KR20090041731A - Linear compressor - Google Patents

Abstract

A linear compressor is provided to reduce the oil path for oil supply and return by directly connecting the oil supply path to the oil feed assembly mounted on the bottom of the frame and forming the oil return path in a linear shape on the top of the frame. A linear compressor comprises a cylinder(200) including a refrigerant compression space inside, a piston(300) which compresses the refrigerant while reciprocating inside the cylinder, a frame(520) having a mounting groove on the bottom, an oil feed assembly which is mounted on the mounting groove of the frame and pumps/supplies the oil, an oil supply path(520in) which is formed in a linear shape, is connected to the mounting groove of the frame and the lower part of the cylinder, and supplies the oil between the cylinder and the piston, and an oil return path(520out) which is formed in a linear shape, is connected to upper part of the frame and the upper part of the cylinder, and recovers the oil between the cylinder and the piston. The oil supply path and the oil return path are formed to be asymmetrical.

Description

Linear Compressor {LINEAR COMPRESSOR}

The present invention relates to a linear compressor, and more particularly, to a linear compressor capable of improving oil supply performance by improving an oil passage through which oil is circulated.

In general, the reciprocating compressor is configured to compress the refrigerant while the piston reciprocates linearly within the cylinder by forming a compression space in which the working gas is absorbed and discharged between the piston and the cylinder.

Recently, the reciprocating compressor includes a component such as a crank shaft in order to convert the rotational force of the drive motor to the reciprocating linear kinetic force of the piston, there is a problem that a large mechanical loss caused by the movement change occurs. Many linear compressors have been developed for this purpose.

Such a linear compressor, in particular, allows the piston to be directly connected to a linear motor in reciprocating linear motion, thereby eliminating mechanical loss due to motion switching, thereby improving compression efficiency, and having a simple structure, and controlling power input to the linear motor. Since the operation can be controlled, the noise is lower than that of other compressors, so it is widely applied to home appliances such as refrigerators used indoors.

1 is a view showing an example of a linear compressor according to the prior art.

Conventional linear compressors have a frame (1), a cylinder (2), a piston (3), a suction valve (4), a discharge valve assembly (5), a linear motor (6), and a motor cover (7) inside a shell (not shown). ), The supporter 8, the back cover 9, the main springs S1 and S2, the muffler assembly 10, and the oil supply device 20 are installed to be elastically supported.

The cylinder 2 is fitted to the frame 1 so that the discharge valve assembly 5 composed of the discharge valve 5a, the discharge cap 5b, and the discharge valve spring 5c blocks one end of the cylinder 2. On the other hand, the piston 3 is inserted inside the cylinder 2, and a thin suction valve 4 is installed to open and close the outlet 3a of the piston 2.

The linear motor 6 is installed so that the permanent magnet 6c can reciprocally linearly move while maintaining a gap between the inner stator 6a and the outer stator 6b, and the permanent magnet 6c is connected by the connecting member 6d. It is installed to be connected to the piston (3), and operates the piston (3) while the permanent magnet (6c) reciprocating linear movement by mutual electromagnetic force between the inner stator (6a), the outer stator (6b) and the permanent magnet (6c) .

The motor cover 7 supports the outer stator 6b in the axial direction to fix the outer stator 6b and is bolted to the frame 1, and the back cover 9 is coupled to the motor cover 7. The supporter 8 connected to the other end of the piston 3 is installed between the motor cover 7 and the back cover 9 so as to be elastically supported in the axial direction by the main springs S1 and S2, and sucks the refrigerant. Muffler assembly 10 is also fastened together with the supporter (8).

At this time, the main springs (S1, S2) includes four front springs (S1) and four rear springs (S2) in a position that is symmetrical up and down and left and right relative to the supporter (8), the linear motor (6) As it is actuated, the front springs S1 and the rear springs S2 behave in opposite directions while cushioning the piston 3 and the supporter 8. In addition, the refrigerant on the compression space P side acts as a kind of gas spring to cushion the piston 3 and the supporter 8.

The oil supply device 20 includes an oil supply pipe 21, an oil pumping unit 22, and an oil valve assembly 23, and is installed to communicate with an oil circulation path (not shown) formed in the frame 1.

Therefore, when the linear motor 6 is operated, the piston 3 and the muffler assembly 10 connected thereto are reciprocated linearly, and the suction valve 4 and the discharge valve assembly are changed as the pressure of the compression space P is varied. The operation of (5) is automatically adjusted, and by this operation, the refrigerant is compressed past the intake pipe on the shell side, the opening of the back cover 9, the muffler assembly 10, and the inlets 3a of the piston 3. It is sucked into the space P and compressed, and then exits through the discharge cap 5b, the roof pipe and the outlet pipe on the shell side.

2 is a view showing an example of the oil circulation path of the linear compressor according to the prior art. In the conventional linear compressor, the oil circulating flow path is divided into an oil supply flow passage 1in formed at the lower inner side of the frame 1 and an oil return flow passage 1out formed at the upper inner side of the frame 1, and the oil supply flow passage 1in. The oil recovery flow path 1out is formed to have the same position and angle at the upper and lower portions of the frame 1 with the same size for convenience of manufacture. That is, the diameter of the oil supply flow path 1in and the diameter of the oil return flow path 1out are formed the same, and the angle A and the oil return flow path 1out which form the oil supply flow path 1in and the center axis of the cylinder 2 are 1out. ) And the angle B between the central axis of the cylinder 2 are equally formed. At this time, the oil supply passage (1in) is inclined so as to communicate with the portion in which the oil valve assembly 23 (shown in Figure 1) is mounted on the lower surface of the frame 1 and communicate with the lower cylinder (2), oil recovery The flow passage 1out is inclined so as to communicate with the upper portion of the cylinder 2 and to be exposed to the upper surface of the upper portion of the frame 1.

Therefore, when the vibration generated as the piston 3 reciprocates linearly and is transmitted to the oil pumping unit 22, a pressure difference is generated by the oil pumping unit 22, and the oil supply pipe 21 is caused by such a pressure difference. The oil at the bottom of the shell is pumped through the shell, as shown in FIG. After lubrication / cooling while being supplied between the cylinder 2 and the piston 3 along the), it flows along one surface of the frame 1 through the oil return flow passage 1out and is collected under the shell.

However, the linear compressor according to the prior art is easy to manufacture because the oil circulation flow path is formed to have the same angle at the same size in the upper and lower parts of the frame, but the oil supply performance is limited as design freedom falls, and operation reliability is due to the oil supply imbalance. There is a problem of dropping.

In addition, in the linear compressor according to the prior art, the oil supply pipe and the oil pumping part are respectively mounted on one side of the frame, and the oil valve assembly is mounted on the other side of the frame so as to communicate with the oil supply pipe and the oil pumping part. Oil is supplied along the lower part of the valve assembly, the oil pumping part, the upper part of the oil valve assembly, the oil supply flow path, the flow path communicating with the oil supply pipe inside the frame, the flow path communicating with the oil pumping part, and the flow path as the oil supply flow path is formed separately. In addition to the long, there is a problem that the oil supply performance is reduced due to the flow resistance.

The present invention has been made to solve the above problems of the prior art, to improve the oil circulation flow path for circulating oil to improve the oil supply performance as well as to provide a linear compressor that can shorten the oil supply flow path length. There is this.

The present invention for solving the above problems is a cylinder provided with a compression space in which the refrigerant is compressed; A piston for compressing the refrigerant while reciprocating linear motion inside the cylinder; One end of the cylinder is fixed, the frame provided with a mounting groove at the bottom; An oil supply assembly mounted in a mounting groove of the frame and pumping / supplying oil; An oil supply flow path provided in a linear shape in the lower part of the frame to communicate with the mounting groove of the frame and the lower part of the cylinder, and supplying oil between the cylinder and the piston; And, the linear compressor, characterized in that it is provided in a linear shape inside the upper portion of the frame so as to communicate with the upper surface and the upper cylinder of the frame asymmetrically with the oil supply flow path, the oil recovery flow path for recovering oil between the cylinder and the piston: To provide.

Further, in the present invention, the angle that the oil supply flow path makes with the central axis of the cylinder is characterized in that the oil recovery flow path is formed larger than the angle made with the central axis of the cylinder.

Further, in the present invention, the oil supply passage is characterized in that the diameter is formed larger than the oil recovery passage.

Further, in the present invention, the oil recovery passage is characterized in that it is formed shorter than the oil supply passage.

On the other hand, the present invention is a cylinder having a compression space therein compressed refrigerant; A piston for compressing the refrigerant while reciprocating linear motion inside the cylinder; One end of the cylinder is fixed, the frame provided with a mounting groove at the bottom; An oil supply assembly mounted in a mounting groove of the frame and pumping / supplying oil; And, it is provided in a linear shape inside the lower portion of the frame so as to communicate with the mounting groove of the frame, an oil supply passage for supplying oil between the cylinder and the piston; provides a linear compressor comprising a.

The linear compressor according to the present invention configured as described above is formed in a straight line shape so that the oil supply passage is in direct communication with the oil supply assembly mounted on the lower portion of the frame, and the oil return passage is linearly asymmetric with the oil supply passage in the upper portion of the frame. Since it is formed, it is possible to shorten the flow path of the oil supply flow path and the oil recovery flow path and design freely, thereby improving the oil supply performance, and further, there is an advantage of improving the operation reliability through smooth oil supply.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a view showing an example of a linear compressor according to the present invention.

An example of the linear compressor 100 according to the present invention includes a cylinder 200, a piston 300, an inner stator 420 and an outer stator 440, and a permanent magnet 460 in a shell 110 that is a closed container. Including linear motor 400, oil supply assembly 900, if the permanent magnet 460 is linearly reciprocated by the mutual electromagnetic force between the inner stator 420 and the outer stator 440, connected to the permanent magnet 460 The piston 300 is linearly reciprocated together with the permanent magnet 460, and the oil stored in the bottom surface of the shell 110 is pumped / supplied by the vibration of the piston 300 to the cylinder 200. ) And the piston 300 is lubricated.

The inner stator 420 is fixed to the outer circumference of the cylinder 200, the outer stator 440 is fixed by the frame 520 and the motor cover 540 in the axial direction, the frame 520 and the motor cover 540 Is coupled to each other by a fastening member such as a bolt, and the outer stator 440 is fixed between the frame 520 and the motor cover 540. The frame 520 may be integrally formed with the cylinder 200 or may be manufactured separately from the cylinder 200 and combined with the cylinder 200. 3 illustrates an example in which the frame 520 and the cylinder 200 are integrally formed.

The supporter 320 is connected to the rear of the piston 300. Four front main springs 820 are supported at both ends by the supporter 320 and the motor cover 540. In addition, the four rear main springs 840 are supported at both ends by the supporter 320 and the back cover 560, and the back cover 560 is coupled to the rear of the motor cover 540. A suction muffler 700 is also provided at the rear of the piston 300, and refrigerant flows into the piston 300 through the suction muffler 700, thereby reducing noise during refrigerant suction.

The inside of the piston 300 is hollow to allow the refrigerant introduced through the suction muffler 700 to enter and compress the compression space P formed between the cylinder 200 and the piston 300. A suction valve 610 is installed at the front end of the piston 300, and the suction valve 610 is opened so that the refrigerant flows into the compression space P from the piston 300, and again the piston () in the compression space P. The tip of the piston 300 is closed so as not to flow into the 300.

When the refrigerant is compressed to a predetermined pressure or more by the piston 300 in the compression space P, the discharge valve 620 located at the tip of the cylinder 200 is opened. The discharge valve 620 is installed to be elastically supported by the spiral discharge valve spring 630 inside the support cap 640 fixed to one end of the cylinder 200. The compressed high-pressure refrigerant is discharged into the discharge cap 660 through a hole formed in the support cap 640, and then discharged to the outside of the linear compressor 100 through the loop pipe L to circulate a refrigeration cycle.

The oil supply assembly 900 is manufactured in the form of a kit, and is installed to be axially supported between the mounting groove 521 of the frame 520 and the motor cover 540. Of course, a predetermined elastic member (not shown) such as a leaf spring may be inserted to increase the fastening force when the refueling assembly 900 is mounted. In addition, when the oil supply assembly 900 is mounted, it is installed to communicate with an oil circulation passage (not shown) provided in the frame 520 to supply oil between the cylinder 200 and the piston 300. Therefore, when vibration occurs while the piston 300 reciprocates linearly, the oil supply assembly 900 is operated by the vibration transmitted to the oil supply assembly 900 while pumping / circulating oil stored in the bottom surface of the shell 110.

4 is a view illustrating an example of an oil circulating oil path of the linear compressor according to the present invention. In the linear compressor of the present invention, the oil circulating flow path has a mounting groove 521 formed so that the oil supply assembly 900 (shown in FIG. 3) can be mounted on the lower portion of the frame 520, and the frame is in communication with the mounting groove 521. An oil supply flow path 520in formed in a linear shape at a lower inner side of the 520 and an oil recovery flow path 520out formed in a linear shape at an upper inner side of the frame 520, and include an oil supply flow path 520in and an oil recovery flow path. 520out is formed to have different positions and different angles at the top and bottom of the frame 520 to improve the oil supply performance.

At this time, the oil supply flow path 520in is formed in a straight shape inclined upwardly in the lower side of the frame 520 from the mounting groove 521 to the lower gap between the cylinder 200 and the piston 300, and the oil recovery flow path ( 520out) is also formed in a straight line inclined downward in the upper part of the frame 520 from the upper surface of the frame 520 to the upper gap between the cylinder 200 and the piston 300, resulting in a flow path length of oil It can shorten and improve lubrication performance.

In addition, the diameter d1 of the oil supply flow path 520in is formed to be larger than the diameter d2 of the oil recovery flow path 520out, but the oil supply flow path 520in initially opens the flow path to reduce the flow path resistance of the oil. On the other hand, the oil recovery flow path 520out may be narrowly formed so that the oil recovery flow path 520out can quickly exit the oil flow path even if the pumping force of the oil is reduced due to the flow resistance.

In addition, the oil recovery path 520 in and the angle A formed with the central axis of the cylinder 200 are greater than the oil recovery flow path 520 out and the angle B formed with the central axis of the cylinder 200 to recover the oil. Although the length of the flow path 520out is shorter than the length of the oil supply flow path 520in, the oil supply flow path 520in may be formed to have a long flow path due to a large pumping force. 520out) preferably shortens the flow path so that the oil can escape quickly even if the oil pumping force is reduced due to the flow path resistance.

Of course, the oil supply flow path 520in and the oil recovery flow path 520out may improve oil supply performance by implementing various positions, angles, sizes, etc. in the frame 520, but supply oil to the frame 520 at the beginning of production. Only setting values of equipment required to form the flow path 520in and the oil recovery flow path 520out can be easily inputted.

In addition, the oil supply flow path 520in is preferably configured to communicate with the mounting groove 521 of the frame 520 on which the oil supply assembly 900 is mounted, so that the oil supply flow path is shorter, but the mounting groove 521 may be a frame. One side of the lower surface of the 520 is formed to be open, the oil supply assembly 900 is mounted to be axially fitted into the mounting groove 521 from one surface of the frame 520.

More specifically, an example of the oil supply assembly 900 includes a friction member 902, a piston 903, a pair of oil springs 904, an oil intake valve 905, and an oil discharge valve 906 inside the case 901. ) Is manufactured in the form of installed kit.

The case 901 may be provided at both sides of the inlet / outlet 901a and 901b through which the refrigerant flows in and out of the hollow shaft shape, while the inlet 901a is provided at the bottom in the form of a pipe, while the outlet 901b is provided. The other end is provided at the upper end, the flow path of the inlet (901a), the flow path of the inner space, the flow path of the outlet (901b) is formed so as to be connected to the 90 ° bent. Of course, when the case 901 is mounted in the mounting groove 521 of the frame 520, the outlet 901b of the case 901 is installed to communicate with the oil supply passage 520in of the frame 520. The case 901 may be manufactured in various forms and may be made of plastic to reduce production costs. The case 901 may include a friction member 902, an oil piston 903, oil springs 904, and an oil suction valve 905. ) And an oil discharge valve 906 may be configured as at least two members so as to be embedded therein so as to be configured in the form of a kit. For example, the pipe portion having the inlet 901a may be manufactured separately from the case body, and the above components may be embedded in the case body, and then the pipe portion having the inlet may be assembled into the case body.

The friction member 902 is a kind of bush mounted along the inner circumferential surface of the case 901. As the case 901 is made of plastic, the friction member 902 may be reciprocated linearly even if the metal oil piston 903 reciprocates linearly. It is installed to reduce friction / wear. Of course, the friction member 902 may be installed only in a partial section of the case 901 corresponding to the stroke length in which the oil piston 903 is a length in which the oil piston 903 reciprocates linearly in a hollow shaft shape. The oil piston 903 reciprocates linearly inside the friction member 902, and has a hole 903h axially penetrated in the center to allow oil to pass therethrough.

The oil springs 904 elastically support both ends of the oil piston 903 axially inside the case 901. One oil spring 904 is installed to be supported at one end of the oil piston 903 and the stepped portion of the inlet 901a and the inner space of the case 901, and the other oil spring 904 is the oil piston ( The other end of 903, the inner space of the case 901 and the stepped portion of the outlet 901b are provided to be supported.

The oil intake valve 905 is installed at the stepped portion of the inlet and the inner space of the case 901, and the oil discharge valve 906 is a hole of the oil piston 903 through which the refrigerant passes through the oil piston 903. (903h) It is installed at one end. The oil intake / discharge valves 905 and 906 are manufactured in a thin plate like the intake valve 310 (shown in FIG. 3), and are configured to be opened and closed according to the pressure of the refrigerant as the inner portion is formed in a spiral form. Of course, the oil intake / discharge valves 905 and 906 adjust the oil supply while the center portion is opened and closed as the outer circumferential portion is supported by the oil springs 904.

In addition, the oil supply assembly 900 is provided with an anti-rotation protrusion 907 so as not to rotate even when mounted in the mounting groove 521 of the frame 520, and correspondingly to the mounting groove 521 of the frame 520. Also, a rotation preventing groove (not shown) may be provided.

Therefore, when looking at the oil circulation process in the linear compressor configured as described above, when the vibration generated as the piston 300 reciprocates linearly transmitted to the oil supply assembly 900 (shown in FIG. 3), the oil supply assembly 900 (FIG. 3) The oil at the bottom of the shell 110 (shown in FIG. 3) is pumped through the oil supply assembly 900 (shown in FIG. 3) by the pressure difference generated therein, and the thus pumped oil is supplied to the oil supply flow path ( Lubricated / cooled while being supplied between the cylinder 200 and the piston 300 along 520in, and then flows down one side of the frame 520 through the oil return flow passage 520out to shell 110 (shown in FIG. 3). Will be collected to the bottom.

At this time, the oil supply flow path (520in) is formed in a relatively wide flow path to reduce the flow resistance of the oil, the oil recovery flow path (520out) is formed in a relatively narrow and at the same time short the flow path resistance even if the pumping force is reduced by the flow path resistance Since oil can be discharged, oil supply performance can be improved, and friction / wear between the cylinder 200 and the piston 300 can be reduced, thereby increasing operating reliability.

In addition, since the oil pumped in the oil supply assembly 900 is supplied through the straight oil supply flow path 520 in of the frame 520, the oil supply assembly 900 may be disposed between the cylinder 200 and the piston 300. The oil supply passage can be shortened to a gap, so that the oil supply performance can be further improved.

In the above, the present invention has been described in detail by way of examples based on the embodiments of the present invention and the accompanying drawings. However, the scope of the present invention is not limited by the above embodiments and drawings, and the scope of the present invention will be limited only by the contents described in the claims below.

1 is a view showing an example of a linear compressor according to the prior art.

Figure 2 is a view showing an example of the oil circulation path of the linear compressor according to the prior art.

3 shows an example of a linear compressor according to the invention.

4 is a view showing an example of the oil circulation path of the linear compressor according to the present invention.

<Explanation of symbols on main parts of the drawings>

200: cylinder 300: piston

520: frame 520in: oil supply flow path

520out: oil return flow path 521: mounting groove

900: Refueling Assembly

Claims (5)

A cylinder having a compression space inside the refrigerant compressed therein; A piston for compressing the refrigerant while reciprocating linear motion inside the cylinder; One end of the cylinder is fixed, the frame provided with a mounting groove at the bottom; An oil supply assembly mounted in a mounting groove of the frame and pumping / supplying oil; An oil supply flow path provided in a linear shape in the lower part of the frame to communicate with the mounting groove of the frame and the lower part of the cylinder, and supplying oil between the cylinder and the piston; And, And a oil return flow path provided in a straight shape inside the upper part of the frame so as to communicate with an upper surface of the frame and an upper portion of the frame asymmetrically with the oil supply flow path, and recovering oil between the cylinder and the piston. The method of claim 1, And the angle at which the oil supply passage is formed with the central axis of the cylinder is larger than the angle at which the oil return passage is formed with the central axis of the cylinder. The method of claim 2, And the oil supply flow passage has a larger diameter than the oil return flow passage. The method of claim 2, And the oil return flow path is formed shorter than the oil supply flow path. A cylinder having a compression space inside the refrigerant compressed therein; A piston for compressing the refrigerant while reciprocating linear motion inside the cylinder; One end of the cylinder is fixed, the frame provided with a mounting groove at the bottom; An oil supply assembly mounted in a mounting groove of the frame and pumping / supplying oil; And, And an oil supply passage provided in a linear shape in the lower part of the frame so as to communicate with the mounting groove of the frame and supplying oil between the cylinder and the piston.

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