JP2005184873A - Motor compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a permanent magnet rotating electric machine in which a stator core can be assembled by lamination in a die while solving the problem of noise. <P>SOLUTION: In the motor compressor containing a motor element and a compressor element being driven through a rotary shaft coupled with the motor element in a tubular frame becoming an enclosed container, the motor element comprises a stator having a stator core and a stator winding being fitted in the frame and supported, and a rotor supported rotatably on the inside of the stator while having permanent magnets wherein a protruding part abutting against the inner circumferential surface of the frame is provided on the outer circumferential part of the stator core and the outer circumferential area of the abutting part is set equal to several % or less of the entire inner circumferential area of the frame. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electric compressor constituting a cooling device provided in an air conditioner, a refrigerator, a freezer, a showcase or the like, and in particular, electric compression using a permanent magnet type rotating electric machine in which a permanent magnet is arranged on a rotor as an electric element. Related to the machine.

  Conventionally, in this type of permanent magnet type rotating electrical machine, concentrated winding is adopted for the stator winding, and rare earth neodymium permanent magnets are being adopted for the field magnets. There was a problem of increased noise. As a countermeasure against this noise, for example, in the electric compressor described in Japanese Patent Application Laid-Open No. 2001-34295 (Patent Document 1), the inner wall of the hermetic container of the compressor and the axial direction of the outer periphery of the stator core that contacts the inner wall are arranged. It has been proposed to cut out a portion.

JP 2001-342594 A

  In the above prior art, the outer peripheral shape of the outermost diameter of the stator core becomes two types, and by in-mold lamination using caulking (bonding of irregularities) by hack (HAC) using a hollow die (usually a progressive mold) When the stator core is formed, the stator core that contacts the inner wall of the pressure vessel can be stacked in the mold, but there is a problem that the stator core that does not contact does not have a reference position and cannot be stacked in the mold.

  The in-mold lamination is performed by stacking the outer periphery of the stator iron plate forming the stator core so that no positional deviation occurs with the reference position as the reference position.

  An object of the present invention is to provide an electric compressor which can be assembled by in-mold lamination of a stator core and can solve a noise problem.

  The present invention has a cylindrical frame serving as an airtight container, an electric element housed in the cylindrical frame, and a compression element housed in the cylindrical frame and driven by the electric element. A stator and a rotor that is rotatably disposed inside the stator and includes a permanent magnet, the stator being fitted into a cylindrical frame and supported; and the stator core The stator core has a large number of stacked stator iron plates, and the stator iron plate has a convex contact that abuts the inner peripheral surface of the cylindrical frame on the outer periphery. And the contact portion of each stator iron plate is continuous in the stacking direction.

  According to the present invention, the shape of the stator core is the same in the axial direction, and the abutment portion is provided on the outer periphery of the stator core. Therefore, the stator core can be assembled by in-mold lamination. In addition, an electric compressor with less noise can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. In each figure, the common code | symbol shows the same thing. Also, here, a 4-pole permanent magnet type rotating electrical machine is shown, and the ratio of the number of rotor poles to the number of stator slots is set to 2: 3.

  First, Embodiment 1 of the present invention will be described.

  1 shows an electric compressor according to Embodiment 1 of the present invention, showing an axial cross-sectional shape, and FIG. 2 shows a permanent magnet type rotating electrical machine according to Embodiment 1 of the present invention. The QQ radial direction cross-sectional shape is shown. The axial cross-sectional shape of the permanent magnet type rotating electrical machine that is the electric element shown in FIG. 1 is a POP sectional view of the permanent magnet type rotating electrical machine shown in FIG. FIG. 3 is a perspective view of the permanent magnet type rotating electric machine shown in FIG. FIG. 4 is a diagram showing a contact state of the stator iron plate in the frame.

  In FIG. 1, the external appearance of the electric compressor 1 is formed by a case. The case includes a cylindrical frame 2, an upper lid 3 on the upper end side, and a lower lid 4 on the lower end side. The frame 2 is a sealed container.

  The frame 2 houses an electric element 5 which is a permanent magnet type rotating electric machine and a compression element 6 called a scroll compressor.

  The frame 2 is formed by bending a plate-shaped steel plate into a cylindrical shape. The upper and lower ends of the frame 2 are closed with an upper lid 3 and a lower lid 4 to form a sealed container. The upper lid 3 and the lower lid 4 are welded to the frame 2 to form a sealed structure.

  The compression element 6 is formed by meshing a spiral wrap 9 standing upright on the end plate 8 of the fixed scroll member 7 and a spiral wrap 12 standing upright on the end plate 11 of the orbiting scroll member 10. A compression operation is performed by rotating the crank rotation shaft 13.

  Of the compression chambers 14 (14 a, 14 b,...) Formed by the fixed scroll member 7 and the orbiting scroll member 10, the compression chamber located on the outermost side is the scroll members 7, 10 with the orbiting motion. The volume gradually decreases. When the compression chambers 14 a and 14 b reach the vicinity of the centers of the scroll members 7 and 10, the compressed gas from the suction pipe 15 in both the compression chambers 14 is discharged from the discharge port 16 communicating with the compression chamber 14.

  The discharged compressed gas passes through gas passages (not shown) provided in the fixed scroll member 7 and the fixed member 17 and reaches the frame 2 below the fixed member 17, and a discharge pipe 18 provided on the side wall of the frame 2. To the outside of the electric compressor 1.

  Moreover, the electric element 5 which consists of a permanent magnet type rotary electric machine which comprises the electric compressor 1 is controlled by a separate inverter (not shown), and rotates at the rotational speed suitable for compression operation. Here, the electric element 5 made of a permanent magnet type rotating electric machine includes a stator 19 and a rotor 20 (not shown, but a balance weight is attached to both ends of the rotor 20). The upper side of the rotary shaft 13 provided in the rotor 20 is a crankshaft. An oil hole 21 is formed inside the rotary shaft 13, and the lubricating oil in the oil reservoir 22 at the lower portion of the frame 2 is rotated through the oil hole 21 by the rotation of the rotary shaft 13, and an upper bearing portion 23 of a sliding bearing type is provided. It is supplied to the lower bearing portion 24 of the ball bearing type. Reference numeral 25 denotes a terminal which supplies electric power from the inverter to the electric element 5. Reference numeral 26 denotes a pedestal.

The electric element 5 made of a permanent magnet type rotating electric machine shown in FIGS. 1 and 2 includes a stator 19 and a rotor 20, and the stator 19 includes a stator core 29 composed of teeth 27 and a core back 28, and teeth. In a slot 30 between 27, a concentrated-winding stator winding 31 wound around the teeth 27 (from a U-phase winding 31a, a V-phase winding 31b and a W-phase winding 31c of a three-phase winding). Composed of). A semicircular recess 32 is provided on the outer periphery of the stator core 29 where the teeth 27 are located.
Here, since the electric element 5 which is a permanent magnet type rotating electric machine has four poles and six slots, the slot pitch is 120 degrees in electrical angle. In the rotor 20, a permanent magnet insertion hole 34 is formed in the vicinity of the outer peripheral surface of the rotor core 33 having a rotation shaft hole 39 into which a rotation shaft (not shown) is inserted, and rare earth neodymium is formed in the permanent magnet insertion hole 34. The permanent magnet 35 made of is fixed. Reference numeral 36 denotes an outer periphery of the stator core 29, which is concentric with the rotating shaft.

  1, 2, and 3, reference numeral 37 denotes the outermost periphery of the stator core, and the diameter is set slightly larger than the outer periphery 36 of the stator core. In other words, the outer diameter 36 of the stator core has a small outer diameter, and the outer diameter 37 of the stator core has a large outer diameter.

  If the outer periphery 36 of the stator core is made too small, the magnetic characteristics of the permanent magnet type rotating electrical machine will be deteriorated. Therefore, the deviation between the diameters of 36 and 37 was set within 0.5 mm.

  Two protrusions 38 (convex contact portions) made of 38 a and 38 b are formed outside the outer periphery 36 of the stator core 29, and the outer peripheral surface of the protrusion 38 (convex contact portion) is the stator core 29. Is set so as to have the same diameter as the outermost periphery 37. Here, two protrusions 38 (convex contact portions) are provided on the outer periphery of each slot 30 (the outer periphery between the recesses 32), but one may be provided, and an arbitrary number may be provided. The height of the protrusion 38 (convex contact portion) is about 0.3 mm and the width is about 0.5 mm. The protrusions 38 (convex contact portions) are arranged so as to be continuous in the stacking direction in which the stator iron plates are stacked. The stator iron core is formed by laminating 0.35 mm or 0.5 mm electromagnetic steel plates (stator iron plates).

  Here, since the frame 2 is formed in a cylindrical shape by bending a plate-shaped steel plate, the accuracy of the circular diameter of the inner periphery is loose, and usually ± 100 μm in the diameter varies. As a result, the stator core 29 of the stator 19 that is shrink-fitted into the frame 2 cannot define where the inner periphery of the frame 2 is in contact with the outer periphery of the stator core 29. For this reason, the illustration of FIG. 1 shows the radial cross-sectional shape of the POP section of the permanent magnet type rotating electric machine of FIG. 2, but it is the stator core 29 that is in contact with the inner peripheral surface of the frame 2. It is a protrusion 38 (convex contact portion) on the outermost periphery 37, and the outer periphery 36 (small outer diameter) of the stator core is not in contact with the inner peripheral surface of the frame 2. For this reason, any stator iron plate constituting the stator core 29 comes into contact with (in contact with) the inner periphery of the frame 2. However, the outer peripheral surface area of the protrusion 38 (convex contact portion) is in contact with the inner peripheral surface area of the frame 2 only by 1%.

  In FIG. 4, two projections 38 ((convex contact portion)) formed on the outer periphery of the stator iron plate are provided on the inner peripheral side of the cylindrical frame 2 (usually thickness is 2.5 mm to 3.5 mm). The stator iron plate is supported by shrink fitting. By this shrink-fitting support, a space 40 is formed between the frame 2 and the outer periphery 36 and outermost periphery 37 of the stator core as shown in the outer peripheral shape 41 shown on the outer peripheral side of the stator iron plate. Is done.

  Further, the outer peripheral contact area of the protrusion 38 (convex contact portion) was set to 1% of the inner peripheral area of the frame 2 (including the axial length of the stator core). As a result, the vibration of the stator core 29 is hardly transmitted to the frame 2.

  FIG. 5 is a graph showing the noise measured for the electric compressor 1 described above. This electric compressor 1 has a nominal air conditioning capacity of 2.2 kW to 2.8 kW, and was operated by sealing R410A as a refrigerant. The measurement microphone was measured at a position in the center of the axial direction of the electric element 5 made of a permanent magnet type rotating electrical machine, separated by 1 m.

  FIG. 5 shows the measurement data of the conventional electric compressor and the electric compressor of the present invention together with the frequency component on the horizontal axis and the noise on the vertical axis. Note that the conventional electric compressor has no protrusion 38 (convex contact portion) on the outer periphery of the fixed iron core 29, and the outer periphery 36 of the stator iron core 33 extends uniformly in the stacking direction (axial direction). The thing in contact was used.

  As shown in FIG. 5, the noise of the electric compressor 1 of the present invention is slightly higher than that of the conventional components for 200 Hz, 400 Hz, 8 kHz, and 10 kHz components, but the electric components of the present invention are used for other frequency components. The noise of the compressor 1 is significantly smaller than before. FIG. 6 shows the overall (OA) value of noise. As shown in FIG. 6, the noise of the electric compressor 1 according to the present invention is significantly reduced to 10.4 dB compared to the prior art.

  This noise reduction is the same in the stacking direction (axial direction) of the stator core 29, and the contact (contact) area with the inner peripheral surface of the frame in the circumferential direction is the total area of the inner periphery of the frame (the axial length of the stator core 29). This is because the vibration of the stator core 29 is difficult to be transmitted to the frame 2 due to the 1% contact. Since the contact area of the protrusion 38 (convex contact part) of the contact part does not change to noise even if it is originally 57.5% to 28.75%, the contact area should be several%. Smaller is desirable. The contact portion will be described from the aspect of assembling the stator core 29.

  The stator iron core 29 is formed by laminating stator iron plates punched by a press. This lamination is performed in a lamination die called a hollow die (commonly referred to as a progressive die). The stator iron plate corresponding to the outermost periphery 37 (large outer diameter) of the stator core 29 has an outer diameter that matches the inner diameter of the laminated mold. Are laminated in a state of being well aligned in the laminating direction (axial direction).

  Therefore, it is possible to provide a stator core that is low in noise and that can be laminated using a laminated die called a hollow die.

  In addition, the stator iron plates stacked in the mold are made into a strong bonded body (stator core) by caulking with HAC (uneven connection). The stator 19 made by winding the stator winding 31 around the stator core 29 is fixed in the frame 2 by shrink fitting.

  Next, a second embodiment of the present invention will be described.

  FIG. 7 shows an electric compressor 1 according to Embodiment 2 of the present invention. FIG. 7 shows a cross-sectional shape similar to that shown in FIG. 1, except that a through hole 44 is provided in a part of the frame 2. The through hole 44 is provided at a position where the projection 38 (convex contact portion) is located. Through this through hole 44, the protrusion 38 (convex contact portion) of the stator 19 and the frame 2 were fixed by tack welding.

  The outer diameter of the stator 19 of the permanent magnet type rotating electric machine used in the electric compressor 1 of the present invention is 105 mm and the thickness is 45 mm. The compressor has a drop test, and if the stator 19 is displaced from the shrink-fitting position of the frame 2 due to an impact at the time of dropping, the standard is not satisfied. For this reason, a through hole 44 is provided in a part of the frame 2, and the protrusion 38 (convex contact portion) of the stator 19 and the frame 2 are tack-welded through the through hole 44. It is fixed. Thereby, the electric compressor 1 which can endure a drop test can be provided.

  Next, Embodiment 3 of the present invention will be described.

  FIG. 8 shows an electric compressor 1 according to a third embodiment of the present invention. FIG. 8 shows a cross-sectional shape similar to that shown in FIG. 1 except that a fall prevention material 42 is provided at the lower part of the stator 19 on the inner periphery of the frame 2.

  A ring-shaped fall prevention material 42 is shrink-fitted on the frame 2, and then the stator 29 is shrink-fitted on top of the fall prevention material 42. The lower part of the protrusion 38 (convex contact part) is received by being received by the fall prevention member 42.

  Thereby, even if a drop test is performed, the stator 19 is not displaced from the shrink fit position, and the electric compressor 1 that can withstand the drop test can be provided.

  Next, a fourth embodiment of the present invention will be described.

  FIG. 9 shows an electric compressor 1 according to Embodiment 4 of the present invention. FIG. 9 shows a cross-sectional shape similar to that shown in FIG. 1 except that a fall prevention member 45 is provided at the lower part of the stator 19 on the inner periphery of the frame 2, and a through hole 44 is formed in a part of the frame 2. And the frame 2 and the fall prevention member 45 are fixed by tack welding through the through hole 44.

  First, after the ring-shaped fall prevention material 45 is shrink-fitted into the frame 2, a through hole 44 is provided in a part of the frame 2, and the fall prevention material 45 and the frame 2 are tack-welded through the through hole 44, The stator 29 is fixed at the welded portion 43, and then the stator 29 is shrink-fitted onto the top of the fall prevention member 45. Thereby, even if a drop test is performed, the stator 19 is not displaced from the shrink fit position, and the electric compressor 1 that can withstand the drop test can be provided. In addition, the fall prevention material 45 shortens the axial direction length from the fall prevention material 42 in order to reduce the material used, and tack welding is used together in order to ensure the drop strength.

  Next, a fifth embodiment of the present invention will be described.

  FIG. 10 shows an electric compressor 1 according to a fifth embodiment of the present invention. FIG. 11 (a) is a sectional view taken along the line BB in FIG. 10, and FIG. 11 (b) is a direction taken along the line AA in FIG. A cross-sectional view is shown. FIG. 11A is the same as FIG.

  As apparent from the outer peripheral shape 41 of the stator iron plate shown in FIG. 11B, six divided outer peripheries are formed between the semicircular recesses 32 on the outer periphery of the stator iron plate. The projections 38 (convex contact portions) are not provided on the three divided outer peripheries, and the projections 38 (convex contact portions) are not provided on the remaining three outer peripheries. It is configured such that the places where the protrusions 38 (convex contact portions) are provided and the places where the protrusions 38 (convex contact portions) are not provided are alternately arranged. The stator core outer periphery 36 where the protrusions 38 (convex contact portions) are provided is the same as the stator core outermost periphery 37. The protrusions 38 (convex contact portions) are continuous in the stacking direction. In FIG. 11A, projections 38 (convex contact portions) are provided on the entire outer periphery of the division.

  10 shows a cross-sectional shape similar to that shown in FIG. 1, except that most of the shape of the stator core 29 on the inner periphery of the frame 2 is the shape shown in FIG. A part of the central portion of the iron core 29 has a shape shown in FIG. That is, there are two types of stator iron plates of the stator core 29. One type of stator iron plate has protrusions 38 (convex contact portions) on any divided outer periphery. Another type of stator iron plate has a portion where there is no projection 38 (convex contact portion) due to the divided outer periphery. The protrusion 38 (convex contact portion) may be continuous in the stacking direction and may not be continuous.

  Thereby, since there is a portion where the inner periphery of the frame 2 and the stator core 29 are shrink-fitted and fixed, the stator 19 is not displaced from the shrink-fitting position even if a drop test is performed, and tack welding is not required. The electric compressor 1 that can withstand the drop test can be provided. In addition, although the noise reduction effect falls from FIG. 1, the noise reduction effect can be ensured conventionally.

  In addition, it goes without saying that a slight noise reduction effect can be obtained even if only the shape of FIG.

  Here, the compressors shown in FIGS. 1, 7, 8, 9, and 10 are called scroll compressors, and the compression element is arranged in the upper part and the electric element is arranged in the lower part. Apart from this, there is a rotary compressor having a structure in which the electric element is on the upper side and the compression element is on the lower side. This rotary compressor has a structure without a bearing on the upper side. This is to reduce the manufacturing cost. The electric compressor of the present invention can also be applied to this rotary compressor.

The electric compressor which concerns on Embodiment 1 of this invention, and is sectional drawing which shows an axial direction cross-sectional shape. The permanent magnet rotary electric machine which concerns on Embodiment 1 of this invention is shown, and the figure which shows the QQ radial direction cross-sectional shape of FIG. 1 is a perspective view of a permanent magnet type rotating electrical machine according to Embodiment 1 of the present invention. The figure which shows the stator iron plate contact condition in the flame | frame which concerns on Embodiment 1 of this invention. The figure which shows the noise measurement result of the electric compressor carrying a permanent-magnet-type rotary electric machine. The figure which shows the overall (OA) value of the noise of the electric compressor carrying the permanent magnet type rotary electric machine which concerns on Embodiment 1 of this invention. Sectional drawing which shows the axial direction cross-sectional shape of the electric compressor 1 which concerns on Embodiment 2 of this invention. Sectional drawing which shows the axial direction cross-sectional shape of the electric compressor 1 which concerns on Embodiment 3 of this invention. Sectional drawing which shows the axial direction cross-sectional shape of the electric compressor 1 which concerns on Embodiment 4 of this invention. Sectional drawing which shows the axial direction cross-sectional shape of the electric compressor 1 which concerns on Embodiment 5 of this invention. The figure which shows the stator iron plate contact condition in the flame | frame which concerns on Embodiment 5 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Electric compressor, 2 ... Frame, 3 ... Upper lid, 4 ... Lower lid, 5 ... Electric element (permanent magnet type rotary electric machine), 6 ... Compression element (scroll compressor), 7 ... Fixed scroll member, 8 ... End Plate 9, spiral wrap, 10, orbiting scroll member, 11, end plate, 12, spiral wrap, 13 crank shaft, 14 compression chamber, 15 suction pipe, 16 discharge port, 17 fixing member 18 ... Discharge pipe, 19 ... Stator, 20 ... Rotor, 21 ... Oil hole, 22 ... Oil sump, 23 ... Upper bearing, 24 ... Lower bearing, 25 ... Terminal, 26 ... Base, 27 ... Teeth, 28 ... Core back, 29 ... Stator core, 30 ... Slot, 31 ... Stator winding, 32 ... Recess, 33 ... Rotor core, 34 ... Permanent magnet insertion hole, 35 ... Permanent magnet, 36 ... Stator Iron core outer periphery, 37 ... Stator iron core outermost periphery, 38 ... Protrusions, 9 ... rotor shaft hole 40 ... space, 41 ... core peripheral shape, 42 ... fall prevention member, 43 ... welding section, 44 ... through hole, 45 ... fall prevention member.

Claims (10)

A cylindrical frame serving as a sealed container; an electric element housed in the cylindrical frame; and a compression element housed in the cylindrical frame and driven by the electric element;
The electric element has a stator and a rotor that is rotatably disposed inside the stator and has a permanent magnet.
The stator has a stator core fitted and supported in the cylindrical frame, and a stator winding wound around the stator core,
The stator core has a number of stacked stator iron plates,
The stator iron plate has a convex contact portion that contacts the inner peripheral surface of the cylindrical frame on the outer periphery, and the contact portions of the stator iron plates are continuous in the stacking direction. Compressor. The electric compressor according to claim 1,
The electric compressor according to claim 1, wherein a ratio of an outer peripheral area of the contact portion and an entire inner peripheral area of the cylindrical frame is several percent or less. The electric compressor according to claim 1,
An electric compressor characterized in that a through hole penetrating the cylindrical frame is provided at a position where the contact portion is located, and the frame and the contact portion are fixed by welding at the through hole. The electric compressor according to claim 1,
An electric compressor characterized in that a fall prevention material with which the lower part of the abutting portion hits is formed on the inner periphery of the cylindrical frame. In the electric compressor according to claim 4,
An electric compressor characterized in that a through hole is provided in a part of the cylindrical frame, and the frame and the fall prevention material are fixed by welding at the through hole. The electric compressor according to claim 1,
An electric compressor, wherein the laminated stator iron plates are swaged together to form a stator iron core, and the stator iron core is shrink-fitted to the frame. A cylindrical frame serving as a sealed container; an electric element housed in the cylindrical frame; and a compression element housed in the cylindrical frame and driven by the electric element;
The electric element has a stator and a rotor that is rotatably disposed inside the stator and has a permanent magnet.
The stator has a stator core fitted and supported in the cylindrical frame, and a stator winding wound around the stator core,
The stator core has a number of stacked stator iron plates,
Providing a plurality of recesses on the outer periphery of the stator iron plate,
On the divided outer periphery of the stator iron plate divided by the recess, a place where a convex contact portion that contacts the inner peripheral surface of the cylindrical frame is formed and a place not formed are provided, and each stator iron plate An electric compressor characterized in that the abutting portions are continuous in the stacking direction. A cylindrical frame serving as a sealed container; an electric element housed in the cylindrical frame; and a compression element housed in the cylindrical frame and driven by the electric element;
The electric element has a stator and a rotor that is rotatably disposed inside the stator and has a permanent magnet.
The stator has a stator core fitted and supported in the cylindrical frame, and a stator winding wound around the stator core,
The stator core has a number of stacked stator iron plates,
Providing a plurality of recesses on the outer periphery of the stator iron plate,
At least two types of the stator iron plate having a divided outer periphery divided by the recess,
One has a convex contact portion that contacts the inner peripheral surface of the cylindrical frame on any of the divided outer periphery,
The other is where there is a portion where the convex abutment portion is present due to the divided outer periphery,
The electric compressor characterized in that the contact portions of the stator iron plates are continuous in the stacking direction. The electric compressor according to claim 1,
The electric compressor, wherein the stator winding is wound around the teeth of the stator core in a concentrated manner. The electric compressor according to claim 1,
The electric compressor is characterized in that the compression element is a scroll compressor, the compression element is arranged at the upper part, and the electric element is arranged at the lower part.

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