JP2000023449A - Linear motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture an armature of a required length cheaply, by arranging a plurality of iron cores constituting an armature in series, and winding a group of coils of several times of one unit, when each one unit is considered to be composed of coils of three phases of U, V, and W which adjoin the teeth of each iron core. SOLUTION: A partial armature 21 is composed of iron cores 31, U-phase, V-phase, and W-phase coils 32, 33, 34 wound on the iron cores 31, and resin 35 which covers these iron cores 31 and coils 32, 33, 34 and has solidified. Each iron core 31 has an iron core body 41 in the shape of a band plate and nine parallel teeth 42 projecting in one direction from this body 31. On these teeth 42, nine coils 32, 33, 34 in total of three units are wound in that order from the right to the left, when a unit is considered to be composed of three-phase coils 32, 33, 34 of phases U, V, and W adjoining one another. And the left-end coil 34 on the right iron core 31 is phase-W, and the right-end coil 32 of the left iron core 31 is phase-U. Two iron cores 31 are arranged so that the interval between the W-phase coil 34 and the U-phase coil 32 may be set to 2P/3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a linear motor,
For example, the present invention relates to a linear motor suitable for driving an operating member that is reciprocated at a predetermined stroke, such as a feed bar of a press.

In this specification, one magnetic pole pitch P is defined as the distance between the centers of adjacent magnetic poles (New Edition Electrical Engineering Handbook: The Institute of Electrical Engineers of Japan, February 28, 1988)
(Japanese edition, Chapter 12, Chapter 2, Basics of Rotating Machine Design, page 561).

[0003]

The armature of a linear motor is manufactured by a motor manufacturer. Motor manufacturers standardize armature lengths and manufacture a plurality of types of armatures having different lengths according to the standards. This is to increase the mass production effect.

When a reciprocating operating member is driven by a linear motor, an armature having a length corresponding to the stroke of the operating member is required, but if the armature length does not meet the above standards. The armature must be manufactured by special order, which is expensive. In particular, it is extremely expensive to manufacture a long armature that is out of specification.

An object of the present invention is to provide a linear motor capable of manufacturing an armature of a required length at low cost.

[0006]

In a linear motor according to the present invention, a plurality of iron cores constituting an armature are arranged in series, and the teeth of each iron core are adjacent to three phases of a U phase, a V phase and a W phase.
The phase coil is one unit, and a coil group of an integral multiple of the unit is wound around the unit.

In the linear motor according to the present invention, since one armature is constituted by a plurality of iron cores, the length of the iron core can be reduced as compared with the case where one armature is constituted by one iron core. In addition, the size of the mold for manufacturing the iron core can be reduced, and the work of winding the coil around the iron core is easy. Therefore, the armature can be manufactured at low cost.

Further, since a large number of small armatures are manufactured, the mass production effect is improved, the cost is reduced, and the quality is improved. Further, the length of the armature can be freely set in units of the length of one iron core. Further, when the armature is defective, only the defective armature can be replaced.

Further, since the coil group wound around each iron core is a unit of three-phase coils of the adjacent U-phase, V-phase, and W-phase, which is an integral multiple of the unit, the coil group is generated in one unit. Since the generated magnetic flux does not pass between the adjacent iron cores, a uniform and stable magnetic flux can be obtained.

When the pitch of one magnetic pole is P, if the distance between the centers of the closest coils sandwiching the opposite ends of the adjacent iron cores is 2P / 3, the magnets constituting the field are adjacent to each other. The magnetic flux created by the magnet when it is on the opposite end of the iron core works most effectively on the coil, so that the thrust of the linear motor does not decrease.

[0011] Further, at least one of two opposing end faces of the adjacent iron cores is protruded from the base side face of the tooth closest to the end face so as to prevent leakage of magnetic flux of the magnet constituting the field. When the portion is provided, the magnetic force of the magnet can be used effectively.

Further, it is preferable that the space between the end faces is substantially completely filled with the protrusion.

Further, if the coil group wound around all the teeth of the iron core is connected in series with corresponding ones of three phases of U-phase, V-phase and W-phase, the magnet constituting the magnetic field is formed. Regardless of the cores arranged in series, the same current flows through coils of the same phase wound around different cores, so that thrust does not decrease.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, the linear motor includes a fixed-side coil array 11 and a movable-side magnet array 12 arranged in parallel with the coil array 11. The coil array 11 is composed of four partial armatures 21 connected in series so as to be adjacent to each other. The magnet row 12 includes two magnet plates 22 connected in series so as to be in contact with each other.

When a linear motor is used to drive the feed bar of the press, the coil array 11 is fixed to the press frame and the magnet array 12 is fixed to the feed bar. In this case, if one of the partial armatures 21 and the magnet plate 22 is detachably fixed by bolts or the like, and if any of the partial armatures 21 or the magnet plate 22 is defective, Only the armature 21 or the magnet plate 22 can be easily replaced.

The length of each partial armature is L1, the length of each magnet plate is L2, and the moving stroke of the magnet row is St.
Then, St = 4 · L1−2 · L2.

Each of the partial armatures 21 is provided with a coil group of three-phase coils of adjacent U-phase, V-phase and W-phase. In FIG. 1, the coil groups are shown simply as U, V and W symbols. Further, terminals 23 are provided at both ends of the upper surface of each partial armature 21, respectively. Although not shown here, as will be described later, the terminals 23 of the connecting portions of the partial armatures are connected in series.

A magnet plate corresponding to the coil row 11
A large number of magnets are provided on the 22 at equal intervals corresponding to the coil pitch. The magnets are indicated by N and S symbols. Note that the same interval may be set to a half of the coil pitch.

Referring to FIG. 2, of the four partial armatures 21, two adjacent partial armatures 21 are shown. 2
The two partial armatures 21 have the same structure, but may have irregular lengths.

The partial armature 21 includes an iron core 31 and U-phase, V-phase and W-phase coils 32, 33, wound around the iron core 31.
34, and cover these iron cores 31 and coils 32, 33, 34.
It consists of solidified resin 35.

The iron core 31 has a strip-shaped iron core main body 41 and nine parallel teeth 42 projecting in one direction. These teeth 42 have a total of nine coils 32, 33, and 34 in three units from the right in the order of three units of adjacent U-phase, V-phase, and W-phase coils 32, 33, and 34 as one unit. It is wound around the left. How to coil 32, 33, 34
The coil of a certain phase and the coil of another phase do not overlap in the direction in which the phases are arranged.

Regarding the U-phase, the distance between the center of the magnetic pole generated by the U-phase coil 32 and the center of the magnetic pole generated by the U-phase coil 32 between the armature closest to the U-phase coil is 2P.
Becomes The same applies to the V phase and the W phase. Then, the three-phase coils 32, 33, and 34 of the U phase, the V phase, and the W phase
Is 2P / 3. Therefore, the pitch between adjacent teeth 42 is also 2P / 3.

The coil 34 at the left end of the right core 31 has a W phase, and the coil 31 at the right end of the left core 31 has a U phase. Same W
The two iron cores 31 are arranged so that the interval between the phase coil 34 and the U-phase coil 31 is set to 2P / 3. And
There is a gap between the opposite ends of the two iron cores 31. The gap is made of resin to protect the coil ends.
Blocked by 35.

FIG. 3 shows a state in which the U-phase coil 32 is wound around the teeth 42 of the iron core 31. The coil 32 has two cores
31 are wound around the first, fourth and seventh teeth 42, respectively, counted from the right. The winding direction of each coil 42 is clockwise when viewed from the tip side of the teeth 42. In each iron core 31, counting from the right, the first coil 32 and the second coil 32, and the second coil 32 and the third coil 32 are connected by an internal connection 51. The first coil 32 is connected to an input-side external connection terminal 52, and the third coil 32 is connected to an output-side external connection terminal 53. The output side external connection terminal 53 of the right core 31 and the input side external connection terminal 52 of the left core 31 are connected by an external connection 54. Although the U-phase wiring has been described above, the V-phase and the W-phase are similarly wired in series.

FIG. 4 shows a modification of the iron core 31. In this modification, at opposite ends of the two iron cores 31,
The left end face of the right iron core 31 and the right end face of the left iron core 31 are opposed to each other with the above-mentioned gap therebetween.
Are provided so as to extend the respective core bodies 41. Leftward projection 61 from the center of the magnetic pole at the left end of right core 31
The distance to the tip end face and the distance from the center of the magnetic pole at the right end of the left iron core 31 to the tip end face of the right protrusion 62 are respectively P / 3.
It is. Therefore, the tip of the left projection 61 and the right projection
62 The tip surfaces are in contact with each other.

As described above, when the gap between the two iron cores 31 is closed by the protrusion, the magnetic flux from the magnet is prevented from leaking from the gap, and the magnetic flux of the magnet is effectively used.

FIG. 5 shows another modification of the iron core.
The iron core shown in FIG. 5 has teeth 71 between the center of each coil and adjacent coils. The opposite end faces of the two iron cores 31 have two protrusions 7 similar to the protrusions 61 and 62 in FIG.
2 and 73 are provided, respectively.
At the tips of 2, 73, pseudo teeth 74, 75 extending in parallel with the teeth 71 are provided, respectively. The distal end surfaces of both protruding portions 72 and 73 and the opposing side surfaces of pseudo teeth 74 and 75 are in contact with each other.

As described above, the protruding portions 72 and 73 are attached to the end of the iron core 31.
When the dummy teeth 74 and 75 are provided, the coil at the end can be protected in addition to the above-described effect of preventing the leakage of the magnetic flux.

[0030]

According to the present invention, an armature having a required length can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a perspective view of a linear motor according to the present invention.

FIG. 2 is a plan view schematically showing an armature of the linear motor.

FIG. 3 is a perspective view of the armature.

FIG. 4 is a plan view showing a modification of the armature.

FIG. 5 is a plan view showing another modification of the armature.

[Explanation of symbols]

 31 Iron core 32 U-phase coil 33 V-phase coil 34 W-phase coil 42 Teeth 61 Projection 62 Projection P Magnetic pole pitch

Claims (5)

[Claims] 1. A plurality of iron cores constituting an armature are arranged in series, and a U-phase, a V-phase and a W-phase adjacent to teeth of each iron core are provided.
A linear motor having a three-phase coil as one unit and a coil group wound by an integral multiple of that unit as a unit. 2. The linear motor according to claim 1, wherein, when one magnetic pole pitch is P, the distance between the closest coil centers sandwiching opposing ends of adjacent iron cores is 2P / 3. 3. A protrusion protruding from at least one of two opposing end surfaces of adjacent iron cores from a base side surface of a tooth closest to the end surface so as to prevent leakage of magnetic flux of a magnet constituting a field. The linear motor according to claim 1, wherein a portion is provided. 4. The linear motor according to claim 3, wherein a space between the end faces is substantially completely filled with the protrusion. 5. A coil group wound around teeth of all iron cores is connected in series with corresponding ones of three phases of U-phase, V-phase and W-phase. Linear motor according to one of the above.