Two-stage worm and gear planetary reducer

Abstract

According to the two-stage worm gear and worm planetary reducer, an input end worm and four sets of worm gears are matched in a planetary structure to conduct dispersed transmission, then transmission is conducted to coplanar gears through the four sets of two-stage worm gear and worm structures, the four sets of coplanar gears are consistent in speed and direction, then transmission is conducted to an output shaft through a center gear, and in this way, large-reduction-ratio transmission is provided; according to the robot speed reducer, large torque can be transmitted, reverse self-locking of motor transmission can be achieved, four sets of worm wheels and worms are adopted for transmission through a planetary structure, stress of a single set of worm wheels and worms can be shared, gear abrasion is reduced, meanwhile, axial stress of an input shaft is balanced, the reduction ratio of an existing robot speed reducer is smaller than 200, a band-type brake needs to be added to achieve power-off self-locking, and cost is high. The speed reducer provided by the invention is higher in reduction ratio and lower in cost.

Description

Technical Field

[0001] The present invention relates to an application of a two-stage worm gear planetary reducer, in particular to a usage scenario requiring reverse self-locking in an extremely large reduction ratio that cannot be provided by other reducers. Background Art

[0002] In the industrial robot industry, RV reducers, harmonic reducers, cycloid reducers, and planetary reducers are used.

[0003] The defects of the RV reducer principle structure: 1. Cycloid modification; 2. Large backlash; 3. The first stage reduction ratio is too small, and the second stage reduction ratio is too large; 4. Sliding friction; 5. The crankshaft speed is high and the output speed is low. Compared with the robot reducer with better performance, the RV reducer has a gap in transmission accuracy, return accuracy, accuracy retention, transmission efficiency and other performance.

[0004] The cycloid shaping has too high requirements on curve design, curve processing accuracy, processing accuracy of other parts, and bearing accuracy. The shaping affects the transmission accuracy of the reducer.

[0005] The movement of the needle roller is shaftless sliding, which requires clearance, otherwise it is easy to get stuck. In addition, the front-stage reduction of the reducer uses traditional gear transmission and also has backlash. Therefore, the backlash of the RV reducer is relatively large, and the backlash has a great influence on the return accuracy of the reducer.

[0006] The reasons why the reduction ratio of the final stage of the RV reducer is very large are: 1. The previous stage of reduction uses traditional gear reduction. Due to space limitations, the reduction ratio of traditional gear reduction is small, so the reduction ratio of the final stage transmission must be large; 2. The cycloid modification affects the transmission accuracy, and a large reduction ratio is conducive to obtaining high transmission accuracy; 3. The robot reducer requires a large load, and the cycloid pinwheel structure with a small tooth difference cannot arrange more crankshafts to share the load, so the bearing is subjected to great force and the bearing wears quickly. A large reduction ratio is conducive to reducing the force on the bearing, but the large reduction ratio means the crankshaft speed is high, and the bearing wears just as quickly. Therefore, the efficiency of the RV reducer is not very high, the accuracy retention is not very good, the service life is not very high, and the output speed is also low.

[0007] The needle roller motion of the cycloid pinwheel transmission with small tooth difference is shaftless sliding, mainly sliding friction, which has a larger friction coefficient than rolling friction, generates more frictional heat, and causes rapid wear of transmission components, which has a great impact on transmission accuracy, transmission efficiency and accuracy retention.

[0008] The use of a transmission mechanism with no curve modification, zero backlash, rolling friction, large reduction ratio, large load, high transmission accuracy, and high transmission efficiency can make the reducer achieve better performance. The planetary reducer has a small reduction ratio and no self-locking. Summary of the invention

[0009] The present invention includes a primary worm 1, a primary turbine 2, a bearing seat 3, a secondary worm 4, a secondary turbine 5, a first shell 6, a shaft 7, a bearing 8, a gear 9, a central gear 10, a bearing 11, an output shaft 12, a second shell 13, an output structure 14, and a shell 16.

[0010] The present invention transmits motion synchronously through multiple groups of worm gears, and finally moves synchronously to the output shaft. The present invention eliminates the stress wear and axial eccentric stress during the movement of a single group of worm gears, and retains the advantages of a large reduction ratio and self-locking of the worm gear structure. The transmission efficiency and gear wear conditions of this method need to be experimentally measured before a conclusion can be drawn. The present invention aims to protect this structural design method.

[0011] The present invention adopts multiple sets of two-stage worm gear transmission, adopts 0.5 module 20 teeth worm gear transmission, and the two-stage worm gear reduction ratio is 400.

[0012] The present invention not only includes a single-pole four-group worm gear planetary transmission, but also includes a single-pole three-group worm gear planetary transmission, which can reduce the size of the reducer structure, adapt to small motors, and reduce the reduction ratio. At present, the reducer outer diameter of 85, two-stage four-group worm gear reduction, and reduction ratio of 400 have been tested. And the outer diameter of 600, two-stage three-group worm gear reduction, and reduction ratio of 300.

[0013] The present invention applies for protection of a single-pole one-worm-gear multi-group worm gear planetary distributed transmission method, including a one-worm-gear with three groups and multiple groups of worm gear planetary distributed transmission methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural plan view of one layer of the present invention.

[0015] Figure 2 It is a three-dimensional diagram of the structure of one layer of the present invention.

[0016] Figure 3 It is a plan view of the two-story structure of the present invention.

[0017] Figure 4 It is a three-dimensional diagram of the two-layer structure of the present invention.

[0018] Figure 5 It is a three-dimensional diagram of the overall transmission of the two-layer and three-layer structure of the present invention.

[0019] Figure 6 It is the overall layout diagram of the appearance of the present invention.

[0020] Figure 7 It is a transmission structure diagram of a smaller-sized reducer of the present invention.

[0021] In the figure, a first-stage worm 1, a first-stage turbine 2, a bearing seat 3, a second-stage worm 4, a second-stage turbine 5, a first-layer casing 6, a shaft 7, a bearing 8, a gear 9, a central gear 10, a bearing 11, an output shaft 12, a second-layer casing 13, an output structure 14, and a casing 16 are provided. DETAILED DESCRIPTION

[0022] like Figure 1 , Figure 2 As shown, the input end is driven by the primary worm 1 in cooperation with the motor output end, and then transmitted to the coaxial secondary worm 4 through the planetary distribution with 4 sets of primary worm wheels 2, and then transmitted to the secondary worm wheel 5 through the secondary worm 4.

[0023] like Figure 3 , Figure 4 , Figure 5 As shown, a layer of two-stage worm gear 5 is transmitted to gear 9 through shaft 7, and shaft 7 is limited by bearing 8, and bearing 8 is installed on housing 13; four groups of gears 9 are in the same plane and have the same speed direction, and transmit the motion to the center gear 10, and then the center gear 10 outputs the motion through shaft 12, and shaft 12 is limited by two bearings 11.

[0024] like Figure 6 As shown, the output structure 14 is connected to the output shaft 12, and the output structure 14 is connected to the external structure through screw holes to output motion. The first shell 6, the second shell 13, and the third shell 16 are connected and assembled with the screw holes of the first shell 6 through the through holes 17.

[0025] like Figure 7 As shown, one layer of input shaft is transmitted to three sets of worm gears through the worm gear at the same time.

Claims

1. The present invention comprises a primary worm 1, a primary turbine 2, a bearing seat 3, a secondary worm 4, a secondary turbine 5, a first shell 6, a shaft 7, a bearing 8, a gear 9, a central gear 10, a bearing 11, an output shaft 12, a second shell 13, an output structure 14, and a shell 16.

2. The present invention transmits motion synchronously through multiple groups of worm gears, and finally moves synchronously to the output shaft. The present invention eliminates the stress wear and axial eccentric stress during the movement of a single group of worm gears, and retains the advantages of a large reduction ratio and self-locking of the worm gear structure. The transmission efficiency and gear wear of this method require experimental measurement to draw conclusions, and the present invention aims to protect this structural design method.

3. The present invention adopts multiple sets of two-stage worm gear transmission, adopts 0.5 module 20 teeth worm gear transmission, and the two-stage worm gear reduction ratio is 400.

4. The present invention not only includes a single-pole four-group worm gear planetary transmission, but also includes a single-pole three-group worm gear planetary transmission, which can reduce the size of the reducer structure, adapt to small motors, and the reduction ratio can also be reduced according to the number of worm gear teeth. At present, the reducer outer diameter of 85, two-stage four-group worm gear reduction, and the reduction ratio of 400 have been tested. And the outer diameter of 640, two-stage three-group worm gear reduction, and the reduction ratio of 400.

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