JP2010035296A - Magnet skew structure for cylindrical linear motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the connecting condition in each magnetic piece on a movable shaft side into a skew state to attain an improvement in torque and a reduction in cogging, when using a stator core on a stator side. <P>SOLUTION: In the magnet skew structure for a cylindrical linear motor, the connecting surface (7) of each magnetic piece (6) provided on the peripheral surface (5a) of the movable shaft (5) is non-parallel with the radius direction orthogonal to the shaft direction of the movable shaft (5), so that the magnetic pieces (6) are arranged in a magnet skew (10) state. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnet skew structure of a cylindrical linear motor, and in particular, when a stator core is used on the stator side, the connection state of each magnet piece on the movable shaft side is set to a magnet skew state, thereby improving torque and reducing cogging. It relates to a new improvement for achieving the above.

  Conventionally used linear motors of this type can include, for example, configurations shown in Patent Documents 1 and 2, but these linear motors have permanent magnets on the stator side and coils on the movable side. Although only the yoke, the structure of each magnet piece provided on the movable shaft of the cylindrical linear motor is generally configured as shown in FIG.

  That is, what is denoted by reference numeral 1 in FIG. 2 is a cylindrical casing. A large number of stator coils 3 having a stator core 2 are arranged on the inner wall 1a of the casing 1, and the stator cores 2 are arranged at predetermined intervals. It is installed.

  Between the pair of first and second bearings 4, 4 a provided at both ends of the casing 1, a movable shaft 5 provided in the casing 1 is arranged so as to be capable of reciprocating linearly along the direction of arrow A. It is installed.

  A large number of magnet pieces 6 are provided along the axial direction on the peripheral surface 5 a of the movable shaft 5, and the surface direction of the connecting surface 7 of each magnet piece 6 is a radius orthogonal to the axial direction of the movable shaft 5. It matches the direction. That is, it is a non-magnet skew state.

  In the above-described configuration, by supplying a predetermined drive pulse to the stator coil 3 provided in each stator core 2, step drive and continuous drive are performed by a known magnetic action with each magnet piece 6 on the movable shaft 5. It can be performed.

JP 2006-28458 A JP 2006-28462 A

Since the conventional cylindrical linear motor is configured as described above, the following problems exist.
That is, in general, the cylindrical linear motor has a coreless configuration on the casing side, but in order to increase torque, the core is used as in the configuration of FIG. Since no skew was applied, the cogging torque was large and the operation during linear movement was not smooth.

  The magnet skew structure of the cylindrical linear motor according to the present invention includes a stator core provided at a predetermined interval on the inner wall of an inner cylindrical casing, a stator coil provided on each stator core, and first stator coils provided at both ends of the casing. 1, a second bearing, a movable shaft provided in the casing so as to be able to reciprocate linearly through the bearings, and a plurality of magnet pieces provided on the peripheral surface of the movable shaft and alternately serving as different magnetic poles, The connection direction of the connection surface of each magnet piece is in a non-parallel state with respect to the radial direction orthogonal to the axial direction of the movable shaft, and each magnet piece is arranged in a magnet skew state. In addition, the cross-sectional shape of each magnet piece is a rhombus.

Since the magnet skew structure of the cylindrical linear motor according to the present invention is configured as described above, the following effects can be obtained.
That is, a stator core provided at predetermined intervals on the inner wall of the inner cylindrical casing, a stator coil provided in each stator core, first and second bearings provided at both ends of the casing, and the casing A movable shaft provided so as to be capable of reciprocating linearly through the bearings, and a plurality of magnet pieces provided on the peripheral surface of the movable shaft and having different magnetic poles alternately. The connecting direction is not parallel to the radial direction orthogonal to the axial direction of the movable shaft, and the magnet pieces are arranged in a magnet skew state, so that the gogging torque is reduced despite the torque increase. Generation can be suppressed and smooth linear motion can be obtained. Further, since the cross-sectional shape of each magnet piece is a rhombus, the magnet pieces can be easily stacked on the movable shaft.

  In the present invention, when a stator core is used on the stator side, a magnet of a cylindrical linear motor that achieves torque improvement and cogging reduction by setting the connection state of each magnet piece on the moving shaft side to a magnet skew state. An object is to provide a skew structure.

A preferred embodiment of a magnet skew structure of a cylindrical linear motor according to the present invention will be described below with reference to the drawings.
In addition, the same code | symbol is attached | subjected and demonstrated to a part the same as that of a prior art example, or an equivalent part.
1 is a cylindrical casing. A large number of stator coils 3 having a stator core 2 are arranged on the inner wall 1a of the casing 1, and the stator cores 2 are arranged at predetermined intervals. Has been.

  Between the pair of first and second bearings 4, 4 a provided at both ends of the casing 1, a movable shaft 5 provided in the casing 1 is arranged so as to be capable of reciprocating linearly along the direction of arrow A. It is installed.

  A large number of magnet pieces 6 are provided along the axial direction on the peripheral surface 5 a of the movable shaft 5, and the connection direction of the connection surfaces 7 of the magnet pieces 6 is a radius orthogonal to the axial direction of the movable shaft 5. The state is inclined in a non-parallel state with respect to the direction, that is, a magnet skew state in which a known skew is applied.

  Accordingly, because the magnet pieces 6 having different polarities are diamond-shaped in cross-section due to the state of the known magnet skew 10 of the magnet pieces 6 according to the arrangement of FIG. 1, the magnet pieces 6 are in the axial direction of the movable shaft 5. The ends of the magnet pieces 6 are superposed with each other in the orthogonal radial direction, and the state of change in polarity between the magnet pieces 6 is not abrupt, which is more gradual than the sudden polarity switching of the magnet pieces 6 in FIG. Smooth magnetic action can be obtained.

  In the above-described configuration, by supplying a predetermined drive pulse to the stator coil 8 provided in each stator core 2, step drive and continuous drive are performed by a known magnetic action with each magnet piece 6 on the movable shaft 5. It can be performed.

It is sectional drawing which shows the magnet skew structure of the cylindrical linear motor by this invention. It is sectional drawing which shows a conventional structure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Casing 1a Inner wall 2 Stator core 3 Stator coils 4, 4a 1st, 2nd bearing 5 Movable shaft 5a Circumferential surface 6 Magnet piece 7 Connection surface 10 Magnet skew

Claims (2)

A stator core (2) provided at predetermined intervals on the inner wall (1a) of the inner cylindrical casing (1), a stator coil (3) provided on each stator core (2), and both ends of the casing (1) First and second bearings (4, 4a) provided on the casing, and a movable shaft (5) provided in the casing (1) so as to be capable of reciprocating linearly through the bearings (4, 4a), A number of magnet pieces (6) provided on the peripheral surface (5a) of the movable shaft (5) and alternately different magnetic poles,
The connection direction of the connection surface (7) of each magnet piece (6) is in a non-parallel state with respect to the radial direction perpendicular to the axial direction of the movable shaft (5), and each magnet piece (6) is magnet skew. A magnet skew structure for a cylindrical linear motor, characterized in that the magnet skew structure is disposed in the state of (10).   2. The magnet skew structure of a cylindrical linear motor according to claim 1, wherein the cross-sectional shape of each of the magnet pieces (6) is a rhombus.

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