KR101970529B1 - Motor operated compressor - Google Patents

Abstract

According to the present invention, a motor operated compressor comprises: a first scroll; a second scroll forming a pair of two compression chambers between the first scroll and the second scroll while turning to be engaged with the first scroll; a frame fixed in a radial direction opposite to the first scroll with the second scroll interposed therebetween; a rotating shaft eccentrically coupled to the second scroll; and a back pressure plate provided between the second scroll and the frame to support the second scroll in a direction heading for the first scroll.

Description

[0001] MOTOR OPERATED COMPRESSOR [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compressor, and more particularly, to an electric compressor which is mainly applied to a vehicle including an electric vehicle.

2. Description of the Related Art Generally, compressors for compressing refrigerant in automotive air conditioning systems have been developed in various forms. Recently, electric compressors driven by electric motors using motors have been actively developed according to the tendency of electric parts to be electricized.

Among electric compressors, scroll compressors suitable for high compression ratio operation are mainly applied. [0003] In the scroll type electric compressor, a closed scroll casing is provided with a transmission section formed as a rotary motor, a compression section including a fixed scroll and an orbiting scroll is installed on one side of the transmission section, Is transmitted to the compression section. The rotating force transmitted to the compression section causes the orbiting scroll to swing with respect to the fixed scroll to form a pair of two compression chambers composed of a suction chamber, an intermediate compression chamber and a discharge chamber. The refrigerant is sucked into both compression chambers, Method.

In addition, an inverter type compressor capable of varying the operation speed of a motor, including a constant speed motor, is also being developed as an electric compressor. In the inverter-type electric compressor, the inverter is mounted on the outer circumferential surface or one side surface of the casing, and the inverter is electrically connected to a motor provided inside the casing using a terminal passing through the casing.

On the other hand, the scroll type compressor applied to the air conditioning system for a vehicle is mainly installed in the horizontal type in the engine room structure of the vehicle. Accordingly, the main frame and the subframe are respectively provided for supporting the rotation shaft on both lateral sides of the transmission portion as the transmission portion and the compression portion are arranged in the transverse direction and connected by the rotation shaft.

However, in the conventional electric compressor as described above, the back pressure space in which the refrigerant discharged from the compression chamber and the oil are introduced into the back surface of the orbiting scroll is formed so that the orbiting scroll is supported in the direction toward the fixed scroll However, there is a problem that the back pressure of the back pressure space is excessively or insufficient depending on the operating conditions of the compressor, and the orbiting scroll can not be uniformly supported.

In addition, in the conventional electric compressor, since the orbiting scroll is supported only at a position where the back pressure space is formed, there is a problem that the orbiting scroll can not be stably supported at a portion far from the back pressure space in the radial direction.

In addition, in the conventional electric compressor, a back pressure space for supporting the orbiting scroll in the fixed scroll direction is required, and the length of the compressor is accordingly increased.

U.S. Patent Publication No. US 2014/0134032 A1 (Apr.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electric compressor in which the orbiting scroll can be stably supported even when the back pressure for supporting the orbiting scroll becomes excessive or insufficient.

Another object of the present invention is to provide an electric compressor in which a part for supporting the orbiting scroll in the axial direction is formed to be wide so as to uniformly support the entire orbiting scroll.

Another object of the present invention is to provide an electric compressor capable of reducing the length of the compressor by eliminating or reducing the back pressure space.

An object of the present invention is to provide an electric compressor in which a back pressure member is provided between an orbiting scroll and a frame supporting the orbiting scroll so as to vary the supporting force of the orbiting scroll in response to a pressure change of the compression chamber.

Here, the back pressure member is made of a material having elasticity, and the orbiting scroll can be supported by the elastic force of the back pressure member and the gas pressure of the back pressure space provided in the frame.

The elastic force of the back pressure member may be configured to be provided to the orbiting scroll outside the radial direction of the back pressure space.

In order to achieve the object of the present invention, the first scroll; A second scroll that forms a pair of two compression chambers between the first scroll and the first scroll, while being pivotally engaged with the first scroll; A frame fixed in a radial direction opposite to the first scroll with the second scroll interposed therebetween; A rotating shaft eccentrically coupled to the second scroll; And a back pressure plate provided between the second scroll and the frame, the back pressure plate supporting the second scroll in a direction toward the first scroll.

Here, the second scroll may be provided with a back pressure hole for bypassing the refrigerant in the compression chamber in the direction of the back pressure member.

Further, a back pressure space may be formed in the frame, and the back pressure hole may be formed to communicate with the back pressure space.

The back pressure plate may have an annular back pressure gas receiving groove having a predetermined volume at a portion corresponding to the outlet of the back pressure hole, and the back pressure gas receiving groove may be recessed in a direction toward the frame.

The back pressure gas receiving groove may be formed to be accommodated in the back pressure space.

The second scroll may include a first sealing member in contact with one side of the back pressure plate, and the frame may include a second sealing member in contact with the other side of the back pressure plate.

The second sealing member may be coupled to the back pressure plate.

The back pressure plate may be in contact with the second sealing member on at least two sides.

The frame is formed with a first thrust surface on which the second scroll is axially supported and a second thrust surface on which the second sealing member is axially supported, and the inner diameter of the second sealing member is The outer diameter of the first thrust surface may be larger than the outer diameter of the first thrust surface so that the second sealing member can perform the orbital motion on the second thrust surface.

Here, the back pressure plate may be configured to be coupled to the second scroll and pivotally move together.

A plurality of anti-rotation grooves are formed in the frame. The second scroll is provided with a plurality of anti-rotation pins inserted into the rotation prevention grooves to pivot together with the second scroll, And can be coupled to the second scroll by a pin.

The frame is provided with a plurality of rotation prevention pins, and the rotation prevention pin is inserted into the second scroll, and a plurality of rotation prevention grooves are formed to pivot together with the second scroll. The lubrication ring portion may be formed so as to be inserted and joined to the groove.

In order to achieve the object of the present invention, the first scroll; A second scroll that forms a pair of two compression chambers between the first scroll and the first scroll, while being pivotally engaged with the first scroll; A frame disposed opposite to the first scroll with the second scroll interposed therebetween; And a back pressure plate provided between the second scroll and the frame and elastically supporting the second scroll toward the first scroll while being deformed by the pressure of the refrigerant bypassed in the compression chamber, A rotation prevention pin is coupled to one of the frames and an anti-rotation groove is formed on the other side to insert the rotation prevention pin into the rotation prevention groove, and the back pressure plate is rotatably supported by the rotation prevention pin And the second scroll is coupled to the second scroll.

Here, the frame may be formed with a space portion having a pressure higher than the suction pressure, and at least a part of the back pressure plate may be formed in the space portion.

A back pressure hole is formed in the second scroll to bypass the refrigerant in the compression chamber to the space portion, and a back pressure gas receiving groove may be formed in the back pressure plate so that refrigerant bypassed through the back pressure hole is accommodated .

The balance weight may further include a balance weight for compensating an unbalance caused by the eccentric motion of the second scroll, and the balance weight may be provided outside the frame.

The electric compressor according to the present invention is provided with a back pressure plate between the orbiting scroll and the main frame that varies the elastic force in accordance with the pressure change of the compression chamber. Therefore, even if the back pressure for supporting the orbiting scroll becomes excessive or insufficient, The scroll can be stably supported.

Further, since the back pressure plate supports the orbiting scroll outside the back pressure space of the main frame, a part for supporting the orbiting scroll in the axial direction is formed to be wide, and the entire orbiting scroll can be uniformly supported.

In addition, since the balance weight is provided outside the main frame, the back pressure space is not formed in the main frame, or the volume can be reduced to reduce the length of the compressor.

1 is a sectional view of an electric compressor according to the present invention,
2 and 3 are a cross-sectional view and an exploded perspective view showing a compression mechanism including the back pressure plate according to the present embodiment,
4 is a perspective view showing the back pressure plate according to the present invention as seen from the back pressure space side,
5 is a sectional view taken along the line " IV-IV " in Fig. 4,
6 is a perspective view showing an example in which the back pressure plate according to the present invention is provided between the main frame and the orbiting scroll,
7A and 7B are schematic views showing the degree of deformation of the back pressure plate according to changes in pressure in the compression chamber in the electric compressor of the present invention. FIG. 7A shows a case of high pressure, FIG. 7B shows a case of low pressure,
FIG. 8 is a sectional view showing an example in which an anti-rotation pin is provided on a main frame and an anti-rotation groove is provided on a second scroll, respectively, in the electric compressor according to the present invention,
9 is a cross-sectional view showing an example in which the balance weight is coupled to the rotation shaft from the outside of the main frame.

Hereinafter, an electric compressor according to the present invention will be described in detail with reference to an embodiment shown in the accompanying drawings.

The electric compressor according to the present invention may be a scroll compressor configured to compress refrigerant by engaging two scrolls. The electric compressor according to the present invention may be a component of a refrigeration cycle apparatus that sucks and compresses a refrigerant with a working fluid. In this embodiment, an electric scroll compressor using carbon dioxide (CO ₂ ) as a working fluid will be described as an example. 1 is a sectional view showing an electric compressor according to the present invention.

1 and 2, an electric compressor 100 according to an embodiment of the present invention includes a casing 101, a frame, a drive unit 103, and a compression unit 104, And a subframe 180. The subframe 180 may include a plurality of subframes. For example, the main frame 120 is fixed to the middle of the inner wall of the casing 101, and the driving unit 103 for generating a driving force is installed on one side (front side) of the main frame 120 . A compression unit 104 for receiving the driving force of the driving unit 103 and compressing the refrigerant may be installed on the other side (rear side) of the main frame 120.

In addition, a control unit for controlling the operation of the compressor may be provided outside the casing 101. The control unit may be located on the opposite side of the compression unit 104 with respect to the drive unit 103. [

1, the casing 101 may include a shell 111, a front cover 112, and a rear cover 113. [ The shell 111 is formed in a cylindrical shape with both end portions (front and rear) opened, and a suction space S1 can be formed therein. Inside the shell 111, a drive unit 103, a frame, and a compression unit 104 can be accommodated.

The front cover 112 may be coupled to close the front end of the shell 111, and a control unit, a power supply unit, or the like may be connected to the outside of the front cover 112. The rear cover 113 can be coupled to seal the rear end of the shell 111. [ As will be described later, the rear cover 113 forms a part of the discharge space S2 and may include an oil separation portion 116. [

The suction space S1 can be separated into the first suction space S11 and the second suction space S12 by the drive unit 103 accommodated therein. The first suction space S11 may be formed on the side of the front cover 112 and the second suction space S12 may be formed on the side of the rear cover 113. [ The first suction space S11 and the second suction space S12 are connected to each other through a plurality of communication passages 111a formed between the outer peripheral surface of the stator 131 provided in the drive unit 103 and the inner peripheral surface of the shell 111 And can communicate with each other. The refrigerant is sucked into the first suction space S11 on the side of the front cover 112 and then moved to the second suction space S12 on the frame side through the drive unit 103. [

The front cover 112 may be formed with an intake port 114 through which a suction pipe is connected to allow the refrigerant to flow into the suction space S1. The intake port 114 may be formed so as to be positioned at the front end of the drive unit 103 which is opposite to the compression unit 104 with respect to the drive unit 103. [ Thereby, the refrigerant flows into the inside of the casing 101 through the intake port 114, and can be sucked into the compression unit 104 after passing the drive unit 103 from the front side to the rear side.

In addition, the rear cover 113 may have an exhaust port 115 through which the discharge pipe is connected to guide the refrigerant compressed by the compression unit 104 to the refrigeration cycle. The rear space of the compression unit 104 closed by the rear cover 113 may be the discharge space S2 communicating with the exhaust port 115. [ The oil separator 116 separating the oil from the mixture of the refrigerant and the oil to be discharged may be formed in the path from the discharge space S2 to the discharge port 115. [ 1 shows an embodiment in which the oil separator 116 communicating with the discharge space S2 separates refrigerant and oil from each other by centrifugal force. The oil separated from the refrigerant can be accumulated in the recovery space 116a formed on the bottom surface of the oil separation portion 116. [

The driving unit 103 includes a stator 131 and a rotor 132, and generates a rotational force for driving the rotating shaft 135. [ In this embodiment, the stator 131 is fixed to the inner circumferential surface of the shell 111 and may have an annular shape to form a cylindrical space therein. The rotor 132 may be disposed in the inner space of the stator 131 so as to be spaced apart from the stator 131. The rotor 132 may have a substantially cylindrical shape, and a rotation shaft 135 may be coupled to the center thereof. When power is supplied to the drive unit 103, the rotor 132 and the rotary shaft 135 can be rotated together by the interaction between the stator 131 and the rotor 132. [

The rotary shaft 135 can be received in the shell 111 and rotatably supported on the frame. The rear side of the rotary shaft 135 may be supported in a radial direction by a main bearing 161 mounted on the main frame 120. The front end of the rotation shaft 135 may be supported in a radial direction by a sub bearing 162 mounted on the subframe 180 formed on the inner surface of the front cover 112. A portion of the outer circumferential surface of the rotary shaft 135 may be coupled to the rotor 132 to receive a rotational force generated by the drive unit 103.

The compression unit 104 may include a first scroll 140 that is a fixed scroll and a second scroll 150 that is a orbiting scroll. The second scroll 150 is eccentrically coupled to the rotary shaft 135 coupled to the rotor 132 of the drive unit 103 and rotates relative to the first scroll 140, A pair of compression chambers P consisting of a cylinder, an intermediate pressure chamber, and a discharge chamber are formed.

The first scroll 140 is provided with a fixed side plate portion 141 in a circular plate shape and a fixed side wall portion 142 protruding toward the main frame 120 is formed on one side of the fixed side plate portion 141 .

A fixed lap 143 for engaging with the orbiting wrap 152 to be described later and forming a pair of two compression chambers P is protruded and formed at the center of the fixed side rigid plate 141, And a discharge port 144 communicating with the discharge space S2 from the final compression chamber is formed at the center of the fixed side end plate 141. The discharge port 144 communicates with the suction space S1 of the casing 101, Can be formed.

The second scroll 150 is formed in a disk shape with a turning side end plate portion 151 and is projected toward the fixed side end plate portion 141 on one side of the turning side end plate portion 151 to be engaged with the fixed lap 143 And a boss groove 153 is formed in the other side surface of the turnable side plate 151 so that an eccentric bearing 163 for supporting the rotation axis 135 is inserted and fixed.

A first sealing groove 154 is formed in an annular shape so that a first sealing member 165 to be described later is inserted into the other side edge of the turn side plate 151. The boss groove 153 and the first sealing groove A back pressure hole 155 is formed to pass through the intermediate pressure chamber toward the back pressure space 124 to be described later.

Meanwhile, the main frame 120 may include a body 121 and a bearing 122. The outer circumferential portion of the body portion 121 may be coupled to the fixed side wall portion 142 of the first scroll 140 and the inner surface of the casing 101 to be supported. The body portion 121 may have a thrust surface 123 which is capable of slidably supporting the second scroll 150 and sliding with the turn side light guide plate 151 of the second scroll 150. The thrust surface 123 may be divided into a first thrust surface 123a and a second thrust surface 123b.

A back pressure space 124 for supporting the second scroll 150 toward the first scroll 140 is formed at the center of the body portion 121. A back pressure space 124 is formed in the back pressure space 124, A balance weight 136 can be rotatably received to compensate for the imbalance due to the eccentric motion of the scroll 150. The back pressure space 124 will be described later together with the back pressure plate 190. In addition, the balance weight 136 may be provided outside the main frame 120, which will be described later.

The bearing 122 is capable of supporting the rotating shaft 135 through the main bearing 161. The shaft receiving portion 122 may be formed to surround the outer circumferential surface of the rotation shaft 135 at the center of the body portion 121. [ A main bearing 161 is coupled to the inner circumferential surface of the shaft receiving portion 122 and the rotating shaft 135 can be rotatably supported by the main bearing 161.

A plurality of rotation prevention pins 171 and rotation prevention grooves 172 may be provided between the main frame 120 and the second scroll 150 to prevent rotation. In this embodiment, a plurality of rotation prevention pins 171 are fixedly coupled to one side surface (front surface) of the turning side rigid plate 151 of the second scroll 150, and the corresponding throttle surface of the main frame 120 A plurality of anti-rotation grooves 172 may be formed on the base plate 123. The plurality of anti-rotation pins 171 are inserted into the plurality of anti-rotation grooves 172, and the anti-rotation pins 171 slide in the anti-rotation grooves 172 while rotating together with the orbiting scroll 150, The rotation of the rotor is prevented. The rotation preventing groove 172 may be provided with a lubricating ring 173 made of a material having a high abrasion strength in consideration of friction with the rotation preventing pin 171. [

The rotation prevention pin 171 is provided on the orbiting scroll 150 and the rotation prevention groove 172 is provided on the main frame 120 in the present embodiment. And a rotation preventing groove may be provided in the orbiting scroll, respectively. This will be described later.

Meanwhile, the subframe 180 may be formed at a position spaced apart from the main frame 120 to support the other end of the rotation shaft 135. The subframe 180 may be fixed to the casing 101, and may be integrally formed with the front cover 112, as in the present embodiment. The subframe 180 may have a boss portion 181 protruding from the inner surface of the front cover 112 to surround the end portion of the rotation shaft 135. A sub-bearing 162 is inserted between the inner circumferential surface of the boss portion 181 and the outer circumferential surface of the rotation shaft 135 so that the rotation shaft 135 can be rotatably supported.

In the drawing, reference numerals 165, 166, and 167 denote a first sealing member, a second sealing member, and a third sealing member, respectively.

The electric compressor according to the present invention operates as follows.

First, when power is applied to the driving unit 103, the rotating shaft 135 rotates together with the rotor 132 of the driving unit 103 to transmit rotational force to the second scroll 150. The second scroll 150 eccentrically connected to the rotating shaft 135 is pivoted by the eccentric distance by the rotation preventing pin 171 and the rotation preventing groove 172, 135, and the volume is decreased.

Accordingly, the refrigerant flows into the first suction space S11 through the suction port 114. [ The refrigerant flowing into the first suction space S11 flows through the communication passage 111a or the gap between the stator 131 and the rotor 132 and flows into the second suction space S12. At this time, the coolant can cool the stator 131 and the rotor 132.

Thereafter, the refrigerant sucked into the compression chamber P is compressed while being moved toward the center side along the movement path of the compression chamber P, and is discharged through the discharge opening formed in the discharge space formed between the first scroll 140 and the rear cover 113 S2.

The refrigerant discharged to the discharge space S2 is separated from the oil in the discharge space S2 or the oil component is separated while passing through the oil separator 116 and the refrigerant is discharged to the refrigeration cycle through the discharge port 115. [ On the other hand, the separated oil may remain in the recovery space 116a of the oil separator 116 and be recovered.

In the scroll type electric compressor 100, the second scroll 150, which is the orbiting scroll, is pushed in the direction away from the first scroll 140, which is the fixed scroll, by the gas force of the compression chamber P during driving. . The refrigerant compressed in the compression chamber P between the first scroll 140 and the second scroll 150 is leaked in the axial direction and the second scroll 150 is brought into close contact with the main frame 120 The friction loss can be increased. Therefore, conventionally, by bypassing a part of the refrigerant compressed in the compression chamber P to the back pressure space 124 or moving the oil in the discharge space S2 to the back pressure space 124, The second scroll 150 floats toward the first scroll 140 to prevent leakage of the refrigerant compressed in the compression chamber P and reduces the frictional resistance at the thrust surface 123 to reduce the friction loss there was.

However, when the orbiting scroll 150 is supported only by the back pressure of the back pressure space 124, the pressure in the back pressure space 124 excessively increases or becomes insufficient depending on the operating condition of the compressor, It may not be uniformly supported. In addition, as the orbiting scroll 150 is supported only at the position where the back pressure space 124 is formed, the portion that is located radially farther from the back pressure space 124 may not be able to stably support the orbiting scroll 150 have. In addition, the length of the compressor may be increased by the length of the back pressure space 124.

In view of this, in this embodiment, in addition to the back pressure of the back pressure space, a back pressure plate serving as a kind of lever between the frame and the orbiting scroll can be provided so as to mechanically support the orbiting scroll. 2 and 3 are a cross-sectional view and an exploded perspective view showing a compression mechanism including the back pressure plate according to the present embodiment.

2 and 3, the thrust surface 123 of the main frame 120 may include a first frame thrust surface 123a and a second frame thrust surface 123b. The first frame thrust surface 123a is formed inward to axially support the second scroll 150 and the second frame thrust surface 123b is formed to axially support the second sealing member 166, And is formed outside the first frame thrust surface 123a.

The first frame thrust surface 123a and the second frame thrust surface 123b may be stepped to have a predetermined height difference. For example, the first frame thrust surface 123a is formed slightly higher than the second frame thrust surface 123b so that the second sealing member 166 is inserted into the outer peripheral surface of the first frame thrust surface 123a .

Inside the first frame thrust surface 123a, a deformation space 125 may be formed so that the back pressure portion 192 of the back pressure plate 190, which will be described later, is bent. The deformation space 125 may be formed obliquely, but it may be advantageous from the viewpoint of processing that the deformation space 125 is formed stepwise as shown in FIG. The deformation space 125 can serve as a kind of retainer for restricting the extent to which the back pressure portion 192 of the back pressure plate 190 is deformed.

The rotation prevention groove 172 is formed in the first frame thrust surface 123a such that the rotation prevention pin 171 described above is pivotally inserted. The plurality of anti-rotation grooves 172 are formed at regular intervals along the circumferential direction. As described above, a lubricating ring 172 having a predetermined rigidity can be inserted into the rotation preventing groove 172 in consideration of the friction with the rotation preventing pin 171, respectively. A plurality of lubrication prevention rings may be integrally formed.

As described above, a back pressure space 124 for supporting the back surface of the second scroll 150 is formed at the center of the main frame 120. A part of the refrigerant communicated with the back pressure space (155) of the swivel side plate portion (150) is introduced into the back pressure space (124) through the back pressure hole (155) from the intermediate pressure chamber. In addition, the back pressure space 124 communicates with the discharge space S2 and the oil discharged into the discharge space S2 may be depressurized and introduced. Accordingly, the pressure in the back pressure space 124 becomes an intermediate pressure between the pressure in the suction space S1 and the final pressure (i.e., the discharge pressure) of the compression chamber P.

The back pressure space 124 includes a first sealing member 165 provided between the back pressure plate 190 and the second scroll 150, a back pressure plate 190, A second sealing member 166 provided between the frame 120 and a third sealing member 167 provided between the inner circumferential surface of the main frame 120 and the outer circumferential surface of the rotary shaft 135.

The first sealing member 165 is formed in an annular shape having a rectangular sectional shape or a V (V) sectional shape and is inserted into a sealing groove 154 provided on one side (back pressure side) of the turning side end plate portion 151 . In this case, the first sealing member 165 is pushed by the force of the pressure in the back pressure space 124 and can seal between the back pressure plate 190 and the second scroll 150 while closely contacting the back pressure plate 190 .

The second sealing member 166 is formed in a rectangular cross-sectional shape and can be coupled to the back pressure plate 190. In this case, the second sealing member 166 may be coupled to the second scroll 150 by a back pressure plate 190, which will be described later, and may be provided so as to pivot about the second frame thrust surface 123b . The second sealing member 166 will be described again with reference to the back pressure plate.

The third sealing member 167 may be formed in an annular shape having a U-shaped sectional shape and may be coupled to the bearing portion 122 of the main frame 120. A sealing groove (not shown) formed in an annular shape along the inner circumferential surface of the shaft receiving portion 122 of the main frame 120 is formed and the third sealing member 167 described previously in the sealing groove can be inserted. In this case, the third sealing member 167 is opened by the force of the pressure in the back pressure space 124, and can seal the back pressure space 124 while closely contacting the outer circumferential surface of the rotation shaft 135. However, the third sealing member 167 may be omitted in some cases. When the third sealing member 167 is excluded, the back pressure space 124 communicates with the suction space S1 through the fine passage formed on the inner circumferential surface of the main bearing 161 provided in the bearing portion 122 of the main frame 120. [ The pressure of the back pressure space 124 can be prevented from stagnating so that the oil can smoothly flow into each bearing hole.

The back pressure plate 190 may be provided between the main frame 120 and the corresponding second scroll 150, as described above. The back pressure plate 190 is supported by pushing the second scroll 150 in the direction toward the first scroll 140 while being deformed by the pressure of the refrigerant bypassed in the intermediate pressure chamber through the back pressure hole 155. Fig. 4 is a perspective view showing the back pressure plate according to the present invention viewed from the back pressure space side, Fig. 5 is a sectional view taken along the line IV-IV in Fig. Which is a broken-away perspective view.

4 to 6, the back pressure plate 190 is formed in an annular shape corresponding to the first frame thrust surface 123a. The back pressure plate 190 may be formed by pressing a thin flat plate so as to be flexibly bent. The back pressure plate 190 may be formed of a material having elasticity more than the main frame 120 or the second scroll 150.

The back pressure plate 190 may include a pressing portion 191, a back pressure portion 192, and a sealing portion 193.

The pressing portion 191 is formed as a middle portion of the back pressure plate and is disposed between the main frame 120 and the second scroll 150 to be formed into a flat annular shape so as to apply a back pressure to the second scroll 150 do. A plurality of pin holes 191a are formed in the pressing portion 191 along the circumferential direction so that the rotation prevention pins 171 are inserted.

The back pressure part 192 is formed in the inner peripheral part of the back pressure plate 190 and is located in the deformation space 125 or the back pressure space 124 of the main frame 120 to generate a deforming force. Accordingly, although the back pressure unit 192 may be formed flat, the back pressure gas receiving groove 192a may be formed in the annular shape to accommodate the refrigerant bypassed through the back pressure hole 155.

The back pressure gas receiving groove 192a may be formed by being bent so as to sink toward the main frame 120, that is, toward the back pressure space 124. [ The back pressure gas receiving groove 192a may be formed at a position overlapping the back pressure hole 155 in the radial direction.

The sealing portion 193 is formed on the outer peripheral portion of the back pressure plate 190 and is positioned on the second frame thrust surface 123b of the main frame 120 to seal the back pressure space 124. [

5, the sealing portion 193 may be bent to form the second sealing member 166. The second sealing member 166 may be fixed to the second sealing member 166 by being bonded to the first sealing member 166, 166, it is preferable to increase the sealing area. In this case, the sealing portion 193 may be in contact with the upper surface and the outer surface of the second sealing member 166. The second sealing member 166 is supported by the sealing portion 193 of the back pressure plate 190 so that when the second scroll 150 pivots in the main frame 120, And slide along with the back pressure plate 190 at the second frame thrust surface 123b of the main frame 120. [

The process of raising the second scroll in the first scroll direction in the electric compressor according to the present embodiment is as follows.

That is, a part of the refrigerant compressed in the compression chamber P is bypassed to the back pressure space 124 through the back pressure hole 155 in the intermediate pressure chamber, and this refrigerant acts as a back pressure in the back pressure space 124, Thereby pushing the scroll 150 toward the first scroll 14. [ The oil is separated from the refrigerant discharged to the discharge space S2 so that the oil flows from the oil returning part 166a to the back pressure space 124 while being decompressed through a separate flow path and flows into the back pressure space 124 The oil forms the backpressure with the refrigerant.

The orbiting wrap 152 of the second scroll 150 is engaged with the fixed side end plate 141 of the first scroll 140 and the orbiting side end plate 151 of the second scroll 150 is engaged with the first scroll 140 Tightly sealing the compression chambers P while being closely attached to the fixed wraps 143 of the compression chambers.

At the same time, the refrigerant bypassed from the intermediate pressure chamber of the compression chamber P to the back pressure space 124 of the main frame 120 through the back pressure hole 155 of the second scroll 150 is returned to the back pressure of the back pressure plate 190 And the pressure of the refrigerant pushes the back pressure portion 192 of the back pressure plate 190 toward the back pressure space 124, that is, away from the second scroll 150.

The back pressure portion 192 of the back pressure plate 190 and the sealing portion 193 are pressed toward the back pressure space (i.e., the main frame), and the back pressure portion 192 and the sealing portion 193 The pressing portion 191 is bent convexly in the direction toward the second scroll 150 which is opposite to the direction in which the back pressure portion 192 and the sealing portion 193 are pressed.

The pressing portion 191 of the back pressure plate 190 presses the second scroll 150 toward the first scroll 140 in addition to the back pressure of the back pressure space 124. As a result, the second scroll 150 is lifted and brought into close contact with the first scroll 140, so that refrigerant leakage in the compression chamber P can be more effectively suppressed.

When the second scroll 150 is mechanically supported by the back pressure plate 190 between the main frame 120 and the second scroll 150 as described above, The discharge pressure for the second scroll 150 is differentiated. FIGS. 7A and 7B are schematic views showing the degree of deformation of the back pressure plate according to changes in pressure in the compression chamber in the electric compressor of the present invention. FIG. 7A is a diagram showing a case of high pressure and FIG.

7A, when the pressure in the compression chamber P is high, the high-pressure refrigerant is delivered to the back pressure portion 192 of the back pressure plate 190 through the back pressure hole 155, and the back pressure portion 192 are subjected to a high pressure and are greatly deflected in the direction opposite to the second scroll (150). The pressing portion 191 of the back pressure plate 190 is deformed by the first height t1 toward the second scroll 150 which is opposite to the back pressure portion 192 and a high back pressure is applied to the second scroll 150 . Then, the second scroll 150 is strongly urged toward the first scroll 140 while being floated to the first scroll 140. At this time, the back pressure plate 190 is largely deformed so that the first sealing member 165 is strongly adhered to the rear surface of the back pressure plate 190 and the second sealing member 166 is strongly adhered to the second frame thrust surface 123b It is possible to suppress leakage of the refrigerant or oil in the back pressure space 124. Accordingly, even when the pressure in the compression chamber P is high, it is possible to effectively prevent the refrigerant in the compression chamber P from leaking.

7B, when the pressure in the compression chamber P is low, the pressing portion 191 of the back pressure plate 190 is deformed to be smaller by the second height t2, Lt; / RTI > Then, the second scroll 150 floats relatively low toward the first scroll 140, and the two scrolls 140 and 150 are weakly adhered to each other. Accordingly, when the pressure in the compression chamber P is low, the second scroll 150 is excessively brought into close contact with the first scroll 140, thereby preventing the frictional resistance and the friction loss from being increased.

Further, since the back pressure plate 190 is provided between the main frame 120 and the second scroll 150 as in the present embodiment, the back pressure of the back pressure space 124 serves as a center portion of the second scroll, The back pressure plate 190 pushes the edge portions of the second scroll 150 toward the first scroll 140, respectively. As a result, the sealing force between the first scroll 140 and the second scroll 150 can be further increased since the center portion and the edge portion of the second scroll 150 receive a uniform pressure.

On the other hand, in the above-described embodiment, the rotation preventing pins are provided in the second scroll and the rotation preventing grooves are provided in the main frame, respectively. In contrast, Can be applied. 8 is a cross-sectional view illustrating an example in which an anti-rotation pin is provided on a main frame and a rotation preventing groove is provided on a second scroll, respectively, in the electric compressor according to the present invention.

As shown in the figure, in this embodiment, the rotation prevention pin 171 is inserted and fixed to the main frame 120, and the rotation prevention groove 172 is formed in the second scroll 150. Even in this case, the basic configuration and operation, and the operation and effect thereof are the same as in the above-described embodiment. In this embodiment, since the back pressure plate 190 is in a free state with respect to the rotation prevention pin 171 in a state where the back pressure plate 190 is coupled to the second scroll 150, The number of the lubricating ring portions 191b may be formed to protrude. The plurality of lubricating ring portions 191b are inserted and fixed in the plurality of rotation preventing grooves 172 provided in the second scroll 150 and the rotation preventing pins 171 are fixed to the rotation preventing grooves 172 by the lubricating ring portions 173. [ So that the second scroll 150 can be prevented from rotating.

Accordingly, the back pressure plate 190 rotates together with the second scroll 150, and the second scroll 150 is rotated by the medium-pressure refrigerant discharged through the back pressure hole 155 as in the above- 1 scroll 140 so that the compression chamber P can be tightly sealed.

Hereinafter, another embodiment of the electric compressor according to the present invention will be described.

That is, in the above-described embodiments, the balance weight is provided in the back pressure space of the main frame. However, in the present embodiment, the balance weight is provided outside the back pressure space of the main frame, or more accurately, outside the main frame. 9 is a sectional view showing an example in which the balance weight is coupled to the rotation shaft from the outside of the main frame.

As shown in the drawing, the main frame 120 is formed with a bearing water portion 122 into which the rotation shaft 135 is inserted, and a back pressure portion 192 of the back pressure plate 190 is formed at the rear side end portion of the bearing water portion 122 The space portion 126 having a volume that can be deformed can be formed in an annular shape.

The space portion 126 has a width such that the back pressure portion 192 of the back pressure plate 190 can be bent in a direction toward the main frame 120 which is opposite to the second scroll 150. Therefore, the space portion 126 can have a significantly smaller volume (more precisely, the axial depth) than the back pressure space 124 described above. For example, the volume of the space portion 126 may be formed to have a smaller volume than the volume of the final compression chamber P, or to have a depth shallower than the thickness of the turning-side end plate portion 151.

Further, in this embodiment, the main bearing 120 is a ball bearing, but in some cases, the main bearing may be a bush bearing. When the main bearing is made of a bush bearing, the third sealing member may not be provided.

Even when the balance weight 136 is provided outside the main frame 120 as in the present embodiment, its basic configuration, operation, and operation are the same as those of the above-described embodiments. However, in this embodiment, as the balance weight 136 is coupled to the rotary shaft 135 from the outside of the main frame 120 or coupled to the rotor 132, the second scroll 150 is moved in the direction of the back pressure plate 190, It can be supported only in the axial direction.

Accordingly, the electric compressor of the present embodiment can eliminate or minimize the back pressure space, thereby reducing the overall length of the compressor and achieving miniaturization.

100: electric compressor 101: casing
103: drive unit 104: compression unit
111: Shell 112: Front cover
113: rear cover 114: intake port
115: exhaust port 116: oil separator
116a: Collection space 120: Main frame
121: Body part 122: Bearing part
123: thrust surface 124: back pressure space
125: deformation space 126: space part
135: rotation axis 136: balance weight
140: first scroll 141: fixed side hard plate
143: stationary lap 144: outlet
150: Second scroll 151:
152: turning lap 155: back pressure hole
161: main bearing 162: sub bearing
163: eccentric bearing 165: first sealing member
166: second sealing member 171: anti-rotation pin
172: anti-rotation groove 173: lubricating ring
190: back pressure plate 191:
191a: Pin hole 191b: Lubricating ring part
192: back pressure part 192a: exhaust gas receiving groove
193:

Claims (16)

First scroll;
A second scroll that forms a pair of two compression chambers between the first scroll and the first scroll, while being pivotally engaged with the first scroll;
A frame fixed in a radial direction opposite to the first scroll with the second scroll interposed therebetween;
A rotating shaft eccentrically coupled to the second scroll; And
And a back pressure plate provided between the second scroll and the frame for supporting the second scroll in a direction toward the first scroll,
And a back pressure hole is formed in the second scroll to bypass the refrigerant in the compression chamber in a direction toward the back pressure plate. delete The method according to claim 1,
Wherein a back pressure space is formed in the frame, and the back pressure hole is formed to communicate with the back pressure space. The method of claim 3,
Wherein the back pressure plate has a back pressure gas receiving groove formed in an annular shape in a portion corresponding to the outlet of the back pressure hole,
Wherein the back pressure gas receiving groove is formed to be recessed in a direction toward the frame. 5. The method of claim 4,
And the back pressure gas receiving groove is formed to be accommodated in the back pressure space. The method according to claim 1,
And a second sealing member which is in contact with one side surface of the back pressure plate is provided in the second scroll,
Wherein the frame is provided with a second sealing member in contact with the other side surface of the back pressure plate. The method according to claim 6,
And the second sealing member is coupled to the back pressure plate. 8. The method of claim 7,
Wherein the back pressure plate is in contact with at least two sides of the second sealing member. 9. The method of claim 8,
Wherein the frame has a first thrust surface on which the second scroll is axially supported and a second thrust surface on which the second sealing member is axially supported,
Wherein an inner diameter of the second sealing member is formed to be larger than an outer diameter of the first thrust surface so that the second sealing member can pivot on the second thrust surface. 10. The method according to any one of claims 1 to 9,
And the back pressure plate is engaged with the second scroll to pivot together. 11. The method of claim 10,
The frame includes a plurality of rotation preventing grooves, and the second scroll has a plurality of rotation preventing pins inserted into the rotation preventing grooves to pivot together with the second scrolls,
And the back pressure plate is coupled to the second scroll by the anti-rotation pin. 11. The method of claim 10,
The frame includes a plurality of rotation prevention pins. The rotation prevention pin is inserted into the second scroll, and a plurality of rotation prevention grooves are formed to pivot together with the second scroll.
Wherein the back pressure plate is formed with a lubricating ring portion to be inserted into the rotation preventing groove. First scroll;
A second scroll that forms a pair of two compression chambers between the first scroll and the first scroll, while being pivotally engaged with the first scroll;
A frame disposed opposite to the first scroll with the second scroll interposed therebetween; And
And a back pressure plate provided between the second scroll and the frame for elastically supporting the second scroll toward the first scroll while being deformed by the pressure of the refrigerant bypassed in the compression chamber,
A rotation preventing pin is coupled to either one of the second scroll and the frame and a rotation preventing groove is formed on the other of the frame and the frame so that the rotation preventing pin is inserted to perform the turning movement,
And the back pressure plate is coupled to the second scroll by the rotation prevention pin or the rotation preventing groove. 14. The method of claim 13,
Wherein a space portion forming a pressure higher than a suction pressure is formed in the frame, and at least a part of the back pressure plate is formed in the space portion. 15. The method of claim 14,
A back pressure hole is formed in the second scroll to bypass the refrigerant in the compression chamber to the space portion,
And a back pressure gas receiving groove is formed in the back pressure plate so that refrigerant bypassed through the back pressure hole is received. 15. The method of claim 14,
Further comprising a balance weight for compensating an imbalance caused by the eccentric motion of the second scroll,
And the balance weight is provided outside the frame.

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