JP3540727B2 - Linear compressor - Google Patents

Description

[0001]
[Industrial applications]
The present invention relates to a linear compressor, and more particularly, to a linear compressor which compresses gas by, for example, reciprocating a piston inserted into a cylinder by a linear motor and supplies the compressed gas to the outside.
[0002]
[Prior art]
Generally, this type of linear compressor includes a piston inserted reciprocally so as to form a compression chamber in a cylinder, and a linear motor that relatively moves the cylinder and the piston so that the piston reciprocates in the cylinder. For example, by reciprocating a piston by driving of the linear motor, for example, a refrigerant gas sucked into a compression chamber is compressed and discharged (for example, a second embodiment disclosed in Japanese Patent Application Laid-Open No. 2000-110718A). See example).
[0003]
By the way, when the piston reciprocates in the cylinder to compress the gas in the compression chamber, heat of compression is generated, and this heat adversely affects the peripheral portion including the cylinder. Further, in a linear motor, for example, even in a gap portion of a stator core in which a movable body moves, air undergoes a compressive action as the movable body reciprocates to generate heat.
[0004]
[Problems to be solved by the invention]
As described above, in a state in which heat is generated in various places due to the compression operation in the linear compressor, the ambient temperature of the portion where the permanent magnets are disposed becomes high, causing the permanent magnets to be demagnetized and the performance of the linear motor to deteriorate. Accordingly, there is a problem that the performance of the compressor is also reduced.
[0005]
In addition, the components of the compressor thermally expand due to the effects of the above-described heat, and in particular, the clearance between the cylinder and the piston, which requires high clearance accuracy, changes, and the piston cannot smoothly reciprocate. Gas leakage occurs in the compression chamber, and the compression efficiency is reduced.
[0006]
As a countermeasure for this, for example, as disclosed in Japanese Patent Application Laid-Open No. H6-159837, a ventilation hole and a radiation fin are integrally formed in a cylinder, or a separate blowing mechanism is provided, but the structure is complicated. And cost.
[0007]
SUMMARY OF THE INVENTION Therefore, a main object of the present invention is to provide a linear compressor capable of suppressing an adverse effect on a motor section due to heat generated in each section in the compressor with a simple configuration.
[0008]
[Means for Solving the Problems]
The present invention relates to a motor unit having a movable portion for driving a piston shaft in the axial direction, a piston fixed to the piston shaft outside the motor unit in the axial direction, a compression chamber fixed to the fixed portion and receiving the piston to form a compression chamber. A linear compressor including a cylinder and a leaf spring disposed around the cylinder and having one end fixed to a movable portion and the other end fixed to a fixed portion.
[0009]
[Action]
The ambient temperature surrounding the cylinder is about to rise as the piston reciprocates in the cylinder by the linear motor to perform a compression action, but the leaf spring disposed around the cylinder is driven by the movable part of the motor unit. As a result, the leaf spring vibrates, and the surrounding air is fueled to generate an air flow. Further, it is possible to easily cool oil or the like dropped from an axial oil supply groove provided on the outer peripheral surface of the cylinder.
[0010]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, while the compression efficiency of a linear compressor improves, generation | occurrence | production of heat can be suppressed and the thermal expansion of each component of a compressor is suppressed, and size reduction of a linear compressor can be achieved.
[0011]
The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.
[0012]
【Example】
As shown in FIGS. 1 and 2, a linear compressor 10 according to an embodiment of the present invention includes a motor unit 16 having a linear movable portion 14 for driving a piston shaft 12 in an axial direction, and an axial direction of the motor unit 16. It includes a compressor unit 24 having a cylindrical cylinder 22 that receives a piston 18 externally connected to the piston shaft 12 to form a compression chamber 20.
[0013]
The motor unit 16 is formed by an inner yoke 26 and an outer yoke 30 having a gap 28 between the inner yoke 26, and has a bottomed annular stator core (magnetic frame) 32 that is open on one side. Includes an annular permanent magnet 34 mounted on the inner surface.
[0014]
The permanent magnet 34 and the stator core 32 constitute a magnetic circuit as a linear motor, and the magnetic circuit generates a magnetic field of a predetermined strength in the gap 28 between the permanent magnet 34 and the inner surface of the outer yoke 30. I try to make it. The bottomed side of the stator core 32 is fixed to a cylindrical housing 36.
[0015]
Further, the linear movable portion 14 is fixed to the piston shaft 12 at the center of a disk portion 38a provided on the piston 18 side, and the annular skirt portion 38b passes through an insertion hole (not shown) provided in the stator core 32. The movable body 38 includes a bottomed cylindrical movable body 38 made of a synthetic resin and located in the cavity 28, and an electromagnetic coil 40 fixed to the annular skirt 38 b of the movable body 38 so as to face the permanent magnet 34.
[0016]
A cylinder head 48 is screwed and mounted on a column 50 extending from the cylindrical housing 36 via a valve plate 46 provided with a suction valve 42 and a discharge valve 44 on an end surface of the cylindrical cylinder 22 constituting the compressor unit 24. I have. The cylinder head 48 is integrally formed with a suction chamber 52 and a discharge chamber 54 which are appropriately communicated with the compression chamber 20 via a suction valve 42 and a discharge valve 44, and an external cooling circuit (not shown) for performing a cooling action is connected to both chambers. Is done.
[0017]
In the space portion 56 formed between the disk portion 38a of the movable body 38 and the cylinder head 48, five annular leaf springs 58, 58,. (For example, 3 mm). The inner edge portions 58a of these annular leaf springs 58 are connected by a connecting member 60 and fixed to the disk portion 38a of the movable body 38 with screws, and the outer edge portions 58b are fixed to the cylindrical housing 36. The piston 18 is supported by the annular leaf spring 58 via the piston shaft 12 so as to be able to reciprocate.
[0018]
The annular leaf spring 58 is formed by punching a stainless steel plate having a thickness of, for example, 2 mm into a ring shape, and forms a plurality of, for example, about three spiral slit grooves in order to have more elasticity as necessary. You may.
[0019]
As shown in FIG. 2, an oil supply groove 62 having a substantially U-shaped cross section is formed in the upper surface of the cylindrical cylinder 22 in the axial direction, and eight air holes 64 are formed in the disk portion 38a of the movable body 38. 64,...
[0020]
Next, an outline of the operation in the above configuration will be described.
[0021]
First, when an alternating current of a predetermined frequency (for example, 60 Hz) is applied to the electromagnetic coil 40 via a lead wire (not shown), the electromagnetic coil 40 and the movable body 38 are actuated by the action of a magnetic field passing through the gap 28 of the stator core 32. Drive. As a result, the piston 18 reciprocates in the cylindrical cylinder 22 via the piston shaft 12, and the refrigerant gas and the like sucked into the compression chamber 20 via the suction chamber 52 and the suction valve 42 of the cylinder head 48 are compressed. The refrigerant gas becomes high-pressure refrigerant gas and is discharged to the external cooling circuit via the discharge valve 44 and the discharge chamber 54 of the cylinder head 48. The annular leaf spring 58 allows the piston shaft 12 and the piston 18 to reciprocate stably without being twisted.
[0022]
On the other hand, due to the reciprocating motion of the piston shaft 12, the five annular leaf springs 58 fixed to the disk portion 38a of the movable body 38 reciprocate right and left, and the air in the space 56 surrounding the cylindrical cylinder 22 The hollow cylinder of the stator core 32 in which the piston shaft 12 is disposed through eight air holes 64 provided in the disk portion 38a of the movable body 38 as shown by arrows in the figure and is raised by the reciprocating vibration of the annular leaf spring 58. Flow through section 66. As a result, the cylindrical cylinder 22 and the stator core 32 are cooled satisfactorily due to the generation of airflow due to the reciprocating vibration of the annular leaf spring 58.
[0023]
Also, the gap 28 of the stator core 32 in which the electromagnetic coil 40 provided in the movable body 38 is arranged has one end opened and the presence of the insertion hole allows air to flow smoothly also in the gap 28. The temperature does not rise and the permanent magnet 34 does not demagnetize.
[0024]
Further, the oil supplied to the axial oil supply groove 62 provided on the outer peripheral surface of the cylindrical cylinder 22 is dropped on the outer peripheral surface of the piston 18 and passes through the gap of the annular leaf spring 58 and accumulates in an oil tank (not shown). Is supplied again to the oil supply groove 62 by an oil pump (not shown) and circulates in the above-described path. This cooling of the oil is also favorably performed by the above-mentioned air circulation.
[0025]
In the above-described embodiment, a compressor unit 24 for performing a compressing action is provided on one side of the motor unit 16, but the other embodiment shown in FIG. 3 is a two-cylinder linear compressor 10, and in this linear compressor 10, A piston 18 and a cylindrical cylinder 22 that receives the piston 18 and forms a compression chamber 20 are provided on both sides of the unit 16, that is, on both ends of the piston shaft 12. Also in this embodiment, the annular plate spring 58 described in the embodiment of FIG. 1 is arranged around the cylindrical cylinder 22, and an axial oil supply groove 62 is provided on the outer peripheral surface of the cylinder 22. Note that the compressor units 24 and 24 provided on both sides of the piston shaft 12 have the same configuration, and the corresponding portions are denoted by the same reference numerals and description thereof will be omitted. In this case, a common external cooling circuit (not shown) is connected to both compressor units 24 and 24.
[0026]
In the embodiment of FIG. 3, the compressor unit 24 arranged on the left side of the piston shaft 12 shows a compressed state (high pressure state), and the compressor unit 24 arranged on the right side of the piston shaft 12 shows a suction state (low pressure state). ).
[0027]
In the two-cylinder linear compressor 10 shown in FIG. 3, there is, for example, a third embodiment in which the right-side compressor unit 24 disposed on one side of the piston shaft 12 is eliminated and the annular leaf spring 58 is left as it is. . In this case, the air permeability is further improved as compared with the first embodiment shown in FIG.
[0028]
Further, the number of the annular leaf springs 58 used in each of the above-described embodiments can be appropriately selected according to, for example, a necessary spring constant, and may be one. However, in any case, the shape of the leaf spring 58 may be a shape other than “annular” in the embodiment.
[0029]
As described above, the linear compressor according to the present invention includes a motor unit having a movable portion that drives a piston shaft in the axial direction, a piston fixed to the piston shaft outside the motor unit in the axial direction, and fixed to the fixed portion. The motor includes a cylindrical cylinder that receives the piston and forms a compression chamber, and a plate spring that is disposed around the cylinder and has one end fixed to the movable portion and the other end fixed to the fixed portion. When the movable part and the piston shaft reciprocate by the driving of the unit, the leaf spring having one end fixed to the movable part also reciprocates, and the reciprocating vibration agitates the air around the cylindrical cylinder to generate an air flow. This air flow promotes heat radiation of the cylinder and the motor unit, and improves the compression efficiency of the linear compressor.
[Brief description of the drawings]
FIG. 1 is an illustrative view showing a main part of a linear compressor according to an embodiment of the present invention;
FIG. 2 is an illustrative view of a main part viewed from a compressor unit side in FIG. 1;
FIG. 3 is an illustrative view showing a cross section of a main part of a two-cylinder linear compressor showing another embodiment corresponding to FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Linear compressor 12 ... Piston shaft 14 ... Linear movable part 16 ... Motor unit 18 ... Piston 20 ... Compression chamber 22 ... Cylindrical cylinder 28 ... Air gap 32 ... Stator core 34 ... Permanent magnet 38 ... Movable body 40 ... Electromagnetic coil 58 ... annular leaf spring 62 ... oil supply groove

Claims (4)

A motor unit having a movable part that drives the piston shaft in the axial direction,
A piston fixed to the shaft outside the motor unit in the axial direction,
A cylinder fixed to a fixed portion and receiving the piston to form a compression chamber; and a leaf spring disposed around the cylinder and having one end fixed to the movable portion and the other end fixed to the fixed portion. , Linear compressor. The linear compressor according to claim 1, wherein an oil supply groove is provided in an axial direction on an outer peripheral surface of the cylinder. The linear compressor according to claim 1, wherein the plurality of leaf springs are provided with a gap in an axial direction. The linear compressor according to any one of claims 1 to 3, wherein the movable portion is provided with a ventilation hole.

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