KR20200002471A - Scroll compressor - Google Patents

Abstract

The present invention provides a compressor capable of forming appropriate back pressure in accordance with a driving condition of the compressor. The compressor includes: a first scroll including a fixing lap; a second scroll including a turning lap and an end plate unit supporting the turning lap, wherein the turning lap forms a compression chamber between the turning lap and the first scroll while turning by being engaged with the fixing lap; a frame having a back-pressure space between the frame and the second scroll and supporting the second scroll in the direction of facing the first scroll by the pressure of the back-pressure space; and a variable back-pressure unit formed in the end plate unit. The variable back-pressure unit has first and second back-pressure flow paths connecting the compression chamber and the back-pressure space. The first and second back-pressure flow paths are connected to different positions of the compression chamber. The compression chamber and the back-pressure space are connected by the first back-pressure flow path or the second back-pressure flow path in accordance with a turning speed of the second scroll.

Description

Scroll Compressor {SCROLL COMPRESSOR}

The present invention relates to a compressor, and more particularly to a scroll compressor.

In general, the compressor that serves to compress the refrigerant in the vehicle air conditioning system has been developed in various forms, and in recent years, the development of the electric compressor driven by the electric using the motor is actively made according to the trend of the lengthening of the automotive parts.

Among the various compression methods, the motor-driven compressor mainly adopts a scroll compression method suitable for high compression ratio operation. In the scroll-type electric compressor, a motor part made of a rotating motor is installed in the sealed casing, and a compression part made of a fixed scroll and a swing scroll is installed at one side of the motor part. In addition, the motor unit and the compression unit are connected to the rotating shaft so that the rotational force of the motor unit is transmitted to the compression unit. The rotational force transmitted to the compression unit pivots the swinging scroll with respect to the fixed scroll to form two pairs of compression chambers, a suction chamber, an intermediate pressure chamber, and a discharge chamber, and the refrigerant is sucked into both compression chambers to compress and discharge at the same time. do.

In the scroll compression method, a back pressure space is formed to press the swing scroll to closely adhere to the fixed scroll to maintain the closed state of the compression chamber. Typically, the back pressure space is formed to communicate with the intermediate pressure chamber or the discharge pressure chamber. Accordingly, a medium pressure or discharge pressure refrigerant is accommodated in the back pressure space to press the swing scroll in the direction toward the fixed scroll.

On the other hand, the oil may be introduced into the back pressure space through the oil passage. The introduced oil is used for lubrication of the friction surface such as the thrust surface for pressing the swing scroll, and forms a flow out of the back pressure space during the rotation operation of the swing scroll.

However, conventional oil outflow and inflow structure of the back pressure space, there is a problem that the flow of oil is not formed in the optimum conditions according to the operating environment of the electric compressor. Specifically, the compressor generates frictional losses due to the close contact between the swinging scroll and the fixed scroll and the loss caused by the refrigerant leaking through the gap between the swinging scroll and the fixed scroll.

These losses will depend on the operating conditions of the compressor, the main loss factor. In low speed operation of the compressor, the loss due to the refrigerant leaking through the gap between the fixed scroll and the swing scroll is increased rather than the friction between the fixed scroll and the swing scroll. Therefore, it is required to form a relatively high back pressure in the back pressure space to reduce the leaking refrigerant.

On the other hand, in the high speed operation of the compressor, the loss due to the friction between the fixed scroll and the swing scroll increases more than the loss due to the refrigerant leaking through the gap between the fixed scroll and the swing scroll. Therefore, a relatively low back pressure is formed in the back pressure space to reduce the friction between the fixed scroll and the swing scroll.

That is, it is required to provide a method for forming a suitable back pressure in the back pressure space according to the operating conditions of the electric compressor.

One object of the present invention is to provide a compressor in which an appropriate back pressure can be formed according to the operating conditions of the compressor in order to solve the above-mentioned problems.

A second object of the present invention is to provide a compressor in which oil can flow into the compression chamber through a flow path formed in the swinging scroll.

The compressor according to the present invention includes a first scroll having a fixed wrap, a pivoting wrap that forms a compression chamber between the first scroll and the rotating wrap in engagement with the fixed wrap, and a hard plate portion for supporting the pivoting wrap. A variable back pressure formed in the frame and the hard plate portion to form a back pressure space between the second scroll and the second scroll so that the second scroll is supported in the direction toward the first scroll by the pressure of the back pressure space. And a unit, wherein the variable back pressure unit forms first and second back pressure passages connecting the compression chamber and the back pressure space, and the first and second back pressure passages communicate with a compression chamber having different pressures. According to the turning speed of the second scroll, the compression chamber and the back pressure space may be communicated through the first back pressure passage or the second back pressure passage.

The variable back pressure unit may include a variable back pressure chamber having a space formed inside the hard plate part, a mass body provided to be movable in the variable back pressure chamber, and an elastic member elastically supporting the mass body toward the center of the hard plate part. Can be.

Here, the mass body is the first position and the second back pressure flow path is closed and the second back pressure flow path is opened by the centrifugal force and the inertia force of the elastic member, the second back pressure flow path is closed. It can move between the opened second positions.

Here, the hard plate portion is formed to penetrate the surface facing the first scroll, and communicates with the first and second holes and the surface facing the frame and the variable back pressure chamber communicating the compression chamber and the variable back pressure chamber and the variable back pressure chamber and It may include a third hole in communication with the back pressure space.

The first back pressure passage may include the first hole and the third hole, and the second back pressure passage may include the second hole and the third hole.

In addition, the first hole and the second hole may be disposed along the radial direction, and may be formed to be radially spaced apart from the turning wrap.

In addition, the third hole may be disposed between the first hole and the second hole. In this case, when any one of the first hole or the second hole is in communication with the third hole, the other may be formed to be blocked by the mass.

In addition, the variable back pressure chamber extends in the radial direction of the hard plate portion, the mass may be formed smaller than the radial length of the variable back pressure chamber.

Here, the mass body may extend in the radial direction of the hard plate portion, and may form a flow path portion having a reduced cross-sectional area toward the center of the mass body.

Here, the length of the flow path portion may be formed smaller than the distance between the first hole and the second hole.

According to the invention, the variable back pressure unit may be provided in plurality in the circumferential direction of the hard plate portion.

Here, the variable back pressure unit may be disposed symmetrically with respect to the center of the second scroll.

According to the present invention, a rotation shaft coupled to the second scroll to transmit the rotational force of the transmission unit may be further included, and the rotation shaft may be coupled through the frame, the second scroll, and the first scroll sequentially.

Here, the rotation shaft is in communication with the oil flow path and the oil flow path extending in the axial direction therein, and includes a plurality of oil supply holes communicating with the frame, the second scroll and the bearing surface between the first scroll and the rotating shaft. The plurality of oil supply passages may communicate with the back pressure space.

The oil supply hole may include a plurality of oil supply holes, and may be respectively formed in an area overlapping the second scroll and an area overlapping the main frame, and the oil flowing into the back pressure space through the oil supply hole may be the first back pressure flow path or the first oil supply hole. It may be introduced into the compression chamber through any one of the two back pressure passage.

According to another aspect of the present invention, a compression chamber is formed between the first scroll and the second scroll, the compression chamber to compress the fluid by reducing the volume while moving from the outside to the inside, the frame for supporting the second scroll and the second scroll And a variable back pressure chamber and a variable back pressure chamber formed inside the second scroll to be disposed between the compression chamber and the back pressure space to support the second scroll toward the first scroll. And a plurality of back pressure passages communicating with different positions, and the compression chamber and the back pressure space may communicate with any one of the plurality of back pressure passages according to the driving speed of the second scroll.

Here, the second scroll is formed with a key groove coupled to the key portion of the Oldham ring, the variable back pressure chamber may be formed at intervals in the circumferential direction with the key groove.

In addition, the oil storage unit is formed on the opposite side of the variable back pressure chamber, the oil storage unit for storing the oil between the compression chamber, and stored in the oil storage unit through the oil passage formed on the rotating shaft for applying a rotational force to the second scroll Only oil is introduced into the back pressure space, and the oil introduced into the back pressure space may be introduced into the compression chamber through any one of the first and second back pressure passages.

The motor-driven compressor according to the present invention can form a different back pressure according to the drive speed of the compressor by the variable back pressure unit formed in the hard plate portion of the second scroll that performs the swing motion.

When the compressor is driven at a high speed, a relatively low back pressure is formed in the back pressure space to reduce the friction loss between the first scroll and the second scroll, and when the compressor is driven at a low speed, a relatively high back pressure is formed. The amount of refrigerant leaking through the gap between the first scroll and the second scroll can be reduced, so that the efficiency of the compressor can be increased.

In addition, since the variable back pressure chamber is formed in the swing scroll, the weight of the swing scroll can be reduced by the reduced material to form the variable back pressure chamber.

In addition, since it is not necessary to form a separate back pressure flow path in the fixed scroll, the scrap can be made larger as much as the space in which the conventional back pressure flow path is formed. In addition, since the length of the flow path is shorter than that of the back pressure flow paths formed in the existing fixed scroll and the frame, the pressure drop can be reduced.

In addition, since the back pressure equal to the pressure of the compression chamber can be formed during the initial startup, it is possible to prevent the initial startup failure.

In addition, the first and second back pressure passages may be utilized as oil passages for supplying oil to the compression chamber. For this reason, oil supply to a compression chamber can be made smooth.

In addition, since a portion of the refrigerant may flow into the back pressure space, a bypass hole for preventing overcompression of the refrigerant may be omitted. This makes it possible to increase the overall efficiency of the compressor.

1 is a cross-sectional view of a compressor according to an embodiment of the present invention.
2 is an enlarged cross-sectional view of a portion of the compression unit in FIG. 1.
3 is a perspective view of a second scroll according to the present invention;
4 is a cross-sectional view taken along line A of the second scroll shown in FIG. 3.
5A is a perspective view of a mass body according to one embodiment of the present invention,
5B and 5C are perspective views of a mass body according to another embodiment of the present invention.
6 is a perspective view of a second scroll according to another embodiment of the present invention.
FIG. 7A is a cross-sectional view taken along line B of the second scroll shown in FIG. 3.
FIG. 7B is a cross-sectional view taken along the line C of the second scroll shown in FIG. 3.
8 is a view showing a variable back pressure unit according to another embodiment of the present invention.

EMBODIMENT OF THE INVENTION Hereinafter, the electric compressor by this invention is demonstrated in detail with reference to drawings.

Even if different embodiments, the same or similar reference numerals are given to the same or similar components as the foregoing embodiments, and redundant description thereof will be omitted.

In describing the embodiments disclosed herein, when it is determined that the detailed description of the related known technology may obscure the gist of the embodiments disclosed herein, the detailed description thereof will be omitted.

The accompanying drawings are only for easily understanding the embodiments disclosed in the present specification, and the technical idea disclosed in the present specification is not limited by the accompanying drawings, and all changes and equivalents included in the spirit and scope of the present invention are provided. It should be understood to include water or substitutes.

A singular surface includes a plural expression unless the context clearly indicates otherwise.

The electric compressor according to the present invention may be a scroll compressor in which two scrolls are engaged to compress a refrigerant. The electric compressor according to the present invention may be a component of a refrigeration cycle apparatus for sucking and compressing a refrigerant into a working fluid. In this embodiment, an electric scroll compressor using R-134a as a working fluid will be described as an example.

1 is a cross-sectional view showing the interior of the electric compressor according to the present invention, Figure 2 is a cross-sectional view showing an enlarged portion of the compression unit in FIG.

As shown in Figs. 1 and 2, the low-pressure electric scroll compressor (hereinafter, abbreviated as electric compressor) according to the present embodiment is fixed inside the compressor casing (hereinafter, abbreviated as casing) 101. The frame 102, the drive motor 103, which is an electric motor provided on one side of the frame 102, around the frame 102, and the other side of the frame 102, are used to generate refrigerant by using the rotational force of the drive motor 103. Compressor module 100 consisting of a compression unit 105 for compressing the compressor module 100 is detachably coupled to one side of the compressor module 100 may be made of an inverter module 200 for controlling the rotational speed of the drive motor 103. .

The inverter module 200 is provided to contact a portion constituting the suction space S1 of the compressor casing 101. Accordingly, it is possible to quickly dissipate heat generated from the switching element 220 of the inverter module 200 by the cold refrigerant sucked into the suction space S1.

In addition, the inverter module 200 includes an inverter housing 210 having a predetermined internal volume. At least one switching element 220 for controlling the rotational speed of the driving motor 103 is accommodated in the inverter housing 210.

As the casing 101 is disposed in the transverse direction with respect to the ground, the drive motor 103 and the compression unit 105 are arranged along the transverse direction, for convenience, by designating the left side of FIG. 1 as the front side and the right side as the rear side. Explain.

The casing 101 is coupled to the main housing 111 on which the frame 102, the drive motor 103, and the compression unit 105 are installed, and the rear housing opened at the rear end of the main housing 111. 112). The inlet port 101a is formed in the main housing 111, and the exhaust port 101b is formed in the rear housing 112, and the suction space S1 is formed inside the main housing 111, and inside the rear housing 112. Discharge spaces S2 are formed respectively.

The frame 102 is coupled to the rear opening end of the main housing 111, the first scroll 150 to be described later is fixedly supported on the rear surface of the frame 102, the second scroll 160 to be described later 1 is pivotally supported on the rear surface of the frame 102 so as to pivot between the scroll 150 and the frame 102.

The drive motor 103 may include a stator 131 fixed inside the main housing 111, a rotor 132 positioned inside the stator 131 and rotated by interaction with the stator 131. The rotating shaft 133 is coupled to the rotor 132 and transmits the rotational force of the driving motor 103 to the compression unit 105 while rotating together with the rotor 132.

The compression unit 105 is provided between the fixed scroll (hereinafter referred to as a first scroll) 150 supported by the frame 102 and the frame 102 and the first scroll 150 to rotate the first scroll. It includes a swing scroll (hereinafter referred to as a second scroll) 160 to form two pairs of compression chambers v with the 150. An old dam ring 170 may be provided between the frame 102 and the second scroll 160 to prevent the rotation of the second scroll 160 coupled to the rotation shaft 133.

The first scroll 150 is a fixed scroll side plate portion (hereinafter, fixed hard plate portion) (151) is formed in a substantially disk shape, fixed scroll side wall coupled to the frame side wall portion 122 at the edge of the fixed plate portion 151 A portion (hereinafter, scroll sidewall portion) 152 is formed. A fixed wrap 153 is formed on the front surface of the fixed hard plate portion 151 to form a compression chamber v in engagement with the turning wrap 162 which will be described later, and a rotating shaft 133 to be described later on the rear surface of the fixed hard plate portion 151. The shaft support part 151a which supports the 2nd bearing part 133d of () is formed.

A suction passage 154 is formed at one side of the scroll side wall portion 152 so that the suction space S1 and the suction chamber (unsigned) communicate with each other, and a refrigerant compressed in communication with the discharge chamber at the central portion of the fixed hard plate portion 151. The discharge port 155 is discharged to the discharge space (S2) is formed.

The second scroll 160 has a rotating scroll hard plate portion (hereinafter referred to as a rotating hard plate portion) 161 having a substantially disc shape, and is engaged with the fixed wrap 153 on the front surface of the rotating hard plate portion 161 to compress the chamber (v). The turning wrap 162 is formed.

The pivot wrap 162 may be formed in an involute shape together with the fixed wrap 153, but may also be formed in a non-involute shape.

In the scroll compressor as described above, when power is applied to the driving motor 103, the rotating shaft 133 rotates together with the rotor 132 to transmit rotational force to the second scroll 160, and the second scroll ( 160 is rotated by the Oldham ring (170). Then, the compression chamber (v) is continuously moved toward the center side is reduced in volume.

Then, the coolant flows into the suction space S1 through the inlet 101a, and the coolant introduced into the suction space S1 is formed on the outer circumferential surface of the stator 131 and the inner circumferential surface of the main housing 111. Passed through the gap between the 131 and the rotor 132 is sucked into the compression chamber (v) through the suction flow path (154).

Then, the refrigerant is compressed by the first scroll 150 and the second scroll 160 to be discharged into the discharge space S2. The refrigerant is separated from the oil in the discharge space S2, and the refrigerant is exhaust port 101b. While being discharged to the refrigeration cycle through the oil) is repeated a series of processes are supplied to the compression chamber (v) and each bearing surface through the oil supply passage (Fo) to be described later.

On the other hand, as the scroll compressor according to the present embodiment as described above is installed in the transverse direction, it must be supported at least two or more rotary shafts can be stably supported. To this end, the rotating shaft may be supported on each side with the drive motor in between, or may be supported on one side with respect to the drive motor. In the former case, the length of the compressor is relatively long, while in the latter case, the length of the compressor is shortened.

FIG. 1 disclosed above shows an example of the latter. With reference to this, the oil supply structure of the scroll compressor according to the present embodiment is as follows.

That is, in order to support both ends of the rotating shaft, one end of the rotating shaft penetrating the second scroll 160 is inserted into and supported by the first scroll 150 or further penetrates the first scroll 150 to the rear housing 112. It may be inserted and supported.

Referring back to FIG. 1, the main housing 111 is formed in a cylindrical shape in which the front end is closed, and the rear end is opened to seal the rear housing 112.

The rear housing 112 is coupled to the main housing 111 to seal the inside of the casing 101. A discharge space S2 is formed in the rear housing 112, and an exhaust port 101b described above is formed at one side of the discharge space S2.

An oil separator (not shown) for separating oil from the discharged coolant is provided separately inside the exhaust port 101b or around the exhaust port 101b, or an oil separator is formed without a separate oil separator.

Here, the discharge space (S2) is formed in the upper half of the oil separation unit (S21) for separating the oil from the refrigerant discharged from the compression chamber (v), the oil storage unit for storing the oil separated in the oil separation unit (S21) ( S22) is formed in the lower half. The oil storage part S22 is connected to the compression part 105 through the oil supply passage Fo which will be described later, and the oil of the oil storage part S22 is supplied to the compression part 105 or the rotating shaft 133.

1 and 2, the rotation shaft 133 may be divided into a shaft portion 133a, a first bearing portion 133b, an eccentric portion 133c, and a second bearing portion 133d.

The shaft portion 133a is pressed into and coupled to the rotor core constituting the rotor 132.

The first bearing portion 133b is rotatably coupled through the frame shaft hole 125 to be described later. A first bearing 191 made of a bush bearing is inserted into and coupled to the inner circumferential surface of the frame shaft hole 125, and an outer circumferential surface of the first bearing portion 133b is combined with the inner circumferential surface of the first bearing 191 to have a first radius. It forms a directional bearing surface.

The eccentric portion 133c extends from the first bearing portion 133b toward one end (hereinafter, referred to as a first end) of the rotation shaft 133 so as to be eccentrically formed, and the rotation shaft coupling portion 163 of the second scroll 160 is formed. Combined through. The rotating shaft coupling portion 163 is formed through the center of the turning hard plate portion 161. A second bearing 192 made of a bush bearing is inserted into and coupled to the inner circumferential surface of the rotation shaft coupling portion 163, and an inner circumferential surface of the second bearing 192 forms an outer circumferential surface of the eccentric portion 133c and a third radial bearing surface. Done.

The second bearing portion 133d extends further from the eccentric portion 133c toward the first end portion and is rotatably inserted into the shaft support portion 151a of the first scroll 150. A third bearing 193 made of a bush bearing is inserted into and coupled to the inner circumferential surface of the shaft support part 151a, and the inner circumferential surface of the second bearing 193 has an outer circumferential surface and a second radial bearing surface of the second bearing portion 133d. To form. However, the third bearing 193 is not limited only to the bush bearing. That is, the needle bearing may be applied to the third bearing 193. In the case of the needle bearing can also be used as an axial bearing can be suppressed to a certain degree to the rotary shaft 133 is pushed toward the other end (hereinafter, the second end).

On the other hand, the shaft support portion 151a protrudes toward the rear side, that is, the rear housing 112 from the center of the fixed light plate portion 151 of the first scroll 150. However, the shaft support part 151a may be formed without protruding from the fixed hard plate part 151. However, in this case, the thickness of the fixed hard plate portion 151 may be formed thicker by the depth of the shaft support portion 151a.

In addition, a communication hole 151b is formed in the shaft support part 151a to communicate the internal space of the shaft support part 151a with the oil storage part S22, and the coupling hole 151b is coupled to face the oil storage part S22. The oil supply pipe 141 may be connected. However, the oil supply pipe may be connected to the communication hole 151b without being limited to the oil supply pipe by forming an oil supply groove on the rear surface or the rear housing 112 of the first scroll 150.

On the other hand, the oil passage 142 forming a part of the oil passage (Fo) is formed inside the rotating shaft 133, in the middle of the oil passage 142 a plurality of oil supply holes (142a, 142b, 142c) in the longitudinal direction It is formed at a predetermined interval along the.

The oil passage 142 may be formed up to an intermediate position of the rotation shaft 133. That is, the length or depth of the oil passage 142 should be in communication with both the first oil supply hole 142a and the second oil supply hole 142b, which will be described later, and thus are the eccentric side oil supply holes relatively far from the compression-side end portion of the rotating shaft. It is preferably formed longer than the second oil supply hole 142b.

Here, the first oil supply hole 142a may be formed to overlap an area overlapping the second scroll 150, that is, the first bearing part 133b. In addition, the second oil supply hole 142b may be formed to overlap the compression portion 105, that is, the eccentric portion 133c.

For example, as the second oil supply hole 142b to be described later is formed within the range of the eccentric portion 133c, the oil passage 142 is also an eccentric portion at the compression side side end (or the second bearing side side end) of the rotation shaft 133. It is preferable that it is formed to the range of 133c. Even though the oil flow path 142 is formed deeper beyond the second oil supply hole 142b, the oil is discharged only through the first oil supply hole 142a and the second oil supply hole 142b, so that the oil channel 142 is eccentric. It is not necessary to form deeply to the above. However, when the oil flow path is formed longer as the first bearing part 133b, the weight of the rotating shaft may be reduced to increase the motor efficiency.

The plurality of oil supply holes 142a and 142b are radially penetrated toward the outer circumferential surfaces of the second bearing portion 133d and the eccentric portion 133c so that oil moving through the oil passage 142 is guided to the respective bearing surfaces. Can be. The plurality of oil supply holes 142a and 142b can be formed in the axial range of the second bearing portion 133d and the eccentric portion 133c corresponding to those oil supply holes. The plurality of oil supply holes are based on the movement order of the oil, and the oil supply holes formed in the second bearing portion 133d are the first oil supply holes 142a, and the oil supply holes formed in the eccentric portion 133c are supplied with the second oil supply. It divides into the hole 142b.

As described above, the frame 102 is positioned between the driving motor 103 and the compression unit 105 to support the second scroll 160 in the axial direction. In addition, the frame 102 has a frame plate 121 formed in a disk shape. The frame side wall portion 122 coupled to the side wall portion 152 of the first scroll 150 is formed at the rear edge of the frame plate portion 121, and the back pressure space ( S3) is formed. In addition, a frame thrust surface on which the second scroll 160 is mounted and supported in the axial direction is formed inside the frame side wall portion 122.

Here, the back pressure space (S3) is a space formed between the rear surface of the frame 102 and the turning hard plate portion 161 of the second scroll 160 facing the frame 102, and communicates with the variable back pressure unit 180 to be described later. It is formed to be. For this reason, the back pressure space S3 is communicated with the compression chamber v through the variable back pressure unit 180 so that the refrigerant or oil is converted into the back pressure space according to the pressure difference between the pressure of the back pressure space S3 and the pressure of the compression chamber v. It moves between S3) and the compression chamber v. Therefore, the pressure of the back pressure space S3 forms an intermediate pressure between the pressure of the suction space S1 and the final pressure (that is, the discharge pressure) of the compression chamber v, and by the back pressure of the back pressure space S3. The back of the second scroll 160 is supported.

The frame shaft hole 125 described above is formed at the center of the frame 102 constituting the back pressure space S3, and the outer circumferential surface of the rotation shaft 133 is precisely formed on the inner circumferential surface of the frame shaft hole 125. The first bearing 191 forming the first radial bearing surface B1 may be inserted and coupled between the outer circumferential surface of 133b.

In addition, the frame 102 may be provided with a sealing member for sealing the back pressure space (S3). The sealing member may include a hard disk sealing member 123 disposed between the frame 102 and the first scroll 150 and a shaft sealing member 1234 provided at the front side of the frame 102.

The hard plate sealing member 123 is disposed between the frame side wall portion 122 and the side wall portion 152 of the first scroll 150. The hard plate sealing member 123 may be formed in a ring shape having a predetermined width. At least a portion of the hard plate sealing member 123 may be disposed between the first scroll 150 and the second scroll 160 to seal the compression chamber v.

The shaft sealing member 1234 is provided at the front side of the frame 102 and is disposed to prevent a gap between the rotation shaft 133 and the frame 102. More specifically, the frame 102 is formed with a central wall portion 126 protruding toward the front side from the central portion through which the rotation shaft 133 penetrates to increase the area supporting the rotation shaft 133 in the radial direction. The center wall part 126 is formed to surround the rotation shaft 133, and as described above, the first bearing part 133 b is disposed between the center wall part 126 and the rotation shaft 133. The shaft sealing member 124 is disposed at the front end portion of the center wall portion 126. The shaft sealing member 124 is formed to surround the rotating shaft, it may be provided with an O-ring member.

The back pressure space S3 is maintained in the sealed state by the hard plate sealing member 123 and the shaft sealing member 124, and the back pressure change due to leakage can be minimized.

On the other hand, such a scroll compressor requires a different back pressure depending on the drive speed of the compressor. More specifically, at a high driving speed, the specific gravity of the loss due to friction between the first scroll 150 and the second scroll 160 increases, so that a relatively low back pressure is required.

On the other hand, at low driving speeds, the loss due to the refrigerant leaking through the gap between the first scroll 150 and the second scroll 160 increases rather than the friction between the first scroll 150 and the swing scroll 160. Therefore, high back pressure is required. Accordingly, the present invention includes a variable back pressure unit 180 so that different back pressures can be formed according to the driving speed.

Hereinafter, the variable back pressure unit 180 according to the present invention will be described in detail.

As described above, the second scroll 160 may include a variable back pressure unit 180 formed in the pivot plate 161. The variable back pressure unit 180 forms a plurality of back pressure passages connecting the compression chamber v and the back pressure space S3.

According to the driving speed of the second scroll 160, that is, the speed at which the second scroll 160 rotates on the first scroll 150, the variable back pressure unit 180 controls the back pressure of the compression chamber v and the back pressure. It may be formed to connect the space (S3).

In detail, the variable back pressure unit 180 may include first and second back pressure passages. In this case, the first and second back pressure flow paths communicate with different positions of the compression chamber v, and the compression chamber v and the second back pressure flow path are connected to each other according to the turning speed of the second scroll. The back pressure space S3 may be in communication.

In this case, since the first and second back pressure flow passages communicate portions having different pressures in the compression chamber v and the back pressure space S3, respectively, different back pressures may be formed in the back pressure space S3.

3 is a perspective view of a second scroll according to the present invention, and FIG. 4 is a cross-sectional view taken along A of the second scroll shown in FIG. 3.

Referring to these drawings in conjunction with FIGS. 1 and 2, the variable back pressure unit 180 may include a variable back pressure chamber 181, a mass body 183, and an elastic member 184.

The variable back pressure chamber 181 is formed in the turning hard plate portion 161 of the second scroll 160. The variable back pressure chamber 181 may be formed as a cylindrical space. The variable back pressure chamber 181 is formed to extend in the direction of the center of the second scroll 160 in a circular cross section.

The variable back pressure chamber 181 may be formed by covering the cover 188 after cutting such as turning scroll drill processing, end mill processing, and reamer processing from the outer circumferential surface of the second scroll 160 to the center direction. have.

The variable back pressure chamber 181 may include a first surface 181a and a second surface 181b facing each other, and a third surface 181c connecting the first surface 181a and the second surface 181b to each other. have. The first surface 181a and the second surface 181b correspond to each end of the variable back pressure chamber 181 which is circular. Here, the second surface 181b may correspond to one surface of the cover 188, and the third surface 181c may correspond to the circumferential surface of the variable back pressure chamber 181.

Meanwhile, first to third holes 182a, 182b, and 182c communicating the compression chamber v and the back pressure space S3 may be formed in the second surface 181b. In other words, it may be formed so as to penetrate one surface and the other surface of the turning plate 161, respectively.

The first hole 182a and the second hole 182b may be formed to penetrate the surface facing the first scroll 150 of the turning plate 161 to communicate the compression chamber v and the variable back pressure chamber. . In addition, the third hole 182c is formed to penetrate the surface facing the frame 102 of the turning plate 161 to communicate with the back pressure space S3 and the variable back pressure chamber 181.

Here, the first hole 182a and the second hole 182b are disposed along the radial direction of the second scroll 160 so as to communicate with portions having different pressures of the compression chamber v. The first hole 182a and the second hole 182b may be formed closer to the center of the turning scroll than the second hole 182b.

According to the present invention, the first hole 182a and the second hole 182b may be formed with the turning scrap 162 interposed between the turning hard plate portions 161. The first hole 182a and the second hole 182b may communicate with portions having different pressures in the same compression chamber v, respectively. Thus, the pressure of the refrigerant flowing in the first hole 182a may be greater than the pressure of the refrigerant flowing in the second hole 182b.

Alternatively, the first hole 182 and the second hole 182b may be formed such that the fixing scrap 153 is disposed therebetween. In this case, the first hole 182a and the second hole 182b may communicate with different compression chambers v. However, the present invention is not limited thereto, and positions of the first holes 182a and the second holes 182b may be determined through proper design according to the required back pressure.

In the first and second holes 182a and 182b, a state in which the first and second holes 182a and 182b communicate with the compression chamber v and a blocked state may be repeated according to the turning motion of the second scroll 160. To this end, the variable back pressure chamber 181 is provided with a mass body 183 and the elastic member 184.

The mass body 183 is provided to be slidably movable in the variable back pressure chamber 181. The mass body 183 may have a cylindrical shape in which the outer circumferential surface is stepped. The length of the mass body 183 may be formed to be smaller than the length extending in the radial direction of the variable back pressure chamber 181 to be able to slide in the variable back pressure chamber (181).

5A is a perspective view of a mass according to an embodiment of the present invention, and FIGS. 5B and 5C are perspective views of a mass according to another embodiment of the present invention.

Referring to the drawing, the mass body 183 includes a first portion 183a and a second portion 183b. The first portion 183a is formed smaller than the diameter of the variable back pressure chamber 181 so that the first to third holes 182a, 182b, and 182c may be formed in the compression chamber v or the back pressure space S3 and the variable back pressure chamber 181. ) Can be communicated.

The second portion 183b is provided at both ends of the first portion 183a to block the first hole 182a or the second hole 182b. The diameter of the second portion 183b may be formed to be substantially the same as or smaller than the diameter of the variable back pressure chamber.

Here, the length of the first portion 183a may be smaller than the distance between the first hole 182a and the second hole 182b. As a result, the first and second holes 182a and 182b may be both blocked by the second portion 183b, or one of the first and second holes 182a and 182b may be blocked.

Referring to FIG. 5A, the first portion 183a may have a cylindrical shape having a diameter smaller than the diameter of the second portion 183b.

However, the present invention is not limited thereto, and the first portion may have the same diameter as the second diameter, and may be formed to decrease in diameter toward the center. Referring to FIG. 5B, the first portion 283a may be formed to be inclined along the center. Alternatively, referring to FIG. 5C, the first portion 383a may be formed to have a concave curved surface toward the center.

On the other hand, the variable back pressure chamber 181 is provided with an elastic member 184 for applying an elastic force to the mass body 183. The elastic member 184 may be formed of a coil spring. The elastic member 184 may be disposed between the mass body 183 and the second surface 182b of the variable back pressure chamber 181 to apply an elastic force to the mass body 183 in the direction of the center of the second scroll 160. .

Hereinafter, a mechanism for forming different back pressures according to the driving conditions of the compressor will be described.

The mass body 183 disposed in the variable back pressure chamber 181 is the second scroll 160 in the variable back pressure chamber 181 by the centrifugal force generated by the driving of the second scroll and the elastic force of the elastic member 184. The slide can move in the radial direction.

Therefore, the mass body 183 may be positioned to communicate the first hole 182a and the third hole 182c or to communicate the second hole 182b and the third hole 182c. Here, the flow path leading through the first hole 182a and the third hole 182c may be referred to as a first back pressure flow path, and the flow path leading through the second hole 182b and the third hole 182c may be referred to as a second back pressure flow path.

As described above, the position of the mass body 183 is determined by the centrifugal force and the elastic force and the force of the elastic member 184 according to the pivoting motion of the second scroll 160. Here, the second scroll 160 is a rotational movement, not a rotational movement, but from the viewpoint of the mass body 183, the same effect as the rotational movement around a certain point is generated. For this reason, the mass body 183 receives the centrifugal force in the radial direction of the second scroll 160 in accordance with the turning motion of the second scroll 160.

In more detail, when the second scroll 160 is stopped, the mass body 183 is positioned in a state inclined toward the center of the second scroll 160 by the elastic force of the elastic member 184. At this time, when the second scroll 160 is pivoting, the centrifugal force is applied to the mass body 183 in the radial direction of the second scroll 160 to form a balance point with the elastic force of the elastic member 184. It is located at a point moved by a certain distance in the radial direction.

Here, when the rotational movement speed of the second scroll 160 is less than the preset speed, the second portion 183b of the mass body 183 covers the second hole 183b, and the first portion of the mass body 183 ( 183a faces the first hole 182a. In this case, the compression chamber v and the back pressure space S3 communicate with each other by the first hole 182a, the variable back pressure chamber 181, and the third hole 182c. In other words, the compression chamber v and the back pressure space S3 are connected by the first back pressure flow path so that a relatively high pressure can be applied to the back pressure space S3.

On the other hand, when the rotational movement speed of the second scroll 160 is increased above the predetermined speed, the centrifugal force of the mass body 183 is increased to be positioned in the radial direction of the second scroll 160. In this case, the second portion 183b of the mass body 183 covers the first hole 182a, and the first portion 183a of the mass body 183 faces the second hole 182b. In this case, the compression chamber v and the back pressure space S3 are connected by the second hole 182b, the variable back pressure chamber 181, and the third hole 182c. That is, the back pressure space S3 may be connected to the compression chamber v in which a relatively low pressure is formed by the second back pressure flow path, thereby forming a relatively low back pressure.

Here, since the third hole 183c is disposed between the first hole 182a and the second hole 183b, the third hole 183c may not be covered by the mass body 183. Therefore, the state in which the variable back pressure chamber 181 and the back pressure space S3 are communicated can be maintained.

However, since the second scroll 160 does not rotate, even when driven at a constant speed, the same centrifugal force is not continuously applied to the mass body 183. That is, the state to which centrifugal force is applied and the state to which no centrifugal force is applied are repeated.

When the second scroll 160 pivots at a relatively low speed, the elastic force by the elastic member 184 is greater than the centrifugal force applied to the mass body 183 so that the mass body 183 is the center of the second scroll 160. The first hole 182a is communicated or the first hole 182a is covered in the biased direction. However, even in this case, since the second hole 182b is kept in a hidden state, the high pressure back pressure can be maintained relatively to the back pressure space S3.

On the contrary, when the second scroll 160 pivots at a high speed, the centrifugal force applied to the mass body is greater than the elastic force of the elastic member 184, so that the mass body 183 faces the outer circumferential surface of the second scroll 160. In the biased state, the second hole 182b communicates with each other, or the operation of covering the second hole 182b is repeated. In this case, since the first hole 182a is maintained in a hidden state, and the third hole 182c continues to communicate, the low pressure back pressure can be maintained relatively to the back pressure space S3.

According to this mechanism, the variable back pressure unit 180 can form another back pressure in the back pressure space S3 according to the driving speed.

FIG. 6 is a perspective view of a second scroll according to another embodiment of the present invention, FIG. 7A is a cross-sectional view taken along B of the second scroll shown in FIG. 6, and FIG. 7B is a view of the second scroll shown in FIG. 6. Sectional drawing cut in accordance with C.

Referring to the drawings, the variable back pressure unit 180 may be provided in plural along the circumferential direction of the second scroll 160. In this case, the variable back pressure unit 180 may be disposed so as not to overlap with a portion in which the key portion of the old dam ring 170 and the key groove coupled with the key portion are formed.

In addition, the plurality of variable back pressure units 180 may be symmetrically disposed with respect to the center of the second scroll 160 so that the center of mass of the second scroll 160 is not eccentric. In this case, the variable back pressure units 180 arranged symmetrically with respect to the center of the second scroll by the turning motion of the second scroll 160 have a phase difference of 180 degrees with each other.

For example, when the second scroll 160 rotates at a high speed, the mass body 183 of the variable back pressure unit 180 disposed at one side may be positioned to communicate the second hole 182b at one point. In this case, the mass body 183 of the variable back pressure unit 180 disposed on the opposite side to the variable back pressure unit 180 disposed on one side may be positioned to cover the second hole 182b. Thus, despite the turning movement of the second scroll 160, the constant back pressure can be maintained continuously in the back pressure space (S3).

Meanwhile, as described above, the oil passage 142 and the plurality of oil supply holes 142a, 142b, and 142c are formed in the rotation shaft 133. It is supplied to the 1st bearing part 133b, the eccentric part 133c, and the 2nd bearing part 133d through the oil supply hole 142a, 142b, 142c.

Meanwhile, oils supplied to the first bearing part 133b and the eccentric part 133c may flow into the back pressure space S3. In addition, the oil introduced into the back pressure space S3 may be supplied to the compression chamber v through the first and second back pressure passages.

That is, the first and second back pressure passages may be utilized as oil supply passages. In this case, the oil can flow into the compression chamber v to lubricate the fixed scroll and the swing scroll, as well as at least a part to lubricate between the mass and the variable back pressure chamber.

8 illustrates a variable back pressure unit 280 according to another embodiment of the present invention.

Referring to the drawings, the elastic member 284 may include first and second elastic members 284a and 284b. The first and second elastic members 284a and 284b may be disposed to face each other with a mass therebetween in the variable back pressure chamber. That is, the first elastic member 284a may be disposed between the first surface 281a and the mass 283, and the second elastic member 284b may be disposed between the second surface 281b and the mass 283. have.

In this case, the first elastic member 284a exerts an elastic force on the mass 283 in the radial direction of the second scroll 160, and the second elastic member 284b is applied to the mass 283 of the second scroll 60. The elastic force is applied in the center direction. That is, the variable back pressure unit 280 may be formed by sequentially inserting the first elastic member 284a, the mass body 283, and the second elastic member 284b into the variable back pressure chamber 281.

Meanwhile, the first and second elastic members 284a and 284b may have different elastic modulus. In this case, the synthetic elastic modulus can be easily adjusted when designing the variable back pressure unit 280 through the first and second elastic members 284a and 284b having different elastic modulus. In addition, durability may be improved by preventing collision between the mass 283 and the first surface 281a.

What has been described above are only embodiments for implementing the electric compressor according to the present invention, and the present invention is not limited to the above embodiments, and does not depart from the gist of the present invention as claimed in the following claims. Anyone with ordinary knowledge in the field to which the present invention belongs will have the technical idea of the present invention to the extent that various modifications can be made.

Claims (15)

A first scroll having a fixed wrap;
A second scroll having a swing wrap that forms a compression chamber between the first scroll and a pivot plate portion for supporting the swing wrap while pivoting in engagement with the fixed wrap;
A frame having a back pressure space formed between the second scroll and the second scroll supported by the pressure in the back pressure space in a direction toward the first scroll; And
It includes a variable back pressure unit formed in the hard plate portion,
The variable back pressure unit forms first and second back pressure flow paths connecting the compression chamber and the back pressure space,
The first and second back pressure flow passages communicate with the compression chamber having different pressures,
And the compression chamber communicates with the back pressure space through the first back pressure passage or the second back pressure passage according to the turning speed of the second scroll. The method of claim 1,
The variable back pressure unit,
A variable back pressure chamber defining a space in the hard plate part;
A mass body provided to be movable in the variable back pressure chamber; And
An elastic member for elastically supporting the mass in the direction of the center of the hard plate portion,
The mass has a first position in which the first back pressure flow path is opened and the second back pressure flow path is closed by the centrifugal force of the mass and the inertia force of the elastic member, and the second back pressure flow path is closed and the second back pressure flow path is opened. Wherein the compressor is moved between positions. The method of claim 2,
The hard plate portion,
First and second holes formed through the surface facing the first scroll to communicate the compression chamber with the variable back pressure chamber; And
A third hole formed to penetrate a surface facing the frame to communicate the variable back pressure chamber with the back pressure space;
The first back pressure flow passage includes the first hole and the third hole,
And the second back pressure passage includes the second hole and the third hole. The method of claim 3,
The first hole and the second hole is disposed along the radial direction, characterized in that spaced apart in the radial direction with the pivot wrap therebetween. The method of claim 3,
And the third hole is disposed between the first hole and the second hole. The method of claim 3,
And when one of the first and second holes is in communication with the third hole, the other is blocked by the mass. The method of claim 2,
The variable back pressure chamber extends in the radial direction of the hard plate portion,
And the mass is formed to be smaller than the radial length of the variable back pressure chamber. The method of claim 8,
The mass is
A first portion having a cross section smaller than a diameter of the variable back pressure chamber so as to form first and second back pressure passages; And
And a second portion provided at both sides of the first portion and having a cross section corresponding to a diameter of the variable back pressure chamber. The method of claim 9,
And the radial length of the first portion is less than the distance between the first and second holes. The method of claim 1,
The variable back pressure unit is provided with a plurality in the circumferential direction of the second scroll. The method of claim 10,
And the variable back pressure units are arranged symmetrically with respect to the center of the second scroll. The method of claim 1,
A rotation shaft coupled to the second scroll to transmit a rotational force of the transmission unit;
And the rotating shaft is coupled through the frame, the second scroll, and the first scroll sequentially. The method of claim 12,
The rotation axis is,
An oil passage extending in the axial direction therein; And
A plurality of oil supply holes communicating with the oil passage and extending radially and communicating with the frame, the second scroll and the bearing surface between the first scroll and the rotating shaft,
And the plurality of oil supply passages communicate with the back pressure space. A compression chamber formed between the first scroll and the second scroll, the compression chamber compressing the fluid by reducing the volume while moving from the outside to the inside;
A back pressure space formed between the second scroll and the frame supporting the second scroll and supporting the second scroll toward the first scroll; And
A variable back pressure chamber formed inside the second scroll to be disposed between the compression chamber and the back pressure space;
The variable back pressure chamber includes a plurality of back pressure passages communicating with different positions of the compression chamber.
And the compression chamber communicates with the back pressure space by any one of a plurality of back pressure passages according to the driving speed of the second scroll. The method of claim 14,
The second scroll is formed with a key groove coupled to the key portion of the Oldham ring,
The variable back pressure chamber is an electric compressor, characterized in that formed at a predetermined interval in the circumferential direction with the key groove.

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