Patent Application
20130047769
1. Technical Field
The present disclosure generally relates to robot technologies, and particularly to an industrial robot with a gear transmission mechanism.
2. Description of the Related Art
Referring to
Generally, the robot 100 is provided with an electric motor and a speed reducer (not shown) to drive the upper arm 15. The speed reducer may be a rotary vector (RV) speed reducer or a harmonic drive (HD) speed reducer. However, both the RV speed reducer and the HD speed reducer are expensive. In addition, cables connected to the RV speed reducer or the HD speed reducer for supplying power or control signal directions have to be received inside the upper arm 15, and as a result the cables are vulnerable to damage by abrasion or by being twisted.
Therefore, there is room for improvement within the art.
The components in the drawings are not necessarily drawn to scale, the emphasis instead placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
Referring to
Referring to
The gear box 31 comprises a main body 311, a first cover 313, and a second cover 315. The main body 311 comprises a first box 3111 and a second box 3113 connected to the first box 3111. The first cover 313 is fixed to the first box 3111, and together with the first box 3111 forms a first receiving groove 3115 for receiving the first transmission mechanism 36. The second cover 315 is fixed to the second box 3113, and, with the second box 3113, forms a second receiving groove 3116 for receiving the second transmission mechanism 37. In an illustrated embodiment, the second box 3113 is substantially perpendicularly connected to the first box 3111.
The first driving member 33 is fixed to a top wall of the first box 3111, and the second driving member 35 is fixed to the second cover 315. The first driving member 33 comprises a first driving shaft 331 extending through the top wall of the first box 3111, and the second driving member 35 comprises a second driving shaft 351 extending through the second cover 315. In the illustrated embodiment, the first driving member 33 and the second driving member 35 are servo motors.
The first transmission mechanism 36 comprises a gap adjusting assembly 360, a first gear 361, a second gear 362, a third gear 363, a fourth gear 364, a fixed shaft 365, a first bearing 366, a second bearing 367, a third bearing 368, and a fourth bearing 369. The first gear 361 meshes with the second gear 362. The second gear 362 is fixed to the third gear 363. The third gear 363 meshes with the fourth gear 364. The fourth gear 364 is rotatably sleeved on the fixed shaft 365. The gap adjusting assembly 360 adjusts a gap between the third gear 363 and the fourth gear 364. In the illustrated embodiment, the third gear 363 and the fourth gear 364 are bevel gears.
The first bearing 366 and the third bearing 368 are fixed to the first box 3111. The second bearing 367 and the fourth bearing 369 are fixed to the first cover 313. The first bearing 366 is aligned with the second bearing 367, and the third bearing 368 is aligned with the fourth bearing 369.
The first gear 361 is fixed to the first driving shaft 331. The third gear 363 comprises a gear shaft (not labeled), and the first bearing 366 and the third bearing 368 are positioned on opposite ends of the gear shaft of the third gear 363. The second gear 362 fixedly sleeves on the gear shaft of the third gear 363. The fourth gear 364 is fixed to a bottom wall of the gear box 31. The fixed shaft 365 extends through the third bearing 368 and the fourth bearing 369, and is fixed to the base 20.
The third gear 363 defines a positioning hole 3631 in an end adjacent to the first bearing 366. The gap adjusting assembly 360 comprises an elastic member 3601, a fastener 3603, and a resisting member 3605. The resisting member 3605 and the elastic member 3601 are received in the positioning hole 3631 in that order. The fastener 3603 is fixed on the first box 3111, and abuts against the elastic member 3601. In the illustrated embodiment, the resisting member 3605 is a steel ball, the elastic member 3601 is a compression spring, and the fastener 3603 is a screw. The fastener 3603 can be moved towards the third gear 363 by a screwdriver (not shown), and then the third gear 363 is driven to move by the resisting member 3605, such that the gap between the third gear 363 and the fourth gear 364 decreases, because the third gear 363 and the fourth gear 364 are bevel gears. That is, the third gear 363 can be driven to move to mesh with the fourth gear 364 more tightly by adjusting the fastener 3603.
When the first driving member 33 is working, the first driving shaft 331 drives the first gear 361 to rotate, and then the first gear 361 drives the second gear 362 to rotate. The second gear 362 drives the third gear 363 to rotate on the first bearing 366 and the second bearing 367. The third gear 363 drives the fourth gear 364 to rotate. The gear box 31 rotates about the fixed shaft 365 together with the fourth gear 364 because the fourth gear 364 is fixed to the gear box 31.
In the illustrated embodiment, the first gear 361, the second gear 362, the third gear 363, and the fourth gear 364 are spur involute gears. A rotating axis of the first driving shaft 331, a rotating axis of the second gear 362, and a rotating axis of the fourth gear 364 are substantially parallel to each other. The manufacturing costs of the first gear 361, the second gear 362, the third gear 363, and the fourth gear 364 are relatively low, comparing with the related art speed reducer. Therefore, the industrial robot 200 has a low manufacturing cost. A total reduction ratio of the first transmission mechanism 36 can be adjusted by changing a number of teeth of the first gear 361, the second gear 362, the third gear 363, and the fourth gear 364. For example, a reduction ratio between the first gear 361 and the second gear 362 may be 11, and a reduction ratio between the third gear 363 and the fourth gear 364 may be 5, thus the total reduction ratio of the first transmission mechanism 36 is 55.
In an alternative embodiment, the first transmission mechanism 36 may only comprise the first gear 361 and the fourth gear 364 directly meshing with the first gear 361.
The second transmission mechanism 37 has a similar structure to the first transmission mechanism 36. The second transmission mechanism 37 comprises a gap adjusting assembly 370, a fifth gear 371, a sixth gear 372, a seventh gear 373, an eighth gear 374, an output shaft 375, a fifth bearing 376, a sixth bearing 377, a seventh bearing 378, and an eighth bearing 379. The fifth gear 371 meshes with the sixth gear 372. The sixth gear 372 is fixed to the seventh bearing 378. The seventh bearing 378 meshes with the eighth gear 374, and the eighth gear 374 is fixedly sleeved on the output shaft 375. The gap adjusting assembly 370 of the second transmission mechanism 37 has the same structure as the gap adjusting assembly 360 of the first transmission mechanism 36. The gap adjusting assembly 370 adjusts a gap between the seventh gear 373 and the eighth gear 374.
The fifth bearing 376 and the seventh bearing 378 are fixed to the second box 3113. The sixth bearing 377 and the eighth bearing 379 are fixed to the second cover 315. The fifth bearing 376 aligns with the sixth bearing 377, and the seventh bearing 378 aligns with the eighth bearing 379.
When the second driving member 35 is working, the second driving shaft 351 rotates the fifth gear 371, and the fifth gear 371 rotates the sixth gear 372. The sixth gear 372 rotates the seventh gear 373 on the fifth bearing 376 and the sixth bearing 377. The seventh gear 373 rotates the eighth gear 374. The output shaft 375 rotates on the seventh bearing 378 and the eighth bearing 379 together with the fourth gear 364 because the eighth gear 374 is fixed to the output shaft 375.
In the illustrated embodiment, the fifth gear 371, the sixth gear 372, the seventh gear 373, and the eighth gear 374 are spur involute gears. A rotating axis of the second driving shaft 351, a rotating axis of the sixth gear 372, a rotating axis of the eighth gear 374, and a rotating axis of the output shaft 375 are substantially parallel to each other. The manufacturing costs of the fifth gear 371, the sixth gear 372, the seventh gear 373, and the eighth gear 374 are low, compared with the related art speed reducer. Therefore, the manufacturing cost of the industrial robot 200 is further reduced. A total reduction ratio of the second transmission mechanism 37 can be adjusted by changing a number of teeth of the fifth gear 371, the sixth gear 372, the seventh gear 373, and the eighth gear 374. For example, a reduction ratio between the fifth gear 371 and the sixth gear 372 may be 11, and a reduction ratio between the seventh gear 373 and the eighth gear 374 may be 5, thus the total reduction ratio of the second transmission mechanism 37 is 55.
In an alternative embodiment, the first transmission mechanism 36 may only comprise the fifth gear 371 directly meshed with the eighth gear 374.
While the present disclosure has been described with reference to particular embodiments, the description is illustrative of the disclosure and is not to be construed as limiting the disclosure. Therefore, various modifications can be made to the embodiments by those of ordinary skill in the art without departing from the true spirit and scope of the disclosure, as defined by the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201110255040.7 | Aug 2011 | CN | national |
