JP4936049B2 - Gear device and robot and robot system using the same - Google Patents

Description

    The present invention relates to a structure for removing and adjusting a backlash of a gear device.

Conventionally, there is a gear device equipped with a spring in order to remove and adjust the backlash of the gear (for example, Patent Document 1). Patent Document 1 discloses a configuration for removing tooth backlash caused by gear tooth wear when the gear is subjected to frequent forward rotation, reverse rotation operation, and instantaneous stop operation. In Patent Document 1, the shape of gears that mesh with each other is tapered, and one of the gears is urged in a direction in which the gears mesh with each other by a spring to remove backlash generated between the gears.
JP-A-5-39824

However, it goes without saying that when the spring force of the gear spring provided for removing the backlash decreases, the backlash occurs again. It has been found that this spring force is reduced due to wear in the axial direction of the spring.
The occurrence of this wear will be described with reference to FIG. FIG. 6 shows a configuration of a conventional gear similar to that of Patent Document 1. The first gear 1 meshes with the second gear 2 at a substantially right angle with a tapered tooth surface. The second gear 2 is connected to, for example, a rotating shaft of a motor and rotates to rotate the first gear 1. The first gear 1 is engaged with the rotary shaft 3 by an involute spline or a key. Therefore, the first gear 1 can move a little while sliding in the axial direction of the rotating shaft 3 (left-right direction in FIG. 6). A coil spring 5 is provided at the end of the first gear 1 on the side opposite to the tapered tooth surface. The coil spring 5 and the first gear 1 are held between the rotating shaft 3 and a part 6 of the rotating shaft. A part 6 of the rotating shaft is separable from the rotating shaft 3 and is fixed to the rotating shaft 3 with a screw or the like. Accordingly, the first gear 1 is urged to the right in FIG. 6 by the spring force of the coil spring 5, meshes with the second gear 2 so as to remove backlash, and rotates together with the rotating shaft 3.
However, in such a configuration, when the first and second gears operate at a high frequency, the tooth surface and the engaging portion of the involute spline or key are worn, and the rotation direction of the first gear 1 and the rotary shaft 3 is worn. Therefore, the coil spring 5 is worn away.
Therefore, in the gear device equipped with the conventional spring represented by Patent Document 1, the spring provided for removing the backlash is worn as described above and the spring force is reduced, so that the backlash can be removed appropriately. It has been lost, reducing the life and reliability of the gear unit.
In particular, industrial robots employ a large number of gear transmission structures to transmit the rotational force from the motor rotation shaft at each part of the arm that has limited space, but the robot performs precise work. As described above, a gear that generates backlash is very problematic.
Therefore, the present invention discloses a highly reliable gear device that can continuously remove backlash in order to solve the above-described problems.

In order to solve the above problems, the present invention is configured as follows.
According to the first aspect of the present invention, the first gear and the second gear meshing with each other by the tapered gear, the first gear is fitted to the periphery, and the first gear can be slid in the axial direction. A rotating shaft that rotates together with the first gear, and the second gear along the axial direction so as to remove backlash of the first and second gears. An urging means for urging the rotation shaft, wherein the gear device is, in order from one end of the rotation shaft, fixed to the rotation shaft at one end of the rotation shaft with a screw. When one end is constrained to a member for the engagement with respect to a rotational direction of the rotary shaft, a coil spring whose other end is constrained to the first gear with respect to the rotation direction before Symbol rotation axis, by the coil spring The first gear that is biased toward the second gear. And a gear apparatus characterized by.
According to a second aspect of the present invention, the restraining portion is a pin provided on a contact surface between the locking member and the coil spring and a contact surface between the coil spring and the first gear. A gear device according to claim 1 is provided.
According to a third aspect of the present invention, the restraining portion is configured such that both ends of the coil of the coil spring are latched by a recess provided in the locking member and a recess provided in the first gear. 2. The gear device according to claim 1, wherein the gear device is formed.
According to a fourth aspect of the present invention, a first gear and a second gear meshing with each other with a tapered gear, the first gear is fitted to the periphery, and the first gear can be slid in the axial direction. A rotating shaft that rotates together with the first gear, and the second gear along the axial direction so as to remove backlash of the first and second gears. An urging means for urging the rotation shaft, wherein the gear device is, in order from one end of the rotation shaft, fixed to the rotation shaft at one end of the rotation shaft with a screw. When one end is constrained to a member for the engagement with respect to a rotational direction of the rotary shaft, a disc spring other end of which is constrained to the first gear with respect to the rotation direction of the pre-Symbol rotation axis, said dish The first gear that is biased toward the second gear by a spring. And a gear device according to symptoms.
According to a fifth aspect of the present invention, the restraining portion includes a pin provided on a contact surface between the locking member and the disc spring and a contact surface between the disc spring and the first gear. The gear device according to claim 4, wherein
According to a sixth aspect of the present invention, in the restraining portion, the convex portion provided on the disc spring is latched with the concave portion provided on the locking member and the concave portion provided on the first gear. The gear device according to claim 4, wherein the gear device is formed as described above.
The invention described in claim 7 is a robot incorporating the gear device according to claim 1 or 4.
The invention described in claim 8 is a robot system including the robot described in claim 7 and a controller for controlling the robot.

  According to the present invention, since the coil spring and the disc spring are reliably rotated integrally with the first gear and the rotating shaft by the restraining portion, the friction with the first gear and the rotating shaft does not occur, and the spring force is not generated. It does not decline. Therefore, there is an effect that the backlash adjustment by the spring force of the coil spring or the disc spring is sustained and the gear device is highly reliable. Further, with a robot using this gear device, the trajectory accuracy of the robot is less likely to be out of order even if the total operating time is increased.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 5 shows a side view of an industrial robot using the gear device of the present invention. The industrial robot operates under the control of a controller (not shown), and is installed as a robot system together with this controller to perform a predetermined work. In the figure, 51 is a fixed base, 52 is a revolving barrel, 53 is a first arm, and is supported on the revolving barrel 52 so as to be freely rotatable. Reference numeral 54 denotes a second arm, and an end portion thereof is supported so as to be freely rotatable with respect to the first arm 53. Reference numeral 55 denotes a shaft that can freely rotate with respect to the second arm. A wrist portion 56 is rotatably supported at the other end portion of the second arm 54, and a portion 57 having a pivotable axis is provided at the lower portion of the wrist portion 56. In FIG. 5, a wrist 56 is a shaft driven by the gear of the present invention, and FIG.

  In FIG. 1, the same number is attached | subjected to the same location as FIG. 6 which shows a conventional structure. In FIG. 1, reference numeral 1 denotes a first gear having a tapered gear shape, and 2 denotes a second gear which meshes with the first gear 1 with a tapered tooth surface. Reference numeral 3 denotes a rotating shaft for transmitting the power of the first gear 1, and 4 denotes an involute spline or key provided on the rotating shaft 3. The first gear 1 can move a little in the axial direction of the rotary shaft 3 by the involute spline or key, and the first gear 1 rotates the rotary shaft 3. Reference numeral 5 denotes a coil spring for urging the first gear 1 in the axial direction (left-right direction in the figure) to remove backlash with the second gear 2. Reference numeral 6 denotes a part of the rotating shaft 3, which holds the coil spring 5 and the first gear 1 on the rotating shaft 3. A part 6 of the rotating shaft is fixed to the rotating shaft 3 with a screw or the like. Therefore, a part 6 of the rotating shaft rotates together with the rotating shaft 3 and the first gear 1. In the present invention, the pin 7 that completely restrains the coil spring 5 in the rotational direction with respect to the part 6 of the rotating shaft and the first gear 1 is provided. One of the pins 7 is inserted into a pin hole provided on the coil spring 5 side and the part 6 side of the rotating shaft of the contact surface 9 between the coil spring 5 and the part 6 of the rotating shaft. Further, the other pin is inserted into the contact surface 9 between the first gear 1 and the coil spring 5 by providing a similar pin hole and restricts the rotational direction of the coil spring 5.

  FIG. 2 shows a shape in which both ends 10 (ends of a spring wire) of the coil spring 5 can be directly hooked to the part 6 of the rotating shaft and the first gear 1 instead of the pin 7 in FIG. The Example at the time of using the coil spring 5 which was made is shown. In this case, since the part 6 of the rotary shaft and the first gear 1 are directly assembled to the coil spring 5, the ease of assembly and the simplification of the device can be obtained as compared with the first embodiment. .

  FIG. 3 shows an embodiment in which a disc spring 8 is used instead of the coil spring 5 in FIG. Then, the pin 7 is inserted into the contact surface between the disc spring 8 and the part 6 of the rotating shaft and the contact surface between the disc spring 8 and the first gear 1, thereby rotating the disc spring 8 in the rotational direction position. The backlash adjustment of the first and second gears can be reliably performed by the spring force of the disc spring 8 while preventing the deviation.

FIG. 4 shows an embodiment in which a convex portion 11 is provided on a disc spring 8 in place of the pin 7 in FIG. 3, and the portion 6 of the rotating shaft and the first gear 1 can be directly latched. Show. In this case, since the part 6 of the rotating shaft 6 and the first gear 1 are assembled directly to the disc spring 8, the ease of assembly and the simplification of the device are obtained as compared with the third embodiment. It is done.

Sectional drawing which shows 1st Example of the gear apparatus of this invention. Sectional drawing which shows 2nd Example of the gear apparatus of this invention. Sectional drawing which shows 3rd Example of the gear apparatus of this invention. Sectional drawing which shows 4th Example of the gear apparatus of this invention. The side view of the industrial robot which uses the gear apparatus of this invention. Sectional drawing which shows the conventional gear apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 1st gear 2 2nd gear 3 Rotating shaft 4 Involute spline or key 5 Coil spring 6 A part of rotating shaft 7 Pin 8 Disc spring 9 Contact surface 10 End of coil spring 11 Convex part

Claims (8)

The first gear and the second gear meshing with each other with a tapered gear, and the first gear are fitted around the first gear, and the first gear is supported so as to be slidable in the axial direction. A rotating shaft that rotates together with the first gear, and a bias that biases the first gear toward the second gear along the axial direction so as to eliminate backlash of the first and second gears. A gear device comprising:
The gear device, in order from one end of the rotating shaft,
A locking member fixed to the rotating shaft with a screw at one end of the rotating shaft;
And one end of which is constrained to a member for the engagement with respect to a rotational direction of the rotary shaft, the other end is constrained to the first gear with respect to the rotation direction before Symbol rotation axis coil spring,
The first gear biased toward the second gear by the coil spring;
A gear device comprising:   2. The restraint portion is a pin provided on a contact surface between the locking member and the coil spring and a contact surface between the coil spring and the first gear. The gear device described.   The said restraint part is formed so that both ends of the coil of the said coil spring may be latched in the recessed part provided in the said locking member, and the recessed part provided in said 1st gearwheel. The gear device according to claim 1. The first gear and the second gear meshing with each other with a tapered gear, and the first gear are fitted around the first gear, and the first gear is supported so as to be slidable in the axial direction. A rotating shaft that rotates together with the first gear, and a bias that biases the first gear toward the second gear along the axial direction so as to eliminate backlash of the first and second gears. A gear device comprising:
The gear device, in order from one end of the rotating shaft,
A locking member fixed to the rotating shaft with a screw at one end of the rotating shaft;
One end of which is constrained to a member for the engagement with respect to a rotational direction of the rotary shaft, a disc spring other end of which is constrained to the first gear with respect to the rotation direction of the pre-Symbol rotary shaft,
The first gear biased toward the second gear by the disc spring;
A gear device comprising:   The restraint portion is a pin provided on a contact surface between the locking member and the disc spring and a contact surface between the disc spring and the first gear. Item 5. The gear device according to Item 4.   The constraining portion is formed such that a convex portion provided on the disc spring is latched with a concave portion provided on the locking member and a concave portion provided on the first gear. The gear device according to claim 4, wherein the gear device is provided.   A robot comprising the gear device according to claim 1 or 4. A robot system comprising the robot according to claim 7 and a controller for controlling the robot.

Images