JP2020068625A - Cylindrical linear motor - Google Patents

Abstract

To provide a cylindrical linear motor that is easy to wire and easy to assemble.SOLUTION: A cylindrical linear motor 1 according to the present invention includes a rod 11, an armature 2 having a cylindrical shape and having a core 3 mounted on the outer periphery of the rod 11 and a winding 5 mounted on a slot 4 provided on the outer periphery of the core 3, a cover 17 that covers the outer periphery of the rod 11 and forms an annular gap G between the cover and the rod 11, a field 6 in which the rod 11, the cover 17, and the armature 2 are cylindrically inserted inward so as to be movable in the axial direction, and N poles and S poles are alternately arranged in the axial direction, and a lead wire L that is housed in the gap G and has one end led out of the cover 17 and the other end connected to the winding 5.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cylindrical linear motor.

  The cylindrical linear motor is, for example, a field magnet having a plurality of permanent magnets accommodated in the inner circumference of an outer cylinder so that S poles and N poles are alternately arranged in the axial direction, and is movable to the inner circumference of the field magnet. There is an armature having a cylindrical rod to be inserted into and a three-phase winding of U-phase, V-phase and W-phase mounted on the outer periphery of the rod.

  In the cylindrical linear motor configured as described above, the windings are connected in series in the same phase, and one end of each phase winding is connected to the lead wire. Then, the three lead wires respectively connected to the respective phase windings are drawn out above the armature through the gap between the armature and the rod and connected to an external power source (see, for example, Patent Document 1). ).

JP, 2013-29159, A

  The conventional cylindrical linear motor has a problem that the wiring work is very difficult and the assembly is troublesome because the lead wire is pulled out to the outside through the narrow rod.

  Therefore, an object of the present invention is to provide a tubular linear motor that is easy to wire and can be easily assembled.

  In order to achieve the above object, a cylindrical linear motor of the present invention includes a rod, a cylindrical core mounted on the outer periphery of the rod, and a winding mounted on a slot provided on the outer periphery of the core. An armature that has, a cover that covers the outer periphery of the rod and forms an annular gap between the rod, and a cylindrical rod, the rod and the cover and the armature are inserted inwardly so as to be movable in the axial direction. A field magnet in which N poles and S poles are alternately arranged in the direction, and a lead wire which is housed in the air gap and has one end led out of the cover and the other end connected to the winding wire. In the cylindrical linear motor configured as described above, the lead wire for each phase and the winding wire for each phase can be connected outside the rod before the cover is attached to the rod, and the cover can be removed after the connection work is completed. Can be attached to the rod.

  In addition, the cylindrical linear motor has windings including a U-phase winding, a V-phase winding and a W-phase winding, and a lead wire connected to the U-phase winding and the V-phase winding. Three lead-out holes each having a V-phase lead wire and a W-phase lead wire connected to the W-phase winding, and the cover individually and independently leading out the U-phase lead wire, the V-phase lead wire, and the W-phase lead wire, respectively. May be provided. In the cylindrical linear motor configured as described above, the U-phase lead wire, the V-phase lead wire, and the W-phase lead wire are led out to the outside independently from the corresponding lead-out holes. The lead wire and the W-phase lead wire may be separated. Therefore, according to the cylindrical linear motor configured as described above, good insulation between phases of the windings of each phase can be realized.

  Further, the cylindrical linear motor is housed in a space and has a U-phase connecting portion connecting the U-phase winding and the U-phase lead wire and a V-phase connecting portion connecting the V-phase winding and the V-phase lead wire. And a ring-shaped or arc-shaped relay stand having a W-phase connection section that connects the W-phase winding and the W-phase lead wire, and the U-phase connection section, the V-phase connection section, and the W-phase connection section are mutually relay stations. It may be provided at positions spaced apart from each other in the circumferential direction. According to the cylindrical linear motor configured in this way, the windings of each phase and the lead wires of each phase can be arranged in positions separated from each other in the air gap, so that good insulation between the phases of the windings of each phase can be achieved. Can be realized.

  Further, the tubular linear motor of the present embodiment includes a cover holding member provided on the outer periphery of the rod and on the proximal end side of the armature, and the cover has an annular cover end provided on the outer periphery of the rod, and a cylinder. And a cover tube having one end fitted to the outer circumference of the cover end and the other end fitted to an elastic body mounted on the outer circumference of the cover holding member. According to the tubular linear motor configured as described above, eccentricity and inclination are allowed with respect to the rod, so that even if the rod bends, the cover is not strongly pressed against the head cap and can be smoothly expanded and contracted.

  Furthermore, the tubular linear motor of the present embodiment includes a plurality of non-magnetic inner tubes provided on the inner circumference of the field and a plurality of slidable inner tubes provided on both axial sides of the core of the rod. Of the slider, the slider arranged on the most proximal end side of the rod has a small outer diameter portion on the proximal end side of the rod and a small diameter portion on which the elastic body is mounted. The part may be a cover holding member. According to the tubular linear motor configured as described above, it is not necessary to provide a cover holding member separately, the number of parts is reduced, the cover can be attached to the rod, and the eccentricity of the armature with respect to the field is prevented. it can.

  Further, in the cylindrical linear motor, the cover cylinder may include a ventilation hole that communicates the gap with the inside of the inner tube. According to the tubular linear motor configured as described above, since the chamber on the left side of the slider in the inner tube that is expanded / contracted by the expansion / contraction operation of the cylindrical linear motor is always communicated with the gap, the pressure fluctuation in the chamber Is alleviated and the cylindrical linear motor can be expanded and contracted smoothly.

  Further, in the tubular linear motor, the elastic body may be a ring that seals between the cover holding member and the cover tube, and water or dust can be prevented from entering the inner tube or the armature.

  According to the cylindrical linear motor of the present invention, wiring work is easy and can be easily assembled.

It is a longitudinal cross-sectional view of a cylindrical linear motor in one embodiment. It is a sectional view of a cover cylinder of a cylindrical linear motor in one embodiment. It is a perspective view of the relay stand of the cylindrical linear motor in one embodiment.

  The present invention will be described below based on the embodiments shown in the drawings. As shown in FIG. 1, a tubular linear motor 1 according to one embodiment includes a rod 11, a core 3 that is tubular and is attached to the outer periphery of the rod 11, and a slot 4 that is provided on the outer periphery of the core 3. An armature 2 having a winding 5 attached thereto, a cover 17 that covers the outer circumference of the rod 11 and forms an annular gap G between the rod 11 and the rod 11, which is cylindrical and inward. The cover 17 and the armature 2 are movably inserted in the axial direction, and the field 6 in which the N poles and the S poles are alternately arranged in the axial direction, and the field G is housed in the gap G and one end thereof is led out of the cover 17. And a lead wire L whose other end is connected to the winding 5.

  Hereinafter, each part of the tubular linear motor 1 will be described in detail. The armature 2 includes a core 3 and a winding wire 5. The core 3 is configured to include a cylindrical core body 3a and a plurality of teeth 3b that are annular and are provided on the outer periphery of the core body 3a at intervals in the axial direction, and serve as a mover.

  As described above, the core 3 has a tubular shape, and as shown in FIG. 1, is provided with ten teeth 3b arranged on the outer periphery of the core body 3a at equal intervals in the axial direction. A slot 4 which is an air gap in which the winding 5 is mounted is formed therebetween. Further, each tooth 3b has an annular shape, and except for the teeth 3b arranged at both ends of the core 3, each tooth 3b has an isosceles trapezoid shape in which the width of the outer peripheral end is narrower than the width of the inner peripheral end in the axial direction, Side surfaces on both sides in the axial direction are tapered surfaces that are inclined at an equal angle with respect to the outer peripheral end. The teeth 3b at the ends have a cross-sectional shape in which the teeth 3b other than the teeth 3b at the ends are cut in half in a plane orthogonal to the axis of the core 3. In this way, the cross-sectional shape of each tooth 3b is a trapezoid whose width at the outer peripheral edge is narrower than that at the inner peripheral edge.

  In addition, in the present embodiment, a total of nine slots 4 that are voids are provided between the teeth 3b, 3b adjacent to each other in FIG. A winding 5 is wound around and attached to the slot 4. The winding 5 is composed of a three-phase winding including a U-phase winding 5u, a V-phase winding 5v, and a W-phase winding 5w. In the nine slots 4, W-phase winding 5w, W-phase winding 5w, W-phase winding 5w and V-phase winding 5v, V-phase winding 5v, V-phase winding 5v are arranged in order from the left side in FIG. , V phase winding 5v and U phase winding 5u, U phase winding 5u, U phase winding 5u, U phase winding 5u and W phase winding 5w are mounted. The U-phase winding 5u, the V-phase winding 5v, and the W-phase winding 5w are connected in series for each phase, and one end of each phase winding 5u, 5v, 5w is connected, and The other end is pulled out to the left of the core 3 in FIG.

  The lead wire L is composed of three lead wires Lu, Lv, Lw, which are a U-phase lead wire Lu, a V-phase lead wire Lv, and a W-phase lead wire Lw, and each lead wire Lu, Lv, Lw is It is connected to the other ends of the corresponding phase windings 5u, 5v, 5w via a relay stand 27.

  The armature 2 is mounted on the outer circumference of the tip of the rod 11 which is an output shaft and is made of a non-magnetic material. The rod 11 includes a tubular first rod 20 and a tubular second rod 21 to which the core 3 is attached on the outer periphery and which is screwed onto the inner periphery of the first rod 20.

  The first rod 20 is cylindrical and has a rod body 22 having screw portions 22a and 22b on the outer periphery at the left end in FIG. 1 and the inner periphery at the right end in FIG. 1, and a bracket 23a for attaching the cylindrical linear motor 1 to a device. The rod body 22 is provided with an end cap 23 that is screwed to a screw portion 22a at the left end in FIG. 1 to close the left end of the rod body 22.

  An annular slider 25 is fitted around the right end of the rod body 22 in FIG. The slider 25 has a sliding contact portion 25a that is in sliding contact with the inner periphery of an inner tube 9 described later, and an outer diameter provided on the proximal end side of the rod 11 that is the left side in FIG. 1 of the sliding contact portion 25a. A small-diameter portion 25b having a smaller diameter than 25a, an annular groove 25c provided along the circumferential direction on the outer circumference of the small-diameter portion 25b, and a flange 25d provided on the inner circumference at the right end in FIG. A rubber seal ring 26 as an elastic body is attached to the annular groove 25c of the slider 25. Further, the inner diameter of the flange 25d is equal to or larger than the inner diameter of the rod body 22 and smaller than or equal to the outer diameter of the rod body 22, and when the slider 25 is fitted into the rod body 22, the flange 25d is the right end of the rod body 22 in FIG. Abut the surface.

  The second rod 21 includes a cylindrical core holding cylinder 21a on which the core 3 is mounted, and an annular slider 21b provided on the outer circumference of the tip that is the right end in FIG. 1 of the core holding cylinder 21a. Further, a screw portion 21c is provided on the outer periphery of the base end that is the left end in FIG. 1 of the core holding cylinder 21a, and the inner diameter of the core holding cylinder 21a on the base end side is larger than the inner diameter of other parts. A large diameter portion 21d is provided. Then, the base end of the core holding cylinder 21a is inserted into the inner periphery of the rod body 22 of the first rod 20 at the right end in FIG. 1 and the screw portion 21c is screwed into the screw portion 22b. The rod 21 is connected. Thus, in the present embodiment, the rod 11 is configured by the first rod 20 and the second rod 21 and has a tubular shape.

  The core 3 is fitted and mounted on the outer periphery of the core holding cylinder 21a of the second rod 21. Since the outer diameter of the core holding cylinder 21a is smaller than the outer diameter of the rod body 22 of the first rod 20, the second rod 21 having the armature 2 mounted thereon is attached to the first rod 20 having the slider 25 mounted thereon. When connected in the manner described above, the armature 2 and the slider 25 are sandwiched and fixed by the right end of the first rod 20 in FIG. 1 and the slider 21b of the second rod 21. When the armature 2 is mounted on the rod 11 in this way, the core 3 is fixed to the rod 11 in a state of being sandwiched between the slider 21b and the slider 25. In addition, in the present embodiment, the armature 2 is configured to have only the single core 3, but it may be configured to have a plurality of cores 3 in order to reduce the cogging thrust.

  Subsequently, the cover 17 covers the outer circumference of the rod 11 to form a gap G. Specifically, the cover 17 is tubular with an annular cover end 18 provided on the outer circumference of the rod 11, one end of which is fitted to the outer circumference of the cover end 18, and the other end of which is the small diameter portion 25 b of the slider 25. And a cover cylinder 19 fitted to a seal ring 26 as an elastic body mounted on the outer periphery of the.

  The cover end 18 is fixed to the outer periphery of the rod 11 near the base end thereof, and is provided on the cylindrical nut portion 18a screwed to the screw portion 22a of the rod body 22 and the left end of the nut portion 18a in FIG. And a flange 18b that is formed.

  The cover cylinder 19 has a tubular shape and is provided with a fitting portion 19a having a thicker wall and a smaller inner diameter than the other portion at the left end in FIG. 1, which is one end, and as shown in FIG. On the other hand, there are provided three lead-out holes 19b which are provided at intervals in the circumferential direction and penetrate the fitting portion 19a. In addition, the three lead-out holes 19b are provided at equal intervals in the circumferential direction with respect to the cover cylinder 19 in the present embodiment. Further, the cover cylinder 19 is provided with a vent hole 19c which is always in communication with the inner tube 9 at the right end in FIG.

  The fitting portion 19a of the cover cylinder 19 is fitted into the nut portion 18a of the cover end 18. Specifically, the fitting portion 19a is fitted to the nut portion 18a by loose fitting, and a slight inclination of the cover cylinder 19 with respect to the cover end 18 and looseness in the radial direction are allowed. Further, the right end in FIG. 1, which is the other end of the cover cylinder 19, is fitted to the outer circumference of the seal ring 26 mounted on the outer circumference of the small diameter portion 25 b of the slider 25. The cover cylinder 19 is sandwiched between the cover end 18 and the slider 25, and its axial movement is restricted. However, the cover cylinder 19 is loosely fitted to the cover end 18 and is fitted into the seal ring 26, which is an elastic body. 11, eccentricity and inclination are allowed. Further, the small diameter portion 25b of the slider 25 has a role of holding the cover cylinder 19 when the cover cylinder 19 is attached to the rod 11, and constitutes a cover holding member. The elastic body is not limited to the seal ring 26 as long as it has elasticity and can allow the eccentricity of the cover cylinder 19 with respect to the small diameter portion (cover holding member) 25b. The cover cylinder 19 and the small diameter portion (cover holding member) 25b are not limited to the seal ring 26. If it is not necessary to seal the space between them, it is not necessary to form an annular shape surrounding the entire circumference of the small diameter portion (cover holding member) 25b.

  The relay stand 27 is mounted on the outer circumference of the rod 11 between the cover end 18 and the slider 25, and is housed in the gap G between the cover 17 and the rod 11. In the present embodiment, the relay stand 27 is annular, and includes a U-phase connecting portion 27u, a V-phase connecting portion 27v, and a W-phase connecting portion 27w, as shown in FIG. The U-phase connecting portion 27u, the V-phase connecting portion 27v, and the W-phase connecting portion 27w are provided on the relay stand 27 at intervals in the circumferential direction. In the present embodiment, U-phase connecting portion 27u, V-phase connecting portion 27v and W-phase connecting portion 27w are provided at equal intervals in the circumferential direction with respect to relay stand 27.

  As shown in FIGS. 1 and 3, an eyeglass terminal 5u1 is provided at one end of the U-phase winding 5u drawn out from the slot 4 of the core 3, and an eyeglass terminal is also provided at one end of the U-phase lead wire Lu of the other party. A terminal Lu1 is provided. Then, the U-phase winding 5u and the U-phase lead wire are connected to each other by screwing the screws 27a inserted into the spectacle terminals 5u1 and Lu1 stacked on the U-phase connecting portion 27u of the relay stand 27 to the U-phase connecting portion 27u. Lu is connected. Similar to the U-phase winding 5u and the U-phase lead wire Lu, eyeglass terminals are provided at one end of the V-phase winding 5v and the W-phase winding 5w and at one end of the V-phase lead wire Lv and the W-phase lead wire Lw. ing. The V-phase winding 5v and the V-phase lead wire Lv, and the W-phase winding 5v and the W-phase lead wire Lw are connected to the V-phase connection of the relay stand 27 in the same manner as the U-phase winding 5u and the U-phase lead wire Lu. It is fixedly connected to the portion 27v and the W-phase connecting portion 27w.

  The lead wires Lu, Lv, Lw of each phase can be connected to the windings 5u, 5v, 5w of each phase outside the rod 11, and after the connection work is completed, the cover 17 is attached to the rod 11. The lead wire L may be housed in the cover 17. Therefore, since the wiring work of the tubular linear motor 1 of the present embodiment can be performed outside the rod 11, the wiring work becomes very simple, and the tubular linear motor 1 can be easily assembled.

  Further, the relay stand 27 is housed in the gap G between the cover 17 and the rod 11, the relay stand 27 is annular, and the U-phase connecting the U-phase winding 5u and the U-phase lead wire Lu The connection portion 27u, the V-phase connection portion 27v that connects the V-phase winding 5v and the V-phase lead wire Lv, and the W-phase connection portion 27w that connects the W-phase winding 5w and the W-phase lead wire Lw are relayed. Since they are provided at positions separated from each other in the circumferential direction of the table 27, good insulation between the phases of the windings 5u, 5v, 5w of each phase can be realized. If the relay stand 27 is annular, if the U-phase connecting portion 27u, the V-phase connecting portion 27v, and the W-phase connecting portion 27w are arranged at equal intervals on the circumference, the connecting portions 27u, 27v, and 27w will be the closest to each other. Although they can be separated from each other, which is advantageous in terms of insulation, they may be arcuate.

  The U-phase lead wire Lu, the V-phase lead wire Lv, and the W-phase lead wire Lw are housed in the gap G between the rod 11 and the cover 17, and the other ends thereof are individually and independently. It is led out to the outside through each lead-out hole 19b and connected to an external drive circuit (not shown). Therefore, the cylindrical linear motor 1 is driven by receiving current supply from the drive circuit to the windings 5u, 5v, 5w of each phase via the lead wires Lu, Lv, Lw of each phase.

  In this way, the U-phase lead wire Lu, the V-phase lead wire Lv, and the W-phase lead wire Lw are individually and independently led out of the cover 17 from the three lead-out holes 19b provided in the cover 17. Also in this respect, good insulation between the phases of the windings 5u, 5v, 5w of each phase can be realized.

  Subsequently, in the present embodiment, the field magnet 6 is configured to include a cylindrical laminated magnet body M and a back yoke 8 formed of a cylindrical magnetic body mounted on the outer periphery of the laminated magnet body M. It is accommodated in an annular gap between the outer tube 7 formed of a cylindrical non-magnetic material and the cylindrical inner tube 9 of a non-magnetic material inserted into the outer tube 7. Further, an annular head cap 15 through which the rod 11 is inserted inside is attached to the open end of the outer tube 7, and the inner tube 9 is provided integrally with the head cap 15.

  The laminated magnet body M has a plurality of annular main magnetic poles 10a that are axially alternately stacked and inserted into the inner periphery of the tubular back yoke 8 and that are permanent magnets 10a that are a plurality of annular auxiliary magnetic poles. And is configured. In FIG. 1, the triangular marks on the permanent magnet 10a of the main magnetic pole and the permanent magnet 10b of the auxiliary magnetic pole indicate the magnetizing direction, and the magnetizing direction of the permanent magnet 10a of the main magnetic pole is the radial direction. The magnetizing direction of the permanent magnet 10b of the auxiliary magnetic pole is the axial direction. The permanent magnets 10a of the main magnetic poles and the permanent magnets 10b of the auxiliary magnetic poles are arranged in a Halbach array, and on the inner peripheral side of the field magnet 6, the S poles and the N poles are arranged alternately in the axial direction. .

  Further, in the tubular linear motor 1 of the present embodiment, the axial length of the permanent magnet 10a of the main magnetic pole is longer than the axial length of the permanent magnet 10b of the auxiliary magnetic pole. In this way, by increasing the axial length of the permanent magnet 10a of the main magnetic pole, the magnetic resistance between the permanent magnet 10a of the main magnetic pole and the core 3 can be reduced and the magnetic field acting on the core 3 can be increased. The thrust of the cylindrical linear motor 1 can be improved.

  Further, in the tubular linear motor 1 of the present embodiment, the back yoke 8 is provided on the outer circumference of the permanent magnets 10a and 10b. When the back yoke 8 is provided, a magnetic path having a low magnetic resistance can be secured, so that an increase in magnetic resistance due to a reduction in the axial length of the permanent magnet 10b of the auxiliary pole can be suppressed. Therefore, when the axial length of the permanent magnet 10a of the main magnetic pole is made longer than the axial length of the permanent magnet 10b of the auxiliary magnetic pole, and the cylindrical back yoke 8 is provided on the outer circumference of the permanent magnets 10a and 10b, the cylindrical linear motor is obtained. The thrust of 1 can be greatly improved. The thickness of the back yoke 8 may be set to a thickness suitable for suppressing an increase in external magnetic resistance of the permanent magnet 10a of the main pole.

  The armature 2 is inserted on the inner peripheral side of the field magnet 6 so as to be movable in the axial direction, and the field magnet 6 causes a magnetic field to act on the core 3. The magnetic field 6 may be applied to the movable range of the core 3 so that the installation range of the permanent magnets 10a and 10b may be determined according to the movable range of the core 3. Therefore, it is not necessary to install the permanent magnets 10a and 10b in the annular gap between the outer tube 7 and the tubular portion 9b in a region that cannot face the core 3. The length of the back yoke 8 is equal to the length in which the permanent magnets 10a and 10b are laminated, and the permanent magnets 10a and 10b do not act on the magnetic field outside the stroke range of the core 3 to reduce the thrust. Is considered as.

  Further, the outer tube 7 has a bottom portion 7a provided with a reduced diameter on the right end side in FIG. 1, and is provided with a bracket 7b at the right end of the bottom portion 7a that allows the tubular linear motor 1 to be attached to a device. .

  Further, as shown in FIG. 1, the head cap 15 and the inner tube 9 are made of a non-magnetic material and integrally molded, and the inner tube 9 projects rightward from the right end of the head cap 15 in FIG. . The field magnet 6 is attached to the outer circumference of the inner tube 9 so as to be immovable in the axial direction. Specifically, an annular spacer 40, a field 6, and an annular stopper 41 are sequentially fitted to the outer circumference of the inner tube 9 from the left in FIG. 1, and when the head cap 15 is screwed to the outer tube 7. The spacer 40, the field 6 and the stopper 41 are sandwiched between the head cap 15 and the bottom portion 7 a of the outer tube 7, and the field 6 is fixed to the outer circumference of the inner tube 9. The back yoke 8 mounted on the outer circumference of the field magnet 6 is constrained by the field magnet 6 by the magnetic force of the field magnet 6 and therefore does not move inside the outer tube 7.

  An annular seal member 28, which is in sliding contact with the outer circumference of the cover 17 that covers the outer circumference of the first rod 20, is provided on the inner circumference of the head cap 15 to prevent dust and water from entering the cylindrical linear motor 1. Intrusion is prevented.

  Then, the rod 11 having the armature 2 mounted therein is axially movably inserted into the inner tube 9, and the sliders 21b and 25 are slidably contacted with the inner circumference of the inner tube 9 so as to move in the axial direction of the armature 2. You will be guided to move.

  The inner tube 9 forms a gap between the outer circumference of the core 3 and the inner circumference of each of the permanent magnets 10a and 10b, and plays a role of guiding the axial movement of the core 3 in cooperation with the sliders 21b and 25. There is. In addition, in the present embodiment, the armature 2 is configured to have only a single core 3. However, when the armature 2 has a plurality of cores 3, not only the axial ends of the armature 2 but also the core 3, A slider that slidably contacts the inner circumference of the inner tube 9 may be provided between the three.

  Further, a guide rod 16 is attached to the inner circumference of the bottom portion 7a of the outer tube 7. The guide rod 16 includes a base end portion 16a fixed to the inner circumference of the bottom portion 7a and a guide portion 16b extending from the base end portion 16a toward the rod 11 and slidably inserted into the rod 11. Even when the cylindrical linear motor 1 expands and contracts, it is always in sliding contact with the inner circumference of the rod 11. More specifically, the guide portion 16b of the guide rod 16 is slidably inserted to the tip side of the inner diameter large diameter portion 21d of the second rod 21.

  As described above, in the tubular linear motor 1 according to the present embodiment, the guide rod 16 is in sliding contact with the inner circumference of the rod 11, and the sliders 21b and 25 are in sliding contact with the inner tube 9. It can move smoothly in the axial direction without being eccentric to the field magnet 6.

  Further, in the tubular linear motor 1 configured as described above, the inner tube 9 that guides the axial movement of the armature 2 and prevents the eccentricity of the armature 2 with respect to the field 6 is integrated with the head cap 15. Therefore, the inner tube 9 and the head cap 15 are less likely to be distorted, and the sliders 21b and 25 can smoothly slide on the inner circumference of the inner tube 9 and can be smoothly expanded and contracted.

  Further, the cylindrical linear motor 1 of the present embodiment houses the stroke sensor S in the rod 11. In the present embodiment, the stroke sensor S is a linear variable differential transformer, and although not shown in detail, a cylindrical sensor body 30 containing a primary coil and two secondary coils, and the sensor body 30. The probe 32 is movably inserted in the axial direction, and has a probe 32 having a sensor core 31 as a detected element at its tip. The linear variable differential transformer detects the position of the sensor core 31 from the difference between the induced voltages of the two secondary coils that are induced when the AC voltage is applied to the primary coil.

  When the sensor body 30 is inserted into the first rod 20 in advance, the slider 25 is fitted to the end portion of the first rod 20, and the second rod 21 is screwed to the first rod 20, the sensor body 30 becomes The stepped portion formed at the right end of the large inner diameter portion 21 d of the second rod 21 and the end cap 23 of the first rod 20 are sandwiched and fixed in the first rod 20. As described above, the sensor body 30 is housed in the first rod 20 in which the armature 2 is not mounted on the outer circumference, and is housed in a range that does not face the armature 2 in the radial direction of the rod 11.

  The probe 32 of the stroke sensor S is rod-shaped and is attached to the tip of the guide portion 16 b of the guide rod 16. Therefore, the sensor core 31 as the detected element is fixedly connected to the field 6 via the probe 32, the guide rod 16 and the outer tube 7. As described above, the probe 32 is provided with the sensor core 31 at the tip, and the tip side is inserted into the sensor body 30. Therefore, as the armature 2 moves in the axial direction with respect to the field 6, the probe 32 moves in the axial direction relative to the sensor body 30, and the sensor core 31 moves in the sensor body 30. .

  Since the guide rod 16 holding the probe 32 is slidably inserted into the rod 11 accommodating the sensor main body 30, radial eccentricity of the sensor core 31 with respect to the sensor main body 30 is prevented. The wiring for energizing the primary coil of the sensor main body 30 and the wiring connected to the secondary coil are drawn out from a hole provided in the end cap 23 and connected to a controller (not shown) although not shown.

  Then, a controller (not shown) detects the position of the rod 11 with respect to the magnetic field 6 by the stroke sensor S, grasps the electrical angle of the core 3 with respect to the magnetic field 6, switches the energization phase, and performs PWM control to control each winding 5. Is controlled to control the thrust of the cylindrical linear motor 1 and the moving direction of the armature 2. The control method in the controller described above is an example, and the present invention is not limited to this. Further, when an external force that relatively displaces the armature 2 and the field 6 in the axial direction acts, a thrust force that suppresses the relative displacement by energizing the winding 5 or by an induced electromotive force generated in the winding 5. Can be generated to cause the cylindrical linear motor 1 to damp vibrations and movements of the device due to the external force, and energy regeneration to generate electric power from the external force is also possible.

  As described above, the tubular linear motor 1 of the present invention includes the rod 11, the core 3 that is tubular and is attached to the outer periphery of the rod 11, and the winding that is attached to the slot 4 provided on the outer periphery of the core 3. An armature 2 having a wire 5; a cover 17 that covers the outer circumference of the rod 11 and forms an annular gap G between the rod 11; and a cylindrical rod 11, the cover 17 and the armature inwardly. A field 6 in which 2 is movably inserted in the axial direction and N poles and S poles are alternately arranged in the axial direction, and one end is led out of the cover 17 and the other end is housed in the gap G. And a lead wire L connected to the winding 5. In the cylindrical linear motor 1 configured as described above, the lead wires Lu, Lv, Lw of each phase and the windings 5u, 5v, 5w of each phase are provided outside the rod 11 before the cover 17 is attached to the rod 11. It is possible to perform connection work with and to attach the cover 17 to the rod 11 after the connection work is completed. Therefore, according to the tubular linear motor 1 of the present embodiment, the wiring work can be performed outside the rod 11, so that the wiring work is very simple and the tubular linear motor 1 is easily assembled.

  Further, in the cylindrical linear motor 1 of the present embodiment, the winding 5 includes the U-phase winding 5u, the V-phase winding 5v and the W-phase winding 5w, and the lead wire L is connected to the U-phase winding 5u. The U-phase lead wire Lu, the V-phase lead wire Lv connected to the V-phase winding 5v, and the W-phase lead wire Lw connected to the W-phase winding 5w. The lead wire Lv and the W-phase lead wire Lw are provided with three lead-out holes 19b for leading out individually and independently. In the cylindrical linear motor 1 configured as above, the U-phase lead wire Lu, the V-phase lead wire Lv, and the W-phase lead wire Lw are led out to the outside independently from the corresponding lead-out holes 19b. The lead wire Lu, the V-phase lead wire Lv, and the W-phase lead wire Lw can be separated from each other. Therefore, according to the cylindrical linear motor 1 configured as described above, good insulation between the phases of the windings 5u, 5v, 5w of each phase can be realized. When the lead-out holes 19b are provided at equal intervals in the circumferential direction of the cover 17, the U-phase lead wire Lu, the V-phase lead wire Lv, and the W-phase lead wire Lw can be most separated from each other, so that the insulating property is improved.

  Further, the tubular linear motor 1 of the present embodiment is housed in the gap G and has a U-phase connecting portion 27u that connects the U-phase winding 5u and the U-phase lead wire Lu, and the V-phase windings 5v and V. An annular or arc-shaped relay stand 27 having a V-phase connecting portion 27v for connecting the phase lead wire Lv and a W-phase connecting portion 27w for connecting the W-phase winding 5w and the W-phase lead wire Lw is provided. The phase connecting portion 27u, the V phase connecting portion 27v, and the W phase connecting portion 27w are provided at positions separated from each other in the circumferential direction of the relay stand 27. According to the tubular linear motor 1 configured in this way, the windings 5u, 5v, 5w of each phase and the lead wires Lu, Lv, Lw of each phase can be arranged at positions separated from each other in the gap G. Good insulation between the phases of the windings 5u, 5v, 5w of each phase can be realized.

  Further, the tubular linear motor 1 of the present embodiment includes a small diameter portion (cover holding member) 25b provided on the outer periphery of the rod 11 and closer to the base end side than the armature 2, and the cover 17 has the outer periphery of the rod 11. And a ring-shaped cover end 18 that is tubular and has one end fitted to the outer periphery of the cover end 18 and the other end attached to the outer periphery of the small diameter portion (cover holding member) 25b (elastic body). ) 26 and a cover tube 19 fitted to the connector 26. According to the cylindrical linear motor 1 configured as described above, since eccentricity and inclination are allowed with respect to the rod 11, the cover 17 is not strongly pressed against the head cap 15 even if the rod 11 is bent, and the smoothness is ensured. Can be expanded and contracted.

  Further, in the tubular linear motor 1 of the present embodiment, the non-magnetic inner tube 9 provided on the inner circumference of the field 6 and the inner tubes 9 provided on both axial sides of the core 3 of the rod 11 are provided. The slider 25, which has a plurality of annular sliders 21b and 25 slidably contacting the inner circumference and is arranged on the most proximal side of the rod among the sliders 21b and 25, has a small outer diameter on the proximal side of the rod 11. Has a small diameter portion 25b to which a seal ring (elastic body) 26 is attached, and the small diameter portion 25b serves as a cover holding member. According to the tubular linear motor 1 configured as described above, it is not necessary to provide a separate cover holding member, the number of parts is reduced, the cover 17 can be attached to the rod 11, and the field of the armature 2 is reduced. The eccentricity with respect to 6 can be prevented. The cover holding member may be provided separately from the slider 25.

  In addition, in the tubular linear motor 1 according to the present embodiment, the cover cylinder 19 includes the ventilation hole 19c that allows the gap G to communicate with the inside of the inner tube 9. The vent hole 19c always faces the inner tube 9 even when the tubular linear motor 1 expands and contracts, and communicates the gap G to the room inside the inner tube 9 and on the left side of the slider 25. According to the tubular linear motor 1 configured as described above, the room on the left side of the slider 25 in the inner tube 9 that is expanded / contracted by the expansion / contraction operation of the cylindrical linear motor 1 is always communicated with the gap G. The pressure fluctuations in the room are alleviated, and the cylindrical linear motor 1 can smoothly expand and contract.

  Further, in the tubular linear motor 1 of the present embodiment, since the elastic body is the ring-shaped seal ring 26 that seals between the small diameter portion (cover holding member) 25b and the cover tube 19, the elastic body is provided through the inside of the cover 17. Water and dust can be prevented from entering the inner tube 9 or the armature 2.

  Further, the tubular linear motor 1 of the present embodiment includes a stroke sensor S in which the rod 11 has a tubular shape and is inserted into the rod 11 to detect the position of the rod 11 with respect to the field 6. S is a core (detection target) 31 fixed to the field 6 and inserted into the rod 11, and a sensor body 30 housed in the rod 11 and detecting the position of the core (detection target) 31. And have. In the cylindrical linear motor 1 configured as described above, the stroke sensor S is housed in the rod 11 having the armature 2 on the outer circumference, and the stroke sensor S is accommodated to the armature 2 that generates heat by energization and the field 6 that generates a magnetic field. The stroke sensor S is not directly exposed. Therefore, the stroke sensor S is protected from the heat of the armature 2 and is not exposed to the magnetic field of the field 6, so that the detected position of the armature 2 can be accurately detected. As described above, according to the tubular linear motor 1 of the present invention, the reliability of the detected position of the armature 2 can be improved.

  Furthermore, in the tubular linear motor 1 of the present embodiment, the sensor body 30 is housed in a range that does not face the armature 2 in the rod 11 in the radial direction. According to the tubular linear motor 1 configured as described above, the sensor body 30 and the armature 2 do not radially overlap with each other during the stroke of the tubular linear motor 1, so that the heat of the armature 2 is further reduced. It becomes difficult to be affected, and the reliability of the detected position of the armature 2 can be improved more effectively.

  Further, the tubular linear motor 1 of the present embodiment is provided with a guide rod 16 which is connected to the field 6 and slidably inserted into the rod 11, and the core (detection target) 31 is attached to the guide rod 16. It is installed. According to the tubular linear motor 1 configured as described above, the sensor core (detection target) 31 that moves with respect to the sensor body 30 is attached to the guide rod 16 that guides the axial movement of the rod 11. Therefore, the eccentricity of the sensor core (detected element) 31 with respect to the sensor body 30 is prevented, and the stroke sensor S can accurately detect the position of the armature 2.

  Further, the rod 11 in the tubular linear motor 1 of the present embodiment is a tubular first rod 20, is tubular and has the core 3 mounted on the outer periphery, and is screwed onto the inner periphery of the first rod 20. The sensor main body 30 is sandwiched between the first rod 20 and the second rod 21 and fixed in the rod 11. According to the tubular linear motor 1 configured as described above, it becomes very easy to fix the stroke sensor S in the rod 11 and to attach the armature 2 to the rod 11, so that a good assembling property can be obtained. To be

  The stroke sensor S may be a magnetostrictive stroke sensor or a linear potentiometer instead of the linear variable differential transformer, and in any case, it is fixed to the field 6. The position of the detected element to be detected may be detected by the sensor body fixed to the rod 11 side.

  Further, in the tubular linear motor 1 of the present embodiment, the teeth 3b have a trapezoidal shape in which the width of the outer peripheral edge is narrower than the width of the inner peripheral edge. The magnetic path cross-sectional area at the inner peripheral edge becomes wider than in the case of a rectangular shape. Therefore, in the cylindrical linear motor 1 configured as described above, it is easy to secure a large magnetic path cross-sectional area, it is possible to suppress magnetic saturation when the winding 5 is energized, and it is possible to generate a larger magnetic field. Can occur. In addition, in order to improve the thrust, the tooth 3b may have a trapezoidal cross-sectional shape, but may have a rectangular cross-sectional shape or another shape.

  The preferred embodiments of the present invention have been described above in detail, but modifications, variations, and changes can be made without departing from the scope of the claims.

1 ... Cylindrical linear motor, 2 ... Armature, 3 ... Core, 4 ... Slot, 5 ... Winding, 5u ... U-phase winding, 5v ... V-phase Winding, 5w ... W phase winding, 6 ... Field, 9 ... Inner tube, 11 ... Rod, 17 ... Cover, 18 ... Cover end, 19 ... Cover Cylinder, 19b ... Outlet hole, 19c ... Vent hole, 21b, 25 ... Slider, 25b ... Small diameter portion (cover holding member), 26 ... Seal ring (elastic body), 27 ...・ Relay stand, 27u ... U phase connection part, 27v ... V phase connection part, 27w ... W phase connection part, G ... void, L ... lead wire, Lu ... U phase Lead wire, Lv ... V phase lead wire, Lw ... W phase lead wire

Claims (7)

With a rod
An armature that has a tubular shape and is mounted on the outer periphery of the rod, and an armature that has windings mounted on slots provided on the outer periphery of the core,
A cover that covers the outer periphery of the rod and forms an annular gap between the rod and the cover,
A field magnet having a cylindrical shape, in which the rod, the cover, and the armature are axially movably inserted so that N poles and S poles are alternately arranged in the axial direction,
A cylindrical linear motor comprising: a lead wire that is housed in the space, has one end led out of the cover, and the other end connected to the winding. The winding has a U-phase winding, a V-phase winding and a W-phase winding,
The lead wire includes a U-phase lead wire connected to the U-phase winding, a V-phase lead wire connected to the V-phase winding, and a W-phase lead wire connected to the W-phase winding,
The cylindrical linear motor according to claim 1, wherein the cover has three lead-out holes that lead out the U-phase lead wire, the V-phase lead wire, and the W-phase lead wire, independently of each other. . A U-phase connecting portion that is housed in the space and that connects the U-phase winding and the U-phase lead wire; a V-phase connecting portion that connects the V-phase winding and the V-phase lead wire; An annular or arc-shaped relay stand having a W-phase winding and a W-phase connecting portion that connects the W-phase lead wire,
The cylindrical linear motor according to claim 2, wherein the U-phase connecting portion, the V-phase connecting portion, and the W-phase connecting portion are provided at positions separated from each other in the circumferential direction of the relay stand. . A cover holding member provided on the outer periphery of the rod and on the proximal side of the armature,
The cover is an annular cover end provided on the outer periphery of the rod, and an elastic body that is tubular and has one end fitted to the outer periphery of the cover end and the other end attached to the outer periphery of the cover holding member. The cylindrical linear motor according to any one of claims 1 to 3, further comprising a cover cylinder fitted therein. A non-magnetic inner tube provided on the inner circumference of the field,
A plurality of annular sliders that are provided on both axial sides of the core of the rod and are in sliding contact with the inner circumference of the inner tube;
Among the sliders, the slider arranged on the most proximal side of the rod has a small diameter portion on the proximal side of the rod, the outer diameter being small and the elastic body being mounted,
The cylindrical linear motor according to claim 4, wherein the small diameter portion is used as the cover holding member. The cylindrical linear motor according to claim 5, wherein the cover cylinder has a ventilation hole that communicates the gap with the inside of the inner tube. The cylindrical linear motor according to claim 4 or 5, wherein the elastic body is an annular ring that seals between the cover holding member and the cover cylinder.

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