Lubricating device for a linear guideway

A lubricating device for a linear guideway, used at either side of the slide block of a linear guideway, comprises: a housing, oil-containing member, magnets and metallic magnetic members. Using a magnetic force to push the oil-containing member against the rail, the magnetic force will not fatigue but will increase with the reduction in distance between the magnets and the metallic magnetic members, therefore, the oil-containing member can be kept in a good contact with the rolling passage of the rail, and the lubricating oil can be continuously transmitted from the oil-containing member to the surface of the rail, thus lubricating the linear guideway automatically without disassembling it.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a lubricating device for a linear guideway, and more particularly to a lubricating device for a linear guideway whose oil-containing member can maintain an all-the-time effective contact with the rail even after wear and tear.

2. Description of the Prior Art

With the development of science and technology, and the improvement of the precision feeding system, linear guideway and technology thereof have become a most important part of many precision mechanisms. Various types of linear mechanisms have been and are being widely used in different fields. Although the linear guideway technology is developing fast, still there are some problems of the linear products that need to be improved. Many efforts have been made by the related industry to effectively improve the quality of linear guideway, in particularly, those high precision mechanisms (such as wafer processing equipment and CNC Computer Numeric Control instruments) that need to run stably and silently. Therefore, there are still some blind spots in the existing linear mechanisms that need to be exploited and erased.

Most of the existing linear guideways are provided at both sides of the slide block thereof with oil tanks in which is received an oil-containing sponge. The oil-containing sponge will wear out after long time of use, so that a clearance will appear between the sponge and the rail of the linear guideway, and it will prevent the lubricating oil from reaching the linear guideway. Therefore, many linear products have been developed to solve this problem, they generally includes the following three types:

First, arranging a spring in the oil tanks and using it to push the oil-containing sponge against the rail, but the shortcoming is too complicated in structure and not easy for assembly. In addition, the spring will become loose with the wear of the oil-containing sponge and also because of the elastic fatigue of the spring itself (such as the device of U.S. Pat. No. 5,547,285).

Second, arranging a reverse U-shaped elastic piece in the oil tanks and using it to push the oil-containing sponge against the rail, but the shortcoming is, like the previous one, that the spring will become loose with the wear of the oil-containing sponge and also because of the elastic fatigue of the spring itself (such as the device of U.S. Pat. No. 6,672,764).

Third, arranging an elastic rubber in the oil tanks and using it to push the oil-containing sponge against the rail, but it still has the same shortcoming as the previous two.

SUMMARY OF THE INVENTION

The primary objective of the present invention is to provide a lubricating device for a linear guideway whose oil-containing member can maintain an effective contact with the rail even after wear and tear. The present invention uses a magnetic force to push the oil-containing member against the rail, the magnetic force will not fatigue but will increase with the reduction in distance between the magnets and the metallic magnetic members, therefore, the oil-containing member can be all-the-time kept in a good contact with the rolling passage of the rail.

The secondary objective of the present invention is to provide a lubricating device for a linear guideway that have simple structure and can be assembled easily and only consists of housing, oil-containing member and magnets.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring toFIGS. 1 and 2, a linear guideway in accordance with a first embodiment of the present invention includes a slide block1, a rail2with a rolling passage21, a pair of end caps3, a pair of oil scrapers4, and two lubricating devices5.

Each of the lubricating device5is fixed between the end cap3and the oil scraper4at either side of the slide block1, and comprises a housing6, an oil-containing member7, a pair of magnets8, a pair of metallic magnetic members9and a cover10.

The housing6cooperate with the cover10to define an assembly space61. On a lateral surface of the housing6is defined an oil feeding hole63, the assembly space61has a notch64formed correspondingly to the rail2, and in the assembly space61are arranged a pair of positioning protrusions65that each has a groove62facing the rail2. The grooves62are opposite each other and located a certain distance away from the inner wall of the assembly space61.

The oil-containing member7is a sponge received in the assembly space61and is formed with a pair of grooves72for mating with the grooves62of the positioning protrusions65. A pair of inwardly extending protrusions71formed on the oil-containing member7extends into the notch64of the assembly space61and comes into effective contact with the rolling passage21of the rail2. Outside the grooves72are formed a pair of recesses73that face the inner wall of the assembly space61.

The magnets8are received in the grooves62of the positioning protrusions65.

The metallic magnetic members9are received in the recesses73at both lateral surfaces of the oil-containing member7and are attracted by the magnets8in the grooves62.

For a better understanding of the present invention, its operations and functions, references should be made toFIGS. 3 and 4. The magnets8will generate a magnetic force to the metallic magnetic members9in the recesses73at both lateral surfaces of the oil-containing member7, pulling the metallic magnetic members9toward the rolling passage21of the rail2. Consequently, the metallic magnetic members9will push the oil-containing member7against the rail2, enabling the protrusions71of the oil-containing member7always to come into an effective contact with the rolling passage21of the rail2without being affected by the wear of the oil-containing member7. The magnetic force between the magnets8and the metallic magnetic members9will not fatigue but will increase since the distance between the magnets8and the metallic magnetic members9will be reduced with the wear of the oil-containing member7, therefore, the oil-containing member7can be all-the-time kept in a good contact with the rolling passage21of the rail2.

The cover10will be covered on the longitudinal mouth of the housing6relative to the rail2.

The oil-containing member7can be made of porous material, such as wool felt and foam material. The oil-feeding hole63of the lubricating device5can be sealed with plastic material66, and a needle or oil nozzle67can be used to feed oil into the oil-feeding hole63by puncturing the plastic material directly.

Referring toFIGS. 5 and 6, which show another embodiment of the present invention, wherein the metallic magnetic members9is replaced by the metal rail2, and the magnets8are received in a deep recess74at either lateral surface of the oil-containing member7. The recesses74are deep and located close to the metal rail2such that the magnets8can generate a magnetic force directly to the rail2for pushing the oil-containing member7. The grooves62of the positioning protrusions65can limit the displacement of the magnets8. This embodiment has the same function as the first embodiment but is simpler in structure.