JPH03215159A - Tubular linear pulse motor - Google Patents

Abstract

PURPOSE:To dispense with a linear bearing, which holds the main shaft holding a mover, by installing a tubular mover, where permanent magnets are fixed to the inside, on a columnar stator, where exciting windings are wound on the periphery, freely in sliding. CONSTITUTION:A columnar stator 50 is composed of a yoke 52 made of magnetic material, an exciting winding 54 set in the circular groove formed in the yoke 52, a cover 56 of nonmagnetic substance, and a plug 58. A mover 60 has a cylinder frame of magnetic substance, a permanent magnet 64 fixed to the inside periphery, and guide members 66 fixed to both ends of the frame 62. To the inside periphery of the guide member 66 is applied coating of fleon resin so as to decrease the sliding resistance with the cover 56. The outside periphery of the cover 56 is coated with fleon resin after applying electrolytic plating so as to decrease sliding resistance.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention provides a cylindrical mover in which a cylindrical mover to which a permanent magnet is fixed moves outside a stator to which an excitation winding is attached. It is about Linyabal smoke.

(Background of the Invention) As this type of linyabalusmotor, the one shown in FIG. 2 is known. In FIG. 2, reference numeral 10 denotes a cylindrical moving element, which is fixed to a non-magnetic main shaft 12. As shown in FIG. The slider 10 is made of magnetically permeable material such as iron, and has an annular permanent magnet 14 (14a-
d) are fixed at predetermined intervals. Each permanent magnet 1
4 is magnetized in the radial direction and has different polarities on its inner and outer circumferential sides. A cylindrical stator 16 covers the outside of the movable range of the mover 10.

Annular grooves (slots) 18 perpendicular to the central axis of the stator 16 are formed at regular intervals on the inner circumferential surface of the stator 16, and an excitation winding 20 is loaded into each slot 18. These excitation windings 2o are selectively excited in a predetermined order, and each groove 18
The salient pole 22 in between is N. It is magnetized to S pole or non-polar.

In a conventional pulse motor having such a structure, the mover 10
It is necessary to support the main shaft 12 to which the main shaft 12 is fixed so that it can reciprocate by a linear bearing (not shown). Further, it is necessary to leave space for the movement range of the main shaft 12. For this reason, there was a problem that the structure was complicated and increased in size.

On the other hand, when using this conventional pulse motor to linearly drive a driven object (driven member) such as a printer head or an industrial robot, the driven object is slidably held on a guide race, etc. It becomes necessary to convey the movement of the pulse movable element to the pulse motor. For this reason, when used in an actual device, there is a problem that the number of parts increases, making it even more difficult to miniaturize the device.

(Object of the Invention) The present invention was made in view of the above circumstances, and it provides a cylinder that has a simple structure and is suitable for miniaturization, does not require an increase in the number of parts when incorporated into a device, and is suitable for miniaturization of the entire device. The purpose is to provide a type linear pulse motor.

(Structure of the Invention) According to the present invention, the purpose is to provide a mover to which permanent magnets with alternating polarities are attached along the direction of movement, and a stationary member to which a large number of excitation windings are attached opposite to these permanent magnets. In the cylindrical linear smoke, the stator has a cylindrical shape with an excitation winding wound around the outer periphery, the mover has a cylindrical shape with a permanent magnet fixed on the inner periphery, and the stator and the mover This is achieved by a cylindrical linear pulse motor characterized by interposing a sliding material between the contact surfaces with the cylindrical linear pulse motor.

(Example) FIG. 1 is a sectional view of an embodiment of the present invention.

In this figure, reference numeral 50 denotes a cylindrical stator, which includes a yoke 52 made of a material that passes magnetic flux, such as iron, and excitation windings loaded into annular grooves formed at regular intervals in this yoke 52. 54, a cover 56 made of a non-magnetic material such as a stainless steel plate that covers the outside of the yoke 52, and plugs 58, 58 made of a non-magnetic aluminum material fitted into both ends of the cover 56. It is something. It is desirable that the outer peripheral surface of the cover 56 be electrolytically nickel plated and then coated with a fluorocarbon resin to reduce sliding frictional resistance.

Reference numeral 60 denotes a mover, which includes a frame 62 made of a material such as iron that passes magnetic flux in a cylindrical shape, annular permanent magnets 64 fixed at predetermined intervals on the inner peripheral surface of the frame 62, and It has annular guide members 66, 66 made of aluminum fixed to both ends. The inner diameter of the guide member 66 is slightly larger than the outer diameter of the stator 50, that is, the outer diameter of the cover 56, and its inner peripheral surface is coated with fluorocarbon resin to reduce sliding resistance with the cover 56. There is.

The inner diameter of the permanent magnet 64 is made slightly larger than the inner diameter of the guide member 66 so that the permanent magnet 64 does not come into direct contact with the canopy 56 when the mover 60 slides on the outer circumference of the stator 50. There is.

Both ends of the stator 50 are equipped with a device using this pulse motor,
For example, it is fixed to a frame such as a printer. Mover 6
0 is mounted on this stator 50, and an object to be driven, such as a print head of a printer, is fixed to this mover 60. Note that for a driven object such as a print head whose rotation around the stator 50 needs to be restricted, another guide rail (not shown) is provided in parallel with the stator 50.
The object to be driven may be held between a member that slides on the guide rail and the movable element 60. Further, protrusions or grooves parallel to the length direction of the stator 50 are formed, and grooves or protrusions that engage with these protrusions or grooves are formed on the movable element 60 side to prevent rotation of the slider. You may also try to prevent it.

The excitation winding 54 of the stator 50 is operated using a one-phase two-pole excitation method in which an excitation current is passed through only one of the adjacent phases A and B, and a two-phase excitation method in which the excitation winding is operated while always exciting two phases. Excitation is performed by various methods, such as an excitation method called a half-step drive or a 1-2 phase excitation method, which is an intermediate method between these one-phase excitation and two-phase excitation. Here 1-2
In the phase excitation method, it is also possible to use a microstep drive method in which the input pulse is made finer and the input signal is made into a sinusoidal waveform.

Furthermore, it is desirable that the stator of the present invention has a circular cross section;
This may have a polygonal cross-sectional shape, and the inner surface of the mover may have a corresponding polygonal shape.

In this embodiment, a sliding material formed of a cylindrical cover 56 made of stainless steel is used, but the sliding material of the present invention is not limited to this. It may be formed with a cover. This sliding material is not limited to metal such as stainless steel, but may also be a resin tube or cover.

Furthermore, these surfaces may be coated or applied with a material rich in lubricity.

(Effects of the Invention) As described above, the present invention includes a columnar stator having an excitation winding wound around its outer periphery, and a cylindrical mover having a permanent magnet fixed to its inner surface slidably mounted thereon. Since a sliding material is interposed between the contact surfaces of the stator and the movable element, the movable element itself can be held on the stator while sliding. Therefore, there is no need for a linear bearing that movably holds the main shaft that holds the slider, which was necessary in the conventional device, and it is also no longer necessary to leave a space in the movement range of this main shaft.

In addition, by fixing the driven object to this mover, the stator can be used as a guide rail for the driven object, so there is no need for a dedicated guide rail to hold the driven object movably. The number of guide rails can be reduced.

Therefore, when incorporated into a device, the number of parts can be reduced, making it possible to downsize the entire device.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the present invention, and FIG. 2 is a sectional view of a conventional device. 50... Stator 54... Excitation winding, 56... Sliding material, 60... Mover, 64... Permanent magnet.

Claims (7)

[Claims] (1) In a cylindrical linear pulse motor that has a mover to which permanent magnets with alternating polarities are attached along the direction of movement, and a stator to which a large number of excitation windings facing these permanent magnets are attached, The stator has a columnar shape with an excitation winding wound around the outer periphery, the movable element has a cylindrical shape with a permanent magnet fixed to the inner periphery, and a sliding material is interposed between the contact surfaces of the stator and the movable element. A cylindrical linear pulse motor characterized by: (2) The cylindrical linear pulse motor according to claim (1), wherein the stator has a circular cross section and the mover has a cylindrical shape. (3) The cylindrical linear pulse motor according to claim 1, wherein the sliding member is a cylinder made of a non-magnetic metal thin plate that covers the outer peripheral surface of the solid element. (4) The cylindrical linear pulse motor according to claim 3, wherein a Teflon coating layer is formed on the outer peripheral surface of the cylinder of the sliding material. (5) The cylindrical linear pulse motor according to claim (1), wherein the outer peripheral surface of the stator is coated with resin. (6) Claim (3) wherein a coating layer of a ceramic layer is formed by plasma spraying on the outer peripheral surface of the cylinder of the sliding material.
) Cylindrical linear pulse motor described in ). (7) The cylindrical linear pulse motor according to claim 3, wherein a coating layer of a composite ceramic based on chromium oxide is formed on the outer peripheral surface of the cylinder of the sliding material.