JP4941699B2 - Outer movable linear actuator - Google Patents

Description

  The present invention relates to an outer movable linear actuator.

  A linear actuator that is composed of a stator and a mover and is driven linearly is widely used in motors for compressors and the like because it can be driven with reduced energy loss by using a spring together to resonate. Moreover, since the compressor using this linear actuator can exhibit excellent performance such as high efficiency, it is expected to be used for a refrigerator, a freezer or various air conditioners.

The linear actuator is classified into a movable coil type and a movable magnet type according to the arrangement of permanent magnets to be used, and the linear actuator of the present invention is a movable iron core type using permanent magnets. Various proposals have been made so far, and the magnetic circuit configuration of the outer movable actuator is disclosed in the embodiment of Japanese Patent Application Laid-Open No. 2003-339147, and the entire configuration of the inner movable actuator is disclosed in Japanese Patent Application Laid-Open No. 2004-343964. No. 2005-130646 discloses a mechanical structure of a magnet stop for an inner movable type.
JP 2003-339147 A JP 2004-343964 A JP 2005-130646 A

However, the conventional linear actuator has the following problems.
1) In the conventional linear actuator, the entire outer movable type configuration is not disclosed.
2) Further, in the case of the outer movable type, the mechanical magnet locking method used in the conventional inner movable type cannot be used. Therefore, fixing with only an adhesive is conceivable. However, there is a risk that the magnet may peel off in a high temperature environment or in a vibration environment due to reciprocating motion when used in a compressor, etc., and a mechanical magnet from the viewpoint of reliability. A stop mechanism is necessary. Furthermore, since the gap between the mover and the stator (the surface of the permanent magnet) is very small, it is necessary to devise the structure and assembly method.
3) Specifically, the outer periphery of the permanent magnet cannot be fixed with a band or the like. This is because the gap is narrow and there is a possibility of contact. Also, widening the gap is not possible because it leads to performance degradation. Furthermore, there is a possibility that an interfering part comes out during assembly and the stator cannot be inserted into the mover.

  This invention has been proposed in view of the above, has a function of mechanically holding a permanent magnet in an insulator constituting the stator, and improves reliability while maintaining a small gap between the mover and The object is to eliminate interference during assembly.

To achieve the above object, outer movable type linear actuator of the present invention, a shaft disposed through the center, the inner core disposed outside of said shaft, and disposed outside the inner core A permanent magnet magnetized in the radial direction of the shaft, a stator having a coil wound around the inner core, and a mover having an outer core disposed around the stator and split in the radial direction. And a leaf spring that elastically supports the stator and the mover coaxially concentrically and reciprocally, and the stator has a fixing mechanism for the permanent magnet, and the fixing mechanism is the inner core. The end of the permanent magnet that protrudes longer in the thrust direction, which is the axial direction of the shaft, is inserted and fixed in the thrust direction .

  In the present invention, the stator has a fixing mechanism for the permanent magnet.

  In the present invention, the permanent magnet fixing mechanism has a stopper function for regulating the stroke width of the mover.

  Since this invention consists of an above-described structure, there can exist an effect which is demonstrated below.

  In the present invention, an inner core, a permanent magnet disposed on the outer side thereof, a stator having a coil wound around the inner core, and an outer core that is disposed around the stator and can be divided into two in the radial direction. And a leaf spring that elastically supports the stator and the mover in a coaxial concentric manner so that they can reciprocate. Therefore, when assembling while maintaining a small gap between the mover and the permanent magnet An outer movable linear actuator that can eliminate the interference can be realized. Further, by dividing the outer core into two parts, it is possible to economically take materials as compared with a case where the outer core is integrated.

  In the present invention, since the stator has the fixing mechanism for the permanent magnet, the permanent magnet is mechanically and reliably fixed, and the reliability of the apparatus can be improved. Moreover, it is excellent in workability compared with the case of bonding.

  Further, in the present invention, the permanent magnet fixing mechanism has a stopper function for restricting the stroke width of the mover, so that the mover can be prevented from coming off. Further, since the reciprocating motion of the mover can be suppressed within the allowable amplitude of the leaf spring, the leaf spring can be prevented from being damaged.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating an embodiment. 1 is an exploded perspective view showing an example of an outer movable linear actuator according to the present invention, FIG. 2 is an overall perspective view of the outer movable linear actuator, FIG. 3 is a sectional view of the outer movable linear actuator, and FIG. It is a principal part expanded sectional view of a type | mold linear actuator. Here, the outer movable type linear actuator 10 is arranged around the stator 11, the mover 15 having the outer core 12, the spacer 13, and the cover 14, and the stator 11 and the mover 15 are coaxial. A leaf spring 16 that is concentric and elastically supported so as to reciprocate is provided.

  The mover 15 includes an outer core 12, a spacer 13, and a cover 14. The outer core 12 has a substantially cylindrical shape as a whole, and laminated steel plates laminated in the thrust direction are coupled so as to be split into two in the radial direction (see FIGS. 5 to 7). As shown in FIGS. 5 and 7, the outer core 12 is configured such that split elements 12 a that are axially symmetric with respect to the thrust axis can be joined at joints. One end of the joining portion is formed in the recessed groove 12c and the other end is formed in the projecting portion 12d, and can be fitted to each other.

  As the spacer 13 of the mover 15, laminated steel plates laminated in the thrust direction are used, and are joined so as to be divided into two in the radial direction (see FIGS. 5 and 8). In addition, the dividing elements 13a that are axially symmetric with respect to the thrust axis are configured to be able to be joined at the joints. One end of the joining portion is formed in the recessed groove 13c and the other end is formed in the projecting portion 13d, and can be fitted to each other. Further, the inner diameter is formed larger than the gap surface inner diameter 12f of the outer core 12 in order to reduce leakage of magnetic flux. The spacers 13 are disposed at both ends of the outer core 12 in the thrust direction, and serve as a reference for the attachment positions of the leaf springs 16 in the thrust direction.

  The outer core 12 and the spacer 13 are integrated by caulking or the like and configured as two elements 12a and 13a that can be divided in the radial direction. By comprising in this way, when attaching the needle | mover 15 to the stator 11, the interference with an outer diameter of an insulator and an outer core inner diameter can be avoided, and an assembly becomes possible. When the outer core is divided into two as shown in FIGS. 9 and 10, the dimension of the base material to be plated (the material is taken) is reduced from X2 to almost X1, rather than the integral annular body shown in FIG. Can be economical. The same applies to the spacer.

  The cover 14 has a substantially cylindrical shape, and the outer core 12, the spacer 13, and the leaf spring 16 are sandwiched and fixed from both ends in the thrust direction. As shown in FIG. 3, the cover 14 locks the spacer 13 and the leaf spring 16 at the step portion 14a, and holds the stator 11 and the movable element 15 in a coaxial concentric state. Moreover, it has the function of the decomposition | disassembly stop to the radial direction of the outer core 12 and the spacer 13 which were integrated. Further, it plays the role of the mass (weight) of the mover 15.

  11 is an overall perspective view of the stator, FIG. 12 is an exploded perspective view of the stator, FIG. 13 is a perspective view showing the insulator, FIG. 14 is a rear view showing the insulator, and FIG. 15 is a longitudinal sectional view showing the insulator. . The stator 11 has a permanent magnet 18 disposed outside the inner core 17 and an insulator 19 that fixes and holds the permanent magnet 18 and surrounds the inner core 17. It is comprised from the shaft 21 arrange | positioned.

  The inner core 17 is composed of laminated steel plates laminated in the thrust (reciprocating) direction. As shown in FIG. 12 and the like, the outer peripheral portion 17a for passing the magnetic flux to the outer core has an arc shape, and has a concave portion 17b for winding the coil and a through hole 17c for attaching the shaft. It is formed point-symmetrically from the center of.

  The permanent magnet 18 is magnetized in the radial direction and is an integral type having a surface NS pair in the thrust direction, and is formed longer in the thrust direction than the laminated thickness of the inner core 17. The permanent magnet 18 is curved with the same curvature as that of the outer peripheral portion 17 a of the inner core 17. It is not necessary to magnetize the portion that protrudes from the inner core 17 in the thrust direction.

  The insulator (bobbin) 19 is made of synthetic resin or the like and divided into two in the thrust direction, and the inner core 17 and the permanent magnet 18 are sandwiched and attached. The insulator 19 has a curved concave groove 19a for inserting a portion of the permanent magnet 18 that protrudes from the inner core 17. The concave groove 19 a is a fixing mechanism for the permanent magnet 18. By inserting the end portion of the permanent magnet 18 into the concave groove, it is possible to regulate the deviation of the permanent magnet in the radial direction and the thrust direction. For this reason, the flange part 22 in which the concave groove 19a of the insulator 19 is formed is formed larger in the radial direction than the outer diameter of the permanent magnet.

  The coil 20 is wound around the outer periphery of a recess 19 b formed in the insulator 19. This is for insulation from the inner core 17. The coil is connected so that a current flows in the same direction in the upper part and the lower part, and the mover can be reciprocated by switching the direction in which the current flows.

  As shown in FIGS. 3 to 11, the shaft 21 has a cylindrical shape, and is attached by penetrating the central portions of the inner core 17 and the insulator 19 in the thrust direction. Further, both end portions of the shaft 21 are used as a reference for the attachment position of the leaf spring 16 in the thrust direction. That is, the leaf spring 16 is used as a bearing that supports the stator 11 and the movable element 15 coaxially and concentrically. As is apparent from FIG. 1, the leaf spring 16 is sandwiched between the spring retainer 23 and the end portion of the shaft 21 and is fixed to the stator 11 side, the step 14a of the cover 14 and the spacer. 13 is composed of an outer circle 16b sandwiched between the end portions 13 and an arm portion 16c that connects the inner circle 16a and the outer circle 16b and elastically deforms the movable element 15 so as to reciprocate. The lead wire 24 is pulled out using the hollow portion of the shaft 21 and the spring retainer 23.

  FIG. 16 is an exploded perspective view showing a second embodiment of the stator. FIG. 17 is a longitudinal sectional view of the stator, and FIG. 18 is an explanatory view showing a procedure for attaching a permanent magnet in the second embodiment. In this embodiment, the stator 100 is wound around a bobbin 103 formed of an insulating material that is fixedly held to the permanent magnet 102 and the permanent magnet 102 disposed outside the inner core 101 and is attached to the inner core 101. A coil 106 to be rotated and a shaft 107 disposed so as to penetrate the central portion are formed. In the inner core 101, steel plates in which short arms and long arms are formed in a cross shape are stacked in the thrust direction, and the outer peripheral portion 101a of the long arm that passes magnetic flux to the outer core has an arc shape. The bobbin 103 has a mounting hole 105 that can be mounted on the long arm of the inner core 101, and a flange portion 104 that is formed to be substantially the same as the curvature of the permanent magnet 102 is formed. The bobbin 103 has a magnet mounting hole 108 that is wider than the mounting hole 105 and extends to the vicinity of the flange portion 104.

  The stator 100 thus configured is assembled as shown in FIG. First, after inserting one end of the permanent magnet 102 which is substantially equal to the length of the magnet mounting hole 108 of the bobbin 103 in the thrust direction, the other end is inserted. Next, the inner core 101 is mounted and pressed from below. The permanent magnet 102 is fixedly held by the magnet mounting hole 108 and the inner core 101. The upper and lower bobbins 103 or the bobbin and the inner core are fixed by a known fixing means.

  FIG. 19 is a longitudinal sectional view showing a third embodiment of the stator, and FIG. 20 is an exploded perspective view of the stator. The stator 300 has a permanent magnet 302 disposed outside the inner core 301, an end plate 303 disposed at both ends of the inner core 301 in the thrust direction, and an insulator 304 surrounding the inner core. And a coil 305 wound around the outer periphery of the insulator, a shaft 306 disposed through the center portion, and the like. The end plate 303 is formed in substantially the same shape as the inner core 301, but has an elongated hole 307 that is long in the radial direction and fixes the end of the permanent magnet 302. The elongated hole 307 has a shape in which the end of the curved permanent magnet 302 can be fitted. Further, the end plate 303 is made of a non-magnetic material in order to reduce leakage magnetic flux. It may be a magnetic material.

  The stator 300 configured as described above holds the permanent magnet 302 fixedly by the long holes 307 formed in the end plates 303 provided at both ends of the inner core 301 and surrounds the periphery by the insulator 304. Further, the coil 305 is wound from above the insulator 304.

  Each component configured as described above is assembled as follows. First, as shown in FIG. 1, leaf springs 16 are attached to both ends of the integrated stator 11 with spring retainers 23. Next, the integrated outer core 12 and spacer 13 are sandwiched from above and below in the radial direction and combined at the joint 12b. Finally, the outer core 12, the spacer 13, and the leaf spring 16 integrated by the cover 14 are sandwiched and assembled from the thrust direction. At this time, the coaxial concentric state of the stator 11 and the mover 15 is obtained. Further, the covers 14 at both ends are fixed with bolts 25.

  Further, as apparent from FIG. 4, since the outer diameter of the flange portion 22 of the insulator 19 is larger than the inner diameter of the outer core 12, the amount of movement of the mover 15 in the thrust direction is physically limited and has a stopper function. Therefore, it is possible to obtain the effect of preventing the mover 15 from coming off.

  In addition, although the above example demonstrated the case where a spacer was a laminated steel plate, a hollow tube may be sufficient. In that case, a means for coupling the outer core and the spacer is necessary. As the coupling means, a bolt or a coupling mechanism at the other end can be used. For example, an outer core and a spacer may be inserted and fixed in a hollow tube that regulates the outermost periphery. Furthermore, the spacer can be omitted if a leaf spring is press-fitted into the hollow tube.

FIG. 1 is an exploded perspective view showing an example of an outer movable linear actuator according to the present invention. FIG. 2 is an overall perspective view of the outer movable linear actuator. FIG. 3 is a sectional view of the outer movable linear actuator. FIG. 4 is an enlarged cross-sectional view of a main part of the outer movable linear actuator. FIG. 5 is a perspective view of the outer core and the spacer that are divided into two parts in the radial direction and integrated. FIG. 6 is a front view of FIG. FIG. 7 is a front view of the outer core. FIG. 8 is a front view of the spacer. FIG. 9 is an explanatory diagram showing material removal of the outer core of the present invention. FIG. 10 is an explanatory view showing material removal of the integrated outer core. FIG. 11 is an overall perspective view of the stator. FIG. 12 is an exploded perspective view of the stator. FIG. 13 is a perspective view showing an insulator. FIG. 14 is a rear view showing the insulator. FIG. 15 is a longitudinal sectional view showing the insulator. FIG. 16 is an exploded perspective view showing a second embodiment of the stator. FIG. 17 is a longitudinal sectional view of the stator. FIG. 18 is an explanatory diagram showing a procedure for attaching a permanent magnet in the second embodiment. FIG. 19 is a longitudinal sectional view showing a third embodiment of the stator. FIG. 20 is an exploded perspective view of the stator.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Outer movable type linear actuator 11 ... Stator 12 ... Outer core 13 ... Spacer 14 ... Cover 15 ... Movable element 16 ... Leaf spring 17 ... Inner core 18 ... Permanent magnet 19 ... Insulator 20 ... Coil 21 ... Shaft 22 ... Flange part 23 ... Spring retainer 24 ... Lead wire 25 ... Bolt

Claims (3)

A shaft penetrating through the central portion, an inner core disposed outside the shaft, a permanent magnet disposed outside the inner core and magnetized in the radial direction of the shaft , around the inner core a stator having a coil, a wound around,
A mover having an outer core disposed around the stator and capable of being divided into two in the radial direction;
A leaf spring that elastically supports the stator and the mover so as to be coaxial and concentric and reciprocally movable ;
The stator has a fixing mechanism for the permanent magnet,
The outer moving linear type , wherein the fixing mechanism is configured to insert and fix the end of the permanent magnet that protrudes longer in the thrust direction that is the axial direction of the shaft than the inner core in the thrust direction. Actuator. 2. The outer movable linear actuator according to claim 1, wherein the permanent magnet fixing mechanism has a stopper function for regulating a stroke width of the mover . 3. The outer movable linear according to claim 1 , wherein the stator includes an insulator having the fixing mechanism, and the insulator can be divided into two in a thrust direction or a radial direction of the shaft. Actuator.

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