JPH0596599U - Linear actuator - Google Patents

Abstract

(57) [Abstract] [Purpose] A constant amount of lubricating oil is constantly supplied to the linear shaft and bearings to prevent rust on the rotating contact surface and ensure smooth linear movement to improve position control accuracy. To do. [Structure] A plurality of bearings 5 obliquely abutting on the outer peripheral surface 2a of the linear shaft 2 are attached to the moving block 1 and supported by the linear shaft 2, and the linear shaft 2 is rotated to move the moving block 1 along the linear shaft 2. In a linear actuator that linearly moves in a linear manner, an oil storage chamber 6 that stores lubricating oil 7 is formed inside the moving block 1, and an oil transmission ring 8 is fitted into a linear shaft 2 that is inserted through the oil storage chamber 6 and The lower portion of the oil transmission ring 8 is dipped in the lubricating oil 7 in the oil storage chamber 6, and when the linear shaft 2 rotates, the oil transmission ring 8 in the oil storage chamber 6 is also rotated, and the oil transmission ring 8 causes the oil to move. Lubricating oil 7 in the storage chamber 6
Can be supplied to the linear shaft 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a linear actuator that linearly moves a moving block by sandwiching the smooth surface of the linear shaft diagonally with the bearings of the moving block and rotating the linear shaft.In particular, a constant amount of lubricating oil is always supplied to the rotating contact surface. Regarding linear actuators made possible.

[0002]

[Prior Art]

 A linear driving device used for driving a linear table or the like includes a cylindrical linear shaft that serves as a rotating shaft, a moving block that is inserted into the linear shaft and supported to move in the shaft direction, and a shaft of the moving block. A linear actuator is known which is composed of bearings mounted on both side surfaces in the direction and sandwiching a smooth outer peripheral surface of the shaft at an angle. In this linear actuator, for example, three bearings that are obliquely abutted against the outer peripheral surface of the shaft are attached to both side surfaces of the moving block. It can be moved linearly before and after the direction. Therefore, for example, in a linear table used for a work table or the like, if the table body serving as a moving body is supported by a moving block of a linear actuator, the table body can be linearly moved. In such a linear actuator, generally, the rotating contact surfaces of the linear shaft and the bearing are driven without lubrication, and the lubricating oil is not supplied to the linear shaft and the bearing portion.

[0003]

[Problems to be solved by the device]

 As mentioned above, the linear actuator can perform smooth linear motion without lubrication, but rust may occur on the contact surface of the linear shaft or bearing depending on the operating environment, which hinders the smooth motion of the moving shaft. Will be a factor. Therefore, it is conceivable to directly lubricate the linear shaft and bearings directly from the outside, but this type of lubricating oil supply method is complicated, and a large amount of lubricating oil is applied to the rotating contact surface. Dust adheres to the surface of the actuator and adversely affects the smooth driving of the actuator, resulting in a decrease in position control accuracy.

The present invention has been proposed in order to solve the problems of the conventional techniques described above, and it is possible to always supply a constant amount of lubricating oil to the linear shaft and the bearing portion, thereby enabling rotation. It is an object of the present invention to provide a linear actuator that can prevent rust and dust from adhering to the contact surface, ensure smooth linear motion, and improve the accuracy of position control.

[0005]

[Means for Solving the Problems]

 In order to achieve this object, in the present invention, a plurality of bearings that obliquely abut the outer peripheral surface of a cylindrical linear shaft are attached to a moving block, and these moving blocks are supported on the linear shaft by these bearings. In a linear actuator that linearly moves the moving block along the linear shaft by rotating the shaft, an oil storage chamber for storing lubricating oil is formed inside the moving block, and the oil storage chamber is inserted through the oil storage chamber. Insert the oil transmission ring into the linear shaft, immerse the lower part of the oil transmission ring in the lubricating oil in the oil storage chamber, and rotate the oil transmission ring in the oil storage chamber together when the linear shaft rotates. With this oil transmission ring, the lubricating oil in the oil storage chamber is supplied to the linear shaft.

[0006]

[Action]

 According to the above configuration, when the linear shaft rotates and the moving block moves along the shaft, the oil transmission ring inserted in the shaft rotates in the oil storage chamber to remove the lubricating oil in the storage chamber. Since it is sent to the shaft side, a fixed amount of lubricating oil can always be applied uniformly to the outer peripheral surface of the linear shaft. Further, since the bearing rotates while contacting the outer peripheral surface of the linear shaft coated with the lubricating oil, the lubricating oil is evenly coated on the outer peripheral surface of the bearing.

[0007]

【Example】

 Hereinafter, a specific embodiment of the linear actuator according to the present invention will be described in detail with reference to the drawings. FIG. 1 shows an external view of this linear actuator, FIG. 2 shows its side view, and FIG. 3 shows its front view. First, the basic configuration of the linear actuator will be described. The moving block 1 is composed of upper and lower block halves (half bodies) 1A and 1B, and the linear shaft 2 of a round bar is sandwiched between these block halves 1A and 1B and is tightened by two tightening bolts 3 and 3 to move. The block 1 is attached to the outer peripheral portion of the linear shaft 2. Bearings 5 and 5 are attached to the block half 1A on the upper side in the drawing, and bearings 5 are attached to the block half 1B on the lower side in a diagonal manner with respect to the shaft 2, respectively, on both sides of the moving block 1 in the movement direction. The outer rings 5a of the bearing 5, which are provided in six pieces on both sides, are in contact with the outer peripheral surface 2a of the smooth shaft 2 at an angle. As a result, when the linear shaft 2 is rotationally driven, the moving block 1 moves linearly along the shaft 2 and a moving body such as a table (not shown) fixed to the moving block 1 can be linearly driven in the shaft direction. it can.

Next, a lubricating oil supply mechanism provided in this linear actuator will be described with reference to FIGS. 4 to 6. An oil storage chamber 6 with an upper opening is formed by hollowing out the inside of the block half 1B on the lower side, and a lubricating oil 7 is stored at the bottom of the storage chamber 6. The lubricating oil 7 having a high traction coefficient is used. An oil transmission ring 8 is fitted to the linear shaft 2 so as to be located in the oil storage chamber 6, and the lower side of the ring 8 hanging downward is dipped in the lubricating oil 7 in the storage chamber 6. There is. As the oil transmission ring 8, for example, a felt ring, a silicon rubber ring, a metal ring or the like, which is easily impregnated with oil, can be used. Further, a recess 9 is cut out in the lower surface of the upper block half 1A, and a space is secured so that the oil transmission ring 8 fitted in the linear shaft 2 can freely move.

In the linear actuator configured as described above, when the linear shaft 2 rotates and the moving block 1 moves linearly, the oil transmission ring 8 immersed in the lubricating oil 7 rotates inside the oil storage chamber 6. . By the rotation of the ring 8, the lubricating oil 7 in the storage chamber 6 is always carried by the ring 8 to the shaft 2 side, so that an oil film is formed on the outer peripheral surface 2a of the shaft and abuts on the linear shaft 2. An oil film is also formed on the outer peripheral surface of the outer ring of the bearing 5 that rotates together. As a result, it is possible to prevent rust from occurring on the outer peripheral surface 2a of the shaft and the outer peripheral surface of the outer ring of the bearing 5. Further, the oil film formed on the rotary contact surface between the linear shaft 2 and the bearing 5 enables traction drive. In this traction drive, a resistance force is generated when the elastic fluid lubricating oil film (EHL oil film) formed on the rolling contact surface is sheared, and the frictional force between the linear shaft 2 and the bearing 5 can be increased.

[0010]

[Effect of the device]

 As described above, according to the present invention, since a constant amount of lubricating oil can be supplied between the linear shaft and the bearing, the generation of rust on the linear shaft and the bearing can be prevented regardless of the usage environment of the linear actuator. It is possible to ensure smooth linear drive of the actuator. Also, unlike lubricating oil directly to the linear shaft and bearings, the supply of lubricating oil can be maintained at an appropriate amount, so dust does not adhere to the rotating contact surface. Further, the EHL oil film formed on the rotating contact surfaces of the linear shaft and the bearing can perform traction drive, and the frictional force between the linear shaft and the bearing can be increased. As a result, there is no transmission loss of rotational force due to slippage on the rotary contact surface, and the accuracy of position control of linear motion can be improved.

[Brief description of drawings]

FIG. 1 is an external perspective view showing an embodiment of a linear actuator according to the present invention.

FIG. 2 is a side view of the linear actuator of FIG.

FIG. 3 is a front view of the linear actuator.

FIG. 4 is a plan view of the linear actuator.

5 is a cross-sectional view taken along the line AA of FIG.

6 is a sectional view taken along line BB of FIG.

[Explanation of symbols]

1 Moving Block 1A Upper Block Half 1B Lower Block Half 2 Linear Shaft 2a Outer Surface 3 Bolt 5 Bearing 5a Outer Ring 6 Oil Storage Chamber 7 Lubricating Oil 8 Oil Transmission Ring 9 Recess

Claims (1)

[Scope of utility model registration request] 1. A plurality of bearings obliquely abutting on the outer peripheral surface of a cylindrical linear shaft are attached to a moving block, the moving block is supported on the linear shaft by these bearings, and the linear shaft is rotated to thereby perform the above. In a linear actuator that linearly moves a moving block along the linear shaft, an oil storage chamber that stores lubricating oil is formed inside the moving block, and an oil transmission ring is provided on the linear shaft that is inserted through the oil storage chamber. At the same time as fitting, soak the lower part of the oil transmission ring in the lubricating oil in the oil storage chamber, and when the linear shaft rotates, rotate the oil transmission ring in the oil storage chamber together, and use this oil transmission ring to move the oil in the oil storage chamber. A linear actuator characterized by supplying lubricating oil to a linear shaft.