WO2020158369A1

WO2020158369A1 - Linear compressor

Info

Publication number: WO2020158369A1
Application number: PCT/JP2020/000841
Authority: WO
Inventors: 小山　昌喜; 智弘小松; 中津川　潤之介; 鈴木　達也; 瑛人大畠
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2019-01-31
Filing date: 2020-01-14
Publication date: 2020-08-06
Also published as: JP7199239B2; JP2020122456A

Abstract

The present invention provides a technology suitable for reducing the size and noise of an air compressor. This linear compressor is provided with a compression part 11 which compresses air in a compression chamber 12B by means of the reciprocating motion of a piston 13, and a linear motor 5 which drives the piston 13. The linear motor 5 is provided with a movable element 8 which is connected to the piston 13 and reciprocates, a spring 10 which vibrates together with the movable element 8, and a fixed element 7 which causes a magnetic force to act between the fixed element 7 and the movable element 8. A casing 6 constitutes a spring accommodating space for accommodating the spring 10 between the fixed element 7, which is accommodated on one end side of the casing 6, and an air inlet 24 provided in the other end of the casing 6. An intermediate drawing suction passageway 26 is formed between an intake valve 14 provided at the entrance of the compression chamber 12B and the spring accommodating space V2. The spring accommodating space V2 has a spatial cross-sectional area greater than the passageway cross-sectional area of the intermediate suction passageway 26 and the passageway cross-sectional area constituted by the inlet 24.

Description

Linear compressor

The present invention relates to a linear compressor that reciprocally drives a piston using a linear motor.

Equipment built-in air compressors are used in equipment that uses compressed air as a power source or equipment that uses high-pressure air, and are required to be small, lightweight, and low in noise. It

For example, in the abstract of International Publication No. WO 2014/051016 (Patent Document 1), "a cylindrical casing of a compressor is described as a compressor that solves conflicting technical problems of mounting a silencer and downsizing the device". And a second lid portion that forms a small chamber together with the first lid portion, the cylindrical portion, and the first lid portion that form a part of Is provided with a suction nozzle for sucking air into the small chamber in the lid part of the compressor. In addition, in page 5 and FIG. 2 of Patent Document 1, a cylindrical casing is composed of a crankcase for accommodating a crank portion, and the rotational movement of a motor arranged outside the crankcase is reciprocated by a piston through the crank. The configuration for converting to is described. Further, on page 6 of Patent Document 1, it is described that the expansion-type silencing function is realized by the intake port, the small chamber, and the intake nozzle described above.

International publication 2014/051016 pamphlet

Demand for smaller, lighter, and quieter air compressors with built-in equipment is becoming stronger, and high reliability that enables long-term continuous operation is required. Above all, the temperature rise due to heat generation of the motor becomes a problem due to continuous operation for a long time. For this reason, it is indispensable to mount a cooling fan on the motor, but this is a conflicting technical issue in reducing the size of the compressor. In Patent Document 1, there is no consideration for cooling the motor arranged outside the crankcase. Further, in the compressor of Patent Document 1, it is necessary to newly form a small chamber outside the crankcase in order to realize the expansion type muffling function, and it is necessary to increase the volume of the small chamber to improve the expansion type muffling function. Yes, the compressor becomes larger.

The present invention provides a technology suitable for downsizing and noise reduction of an air compressor.

The linear compressor of the present invention is
A compression unit that compresses the air in the compression chamber by the reciprocating motion of the piston, and a linear motor that drives the piston,
The linear motor is a stator that drives the mover by applying a magnetic force between the mover that is connected to the piston and reciprocates, a vibration spring that can vibrate with the mover, and the mover. When,
In a linear compressor equipped with
A housing for accommodating the stator of the linear motor is provided on one end side, an air inlet is provided at the other end, and a spring accommodating space for accommodating the vibration spring is formed between the stator and the inlet. Equipped with a casing,
An intermediate suction passage is provided between the suction valve provided at the inlet of the compression chamber and the spring accommodating space,
In the spring accommodating space, a space sectional area perpendicular to the reciprocating direction of the mover is larger than a passage sectional area of the intermediate suction passage and a passage sectional area of the suction port.

According to the present invention, it is possible to reduce the size and height of the compressor by integrating the motor case (casing) and the silencer, and reduce the heat generation of the compressor by cooling the linear motor with the intake air. You can As a result, the present invention can provide a compact, highly quiet, and highly reliable air compressor (linear compressor).

FIG. 3 is a cross-sectional view (vertical arrangement) parallel to the X axis, showing the configuration of the linear compressor according to the first embodiment. Sectional drawing parallel to the X-axis of a linear compressor different from FIG. 1A (vertical arrangement). IC-IC cross section of Figure 1B (vertical layout). It is a sectional view parallel to an X-axis showing composition of a linear compressor in horizontal type arrangement. It is a sectional view parallel to the X-axis of a (horizontal type arrangement) linear compressor different from FIG. 1D. FIG. 3 is a sectional view conceptually showing the structure of a linear motor of the linear compressor of the first embodiment. Sectional drawing which shows the III-III cross section of the linear compressor of FIG. 1A. Sectional drawing which shows the IV-IV cross section of the linear compressor of FIG. 1A. FIG. 3 is a diagram showing the muffling characteristics of the linear compressor of the first embodiment. FIG. 4 is a diagram showing an example of noise measurement results of the linear compressor of the first embodiment. FIG. 3 is a diagram showing a temperature change of the linear compressor of the first embodiment. FIG. 6 is a transverse cross-sectional view showing the configuration of the linear compressor according to the second embodiment. Sectional drawing parallel to an X-axis which shows the structure of the linear compressor of Example 3. FIG. Sectional drawing parallel to the X-axis of a linear compressor different from FIG. 9A. 9B is a sectional view taken along line IX-IX in FIG. 9B. The block diagram of the Example of the refrigerator using the linear compressor which concerns on this invention. The block diagram of the Example of the air suspension for vehicles using the linear compressor which concerns on this invention.

Hereinafter, embodiments of the linear compressor of the present invention and devices equipped with the linear compressor will be described with reference to the drawings.

The compressor according to the present invention is a reciprocating compressor (hereinafter referred to as a linear compressor) using a direct-acting motor (linear motor) among reciprocating compressors (reciprocating compressor). It is a compressor suitable for use as an air compressor (hereinafter referred to as an air compressor).

In this embodiment, the X axis, the Y axis and the Z axis are defined as shown in each figure. The X axis is defined in the direction along the longitudinal direction of the mover 8 and along the moving direction of the mover 8. The Y axis is defined in a direction perpendicular to the flat plate surface of the movable element 8 having a flat plate shape, and is orthogonal to the X axis. The Z axis is defined in the direction perpendicular to the X axis and the Y axis. Therefore, the X axis, the Y axis, and the Z axis are orthogonal to each other. The Y-axis direction is the thickness direction of the mover 8, and the Z-axis direction is the width direction of the mover 8. Further, based on the moving direction of the mover 8 (X-axis direction), the side of the compression unit 11 with respect to the stator of the linear motor 5 (armature 7 in the following embodiments) is called the front side, and the opposite side (spring 10). May be described as the back side.

[Example 1]
FIG. 1A is a cross-sectional view parallel to the X axis, showing the configuration of the linear compressor of the first embodiment (vertical arrangement). FIG. 1B is a sectional view parallel to the X axis of the linear compressor, which is different from FIG. 1A (vertical arrangement). FIG. 1C is a cross-sectional view of the IC-IC in FIG. 1B (vertical arrangement). FIG. 1D is a cross-sectional view parallel to the X axis, showing the configuration of the linear compressor in the horizontal arrangement. FIG. 1E is a sectional view parallel to the X-axis of the (horizontal arrangement) linear compressor, which is different from FIG. 1D. FIG. 2 is a sectional view conceptually showing the structure of the linear motor of the linear compressor of the first embodiment. FIG. 3 is a sectional view showing a III-III section of the linear compressor of FIG. 1A. FIG. 4 is a sectional view showing a IV-IV section of the linear compressor of FIG. 1A.

The linear compressor includes a linear motor 5 and a compression unit 11 having a cylinder 12 and a piston 13. The linear motor 5 causes an electric current to flow through the coil 7B of the armature 7 to reciprocate the mover 8 in the axial direction and drive the piston 13 of the compression unit 11 in the same direction as the mover 8 to reciprocate. It is a thing. For this reason, the compression unit 11 is arranged on one end side (front side) of the linear motor 5. The compression unit 11 is configured by a device that compresses the air in the compression chamber 12B by the reciprocating motion of the piston 13.

The linear motor 5 is provided as a drive source for the compression unit 11 in the linear compressor. The linear motor 5 is configured to include a casing 6 that forms a cylindrical outer shell, an armature 7 that is disposed inside the casing 6, a mover 8, and a spring 10 (10A, 10B). That is, the linear motor 5 drives the mover 8 by applying a magnetic force between the mover 8 that is connected to the piston 13 and reciprocates, the spring 10 that can vibrate together with the mover 8, and the mover 8. And a stator (the armature 7 in this embodiment).

The casing 6 of the linear motor 5 is composed of a motor case 6A, a linear base 6B, and a case end plate 6C. The casing 6 accommodates the stator (armature 7) of the linear motor 5 on one end side, and has an air suction port 24 at the other end, and between the stator (armature 7) and the suction port 24. A spring housing space V2 for housing the spring 10 is formed.

In addition to the armature 7, a mover 8 and a spring 10 are housed inside the motor case 6A. A linear base 6B is provided on one end side of the motor case 6A (on the side where the compression section 11 is provided, on the front end side). On the other end side (rear end side) of the motor case 6A, a case end plate 6C is provided so as to close the opening.

A pair of armatures 7 and a plate-shaped mover 8 are provided in the motor case 6A of the linear motor 5. The pair of armatures 7 are provided so as to sandwich the mover 8 and form a stator fixed in the motor case 6A. Each armature 7 is formed of, for example, laminated electromagnetic steel sheets, and has a plurality of cores 7A spaced apart in the X-axis direction in FIG. 2, a plurality of coils 7B wound around each core 7A, and these. Of cores 7A and coils 7B in a pre-assembled state, and a bridge 7D that forms a magnetic circuit between adjacent cores 7A.

On the other hand, the mover 8 is formed as a rectangular flat plate member (flat plate member) extending in the axial direction (X-axis direction) of the motor case 6A while being sandwiched between the pair of armatures 7. That is, the mover 8 extends in the axial direction (X-axis direction) in the motor case 6A along the central axis of the linear motor 5, and the pair of armatures 7 are arranged on both sides thereof. The mover 8 includes a yoke 8A formed of a magnetic material in a flat plate shape, and a plurality of permanent magnets 8B arranged in a flat plate shape on the front surface and the back surface of the yoke 8A. In the present embodiment, the permanent magnet 8B has flat surfaces on both end surfaces in the Y-axis direction, one flat surface (one end surface) on the front surface side of the yoke 8A, and the other flat surface (the other end surface) on the yoke 8A. Is located on the back side of. The permanent magnet 8B is formed as a quadrangular plate body as shown in FIG. 2, and a total of three permanent magnets 8B are arranged at intervals in the length direction (X-axis direction) of the mover 8.

In the present embodiment, the compressor main body including the linear motor 5 and the compression unit 11 is arranged with the Y axis in the horizontal direction. That is, the mover 8 is formed in a flat plate shape, and is arranged such that the reciprocating direction (X axis direction) and the flat plate thickness direction (Y axis direction) are horizontal. In this case, the plate-shaped mover 8 is arranged such that its plate surface (that is, the Z axis) is oriented along the vertical direction (longitudinal direction), and such an arrangement will be referred to as a vertical arrangement. 1A and 1B show a state in which the compressor body is vertically arranged.

The mover 8 may be arranged so that the plate thickness direction (Y-axis direction) is the vertical direction, as shown in FIGS. 1D and 1E. In this case, the plate-shaped mover 8 is arranged with its plate surface (that is, the Z-axis) oriented in the horizontal direction (sideways), and such an arrangement will be referred to as a horizontal arrangement.

Each core 7A of the armature 7 has a magnetic pole at its end face facing the mover 8 and is excited by energizing each coil 7B. The core 7A of the armature 7 and the permanent magnets 8B of the mover 8 generate a magnetic attractive force and a repulsive force between the coils 7B by energizing the coils 7B, whereby the mover 8 is The pair of armatures 7 arranged in the Y-axis direction are driven so as to repeat the reciprocating motion in the longitudinal direction (X-axis direction) in the motor case 6A.

A plurality of pairs of support members 9 functioning as bearings are provided between the armature 7 and the mover 8. The support member 9 of each set supports the mover 8 movably in the length direction (X-axis direction) thereof. In this embodiment, the support member 9 is composed of rollers, but it may be composed of a member that slidably supports the mover 8.

The spring 10 is located inside the motor case 6A, located on the other end side (rear side) of the linear motor 5. The spring 10 has a spring 10A whose one end is supported on the other end (rear end) side of the armature 7 and one end which is supported on a connector 8C provided on the other end (rear end) side of the mover 8. 10B and two sets of springs. The other end of the spring 10A is supported by the connector 8C, and the other end of the spring 10B is supported by the motor case end plate 6C. The spring 10A and the spring 10B expand and contract in the X-axis direction, and the other end side of the spring 10A and the one end side of the spring 10B are configured to be movable in the X-axis direction together with the connector 8C. The mover 8 is basically composed of the yoke 8A and the permanent magnet 8B, but the connector 8C may be regarded as an element of the mover 8.

The spring 10 is composed of a compression coil spring and is always installed in a compressed state. As the mover 8 reciprocates in the X-axis direction, the spring 10 is elastically deformed so that the

springs

10A and 10B alternately expand and contract in the X-axis direction (axial direction of the spring). .. The spring 10 (10A, 10B) constitutes a resonant spring capable of vibrating together with the mover. Therefore, the spring 10 (10A, 10B) may be called a vibration spring.

As described above, the linear motor 5 of the present embodiment is arranged so that the casing 6, the armature 7 fixedly arranged in the casing 6, and the casing 6 are movable so as to face the armature 7. A mover 8 formed in a flat plate shape, a plurality of permanent magnets 8B arranged in the mover 8 at a distance from each other in the longitudinal direction of the mover 8, and the mover 8 relatively moves in the longitudinal direction with respect to the armature 7. A plurality of magnetic poles arranged on the armature 7 and a plurality of support members 9 provided between the armature 7 and the mover 8 for supporting the mover 8 movably in the longitudinal direction thereof. It is configured to include.

The compression unit 11 of the linear compressor 4 includes a cylinder 12, a piston 13, a suction valve 14, a cylinder head 17, a discharge valve 16 and the like. Note that, in FIG. 1, the intake valve 14 is in a position that cannot be seen, so that position is indicated by reference numeral 14. The suction valve 14 is provided at the position of the suction hole 15A as shown by the broken line in FIG. The compression unit 11 is driven so that the piston 13 reciprocates forward and backward in the X-axis direction by the reciprocating movement of the mover 8 of the linear motor 5, and thereby the air (outside air) in the compression chamber 12B. It is compressed to generate compressed air (that is, working gas).

The cylinder 12 is closed at one end side (front side in the X-axis direction) by the head plate 15 to which the suction valve 14 is attached and fixed at the other end side (rear side in the X-axis direction) to the linear base 6B. Installed. The cylinder 12 is formed in a cylindrical shape using, for example, an aluminum material.

The piston 13 is fitted in the cylinder 12 so as to be slidable in the X-axis direction. The piston 13 constitutes a movable partition wall that divides the inside of the cylinder 12 into a non-compression chamber 12A and a compression chamber 12B. The piston 13 is connected to the mover 8 of the linear motor 5 by a connecting tool 13A. Accordingly, the piston 13 is provided so as to be slidably displaced with respect to the cylinder 12 in the axial direction of the linear motor 5 (motor case 6A), that is, in the X-axis direction, and the cylinder 12 is interlocked with the reciprocating motion of the mover 8. Reciprocates inside. In other words, the piston 13 is arranged on the axis line in the moving direction (X axis) of the mover 8 of the linear motor 5.

The head plate 15 is provided on one end side of the cylinder 12 so as to close one end of the cylinder 12. As shown in FIGS. 3 and 4, the head plate 15 has a suction hole 15A that is in constant communication with the compression chamber 12B of the cylinder 12, a suction valve 14 that covers the suction hole 15A so that the suction hole 15A can be opened and closed, and a compression chamber 12B of the cylinder 12. A discharge hole 15B that is in constant communication with the discharge hole 15B and a discharge valve 16 that covers the discharge hole 15B so as to be opened and closed are provided. The suction valve 14 opens the suction hole 15A in the suction stroke of the compression unit 11 to communicate the compression chamber 12B with the suction space 18, and closes the suction hole 15A in the compression stroke to close the inside of the compression chamber 12B to the suction space 18. Cut off. On the contrary, the discharge valve 16 closes the discharge hole 15B in the suction stroke of the compression section 11 to shut off the compression chamber 12B from the discharge space 19 side, and opens the discharge hole 15B in the compression stroke to open the inside of the compression chamber 12B. It communicates with the discharge space 19.

The cylinder head 17 is arranged together with the head plate 15 on one end side of the cylinder 12 (an end side opposite to the side where the linear motor is provided) so as to close one end of the cylinder 12. The cylinder head 17 has a suction space 18 and a discharge space 19, and the suction chamber 18 and the discharge space 19 are fitted to the head plate 15 on the compression chamber 12B side. As a result, the suction space 18 communicates with the suction hole 15A, and the discharge space 19 communicates with the discharge hole 15B with the discharge valve 16 opened. Further, the cylinder head 17 has a head suction port 17A communicating with the suction space 18 and a discharge port 17B communicating with the discharge space 19.

On the other hand, a motor case end plate 6C provided on the other end side of the motor case 6A is provided with an air suction port 24. The suction port 24 sucks air from the outside into the internal space of the motor case 6A in the suction stroke of the compression unit 11. The suction port 24 is connected to the suction silencer 25 on the outer side of the motor case 6A. The suction silencer 25 is a sound absorbing silencer, and is connected to the suction side of the compression unit 11 via the suction port 24. The suction silencer 25 is always in communication with the atmosphere and reduces noise leaking from the suction port 24 to the outside due to the sound absorbing effect of the intake filter.

Also, a suction communication hole 6D is opened on the side surface (upper side surface in FIG. 1) of the motor case 6A. In the present embodiment, the suction communication hole 6D is arranged in the X-axis direction at a position overlapping the range in which the armature 7 of the linear motor 5 is arranged. That is, the intermediate suction passage 16 is connected to a position that overlaps with the range in which the stator (the armature 7 in this embodiment) is arranged in the X-axis direction (the reciprocating direction of the mover 8).

A pipe joint 27 that connects the intermediate intake passage 26 is provided in the suction communication hole 6D. On the other hand, the cylinder head 17 has a head suction port 17A opened in a direction orthogonal to the X axis, and a pipe joint 27 is provided at the head suction port 17A. An intermediate suction passage 26 is connected to the pipe joint 27 of the suction communication hole 6D and the pipe joint 27 at the head suction port 17A. Thus, the intermediate suction passage 26 is provided between the suction valve 14 provided at the inlet of the compression chamber 12B and the spring accommodating space V2.

The intermediate suction passage 26 connects the suction communication hole 6D of the motor case 6A and the head suction port 17A of the cylinder head 17, and introduces the air sucked into the motor case 6A into the suction space 18. The intermediate suction passage 26 is arranged outside the armature (stator) 7, the motor case 6A and the cylinder 12 in a direction orthogonal to the X axis so as to bypass the cylinder 12, and the suction communication hole 6D (spring accommodating hole). The space V2) and the head suction port 17A (suction space 18) are constituted by a passage member (pipe).

As shown in FIG. 1C, the armature 7 that constitutes the stator has notches 7SA and 7SB formed on its outer peripheral surface. In the present embodiment, the cutouts 7SA, 7SB are provided at two positions with a circumferential interval. The outer peripheral surface 7SC between the two adjacent cutout portions 7SA and 7SB is in contact with the inner peripheral surface of the motor case 6A. Gaps V7 and V8 are formed between the armature 7 and the inner peripheral surface of the motor case 6A at the portions where the cutouts 7SA and 7SB are provided, and the pipe joint 27 is arranged on the one gap V7 side. .. That is, the intermediate suction passage 26 is connected so as to communicate with the gap V7.

The operation of the linear compressor of this embodiment will be described.

First, when a current is supplied (energized) to the coil 7B of the armature 7 of the linear motor 5, the permanent magnet 8B of the mover 8 receives a thrust force in the axial direction, and the entire mover 8 is driven along the X-axis direction. .. At this time, each core 7A of the armature 7 and each permanent magnet 8B of the mover 8 generate a magnetic attraction force and a repulsive force between the coils 7B by energizing each coil 7B. The armature 8 moves in the motor case 6A along the X-axis direction between the pair of armatures 7 arranged in the Y-axis direction.

Further, at this time, in the spring 10, a spring force is always generated in a direction in which the mover 8 is kept at the neutral position due to the springs 10A and the springs 10B that are alternately compressed. By applying an alternating current to each coil 7B so as to cooperate with this spring force, the mover 8 is driven so as to repeat the reciprocating motion in the X-axis direction.

The thrust resulting from the reciprocating movement of the mover 8 is transmitted to the piston 13 arranged in the cylinder 12 of the compression unit 11. The piston 13 repeatedly reciprocates in the cylinder 12 in the axial direction (X-axis direction) to perform compression operation. That is, in the suction stroke, the compression chamber 12B in the cylinder 12 tends to have a negative pressure, and the intake valve 14 opens accordingly. As a result, the suction space 18 and the compression chamber 12B communicate with each other through the suction hole 15A (see FIG. 4) provided in the head plate 15. Therefore, the air in the motor case 6A is sucked into the suction space 18 through the intermediate suction passage 26, and the outside air further flows into the motor case 6A from the suction port 24 of the motor case end plate 6C. That is, the outside air sucked through the suction silencer 25 is sucked into the motor case 6A through the suction port 24, further passes through the intermediate suction passage 26, the suction space 18, and the suction hole 15A into the compression chamber 12B. Be sucked.

On the other hand, in the compression stroke, the suction valve 14 is closed, and the displacement of the piston 13 in the cylinder 12 increases the pressure in the compression chamber 12B. Then, when the pressure in the compression chamber 12B becomes higher than the valve opening pressure of the discharge valve 16, the discharge valve 16 opens. As a result, the compressed air generated in the compression chamber 12B is discharged toward the discharge space 19 in the cylinder head 17. After that, the gas is discharged to the outside of the compressor through the discharge port 17B and is supplied to the device connected to the linear compressor.

The propagation of noise generated during operation of the linear compressor according to this embodiment will be described.

The most dominant noises of the compressor during operation are the valve operating noises of the discharge valve 16 and the suction valve 14 and the fluid noises when air passes through the respective valves. Of these, the discharge side path is connected to the equipment outside the compressor from the discharge port 17B, so noise due to the discharge valve 16 is unlikely to leak to the outside, but the suction side path is the suction silencer attached to the suction port 24. Since 25 communicates with the external space, noise propagates to the external space. That is, the noise caused by the suction valve 14 propagates in the air suction path in the opposite direction to the air flow, and propagates from the suction space 18 to the motor case 6A through the intermediate suction passage 26. The noise propagated to the motor case 6A further propagates to the suction silencer 25 through the suction port 24 and propagates to the outside.

At this time, the sound wave transmission path is constituted by the first space V1, the second space V2, and the third space V3.

The first space V1 is a space formed by the passage space of the intermediate suction passage 26 and the space formed between the armature 7 that is the stator and the inner peripheral surface of the motor case 6A. The first space V1 is the space (volume _{_{_{V 1 = S 1 × L 1}}} ) having the cross-sectional area _{S 1} and path length _{L 1.} Of the space formed between the armature 7 and the inner peripheral surface of the motor case 6A, the space forming the first space V1 is the second space from the portion to which the intermediate suction passage 26 (pipe joint 27) is connected. The part on the V2 side.

Here, among the spaces formed between the armature 7 and the inner peripheral surface of the motor case 6A, the space forming the first space V1 will be referred to as a stator outer peripheral passage space V7. The stator outer peripheral passage space V7 is defined by a gap V7 formed between the armature 7 and the inner peripheral surface of the motor case 6A by the cutout portion 7SA. Since the outer peripheral surface 7SC of the armature 7 is in contact with the inner peripheral surface of the motor case 6A between the two adjacent cutout portions 7SA and 7SB, the gap V7 is in communication with the other gap V8. Therefore, the cross-sectional area of the stator outer peripheral passage space V7 can be reduced. In this case, as the passage cross-sectional area of the first space V1 is S _1, the cross-sectional area of the stator outer periphery passage space V7 is configured to be the same size as the cross-sectional area S ₁ of the intermediate suction passage 26 Is desirable.

The second space V2 is a space formed within the range of the length L ₂ of the motor case 6A in FIG. 1B, and the spring 10 is arranged in the second space V2. Therefore, the second space V2 may be referred to as a spring arrangement space. The second space V2 is a space (space volume V ₂ ) having a case length L ₂ and an equivalent cross-sectional area S ₂ . Here, since the spring 10 and the like are arranged in the second space V2, the cross-sectional area S ₂ of the second space V2 has a size excluding the area occupied by the spring 10 and the like. Therefore, the sectional area S ₂ of the second space V2 is called an equivalent sectional area or an effective sectional area. That is, the equivalent cross-sectional area S ₂ is a cross-sectional area of a substantial space obtained by removing the area occupied by the spring 10 and the like from the cross-sectional area of the motor case 6A forming the second space V2. Hereinafter, the cross-sectional area of this substantial space will be simply referred to as a space cross-sectional area for description.

Third space V3 is the space formed suction port 24 having a cross-sectional area _{S 3} and the passage length _{L 3} (volume _{_{_{V 3 = S 3 × L 3}}} ).

In this embodiment, the substantial volume of the second space V2 is greater than the volume V ₃ volume V ₁ and the third space V3 of the first space V1. In this case, the space cross-sectional area S ₂ in the second space (spring accommodating space) V ₂ perpendicular to the reciprocating direction (X-axis direction) of the mover 8 is the passage cross-sectional area S ₁ of the intermediate suction passage 26 and the suction port 24. Is larger than the cross-sectional area S ₃ of the passage.

Then, the sound wave propagates from the first space V1 to the second space V2 having a larger space volume and passage cross-sectional area than the first space V1, and further from the second space V2 to the space volume and passage disconnection than the second space V2. It passes through the third space V3 having a small area. That is, in such a sound wave transmission path, when the sound wave propagates from the first space V1 to the second space V2, the cross-sectional area of the transmission path increases, and when the sound wave propagates from the second space V2 to the third space V3. , The cross-sectional area of the transmission path becomes smaller. In such a transmission path, the second space V2 in the motor case 6A plays the role of a reactive expansion silencer, and noise is reduced due to the acoustic impedance of the connection portion of each space in the transmission path. It has the effect of reducing the noise that propagates to.

Note that the cross-sectional areas of the first space V1, the second space V2, and the third space V3 may be referred to as the space cross-sectional area or the passage cross-sectional area. Here, the passage cross-sectional area means the cross-sectional area of the intake passage, and the space cross-sectional area is used as a name including the passage cross-sectional area. The spatial cross-sectional areas of the first space V1 and the third space V3 are areas in a cross section perpendicular to the intake air flow direction, and the spatial cross-sectional area of the second space V2 is an area in a cross section perpendicular to the X axis.

FIG. 5 is a diagram showing the muffling characteristics of the linear compressor of the first embodiment. FIG. 5 shows the result of obtaining the silencing effect of the expansion silencer in the sound wave transmission path of the present embodiment. The horizontal axis shows the noise frequency and the vertical axis shows the silencing effect.

In this embodiment, the muffling effect has a negative value in the frequency band up to 0-400 Hz, and there is no muffling effect, but a maximum muffling effect of about 10 dB is exhibited in the frequency band up to 400-1250 Hz. At 1250Hz, the muffling effect becomes zero once, but at a frequency band higher than that, the muffling effect appears again. However, in the region above 1580 Hz indicated by the dotted line in the figure, the assumption that sound waves are transmitted as plane waves is no longer valid, and although the characteristics can be expressed by calculation, the silencing effect does not appear.

FIG. 6 is a diagram showing an example of noise measurement results of the linear compressor of the first embodiment. The horizontal axis represents noise frequency and the vertical axis represents sound pressure level. Note that FIG. 6 also shows the sound pressure level of the conventional structure in order to make the effects of the embodiment easier to understand.

The conventional structure has a structure in which a suction silencer is connected to the suction space 18, and the suction space 18 does not have an expansion portion having an expansion-type silencer effect between the suction silencer and the intake silencer. The noise of the conventional structure was 67 dB overall. On the other hand, with the configuration of the present embodiment, the noise value is 59 dB, and a noise reduction effect of about 7 dB is exhibited. Looking at each frequency, it can be seen that the configuration of the present example reduces noise in the 300 to 1800 Hz band as compared with the conventional structure, and exhibits characteristics close to the silencing effect shown in FIG.

The temperature rise of the linear compressor according to this embodiment will be described.

In the compressor, when the motor is energized during operation, the coil 7B of the armature 7 generates heat, and in the compression chamber 12B of the compression unit 11, the cylinder 12 generates heat due to the temperature rise accompanying the compression of air. In addition, heat is generated due to friction on the side surface of the piston 13 and sliding parts such as bearings, but heat generation of the coil 7B and the cylinder 12 is dominant. This heat generation amount is basically radiated by heat transfer with the outside air.

FIG. 7 is a diagram showing a temperature change of the linear compressor of the first embodiment. FIG. 7 shows changes in coil temperature and cylinder temperature from the start of operation in the conventional compressor and the compressor of the present embodiment. The horizontal axis represents the time elapsed from the start of operation, and the vertical axis represents the temperatures of the coil and the cylinder.

In the conventional structure, the motor inside the motor case does not come into direct contact with the outside air, so the motor temperature easily rises and the coil temperature rises significantly compared to other parts. Therefore, in the case of a compressor having a conventional structure, it is necessary to mount a fan for cooling the motor and accelerate the heat transfer around the motor to lower the coil temperature. However, in the compressor of the present embodiment, the outside air sucked through the suction silencer 25 is sucked into the motor case 6A through the suction port 24 and exchanges heat with the coil 7B, and then the intermediate suction passage 26, Since it is configured to be sucked into the compression chamber 12B through the space 18 and the suction hole 15A, the temperature rise of the coil 7B can be suppressed and the temperature can be suppressed low. Therefore, the compressor of this embodiment does not need to be equipped with a self-cooling fan for cooling the motor.

As described above, the linear compressor of the present embodiment can reduce the noise propagating from the suction pipe to the outside by using the motor case 6A as the expansion silencer of the suction pipe, and further cools the linear motor 5 by the suction air. It is possible to provide an air compressor that can reduce heat generation, has high quietness, is small, and is highly reliable.

Further, in this embodiment, since the intermediate suction passage 26 is formed as a passage for exclusive use of intake air outside the armature (stator) 7, the motor case 6A and the cylinder 12 in the direction orthogonal to the X axis, the design of its cross-sectional area is provided. High degree of freedom. For this reason, it is easy to make the relationship of the space cross-sectional area between the intermediate suction passage 26 and the second space (spring accommodation space) V2 appropriate to the expansion silencer.

According to this embodiment, in addition to the effects described above, the following effects can be obtained.
Since the mover 8 has a flat plate shape, the motor can be made smaller than the cylindrical shape.
-By bringing the back side (opposite side of the core) of the armature 7 that is the stator into contact with the motor case 6A, the heat of the motor can be transferred to the motor case 6A and efficiently dissipated to the outside air, and the compressor body can be made smaller Can be converted. In this case, assuming that the reciprocating direction of the plate-shaped mover 8 is the X direction and the direction of the magnetic flux of the magnet is the Y direction, the contact with the motor case 6A is the Y direction.

[Example 2]
Next, a linear compressor according to a second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a cross-sectional view showing the configuration of the linear compressor of the second embodiment. The same components as those in the first embodiment described above are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted. The configuration different from that of the first embodiment will be described below.

In this embodiment, similarly to the first embodiment, the mover 8 is formed in a flat plate shape, and the reciprocating direction (X axis direction) and the flat plate thickness direction (Y axis direction) are horizontal directions. It is arranged in (vertical arrangement).

As shown in FIG. 8, the suction communication hole 6D that is opened on the side surface (the upper side surface in FIG. 8) of the motor case 6A connected to the intermediate suction passage 26 shown in the first embodiment is located on the rear side of the linear motor 5. It is provided on the upper part of 10. That is, the suction communication hole 6D is arranged so as to overlap the range in which the spring 10 is arranged in the X-axis direction. Further, in this embodiment, the linear compressor is supported by a support spring (vibration isolation spring) 81 having an anti-vibration effect. For this purpose, the linear motor 5 and the compression unit 11 are provided with a base member 80 in the lower portion in the vertical direction (lower portion in the direction of gravity), and the base member 80 is supported by the support spring 81. Further, the intermediate suction passage 26 is arranged in a range that overlaps the support spring 81 in the vertical direction. That is, the intermediate suction passage 26 is arranged vertically between the lower end of the support spring 81 and the lower portions of the linear motor 5 and the compression portion 11 which form the compressor body. In other words, the intermediate suction passage 26 is arranged between the upper end and the lower end of the support spring 81. The other configuration is the same as that of the first embodiment.

In the present embodiment, the suction communication hole 6D opened on the side surface of the motor case 6A connected to the intermediate suction passage 26 is provided in a range overlapping with the range in which the spring 10 is arranged. That is, the intermediate suction passage 26 is connected to a position that overlaps the range in which the spring 10 is arranged in the X-axis direction (the reciprocating direction of the mover 8).

In this embodiment, the intermediate suction passage 26 directly communicates with the second space V2. That is, the first space V1 is formed by the intermediate suction passage 26, and the gap 7SA is not included in the first space V1. In this embodiment, since it is difficult for the intake air to flow to the outer peripheral side of the armature 7, the amount of heat exchange between the intake air and the coil 7B is suppressed, and the coil temperature rises by about 5°C. However, conversely, the temperature of the suction air sucked into the suction space 18 through the intermediate suction passage 26 decreases and the density of the suction air increases, so that the compression flow rate increases and the efficiency also increases.

In the present embodiment, although the coil temperature slightly rises, it is possible to provide a small-sized air compressor having higher efficiency, higher quietness, and higher efficiency. The effect that the armature 7 arranged inside the motor case 6A is cooled by the intake air is the same as that of the first embodiment, although there is a degree of difference.

In the present embodiment, since the intermediate suction passage 26 is configured as a passage for exclusive use of intake air outside the armature (stator) 7, the motor case 6A and the cylinder 12 in the direction orthogonal to the X axis, the passage of the intermediate suction passage 26. High degree of freedom in designing the cross-sectional area. Further, in this embodiment, unlike the first embodiment, the stator outer peripheral passage space V7 is not included in the first space V1, so that the first space V1 has a simple shape and the expansion silencer can be easily designed.

In the present embodiment, the support body 81 is arranged below the linear motor 5 and the compression section 11 which form the compressor body in the vertical direction. The intermediate suction passage 26 is disposed on the same side as the support portion of the compressor body supported by the support body 81. In this embodiment, the support 81 is composed of a coil spring (support spring), but it may be composed of a vibration insulator or a vibration isolation mount. The support 81 may be arranged above the compressor body. When the support body 81 is arranged on the upper side of the compressor body, the compressor body may be supported in a state of being suspended by the support body 81, or together with the support body 81 arranged on the lower side of the compressor body, The compressor body may be supported from both the lower side and the upper side of the compressor body.

In the configuration shown in FIG. 8, the end surface of the permanent magnet 8B facing the magnetic pole of the core 7A is arranged along the vertical direction. That is, the Z direction is the vertical direction, and the mover 8 is in the vertical arrangement. Since the intermediate suction passage 26 is arranged in the range that overlaps with the support spring 81 in the vertical direction, the height dimension of the linear compressor can be reduced, and the size increase in the vertical direction is suppressed.

The support 81 can be applied to the first embodiment, and the arrangement relationship between the support 81 and the intermediate suction passage 26 described in the first embodiment in the first embodiment can be adopted. The support 81 will be referred to as a support spring in the following description.

In the present embodiment, the configuration in which the compressor main body is vertically arranged (vertical arrangement) has been described, but the arrangement can be changed to the horizontal type by changing the arrangement of the support spring 81.

[Example 3]
Next, a linear compressor according to a third embodiment of the present invention will be described with reference to FIGS. 9A, 9B and 9C. FIG. 9A is a sectional view parallel to the X axis, showing the configuration of the linear compressor of the third embodiment. 9B is a sectional view parallel to the X axis of the linear compressor, which is different from FIG. 9A. 9C is a sectional view taken along line IX-IX of FIG. 9B. The same components as those in the first and second embodiments described above are designated by the same reference numerals as those in the first and second embodiments, and description thereof will be omitted. The configuration different from that of the embodiment will be described below.

In this embodiment, as shown in FIG. 9A, the intermediate suction passage 26 shown in the first and second embodiments is not provided outside the compressor but is provided inside the compressor.

The intermediate suction passage 26 is arranged inside the motor case 6A, and serves as a suction passage that connects the first space (spring accommodation space) V1 with the suction space (non-compression chamber 12A) on the back surface of the piston 13. Further, the piston 13 is provided with a communication hole 13C that connects the non-compression chamber 12A and the compression chamber 12B, and a suction valve 14 that covers the communication hole 13C so as to be opened and closed. The suction valve 14 opens the communication hole 13C in the suction stroke of the compression portion 11 (piston 13) and connects the non-compression chamber 12A and the compression chamber 12B. In the compression stroke of the compression portion 11 (piston 13), the suction valve 14 closes the communication hole 13C, and the compression chamber 12B is shut off from the non-compression chamber 12A.

The thrust resulting from the reciprocating movement of the mover 8 is transmitted to the piston 13 in the compression section 11 (cylinder 12). The piston 13 repeatedly reciprocates in the cylinder 12 in the axial direction (X-axis direction) to perform compression operation. That is, in the suction stroke of the piston 13, the compression chamber 12B in the cylinder 12 tends to have a negative pressure, and the suction valve 14 opens accordingly. As a result, the non-compression chamber 12A and the compression chamber 12B communicate with each other through the communication hole 13C provided in the piston 13. Therefore, in the non-compression chamber 12A in the cylinder 12, outside air passes through the suction silencer 25 and flows into the motor case 6A from the suction port 24 of the motor case 6A, and a gap between the motor case 6A and the linear motor 5 is generated. The (space) V7 flows into the non-compression chamber 12A from the communication port 7E provided in the holder 7C of the linear motor 5. The air flowing into the non-compression chamber 12A is sucked into the compression chamber 12B via the communication hole 13C of the piston 13.

On the other hand, in the compression stroke of the piston 13, when the suction valve 14 is closed and the communication hole 13C of the piston 13 is closed, compression is performed by displacement of the piston 13 in the cylinder 12 (displacement in which the compression chamber 12B narrows). The pressure in the chamber 12B rises. Then, when the pressure in the compression chamber 12B becomes higher than the valve opening pressure of the discharge valve 16, the discharge valve 16 opens. As a result, the compressed air generated in the compression chamber 12B is discharged toward the discharge space 19 in the cylinder head 17. Thereafter, the compressed air is supplied to the device connected to the linear compressor via the discharge port 17B.

The noise propagation of the linear compressor according to this embodiment will be described.

The noise caused by the suction valve 14, which is dominant among the noises of the compressor in operation, propagates in the suction path of air in the opposite direction to the flow of air, and flows through the communication hole 13C of the piston 13 into the non-compression chamber 12A. To the motor case 6A through the communication port 7E provided in the holder 7C of the linear motor 5. This noise is further transmitted to the suction silencer 25 through the suction port 24 and propagates to the outside.

In this embodiment, as shown in FIG. 9A, an intermediate suction passage 26 is formed between the communication port 7E and the second space V2, and the first space V1 is composed of the communication port 7E and the intermediate suction passage 26. .. That is, the suction passage that connects the linear motor 5 and the suction space (the non-compression chamber 12A) on the back surface of the piston 13 includes the communication port 7E in addition to the intermediate suction passage 26.

The first space V1 is the space (volume _{_{_{V 1 = S 1 × L 1}}} ) having the cross-sectional area _{S 1} and path length _{L 1.} The intermediate suction passage 26 is formed on the outer peripheral side of the armature 7 forming the stator and inside the motor case 6A in the direction orthogonal to the X axis. It is desirable that the opening area of the communication port 7E be the same as the passage cross-sectional area of the intermediate suction passage 26. Therefore, the opening area of the communication port 7E is formed smaller than the cross-sectional area (cross-sectional area perpendicular to the X axis) of the non-compression chamber 12A formed on the rear side of the piston 13.

The second space V2 and the third space V3 are similar to those in the first and second embodiments, and the relationship between the volume of the first space V1, the second space V2, and the third space V3 and the space cross-sectional area is the first and second embodiments. It is constructed in the same way as.

Also in the present embodiment, as in the first and second embodiments, the second space V2 in the motor case 6A plays the role of a reactive expansion silencer, and noise is generated by the acoustic impedance of the connection part of each space in the transmission path. Is reduced, and the noise transmitted to the outside is reduced.

As described above, in the linear compressor of this embodiment, the motor case 6A can be used as an expansion silencer for the suction pipe without providing the intermediate suction passage 26 outside the motor case 6A. The noise leaking to the outside can be reduced. Further, the linear compressor of the present embodiment can reduce heat generation by cooling the linear motor 5 with suction air. Further, by disposing the intermediate suction passage 26 inside the motor case 6A, it is possible to suppress the size increase of the linear compressor in the direction orthogonal to the X axis. As a result, the linear compressor of the present embodiment can provide an air compressor with high quietness, smaller size, and higher reliability.

Also in the present embodiment, the compressor main body is arranged vertically and the intermediate suction passage 26 is arranged on the side where the support spring 81 is located in the Z direction, so that the increase in size in the direction perpendicular to the X axis can be suppressed. .. In this case, it is advisable to provide the wire connection portion of the coil in the Z direction. A space is provided between the armature 7 and the motor case 6A for the coil connecting portion, and this space can be used as the intermediate suction passage 26.

In this embodiment, the configuration in which the compressor main body is vertically arranged (vertical arrangement) has been described, but by changing the arrangement of the support spring 81, it is possible to arrange the compressor horizontally.

[Example 4]
FIG. 10 is a configuration diagram of an embodiment of a refrigerator 2001 using the linear compressor according to the present invention.

Refrigerator 2001 is provided with a left and right double-door split refrigerating compartment door 2002a on the front side of refrigerating compartment 2002, and on the front side of ice making compartment 2003, upper freezing compartment 2004, lower freezing compartment 2005, and vegetable compartment 2006. , A drawer type ice making chamber door 2003a, an upper freezing chamber door 2004a, a lower freezing chamber door 2005a, and a vegetable chamber door 2006a, respectively.

A machine room 2020 is provided on the back side of the vegetable room 2006, and a linear compressor 2024 is arranged in the machine room 2020. Further, an evaporator chamber 2008 is provided on the back side of the ice making chamber 2003, the upper freezing chamber 2004, and the lower freezing chamber 2005, and the evaporator 2007 is provided in the evaporator chamber 2008. In the refrigerator 2001, in addition to the compressor 2024 and the evaporator 2007, a radiator (not shown), a capillary tube as a pressure reducing means, a three-way valve, and the like are connected by a refrigerant pipe to form a refrigeration cycle 2030.

In this embodiment, the linear compressor according to any one of the above-described embodiments is adopted as the compressor 2024 that constitutes the refrigeration cycle 2030 of the refrigerator 2001. The refrigerator 2001 of the present embodiment can prevent the compressor constituting the refrigeration cycle 2030 from increasing in size by adopting the linear compressor of the above-described embodiment. Further, it becomes possible to secure a large space for the refrigerating room and the freezing room, and it is possible to provide a large-capacity refrigerator without increasing the outer dimensions.

[Example 5]
FIG. 11 is a configuration diagram of an embodiment of a vehicle air suspension 3004 using the linear compressor according to the present invention.

In this embodiment, a case where a vehicle air suspension is mounted on a vehicle such as a four-wheeled vehicle will be described as an example.

The vehicle body 3002 constitutes the body of the vehicle 3001. On the lower side of the vehicle body 3002, a total of four wheels 3003 including left and right front wheels and left and right rear wheels are provided. The air suspension 3004 includes four air springs 3005 provided between the vehicle body 3002 and each wheel 3003, an air compressor (linear compressor) 3006, a valve unit 3008, and a controller 3011. The air suspension 3004 adjusts the vehicle height by supplying and discharging compressed air from the air compressor 3006 to and from each air spring 3005.

In this embodiment, as the air compressor 3006, any one of the linear compressors of the above-described embodiments is adopted. The air compressor 3006 is connected to the valve unit 3008 through a supply/discharge pipe line (pipe) 3007. The valve unit 3008 is provided with four supply/discharge valves 3008a, which are electromagnetic valves and are provided for each wheel 3003. A branch pipe (pipe) 3009 is provided between the valve unit 3008 and the air spring 3005 of each wheel 3003. The air spring 3005 is connected to the air compressor 3006 via a branch conduit 3009, a valve 3008a, and a supply/discharge conduit 3007. Then, the valve unit 3008 opens and closes the supply/exhaust valve 3008a in response to a signal from the controller 3011, thereby supplying/discharging compressed air to/from each air spring 3005 to adjust the vehicle height.

In the present embodiment, it is possible to prevent the air compressor 3006 forming the air suspension 3004 from becoming large. Then, the mounting space of the air compressor 3006 in the vehicle 3001 can be reduced, and the degree of freedom in arranging the air compressor 3006 is increased.

According to the embodiment of the present invention, a reciprocating compressor (referred to as a linear compressor) that uses a linear motor of a direct-acting type among reciprocating (reciprocating) compressors is used as the compressor type. Since a crank mechanism is not required, the compressor (linear compressor) can be made smaller and have a lower profile. Further, in the embodiment according to the present invention, noise from the suction pipe can be reduced by using the motor case as an expansion silencer of the suction pipe, and the size of the compressor can be reduced and the height can be reduced by integrating the motor case and the silencer. To be achieved. Further, by cooling the linear motor with the intake air, heat generation is reduced, and it is possible to provide a compact, highly quiet and highly reliable compressor. Further, in the linear compressor according to the present invention, in addition to the cooling effect related to the structure of the intermediate suction passage 26, the temperature rise of the suction air can be further reduced due to the heat radiation effect described in the first embodiment, and the intermediate suction passage can be further reduced. Even if it is provided, a compact compressor is possible without increasing the size of the compressor.

The present invention is not limited to the above-mentioned embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the configurations. Further, a part of the configuration of a certain embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of a certain embodiment. Further, with respect to a part of the configuration of each embodiment, other configurations can be added/deleted/replaced.

5... Linear motor, 6... Casing, 7... Armature (stator), 8... Mover, 10 (10A, 10B)... Spring, 11... Compression part, 12... Cylinder, 12A... Non-compression chamber (suction space) , 12B... Compression chamber, 13... Piston, 13C... Communication hole, 14... Suction valve, 17... Cylinder head, 18... Suction space, 24... Suction port, 25... Sound absorbing silencer, 26... Intermediate suction passage, 2001... Refrigerator , 2024... Compressor (linear compressor), 2030... Refrigeration cycle, 3004... Air suspension, 3005... Air spring, 3006... Air compressor (linear compressor), V1... First space, V2... Second space (spring) (Accommodation space), V3... third space.

Claims

A compression unit that compresses the air in the compression chamber by the reciprocating motion of the piston, and a linear motor that drives the piston,
The linear motor is a stator that drives the mover by applying a magnetic force between the mover that is connected to the piston and reciprocates, a vibration spring that can vibrate with the mover, and the mover. When,
In a linear compressor equipped with
A housing for accommodating the stator of the linear motor is provided on one end side, an air inlet is provided at the other end, and a spring accommodating space for accommodating the vibration spring is formed between the stator and the inlet. Equipped with a casing,
An intermediate suction passage is provided between the suction valve provided at the inlet of the compression chamber and the spring accommodating space,
A linear compression characterized in that a space sectional area in the spring accommodating space perpendicular to the reciprocating direction of the mover is larger than a passage sectional area of the intermediate suction passage and a passage sectional area of the suction port. Machine.
The linear compressor according to claim 1,
The linear compressor according to claim 1, wherein the intermediate suction passage is arranged outside the stator.
The linear compressor according to claim 2,
A support body that supports a compressor body configured by the compression unit and the linear motor,
The linear compressor, wherein the intermediate suction passage is disposed on the same side as the support portion of the support body.
The linear compressor according to claim 1,
A support body that supports a compressor body configured by the compression unit and the linear motor,
The mover is formed in a flat plate shape, and is arranged in a direction in which the reciprocating direction and the flat plate thickness direction are horizontal.
The linear compressor, wherein the support portion of the compressor body by the support body is disposed above or below the compressor body.
The linear compressor according to claim 1,
A cylinder head having a suction space communicating with the compression chamber via the suction valve is provided at an end of the cylinder forming the compression chamber on the side opposite to the side where the linear motor is provided,
The linear compressor is characterized in that the intermediate suction passage is arranged outside the casing to communicate the suction space and the spring accommodating space.
The linear compressor according to claim 5,
The linear compressor is characterized in that the intermediate suction passage is connected to a position where the intermediate suction passage overlaps a range in which the stator is arranged in the reciprocating direction of the mover.
The linear compressor according to claim 5,
The linear compressor is characterized in that the intermediate suction passage is connected to a position in the reciprocating direction of the mover so as to overlap a range in which the vibration spring is arranged.
The linear compressor according to claim 5,
The intermediate suction passage is arranged inside the casing, and connects the spring accommodating space and a suction space formed on the back surface of the piston,
A linear compressor characterized in that the piston is provided with a communication hole that allows the suction space and the compression chamber to communicate with each other, and the communication hole is covered by the suction valve so as to be opened and closed.
The linear compressor according to claim 1,
A linear compressor characterized in that a sound absorbing silencer is provided at the suction port.
In an air suspension including an air spring and an air compressor that supplies and discharges compressed air to and from the air spring,
An air suspension comprising the linear compressor according to claim 1 as the air compressor.
In a refrigerator equipped with a refrigeration cycle,
A refrigerator comprising the linear compressor according to claim 1 as a compressor constituting the refrigeration cycle.