KR20190083565A - Motor-operated compressor - Google Patents

Abstract

A motor-driven compressor according to the present invention comprises: a casing receiving a rotating shaft; a main frame rotatably supporting the rotating shaft; and a compression unit including a first scroll positioned to be fixed to the casing and a second scroll connected to the rotating shaft to rotate in engagement with the first scroll. The main frame includes: a bearing unit formed to surround the rotating shaft; a back pressure space configured to receive a fluid which pressurizes the second scroll toward the first scroll; and a shaft seal inserted between the bearing unit and the rotating shaft to seal the back pressure space and having an oil hole communicating with the back pressure space. Thus, it is possible to reduce wear on a sealing member caused by rotation of the rotating shaft and to improve efficiency of the compressor.

Description

[0001] MOTOR-OPERATED COMPRESSOR [0002]

The present invention relates to a compressor, and more particularly to an electric compressor applied to a 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. In the scroll type electric compressor, a motor unit constituted by a rotary motor is provided inside a closed casing, and a compression unit including a fixed scroll and an orbiting scroll is provided on one side of the motor unit. The motor portion and the compression portion are connected to each other by a rotation shaft, and the rotational force of the motor portion is transmitted to the compression portion. The rotating force transmitted to the compression section causes the orbiting scroll to pivot relative to the fixed scroll to form two pairs of compression chambers formed of a suction chamber, an intermediate pressure chamber, and a discharge chamber. The refrigerant is sucked into both compression chambers, do.

In the scroll compression method, a back pressure space is formed to pressurize the orbiting scroll so as to be brought into close contact with the fixed scroll, thereby maintaining the closed state of the compression chamber. Normally, the back pressure space is formed to communicate with the intermediate pressure chamber or the discharge pressure chamber. As a result, the back pressure space accommodates the refrigerant of the intermediate pressure or the discharge pressure and presses the orbiting scroll in the direction toward the fixed scroll.

Further, seal structures sealing the back pressure space may be formed to maintain an appropriate pressure in the back pressure space. Among them, a structure in which a seal structure is inserted between a rotary shaft and a frame as in Patent Document 1 has been disclosed as a prior art.

Since the seal structure between the rotary shaft and the frame is made to achieve sealing of the contact surfaces between the rotating shaft and the fixed frame structure which are rotated when the compressor is driven, a large frictional force is generated. The frictional force acts as a friction torque on the rotary shaft and acts as an increase in power consumption for driving the rotary shaft.

In particular, the seal structure between the rotary shaft and the frame can be designed to have a structure in which the pressure for sealing the contact surface increases as the pressure in the back pressure space increases. In addition, the back pressure space may be communicated with the discharge space or the oil separator so as to have the discharge pressure. In such a design, as the discharge pressure is increased, the pressure in the back pressure space is also increased, and accordingly, the seal structure is brought into strong contact with the rotary shaft or the frame, resulting in an increase in friction torque and an increase in power consumption.

Therefore, it is required that the seal structure of the back pressure space is provided with a design factor so as to reduce the frictional torque when the rotary shaft is driven while performing the sealing function. Particularly, it is desirable that a method capable of realizing a proper sealing condition and a friction reduction without adding a complicated structure or apparatus is desirable.

US 20140134032 A1 (2014.05.14 open)

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electric compressor including a shaft seal which is capable of being supplied with oil onto surfaces that are in contact with the rotating shaft or the frame to seal the back pressure space.

Still another object of the present invention is to provide an electric compressor in which a hole for supplying oil is easily machined and a smooth oil supply path can be ensured even when the shaft seal is deformed.

According to an aspect of the present invention, there is provided an electric compressor according to the present invention, comprising: a casing accommodating a rotary shaft; A main frame rotatably supporting the rotation shaft; And a compression unit including a first scroll positioned to be fixed to the casing and a second scroll connected to the rotation axis and engaged with the first scroll, wherein the main frame is formed to surround the rotation axis Axis bearing; A back pressure space formed to receive fluid that presses said second scroll toward said first scroll; And a shaft seal inserted between the bearing water portion and the rotary shaft to seal the back pressure space and having an oil hole communicating with the back pressure space.

In order to accomplish another object of the present invention, the bearing portion of the motor-driven compressor according to the present invention is provided with a seal receiving recessed portion, which is recessed on a surface facing the back pressure space and positioned adjacent to an outer peripheral surface of the rotary shaft, Wherein the shaft seal comprises: a first friction portion adapted to contact an outer peripheral surface of the rotary shaft; And a second frictional portion formed to be in contact with a bottom surface of the seal receiving groove and formed with an end of the oil hole.

According to the present invention constituted by the solution means described above, the following effects can be obtained.

In the present invention, oil holes are formed in the shaft seal, so that oil can be uniformly supplied to the surface of the shaft seal. In particular, since oil can be supplied to the friction surface of the shaft seal contacting the shaft bearing portion or the rotation shaft, friction between the shaft seal and the rotation shaft or friction between the shaft seal and the shaft bearing portion due to driving of the rotation shaft can be alleviated. Therefore, the power consumption of the rotary shaft can be reduced without significantly lowering the closed state of the back pressure space.

Further, in the present invention, the end of the oil hole may be located on the bottom surface of the seal receiving groove. By positioning the end of the oil hole in the direction parallel to the insertion direction of the shaft seal, the shape of the oil hole and the deformation of the diameter can be minimized even if the shaft seal is fitted while being deformed in the assembling process. As a result, the reliability of the operation of supplying oil to the friction surfaces of the oil hole can be ensured.

1 is a sectional view showing an electric compressor according to an embodiment of the present invention;
2 is an enlarged view of a region A shown in Fig.
3 is a perspective view showing a part of the shaft seal shown in Fig. 2; Fig.
4 is a view showing a shaft seal of an electric compressor according to another embodiment of the present invention.
5 is a perspective view showing a part of the shaft seal shown in Fig. 4; Fig.
6 is a view showing a shaft seal of an electric compressor according to another embodiment of the present invention.
FIG. 7 is a perspective view showing a part of the shaft seal shown in FIG. 6; FIG.

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

In other respects, the same or similar reference numerals are given to the same or similar components to those of the previous embodiment, and a duplicate description thereof will be omitted.

In the following description of the embodiments of the present invention, a detailed description of known related arts will be omitted when it is determined that the gist of the embodiments disclosed in the present specification may be obscured.

It is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention, It should be understood that it includes water and alternatives.

The singular expressions include plural expressions unless the context clearly dictates otherwise.

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 the present embodiment, an electric scroll compressor using R-134a as a working fluid will be described as an example. 1 is a cross-sectional view illustrating an electric compressor 100 according to an embodiment of the present invention.

Referring to FIG. 1, an electric compressor 100 according to an embodiment of the present invention includes a casing 101, a main frame 102, a drive unit 103, and a compression unit 104. The overall positional relationship between them is that the main frame 102 is fixed to the middle of the inner wall of the casing 101 and the drive unit 103 for generating a driving force on one side (front side) of the main frame 102 Can be installed. A compression unit 104, which receives the driving force of the driving unit 103 and compresses the refrigerant, may be installed on the other side (rear side) of the main frame 102.

In addition, a control unit (not shown) 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. [

As shown in FIG. 1, the casing 101 may include a front cover 111 and a rear cover 112. The front cover 111 is formed in a cylindrical shape having a rear opening, and may be configured to receive the drive unit 103 and form a suction space S1 therein. The rear cover 112 may be coupled to cover the rear of the front cover 111. [ The rear cover 112 is formed in a cylindrical shape having a front opening and can be formed to receive the compression unit 104.

Here, the suction space S1 can be separated into the first space S11 and the second space S12 by the drive unit 103 housed therein. The first space S11 and the second space S12 are connected to each other through a plurality of communication flow paths 113 formed between the outer circumferential surface of the stator 131 provided in the drive unit 103 and the inner circumferential surface of the front cover 111 Can be communicated. The refrigerant is sucked into the first space S11 on the side of the front cover 111 and then moved to the second space S12 on the side of the main frame 102 through the drive unit 103. [

The front cover 111 may be formed with a suction port 114 through which a suction pipe is connected to allow the refrigerant to flow into the suction space S1. The suction port 114 can be formed 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 casing 101 through the suction 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 112 may have a discharge port 115 through which the discharge pipe is connected to guide the refrigerant compressed by the compression unit 104 to the refrigeration cycle. The compression unit 104 may be mounted inside the rear cover 112 and the discharge space S2 communicated with the discharge port 115 may be provided at the rear of the compression unit 104. [ The oil separator 116 separating the oil from the discharged refrigerant may be formed in the path from the discharge space S2 to the discharge port 115. [

The driving unit 103 includes a stator 131 and a rotor 132 and serves to drive the rotating shaft 135. [ In this embodiment, the stator 131 is fixed to the inner circumferential surface of the front cover 111 and can be annular so as 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 of the rotor 132. When power is supplied to the drive unit 103, the rotor 132 and the rotary shaft 135 can be rotated together by the interaction of the stator 131 and the rotor 132. [

The rotation shaft 135 can be rotatably supported by the casing 101 and the main frame 102. The front end of the rotary shaft 135 is supported in the radial direction by a sub bearing 162 mounted on the inner surface of the front cover 111 . 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 102. 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 with respect to the first scroll 140, , The intermediate pressure chamber, and the discharge chamber.

The first scroll 140 includes a fixed side end plate 141 formed in a disk shape and a fixed side wall portion 142 projecting toward the main frame 102 on one side of the fixed side end plate 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 from the center of the fixed side rigid plate 141.

A suction port (not shown) communicating with the suction space S1 of the casing 101 is formed at the edge of the fixed side long plate portion 141 and a discharge port A discharge hole communicating with the discharge port S2 may 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 A turning orbiting wrap 152 is formed. The other side surface of the revolving-side fixed plate 151 may be coupled with the rotation shaft 135 via the eccentric bearing 163 and the balance weight 136 to receive the rotational force. Here, the balance weight 136 may function to compensate for the imbalance due to the eccentric motion of the second scroll 150.

Meanwhile, the main frame 102 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 bearing unit 122 can support the rotation shaft 135 through the main bearing 161. [ The main bearing portion 122 may be configured to surround the outer peripheral surface of the rotation shaft 135 at the central portion of the body portion 121 and the main bearing 161 may be coupled to the bearing portion 122. [

In addition, the main frame 102 of the present embodiment may further include a thrust plate 123 and a back pressure space 124. The thrust plate 123 may be coupled to a surface of the main frame 102 facing the second scroll 150 and may form a thrust surface 123a contacting the second scroll 150.

The back pressure space 124 supports the second scroll 150 by the pressure of the refrigerant or the oil accommodated therein and prevents the compression of the compression chamber P formed between the first scroll 140 and the second scroll 150 And the like. The back pressure space 124 may be a space formed by recessing the second scroll 150 at the central portion of the body portion 121 as shown in the drawing. The back pressure space 124 communicates with a recovery space (not shown) in which the oil separated by the oil separator 116 described above is stored, so that a pressure capable of pressurizing the second scroll 150 is supplied by the high pressure oil . The back pressure space 124 and the recovery space can be communicated by the back cover 112, the first scroll 140, and the back pressure passage 117 formed to penetrate the main frame 102. The back pressure space 124 is provided so as to fix the main bearing 161 described above, and the balance weight 136 can be received and rotated.

Further, the main frame 102 may include a thrust seal 125 and a shaft seal 126 for sealing the back pressure space 124. The thrust seal 125 may be interposed between the thrust surface 123a and the thrust plate 123 and the body 121, respectively. The thrust seal 125 is formed of a ring-shaped groove extending in the circumferential direction with reference to an extension line of the rotary shaft 135 or its central axis and a ring member inserted in the groove, for example, an O-ring .

The shaft seal 126 is interposed between the bearing portion 122 and the rotary shaft 135 to function to restrict the fluid in the back pressure space 124 from flowing out between the rotary shaft 135 and the bearing water portion 122. The specific structure and function of the shaft seal 126 provided in the electric compressor 100 according to the present invention will be described later.

A plurality of pins 171 and a recess ring 172 may be provided between the main frame 102 and the turnable side plate 151 to prevent rotation. In this embodiment, the annular recess rings 172 may be respectively inserted into a plurality of spaces which are recessed at the surface of the turnable side plate portion 151 of the second scroll 150. A plurality of pins 171 passing through the thrust plate 123 and fixed to the body 121 are seated in the recess ring 172 and are slidably engaged with the inner peripheral surface of the recess ring 172 . When the rotational force of the rotating shaft 135 is transmitted to the second scroll 150, the second scroll 150 is prevented from rotating by the pin 171 and the recess ring 172, Can be exercised.

The electric compressor 100 according to the present invention described above 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 rotation shaft 135 is pivoted by the eccentric distance by the pin 171 and the recess ring 172 and the compression chamber P is rotated by the rotation shaft 135 The volume is decreased while being continuously moved toward the center side in the radial direction.

Accordingly, the refrigerant flows into the first space S11 through the inlet 114. [ The refrigerant flowing into the first space S11 flows into the second space S12 through the gap between the communication passage 113 or the stator 131 and the rotor 132. [ 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 moving toward the center side along the movement path of the compression chamber P, and is discharged through the discharge hole to the discharge space formed between the first scroll 140 and the rear cover 112 (S2).

The refrigerant discharged into the discharge space S2 is separated from the oil in the discharge space S2 or 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 can remain in the recovery space of the oil separation portion, and the high-pressure oil remaining in the recovery space can be moved to the back pressure space 124 along the back pressure passage 117 to provide back pressure.

The overall structure and operation of the electric compressor 100 according to the present invention have been described above. Hereinafter, the structure and function of the shaft seal 126 will be described in detail according to each embodiment of the present invention.

Fig. 2 is an enlarged view of the area A shown in Fig. 1, and Fig. 3 is a perspective view showing a part of the shaft seal 126 shown in Fig. 1 to 3, the main frame 102 of the electric compressor 100 according to an embodiment of the present invention may further include a shaft seal 126.

Like the prior thrust seal 125, the shaft seal 126 can serve to seal the back pressure space 124. In particular, the shaft seal 126 may be configured to restrict leakage of the fluid (refrigerant or oil) in the back pressure space 124 into the suction space S1 into the space between the rotary shaft 135 and the bearing water portion 122.

Specifically, the shaft seal 126 may be formed in a ring shape inserted between the shaft receiving portion 122 and the rotary shaft 135. In the present embodiment, the shaft seal 126 may be a rectangular seal whose cross section in the radial direction is a quadrangular shape with one corner chamfered. The shaft seal 126 may be formed to be in contact with the surfaces of the rotary shaft 135 and the bearing water portion 122, respectively. The sealing state of the back pressure space 124 can be maintained by sliding the rotating shaft 135 according to the operation of the compressor with at least one of the surfaces of the rotating shaft 135 and the bearing water portion 122.

In addition, a stop ring 127 may be provided as shown to prevent the shaft seal 126 from being disengaged between the bearing 122 and the rotary shaft 135. That is, the stop ring 127 can restrain the shaft seal 126 from being moved in the axial direction of the rotation shaft 135. The stop ring 127 may be formed of a C-ring so that it can be assembled and fixed to the inner surface of the shaft receiving portion 122 after the shaft seal 126 is inserted.

In the electric compressor 100 according to the present invention, as the rotation speed of the rotation shaft 135 increases, the friction between the shaft seal 126 and the bearing water 122 or between the shaft seal 126 and the rotation shaft 135 The resistance becomes large. Frictional resistance is inevitable for sealing the contact surface of the shaft seal 126. However, if the friction torque acting on the rotary shaft 135 is increased, the mechanical efficiency of the compressor may be lowered.

In addition, as the electric compressor 100 according to the present invention operates at a high compression ratio, the fluid pressure in the discharge space S2 rises and the hydraulic pressure in the back pressure space 124 communicating with the discharge space S2 also increases. The increase in the hydraulic pressure in the back pressure space 124 may be a situation in which the shaft seal 126 presses the contact surfaces more strongly so that the friction torque is further increased.

In order to reduce frictional losses generated at the contact surfaces of the shaft seal 126, the shaft seal 126 may include an oil hole 126a in an embodiment of the present invention. The oil hole 126a is communicated with the back pressure space 124 so that the oil in the back pressure space 124 can be supplied to the surface of the shaft seal 126. Specifically, one end of the oil hole 126a is exposed toward the back pressure space 124, and the other end of the oil hole 126a is positioned to pass through the surface abutting the rotation shaft 135 or the bearing water portion 122, And may be positioned to abut the rotary shaft 135 or the bearing portion 122.

When the oil hole 126a is formed in the shaft seal 126 according to the present invention, not only the surface of the shaft seal 126 exposed in the back pressure space 124 but also the surface of the shaft seal 126 exposed to the bearing water portion 122 or the rotating shaft 135 So that oil can be evenly supplied to the surface of the shaft seal 126. As a result, the friction between the shaft seal 126 and the rotary shaft 135 or the friction between the shaft seal 126 and the bearing water 122 due to the rotation of the rotary shaft 135 can be alleviated and the friction applied to the rotary shaft 135 The reduction in torque and the improvement in mechanical efficiency can be realized. At this time, the other end of the oil hole 126a comes into contact with the surface of the bearing portion 122 or the rotating shaft 135, so that the oil in the back pressure space 124 is prevented from leaking directly into the suction space S1 So that the sealing function of the shaft seal 126 can be maintained.

Further, when the oil hole 126a is provided, the correlation in which the friction torque of the shaft seal 126 is increased due to the pressure increase in the discharge space S2 and the back pressure space 124 communicating therewith can be weakened. Therefore, there is an advantage that the constraint condition that the discharge pressure or the discharge area of the compressor can not be increased due to the inefficiency due to the increase of the friction torque of the shaft seal 126 can be mitigated.

Referring to FIG. 3, a plurality of oil holes 126a of the present embodiment may be formed. For example, a plurality of oil holes 126a may be arranged so as to pass through the shaft seal 126 in the axial direction of the rotary shaft 135 and be spaced along the circumferential direction of the rotary shaft 135. [ The oil holes 126a are formed to pass through the ring-shaped shaft seals 126 at predetermined intervals so that the oil can be uniformly supplied to the contact surfaces of the shaft seals 126 and the friction force is made non- Can be prevented.

The oil hole 126a may be formed in the axial direction of the rotary shaft 135 in order to minimize the deformation of the oil hole 126a during the assembly of the shaft seal 126. [ Hereinafter, the shaft seal 126 of the present embodiment will be described more specifically.

First, the shaft receiving portion 122 of this embodiment may have a seal receiving groove 122a. The seal receiving groove 122a may be recessed on the surface facing the back pressure space 124 and positioned adjacent to the outer circumferential surface of the rotating shaft 135. [ That is, the seal receiving groove 122a may be a space formed so as to be stepped on the inner peripheral surface of the bearing water portion 122 adjacent to the back pressure space 124. [ As shown, the shaft seal 126 of the present embodiment can be received in the seal receiving groove 122a. Of the surfaces forming the seal receiving groove 122a, grooves may be formed on the side surface facing the rotating shaft 135 to insert the stop ring 127 as described above.

The shaft seal 126 received in the seal receiving groove 122a may include first and second frictional portions 126b and 126c. As shown in the figure, the first friction portion 126b may be an inner circumferential surface of the shaft seal 126 which is configured to contact and rub against the outer circumferential surface of the rotary shaft 135. [ The second frictional portion 126c may be a surface adapted to contact and rub against the bottom surface of the seal receiving groove 122a. The oil hole 126a has one end communicating with the back pressure space 124 and the other end formed with the second friction portion 126c so as to abut the bottom surface of the seal receiving groove 122a.

As described above, when the end of the oil hole 126a is positioned on the bottom surface of the seal receiving groove 122a, the end of the oil hole 126a is positioned in parallel with the insertion direction of the shaft seal 126. [ Accordingly, even if the inner circumferential surface or the outer circumferential surface is deformed while the shaft seal 126 is pressed into the seal receiving groove 122a, the oil hole 126a has an advantage that the deformation of the diameter and the shape can be minimized. As a result, the design of the oil hole 126a is facilitated, and the effect that the plurality of oil holes 126a supply the oil to the friction surfaces can be reliably performed.

The structure and function of forming the oil hole 126a in the case where the shaft seal 126 is formed as a rectangular seal according to an embodiment of the present invention has been described above. Hereinafter, the structure and operation of forming the oil hole 126a in the case where the shaft seal 126 is made of a U-seal according to another embodiment of the present invention will be described.

FIG. 4 is a view showing a shaft seal 226 of an electric compressor 100 according to another embodiment of the present invention, and FIG. 5 is a perspective view showing a part of a shaft seal 226 shown in FIG. Referring to Figs. 4 and 5, the shaft seal 226 of the present embodiment further includes a back pressure groove 226d.

The shaft seal 226 of the present embodiment can be mounted in the seal receiving groove 122a formed in the bearing water portion 122 and the axial movement of the shaft seal 226 can be limited by the stop ring 127 have. However, the shaft seal 226 of this embodiment may have a back pressure groove 226d formed to be recessed in a plane facing the back pressure space 124. [ The shaft seal 226 of this embodiment has a first frictional portion 226b which is in contact with the outer circumferential surface of the rotary shaft 135 and a second frictional portion 226b which is in contact with the bottom surface and side surface of the seal receiving groove 122a, And a second friction portion 226c extending adjacent to the first friction portion 226c.

As a result, as shown, the shaft seal 226 can be made to have a U-shaped cross section in the radial direction. In the shaft seal 226 of the present embodiment, the high-pressure fluid in the back pressure space 124 can press the first and second frictional portions 226b and 226c away from each other while filling the back pressure grooves 226d.

At this time, the oil hole 226a passing through the shaft seal 226 may be configured such that one end communicates with the back pressure groove 226d and the other end is located at the second friction portion 226c. Since the second friction portion 226c and the first friction portion 226b are distributed adjacent to each other along the U-shaped outer surface, the oil passing through the oil hole 226a through the back pressure space 124 and the back pressure groove 226d The frictional torque can be reduced by spreading on the contact surfaces with the rotary shaft 135 and the bearing water portion 122, respectively.

The oil hole 226a can be made to abut the bottom surface of the seal receiving groove 122a so as to minimize the deformation of the oil hole 226a in the process of inserting the shaft seal 226 as in the previous embodiment. That is, the oil hole 226a penetrates the shaft seal 226 in the axial direction of the rotary shaft 135, one end communicates with the back pressure groove 226d, and the other end abuts against the bottom surface of the seal receiving groove 122a And may be formed in the second friction portion 226c.

Particularly, since the shaft seal 226 of this embodiment is inserted into the seal receiving groove 122a while being in contact with both the side surface of the seal receiving groove 122a and the outer peripheral surface of the rotating shaft 135, the oil hole 226a is inserted into the seal receiving groove 122a are effective to prevent deformation of the size or shape of the hole.

FIG. 6 is a view showing a shaft seal 326 of an electric compressor 100 according to another embodiment of the present invention, and FIG. 7 is a perspective view showing a part of a shaft seal 326 shown in FIG. Although the embodiment of the oil hole 226a considering the advantages of machining and assembling of the shaft seal 226 of the present invention has been described above, in another embodiment of the present invention, a structure capable of maximizing the reduction of the friction torque Will be described.

6 and 7, the oil hole 326a of the present embodiment may be configured to penetrate the shaft seal 326 in a direction intersecting the axial direction of the rotation shaft 135. [ The end of the oil hole 326a may be formed in the first friction portion 326b where the outer surface of the shaft seal 326 having the U-seal shape is in contact with and friction with the outer circumferential surface of the rotary shaft 135 have.

According to this structure, the oil that has passed through the oil hole 326a through the back pressure space 124 and the back pressure groove 326d is supplied between the outer peripheral surface of the rotary shaft 135 that is rotationally driven and the shaft seal 326, Can be performed. As in the previous embodiments, direct friction reduction can be achieved than when oil is supplied to the first friction portion 326b through the second friction portion 326c.

Further, unlike the example of the shaft seal 326 shown in FIGS. 6 and 7, the shaft seal 326 having a rectangular seal shape may be formed with an oil hole 326a penetrating through the first friction portion 326b.

The embodiments described above are applied to a shaft seal (not shown) that prevents leakage through the surface of the rotary shaft 135 between the back pressure space 124 and the suction space S1 in the closed scroll compressor having the back pressure space 124 126, 226, and 326 are formed with oil holes 126a, 226a, and 326a. However, the shaft seal including the oil hole of the present invention can be variously applied to a low-pressure electric compressor including a high-low-pressure separator plate through which a rotary shaft passes.

Specifically, the electric compressor according to the present invention may include a casing, a high-low-pressure separating plate configured to partition the internal space of the casing into a low-pressure space and a high-pressure space, and a rotating shaft configured to penetrate the high- The rotary shaft can be rotationally driven by the drive unit, and the fluid can be compressed by receiving the rotational force of the rotary shaft in the compression unit connected to the rotary shaft. That is, the fluid can be sucked into the compression unit in the low-pressure space, compressed, and then discharged into the high-pressure space.

In this case, the high-low-pressure separating plate of the electric compressor according to the present invention may include a bearing water portion formed to surround the rotary shaft, and a seal receiving groove recessed from the surface facing the high-pressure space and adjacent to the bearing water portion. The high-low-pressure separating plate may include a shaft seal which is inserted into the seal receiving groove and is in contact with the rotary shaft so as to seal the low-pressure space and the high-pressure space with each other, and has an oil hole communicating with the high-pressure space.

According to this, in an electric compressor having a structure in which a rotary shaft penetrates a high-pressure separating plate separating a low-pressure space and a high-pressure space, friction loss is increased by a shaft seal preventing leakage between the rotary shaft and the high- Lt; / RTI > Therefore, the efficiency of the compressor can be improved, and the case where the design of the discharge pressure or the discharge area of the compressor is restricted by the friction torque can be mitigated.

The present invention is not limited to the above-described embodiments, and various modifications and variations of the present invention are possible without departing from the scope of the present invention as set forth in the claims below. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the scope of the present invention.

100: electric compressor 101: casing
102: main frame 103: drive unit
104: compression unit 111: front cover
112: rear cover 113:
114: inlet 115: outlet
116: oil separator 117: back pressure line
121: Body part 122: Bearing part
122a: seal receiving groove 123: thrust plate
123a: thrust surface 124: back pressure space
125: Thrust seal
126, 226, 326: Shaft seal
126a, 226a, 326a: Oil hole
126b, 226b, 326b: a first frictional portion
126c, 226c, and 326c:
226d, 326d: back pressure groove 131:
132: rotor 135:
136: Balance weight 140: 1st scroll
141: fixed side end plate portion 142: fixed side wall portion
143: Fixed lap 150: Second scroll
151: turning side end plate portion 152: orbiting wrap
161: main bearing 162: sub bearing
163: eccentric bearing 171: pin
172: recess ring

Claims (8)

Casing;
A rotating shaft located inside the casing;
A main frame fixed to the casing and rotatably supporting the rotation shaft;
A drive unit configured to rotate the rotation shaft; And
And a compression unit having a first scroll positioned to be fixed to the casing and a second scroll connected to the rotation shaft and pivotally engaged with the first scroll,
The main frame includes:
A shaft receiving portion formed to surround the rotating shaft;
A back pressure space formed to receive fluid that presses said second scroll toward said first scroll; And
And a shaft seal inserted between the bearing water portion and the rotary shaft to seal the back pressure space, the oil seal having an oil hole communicating with the back pressure space. The method according to claim 1,
And one end of the oil hole is exposed toward the back pressure space, and the other end is positioned to abut the rotation shaft or the bearing water portion. 3. The method of claim 2,
Wherein the oil holes penetrate the shaft seal in the axial direction of the rotary shaft and are disposed so as to be spaced along the circumferential direction of the rotary shaft. The method according to claim 1,
Wherein the bearing portion has a seal receiving groove recessed in a surface facing the back pressure space and positioned adjacent to an outer circumferential surface of the rotary shaft to receive the shaft seal,
Wherein the shaft seal comprises:
A first friction portion contacting the outer peripheral surface of the rotating shaft; And
And a second friction portion formed to be in contact with a bottom surface of the seal receiving groove and formed with an end portion of the oil hole. The method according to claim 1,
Wherein the bearing portion has a seal receiving groove recessed in a surface facing the back pressure space and positioned adjacent to an outer circumferential surface of the rotary shaft to receive the shaft seal,
Wherein the shaft seal comprises:
A back pressure groove formed to be recessed on a surface facing the back pressure space;
A first friction portion contacting the outer peripheral surface of the rotating shaft; And
And a second friction portion which is in contact with the seal receiving groove and extends adjacent to the first friction portion, and in which an end portion of the oil hole is formed. 6. The method of claim 5,
One end of the oil hole communicates with the back pressure groove and the other end extends in the axial direction of the rotary shaft so as to abut the bottom surface of the seal receiving groove,
Wherein a plurality of oil holes are formed so as to be spaced along the circumferential direction of the rotary shaft. The method according to claim 1,
Wherein the shaft seal comprises:
A first friction portion contacting the outer peripheral surface of the rotating shaft; And
And a second friction portion that is brought into contact with the bearing portion,
Wherein one end of the oil hole is exposed toward the back pressure space and the other end is formed in the first friction portion. Casing;
A high-low-pressure separating plate configured to partition the internal space of the casing into a low-pressure space and a high-pressure space;
A rotating shaft configured to penetrate the high-low-pressure separator plate;
A drive unit for driving the rotation shaft;
And a compression unit configured to form a compression chamber in the casing and compress the fluid flowing from the low pressure space in response to the rotational force of the rotary shaft to discharge the fluid into the high pressure space,
The high-low-
A shaft receiving portion formed to surround the rotating shaft;
A seal receiving recess formed in a surface facing the high pressure space and adjacent to the bearing portion; And;
And a shaft seal which is inserted into the seal receiving groove to seal the low-pressure space and the high-pressure space with each other and which is in contact with the rotary shaft and communicates with the high-pressure space.

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