JPH0627344Y2 - Dust protection device for linear motor driveways - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a linear motor, and more specifically, in a linear motor that conveys a load, its travel path is protected from dust or other fine powder, or foreign matter such as gas. The present invention relates to a dustproof device for protection.

[Prior Art] Linear motors are roughly classified into linear DC motors (LDM), linear induction motors (LIM), and linear pulse motors (LPM), depending on the type of thrust. , Linear synchronous motors, MHD pumps and the like.

Depending on the location where these linear motors are used, ingress of dust or other foreign matter, especially organic fine particles or magnetic iron powder, may hinder the running of the linear motor or may adversely affect the movable and fixed parts. .

A linear pulse motor will be described as an example of means for preventing the intrusion of such dust and other foreign matter. Conventionally, as shown in FIG. 2, one end portion (the left end in the figure) of the traveling path 11 of the linear motor is conventionally used. Between one end (the left end in the figure) of the movable part 10 and the other end (the right end in the figure) of the traveling path 11 and the other end (the right end in the figure) of the movable part. ,
A bellows-shaped stretchable covering member, that is, a bellows-like covering member 18 and 18 'are connected to form a ceiling and a side wall of a protective space, and a movable part is covered so as to expand and contract like an accordion curtain. It was designed to protect against the intrusion of dust and other foreign matter.

[Problems to be Solved by the Invention] However, no matter what material is used, when formed into a bellows shape, it constitutes a kind of spring.

In FIG. 2, the movable portion is 10, the midpoint of the traveling path is M,
If the protective bellows on the left side of the movable part is 18 and the protective bellows on the right side of the movable part 10 is 18 ', the protective bellows 18 and 18' are free heights when the movable part 10 is at the midpoint M of the traveling path. It is set so as to be balanced in an unloaded state at a height h.

In this state, the movable part 10 is not restrained by the protective bellows 18 and 18 'on both sides.

However, when the movable part 10 receives a thrust and tries to travel to the left, the movable part 10 must compress the protective bellows 18 and pull the protective bellows 18 'to travel.

The thrust force added to supplement the original thrust force in order to cause the movable portion 10 to travel against such compression and tensile forces is the extent of deformation of the protective bellows 18 and 18 ′, that is, the movable thrust force. It increases as the part 10 moves away from the intermediate point M toward the end of the road. However, when the movable part 10 returns from the end of the traveling path to the intermediate point M, it is a fact that the energy stored in the protective bellows, which is a kind of spring, can be used, but the protective bellows 18 and 18 ' With the provision of the above, it is indispensable to increase the required thrust in the stroke from the intermediate point M toward the end of the traveling road, which causes a loss of the thrust. In order to compensate for this, it is necessary to increase the size of the linear motor, or to increase the magnetic force by changing the configuration of the magnetic circuit or the magnetic material, or to adopt both of them, resulting in an increase in production cost. Will be done.

By selecting the type and thickness of the material of the protective bellows, it is possible to set the degree of increase in the required thrust to a value that is somewhat lower than the original thrust for moving the movable portion 10. Effective measures have been demanded from the viewpoints of downsizing of linear motors and reduction of production costs.

[Means for Solving the Problems] In solving the problems described above, the present invention is directed to a linear motor conveyance device, which is resistant to protective bellows arranged on both left and right sides of a movable portion as in the prior art. An object of the present invention is to provide a device capable of performing a dustproof function without relying on a means for enlarging a linear motor or increasing a magnetic force to pull and move a movable part. As a solution to meet this purpose, a pair of constant tension springs that apply tensile forces to opposite sides of the moving portion of a linear motor that travels horizontally from opposite sides along the direction of travel movement are provided. This is solved by causing the leaf spring itself, which constitutes the constant tension spring, to function as the ceiling of the dustproof device.

[Operation] The constant tension spring is constructed so that when a spring material such as a spiral spring is extended from the fixed core portion, a constant tension is always applied to the action point regardless of the length of the extension. , The moving part of the linear motor is maintained in an equilibrium state by canceling the tension in the opposite direction exerted by the two constant tension springs, regardless of the position on the traveling path, and the moving part of the system including the protecting device is kept. It is only necessary to consider its own weight and frictional resistance.

[Embodiment] A preferred embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 (A) is a schematic side view showing an embodiment of the present invention,
FIG. 1 (B) is the same perspective view, and FIG. 1 (C) is a partially enlarged perspective view of the right end portion.

Reference numeral 10 in the drawing denotes a movable portion of the linear motor, which is a fixed portion 1.
A roller 15 for causing the movable portion 10 to smoothly travel with respect to the secondary side of the near motor, that is, the fixed portion 11, is provided on the bottom portion in contact with 1.

The fixed portion 11 is composed of a permanent magnet and iron in a linear DC motor (LDM), aluminum and iron in a linear induction motor (LIM), and a comb-shaped magnetic material called a scale in a linear pulse motor (LPM).

Reference numerals 12 and 12 'denote fixed cores 14 and 14' and spring members 13 and 13 'such as spiral springs wound around them.
In the constant tension winding spring, the left fixed core 14 is mounted on the secondary side of the linear motor, that is, the upper surface of the fixed portion 11, and the tip end extended from the fixed core 14 is attached to the movable portion 10 of the linear motor. Be connected.

When the movable part 10 travels on the upper surface of the fixed part 11 provided horizontally, the tensions of the constant tension take-up springs applied to the front and rear of the traveling direction of the movable part 10, that is, the left and right sides in the figure are set to be the same. If so, the movable portion 10 is always kept in a balanced state by the tension of the springs applied to the left and right sides.

In this state, the upper surface of the movable portion 10 and the spring members 13 and 13 'of the constant tension winding springs 12 and 12', respectively.
And form a ceiling that covers the linear motor conveyance device.

As shown in FIG. 1 (C), left and right fixed cores 14 and 14 '.
By providing the side covers 16 that cover both ends in the longitudinal direction, the side surfaces of the movable portion 10 and the fixed portion 11, an outer wall that surrounds the linear motor transport device is defined. Therefore, the side cover 1 that contacts the side edges 17 of the spring members 13 and 13 '.
If a sealing mechanism using a velvet woven fiber material is provided on the inner surface of 6, the spring members 13 and
3'and the side cover 16 are relatively movable,
Moreover, a dustproof device is formed to prevent dust and metal powder from entering the inside of the linear motor carrying device surrounded by the outer wall. The sealing material and structure forming this sealing mechanism may be selected according to the type and size of dust, gas, etc. to be protected against dust. Since such a sealing mechanism itself is not the object of the present invention, further description will be omitted.

[Effect] Since such a constant tension take-up spring generally has a simple structure, the total weight including the dustproof device can be made extremely lighter than that of the prior art.

Further, the take-up spring fed from the fixed core 14 is irrespective of the feeding length, that is, the position occupied by the movable portion 10 on the fixed portion 11, from both left and right sides with respect to the movable portion 10.
The thrust force required for the transport device can be balanced by applying tensile forces of opposite directions and of constant magnitude.
Since it is only necessary to consider the weight of the movable part 10, the weight of the load to be transported, the frictional resistance in the seal mechanism and other parts, the load can be reduced with a considerably smaller thrust than the conventional dustproof device using the bellows. It becomes possible to carry.

[Brief description of drawings]

1 (A) is a schematic side view showing a preferred embodiment of the present invention, FIG. 1 (B) is a perspective view of FIG. 1 (A), and FIG. 1 (C) is FIG. 1 (B). ) Is a partially enlarged perspective view, and FIG. 2 (A) is a schematic side view of a conventional dustproof device,
FIG. 2B is a perspective view of FIG. 2A. Reference numeral 10 in the drawings: 10: movable part of linear motor, 11: fixed part of linear motor, 12, 12 ': constant tension winding spring, 13, 13': spring member, 14, 14 ': fixed core 15, 15' : Roller, 16: side cover, 17: side edge of spring member.

Claims (2)

[Scope of utility model registration request] 1. A running path of a linear motor carrying device, comprising: a fixed part having a running path; and a movable part which is located on the fixed part and moves along the running path to carry a load. In the dustproof device, the dustproof device includes a pair of fixed cores mounted on the fixed part at one end and the other end in the moving direction of the movable part, respectively.
A pair of constant tension take-up spring members that are extended from each of the fixed cores toward the inside of the traveling path, and the ends of the fixed cores are connected to the facing portions of the movable portion on the traveling path. , Each of which has a pair of constant tension take-up spring members that apply tensions of the same magnitude and opposite directions to the movable portion, and the movable portion and the pair of constant tensions connected to both ends thereof. The winding spring member constitutes a ceiling of the dustproof device for the traveling path of the linear motor, and the movable portion is moved by the same thrust regardless of the position on the traveling path. Dustproof device for motor running path. 2. The fixed portion of the linear motor is provided with a side cover that surrounds side surfaces of the fixed portion and the movable portion,
The side edge of the dustproof device in the transverse direction of the ceiling and the inner circumference of the side cover are made of a fibrous woven fabric having a short and dense pile such as velvet, and can be relatively moved through a sealing material that prevents foreign matter from entering from the outside world. The dustproof device for a linear motor traveling path according to claim 1, wherein