Continuously variable transmission with spiral reducing screw rod
By designing a variable diameter lead screw and transmission ring, the problems of wear and insufficient friction in continuously variable transmissions under high torque conditions are solved, achieving efficient, uniform, and high-efficiency transmission with stepless speed regulation.
Patent Information
- Application Number
- CN202511724303.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-23
- Publication Date
- 2026-01-20
AI Technical Summary
Existing continuously variable transmissions (CVTs) are prone to wear and breakage under high torque conditions, have high steel belt maintenance costs, and have small contact area and insufficient friction between the cone pulley and the chain belt, making it difficult to achieve efficient stepless speed regulation.
It adopts a screw-type variable diameter structure, which drives the right-hand and left-hand screws to slide axially through the input gear. Combined with the planar spiral groove of the variable diameter wheel, it drives the slider to slide along the guide wheel groove, realizing continuous change of transmission ratio. The transmission ring replaces the steel belt/chain, and the multiple sets of trapezoidal grooves of the slider replace the conical wheel to press and increase tension.
This achieves a comprehensive performance improvement in continuously variable transmissions (CVTs), resulting in a simpler structure, greater durability, smoother speed changes, higher efficiency, and greater torque.
Smart Images
Figure CN121363618A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application belongs to the technical field of transmission, and particularly relates to a screw rod screw variable-diameter continuously variable transmission. BACKGROUND
[0002] The continuously variable transmission is a type of transmission, which realizes continuously variable speed by continuously changing the transmission ratio through two groups of pulleys and steel transmission belts (or chains); the commonly used steel belt / steel chain transmission is difficult to withstand large torque, is not suitable for intense driving or large displacement vehicles, and the steel belt is easy to wear, break and maintain after long-term use; the contact area of the linkage of the variable speed mechanism cone and the chain belt is relatively small, and is constantly changing, which is quite different from rigid connection; although the tension can be increased and the friction force can be increased by tightening the cone, it still cannot fundamentally solve the problem; therefore, how to improve the comprehensive performance of the continuously variable transmission is a technical problem to be solved. SUMMARY TECHNICAL PROBLEM
[0003] In view of the deficiencies of the prior art, the present application provides a screw rod screw variable-diameter continuously variable transmission, the input gear (100) drives the input wheel (1) to rotate, the driving motor (6) synchronously drives the right-handed screw rod (7) and the left-handed screw rod (8) to axially slide through the linkage block (9), and the right-handed screw rod sleeve (103) and the left-handed screw rod sleeve (203) rotate in opposite directions in the radial direction; the input wheel (1) and the variable-diameter wheel in the output wheel (2) rotate in opposite directions in the radial direction, and the planar spiral groove of the variable-diameter wheel drives the sliding block to slide in the sliding groove of the guide wheel; the circular diameter of the sliding block group in the input wheel (1) expands, and the circular diameter of the sliding block group in the output wheel (2) shrinks; conversely, the input wheel shrinks, and the output wheel expands; the axial distance of the screw rod is controlled, the transmission ratio is continuously changed, and continuously variable speed is realized; the continuously variable transmission of the screw rod screw variable-diameter uses the transmission ring (3) to replace the traditional steel belt / steel chain transmission, and uses the sliding block group of the screw rod screw variable-diameter structure to replace the traditional cone tightening to increase the tension and change the speed, and the present application has the advantages of simple structure, durability, uniform speed change, high efficiency, large torque and high comprehensive performance. SOLUTION
[0004] To achieve the above purpose, the present application is implemented by the following technical scheme, a continuously variable transmission of a screw rod screw variable-diameter, characterized in that: the first guide wheel, the second guide wheel, the third guide wheel, the fourth guide wheel, the fifth guide wheel and the sixth guide wheel are fixed on the first fixed disc and the second fixed disc to form an input wheel; The right-handed screw rod is linked in the radial direction through the outer spline and the inner spline of the input wheel, and rotates synchronously, the right-handed screw rod drives the right-handed screw rod sleeve to rotate in the radial direction through the axial sliding of the screw rod to the outside, the right-handed screw rod sleeve is linked in the radial direction through the outer spline and the inner spline of the first variable-diameter wheel, the second variable-diameter wheel, the third variable-diameter wheel, the fourth variable-diameter wheel, the fifth variable-diameter wheel and the sixth variable-diameter wheel, and the variable-diameter wheel rotates relative to the input wheel; The planar helical grooves of the first and second variable-diameter wheels drive the first, second, third, fourth, fifth, and sixth sliders to shrink in the slide grooves of the first and second guide wheels, and the circle formed by the six sliders shrinks in diameter; The helical grooves of the third and fourth variable-diameter wheels drive the six sliders to shrink in the slide grooves of the third and fourth guide wheels, and the circle formed by the six sliders shrinks in diameter, the helical grooves of the fifth and sixth variable-diameter wheels drive the six sliders to shrink in the slide grooves of the fifth and sixth guide wheels, and the circle formed by the six sliders shrinks in diameter; Each guide wheel is evenly distributed with six slide grooves, and the included angle of the slide grooves is 60 degrees. The directions of the three groups of slide grooves of the first and second guide wheels, the third and fourth guide wheels, and the fifth and sixth guide wheels are all rotated by 20 degrees. The included angle between the 18 sliders is 20 degrees, and the 18 sliders together form a large circle with a total of 360 degrees; The left-hand screw rod is radially linked with the inner spline of the output wheel through the outer spline, and rotates synchronously. The left-hand screw rod drives the left-hand screw rod sleeve to rotate radially by axially sliding outward through the screw rod. The outer spline on the left-hand screw rod sleeve is radially linked with the inner spline of the seventh, eighth, ninth, tenth, eleventh, and twelfth variable-diameter wheels. The variable-diameter wheels rotate relative to the output wheel; The planar helical grooves of the seventh and eighth variable-diameter wheels drive the seventh, eighth, ninth, tenth, eleventh, and twelfth sliders to expand in the slide grooves of the seventh and eighth guide wheels, and the circle formed by the six sliders expands in diameter; The helical grooves of the ninth and tenth variable-diameter wheels drive the six sliders to expand in the slide grooves of the ninth and tenth guide wheels, and the circle formed by the six sliders expands in diameter. The helical grooves of the eleventh and twelfth variable-diameter wheels drive the six sliders to expand in the slide grooves of the eleventh and twelfth guide wheels, and the circle formed by the six sliders expands in diameter; Each guide wheel is evenly distributed with six slide grooves, and the included angle of the slide grooves is 60 degrees. The directions of the three groups of slide grooves of the seventh and eighth guide wheels, the ninth and tenth guide wheels, and the eleventh and twelfth guide wheels are all rotated by 20 degrees. The included angle between the 18 sliders is 20 degrees, and the 18 sliders together form a large circle with a total of 360 degrees; The input gear drives the input wheel to rotate. The multiple trapezoidal grooves on the sliders of the input wheel engage with the multiple trapezoidal grooves on the transmission ring. The multiple trapezoidal grooves on the sliders of the output wheel engage with the multiple trapezoidal grooves on the transmission ring. The tensioning wheel tensions the input wheel, the output wheel, and the transmission ring together through the first and second springs. The output wheel drives the output gear to rotate and output; The driving motor synchronously drives the right-hand screw rod and the left-hand screw rod to slide axially outward through the linkage block, drives the variable-diameter wheel to rotate relative to the input wheel, the circular diameter composed of the sliding blocks in the input wheel is reduced, the variable-diameter wheel rotates reversely relative to the output wheel, the circular diameter composed of the sliding blocks in the output wheel is expanded, the transmission ring is synchronously driven, and the rotating speed of the output wheel relative to the input wheel is increased; The right-hand screw rod and the left-hand screw rod slide inward, the circular diameter composed of the sliding blocks in the input wheel is expanded, the circular diameter composed of the sliding blocks in the output wheel is reduced, the transmission ring is synchronously driven, and the rotating speed of the output wheel relative to the input wheel is decreased; The input gear drives the input wheel to rotate, the driving motor synchronously drives the right-hand screw rod and the left-hand screw rod to slide axially through the linkage block, and drives the right-hand screw rod sleeve and the left-hand screw rod sleeve to rotate in the opposite direction in the radial direction; the input wheel and the variable-diameter wheel in the output wheel rotate in the opposite direction in the radial direction, the planar spiral groove of the variable-diameter wheel drives the sliding blocks to slide in the sliding groove of the guide wheel; the circular diameter composed of the sliding blocks in the input wheel is expanded, and the circular diameter composed of the sliding blocks in the output wheel is reduced; conversely, the input wheel is reduced, and the output wheel is expanded; the axial distance of the screw rod is controlled, the transmission ratio is continuously changed, and stepless speed regulation is realized. Advantages
[0005] The screw rod spiral variable-diameter stepless speed regulator has the following advantages: the input gear (100) drives the input wheel (1) to rotate, the driving motor (6) synchronously drives the right-hand screw rod (7) and the left-hand screw rod (8) to slide axially through the linkage block (9), and drives the right-hand screw rod sleeve (103) and the left-hand screw rod sleeve (203) to rotate in the opposite direction in the radial direction; the input wheel (1) and the variable-diameter wheel in the output wheel (2) rotate in the opposite direction in the radial direction, the planar spiral groove of the variable-diameter wheel drives the sliding blocks to slide in the sliding groove of the guide wheel; the circular diameter composed of the sliding blocks in the input wheel (1) is expanded, and the circular diameter composed of the sliding blocks in the output wheel (2) is reduced; conversely, the input wheel is reduced, and the output wheel is expanded; the axial distance of the screw rod is controlled, the transmission ratio is continuously changed, and stepless speed regulation is realized; the screw rod spiral variable-diameter stepless speed regulator uses the transmission ring (3) to replace the traditional steel belt / steel chain transmission, and uses the sliding block multi-group trapezoidal groove engagement transmission of the screw rod spiral variable-diameter structure to replace the traditional taper wheel compression to increase tension and speed change, and the screw rod spiral variable-diameter stepless speed regulator has the advantages of simple structure, durability, uniform speed change, high efficiency, large torque and high comprehensive performance. BRIEF DESCRIPTION OF DRAWINGS
[0006] Figure 1 It is the overall structure schematic diagram of the application; Figure 2 It is the partial sectional view of the application; Figure 3 It is Figure 2 the enlarged view of Figure 4 It is the partial structure schematic diagram of the application; Figures 5-7 It is the partial sectional view of the application; Figures 8-9 is a local structure schematic diagram of the present application; In the drawings: 1, input wheel; 2, output wheel; 3, transmission ring; 4, base; 5, tensioning wheel; 6, drive motor; 7, right-hand screw rod; 8, left-hand screw rod; 9, linkage block; 100, input gear; 101, first fixed disc; 102, second fixed disc; 103, right-hand screw rod sleeve; 111, first guide wheel; 112, second guide wheel; 113, third guide wheel; 114, fourth guide wheel; 115, fifth guide wheel; 116, sixth guide wheel; 121, first variable-diameter wheel; 122, second variable-diameter wheel; 123, third variable-diameter wheel; 124, fourth variable-diameter wheel; 125, fifth variable-diameter wheel; 126, sixth variable-diameter wheel; 131, first sliding block; 132, second sliding block; 133, third sliding block; 134, fourth sliding block; 135, fifth sliding block; 136, sixth sliding block; 200, output gear; 202, third fixed disc; 203, left-hand screw rod sleeve; 211, seventh guide wheel; 212, eighth guide wheel; 213, ninth guide wheel; 214, tenth guide wheel; 215, eleventh guide wheel; 216, twelfth guide wheel; 221, seventh variable-diameter wheel; 222, eighth variable-diameter wheel; 223, ninth variable-diameter wheel; 224, tenth variable-diameter wheel; 225, eleventh variable-diameter wheel; 226, twelfth variable-diameter wheel; 231, seventh sliding block; 232, eighth sliding block; 233, ninth sliding block; 234, tenth sliding block; 235, eleventh sliding block; 236, twelfth sliding block; 501, first spring; 502, second spring. DETAILED DESCRIPTION
[0007] The drawings in the examples of the present application will be used to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.
[0008] As Figures 1-8 shown, the present application provides a technical solution: the first guide wheel 111, the second guide wheel 112, the third guide wheel 113, the fourth guide wheel 114, the fifth guide wheel 115, and the sixth guide wheel 116 are fixed on the first fixed disc 101 and the second fixed disc 102, forming the input wheel 1. The right-hand screw rod 7 is radially linked with the inner spline of the input wheel 1 through the outer spline, rotates synchronously, and drives the right-hand screw rod sleeve 103 to radially rotate through the axial sliding of the screw rod. The right-hand screw rod sleeve 103 is radially linked with the inner spline of the first variable-diameter wheel 121, the second variable-diameter wheel 122, the third variable-diameter wheel 123, the fourth variable-diameter wheel 124, the fifth variable-diameter wheel 125 and the sixth variable-diameter wheel 126 through the outer spline, and the variable-diameter wheels rotate relative to the input wheel 1; The planar helical grooves of the first variable-diameter wheel 121 and the second variable-diameter wheel 122 drive the first slider 121, the second slider 122, the third slider 123, the fourth slider 124, the fifth slider 125 and the sixth slider 126 to shrink in the slide grooves of the first guide wheel 111 and the second guide wheel 112, and the diameter of the circle composed of the six sliders is reduced; The helical grooves of the third variable-diameter wheel 123 and the fourth variable-diameter wheel 124 drive the six sliders to shrink in the slide grooves of the third guide wheel 113 and the fourth guide wheel 114, and the diameter of the circle composed of the six sliders is reduced. The helical grooves of the fifth variable-diameter wheel 125 and the sixth variable-diameter wheel 126 drive the six sliders to shrink in the slide grooves of the fifth guide wheel 115 and the sixth guide wheel 116, and the diameter of the circle composed of the six sliders is reduced; Each guide wheel is averagely distributed with six slide grooves, and the included angle of the slide grooves is 60 degrees. The directions of the slide grooves of the first guide wheel 111 and the second guide wheel 112, the third guide wheel 113 and the fourth guide wheel 114, and the fifth guide wheel 115 and the sixth guide wheel 116 are all rotated by 20 degrees. The included angle between the 18 sliders is 20 degrees, and the 18 sliders together form a large circle with a total angle of 360 degrees. The left-hand screw rod 8 is radially linked with the inner spline of the output wheel 2 through the outer spline, rotates synchronously, and drives the left-hand screw rod sleeve 203 to radially rotate through the axial sliding of the screw rod. The outer spline on the left-hand screw rod sleeve 203 is radially linked with the inner spline of the seventh variable-diameter wheel 221, the eighth variable-diameter wheel 222, the ninth variable-diameter wheel 223, the tenth variable-diameter wheel 224, the eleventh variable-diameter wheel 225 and the twelfth variable-diameter wheel 226, and the variable-diameter wheels rotate relative to the output wheel 2; The planar helical grooves of the seventh variable-diameter wheel 221 and the eighth variable-diameter wheel 222 drive the seventh slider 231, the eighth slider 232, the ninth slider 233, the tenth slider 234, the eleventh slider 235 and the twelfth slider 236 to expand in the slide grooves of the seventh guide wheel 211 and the eighth guide wheel 212, and the diameter of the circle composed of the six sliders is expanded; The helical grooves of the ninth variable-diameter wheel 223 and the tenth variable-diameter wheel 224 drive the six sliders to expand in the slide grooves of the ninth guide wheel 213 and the tenth guide wheel 214, and the diameter of the circle composed of the six sliders is expanded. The helical grooves of the eleventh variable-diameter wheel 225 and the twelfth variable-diameter wheel 226 drive the six sliders to expand in the slide grooves of the eleventh guide wheel 215 and the twelfth guide wheel 216, and the diameter of the circle composed of the six sliders is expanded; Each guide wheel is averagely provided with 6 sliding grooves with an included angle of 60 degrees, the directions of the sliding grooves of the seventh guide wheel 211 and the eighth guide wheel 212, the ninth guide wheel 213 and the tenth guide wheel 214, and the eleventh guide wheel 215 and the twelfth guide wheel 216 are all rotated by 20 degrees, the included angles between the 18 sliding blocks are all 20 degrees, and the 18 sliding blocks together form a large circle with 360 degrees; The input gear 100 drives the input wheel 1 to rotate, the plurality of trapezoidal grooves on the sliding blocks on the input wheel 1 engage with the plurality of trapezoidal grooves on the transmission ring 3, the plurality of trapezoidal grooves on the sliding blocks on the output wheel 2 engage with the plurality of trapezoidal grooves on the transmission ring 3, and the tension wheel 5 tensions the input wheel 1, the output wheel 2 and the transmission ring 3 together through the first spring 501 and the second spring 502, and the output wheel 2 drives the output gear 200 to rotate and output; The driving motor 6 synchronously drives the right-hand screw rod 7 and the left-hand screw rod 8 to slide axially outward through the linkage block 9, the driving variable-diameter wheel rotates relative to the input wheel 1, the diameter of the circle formed by the sliding blocks in the input wheel 1 is reduced, the driving variable-diameter wheel rotates in the opposite direction relative to the output wheel 2, the diameter of the circle formed by the sliding blocks in the output wheel 2 is expanded, the transmission ring 3 is synchronously driven, and the output wheel 2 rotates faster than the input wheel 1; The right-hand screw rod 7 and the left-hand screw rod 8 slide inward, the diameter of the circle formed by the sliding blocks in the input wheel 1 is expanded, the diameter of the circle formed by the sliding blocks in the output wheel 2 is reduced, the transmission ring 3 is synchronously driven, and the output wheel 2 rotates slower than the input wheel 1; The input gear 100 drives the input wheel 1 to rotate, the driving motor 6 synchronously drives the right-hand screw rod 7 and the left-hand screw rod 8 to slide axially through the linkage block 9, and the right-hand screw rod sleeve 103 and the left-hand screw rod sleeve 203 rotate in the opposite direction; the input wheel 1 and the variable-diameter wheel in the output wheel 2 rotate in the opposite direction, the planar helical grooves of the variable-diameter wheel drive the sliding blocks to slide in the sliding grooves of the guide wheels; the diameter of the circle formed by the sliding blocks in the input wheel 1 is expanded, and the diameter of the circle formed by the sliding blocks in the output wheel 2 is reduced; conversely, the input wheel is reduced, and the output wheel is expanded; the axial distance of the screw rod is controlled, the transmission ratio is continuously changed to realize stepless speed regulation.
[0009] The above is only a preferred embodiment of the present application, and is not limited to the scope of protection of the present application. Various modifications and applications according to the above examples are within the scope of the technical solution.
Claims
1. A screw spindle screw pitch variable continuously variable transmission, characterized by: The first guide wheel (111), the second guide wheel (112), the third guide wheel (113), the fourth guide wheel (114), the fifth guide wheel (115) and the sixth guide wheel (116) are fixed on the first fixed disc (101) and the second fixed disc (102) to form the input wheel (1); The right-hand screw rod (7) is radially linked with the inner spline of the input wheel (1) through the outer spline, and rotates synchronously, the right-hand screw rod (7) drives the right-hand screw rod sleeve (103) to radially rotate through the axial sliding of the screw rod, the right-hand screw rod sleeve (103) is radially linked with the first variable-diameter wheel (121), the second variable-diameter wheel (122), the third variable-diameter wheel (123), the fourth variable-diameter wheel (124), the fifth variable-diameter wheel (125) and the sixth variable-diameter wheel (126) through the outer spline and the inner spline of the variable-diameter wheel, and the variable-diameter wheel rotates relative to the input wheel (1); The planar helical grooves of the first variable-diameter wheel (121) and the second variable-diameter wheel (122) drive the first slider (121), the second slider (122), the third slider (123), the fourth slider (124), the fifth slider (125) and the sixth slider (126) to shrink along the sliding grooves of the first guide wheel (111) and the second guide wheel (112), and the diameter of the circle formed by the six sliders is reduced; The helical grooves of the third variable-diameter wheel (123) and the fourth variable-diameter wheel (124) drive the six sliders to shrink along the sliding grooves of the third guide wheel (113) and the fourth guide wheel (114), and the diameter of the circle formed by the six sliders is reduced, and the helical grooves of the fifth variable-diameter wheel (125) and the sixth variable-diameter wheel (126) drive the six sliders to shrink along the sliding grooves of the fifth guide wheel (115) and the sixth guide wheel (116), and the diameter of the circle formed by the six sliders is reduced; Each guide wheel is evenly distributed with six sliding grooves, the included angle of the sliding grooves is 60 degrees, the included angle between the 18 sliders is 20 degrees, and the 18 sliders together form a large circle with 360 degrees; The left-hand screw rod (8) is radially linked with the inner spline of the output wheel (2) through the outer spline, and rotates synchronously, the left-hand screw rod (8) drives the left-hand screw rod sleeve (203) to radially rotate through the axial sliding of the screw rod, the outer spline of the left-hand screw rod sleeve (203) is radially linked with the seventh variable-diameter wheel (221), the eighth variable-diameter wheel (222), the ninth variable-diameter wheel (223), the tenth variable-diameter wheel (224), the eleventh variable-diameter wheel (225) and the twelfth variable-diameter wheel (226) through the inner spline of the variable-diameter wheel, and the variable-diameter wheel rotates relative to the output wheel (2); The planar helical grooves of the seventh variable-diameter wheel (221) and the eighth variable-diameter wheel (222) drive the seventh slider (231), the eighth slider (232), the ninth slider (233), the tenth slider (234), the eleventh slider (235) and the twelfth slider (236) to expand along the sliding grooves of the seventh guide wheel (211) and the eighth guide wheel (212), and the diameter of the circle formed by the six sliders is expanded; The spiral grooves of the ninth variable-diameter wheel (223) and the tenth variable-diameter wheel (224) drive six sliders to expand outward along the sliding grooves of the ninth guide wheel (213) and the tenth guide wheel (214), and the circle formed by the six sliders expands in diameter; the spiral grooves of the eleventh variable-diameter wheel (225) and the twelfth variable-diameter wheel (226) drive six sliders to expand outward along the sliding grooves of the eleventh guide wheel (215) and the twelfth guide wheel (216), and the circle formed by the six sliders expands in diameter; Each guide wheel is evenly distributed with six sliding grooves, and the included angle of the sliding grooves is 60 degrees; the directions of the sliding grooves of the seventh guide wheel (211) and the eighth guide wheel (212), the ninth guide wheel (213) and the tenth guide wheel (214), and the eleventh guide wheel (215) and the twelfth guide wheel (216) are all rotated by 20 degrees; the included angle between the 18 sliders is 20 degrees, and the 18 sliders together form a large circle with 360 degrees; The input gear (100) drives the input wheel (1) to rotate, the multiple trapezoidal grooves on the sliders on the input wheel (1) engage with the multiple trapezoidal grooves on the transmission ring (3), the multiple trapezoidal grooves on the sliders on the output wheel (2) engage with the multiple trapezoidal grooves on the transmission ring (3), the tensioning wheel (5) tensions the input wheel (1), the output wheel (2), and the transmission ring (3) together through the first spring (501) and the second spring (502), and the output wheel (2) drives the output gear (200) to rotate and output; The driving motor (6) synchronously drives the right-hand screw rod (7) and the left-hand screw rod (8) to slide axially outward through the linkage block (9), drives the variable-diameter wheel to rotate relative to the input wheel (1), the circle formed by the sliders in the input wheel (1) shrinks in diameter, drives the variable-diameter wheel to rotate in the opposite direction relative to the output wheel (2), the circle formed by the sliders in the output wheel (2) expands in diameter, the transmission ring (3) synchronously transmits, and the output wheel (2) rotates faster relative to the input wheel (1); The right-hand screw rod (7) and the left-hand screw rod (8) slide inward, the circle formed by the sliders in the input wheel (1) expands in diameter, the circle formed by the sliders in the output wheel (2) shrinks in diameter, the transmission ring (3) synchronously transmits, and the output wheel (2) rotates slower relative to the input wheel (1); The input gear (100) drives the input wheel (1) to rotate, the driving motor (6) synchronously drives the right-hand screw rod (7) and the left-hand screw rod (8) to slide axially through the linkage block (9), and drives the right-hand screw rod sleeve (103) and the left-hand screw rod sleeve (203) to rotate in opposite directions in the radial direction; the variable-diameter wheels in the input wheel (1) and the output wheel (2) rotate in opposite directions in the radial direction, the planar spiral grooves of the variable-diameter wheels drive the sliders to slide along the sliding grooves of the guide wheels; the circle formed by the sliders in the input wheel (1) expands in diameter, and the circle formed by the sliders in the output wheel (2) shrinks in diameter; conversely, the input wheel shrinks, and the output wheel expands; by controlling the axial distance of the screw rods, the transmission ratio is continuously changed to achieve stepless speed regulation.