JPH08182302A - Bearing for linear motor - Google Patents

Abstract

PURPOSE: To prolong the lifetime of a bearing by facilitating the assembling of a bearing unit and reducing the local separation of a sliding surface. CONSTITUTION: The bearing for a linear motor comprises a sliding bearing 31 in which the one end side of a movable element 1 in the lateral direction crossing a longitudinal moving direction is supported by a ball circulation type linear bearing 30 and the other side is supported while sliding a guide shaft 32 disposed at a stator at the U-shaped sliding surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing for a movable magnet type linear motor in which a coil wound around a stator is excited and a mover of a permanent magnet linearly reciprocates along a guide.

[0002]

2. Description of the Related Art The following prior art is found in relation to the movable magnet type linear motor bearing of the present invention. For example, in FIG.
This is the bearing for a movable magnet type DC brushless linear motor shown in [hereinbelow, referred to as "conventional example"]. FIG.
(a) is a plan view in which a part of this conventional example is cut away, and FIG. 4 (b).
Is a side view thereof, and FIG. 4 (c) is a front view thereof. Mover 1
Has one surface facing the armature 2 and the other surface is the second stator yoke
The armature 2 is slidably supported so as to face the armature 2b.
Is the first stator with four coils 21a to 21d mounted on the magnetic pole pieces 23a to 23d in the moving direction of the mover 1 at an interval corresponding to an electrical angle of 300 °, that is, (5/3) times the magnet interval. It is placed on the yoke 22a, and one end of each coil 21a to 21d is commonly
A movable magnet type linear motor is constructed by connecting the other ends to the phase terminals. In order to drive the linear motor of this conventional example, the mover 1 and the armature 2 are moved by a position sensor such as a (magnetic) linear encoder 26 and a linear scale 27.
If the relative position of the armature 2 is detected and a current of 120 ° is supplied to each coil of the armature 2 in accordance with the relative position, thrust in any direction can be generated. In addition, stoppers 25a, 25b of non-magnetic material
Is applied to prevent overrun of the mover 1. In this moveable magnet type linear motor, various high-performance magnets such as iron-neodymium-boron system are used for mover magnets. Thus, in the linear motor, the mover 1 is slidably supported so as to face the armature 2, and the mover 1 that linearly reciprocates is provided between both sides in the lateral direction and the stator (armature 2). Ball bearing type linear bearing 30
It is a structure that slides along the linear guide 29.

[0003]

However, it is 00000.
000, etc. In this conventional example, the use of a ball circulation type linear bearing is not preferable because the number of processing steps and the increase in cost are very large. Here, in the present invention, in this type of linear motor bearing, the assembly of the bearing portion is facilitated, the local deviation of the sliding surface is reduced, the bearing life is improved, and the cost can be reduced. The present invention aims to provide a bearing for a linear motor.

[0004]

In order to solve the above-mentioned problems, the present invention is directed to a linear support for slidably supporting a plate-shaped mover on a stator in a direction parallel to the plate surface. In the motor, one end side of the mover in the horizontal direction crossing the vertical moving direction is supported by a ball circulation type linear bearing, and the other end is supported by a slide bearing. 5. The linear motor bearing according to the preceding paragraph, wherein the sliding bearing portion is configured to slide on the sliding surface of the U-shaped or U-shaped sliding surface provided on the mover, and is guided by a ball circulation type linear bearing. The linear motor bearing according to the preceding paragraph, which is configured by offsetting the guide shaft of the slide bearing portion with respect to the direction. Further, four coils are arranged at substantially equal intervals corresponding to an electrical angle of 360 ° ± 60 °. , An armature in which one end of the coil is commonly connected to the other phase terminals is provided, and a plurality of plate-shaped permanent magnets are arranged for each holding frame provided at a plurality of positions at substantially equal intervals on a plate-shaped non-magnetic body. The linear motor bearing according to the preceding paragraph, wherein the movable element is mounted to form the plate-shaped movable element, and the movable element is slidably supported on one side or both sides of the movable element, and the stator yoke is A bearing for a linear motor is provided with a ball circulation type linear bearing in which a part of the constituent steel plates is cut open, and the cut open parts are cut and raised to form both side surfaces of a substantially U-shaped or U-shaped outer part.

[0005]

The present invention is a linear mover using a ball circulation type linear bearing and a pipe-shaped or substantially U-shaped or U-shaped slide bearing as a bearing, so that the equipment is simple and further changes with time. Even if the sliding part between the slide bearing and the guide shaft causes some positional friction, the guide shaft of the slide bearing is arranged with an offset in the moving direction of the linear motor (linear bearing). As a result, the contact area between the guide shaft and the slide bearing becomes wider depending on the moving position of the mover, sliding is smooth without any problems, the bearing life is improved, and maintenance is easy. It also contributes to flattening.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In all the drawings, the same reference numerals indicate the same members or corresponding members. FIG. 1A is a plan view showing a holding mechanism in which a movable magnet type linear motor including a linear motor bearing according to an embodiment of the present invention is partially cut away,
FIG. 1 (b) is a side view and FIG. 1 (c) is a front view. In this embodiment, one of the bearings on which the mover 1 is supported is modified to a pipe-shaped slide bearing 31, and only one ball circulation type linear bearing 30 is provided. That is, in the mover 1 that slides in the vertical direction, the slide bearing 31 that fits into the guide shaft (guide shaft) 32 supported by the guide support 33 is
Of the linear guide 29 of the mover 1 and 0000
It is possible to smoothly and freely slide along the 00000 guide shaft 32. The slide bearing 31 and the ball circulation type linear bearing 30 may constitute either one or the other of the mover 1, and the selection thereof is not specified. In this way, it is possible to reduce the number of ball circulation type linear bearings 30 and facilitate maintenance.

FIG. 2 (a) is a plan view showing a holding mechanism in which a movable magnet type linear motor including a linear motor bearing according to another embodiment of the present invention is partially cut away, and FIG. 2 (b) is a side view. FIG. 2 (c) is a front view. In this embodiment, when the plain bearing has a pipe shape (cylindrical shape) [see FIG. 1 (c)], relative position friction with the guide shaft 32 sometimes occurs due to aging, and one of the circumferential surfaces The parts may wear unevenly, and the guide shaft should be used in case of malfunction such as increase in friction resistance.
32 and sliding so that the bearing 31 _a transgression line contact, and the slide bearing 31 _a having a substantially U-shaped or U-shaped with inner surface. Further, the offset 34 is provided between the guide shaft 32 and one side of the inner surface of the plain bearing 31 _a , so that the guide shaft 32
A sliding rubbing bias between both bearings 31 _a to prevent the.

FIG. 3 (a) is a plan view showing a holding mechanism in which a movable magnet type linear motor having a linear motor bearing according to another embodiment of the present invention is partially cut away, and FIG. 3 (b) is a side view. FIG. 3 (c) is a front view, and FIG. 3 (d) is an explanatory view showing a state in which the side surface of the ball circulation type linear bearing is cut and raised from the armature yoke. As can be seen from FIG. 4 (c), the linear guide 29 in the inner portion of the ball circulation type linear bearing 30 is the mover 1
The ball circulation type linear bearing 30 of the outer portion of the ball circulation type linear bearing 30 is fixed to the armature (stator). By the way, it is required that the linear motor mounted on the apparatus be as thin as possible. Therefore, in this embodiment, as shown in FIG. 3 (d), as a means for further reducing the thickness of the ball circulation type linear bearing 30 in the outer portion, _a notch is made in the armature yoke 22a made of a steel plate and By cutting and raising the outer side portions of the outer portion, circumferential grooves for rolling balls are engraved on them. Generally, in a linear motor in which the movable part is supported by a ball circulation type linear bearing 30 regardless of the drive system, the bearing part is integrated into the inner part and the outer part, and the completed linear bearing is screwed to the frame of the linear motor. Used by fastening etc. However, when the linear motors are arranged in multiple axes, the number of processing and assembling steps for mounting the linear bearings is large. In this embodiment, the outer portion of the bearing is formed in the main body of the linear motor, the number of assembling steps is reduced, the height of the bearing portion is lowered, and the flattening of the linear motor is facilitated. Thus, not only the thickness of the ball circulating linear bearing 30 is reduced by the thickness of the outer portion, but also the positioning of the ball circulating linear bearing 30 is secondarily obtained.

[0009]

As described above, in the linear motor bearing according to the present invention, a ball circulation type linear bearing and a slide bearing are used together as a bearing, and the slide bearing portion is U-shaped (without a pipe shape). Or it can be a U-shape), and since the guide shaft of the slide bearing (guide shaft) is arranged with an offset with respect to the moving direction of the linear bearing, based on these , The equipment for sliding the mover is simplified, and the contact area between the guide shaft and the slide bearing is widened according to the moving position, thus the life of the bearing is improved, and the outer portion of the bearing is formed in the linear motor body. Not only can the number of assembly steps be reduced, the height of the bearing portion can be lowered, and the flattening of the linear motor can be facilitated. Savings of Maintenance Manual is also obtained.

[Brief description of drawings]

FIG. 1 shows a holding means of a linear motor mover according to an embodiment of the present invention (a) is a partially cutaway plan view (b) is a side view (c) is a front view

FIG. 2 shows a holding means of a linear motor mover according to another embodiment of the present invention. (A) is a partially cutaway plan view (b) is a side view (c) is a front view

FIG. 3 shows a holding means of a linear motor mover according to another embodiment of the present invention. (A) is a partially cutaway plan view (b) is a side view (c) is a front view (d) is Explanatory drawing showing a state in which the side surface of a ball circulation type linear bearing is cut and raised from an armature yoke

FIG. 4 shows a holding means of a linear motor mover in a conventional example (a) is a partially cutaway plan view (b) is a side view (c) is a front view

[Explanation of symbols]

 1 mover 2 armatures 11a, 11b, 11c, 11d, 11e, 11f, 11g permanent magnets 21a, 21b, 21c, 21d coils 22, 22a, 22b armature yokes 23a, 23b, 23c, 23d pole pieces 25a, 25b stoppers 26 Linear encoder 27 Linear scale 28 Rod 29 Linear guide 30,30a Ball circulation type linear bearing 31,31a Sliding bearing 32 Guide shaft (guide shaft) 33 Guide shaft support 41a, 41b Supporter 42 Fixing means

Claims (5)

[Claims] 1. A linear motor that slidably supports a plate-shaped mover on a stator in a direction parallel to the plate surface of the mover in a lateral direction intersecting a vertical moving direction. A bearing for a linear motor characterized in that one end is supported by a ball circulation type linear bearing and the other end is supported by a slide bearing. 2. The slide bearing portion is configured so that a guide shaft arranged on the stator slides on a sliding surface of a substantially U-shape or a U-shape provided on the mover. Bearings for linear motors. 3. The bearing for a linear motor according to claim 2, wherein the guide shaft of the slide bearing portion is offset with respect to the guide direction of the ball circulation type linear bearing. 4. An armature in which four coils are arranged at substantially equal intervals corresponding to an electrical angle of 360 ° ± 60 °, and one end of each coil is commonly connected to each phase terminal, and a plate-shaped non-contact is provided. A plurality of plate-shaped permanent magnets are arranged and mounted for each of the holding frames provided at a plurality of locations on the magnetic body at substantially equal intervals to form the plate-shaped mover, and the mover is provided on one side or both sides of the mover. The movable magnet type linear motor according to claim 2, wherein the movable magnet type linear motor is slidably supported so as to face the armature. 5. A part of a steel plate forming the stator yoke is cut open, and the cut open parts are cut and raised to form a substantially U shape.
A bearing for a linear motor, comprising: the ball circulation type linear bearing that forms both side surfaces of a U-shaped or U-shaped outer portion.