JP5544538B2 - Embedded cylindrical linear motor - Google Patents

Description

  The present invention relates to a magnet-embedded cylindrical linear motor, and in particular, a magnetic ring and a ring magnet body are alternately provided on a mover, and the ring magnet body is composed of a plurality of ring magnets, so that the magnetic flux flowing through the cylindrical stator is increased. The purpose is to obtain a sine wave-like thrust improvement.

As this type of magnet-embedded cylindrical linear motor conventionally used, for example, a magnet-embedded cylindrical linear motor having a configuration using a magnet by the magnetizing method of FIG. 8 of Patent Document 1 is shown in FIG. Has been adopted.
That is, as shown in FIG. 5, a cylindrical stator 3 having a stator winding 2 made of, for example, a three-phase winding is provided on the inner wall 1 a of the long cylindrical case 1.

  In the gap 4 inside each stator winding 2 of the cylindrical stator 3, a longitudinal shaped movable element 5 is disposed so as to be able to reciprocate along the axial direction A, and on the outer periphery of the movable element 5. A large number of ring magnet bodies 6 are provided, and each ring magnet body 6 is magnetized in the radial magnetization direction magnetized in the radial direction as indicated by arrows, and the magnetization directions thereof are alternately different. The direction is set.

JP 2002-369492 A

Since the conventional magnet-embedded cylindrical linear motor is configured as described above, the following problems exist.
That is, as the magnetic flux flows from the ring magnet body 6 against the cylindrical stator 3 having a stator winding 2 of the magnetic circuit described above, as shown in Figure 3, the magnetic flux passing through the ring magnet 6, FIG. 5 since the line with the arrow, the magnetic flux flows in the cylindrical stator 3, magnetic flux flows into the interior of the movable element 5, not a sine wave of the normal, clean waveform, partially flux is small point is generated , Thrust ripple was occurring.
Therefore, the thrust density decreases in proportion to the miniaturization, and it has been difficult to obtain a small and high thrust type linear motor.

The magnet-embedded cylindrical linear motor according to the present invention includes a cylindrical stator provided on an inner wall of a cylindrical case, a large number of stator windings provided at predetermined intervals on the cylindrical stator, and the cylindrical fixed A mover provided in the inner space of the child so as to be axially movable; a magnetic ring and a ring magnet body provided alternately at predetermined intervals along the axial direction on the outer periphery of the mover; and the ring magnet body. Two ring magnets for constituting, the magnetization directions of the ring magnets are different from each other in the axial cross section of the ring magnet body, and the ring magnets are shifted by 45 degrees with respect to the radial magnetization direction. As a result, the magnetic flux flowing through the cylindrical stator hardly flows inside the mover, and no sine wave is generated without thrust ripple. The ring magnets are arranged in series with each other in the axial direction, and the magnetization directions of the ring magnets are deviated by 45 degrees with respect to the radial magnetization direction to form a V-shape. It is the composition which is.

Since the magnet-embedded cylindrical linear motor according to the present invention is configured as described above, the following effects can be obtained.
That is, a cylindrical stator provided on the inner wall of the cylindrical case, a large number of stator windings provided at predetermined intervals on the cylindrical stator, and an axial movement within the inner space of the cylindrical stator A movable element provided freely, a magnetic ring and a ring magnet body provided alternately at predetermined intervals along the axial direction on the outer periphery of the movable element, and two ring magnets for constituting the ring magnet body The magnetization direction of each ring magnet is different from each other in the axial cross section of the ring magnet body, and each ring magnet is deviated by 45 degrees with respect to the radial magnetization direction. The magnetic flux that flows through the armature hardly flows inside the mover and is formed in a sinusoidal shape without generating a thrust ripple. Flows evenly cylindrical stator, the interior of the movable element flux does not flow almost, by the magnetic flux decreases, generated thrust ripple without any, it is possible to obtain a stable high thrust was.
Further, the ring magnet is composed of two pieces arranged in series in the axial direction, and the magnetization direction of each ring magnet is deviated by 45 degrees with respect to the radial magnetization direction, thereby forcing the flow of magnetic flux. Therefore, it is possible to prevent the thrust ripple from occurring.

It is sectional drawing which shows the magnet embedded cylindrical linear motor by this invention. It is an expanded sectional view of the principal part of FIG. It is explanatory drawing which shows the flow of the magnetic flux of the conventional structure of FIG. It is explanatory drawing which shows the flow of the magnetic flux of this invention structure of FIG. It is sectional drawing which shows the conventional magnet embedded cylindrical linear motor.

  According to the present invention, a magnetic ring and a ring magnet body are alternately provided on the mover, and the ring magnet body is constituted by a plurality of ring magnets so that the magnetic flux flowing through the cylindrical stator is sinusoidal and the thrust is improved. An object of the present invention is to provide an embedded magnet type cylindrical linear motor.

A preferred embodiment of a magnet-embedded cylindrical linear motor according to the present invention will be described below with reference to the drawings.
Note that the same or equivalent parts as in the conventional example will be described using the same reference numerals.
In FIG. 1, what is indicated by reference numeral 1 is a longitudinal cylindrical case, and a cylindrical stator 3 having a stator winding 2 formed of, for example, a three-phase winding is provided on an inner wall 1a of the cylindrical case 1. Is provided.

In the gap 4 inside each stator winding 2 of the cylindrical stator 3, a longitudinal shaped movable element 5 is disposed so as to be able to reciprocate along the axial direction A, and on the outer periphery of the movable element 5. A large number of ring magnet bodies 6 are provided, and each ring magnet body 6 is composed of two first and second ring magnets 6a and 6b as shown in the enlarged view of FIG.

The magnetization directions of the first and second ring magnets 6a and 6b are different from each other as indicated by arrows, and the inner circumference side or the outer circumference side of the known radial magnetization direction 6A shown in FIG. The direction of magnetization is magnetized so that the magnetization direction is deviated by several tens of degrees, for example, 45 degrees. In the case of 45 degrees, the magnets are formed along the 45-degree radial magnetization directions 6aA and 6bA. 6a, the 45-degree radial magnetization direction 6aA per 6b, 6ba are the diagonal line as viewed in the axial direction cross-section, the direction is different alternately, and is configured such that the V-shape.
The ring magnet bodies 6 and the magnetic rings 10 are alternately provided at predetermined intervals on the outer periphery 5a of the movable element 5. The ring magnet bodies 6 are arranged on the outer periphery 5a. It is configured to be embedded in between.

The magnetization method of the first and second ring magnets 6a and 6b constituting the ring magnet bodies 6 in the 45 degree radial magnetization directions 6aA and 6bA (indicated by arrows in FIGS . 1 and 2 ) is, for example, as described above. This is possible by applying a known method such as the magnetization method disclosed in FIG. 2, FIG. 6, FIG. 7 and FIG.
The 45-degree radial magnetization directions 6aA and 6bA are 45-degree radial magnetization directions because the ring magnets 6a and 6b are deviated by 45 degrees from the radial direction when the ring magnets 6a and 6b are viewed in the longitudinal section, that is, the above-described axial section . The 45 degrees can be increased or decreased by 10 to 15 degrees.

Next, the operation will be described. First, in the case of cylindrical linear motors definitive in FIGS. 1 and 2, the ring magnet 6a constituting the respective ring magnet body 6, 6b is composed of a pair above the 45 degree radial magnetization direction 6aA, it is magnetized in 6bA Therefore, since the magnetization directions of the ring magnet bodies 6 are V-shaped and the magnetization directions thereof are different from each other, the magnetic fluxes in the ring magnet bodies 6, the cylindrical stator 3, and the movable element 5 when three-phase driving is performed. As shown in FIG. 6, since the flow is forcibly adjusted along the 45 degree radial magnetization directions 6aA and 6bA of the ring magnets 6a and 6b of the ring magnet bodies 6, a large amount of magnetic flux is generated. It flows evenly through the cylindrical stator 3 and is forced into a sine wave magnetic flux with a larger peak than before, almost no magnetic flux flows inside the mover 5, and the magnetic flux is small as in the conventional case. It no thrust ripple occurs in part I, it is possible to obtain a stable high thrust was than before.

  The magnet-embedded cylindrical linear motor according to the present invention can be used as a linear motion actuator for a small member in various small devices.

DESCRIPTION OF SYMBOLS 1 Cylindrical case 1a Inner wall 2 Stator winding 3 Cylindrical stator 4 Space | gap 5 Movable element 5a Outer periphery 6 Ring magnet body 6a 1st ring magnet 6b 2nd ring magnet 6aA 45 degree radial magnetization direction 6bA 45 degree radial magnetization direction A Axial direction 10 Magnetic ring

Claims (1)

A cylindrical stator (3) provided on the inner wall (1a) of the cylindrical case (1), and a large number of stator windings (2) provided at predetermined intervals on the cylindrical stator (3); A mover (5) provided in an axial direction (A) in the inner space (4) of the cylindrical stator (3) and an outer periphery (5a) of the mover (5) in the axial direction (A ) Magnetic rings (10) and ring magnet bodies (6) provided alternately at predetermined intervals along the ring) and two ring magnets (6a, 6b) for constituting the ring magnet body (6). Prepared,
The magnetization directions of the ring magnets (6a, 6b) are different from each other in the axial cross section of the ring magnet body (6), and the ring magnets (6a, 6b) are deviated by 45 degrees with respect to the radial magnetization direction. As a result, the magnetic flux flowing through the cylindrical stator (3) hardly flows inside the movable element (5), and the magnet is formed in a sinusoidal shape without generating a thrust ripple. In embedded cylindrical linear motors,
The ring magnets (6a, 6b) are arranged in series with each other in the axial direction (A), and the magnetization directions of the ring magnets (6a, 6b) are deviated from the radial magnetization direction by 45 degrees to form a V shape. An embedded magnet type cylindrical linear motor characterized by being formed.

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