CN112901442B

CN112901442B - DC linear compressor

Info

Publication number: CN112901442B
Application number: CN201911135179.0A
Authority: CN
Inventors: 俞国新; 许升; 陈庆; 李来福; 黄强; 刘洋; 贾勇勇; 宋斌; 虞朝丰; 董玮利; 吕守鹏
Original assignee: State Grid Jiangsu Electric Power Co Ltd; Qingdao Haier Smart Technology R&D Co Ltd; Haier Smart Home Co Ltd; Electric Power Research Institute of State Grid Jiangsu Electric Power Co Ltd
Current assignee: State Grid Jiangsu Electric Power Co Ltd; Qingdao Haier Smart Technology R&D Co Ltd; Haier Smart Home Co Ltd; Electric Power Research Institute of State Grid Jiangsu Electric Power Co Ltd
Priority date: 2019-11-19
Filing date: 2019-11-19
Publication date: 2022-10-28
Anticipated expiration: 2039-11-19
Also published as: CN112901442A

Abstract

The present application relates to a direct current linear compressor, comprising a mover having a piston and a stator having a cylinder, the mover being configured to reciprocate relative to the stator, the cylinder being provided with a direct current permanent magnet; the piston is provided with a direct current coil and is configured to reciprocate relative to the cylinder under the driving of the rotor; the direct current coil interacts with the direct current permanent magnet under the state of introducing direct current so as to enable the piston to suspend. When the rotor reciprocates relative to the stator, the direct-current linear compressor can drive the piston to reciprocate relative to the cylinder; because the cylinder is provided with the direct current permanent magnet, the piston is provided with the direct current coil, when the compressor is started, direct current is introduced into the direct current coil, a magnetic field generated by the direct current coil interacts with a magnetic field of the direct current permanent magnet, the piston can be suspended, and dry friction between the piston and the cylinder is avoided.

Description

DC linear compressor

Technical Field

The present application relates to the field of compressor technology, for example to direct current linear compressors.

Background

At present, the bottom of the compressor is provided with an oil pump, lubricating oil is provided for the piston through the oil pump, and frequent friction between the piston and the cylinder is reduced. However, the oil pump limits the setting height of the linear compressor, in order to further reduce the height of the linear compressor, the oil-free linear compressor is designed, compressed gas at the exhaust end leaks to support the piston to suspend, the setting of the oil pump is omitted, and the problem of reduction of heat exchange efficiency caused by the fact that oil enters a refrigerating system is solved. However, the oil-free compressor cannot perform dry friction for a long time, and the solution in the prior art can only perform special treatment on the contact surface of the piston or the cylinder, such as DlC spraying and the like, and adopts high-wear-resistant materials, which increases the cost and the process difficulty.

In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related art: when the exhaust pressure is not formed in the initial operation stage of the oil-free linear compressor, the piston cannot be suspended by leaked compressed air, dry friction is generated between the piston and the cylinder, and frequent dry friction operation causes rough friction surfaces and further abrasion, so that the compressor is damaged.

Disclosure of Invention

The following presents a simplified summary in order to provide a basic understanding of some aspects of the disclosed embodiments. This summary is not an extensive overview and is intended to neither identify key/critical elements nor delineate the scope of such embodiments, but is intended to be a prelude to the more detailed description that is presented later.

The embodiment of the disclosure provides a direct current linear compressor, which aims to solve the technical problem that dry friction is generated between a piston and a cylinder in the initial operation stage of the linear compressor.

In some embodiments, the dc linear compressor includes a mover having a piston and a stator having a cylinder, the mover being configured to reciprocate with respect to the stator, the cylinder being provided with a dc permanent magnet; the piston is provided with a direct current coil and is configured to reciprocate relative to the cylinder under the driving of the rotor; the direct current coil interacts with the direct current permanent magnet under the state of introducing direct current so as to enable the piston to suspend.

The direct current linear compressor provided by the embodiment of the disclosure can realize the following technical effects: when the rotor reciprocates relative to the stator, the piston can be driven to reciprocate relative to the cylinder; because the cylinder is provided with the direct current permanent magnet, the piston is provided with the direct current coil, when the compressor is started, direct current is introduced into the direct current coil, a magnetic field generated by the direct current coil interacts with a magnetic field of the direct current permanent magnet, the piston can be suspended, and dry friction between the piston and the cylinder is avoided.

The foregoing general description and the following description are exemplary and explanatory only and are not restrictive of the application.

Drawings

One or more embodiments are illustrated in the accompanying drawings, which correspond to the accompanying drawings and not in a limiting sense, in which elements having the same reference numeral designations represent like elements, and in which:

fig. 1 is a schematic structural view of a dc linear compressor provided in an embodiment of the present disclosure;

FIG. 2 is an enlarged view of portion A of FIG. 1;

fig. 3 is an axial view of the positional relationship of a dc coil and a dc permanent magnet provided by another disclosed embodiment.

Reference numerals are as follows:

1. a mover; 10. a mover permanent magnet; 2. a piston; 20. a direct current coil; 3. a stator; 4. a cylinder; 40. a direct current permanent magnet; 41. a stator coil; 5. a resonant spring; 6. an air discharge valve plate.

Detailed Description

So that the manner in which the features and elements of the disclosed embodiments can be understood in detail, a more particular description of the disclosed embodiments, briefly summarized above, may be had by reference to the embodiments, some of which are illustrated in the appended drawings. In the following description of the technology, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the disclosed embodiments. However, one or more embodiments may be practiced without these details. In other instances, well-known structures and devices may be shown in simplified form in order to simplify the drawing.

Fig. 1 is a schematic structural diagram of a dc linear compressor provided in an embodiment of the present disclosure. Fig. 2 is an enlarged view of a portion a of fig. 1. As shown in fig. 1 and 2, the disclosed embodiment provides a direct current linear compressor, comprising a mover 1 having a piston 2 and a stator 3 having a cylinder 4, the mover 1 being configured to reciprocate relative to the stator 3, the cylinder 4 being provided with a direct current permanent magnet 40; the piston 2 is provided with a direct current coil 20 and is configured to reciprocate relative to the cylinder 4 under the driving of the rotor 1; the dc coil 20 interacts with the dc permanent magnet 40 in the dc current supply state, so as to suspend the piston 2.

A stator 3 of a general linear compressor is provided with a stator coil 41, a mover 1 is provided with a mover permanent magnet 10, when the stator coil 41 of the compressor is supplied with power, an alternating electric field is generated in the stator coil 41, and an alternating magnetic field is formed by the principle of electromagnetic induction, and the alternating magnetic field interacts with the mover permanent magnet 10, so that the mover 1 connected with the mover permanent magnet 10 reciprocates relative to the stator 3, and also drives a piston 2 connected with the mover 1 to reciprocate in a cylinder 4, and a resonant spring 5 connected with the mover 1 does simple harmonic motion. In the reciprocating operation process of the piston 2, an air suction valve plate and an air discharge valve plate 6 of the compressor are oppositely opened and closed to form a compression process; the compressed gas is mostly discharged out of the compressor through the discharge cavity, and the smaller part of the compressed gas is discharged into a gap between the cylinder 4 and the piston 2 along a high-pressure gas leakage hole to form high-pressure gas, so that radial force is generated on the piston 2, and the piston 2 is suspended by the high-pressure gas. When the compressor is first powered on, since the compressed gas is not formed, the piston 2 cannot be suspended by the leaked compressed air, and dry friction is generated between the piston 2 and the cylinder 4.

Therefore, the direct current permanent magnet 40 is arranged in the cylinder 4, the direct current coil 20 is arranged on the piston 2, when the direct current linear compressor is electrified for the first time, the direct current coil 20 of the piston 2 is electrified, the direct current coil 20 generates an electromagnetic field, the electromagnetic field generated by the direct current coil 20 interacts with the electromagnetic field of the direct current permanent magnet 40, the piston 2 is suspended, and therefore dry friction between the piston 2 and the cylinder 4 is prevented. The electromagnetic field generated by the direct current coil 20 and the electromagnetic field of the direct current permanent magnet 40 may attract or repel each other, the direct current coil 20 and the direct current permanent magnet 40 form a suspension mechanism, and the suspension mechanism is symmetrically arranged along the axis of the piston 2, so that the acting force exerted on the piston 2 is symmetrical no matter the acting force between the piston 2 and the cylinder 4 is attracted or repelled, and the piston 2 can keep suspension.

The dc coil 20 is provided in the piston 2, the stator coil 41 is provided in the stator 3, the piston 2 is provided in the mover 1, and when the compressor is not operated, the stator coil 41 is not energized and does not generate a magnetic field, and a certain distance exists between the dc coil 20 and the stator coil 41, and when both the coils are energized, the both generate a magnetic field instantaneously, and the magnetic fields of the dc coil 20 and the stator coil 41 have a certain distance therebetween, and therefore, the magnetic fields of both have a small mutual influence. Moreover, the direct current coil 20 is energized when the compressor is started, and interacts with the direct current permanent magnet 40 to make the piston 2 move relative to the cylinder 4 in a suspension state for the first time, and after compressed gas is generated in the cylinder 4, the direct current coil 20 can be powered off, and the piston 2 is suspended by the compressed gas which is discharged to a gap between the cylinder 4 and the piston 2 along a high-pressure gas leakage hole instead of being suspended by magnetic force, so that the magnetic field generated by the direct current coil 20 in long reciprocating motion is prevented from influencing the magnetic field of the stator coil 41, and the stability of the reciprocating motion between the mover 1 and the stator 3 is further prevented. The dc coil 20 may be controlled by dc power, and after the compressor is started, the dc coil 20 is energized to suspend the piston 2 and compress gas near the cylinder 4, and then the dc coil 20 is deenergized.

In some embodiments, the dc permanent magnets 40 are disposed on the inner side wall of the cylinder 4. Piston 2 extends to the inside of cylinder 4 to relative cylinder 4 reciprocating motion sets up direct current permanent magnet 40 in the inside wall of cylinder 4, can be closer with piston 2's distance, and is more obvious to piston 2's effect. Alternatively, the inner side wall of the cylinder 4 is provided with a groove in which the direct current permanent magnet 40 is embedded. In this way, the dc permanent magnet 40 can be firmly attached to the cylinder 4. Optionally, the thickness of the dc permanent magnet 40 is less than or equal to the depth of the groove. In this way, the surface of the dc permanent magnet 40 faces the piston 2, and the dc permanent magnet 40 does not protrude out of the groove, preventing the piston 2 from being blocked from reciprocating.

In some embodiments, the dc permanent magnets 40 are arranged along the circumference of the cylinder 4, or symmetrically with respect to the axis of the cylinder 4.

The dc permanent magnets 40 are arranged circumferentially along the cylinder 4, i.e. the dc permanent magnets 40 extend annularly along the inner circumference of the cylinder 4. In this way, the magnetic field generated by the dc permanent magnet 40 is symmetrical, and the position setting corresponding to the dc coil 20 generates a balanced acting force on the piston 2, so that the piston 2 keeps floating, and avoids contacting the inner side wall of the cylinder 4 and generating dry friction. The dc permanent magnet 40 is symmetrically disposed with respect to the axis of the cylinder 4, for example, the dc permanent magnet 40 includes two sub-magnets, which are symmetrically disposed with respect to the axis of the cylinder 4, so as to generate a symmetric magnetic field, and generate a balanced acting force on the piston 2 to keep the piston 2 suspended in cooperation with the corresponding position of the dc coil 20.

In some embodiments, as shown in fig. 1, the stator 3 further has a stator coil 41, and the dc permanent magnets 40 are disposed in front of and/or behind the stator coil 41.

"front" means a side of the compressor close to the discharge valve plate 6, and "rear" means a side of the compressor close to the resonant spring 5. The stator 3 includes a base body provided with stator 3 slots that accommodate the stator coils 41, the front of the stator coils 41 being a portion of the base body located in front of the stator coils 41, and the rear of the stator coils 41 being a portion of the base body located behind the stator coils 41. The dc permanent magnets 40 are provided in front of and/or behind the stator coil 41, and the dc permanent magnets 40 provided in the cylinder 4 are provided in front of and/or behind the stator coil 41 as a base. The reciprocating motion between the stator 3 and the mover 1 of the compressor is realized by the interaction between the alternating magnetic field formed by the stator coil 41 and the mover permanent magnet 10 by utilizing the principle of electromagnetic induction, when the cylinder 4 is provided with the direct current permanent magnet 40, the direct current permanent magnet 40 has certain magnetism and may affect the magnetic field of the stator coil 41, therefore, the direct current permanent magnet 40 is arranged in front of and/or behind the stator coil 41, the positions of the direct current permanent magnet 40 and the stator coil 41 are staggered, and the influence of the magnetic field of the direct current permanent magnet 40 on the magnetic field generated by the stator coil 41 is avoided.

Optionally, the thickness of the direct current permanent magnet 40 is 1.5mm to 2.5mm. Since the wall thickness of the cylinder 4 is generally between 3mm and 5mm, the thickness of the direct current permanent magnet 40 is not too thick, and the mechanical strength of the wall of the cylinder 4 is not affected, and in this range, the direct current permanent magnet 40 can interact with the direct current coil 20 to suspend the piston 2.

In some embodiments, the dc coil 20 is disposed on an outer sidewall of the piston 2. The direct current coil 20 is on the lateral wall of piston 2, and the outside of the lateral wall of piston 2 is the inside wall of cylinder 4, and direct current coil 20 is closer to the direct current permanent magnet 40 of cylinder 4 like this, can promote the effect between direct current coil 20 and the direct current permanent magnet 40. Alternatively, the outer side wall of the piston 2 is provided with a caulking groove in which the direct current coil 20 is caulked. In this way, the dc coil 20 can be firmly attached to the piston 2.

In some embodiments, the dc coils 20 are disposed along the circumferential direction of the piston 2, or are disposed symmetrically with respect to the axial center of the piston 2. The direct current coil 20 is arranged along the circumference of the piston 2, i.e. the direct current coil 20 extends in a ring shape along the outer circumference of the piston 2. Therefore, the magnetic field generated by the direct current coil 20 is symmetrical, and the direct current permanent magnet 40 is arranged at a corresponding position, so that a balanced acting force can be generated on the piston 2, the piston 2 is kept suspended, and the contact with the inner side wall of the cylinder 4 and the dry friction are avoided. The position relationship between the dc coil 20 and the dc permanent magnet 40 is shown in fig. 3, and the dc coil 20 is symmetrically disposed with respect to the axis of the piston 2, so that the dc coil 20 generates a symmetric magnetic field when current is applied thereto, and the dc permanent magnet 40 is disposed at a corresponding position, so that the piston 2 is subject to a symmetric repulsive force or attractive force, and is subjected to a balanced force to achieve suspension.

In some embodiments, the number of the direct current permanent magnets 40 is plural, and is provided at intervals in the axial direction of the cylinder 4. The cylinder 4 sets up a plurality of direct current permanent magnet 40, and the piston 2 corresponds the direct current coil 20 that sets up the same quantity, and like this, the piston 2 carries out the interact at axial a plurality of regions and cylinder 4, makes the motion of piston 2 more steady, avoids because of the regional undersize of suspension, leads to piston 2 unbalance and cylinder 4 to bump. Optionally, the number of the dc permanent magnets 40 is two, the number of the dc coils 20 is two, and the distance between the two dc permanent magnets 40 is the same as the distance between the two sets of dc coils 20. In this way, the magnetic forces to which the piston 2 is subjected are equalized.

In some embodiments, the distance of the outer side of the dc permanent magnets 40 that are furthest apart is less than or equal to the axial length of the stator 3. Thus, after the compressor is started, the piston 2 moves towards the exhaust end for the first time, and when the positions of the direct current coil 20 and the direct current permanent magnet 40 are opposite, the piston 2 stops moving, so that the piston 2 is prevented from continuously moving towards the exhaust end and colliding with the exhaust valve plate 6. If the distance between the outer sides of the farthest direct current permanent magnets 40 is greater than the axial length of the stator 3, for example, the position of the direct current permanent magnet 40 at the rear of the cylinder 4 is unchanged, the position of the direct current permanent magnet 40 at the front of the cylinder 4 on the cylinder 4 exceeds the area covered by the stator 3, and the direct current permanent magnet 40 is closer to the exhaust valve plate 6, when the piston 2 moves toward the exhaust end, the position of the direct current permanent magnet 40 closer to the exhaust end needs to be moved to enable the direct current coil 20 to correspond to the position of the direct current permanent magnet 40, and thus the piston 2 easily impacts the exhaust valve plate 6. Therefore, by defining the distance of the outer side edge of the direct current permanent magnet 40 which is farthest away to be less than or equal to the axial length of the stator 3, the piston 2 is prevented from hitting the exhaust valve sheet 6 and causing damage.

In some embodiments, the number of dc coils 20 is multiple sets. The quantity of direct current coil 20 also can set up the multiunit, makes piston 2 carry out the interact in a plurality of regions of axial with the cylinder, makes piston 2's motion more steady, avoids because of the regional undersize of suspension, leads to piston 2 unbalance and cylinder to bump.

In some embodiments, the spacing between the plurality of sets of dc coils 20 is the same as the spacing between the plurality of dc permanent magnets 40. In this way, when the piston 2 moves to a position close to the exhaust end and stops, the positions of the dc coil 20 and the dc permanent magnet 40 can be matched, and the levitation state of the piston 2 is more stable.

The above description and the drawings sufficiently illustrate embodiments of the disclosure to enable those skilled in the art to practice them. Other embodiments may include structural and other changes. The examples merely typify possible variations. Individual components and functions are optional unless explicitly required, and the sequence of operations may vary. Portions and features of some embodiments may be included in or substituted for those of others. The scope of the embodiments of the present disclosure includes the full ambit of the claims, as well as all available equivalents of the claims. As used in this application, although the terms "first," "second," etc. may be used in this application to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element, unless the meaning of the description changes, so long as all occurrences of the "first element" are renamed consistently and all occurrences of the "second element" are renamed consistently. The first and second elements are both elements, but may not be the same element. Furthermore, the words used in the specification are words of description for example only and are not limiting upon the claims. As used in the description of the embodiments and the claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. Similarly, the term "and/or" as used in this application is meant to encompass any and all possible combinations of one or more of the associated listed. Furthermore, the terms "comprises" and/or "comprising," when used in this application, specify the presence of stated features, integers, and/or components, but do not preclude the presence or addition of one or more other features, integers, components, and/or groups thereof. Without further limitation, an element defined by the phrase "comprising a" \8230; "does not exclude the presence of additional like elements in a process, method or apparatus comprising the element. In this document, each embodiment may be described with emphasis on differences from other embodiments, and the same and similar parts between the respective embodiments may be referred to each other. For methods, products, etc. of the embodiment disclosures, reference may be made to the description of the method section for relevance if it corresponds to the method section of the embodiment disclosure.

The terms "front," "back," "inner," "outer," and the like, herein refer to an orientation or positional relationship based on that shown in the drawings for convenience in describing the present disclosure and simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus are not to be construed as limiting the present invention. In the description herein, unless otherwise specified and limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may include, for example, mechanical or electrical connections, and communication between two elements, and may include direct connection and indirect connection through intervening media, where the meaning of the terms is to be understood by those skilled in the art as appropriate. Herein, the term "plurality" means two or more, unless otherwise specified. Herein, the term "and/or" is an associative relationship describing objects, meaning that three relationships may exist. E.g., a and/or B, represents: a or B, or A and B.

Claims

1. A direct current linear compressor comprising a mover having a piston and a stator having a cylinder, said mover being configured to reciprocate relative to said stator, characterized in that said cylinder is provided with a direct current permanent magnet; the piston is provided with a direct current coil and is configured to reciprocate relative to the cylinder under the driving of the rotor; the direct current coil interacts with the direct current permanent magnet under the state of introducing direct current so as to enable the piston to suspend; the DC coil is configured to be energized upon start-up of the DC linear compressor, de-energized upon generation of compressed gas within the cylinder; the number of the direct current permanent magnets is multiple, and the direct current permanent magnets are arranged at intervals along the axial direction of the air cylinder; the distance of the outer side edge of the direct current permanent magnet which is farthest away is smaller than or equal to the axial length of the stator.

2. The direct current linear compressor of claim 1, wherein the direct current permanent magnet is disposed at an inner sidewall of the cylinder.

3. The direct current linear compressor according to claim 1, wherein the direct current permanent magnets are arranged along a circumferential direction of the cylinder.

4. A dc linear compressor as claimed in claim 3 wherein the dc permanent magnets are symmetrically disposed about the axis of the cylinder.

5. The direct current linear compressor according to claim 1, wherein the stator further has a stator coil, and the direct current permanent magnets are disposed in correspondence with a front and/or a rear of the stator coil.

6. A direct current linear compressor according to claim 1, characterized in that said direct current coil is provided on the outer side wall of said piston.

7. The direct current linear compressor according to claim 1, wherein the direct current coil is disposed along a circumferential direction of the piston.

8. A DC linear compressor as claimed in claim 7 wherein the DC coils are symmetrically disposed about the axial centre of the piston.

9. The direct current linear compressor according to claim 1, wherein the number of the direct current coils is a plurality of groups.

10. The dc linear compressor of claim 9, wherein a pitch between a plurality of sets of the dc coils is the same as a pitch between a plurality of the dc permanent magnets.