Lubricating device for linear transmission mechanism

A lubricating device used in a linear transmission mechanism is disclosed to include a housing having an accommodation chamber and an opening formed on the inside and periphery thereof in equal cross section, a pressure member axially movable in the accommodation chamber, a screw rod pivotally mounted in the housing and having a first transmission portion located on one end thereof and extended out of the pressure member, a screw nut threaded onto the screw rod and driven by the screw rod to stop against the pressure member outside, a transmission member defining therein a transmission slot and a second transmission portion and a third transmission portion at two opposite sides of the transmission slot for alternatively rotating the first transmission portion, and driving device for reciprocating the transmission member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to lubricating technology and more particularly, to a lubricating device for linear transmission mechanism.

2. Description of the Related Art

A regular liner transmission device, for example, linear guideway, generally comprises a guide member and a movable member, for example, a rail and a sliding block. The guide member is magnetically conductive, comprising at least one mounting hole for mounting at a support. The movable member is movable along the guide. The guide member and the movable member may wear quickly after a long use.

To solve the aforesaid wearing problem, two measures may be adopted. One measure is to coat the guide member with a layer of oil-containing material. The other measure is to install a lubricating device in the movable member to continuously dispense a storage lubricating oil. The aforesaid two measures can achieve a lubricating effect. Taiwan Patent Publication Number 1260374 discloses a lubricating device for this purpose. This design comprises a lubricant dispenser detachably mounted on the linear guideway for lubricating the linear guideway. By means of connecting a male connector and a female connector together, an oil passage defined in the male and female connectors is kept in communication between a nozzle hole of an end cap and an oil outlet of the lubricant dispenser for guiding the storage lubricating oil out of the lubricant dispenser into the nozzle hole of the end cap for lubricating the linear guideway. This design has the advantages of simple structure and ease of use. However, this design can simply dispense a lubricating oil of high flowability. It is not suitable for use in a place where a high level of environmental cleanliness should be maintained, such as clean room. For use in a clean room, a viscous lubricating grease should be used instead of a high volatility of lubricating oil. Thus, this design cannot satisfy the demands.

Further, Taiwan Patent Publication Number 1263744 discloses a lubricant dispenser, comprising an oil tank, a connector and a lubricant applicator. The oil tank comprises an oil transferring device. The connector has an oil absorbing substance mounted therein and kept in contact with the oil transferring device and the lubricant applicator for allowing the storage lubricating oil to be transferred from the oil tank to the grooved surface of the rail of the linear guideway. Further, the connector has two connecting portions respectively disposed at two distal ends thereof. One connecting portion is inserted through the lubricant applicator and coupled to the sliding block of the linear guideway. The other connecting portion is connected to the oil tank by a joint. This design is convenient for application. However, this design still cannot satisfy the demand because it is simply suitable for dispensing a lubricating oil of high flowability.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a lubricating device for linear transmission mechanism, which uses a lubricating grease to lubricate a linear transmission mechanism, eliminating the disadvantage of high volatility of a lubricating oil and allowing the linear transmission mechanism to be used in any place where a high level of environmental cleanliness should be maintained.

To achieve this and other objects of the present invention, a lubricating device is mounted on a linear transmission mechanism consisting of a guide member and a movable member. The guide member is magnetically conductive, comprising at least one mounting hole for mounting. The movable member is movable along the guide member. The lubricating device comprises a housing, a screw rod, a pressure member, a screw nut, a transmission member and a driving device. The housing is connected to movable member of the linear transmission mechanism and movable with the movable member and defining an axial direction and a radial direction. Further, the housing comprises an accommodation chamber and an opening extending along the axial direction and respectively formed on the inside and periphery thereof in equal cross section, and a lubricant dispensing hole disposed in communication with the accommodation chamber. The screw rod is mounted in the accommodation chamber along the axial direction, comprising a first end piece located on one end thereof and pivotally coupled to the housing, a second end piece located on an opposite end thereof, and a first transmission portion formed of a part of the periphery of the second end piece. The pressure member fits the opening in shape and is mounted in the accommodation chamber and movable along the axial direction, comprising a through hole for the passing of the second end piece of the screw rod. The pressure member defines with the housing a lubricant storage chamber in the accommodation chamber in communication with the lubricant dispensing hole. The volume of the lubricant storage chamber is relatively changed subject to movement of the pressure member in the accommodation chamber. The screw nut is threaded onto the screw rod, and driven by the screw rod to stop against the pressure member outside the lubricant storage chamber. The transmission member is located in the accommodation chamber outside the lubricant storage chamber and movable back and forth along the radial direction, comprising a transmission slot, a second transmission portion disposed in the transmission slot at one lateral side and a third transmission portion disposed in the transmission slot at the opposite lateral side. The second transmission portion and the third transmission portion are respectively disposed at two opposing sides relative to the first transmission portion of the screw rod and alternatively driven to rotate the first transmission portion in forcing the screw nut against the pressure member. The driving device is connected to the transmission member, and adapted for reciprocating the transmission member.

By means of the lubricating device provided by the present invention, the user can store a lubricating grease in the lubricant storage chamber and drive the driving device to reciprocate the transmission member. Thus, the second transmission portion and the third transmission portion can alternatively rotate the first transmission portion to move the screw nut against the pressure member, causing the pressure member to squeeze the storage lubricating grease out of the lubricant dispensing hole for lubricating the linear transmission mechanism.

DETAILED DESCRIPTION OF THE INVENTION

The advantages and features of the present invention will be fully understood by reference to the following examples in conjunction with the accompanying drawings.

Referring toFIGS. 1-5, a lubricating device10is shown mounted on a linear transmission mechanism80. The linear transmission mechanism80comprises a guide member81, and a movable member82. The guide member81is magnetic conductive, having at least one mounting hole811for mounting. The movable member82is movable along the guide member81. The lubricating device10comprises a housing11, a screw rod12, a pressure member13, a screw nut14, a transmission member15and a driving device16.

The housing11is connected to the movable member82of the linear transmission mechanism80and movable with the movable member82, defining an axial direction111and a radial direction112. The housing11comprises an accommodation chamber113and an opening114extending along the axial direction111and respectively formed on the inside and periphery thereof in equal cross section, and a lubricant dispensing hole115disposed in communication with the accommodation chamber113.

The screw rod12is mounted in the accommodation chamber113along the axial direction, comprising a first end piece121located on one end thereof and pivotally coupled to the housing11, a second end piece122located on an opposite end thereof, and a first transmission portion123formed of a part of the periphery of the second end piece122.

The pressure member13fits the opening114in shape. Further, the pressure member13is mounted in the accommodation chamber113and movable along the axial direction111, comprising a through hole131for the passing of the second end piece122of the screw rod12. The pressure member13defines with the housing11a lubricant storage chamber132in the accommodation chamber113. The lubricant storage chamber132is kept in communication with the lubricant dispensing hole115. Further, subject to movement of the pressure member13in the accommodation chamber113, the volume of the lubricant storage chamber132is relatively changed.

The screw nut14is threaded onto the screw rod12, and driven by the screw rod12to stop against the pressure member13outside the lubricant storage chamber132.

The transmission member15is located in the accommodation chamber113outside the lubricant storage chamber132, and movable back and forth along the radial direction112. The transmission member15comprises a transmission slot151, a second transmission portion152disposed in the transmission slot151at one lateral side, and a third transmission portion153disposed in the transmission slot151at the opposite lateral side. When moving the transmission member15to drive the screw rod12, the second transmission portion152and the third transmission portion153are respectively disposed at two opposing sides of the first transmission portion123of the screw rod12and alternatively driven to rotate the first transmission portion123, keeping the screw nut14to stop against the pressure member13.

The driving device16is connected to the transmission member15, and adapted for reciprocating the transmission member15.

During application, the user fills a lubricating grease into the lubricant storage chamber132. Thereafter, the driving device16drives the transmission member15to move back and forth along the axial direction111. During the reciprocating motion of the transmission member15, the second transmission portion152and the third transmission portion153alternatively rotate the first transmission portion123, causing the screw nut14to be moved against the pressure member13, and therefore the pressure member13is forced to squeeze the storage lubricating grease out of the lubricant dispensing hole115. It is to be noted that, the screw nut14is stopped at the pressure member13, and the friction resistance produced between the screw nut14and the pressure member13prohibits the screw nut14from rotation with the screw rod12, and therefore the screw nut14can force the pressure member13toward the inside of the housing11to squeeze the storage lubricating grease out of the lubricant dispensing hole115during rotation of the screw rod12. If the storage lubricating grease in the lubricant storage chamber132hinders the movement of the pressure member13, the screw nut14will be unstable to move the pressure member13, i.e., the pressure of the storage lubricating grease overcomes the friction resistance between the screw nut14and the pressure member13, causing the screw nut14to be rotated with the screw rod12.

By means of the lubricating device provided by the present invention, the user can store a lubricating grease in the lubricant storage chamber132and drive the driving device16to reciprocate the transmission member15. Thus, the second transmission portion152and the third transmission portion153can alternatively rotate the first transmission portion123to move the screw nut14against the pressure member13, causing the pressure member13to squeeze the storage lubricating grease out of the lubricant dispensing hole115for lubricating the linear transmission mechanism.

Referring toFIG. 5, in this embodiment, the transmission slot151forms a slot mouth154in the transmission member15; the first transmission portion123, the second transmission portion152and the third transmission portion153are tooth racks; the second transmission portion152is meshed with the first transmission portion123, and driven to rotate the first transmission portion123; the third transmission portion153is meshed with the first transmission portion123, and driven to rotate the first transmission portion123; the second transmission portion152and the third transmission portion153have the same length but are kept away from the slot mouth154at different distances.

As stated above, the first transmission portion123, the second transmission portion152and the third transmission portion153in this embodiment are tooth racks. Alternatively, the first transmission portion123, the second transmission portion152and the third transmission portion153can be a respective coarse surface. In this case, the second transmission portion152can rub against the first transmission portion123, thereby rotating the first transmission portion123; the third transmission portion153can rub against the first transmission portion123, thereby rotating the first transmission portion123. Similarly, the coarse surface design of the second transmission portion152and the coarse surface design of the third transmission portion153have the same length, however, they are kept away from the slot mouth154at different distances.

Referring toFIG. 6throughFIG. 13, an application example of the present invention, in which the first transmission portion123, the second transmission portion152and the third transmission portion153are respectively formed of a tooth rack, is shown. When the transmission slot151of the transmission member15is being moved toward the first transmission portion123of the screw rod12, the second transmission portion152and the third transmission portion153are alternatively forced to rotate the first transmission portion123. The second transmission portion152and the third transmission portion153can alternatively rotate the first transmission portion123only under the condition that the second transmission portion152and the third transmission portion153have the same length but are kept away from the slot mouth154at different distances.

Referring toFIGS. 14 and 15andFIGS. 3 and 6again, the driving device16comprises an elastic member161and a first magnetic member162. The elastic member161, for example, compression spring, is set between the housing11and the transmission member15, and stopped against the transmission member15and the housing11inside the accommodation chamber113. The first magnetic member162is connected to the transmission member15, and adapted for moving the transmission member15to overcome the spring force of the elastic member161and to move toward the guide member81. Thus, the lubricating device10that is mounted on the movable member82can be moved with the movable member82along the guide member81over the mounting hole811. As the guide member81is magnetically conductive, the first magnetic member162of the driving device16can carry the transmission member15to overcome the spring force of the elastic member161and to move toward the guide member81when the lubricating device10is moved with the movable member82along the guide member81. When the lubricating device10is moved over the mounting hole811, the magnetic attractive force that attracts the first magnetic member162toward the guide member81is relatively decreased, causing the spring force of the elastic member161to push the transmission member15away from the guide member81. Subject to the aforesaid mechanism, moving the movable member82along the guide member81causes the transmission member15to move along the radial direction112, driving the screw rod12to move the screw nut14against the pressure member13.

Referring toFIG. 16, an alternate form of the lubricating device in accordance with the present invention is shown. This alternate form is substantially similar to the embodiment shown inFIGS. 1-15with the exception that a second magnetic member163is connected to the pressure member13for attracting the screw nut14to adjust the friction force between the screw nut14and the pressure member13. Because the pressure imparted by the pressure member13is determined subject to the friction force between the pressure member13and the screw nut14, enhancing the friction force between the pressure member13and the screw nut14avoids rotation of the screw nut14with the screw rod12and increases the pressure of the screw nut14against the pressure member13. On the contrary, the screw nut14will be rotated with the screw rod12to reduce the pressure of the screw nut14against the pressure member13if the friction force between the pressure member13and the screw nut14is excessively low. By means of using the second magnetic member163to attract the screw nut14and adjusting the attractive force between the second magnetic member163and the screw nut14, the friction force between the screw nut14and the pressure member13is relatively adjusted.