulled out. Next, features of the present embodiment will be described.

  According to this embodiment, since the first bearing 126a is located in the coil end portion 122a (stator 123), the axial dimension of the electric compressor 100 can be reduced as in the first embodiment. . In addition, since the first bearing 126a is a needle bearing, the outer diameter of the bearing is smaller than that of a normal radial ball bearing or the like. Therefore, the first bearing 126a can be easily positioned in the coil end portion 122a (stator 123) without increasing the outer diameter of the stator 123.

By the way, the thrust force F _{S in the} direction parallel to the rotor shaft 125 out of the compression reaction force acting on the movable crawl 131 is received by the rotor 124 even though it is received by the thrust receiving surface 112a as in the first embodiment. Thrust load is applied. At this time, since the first bearing 126a is a needle bearing, generally it cannot receive a thrust load.

  However, in the present embodiment, since the second bearing 127a is a radial ball bearing, it can receive a certain amount of thrust load although it is smaller than the thrust bearing. Therefore, even if the first bearing 126a is a needle bearing, there is no problem in the rotational movement of the rotor 124. By the way, in the above-mentioned embodiment, although the scroll type compression mechanism part was employ | adopted, this invention is not limited to this, Also with respect to the electric compressor which has other compression mechanism parts, such as a vane type compression mechanism part. Applicable.

  Moreover, the application of the electric compressor 100 according to the present invention is not limited to the supercritical refrigeration cycle, and can be applied to a normal refrigeration cycle and other uses. In the second embodiment, the second bearing 127a located on the opposite side of the compression mechanism 130 across the rotor 124 is a radial ball bearing. However, the second embodiment is not limited to this, and the conical shape Any radial bearing that can receive other thrust loads such as a roller bearing may be used.

  In the second embodiment, the first bearing 126a is a shell-type needle bearing, but the second embodiment is not limited to this, and may be another bearing.

It is sectional drawing of the electric compressor which concerns on 1st Embodiment of this invention. It is sectional drawing of the electric compressor which concerns on 2nd Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 110 ... Housing, 120 ... AC electric motor part, 121 ... Stator core part, 122 ... Winding, 123 ... Stator, 124 ... Rotor, 130 ... Compression mechanism part, 131 ... Movable scroll (movable part), 132 ... Fixed scroll (Fixed part) 137 ... Anti-rotation mechanism, 112a ... Thrust receiving surface (thrust receiving part).

Claims (11)

A housing (110);
An electric motor portion (120) provided in the housing (10) and including a stator (123) fixed to the housing (110), and a rotor (124) rotating in the stator (123);
A movable portion (131) driven to rotate by the rotor (124), and a fixed portion (132) fixed to the housing (110), and a compression mechanism portion (130) for sucking and compressing fluid. And
The electric compressor characterized in that at least a part of the compression mechanism (130) is located in the stator (123). A housing (110);
A stator (123) provided in the housing (10) and having a stator core (121) fixed to the housing (110) and a winding (122) wound around the stator core (121); And an electric motor unit (120) including a rotor (124) rotating in the stator (123);
A movable portion (131) driven to rotate by the rotor (124), and a fixed portion (132) fixed to the housing (110), and a compression mechanism portion (130) for sucking and compressing fluid. And
At least a part of the compression mechanism part (130) corresponds to a coil end part (122a) protruding in the axial direction of the rotor (124) from the stator core (121) in the stator (123). The electric compressor characterized by being located in. On one end side of the rotor shaft (125) that supports the rotor (124), a crank portion (125a) is provided at a position eccentric from the center of rotation to the radially outward side,
The movable part (131) is rotatably connected to the crank part (125a) and revolves around the rotor shaft (125) along with the rotation of the rotor shaft (125),
Furthermore, the said crank part (125a) is located in the said stator (123), The electric compressor of Claim 1 or 2 characterized by the above-mentioned. A housing (110);
An electric motor portion (120) provided in the housing (10) and including a stator (123) fixed to the housing (110), and a rotor (124) rotating in the stator (123);
A scroll-type compression mechanism (130) having a movable scroll (131) driven to rotate by the rotor (124) and a fixed scroll (132) fixed to the housing (110) and sucking and compressing fluid; Comprising
On one end side of the rotor shaft (125) that supports the rotor (124), a crank portion (125a) is provided at a position eccentric from the center of rotation to the radially outward side,
The movable scroll (131) is rotatably connected to the crank portion (125a) and revolves around the rotor shaft (125) along with the rotation of the rotor shaft (125),
A thrust receiving portion (112a) for receiving a thrust force (F _S ) in a direction parallel to the rotor shaft (125) out of the compression reaction force acting on the movable scroll (131) is provided,
The crank part (125a) is located in the stator (123),
The electric compressor according to claim 1, wherein the thrust receiving portion (112a) is located outside the stator (123). A housing (110);
An electric motor unit (120) including a stator (123) provided in the housing (10) and fixed to the housing (110), and a rotor (124) rotating in the stator (123);
A scroll-type compression mechanism (130) having a movable scroll (131) rotated by the rotor (124) and a fixed scroll (132) fixed to the housing (110) and sucking and compressing fluid; Comprising
On one end side of the rotor shaft (125) that supports the rotor (124), a crank portion (125a) is provided at a position eccentric to the radially outward side from the rotation center thereof,
The movable scroll (131) is rotatably connected to the crank portion (125a) and revolves around the rotor shaft (125) along with the rotation of the rotor shaft (125).
A rotation preventing mechanism (137) for preventing the movable scroll (131) from rotating around the crank portion (125a) is provided;
The crank part (125a) is located in the stator (123),
The electric compressor according to claim 1, wherein the rotation prevention mechanism (137) is located outside the stator (123). When the movable scroll (131) revolves around the rotor shaft (125), the rotor shaft (125) has an annular balancer ring (128) that cancels centrifugal force acting on the rotor shaft (125). Is provided,
The electric motor according to claim 4 or 5, wherein the rotor shaft (125) is rotatably supported via a bearing (126) disposed on an outer peripheral surface of the balancer ring (128). Compressor. A housing (110);
An electric motor portion (120) provided in the housing (10) and including a stator (123) fixed to the housing (110), and a rotor (124) rotating in the stator (123);
A compression mechanism (130) that has a movable part (131) that is rotationally driven by the rotor (124), and a fixed part (132) that is fixed to the housing (110), and that sucks and compresses fluid;
Bearings (126, 127) for rotatably supporting the rotor (124),
At least a part of the compression mechanism (130) is located in the stator (123),
Furthermore, the said bearing (126, 127) is located in the said stator (123), The electric compressor characterized by the above-mentioned. An electric compressor applied to a supercritical refrigeration cycle in which the pressure on the high pressure side exceeds the critical pressure of the refrigerant,
A housing (110);
An electric motor portion (120) provided in the housing (10) and including a stator (123) fixed to the housing (110), and a rotor (124) rotating in the stator (123);
A movable portion (131) driven to rotate by the rotor (124), and a fixed portion (132) fixed to the housing (110), and a compression mechanism portion (130) for sucking and compressing fluid. And
The electric compressor characterized in that at least a part of the compression mechanism (130) is located in the stator (123). A housing (110);
An electric motor portion (120) provided in the housing (10) and including a stator (123) fixed to the housing (110), and a rotor (124) rotating in the stator (123);
A compression mechanism (130) that has a movable part (131) that is rotationally driven by the rotor (124), and a fixed part (132) that is fixed to the housing (110), and that sucks and compresses fluid;
First and second bearings (126a, 127a) for rotatably supporting the rotor (124),
Of the two bearings (126a, 127a), at least the first bearing (126a) on the compression mechanism (130) side is positioned in the stator (123).   The electric compressor according to claim 9, wherein the first bearing (126a) is a needle roller bearing.   The electric compressor according to claim 10, wherein the second bearing (127b) is a radial bearing capable of receiving an axial thrust load acting on the rotor (124).

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