JP7207084B2 - Moving coil type voice coil motor - Google Patents

Description

The present invention relates to a moving-coil voice coil motor having a small diameter and improved cooling efficiency.

A large moving-coil voice coil motor (hereinafter simply referred to as a "voice coil motor" or "VCM") used in a vibration exciter or the like is controlled using a large current. The eddy currents generated in the magnetic circuit used in the VCM also increase in proportion to the frequency. The generation of large eddy currents not only affects controllability, but also heats the magnetic circuit due to the heat generated by the eddy current, causing performance degradation of the magnetic circuit.Therefore, various cooling methods are used to cool the magnetic circuit. is being considered.

The heat (copper loss) generated by the eddy current generated in the magnetic circuit and the heat (copper loss) generated by the coil can be removed by air cooling by installing a fan in the magnetic circuit, or by water cooling by circulating cooling water inside the yoke. method is commonly used.

In the air-cooling method, countermeasures such as increasing the interval of the magnetic air gap where the coil is arranged are taken in order to secure the air volume and air path, but if the magnetic air gap is increased, the performance of the magnetic circuit deteriorates Resulting in. Therefore, countermeasures are taken such as making the magnetic gap as small as possible and using a fan with high static pressure performance in order to increase the flow velocity of the cooling air. However, a fan with high static pressure performance has problems such as noise generated by the fan and increased power consumption due to the use of a high-output motor. Furthermore, when using such a large fan, the installation location of the VCM is fixed to some extent, so there are problems such as not being able to easily change the layout in the factory, or the purpose of use being limited to some extent. .

JP 2018-26983 A (Patent Document 1) discloses a moving-coil type voice coil motor with improved air-cooling efficiency. a plurality of permanent magnets arranged in a cylindrical shape with a gap facing the surface; a cylindrical side yoke arranged around the outer periphery of the plurality of permanent magnets and fixing the plurality of permanent magnets; A bottom yoke magnetically coupling the axial ends of the yoke to the side yokes, and a coil axially movably disposed in the air gap, and cooling taken in from the top or bottom of the center yoke. Disclosed is a moving coil type voice coil motor characterized by having a through hole provided in the center yoke for direct blowing of air to the inner peripheral surface of the coil.

However, in response to the recent demand for higher output from large voice coil motors, the configuration described in Patent Document 1 is difficult to sufficiently prevent deterioration in performance due to temperature rise of the voice coil motor. Therefore, there is a demand for the development of a cooling mechanism capable of cooling with even higher efficiency even when a large current is applied.

Japanese Patent Application Laid-Open No. 3-173333 (Cited Document 2) discloses a magnetic pole arranged around an axis, a yoke arranged radially apart from the magnetic pole and having the axis as a central axis, and the A voice coil motor having a bobbin on which a coil is wound and which is displaceably guided parallel to the axis and spaced between the magnetic poles and the yoke, the bobbin having a coil wound therein, A yoke-cooled voice coil motor is disclosed in which a flow path for cooling fluid is provided in a region near the coil wound around the bobbin. Cited Document 2 describes that the provision of the cooling flow path inside the yoke allows the coil to be forcibly cooled, and the cooling efficiency is high.

However, in the voice coil motor disclosed in Cited Document 2, since the cooling flow path is provided only inside the yoke, it is possible to efficiently cool the magnetic poles (permanent magnets) that are spaced apart from the yoke. Can not. Therefore, it is not possible to sufficiently prevent the deterioration of the performance due to the temperature rise of the magnetic circuit. In addition, since the cooling flow path provided inside the yoke is provided so that the cooling fluid circulates from the central axis portion of the yoke to the outer peripheral portion, the yoke center portion, which does not need to be cooled, can be cooled. Therefore, there is room for improvement in terms of cooling efficiency.

Japanese Patent Application Laid-Open No. 2018-26983 JP-A-3-173333

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a moving-coil voice coil motor in which the cooling efficiency of the coil portion is enhanced and the deterioration of the performance of the magnetic circuit due to the heat generated by the coil is prevented.

As a result of intensive research in view of the above object, the present inventors have discovered a cylindrical center yoke, a plurality of permanent magnets arranged in a cylindrical shape with a gap facing the outer peripheral surface of the center yoke, and the gap. In a moving-coil voice coil motor having a coil arranged in a part, by providing a U-shaped permanent magnet side cooling pipe for flowing a coolant in the axial direction on the inner peripheral side of the plurality of permanent magnets, The inventors have found that the coils and permanent magnets can be cooled with high efficiency to prevent deterioration of the performance of the magnetic circuit, and have arrived at the present invention.

That is, the moving-coil voice coil motor of the present invention is
a cylindrical center yoke;
a plurality of permanent magnets arranged in a cylindrical shape with a gap facing the outer peripheral surface of the center yoke so as to apply a magnetic field in the radial direction of the center yoke;
a cylindrical side yoke connected to outer peripheral portions of the plurality of permanent magnets;
a bottom yoke that magnetically couples the center yoke to the side yoke at its axial lower end;
In a moving-coil voice coil motor having a coil arranged to be axially movable in the gap,
A U-shaped permanent magnet side cooling pipe for axially flowing a coolant is provided on the inner peripheral side of the plurality of permanent magnets.

It is preferable that a U-shaped center yoke side cooling pipe for axially flowing a coolant is provided on the outer peripheral side of the center yoke.

It is preferable that the permanent magnet side cooling pipe is provided at a position facing the center yoke side cooling pipe.

It is preferable that the center yoke-side cooling pipe and the permanent-magnet-side cooling pipe are provided at least three locations in the circumferential direction.

It is preferable that non-magnetic conductive rings are fixed to face the outer peripheral surface of the center yoke and the inner peripheral surfaces of the plurality of permanent magnets.

INDUSTRIAL APPLICABILITY The moving-coil voice coil motor of the present invention can cool the coils and permanent magnets with high efficiency and prevent deterioration of the performance of the magnetic circuit. Therefore, it is suitable for a moving-coil voice coil motor used in a vibration exciter or the like.

1 is a front view schematically showing an example of a moving-coil voice coil motor of the present invention; FIG. FIG. 1(a) is a cross-sectional view taken along line A-A of FIG. 1(a). FIG. 1B is a cross-sectional view taken along the line B-B of FIG. 1(b); FIG. 3 is an enlarged cross-sectional view showing a permanent magnet, a permanent-magnet-side cooling pipe, and a non-magnetic spacer extracted from FIG. 2(a). 2 is (a) a schematic diagram showing a permanent magnet side cooling pipe and its surroundings extracted from the moving-coil voice coil motor shown in FIG. 1, and (b) a perspective view schematically showing an extracted permanent magnet side cooling pipe. . FIG. 2 is a schematic diagram showing a state in which a pipe for water supply and drainage is connected to a cooling pipe on the permanent magnet side of the moving-coil voice coil motor shown in FIG. 1 via a connector; FIG. 4 is a front view schematically showing another example of the moving-coil voice coil motor of the present invention; 6 is (a) a schematic diagram showing the center yoke side cooling pipe and its surroundings extracted from the moving-coil voice coil motor shown in FIG. 5, and (b) a perspective view schematically showing the center yoke side cooling pipe extracted. FIG. . 6 is a schematic diagram showing a state in which pipes for water supply and drainage are connected to the permanent magnet side cooling pipe and the center yoke side cooling pipe of the moving-coil voice coil motor shown in FIG. 5 via connectors. FIG. FIG. 7(a) is a schematic diagram showing an enlarged portion D of FIG. 7(a). 7(a) is a schematic diagram showing paths of water supply pipes and water discharge pipes connected to the center yoke-side cooling pipe of FIG. 7(a). FIG. FIG. 8(a) is a cross-sectional view taken along line C-C of FIG. 8(a).

[1] Moving-coil Voice Coil Motor FIGS. 1(a) and 1(b) show an example of a moving-coil voice coil motor 1 of the present invention. FIG. 1(a) is a front view, and FIG. 1(b) is a sectional view taken along line AA of FIG. 1(a). A moving-coil voice coil motor 1 of the present invention includes a cylindrical center yoke 11 and a gap 20 that faces the outer peripheral surface of the center yoke 11 so as to apply a magnetic field in the radial direction of the center yoke 11. A plurality of permanent magnets 30 arranged in a cylindrical shape, a cylindrical side yoke 12 connected to the outer peripheral portion of the plurality of permanent magnets 30, and a magnetic coupling between the center yoke 11 and the side yoke 12 at the axial lower end thereof. a bottom yoke 13 that is physically coupled with a coil 40 arranged axially movably in the air gap 20; A U-shaped permanent magnet side cooling pipe 52 is provided.

In the moving-coil voice coil motor 1 shown in FIGS. 1(a) and 1(b), non-magnetic conductive rings 71 are further provided on the outer peripheral surface of the center yoke 11 and the inner peripheral surfaces of the plurality of permanent magnets 30, respectively. , 72 are arranged, a non-magnetic spacer 61 is arranged on the upper surfaces of the plurality of permanent magnets 30 and the side yoke 12, and a non-magnetic spacer 61 is arranged between the plurality of permanent magnets 30 and the bottom yoke 13. 62 are placed.

(1) Cooling pipe
(a) Permanent Magnet Side Cooling Pipe FIGS. 1(a), 1(b), 2(a) and 2(b) show an example of a moving coil type voice coil motor 1 of the present invention. FIG. 2(a) shows a BB cross-sectional view of FIG. 1(b), and FIG. 2(b) shows the permanent magnet 30, the permanent magnet side cooling pipe 52 and the nonmagnetic spacer 72 portion in FIG. 2(a). It is extracted and enlarged. This moving-coil voice coil motor 1 is an example in which eight U-shaped permanent-magnet-side cooling pipes 52 are provided at regular intervals in the circumferential direction. FIG. 3(a) shows the moving-coil voice coil motor shown in FIG. It is the figure seen from the side. Note that FIG. 3(a) omits the non-magnetic conductive rings 72 arranged on the inner peripheral surfaces of the plurality of permanent magnets 30. As shown in FIG. FIG. 3(b) is a perspective view showing only the permanent magnet side cooling pipe 52 extracted.

As shown in FIG. 3(b), the permanent magnet side cooling pipe 52 includes two vertical pipe portions 52a, 52a extending in the axial direction in parallel and one end of the two vertical pipe portions 52a, 52a. It consists of a U-shaped pipe portion 52b connecting the two ends (lower ends), and horizontal pipe portions 52c, 52c connecting to the other end (upper end) and extending radially outward. As shown in FIG. 3(a), the vertical tube portions 52a, 52a are arranged on the inner peripheral side of the permanent magnet 30, and the U-shaped tube portion 52b is preferably a non-magnetic magnet arranged below the permanent magnet 30. It is arranged so as to fold back in the spacer 62 . That is, it is preferable that the permanent magnet side cooling pipe 52 be arranged so as to cover and cool at least the permanent magnet 30 from the upper end to the lower end. The horizontal tube portions 52c, 52c are arranged above the non-magnetic spacer 61 arranged on the permanent magnet 30 and connected to the connector 82 provided on the non-magnetic spacer 61. As shown in FIG. Pipes for water supply and drainage can be connected to a solvent inlet 82a and a solvent outlet 82b provided in the connector 82 to allow coolant to flow through the permanent magnet side cooling pipe 52 (see FIG. 1(a)).

As shown in FIGS. 2(a) and 2(b), this moving-coil voice coil motor 1 has 16 trapezoidal permanent magnets 30a arranged cylindrically on the inner peripheral surface of the side yoke 12 when viewed in the axial direction. Eight permanent magnet side cooling pipes 52 are arranged on the inner peripheral side of the cylindrically arranged permanent magnets 30a so as to be in contact with every other permanent magnet 30a arranged in the circumferential direction. On the inner peripheral surface of the permanent magnet 30a on which the permanent magnet side cooling pipe 52 is arranged, a permanent magnet 30c having a rectangular shape in the axial direction is arranged so as to fill the space between the vertical tube portions 52a, 52a of the permanent magnet side cooling pipe 52. A permanent magnet 30b having a trapezoidal shape when viewed in the axial direction is arranged on the inner peripheral surface of the permanent magnet 30a where the permanent magnet side cooling pipe 52 is not arranged. Non-magnetic conductive rings 72 are provided on the inner peripheral sides (faces facing the center yoke 11) of these permanent magnet side cooling pipes 52 (vertical pipe portions 52a, 52a), permanent magnets 30c and 30b as necessary. can be placed.

When arranging the permanent magnet side cooling pipe 52 on the inner peripheral side of the permanent magnet 30, the divided permanent magnets 30a, 30b, 30c are combined and arranged as shown in FIGS. By doing so, it is not necessary to process the permanent magnets to form grooves or stepped portions, so that the efficiency of processing can be improved. In addition, a cylindrical body is produced by arranging the permanent magnet side cooling pipe 52 and the permanent magnets 30b and 30c around the polygonal cylindrical non-magnetic conductive ring 72, and this cylindrical body is attached to the inner peripheral surface of the side yoke 12. The moving-coil voice coil motor 1 can be easily assembled by inserting it inside the cylindrically arranged permanent magnet 30a. At this time, grooves for fitting the vertical pipe portions 52a, 52a of the permanent magnet side cooling pipe 52 are provided in advance around the non-magnetic conductive ring 72, so that the permanent magnet side cooling pipe 52 and the permanent magnets 30b are separated from each other. , 30c can be easily positioned. Of course, the trapezoidal permanent magnet may be formed by processing a groove or a stepped portion for fitting the permanent magnet side cooling pipe 52 .

Note that in the example shown here, the movable magnets 30a are composed of permanent magnets 30a that are trapezoidal in the axial direction divided into 16 in the circumferential direction, and eight permanent magnet side cooling pipes 52 that are arranged so as to be in contact with every other permanent magnet 30a. Although the coil-type voice coil motor 1 is shown, the number of permanent magnet divisions and the number of permanent magnet side cooling pipes arranged are not limited to these. For example, the number of divisions of the permanent magnets may be further increased (for example, 32 divisions), and the number of arranged permanent magnet side cooling pipes may be further increased (for example, 16 pieces). Also, the ratio between the number of divisions of the permanent magnet and the number of arrangement of the cooling pipes on the permanent magnet side may be freely changed. However, it is preferable to arrange the permanent-magnet-side cooling pipes at regular intervals in the circumferential direction. Further, the interval between the vertical tube portions 52a, 52a of the permanent magnet side cooling pipe 52 is preferably set according to the length of the side of the permanent magnet 30a with which the permanent magnet side cooling pipe 52 is in contact.

FIG. 4 shows a state in which pipes for supplying and draining coolant to and from the permanent magnet side cooling pipe 52 are connected to the solvent inlet 82a and the solvent outlet 82b of the connector 82. FIG. In this example, there are a water supply pipe 92a for supplying the refrigerant, seven connection pipes 92b for connecting the adjacent permanent magnet side cooling pipes 52, and a drainage pipe 92c for draining the refrigerant. Eight permanent magnet side cooling pipes 52 are connected so that the coolant flows in series. Here, the water supply pipe 92a is connected to the solvent inlet 82a of the first connector 82-1, and the connecting pipe 92b is connected to the solvent outlet 82b of the first connector 82-1 and the second connector 82-2. solvent inlet 82a, second connector 82-2 solvent outlet 82b and third connector 82-3 solvent inlet 82a, and so on, in order of seventh connector 82-7 solvent outlet 82b and Seven points up to the solvent inlet 82a of the eighth connector 82-8 are connected, and the drainage pipe 92c is connected to the solvent outlet 82b of the eighth connector 82-8.

The permanent-magnet-side cooling pipes 52 may be configured to flow coolant as independent systems, or may be configured to flow coolant by connecting several cooling pipes in series. Especially in the present invention, it is preferable that the permanent magnet side cooling pipes 52 are connected in series as shown in FIG. In the example shown in FIG. 4, all the permanent magnet side cooling pipes 52 are connected in series and are configured to be cooled in one system. may be configured to cool at For example, four permanent magnet side cooling pipes 52 are connected in series and cooled by the first system, and the remaining four permanent magnet side cooling pipes 52 are connected in series and are independent of the first system. It may be configured to cool as a second system. Further, when the number of permanent magnet side cooling pipes 52 is large, the number of cooling systems may be further increased.

(b) Center Yoke Side Cooling Pipe As shown in FIG. 5, the moving-coil voice coil motor 1 further includes a U-shaped center yoke side cooling pipe for axially flowing a coolant on the outer peripheral side of the center yoke 11. A tube 51 is preferably provided. FIG. 5 shows an example in which four center yoke-side cooling pipes 51 are provided in the circumferential direction of the center yoke 11, but the sizes of the center yoke-side cooling pipes 51 and connectors 81 are larger than those shown in FIG. The center yoke side cooling pipes 51 may be made smaller and provided at six or eight locations in the circumferential direction. Each center yoke side cooling pipe 51 is preferably provided at a position facing each permanent magnet side cooling pipe 52 with the gap 20 interposed therebetween.

FIG. 6(a) is a schematic diagram showing the center yoke side cooling pipe 51 and its surroundings (center yoke 11 and bottom yoke 13) of the moving-coil voice coil motor shown in FIG. . Note that FIG. 6(a) omits the non-magnetic conductive ring 71 arranged on the outer peripheral surface of the center yoke 11. As shown in FIG. FIG. 6(b) is a perspective view showing only the center yoke side cooling pipe 51 extracted.

As shown in FIG. 6(b), the center yoke-side cooling pipe 51 includes two vertical pipe portions 51a, 51a extending in the axial direction in parallel and one end of each of the two vertical pipe portions 51a, 51a. It consists of a U-shaped tube portion 51b connecting the two ends (lower ends), and horizontal tube portions 51c, 51c connecting to the other end (upper end) and extending toward the center of the center yoke 11 above the center yoke 11. As shown in FIG. 6(a), the vertical tube portions 51a and 51a and the U-shaped tube portion 51b of the center yoke side cooling pipe 51 are preferably embedded in grooves provided on the outer peripheral surface of the center yoke 11. As shown in FIG. preferable. A non-magnetic conductive ring 71 can be arranged on the outer peripheral side (the surface facing the permanent magnet 30) of these center yoke side cooling pipes 51 (vertical pipe portions 51a, 51a) as necessary. The horizontal tube portions 51c, 51c are connected to a connector 81 provided on the center yoke 11. As shown in FIG. As will be described later, the refrigerant can flow through the center yoke side cooling pipe 51 by connecting pipes for water supply and drainage to the solvent inlet 81a and the solvent outlet 81b provided in the connector 81. FIG.

FIGS. 7(a) and 7(b) show a state in which the water supply/drainage piping for supplying and discharging the refrigerant to and from the center yoke side cooling pipe 51 is connected to the solvent inlet 81a and the solvent outlet 81b of the connector 81. FIG. It is a schematic diagram showing. In this example, there are a water supply pipe 91a for supplying the refrigerant, three connection pipes 91b for connecting the adjacent center yoke side cooling pipes 51, and a drainage pipe 91c for draining the refrigerant. The four center yoke side cooling pipes 51 are connected so that the refrigerant flows in series. Here, the water supply pipe 91a is connected to the solvent inlet 81a of the first connector 81-1, and the connection pipe 91b is connected to the solvent outlet 81b of the first connector 81-1 and the second connector 81-2. solvent inlet 81a, solvent outlet 81b of second connector 81-2 and solvent inlet 81a of third connector 81-3, and solvent outlet 81b of third connector 81-3 and fourth connector Three locations of the solvent inlet 81a of the connector 81-4 are connected, and the drain pipe 91c is connected to the solvent outlet 81b of the fourth connector 81-4.

FIGS. 8(a) and 8(b) show paths of a water supply pipe 91a and a water discharge pipe 91c connected to the center yoke side cooling pipe 51 shown in FIG. 7(a). For simplicity, FIGS. 8(a) and 8(b) show the horizontal pipe portion 51c of the center yoke side cooling pipe 51 arranged on the upper surface of the center yoke 11, the connector 81, the connecting pipe 91b, and the Horizontal pipe portion 52c of permanent magnet side cooling pipe 52 arranged on the upper surface of magnetic spacer 61, connector 82, water supply pipe 92a, connection pipe 92b, and drainage pipe 92c are omitted.

Here, as shown in FIG. 7(b), notches 11b and 13b are formed in the through holes 11a and 13a passing through the centers of the center yoke 11 and the bottom yoke 13, and the water supply pipe 91a and As shown in FIGS. 8(a) and 8(b), the drainage pipe 91c includes a vertical pipe portion 91a-1 extending to the lower end of the bottom yoke 13 through the notches 11b and 13b, and a vertical pipe portion 91a-1. and horizontal pipe portions 91a-2 and 91c-2 connected to the vertical pipe portions 91a-1 and 91c-1, respectively, and extending to the outer edge portion of the bottom yoke 13. is preferred. A connector 83 is preferably further provided at a portion where the horizontal tube portion 91a-2 and the horizontal tube portion 91c-2 extend from the outer edge of the bottom yoke 13. As shown in FIG.

The center yoke-side cooling pipes 51 may be configured to flow the coolant as independent systems, or may be configured to flow the coolant by connecting several cooling pipes in series. Especially in the present invention, it is preferable that the center yoke side cooling pipes 51 are connected in series as shown in FIG. 7(a). In the example shown in FIG. 7(a), all the center yoke side cooling pipes 51 are connected in series and are configured to be cooled by one system. It may be configured to cool in a plurality of systems.

(c) Configuration of Cooling Pipes The moving-coil voice coil motor 1 shown in FIG. 5 is provided with four center-yoke-side cooling pipes 51 in the circumferential direction and eight permanent-magnet-side cooling pipes 52 in the circumferential direction. However, the number of center yoke-side cooling pipes 51 and permanent magnet-side cooling pipes 52 is not limited to these configurations, and may be changed depending on the size of the moving-coil voice coil motor 1, the cooling efficiency, the shape of the permanent magnets, and the like. may be configured. In order to cool the moving-coil voice coil motor 1 efficiently, it is preferable to provide at least three center-yoke-side cooling pipes 51 and permanent-magnet-side cooling pipes 52 in the circumferential direction.

The cross-sectional shape of the cooling pipe is not particularly limited, but when embedded in a groove provided in a permanent magnet, yoke or non-magnetic spacer, the cooling efficiency is increased by increasing the contact area with the permanent magnet, yoke or non-magnetic spacer. Therefore, it is preferable to have the same shape as the groove. A quadrilateral shape is particularly preferred in terms of readiness for processing. In order to increase the cooling efficiency, it is preferable to fill the gap between the groove provided in the permanent magnet, yoke or non-magnetic spacer and the cooling pipe with a filler having a high thermal conductivity.

(2) Permanent magnet The permanent magnet 30 is made of, for example, a sintered ferrite magnet, and is a ring-shaped magnet that applies a magnetic field in the radial direction as a whole when a plurality of circumferentially divided permanent magnets 30 are arranged in a cylindrical shape. configure. The permanent magnet 30 is magnetized, for example, so that the side facing the center yoke 11 has an N pole and the side yoke 12 side has an S pole.

(3) Non-magnetic conductive ring As shown in FIGS. 1(a) and 1(b), the moving-coil voice coil motor of the present invention comprises an outer peripheral surface of a center yoke 11 and a plurality of permanent magnets opposed thereto. Nonmagnetic conductive rings 71 and 72 are preferably secured to the inner peripheral surface of 30, respectively. These non-magnetic conductive rings 71 and 72 have the effect of reducing eddy currents and are provided as required. Nonmagnetic conductive rings 71 and 72 are preferably made of, for example, copper plates.

(4) Other Configurations The center yoke 11, the side yokes 12, and the bottom yoke 13 are made of a ferromagnetic material such as soft iron or steel, and the coil 40 faces the inner peripheral surface of the permanent magnet 30. It is wound in a direction interlinking magnetic flux with the outer peripheral surface of the center yoke 11 . When alternating current is supplied to the coil 40, the coil 40 vibrates up and down in the magnetic field between the inner peripheral surface of the permanent magnet 30 and the outer peripheral surface of the center yoke 11 facing it. By placing a device under test (not shown) on a movable table (not shown) or the like connected to the coil 40, a vibration test of the device under test can be performed.

1・・・Moving coil type voice coil motor
11・・・Center yoke
11a ... through hole
11b...Notch
12・・・Side yoke
13a ... through hole
13b...Notch
13・・・Bottom yoke
20... Gap
30 Permanent magnet
30a: Permanent magnet
30b Permanent magnet
30c・・・Permanent magnet
40 Coil
51・・・Center yoke side cooling pipe
51a・・・Vertical pipe part
51b・・・U-tube part
51c・・・Horizontal tube
52・・・Permanent magnet side cooling pipe
52a・・・Vertical pipe part
52b・・・U-tube part
52c・・・horizontal tube
61・・・Non-magnetic spacer
62・・・Non-magnetic spacer
71,72・・・Non-magnetic conductive ring
81,82,83・・・Connectors
81-1 to 81-4・・・1st to 4th connectors
82-1 to 82-8・・・1st to 8th connectors
81a, 82a・・・Solvent inlet
81b,82b・・・Solvent outlet
91a, 92a・・・Piping for water supply
91a-1・・・Vertical tube part
91a-2・・・horizontal tube
91b, 92b・・・Piping for connection
91c, 92c・・・Drain piping

Claims (5)

a cylindrical center yoke;
a plurality of permanent magnets arranged in a cylindrical shape with a gap facing the outer peripheral surface of the center yoke so as to apply a magnetic field in the radial direction of the center yoke;
a cylindrical side yoke connected to outer peripheral portions of the plurality of permanent magnets;
a bottom yoke that magnetically couples the center yoke to the side yoke at its axial lower end;
In a moving-coil voice coil motor having a coil arranged to be axially movable in the gap,
A moving-coil voice coil motor, wherein a U-shaped permanent-magnet-side cooling pipe for axially flowing a coolant is provided on the inner peripheral side of the plurality of permanent magnets. In the moving-coil voice coil motor according to claim 1,
A moving coil type voice coil motor, wherein a U-shaped center yoke side cooling pipe for axially flowing a coolant is provided on the outer peripheral side of the center yoke. In the moving-coil voice coil motor according to claim 2,
A moving coil type voice coil motor, wherein the permanent magnet side cooling pipe is provided at a position facing the center yoke side cooling pipe. In the moving-coil voice coil motor according to claim 2 or 3,
A moving-coil voice coil motor, wherein the center yoke-side cooling pipe and the permanent-magnet-side cooling pipe are provided in at least three locations in a circumferential direction. In the moving-coil voice coil motor according to any one of claims 1 to 4,
A moving-coil voice coil motor, wherein a nonmagnetic conductive ring is fixed to face the outer peripheral surface of the center yoke and the inner peripheral surfaces of the plurality of permanent magnets.

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