JPS5814698Y2 - Reciprocating drive device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for reciprocating a movable element formed by a permanent magnet within a stator coil, and more particularly to a reciprocating drive device with improved sliding parts and improved wear resistance.

Conventionally, there is a device that uses a combination of an electromagnetic coil and a permanent magnet to drive one of them back and forth as a movable element, but there are a relatively large number of devices that use an electromagnetic coil as a movable element.

However, this type of reciprocating drive device has drawbacks such as a complicated configuration of the power feeding section, a limited capacity because the magnetic circuit gap length cannot be increased, and poor durability.

For this reason, reciprocating drive devices that use permanent magnets as movers are increasingly attracting attention.

In this case, the mover is generally slidably engaged with the stator via a shaft and a bearing, but when driving a device such as a pump, scattering of lubricating oil is a serious drawback. Oil-impregnated or lubricated high-performance bearings cannot be used in the bearing part.

Therefore, it is necessary to use a non-lubricated type bearing, which has drawbacks such as short life due to wear and complicated maintenance and inspection.

The object of the present invention is to eliminate the above-mentioned drawbacks and provide a reciprocating drive device that has a long life and is easy to maintain and inspect.

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

In the figure, reference numeral 1 denotes a yoke, which is formed of a ferromagnetic material into a hollow shape with an approximately E-shaped end face in longitudinal section.

Next, 2 is a coil to which electromagnetic action is to be applied, and yoke 1
It is arranged so that the same polarity occurs in adjacent parts within the terminal, and electrically connected to an external power supply.

A movable element 3 is provided in the hollow part of the yoke 1 so as to be slidable in the axial direction, and a shaft 4 is provided to protrude through the end of the yoke 1.

The mover 3 is formed by fixing magnetic pole pieces 6 to both ends of a permanent magnet 5 which is magnetized so that N and S poles appear in the axial direction.

Next, a sliding member 7 is provided between the magnetic pole piece 6 and the inner surface of the yoke 1 to support the movable element 3.

The sliding member 7 is made of, for example, a non-magnetic material, and is fixed to either the yoke 1 or the movable element 3, and is attached to the movable element 3.
be slidable.

Therefore, the sliding member 7 does not necessarily need to be in full contact with the movable member 3, and may be formed into, for example, arcuate segments and arranged at intervals.

Next, 8 is an oil seal, which allows the shaft 4 to freely slide and maintains the inside of the yoke 1 and the outside world airtight.

With the above configuration, when an alternating current or a pulse current is supplied to the coil 2, the movable element 3 reciprocates in the axial direction due to the electrode attraction and repulsion action with the permanent magnet 5 forming the movable element 3.

In this case, since the movable element 3 is supported by the sliding member 7 and reciprocates with the presence of lubricant, extremely smooth reciprocation is possible.

Note that since the lubricant remains within the yoke 1 by the oil seal 8, it is prevented from escaping or scattering to the outside of the device.

FIG. 2 is a longitudinal sectional view showing another embodiment of the present invention, in which a sliding member 7a is interposed on the outer periphery of the permanent magnet 5.

In this case as well, the sliding member 7a can be fixed to either the yoke 1 or the mover 3, and the operation is the same as in the previous embodiment.

In addition, in FIG. 2, when the inner diameter of the sliding portion of the sliding member 7a is d and the relationship with the outer diameter of the mover is d<D, it is particularly effective magnetically.

In other words, it is generally preferable for the permanent magnet 5 to be magnetized while being incorporated into the yoke 1, but even if it is so-called built-in magnetized, it may be difficult to perform inspection, repair, parts replacement, etc. In this case, when the permanent magnet is taken out of the yoke, the characteristics deteriorate significantly.

Therefore, in order to maintain the characteristics during use, it is preferable that the permanent magnet 5 always remain within the yoke 1.

In this regard, among the devices shown in FIG. 2, in the case where the dimensional relationship is d<D, even if the end plate of the yoke 1 is removed, for example when replacing the oil seal 8, the mover 3 remains inside the yoke 1. Therefore, deterioration of characteristics due to removal of the magnet can be prevented.

Note that the sliding member 7a is provided at the end of the movable element 3, and the above-mentioned d<
Even if the dimensional relationship D is set, the effect of preventing deterioration of the magnetic properties is the same.

In this embodiment, an example of a sliding member made of a non-magnetic material is shown, but for example, in the case where the sliding member is provided at the end of the mover, the distance from the yoke or the magnetic pole portion of the mover may be If the movable element is sufficiently provided, even if the movable element is made of ferromagnetic material, it is possible to prevent an accident in which the movable element is attracted to the stator and the reciprocating movement of the movable element becomes impossible.

Since the reciprocating drive device of the present invention has the structure and operation as described above, it can achieve the following effects.

(1) Since a wear-resistant material can act as a sliding member between the mover and the stator, continuous operation for a long time is possible and maintenance and inspection are easy.

(2) Since the sliding portion is inside the stator, scattering of the lubricant can be prevented by using an appropriate sealing means.

(3) The sliding parts of the movable element and the stator can be made highly accurate, and the accuracy can be maintained for a long period of time.

(4) By setting the dimension between the sliding part inner diameter d and the mover outer diameter to be d<D, deterioration of magnetic properties can be prevented.

(5) Since the shaft to be connected to the driven device does not need to support the mover, the diameter can be reduced.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are longitudinal sectional views each showing an embodiment of the present invention. 1: Yoke, 2: Coil, 3: Mover, 7, 7a: Sliding member.

Claims (1)

[Scope of utility model registration request] 1. Two cylindrical electromagnetic coils are arranged in a yoke made of a ferromagnetic material whose longitudinal cross-sectional end face in a plane including the axis is formed into a substantially E shape, so that the same polarity occurs in adjacent parts, and the yoke center A permanent magnet having a magnetic pole piece at the shaft end and magnetized in the axial direction is provided in the part so as to be slidable in the axial direction to form a mover, and the permanent magnet is slidably attached to at least one of the yoke or the mover. A reciprocating drive device characterized in that the members are fixed and the inner surface of the yoke and a part of the outer circumferential surface of the movable element are brought into contact engagement through the sliding member. 2. The reciprocating drive device according to claim 1, wherein the sliding member is made of a non-magnetic material. 3. The reciprocating drive device according to claim 1 or 2, in which a sliding member is provided protrudingly from the end of the movable element, and the relationship d<D is satisfied. However, d: Inner diameter of sliding part D: Outer diameter of mover