TW201320559A - Cylinder type linear motor - Google Patents

Abstract

Provided is a cylinder type linear motor including an armature section 10 having a cylindrical frame 11, a cylindrical yoke 12 inserted inside the frame 11 and made of a magnetic material, a plurality of ring-shaped coils 13u, 13v, 13w arranged in an axial direction inside the yoke 12 and bearings fixed in two ends of the frame 11, a field magnet section 20 including a large-diameter intermediate portion inserted inside the armature section 10 and having a plurality of permanent magnets 22 arranged in the axial direction and small-diameter shaft portions 24b extending from two sides of the large-diameter intermediate portion in the axial direction and inserted in the bearings, and a cylindrical or ring-shaped buffer member 26 into which the small-diameter shaft portion 24b is inserted, arranged concentrically with the small-diameter shaft portion 24b and fixed onto a step portion of the field magnet section 20 or an end of the frame 11.

Description

Cylinder linear motor

The present invention relates to a cylindrical linear motor.

The cylindrical linear motor includes a U-phase, a V-phase, and a W-phase ring-shaped coil in a plurality of arrays in a cylindrical yoke of a magnetic system in a magnetic yoke. a magnetic field portion of a mover, in which a plurality of permanent magnets are interposed in the axial direction with the N poles and the S poles facing each other via a magnetic plate-shaped spacer. a shaft in the armature portion; and a bearing portion such as a linear bushing or a ball bushing, which are provided at both end portions of the armature portion and support the shaft in a freely movable manner in the axial direction .

In the above-described cylindrical linear motor, when the power is turned off during the acceleration operation, when the control is invalid, the runaway is lost, or the control command is mistaken, the magnetic field portion collides with the bearing portion, and the armature portion or the magnetic field portion is present. The danger of damage. Further, in the case where the cylindrical linear motor is used in the longitudinal placement mode, when the power source is turned off, the magnetic field portion falls due to its own weight and collides with the bearing portion. When the collision is repeated, frictional damage, fatigue damage, and damage of the cylindrical linear motor are caused.

In an injection molding machine in which an injection operation of a resin after melting is performed using a linear motor, an injection molding machine including a cylindrical member having a mold and a hollow portion communicating with a gap of the mold is disclosed. And a heating means for heating and melting the resin material accommodated in the hollow portion; a screw inserted into the hollow portion and on the shaft a direction advance and retreat drive; the movable portion of the linear motor has an output shaft coupled to the rear end portion of the screw, and the output shaft is moved in the axial direction to cause the molten resin to be ejected from the hollow portion toward the gap of the mold; a mount portion having a linear guide for supporting and guiding the movable portion of the linear motor, and a buffer member formed of a spring or a urethane cushion a portion installed at each of the front and rear frame portions of the front and rear of the linear motor when the stroke limit is reached, for absorbing and reducing the collision of the movable portion of the linear motor The impact force (for example, refer to Patent Document 1).

Furthermore, a linear motor is disclosed which is composed of a fixed portion and a movable portion, wherein the fixed portion is mounted on the upper and lower sides of the casing by a casing which is also used as a yoke. a plurality of salient pole cores on the inner wall surface and coils respectively wound around the iron core, and the movable portion is transmitted by the yoke and a plurality of permanent magnets attached to both sides thereof and the movement of the movable portion in the axial direction toward the outside The output shaft is configured to pass through the through hole of the casing and is pulled outward, and the energy of the movable portion is absorbed at the end surface 2 of the casing in the axial direction. For example, two cushion members made of an elastomer of rubber (for example, Patent Document 2).

(Patent Document 1) Japanese Patent Laid-Open Publication No. 2002-355868

(Patent Document 2) Japanese Laid-Open Patent Publication No. Hei 07-232642 (pages 3, 4, and 1)

However, according to the conventional technique disclosed in Patent Documents 1 and 2, the two cushion members are disposed at two places above or below the output shaft. Therefore, there are problems with a large number of parts. Further, when the movable portion first hits either of the two cushioning members, there is a problem in that the movable portion and the output shaft act as bending stresses, and a bias load is applied to the bearing that supports the output shaft. Further, since the cushion member is disposed outside the motor, the deterioration of the cushion member is intensified and the design property is impaired.

The present invention has been made in view of the above circumstances, and an object of the invention is to provide a cylindrical linear motor including a cushion member having a small number of parts, low cost, high reliability, little deterioration, and excellent design.

In order to solve the above problems and achieve the object, the present invention is characterized in that the armature portion includes a cylindrical frame and a cylindrical yoke embedded in the magnetic body of the casing, and arranged in the axial direction. a plurality of ring coils in the yoke and bearings fixed to both ends of the frame; and a magnetic field portion inserted into the armature portion and having a plurality of axial directions a large-diameter intermediate portion of the permanent magnet and a small-diameter shaft portion extending from the large-diameter intermediate portion toward the axial direction and inserted into the bearing, and forming a bracket-shaped shaft; and a cylindrical or annular shape The cushioning member is inserted into the small-diameter shaft portion and disposed coaxially with the small-diameter shaft portion, and is fixed to a step portion of the magnetic field portion or an end portion of the frame body.

The cylindrical linear motor of the present invention has a small shaft portion for insertion and The cylindrical or annular cushioning member is disposed coaxially with the small-diameter shaft portion and fixed to the step portion of the stepped shaft or the end portion of the frame body, so that the number of components of the cushioning member is small, and the cost is low and the reliability is high. efficacy.

Hereinafter, an embodiment of the tubular linear motor of the present invention will be described in detail based on the drawings. Further, the present invention is not limited to the embodiment.

(Embodiment 1)

1 is a longitudinal cross-sectional view showing a tubular linear motor according to a first embodiment of the present invention, FIG. 2 is an enlarged view of a portion A of the first embodiment, and FIG. 3 is a view showing a mover of the cylindrical linear motor of the first embodiment ( Mover) A longitudinal section view of the state of moving to the left.

As shown in Figs. 1 to 3, the cylindrical linear motor 91 of the first embodiment has a cylindrical armature portion 10 serving as a stator and a magnetic field portion 20 serving as a mover. The magnetic field portion 20 and the armature portion are provided. 10 is coaxially inserted and disposed in the armature portion 10, and the intermediate portion is formed in a shape of a large diameter.

The armature portion 10 includes a cylindrical frame body 11 made of a non-magnetic system such as aluminum or resin, and a cylindrical yoke 12 made of a magnetic metal embedded in the frame body 11 and arranged in the yoke in the axial direction. a plurality of annular U-phase coils 13u, V-phase coils 13v, and W-phase coils 13w in 12; an annular insulating plate 14 for insulating between U, V, and W-phase coils 13u, 13v, and 13w; a bobbin 15 of the V, W phase coils 13u, 13v, 13w (the annular insulating plate 14 and the bobbin 14 can be integrally formed by resin); and fixed to both ends of the frame 11 Bearing holder 16; and linear bushing or ball bushing held by bearing retainer 16 Bearings such as (ball bushing).

The magnetic field unit 20 includes a pipe 21 made of a non-magnetic material such as stainless steel (SUS304) or aluminum, and a plurality of thick plates arranged in the tube 21 in the axial direction. The permanent magnet 22; and a spacer 23 made of a magnetic metal inserted between the adjacent permanent magnets 22. The permanent magnets 22 are disposed such that the N poles and the S poles face each other with the spacer 23 interposed therebetween.

At both end portions of the tube 21, a large diameter portion 24a of the attached step shaft 24 is embedded, and the small diameter shaft portion 24b of the attached step shaft 24 extends from the tube (large diameter intermediate portion) 21 toward both sides in the axial direction. . In the field portion 20 of the mover, the large diameter portion 24a of the attached step shaft 24 is fitted to both end portions of the tube 21, and the entire portion is formed to have a thick portion having a thick central portion. The small-diameter shaft portion 24b of the attached differential shaft 24 is movably supported by the bearing 17 at both end portions of the armature portion 10 in the axial direction.

In the one side (the left side of the first figure), the small-diameter portion 24b of the small-diameter shaft portion 24b has a large-diameter portion 24a-side root portion (the step portion of the field portion 20), and is made of a non-magnetic material (aluminum, resin, etc.). A ring spring holder 25. A spiral groove is provided in the outer peripheral portion of the spring holder 25, and a small-diameter shaft portion 24b through which the stepped shaft 24 is inserted is attached to the spiral groove, and is disposed coaxially with the small-diameter shaft portion 24b as a cylindrical shape or a ring. A coil spring 26 of the cushioning member. Further, although not shown, the spring holder 25 and the coil spring 26 may be attached to the small-diameter shaft portion 24b of the attachment shaft 24 on the other side (the right side of the first figure).

The cylindrical linear motor 91 is provided on the armature portion (stator) 10 a magnetic sensor (Hall device) that detects the position of the magnetic pole of the magnetic field portion (mover) 20 or detects the moving position of the magnetic field portion 20 by a linear encoder, and Based on the detected position information, energization of the U, V, and W phase coils 13u, 13v, and 13w is switched, and the field portion 20 is linearly driven in the axial direction along the armature portion 10.

When the power supply is turned off during the acceleration operation of the cylindrical linear motor 91, the control is invalid, the control is lost, or the control command is mistaken, and the magnetic field portion 20 is out of control, as shown in Fig. 3, the magnetic field portion is attached. The left front end portion of the coil spring 26 of 20 collides with the right end surface of the bearing holder 16 of the armature portion 10, and the coil spring 26 is compressed to absorb the kinetic energy of the magnetic field portion 20, thereby mitigating the impact. The wire diameter or the turn number of the coil spring 26 is determined in accordance with the kinetic energy of the magnetic field portion 20.

Since the cylindrical linear motor 91 of the first embodiment is attached to the stepped portion of the differential shaft 24 and has one coil spring 26 coaxially attached to the small-diameter shaft portion 24b, the number of parts is small and the coil spring 26 is generated. The axisymmetric repulsive force does not act as a bending stress in the small diameter shaft portion 24b.

(Embodiment 2)

Fig. 4 is a partially enlarged longitudinal sectional view showing a second embodiment of the tubular linear motor of the present invention. As shown in Fig. 4, the cylindrical linear motor 92 of the second embodiment is attached to the large-diameter portion 24a side root portion (segment portion) of the small-diameter shaft portion 24b of the stepped shaft 24, and has an annular cushioning member embedded therein. O-ring 26a made of soft rubber.

The O-ring 26a is fixed to the large-diameter portion 24a side root portion of the small-diameter shaft portion 24b of the attachment shaft 24 by its own tight-fitting action. (Segment section), so there is no need to hold a holder type part. Even if the coil spring 26 is replaced with the O-ring 26a, the same effect as the coil spring 26 can be achieved, and it is low-cost as a cushioning member.

(Embodiment 3)

Fig. 5 is a longitudinal sectional view showing a third embodiment of the cylindrical linear motor of the present invention, and Fig. 6 is an enlarged view of a portion B of Fig. 5. As shown in Fig. 5 and Fig. 6, the cylindrical linear motor 93 of the third embodiment has a cylindrical spring holder 25a embedded in the small diameter hole 11a at the end of the casing 11. An end flange 25aa is provided at an end portion of the spring holder 25a, and an end portion of the coil spring 26 as a cushioning member housed in the spring holder 25a is engaged with the inner flange 25aa. The small-diameter shaft portion 24b of the attached step shaft 24 protrudes outward through the coil spring 26.

When the magnetic field portion 20 is out of control, the side surface of the large diameter portion 24a of the attached differential shaft 24 collides with the right end surface of the coil spring 26, and the coil spring 26 is compressed to absorb the kinetic energy of the magnetic field portion 20 and to alleviate the impact. As described above, even if the coil spring 26 is attached to the end portion of the armature portion 10, the same effect as that attached to the field portion 20 can be achieved. When the coil spring 26 is attached to the armature portion (stator) 10 side, the weight of the magnetic field portion (mover) 20 does not increase, so that the driving characteristics of the field portion 20 are not affected.

(Embodiment 4)

Fig. 7 is a partially enlarged longitudinal sectional view showing a fourth embodiment of the tubular linear motor of the present invention. As shown in Fig. 7, the cylindrical linear motor 94 of the fourth embodiment has a cylindrical O-ring holder 25b embedded in the small-diameter hole 11a at the end of the casing 11. At the end of the O-ring holder 25b, The large inner diameter portion 25ba has an O-ring 26b as a cushioning member engaged with the large inner diameter portion 25ba. The small-diameter shaft portion 24b of the attached differential shaft 24 passes through the O-ring 26b and protrudes outward without coming into contact with the O-ring 26b.

When the magnetic field portion 20 is out of control, the side surface of the large diameter portion 24a of the attached differential shaft 24 collides with the right end surface of the O-ring 26b, and the O-ring 26b is compressed to absorb the kinetic energy of the magnetic field portion 20 and to alleviate the impact. As described above, even if the O-ring 26b is attached to the end portion of the armature portion 10, the same effect as that attached to the field portion 20 can be achieved.

(Embodiment 5)

Fig. 8 is a partially enlarged longitudinal sectional view showing a fifth embodiment of the tubular linear motor of the present invention. As shown in Fig. 8, the cylindrical linear motor 95 of the fifth embodiment has a cylindrical buffer member embedded in the root portion (segment portion) of the large-diameter portion 24a of the small-diameter shaft portion 24b of the stepped shaft 24 Elastomer 26c. The cylindrical elastic body 26c is fixed to the small-diameter shaft portion 24b of the attachment differential shaft 24 by its own tight-knit action. Even if the tubular elastic body 26c is used instead of the O-ring 26a of the second embodiment, the same effect as the O-ring 26a can be achieved.

(Embodiment 6)

Fig. 9 is a partially enlarged longitudinal sectional view showing a sixth embodiment of the cylindrical linear motor according to the present invention, and Fig. 10 is a partially enlarged longitudinal sectional view showing a deformed state of the cushioning material at the time of collision of the cylindrical linear motor of the sixth embodiment. As shown in Fig. 9 and Fig. 10, the cylindrical linear motor 96 of the sixth embodiment has a cylindrical elastic body 26d as a cushioning member embedded in the small diameter hole 11a at the end of the casing 11. The small diameter shaft portion 24b of the attached differential shaft 24 is passed through the cylinder The elastic body 26d protrudes outward without coming into contact with the cylindrical elastic body 26d.

When the magnetic field portion 20 is out of control, the side surface of the large diameter portion 24a of the attachment difference shaft 24 collides with the right end surface of the cylindrical elastic body 26d, and the cylindrical elastic body 26d is compressed to absorb the kinetic energy of the magnetic field portion 20, and is moderated. Impact. Further, as shown in Fig. 10, the cylindrical elastic body 26d is compressed and expanded on the inner side to be pressed against the small-diameter shaft portion 24b of the attachment differential shaft 24, so that the collision can be alleviated by the frictional force. When the tubular elastic body 26d is attached to the armature portion (stator) 10 side, since the weight of the magnetic field portion (mover) 20 does not increase, the driving characteristics of the magnetic field portion 20 are not affected.

(Embodiment 7)

Fig. 11 is a partially enlarged longitudinal sectional view showing a seventh embodiment of the tubular linear motor of the present invention. As shown in Fig. 11, the cylindrical linear motor 97 of the seventh embodiment has a permanent magnet 26e as a cylindrical or annular cushioning member embedded in the small diameter hole 11a at the end of the casing 11. The magnetic pole (S pole) inside the permanent magnet 26e attached to the end portion of the casing 11 and the magnetic pole (S pole) on the end side of the permanent magnet 22 of the field portion 20 are the same magnetic pole and mutually repel each other. . The small-diameter shaft portion 24b of the attached differential shaft 24 passes through the permanent magnet 26e and protrudes outward without coming into contact with the permanent magnet 26e.

When the magnetic field portion 20 is out of control, the magnetic pole (S pole) on the end side of the permanent magnet 22 of the field portion 20 approaches the magnetic pole (S pole) on the inner side of the permanent magnet 26e attached to the end portion of the casing 11, and The non-contact method is resistant to repulsive forces and mitigates impacts during a collision. If a strong permanent magnet 26e is used, then The magnetic field portion 20 can be stopped in a non-contact manner. Since the permanent magnet 26e is attached to the armature portion (stator) 10 side, the weight of the field portion (mover) 20 does not increase, and the driving characteristics of the field portion 20 are not affected. In addition, when a cylindrical permanent magnet is used as the permanent magnet 22 of the field portion 20, it can be used in common with the permanent magnet 26e attached to the end portion of the casing 11.

(Embodiment 8)

Fig. 12 is a partially enlarged longitudinal sectional view showing the eighth embodiment of the tubular linear motor of the present invention. As shown in Fig. 12, the cylindrical linear motor 98 of the eighth embodiment is a ring-shaped coil (electromagnet) 26f as a cushioning member, which is extended to the end portion of the casing 11. The small-diameter shaft portion 24b of the attached step shaft 24 passes through the coil 26f and protrudes outward without coming into contact with the coil 26f.

When the field portion 20 is out of control, the magnetic pole (N pole) on the end side of the permanent magnet 22 of the field portion 20 is close to the coil (electromagnet) 26f attached to the end portion of the frame 11, and by the coil (electromagnetic The magnetic flux generated by the iron) 26f is subjected to the repulsive force in a non-contact manner, and the impact at the time of collision can be alleviated. When a strong coil (electromagnet) 26f is used, the field portion 20 can be stopped in a non-contact manner. Since the coil (electromagnet) 26f is attached to the armature portion (stator) 10 side, the weight of the magnetic field portion (mover) 20 does not increase, and the driving characteristics of the field portion 20 are not affected. The coil (electromagnet) 26f can be integrated with the U, V, and W phase coils 13u, 13v, and 13w of the armature portion 10. Further, the coil (electromagnet) 26f may be a short-circuit coil. When it is a short-circuit coil, the magnetic flux of the field portion 20 is interlinkage, and the short-circuit current flows out and can be operated by dynamic braking.

Further, in the first to eighth embodiments, the armature portion 10 is referred to as a stator, and the field portion 20 is referred to as a mover. However, the armature portion 10 may be used as a mover, and the field portion 20 may be regarded as a stator.

10‧‧‧ Armature (stator)

11‧‧‧ frame

11a‧‧‧Small hole

12‧‧‧ yoke

13u‧‧‧U phase coil

13v‧‧‧V phase coil

13w‧‧‧W phase coil

14‧‧‧Circular insulation board

15‧‧‧winding tube

16‧‧‧Bearing holder

17‧‧‧ bearing

20‧‧‧Magnetic field (mover)

21‧‧‧ tube

22‧‧‧ permanent magnet

23‧‧‧ spacers

24‧‧‧Segment differential axis

24a‧‧‧The Great Trails Department

24b‧‧‧ Small diameter shaft

25, 25a‧‧‧ Spring Holder

25aa‧‧‧ inner flange

25b‧‧‧O-ring holder

25ba‧‧‧large inner diameter

26‧‧‧Helical spring (buffer member)

26a, 26b‧‧O ring (buffer member)

26c, 26d‧‧‧Cylindrical elastomer (buffer member)

26e‧‧‧Permanent magnet (buffer member)

26f‧‧‧ coil (electromagnet, cushioning member)

91 to 98‧‧‧ tubular linear motor

Fig. 1 is a longitudinal sectional view showing a first embodiment of a tubular linear motor according to the present invention.

Fig. 2 is an enlarged view of a portion A of Fig. 1.

Fig. 3 is a longitudinal sectional view showing a state in which the mover of the cylindrical linear motor of the first embodiment is moved to the left.

Fig. 4 is a partially enlarged longitudinal sectional view showing a second embodiment of the tubular linear motor of the present invention.

Fig. 5 is a longitudinal sectional view showing a third embodiment of the tubular linear motor of the present invention.

Fig. 6 is an enlarged view of a portion B of Fig. 5.

Fig. 7 is a partially enlarged longitudinal sectional view showing a fourth embodiment of the tubular linear motor of the present invention.

Fig. 8 is a partially enlarged longitudinal sectional view showing a fifth embodiment of the tubular linear motor of the present invention.

Fig. 9 is a partially enlarged longitudinal sectional view showing a sixth embodiment of the tubular linear motor of the present invention.

Fig. 10 is a partially enlarged longitudinal sectional view showing a deformed state of the cushioning material at the time of collision of the cylindrical linear motor of the sixth embodiment.

Fig. 11 is a partially enlarged longitudinal sectional view showing a seventh embodiment of the tubular linear motor of the present invention.

Fig. 12 is a partially enlarged longitudinal sectional view showing the eighth embodiment of the tubular linear motor of the present invention.

10‧‧‧ Armature (stator)

11‧‧‧ frame

12‧‧‧ yoke

13u‧‧‧U phase coil

13v‧‧‧V phase coil

13w‧‧‧W phase coil

14‧‧‧Circular insulation board

15‧‧‧winding tube

20‧‧‧Magnetic field (mover)

21‧‧‧ tube

22‧‧‧ permanent magnet

23‧‧‧ spacers

24‧‧‧Segment differential axis

24a‧‧‧The Great Trails Department

24b‧‧‧ Small diameter shaft

25‧‧‧Spring Holder

26‧‧‧Helical spring (buffer member)

91‧‧‧Cylinder linear motor

Claims (7)

A cylindrical linear motor comprising: an armature portion; a tubular frame body; a cylindrical yoke magnetically embedded in the frame body; and a plurality of annular rings arranged in the yoke in the axial direction a coil and a bearing fixed to both end portions of the frame; the magnetic field portion is inserted into the armature portion, and has a large-diameter intermediate portion in which a plurality of permanent magnets are arranged in the axial direction, and an intermediate portion from the large-diameter portion a shaft portion extending in the axial direction and inserted into the small-diameter shaft portion of the bearing, and forming a bracket shaft shape; and a cylindrical or annular cushioning member for inserting the small-diameter shaft portion and coaxial with the small-diameter shaft portion The ground body is disposed in the frame body and is fixed to the step portion of the magnetic field portion or the end portion of the frame body. The tubular linear motor according to claim 1, wherein the cushioning member is a coil spring. The tubular linear motor according to claim 1, wherein the cushioning member is an O-ring. The tubular linear motor according to claim 1, wherein the cushioning member is a cylindrical elastic body. The tubular linear motor according to claim 1, wherein the cushioning member is a permanent magnet. The tubular linear motor according to claim 1, wherein the cushioning member is an electromagnet. The tubular linear motor according to claim 6, wherein the electromagnet is a short-circuit coil.