JPS5986471A - Brushless linear motor - Google Patents

Abstract

PURPOSE:To prevent movable elements symmetrically disposed at both side surfaces of a stator from being bent by arranging coils on both side surfaces of a stator yoke to form the stator, symmetrically dispose the elements on the stator and integrally coupling the elements, thereby operating attracting forces to the stator in good balance. CONSTITUTION:Base plates 9 are mounted on both side surfaces of a stator yoke 8, in which a guide 7 for guiding rollers 5 are formed, and a coil 10 and hole sensors 11 are longitudinally continuously arranged on both plates 9 to form a stator 13. Movable elements 12a, 12b are disposed on both side surfaces of the stator 13, and the elements 12a, 12b are integrally coupled by a reinforcing plate 14 at both sides.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brushless linear motor equipped with a permanent magnet field on the movable side and a coil on the stator side.

FIG. 1 (A>5 (B) and (C) is a plan view, a side view, and a front view showing a conventional linear motor of this type. In the figure, 1 is a movable element, and this movable element 1 is A substantially rectangular movable yoke 2, a permanent magnet 3 disposed at the center of the lower surface of the movable yoke 2, a shaft 4 fixed horizontally at the four corners on both sides of the movable yoke 20, and movement of the movable element 1. It consists of a roller 5 rotatably attached to each shaft 4 and a roller 7 that is rotatably attached to each shaft 4 to smoothly perform the
t, where the permanent magnets 3 have a structure in which they are magnetized alternately along the direction of movement of the movable element 1.

Reference numeral 6 denotes a stator, and the stator 6 includes a long stator yoke 8 having grooves or stepped guide portions 7 formed on both sides of one side for guiding the roller 5, and a stator yoke 80 attached to one side. A rolled long board 9 and a rolled coil 1 wound around a winding frame and continuously disposed on the board 9 along the longitudinal direction.
0 and a substrate 9 located inside each coil 10.
The coil 1o and the Hall sensor 11 are arranged on the top of the permanent magnet 3p for detecting the magnetic field generated from the permanent magnet 3p. connected to the circuit
ing.

The operating principle of this configuration is that several coils 10 of the stator 6 are located in the magnetic field generated by the permanent magnet 3 of the mover 1, so when a current is applied to the coils 10, the energized coils 10 A current force according to Fleming's left-hand rule acts on. However, since each coil 10 is fixed to the substrate 9, a thrust acts as a reaction force on the permanent magnet 3, and this thrust causes the movable element 1 to move along the longitudinal direction of the stator 6.

A linear motor using such a system does not require brushes because the magnetic field of the permanent magnet 3 is detected by the Hall sensor 11 to control the current to the coil 10, and the movable element 1
Since the structure has the permanent magnet 3 on the side and the coil 10 on the stator 6 side, the lead comes out from the movable element 1 side, which has the advantage of being easy to assemble and having a long life. have.

However, on the other hand, since the stator yoke 8 on the stator 6 side forms part of the magnetic path of the magnetic flux generated from the permanent magnet 3 on the movable element 1 side, an attractive force is generated between the movable element 1 and the stator 6. According to experiments, this suction force is about 10 times the thrust force that moves the movable element 1, which has the drawback of causing various permanent positions as described below.

In other words, since the attractive force acting between the mover 1 and the stator 6 is large, the stator 6 bends and the gap between the mover 1 and the stator 6 becomes uneven, which causes the thrust to decrease. The movable element 1 changes due to the fluctuation and the large suction force.
The wear of the guide portion 1 of the stator yoke 8 on the stator 6 side that is engaged with the rollers 5 and 7'L on the side increases.

Also, the thrust is the suction force. 1. Unless the coefficient of friction between the shaft 4 and the roller 5 is set to 01 or less, the friction force will be greater than the thrust force and the movable element 1 will not move. Therefore, it is necessary to use ball bearings for the roller 5, which makes it expensive, and if the thrust is further increased, NVC
Since the suction force also increases proportionally, there are drawbacks such as an increase in the frictional force of the rollers 5.

The purpose of the present invention is to solve the drawback of stiffness, and for this purpose, a stator is constructed by disposing coils on both sides of a stator yoke, and two movers are arranged symmetrically on both sides of this stator. By integrally connecting both rotating elements through the reinforcing plate, warpage 9 of the stator due to suction force does not occur.
The movable member is also characterized by a movable structure so that the suction force acting on the movable element is applied to the reinforcing plate.

To explain the following with reference to the drawings, FIGS. 2A, 2B, and 2C are a plan view, a side view, and a front view showing an embodiment of the brushless linear motor according to the present invention.
a and 12b are movable elements, and these rotary elements 12a and 12b have a movable element yoke 2 and a permanent magnet 3, similar to the movable element 1 in FIG.
, a shaft 4, and a roller 5, respectively.

13 is a stator, and this stator 13 is basically constructed using the same parts as the stator 6 in FIG. Substrates 9 are attached to both sides of the child cork 8, and a coil 10 and a hall processor 11 are continuously disposed on both substrates 9 in the longitudinal direction. The rotators 12a and 12b extend over the h1, and the rotators 12a and 12b are integrally joined by reinforcing plates 14 on both sides.

Although the reinforcing plate 14 is fixed to the shaft 4 in the figure, it may be fixed to the movable yoke 2vc, and the guide portions T are formed on both sides of the stator yoke 8, but may be formed only on one side. .

Further, the coil 10 and the Hall sensor 11 are connected to an external drive control circuit (not shown) via a substrate 9.

The operating principle of the brushless linear motor with such a configuration is the same as that in FIG.
The electromagnetic repulsive force acting between the permanent magnet 3 and the coil 10 of the stator 13 acts as a thrust, and this thrust causes the movers 12a and 12b to move together along the longitudinal direction of the stator 13. Therefore, during this movement, the stator 13 and both rotators 12a.

A suction force of about 10 times the thrust acts between the stator 12b and the stator 13, but since the stator 13 is attracted from both sides in a well-balanced manner,
The stator 13 does not warp, and both rotators 12a
, 12b is applied to the reinforcing plate 14 and not to the roller 5.0 As explained above, in the present invention, the stator is constructed by disposing coils on both sides of the stator yoke. At the same time, the movable elements are placed on both sides of the stator, and both rotating elements are integrally connected to the reinforcing plate, so that the suction force acts on the stator from both sides in a well-balanced manner. 9. As a result, the stator does not warp and the gap with the mover can be kept constant, reducing thrust fluctuations and reducing wear on the roller and stator yoke guides. The effect of being able to do this is obtained.

In addition, all the suction force acting on the mover is applied to the reinforcing plate 9.
, since it is not applied to the roller at all, the frictional force on the roller part is reduced, and as a result, ball bearings are not required, resulting in lower costs, less wear on the roller part, and a longer lifespan. Furthermore, various effects such as an easy increase in thrust can be obtained.

[Brief explanation of drawings]

FIG. 1(A) is a plan view showing a conventional brushless linear motor, FIG. 1(B) is a side view thereof, FIG. 1(C) is a front view thereof, and FIG. 2(A) is a brushless linear motor according to the present invention. A plan view showing an embodiment of the linear motor, FIG. 2(B) is a side view thereof, and FIG. 2(C) is a front view thereof. 2... Mover yoke 3... Permanent magnet 4... Shaft 510. Roller 7... Guide portion 8... Stator yoke 9... x plate io... Coil 11... Hall sensors 12a, 12b... Mover 13... Stator 14... Reinforcement Board Patent Applicant: Oki Electric Industry Co., Ltd. Tohoku Oki 1b; Ki Co., Ltd. Agent Patent Attorney: Takashi Kanakura Motorcycle 2Cill (A) (B) (C)

Claims (1)

[Claims] 1. A mover yoke, a mover equipped with a permanent magnet attached to the mover yoke, an elongated stator yoke, and a mover provided continuously along the longitudinal direction of the stator yoke. In a brushless linear motor that consists of a stator equipped with a compact coil, the stator is constructed by arranging coils on both sides of the stator yoke, and the movable element is symmetrically placed on both sides of the stator. A brushless linear motor characterized in that both rotating elements are arranged and integrally connected by a reinforcing plate.