JP2001028871A - Linear actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a linear actuator whose space factor is increased and hose wire-wound resistance is lowered by a method wherein an annular stator which is provided with a coil and a permanent magnet is formed by connecting and fixing a plurality of core constituent members. SOLUTION: In a stator 13, a connected core is formed by connecting stator constituent members 13a, 13b, 13c, 13d, 13e, 13f, and 13g. Then, the stator constituent member 13a in the stator 13 is formed in such a way that T-shaped flat rolled magnetic steel sheets are laminated in its axial direction. In this state, a winding is wound in a concentrated manner around respective teeth, and a coil is obtained. In addition, magnet sets 40 to 47 which are provided with four poles in the axial direction are fixed to faces which face a moving element 12 in the respective parts. The stator constituent member 13a and the like in a plurality are connected, and the annular stator is formed. As a result, this linear actuator whose space factor is increased and whose wire-wound resistance is lowered can be formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear actuator.

[0002]

2. Description of the Related Art Conventional linear actuators include:
The one described in JP-T-8-505038 is known. This linear actuator has a cylinder-shaped mover 1 and a cylinder-shaped stator 2 that are arranged and configured in the concentric telescoping method shown in FIG. The stator 2 has a space 3 dimensioned for substantially frictionless axial movement with respect to the mover 1. The mover 1 interacts dynamically with the stator 2 and converts electrical energy into mechanical energy.

The mover 1 is dumbbell-shaped, and has a ring-shaped magnetic body usually arranged at two intervals. The stator 3
Usually each has eight sets of teeth. The teeth each have a plurality of radially spaced poles. 1
One tooth is defined by four poles. A plurality of permanent magnets 4 are installed in one tooth part in the axial direction.
The magnet switches its polarity radially.

[0004] The stator 2 further has eight sets of stator windings (not shown). Each stator winding is arranged in a winding slot and mounted on-axis on an associated set of stator poles P. Each stator winding is connected in series, and
A power supply (not shown) is connected to the end, and when energized, an electromagnetic force is generated to operate the linear actuator.

[0005]

However, in the above-mentioned conventional construction, the winding resistance is high because the winding ratio of the winding is not sufficient, and the width of the slot opening cannot be reduced due to the winding method. Since a sufficient amount of magnetic flux is not generated by the magnet, a large amount of current flows, which causes a problem that copper loss increases.

Here, the copper loss is as follows.

Wcu = Ia ² * Ra (1) where Ia represents an armature (or winding) current, and Ra represents a winding resistance.

The present invention solves such a conventional problem. By using a stator as a split core, the linearity is increased and the winding resistance is reduced. Further, by increasing the width of the tooth tip, a large number of permanent magnets can be used. Accordingly, it is an object of the present invention to provide a small, highly efficient and high-output linear actuator.

[0009]

According to the present invention, in order to solve the above-mentioned problems, in a linear actuator, a stator is divided into cores, thereby increasing the linearity and reducing the winding resistance. Further, by increasing the width of the tooth tip, many permanent magnets can be used.

[0010]

DETAILED DESCRIPTION OF THE INVENTION In order to solve the above problems, the present invention provides an annular stator having a coil portion and a permanent magnet;
A mover having a magnetic flux passage portion, and a linear actuator in which the mover reciprocates in the annular stator by an interaction between a magnetic flux generated in the coil portion and a magnetic flux generated in the permanent magnet, The annular stator is a linear actuator formed by connecting and fixing a plurality of core components. With this configuration, the occupation rate of the winding can be increased, so that the resistance value can be reduced. In addition, since a winding machine or the like can be used, the time required for winding can be greatly reduced.

Further, the width of the slot opening can be reduced. Since the amount of magnetic flux generated by the permanent magnet can be increased, the thrust generated by the same current is generated more effectively. With these, copper loss can be reduced. As a result, a high-efficiency, high-output linear actuator can be provided. Further, the same output can be downsized.

Also, by increasing the width of the tooth tip, the amount of magnetic flux generated by the permanent magnet can be increased. Thereby, more thrust can be used. Therefore, higher output can be achieved with higher efficiency, and further downsizing can be achieved with the same output.

[0013] Further, the permanent magnets constituting the respective poles are buried and arranged in the stator poles. This simplifies the installation of the permanent magnet, facilitates assembly, and provides a robust stator mechanism.

Further, any one of the permanent magnets described above is a plate magnet. As a result, the production of the permanent magnet is facilitated, and the cost can be reduced.

Further, by dividing the magnet set constituting each pole, more permanent magnets can be installed, so that the thrust generated by the same current can be increased. Further, the stator may be divided at a yoke portion. The stator may be divided at a tooth portion. Further, a ring is provided around the stator. This allows
Since the magnetic flux density can be reduced, iron loss is improved. Also, a robust stator mechanism is obtained.

[0016]

(Embodiment 1) Embodiment 1 will be described with reference to the drawings. The embodiment described below relates to a linear actuator having eight poles in the radial direction and four poles in the axial direction, but the number of poles is not limited.

FIG. 1 shows a linear actuator according to the first embodiment.
As shown in (1), a concentric telescoping method has a cylindrical movable element 12 and a cylindrical stator 13 arranged and configured in a concentric telescoping method, and performs correlated axial reciprocating movement.
Stator 13 has a space 14 dimensioned to provide substantially frictionless axial movement relative to mover 12. The mover 12 dynamically interacts with the stator 13 to convert electrical energy into mechanical energy.

When the movable element 12 is viewed in detail in FIG. 2, the movable element 12 is generally dumbbell-shaped, and is fixed to the shaft 15 with a gap between the magnetic portions 20 and 21. Magnetic parts 20, 21
Is formed by laminating a plurality of electromagnetic steel sheets to form a circular shape. By providing radial slits in the magnetic body portions 20 and 21, a magnetic flux path flowing through the magnetic body portions 20 and 21 is formed.

The stator 13 will be described in detail with reference to FIG. 1. The stator 13 includes stator constituent members 13a, 13b, 1
3c, 13d, 13e, 13f, and 13g are connected cores. The stator component member 13a is obtained by laminating T-shaped electromagnetic steel sheets in the axial direction as shown in FIG. Furthermore, a coil part (not shown) is obtained by concentrating winding around the teeth part in the state of the stator constituent member 13a. Further, the stator component 13a
The magnet set 40 is attached to the tip of the tooth portion by bonding, and a plurality of stator constituent members 13a and the like are connected to obtain an annular stator. At this time, the stator constituent members 13a, 1
The connecting portion 3b is connected by laser welding. The other stator components are similarly laser-welded to obtain the stator 13 connected in the annular direction.

The stator 13 has teeth arranged at radial intervals. Each tooth has a mover 12
The magnet sets 40 to 47 having four poles in the axial direction are fixed to the surface facing the. The magnet set 40 and the like have permanent magnets stacked in the axial direction, and are constituted by permanent magnets 40a to 40d as shown in FIG. 1B viewed from the axial direction of the stator.

That is, there are eight magnet sets in the stator 13 corresponding to the eight teeth portions. If the magnet sets have the same axial position, the magnetic poles of the main magnets adjacent in the radial direction are provided. Are different. That is, the magnet set 41 arranged on the side next to the magnet set 40 is
There is a different polarity to 2.

The linear actuator thus configured generates an electric magnetic flux by energizing the coil portion, and the mover vibrates in the axial direction by interaction with the magnetic flux generated by the permanent magnet. The operation at this time will be described. When the electric magnetic flux generated by energizing the coil portion passes through the teeth portion and flows in the direction of the mover 12, the magnet set 40 attached to the mover facing surface of the teeth portion is moved. Try to pass. At this time, since the magnetic flux directions of the permanent magnets of the magnet set 40 are different in the axial direction, the magnetic flux flowing through the teeth portion is strengthened at the portion where the permanent magnets 40a and 40c are going to pass, and passes through the permanent magnets 40b and 40d. Since the electric magnetic fluxes to be tried have different directions of the magnetic flux, they cancel each other out, and the magnetic flux generated from the teeth portion becomes very small. In other words, the magnetic poles of the teeth portion have a portion where the magnetic flux is strong in the axial direction and a portion where the magnetic flux is weak. The magnetic portions 20 and 21 of the mover 12 are attracted to the strength of the magnetic flux in the axial direction of the teeth portion, and the mover is moved. Move.

When the energization of the coil portion is switched in the opposite direction, the magnetic flux direction of the electric magnetic flux flowing through the teeth portion is reversed (from the mover to the outer periphery of the core). The parts that were strong (permanent magnets 40a, 40c) are weakened, and conversely, the parts where the magnetic flux was weak in the axial direction of the teeth before switching the energizing direction are strong. As described above, when the strength of the teeth changes, the portion to which the mover 12 is attracted also changes, so the mover 12 is attracted to the main magnets 40b and 40d of the teeth where the magnetic flux is strong. Thus, the movable element 12 vibrates by switching the energization.

Although the vibration of the linear actuator of the present embodiment has been described focusing on the teeth section 40, the movers of the teeth sections 41 to 47 are also vibrated by changing the energizing direction according to the same principle. However, the magnetic pole directions of the permanent magnets located at adjacent teeth and located at the same position in the axial direction are opposite to each other. This is because the magnetic flux passing through the mover 12 may form a magnetic flux loop between the adjacent teeth and the magnetic members 20 and 21.

[0025] As shown in FIG.
It can be divided axially into four stator sections 30a to 30d. The magnetic flux flowing through the teeth portion is
21 and the stator pole P, the magnetic flux changes from the minimum magnetic flux φmin to the maximum magnetic flux φmax.

Therefore, referring to FIG. 3, in two stator sections such as stator sections 30a and 30c, the permanent magnet (PM) bundle is positive (N polarity) as shown in FIG. 3 (a). On the other hand, in the other two stator sections such as the stator sections 30b and 30d, the permanent magnetic flux is negative (S polarity) as shown in FIG. The total magnetic flux for each pole P in one stator winding (not shown), as shown in FIG.
+2 (φmax−φmin) and −2 (φmax−φmin)
min).

Referring to FIG. 3 (a), a positive permanent magnetic flux curve 30ac illustrating the permanent magnetic flux φ in the stator poles as a function of the stroke length of the prime mover is shown. FIG. 3 (b)
Shows the negative curve 30bd of the permanent magnetic flux, while FIG.
Shows a permanent magnetic flux curve 30e illustrating the permanent magnetic flux φ induced in the coil associated with the pole P.

FIG. 3C shows that the PM bundle is zero in the middle of the stroke. Assuming that saturation is negligible, it can be assumed that flux line changes occur as a function of prime mover position. Therefore, assuming a harmonious movement, it is determined as follows.

X = １ ／ (ls × sinw1t) (1) Therefore, the rm of the total induced voltage when four coils are linked.
The s value is as follows:

Ea = 35.53f1 (φmax−φmin) Nc (2) where Nc is equal to the number of turns of each coil. F1 represents a frequency.

Next, the induced voltage and the resulting electromagnetic force will be examined in detail. The induced voltage is obtained by equation (2).
When the induced emf Ea and armature (or winding) current Ia are in phase, a maximum electromagnetic force is generated. That is, (Pem) max = EaIa (3) Therefore, the linear actuator is operated by being connected to the power supply Vs (not shown) and energizing the winding to generate an electromagnetic force.

Here, in the linear actuator according to the present embodiment, the stators 13 are respectively constituted by the stator constituent members 13a.
１３13h. This makes it possible to perform winding by a winding machine or the like for each of the stator cores such as the stator core constituent member 13a and the like, and the wire yield of the winding is greatly increased. Therefore, since the resistance value of the winding decreases, the copper loss can be reduced as is apparent from the above equation (1).

Further, since a winding machine can be used, the time required for winding can be greatly reduced. Furthermore, it is not necessary to wind up.

Further, by dividing, the width of the slot opening 16 can be reduced. Thus, the amount of permanent magnetic flux induced by the magnet set 40 and the like can be increased, and as a result, (φmax−φmin) increases. Therefore, as is apparent from the above equations (3) and (4), the thrust generated by the same current becomes larger. Further, the same output can be downsized.

The connecting surface between the stator constituent member 13a and the stator constituent member b shown in FIG. 1 is linear and connected by welding. However, the stator constituent member as shown in FIG. You may. That is, the connecting portion of the stator constituent member is shown in FIG.
The arc shape of the connecting portion 19a shown in FIG. 4A, the wedge shape of the connecting portion 19b shown in FIG. 4B, or the hook shape of the connecting portion 19c shown in FIG. Also, a combination of these shapes or another shape may be used.

By using the linear actuator of this embodiment for a compressor, a compact and highly efficient compressor can be obtained. Furthermore, by using this compressor, a compact and highly efficient air conditioner can be obtained. Furthermore, by using this compressor, a compact and highly efficient refrigerator can be obtained.

FIG. 5 is a sectional view showing a linear actuator according to a second embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description is omitted. In the second embodiment, by increasing the width of the tooth tip 18, more permanent magnets can be installed, so that the thrust generated by the same current can be increased.

(Embodiment 3) FIG. 6 is a sectional view of a stator constituting member 13a of a linear actuator according to Embodiment 3. The magnet set 40 constituting each pole may be installed in the stator pole. Such stator components are combined in a ring to form a stator. Such a linear actuator can obtain the same operation and effect as the first embodiment, and can easily install the permanent magnet, and can easily assemble the linear actuator.
A robust stator is obtained.

(Embodiment 4) FIG. 7 is a sectional view of a stator constituting member 13a of a linear actuator according to Embodiment 4. The magnet set 110 constituting each pole uses a flat plate magnet. The same operations and effects as those of the first embodiment in which the stator components are annularly combined to form the stator can be obtained, and the production of the permanent magnet can be simplified and the cost can be reduced.

(Embodiment 5) FIG. 8A is a sectional view of a stator component 13a showing a linear actuator according to Embodiment 5. FIG. Such stator components are combined in a ring to form a stator. Such a linear actuator can obtain the same operation and effects as those of the first, third, and fourth embodiments, and can install more permanent magnets by dividing and installing the magnet set 120. The thrust generated by the same current can be increased. In addition, as shown in FIG.
A plurality of permanent magnet embedding holes may be formed in a, and the permanent magnet 126 may be embedded in each of the plurality of embedding holes.

(Embodiment 6) FIG. 9 is a sectional view of a linear actuator according to Embodiment 6. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description is omitted. Such a stator is configured by connecting the stator constituent members 33a, 33b, 33c in a ring shape. The stator component 33a has two teeth portions on one stator. Providing a plurality of teeth portions on one stator component as described above facilitates assembly of the stator.

(Embodiment 7) FIG. 10 is a sectional view of a stator of a linear actuator according to Embodiment 7. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description is omitted. Example 7
Is characterized in that a ring 34 is provided around a stator constituted by a plurality of stator components 13a to 13g.
This allows the ring 34 to function as a back yoke and reduce the magnetic flux density. Thereby, copper loss and iron loss are improved. Furthermore, a robust stator mechanism is obtained.

(Eighth Embodiment) FIG. 11 is a sectional view of a stator of a linear actuator according to an eighth embodiment. This stator has teeth 213a, 2a inside ring-shaped core 219.
13b, 213c, 213d, 213e, 213f, 2
This is a stator obtained by connecting 13g and 213h. The teeth 213a and the like have a magnet set 240 at the tip.
To 247 are attached to each. A winding (not shown) is formed by concentrating the winding around the teeth portion 213 a and connected to the ring-shaped core portion 219. Although the connection laser welding is performed in FIG. 11, a caulking portion may be provided and assembled by press fitting.

(Embodiment 9) FIG. 12 is a view showing a linear actuator according to Embodiment 9. This linear actuator includes a cylindrical mover 301 and a stator located inside the mover 301. The stator comprises fixed components 302a, 302b, 302c, 302d, 3
02e, 301f, 302g, and 302h can be assembled by connecting them annularly. A magnet set 303 is attached to each of the stator constituent members, and a coil part 301 is obtained by winding a coil around the recess of the stator constituent member 301a. At this time, when the stator is obtained by connecting a plurality of stator components 301a provided with the coil portion 301a and the magnet set 303 in a ring shape, the stator components 301a and 301b are connected by laser welding.

[0045]

As is clear from the description of the above embodiment,
According to the first aspect of the present invention, by dividing the stator, the wire ratio of the winding can be increased, so that the resistance value can be reduced. Furthermore, slot open can be reduced. With these, copper loss can be reduced. As a result, a high-efficiency, high-output linear actuator can be provided. In addition, since a winding machine or the like can be used, the time required for winding can be greatly reduced.

Further, in the invention according to claim 2,
The same effect as described above is obtained, and the amount of magnetic flux generated by the permanent magnet can be increased by increasing the width of the tooth tip. Thereby, more thrust can be used. Further, a linear actuator having the same output as the conventional one can be configured with a small size and light weight.

Further, in the invention according to claim 3,
The same effects as described above can be obtained, and furthermore, the permanent magnets can be easily installed, easily assembled, and a robust stator mechanism can be obtained.

Further, in the invention according to claim 4,
The same effects as above can be obtained, and by using the flat permanent magnet end face, the production of the permanent magnet is facilitated and the cost can be reduced.

Further, in the invention according to claim 5,
The same effect as described above can be obtained, and more permanent magnets can be installed by dividing the magnet set constituting each pole, so that the thrust generated by the same current can be increased.

Further, in the invention according to claim 6,
The same effects as above can be obtained. Further, the same effect as described above can be obtained in the invention described in claim 7. Furthermore, in the invention according to claim 8, the same effect as described above can be obtained, and by providing a ring around the stator, the magnetic flux density can be reduced.
Iron loss is improved. Also, a robust stator mechanism is obtained. The tenth aspect of the present invention has a configuration in which the mover is disposed outside the stator, so that the surface area of the permanent magnet can be increased.

According to the eleventh aspect of the present invention,
By using the linear actuator of the above invention,
A compact and highly efficient compressor can be obtained.

Further, in the twelfth aspect of the present invention, a compact and highly efficient air conditioner can be obtained by using the compressor of the above invention. Further, in the invention according to the thirteenth aspect, by using the compressor of the above invention, a compact and highly efficient refrigerator can be obtained.

[Brief description of the drawings]

FIG. 1A is a sectional view of a linear actuator according to a first embodiment of the present invention. FIG. 1B is a view showing the permanent magnet set.

FIG. 2 is a perspective view of the mover.

FIG. 3 is an explanatory diagram of magnetic flux.

FIG. 4 is a view showing a connecting portion of the stator constituent members.

FIG. 5 is a sectional view of a linear actuator according to a second embodiment of the present invention.

FIG. 6 is a sectional view of a stator component according to a third embodiment of the present invention.

FIG. 7 is a sectional view of a stator constituent member according to a fourth embodiment of the present invention.

FIG. 8 is a sectional view of a stator constituent member according to a fifth embodiment of the present invention.

FIG. 9 is a sectional view of a linear actuator according to a sixth embodiment of the present invention.

FIG. 10 is a sectional view of a stator according to a seventh embodiment of the present invention.

FIG. 11 is a sectional view of a stator according to an eighth embodiment of the present invention.

FIG. 12A is a sectional view of a stator according to the eighth embodiment of the present invention, and FIG.
The figure which shows the same stator component

FIG. 13 is a sectional view showing a conventional linear actuator.

[Explanation of symbols]

 12 mover 13 stator 13a to 13h stator constituent members 14 space 15 axis

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiyuki Tamamura 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Shigeaki Fujiki 1006 Odaka Kadoma Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Shinichiro Kawano 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Yukihiro Okada 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Hiroshi Murakami Osaka Prefecture 1006 Kadoma Kadoma Matsushita Electric Industrial Co., Ltd. (72) Inventor Teruyuki Akazawa 1006 Kadoma City Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd.F term (reference) 5H002 AA03 AA07 AB01 AB03 AB04 AB06 AB08 AC02 AC06 AC08 AC09 AE07 AE08 5H622 AA03 CA02 CA05 CA10 CA14 CB03 CB05 PP10 PP11 PP19 5H633 BB07 BB11 GG02 GG04 GG09 GG1 1 GG12 GG13 HH02 HH04 HH05 HH06 HH09 HH11 HH13 HH15 HH18 HH20 HH22 HH24 HH27 5H641 BB05 BB14 BB19 GG02 GG04 GG08 HH02 HH08 HH10 HH12 HH13 HH14 HH16 HH20

Claims (13)

[Claims] An annular stator having a coil portion and a permanent magnet; and a mover having a magnetic flux passage portion, wherein an interaction between a magnetic flux generated by the coil portion and a magnetic flux generated by the permanent magnet is provided. A linear actuator in which the mover reciprocates in an annular stator, wherein the annular stator is configured by connecting and fixing a plurality of core components. 2. The linear actuator according to claim 1, wherein a tooth tip, which is a part of the annular stator, has a protrusion in a radial direction. 3. The stator according to claim 1, wherein the permanent magnet is embedded in the stator.
The linear actuator as described. 4. The linear actuator according to claim 1, wherein one of the permanent magnets is a plate magnet. 5. The linear actuator according to claim 1, wherein the permanent magnet constituting each pole is divided into a plurality in the radial direction of the stator. 6. The linear actuator according to claim 1, wherein the core component has a yoke portion and a teeth portion, and has an annular stator in which the yoke portions of the plurality of core components are combined. 7. The linear actuator according to claim 1, wherein the annular stator is configured by connecting and fixing an annular yoke constituent member and a teeth constituent member. 8. The linear actuator according to claim 1, wherein a fixing ring is provided around the annular stator. 9. A stator having a coil portion in which windings are concentratedly wound for each tooth portion is provided with a permanent magnet so that a magnetic flux of a permanent magnet flows through the tooth portion. The positive permanent magnet portion that flows in the positive direction of the teeth portion and the negative permanent magnet portion that flows in the negative direction are arranged in the axial direction. By changing the energizing direction of the coil portion, the positive permanent magnet portion is changed. Or, by weakening one of the magnetic poles of the negative permanent magnet portion, and strengthening the other magnetic pole, by switching the energizing direction of the coil portion, before switching the energizing direction, the magnetic pole that has been weakened by the electric magnetic flux is strong. The mover provided with a magnetic part is a linear actuator that reciprocates according to a change in magnetic flux of the teeth part, and the strengthened magnetic pole is weakened. A linear actuator consisting of connecting and fixing members. 10. An annular stator having a coil portion and a permanent magnet, and a mover having a magnetic flux passage so as to cover an outer periphery of the annular stator, wherein a magnetic flux generated in the coil portion and the permanent magnet are provided. Interaction with the magnetic flux generated by the
A linear actuator in which the mover reciprocates along an annular stator, wherein the annular stator includes a plurality of core components. 11. A compressor using the linear actuator according to claim 1. 12. An air conditioner using the linear actuator according to claim 1. 13. A refrigerator using the linear actuator according to claim 1.