Continuously Variable Transmission with Side Speed Regulating Lead Screw

Abstract

The invention relates to a continuously variable transmission with side speed regulating lead screw, and it comprises: a housing, a driving flat disc system, a power input system, a middle flat disc system, a power output system, a compaction system, a speed regulating ratio system of the middle flat disc, and serial and parallel structures. Since the previously most successful continuously variable transmission is the CVT continuously variable transmission, such continuously variable transmission transmits power depending on the conical disc and steel belt, and the limitation of the continuously variable transmission restrains the extensive application of such continuously variable transmission, whereas the continuously variable transmission of the invention transmits power depending on the mutual compaction between the driving flat disc and the middle flat disc as well as between the middle flat disc and the driven flat disc. The invention aims to solve the problem of too small transmission torque existing in previous continuously variable transmissions, and it realizes the objective of regulating the speed ratio by the movement of the middle flat disc up and down.

Claims

1. A continuously variable transmission with side speed regulating lead screw, characterized in that: the lead screw nut of the middle flat disc on one part of the middle flat disc bracket is matched with the lead screw of the middle flat disc, the other part of the middle flat disc bracket is matched with the middle flat disc through the middle flat disc bearing, and the lead screw of the middle flat disc is arranged on the side of the middle flat disc.

2. The continuously variable transmission according to claim 1, characterized in that: the hydraulic compaction system comprises a hydraulic lever bracket which is fixed and connected with the output shaft, when the hydraulic cylinder is compressed, one end of the hydraulic lever pushes against the sliding driven flat disc, the hole in the middle of the hydraulic lever is hinged with the hydraulic lever bracket, the hydraulic plate pulls the other end of the hydraulic lever, the output shaft passes through the center hole of the hydraulic plate, and the hydraulic plate can slide on the output shaft relative to it.

3. The continuously variable transmission according to claim 1, characterized in that: There are driven flat disc grooves on the driven flat discs. Owing to the existence of the driven flat disc grooves, the other end of the middle flat disc can move in the driven flat disc grooves. When the driven flat disc grooves are deep enough, as the middle flat disc gets across the driven flat disc grooves, the compaction system is decompressed, and the middle flat disc can also span over the bracket beam of the driving flat disc without moving the sliding driven flat disc; when the driven flat disc grooves are not deep enough, as the middle flat disc gets across the driven flat disc grooves, the compaction system is decompressed, and the middle flat disc can span over the bracket beam of the driving flat disc only when the sliding driven flat disc is moved towards the compaction system for a certain distance, but the moving distance of the sliding driven flat disc shall be less than that when there is no sliding driven flat disc groove on the sliding driven flat disc.

4. The continuously variable transmission according to claim 1, characterized in that: the continuously variable transmission has the intermediate gear of the driving flat discs which can be matched with two driving flat disc gears, respectively, and the intermediate gear of the driving flat disc can be matched with the input shaft gear at the same time of matching with one driving flat disc gear.

5. The continuously variable transmission according to claim 1, characterized in that: The continuously variable transmission can have two middle flat discs in parallel, as well as more than two middle flat discs in parallel.

6. The continuously variable transmission according to claim 1, characterized in that: The continuously variable transmission can have two middle flat discs in series, as well as more than two middle flat discs in series.

7. The continuously variable transmission according to claim 1, characterized in that: the speed regulating ratio system of the middle flat disc comprises: the threaded part of the lead screw of the middle flat disc is matched with the lead screw nut of the middle flat disc on the middle flat disc bracket, the lead screw nut of the middle flat disc is fixed and connected or integrated with the middle flat disc bracket, and along with the rotation of the lead screw of the middle flat disc, the lead screw nut of the middle flat disc drives the middle flat disc bracket and the middle flat disc to move back and forth along with the axis of the lead screw of the middle flat disc to realize the process of speed regulating ratio for the middle flat disc.

8. The continuously variable transmission according to claim 1, characterized in that: the speed regulating ratio system of the middle flat disc also comprises: The lead screw gear of the middle flat disc is fixed on the lead screw of the middle flat disc, the lead screw gear of the middle flat disc is matched with the regulating shaft gear of the middle flat disc gear on the regulating shaft of the middle flat disc, the regulating shaft gear of the middle flat disc is fixed and connected with the regulating shaft of the middle flat disc, the regulating shaft of the middle flat disc is arranged vertical to the axis of the lead screw of the middle flat disc, the regulating shaft of the middle flat disc is arranged in parallel with the output shaft, and the speed regulating pinion of the middle flat disc on the regulating shaft of the middle flat disc is fixed and connected with the regulating shaft of the middle flat disc. The speed regulating pinions of each flat disc are matched with the speed regulating gearwheel of the same flat disc.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The figures are explained below:

[0022] FIG. 1 is the A-A section view of FIG. 5 and the structural drawing of the continuously variable transmission, and the middle flat disc is in the forward position of the power output shaft;

[0023] FIG. 2 is the B-B section view of FIG. 5 and the structural drawing of the continuously variable transmission, and the position of the input shaft can be seen in the figure;

[0024] FIG. 3 is the section view of the serial structure of two continuously variable

[0025] Specification transmissions;

[0026] FIG. 4 is the matching drawing of the middle flat disc with the lead screw of the middle flat disc, and the middle flat disc is in the farthest distance from the output shaft;

[0027] FIG. 5 is the matching drawing of the middle flat disc with the lead screw of the middle flat disc matching drawing, and the middle flat disc is in the nearest distance from the output shaft;

[0028] FIG. 6 is the sketch map of Scheme 1 for the structural system of input shaft gear, intermediate gear of the driving flat disc and driving flat disc gear in the structure of three middle flat discs in parallel;

[0029] FIG. 7 is the sketch map of Scheme 2 for the structural system of input shaft gear, intermediate gear of the driving flat disc and driving flat disc gear in the structure of three middle flat discs in parallel;

[0030] FIG. 8 is the sketch map of Scheme 3 for the structural system of input shaft gear, intermediate gear of the driving flat disc and driving flat disc gear in the structure of three middle flat discs in parallel;

[0031] FIG. 9 is the second structural sketch map of Scheme 1 for the structural system of input shaft gear, intermediate gear of the driving flat disc and driving flat disc gear in the structure of three middle flat discs in parallel;

[0032] FIG. 10 is the layout drawing that a middle flat disc bracket and a lead screw of the middle flat disc is arranged on the each middle flat disc, and the axis of the middle flat disc bracket is vertical to the axis of the output shaft;

[0033] FIG. 11 is the layout drawing that a middle flat disc bracket and lead screw of the middle flat disc are arranged on each middle flat disc, the axis of the middle flat disc bracket is in a certain angle with the axis of the output shaft;

[0034] FIG. 12 is the layout drawing that two middle flat disc brackets and two lead screw of the middle flat discs are arranged on the each middle flat disc, and the axes of the middle flat disc brackets are vertical to the axis of the output shaft;

[0035] FIG. 13 is the layout drawing that two middle flat disc brackets and two lead screw of the middle flat discs are arranged on the each middle flat disc, and the axes of the middle flat disc brackets are in a certain angle with the axis of the output shaft;

[0036] FIG. 14 is the D-D section view of FIG. 16, as well as the structural drawing that the lead screw of the middle flat disc is a ball lead screw and the lead screw nut on the middle flat disc bracket is a ball;

[0037] FIG. 15 is the E-E section view of FIG. 14, as well as the structural drawing that the lead screw of the middle flat disc is a ball lead screw, the lead screw nut on the middle flat disc bracket is a ball nut, and the external loop orbit is indicated;

[0038] FIG. 16 is the structural drawing that the middle flat disc has no center hole, the middle flat disc bearing is installed on the center shaft of the middle flat disc, the center shaft of the middle flat disc is fixed and connected or integrated with the middle flat disc;

[0039] FIG. 17 is the structural drawing that the double-layer bearing of the middle flat disc is in the center hole of the middle flat disc;

[0040] FIG. 18 is the structural drawing that the single-layer bearing of the middle flat disc is in the center hole of the middle flat disc;

[0041] FIG. 19 is the structural drawing that the double-layer bearing of the middle flat disc is in the center hole of the middle flat disc, and the middle flat disc is thickened;

[0042] FIG. 20 is the top view of FIG. 16;

[0043] FIG. 21 is the top view of FIG. 17;

[0044] FIG. 22 is the top view of FIG. 18;

[0045] FIG. 23 is the top view of FIG. 19;

[0046] FIG. 24 shows the phase of forward and reverse conversion that the middle flat disc is closest to the bracket beam of the driving flat disc;

[0047] FIG. 25 shows the phase of forward and reverse conversion from the middle flat disc to the top of the middle beam of the driving flat disc;

[0048] FIG. 26 shows the phase of forward and reverse conversion that middle flat disc passes over the top of the middle beam of the driving flat disc;

[0049] FIG. 27 shows the phase of forward and reverse conversion that middle flat disc passes over the middle beam of the driving flat disc;

[0050] FIG. 28 shows that the middle flat disc passes over the middle beam of the driving flat disc and starts to reverse;

[0051] FIG. 29 is the structural drawing for Position 2 of the regulating shaft end of the middle flat disc, showing the matching relations of the speed regulating pinion of the middle flat disc, the regulating shaft end of the middle flat disc and the regulating shaft end gear of the middle flat disc with the speed regulating gearwheel of the middle flat disc;

[0052] FIG. 30 is the left view of FIG. 31;

[0053] FIG. 31 is the structural drawing for the half bracket I of the driving flat disc;

[0054] FIG. 32 is the right view of FIG. 31;

[0055] FIG. 33 is the left view of FIG. 34;

[0056] FIG. 34 is the structural drawing for the half bracket II of the driving flat disc;

[0057] FIG. 35 is the left view of FIG. 34;

[0058] FIG. 36 is the component matching relation drawing of the half bracket I of the driving flat disc and the half bracket II of the driving flat disc with the driving flat disc;

[0059] FIG. 37 is the matching relation drawing of the half bracket II of the driving flat disc with the driving flat disc gear, the input shaft gear and the intermediate gear of the driving flat disc;

[0060] FIG. 38 is the matching relation drawing of the intermediate gear of the driving flat disc with the half bracket I of the driving flat disc and the half bracket II of the driving flat disc;

[0061] FIG. 39 is the structural drawing of the transmission with middle flat discs in parallel, and the middle flat disc is in the nearest position to the output shaft;

[0062] FIG. 40 the structural drawing of the transmission with middle flat discs in parallel, in the structural drawing, Scheme 1 for the structural system of input shaft gear, intermediate gear of the driving flat disc and driving flat disc gear: the input shaft gear is matched with two driving flat disc gears, and the two driving flat disc gears are matched with another two driving flat disc gears through the intermediate gear of the driving flat disc, respectively;

[0063] FIG. 41 is the structural drawing of Position 2 of the regulating shaft end of the middle flat disc in the transmission with four middle flat discs in parallel, showing the matching relations of the speed regulating pinion of the middle flat disc, the regulating shaft end of the middle flat disc and the regulating shaft end gear of the middle flat disc with the speed regulating gearwheel of the middle flat disc;

[0064] FIG. 42 is the structural drawing of the transmission with four middle flat discs in parallel. In the structural drawing, Scheme 2 for the structural system of input shaft gear, intermediate gear of the driving flat disc and driving flat disc gear; The input shaft gear is matched with one driving flat disc gear, and two neighboring driving flat disc gears are matched with the intermediate gear of the driving flat disc arranged between them;

[0065] FIG. 43 is the structural drawing of the transmission with four middle flat discs in parallel, and the middle flat disc is the farthest position from the output shaft;

[0066] FIG. 44 is the C-C section view of FIG. 46, and the middle flat disc is in the forward position;

[0067] FIG. 45 is the structural drawing of the transmission with five middle flat discs in

[0068] Specification parallel, and the middle flat disc is in the forward position;

[0069] FIG. 46 is the structural drawing of the transmission with five middle flat discs in parallel, and the middle flat disc is the farthest position from the output shaft;

[0070] FIG. 47 shows Scheme 2 for the structural system of input shaft gear, intermediate gear of the driving flat disc and driving flat disc gear in the structure of the continuously variable transmission with five middle flat discs in parallel: the input shaft gear is matched with one driving flat disc gear; and two neighboring driving flat disc gears are matched with the intermediate gear of the driving flat disc arranged between them;

[0071] FIG. 48 is the structural drawing of the transmission with five middle flat discs in parallel, and the middle flat disc is in the nearest position to the output shaft;

[0072] FIG. 49 shows Scheme 1 for the structural system of input shaft gear, intermediate gear of the driving flat disc and driving flat disc gear in the structure of the continuously variable transmission with five middle flat discs in parallel: the input shaft gear is matched with two driving flat disc gears, the two driving flat disc gears are matched with another two driving flat disc gears through the intermediate gear of the driving flat disc, respectively, and the fifth driving flat disc gear is matched with one neighboring driving flat disc gear through the intermediate gear of the driving flat disc;

[0073] In the figures: 1Speed regulating pinion of the middle flat disc; 2Bracket beam of the driving flat disc; 3Lead screw gear of the middle flat disc; 4Lead screw of the middle flat disc; 5Regulating shaft of the middle flat disc gear; 6Regulating shaft of the middle flat disc; 7Driving flat disc key; 8Driving flat disc nut; 9Mandrel bolt of the driving flat disc; 10Half bracket I of the driving flat disc; 11Fixed driven flat disc; 12Middle flat disc bracket; 13Fixing snap ring of the fixed driven flat disc; 14Driven flat disc groove; 15Hydraulic cylinder block; 16Middle flat disc; 17Hinge of the hydraulic lever; 18Hydraulic lever; 19Hinging base of the hydraulic lever; 20Hydraulic plate; 21Hydraulic lever bracket; 22Hydraulic plate spring; 23Positioning pin of the hydraulic lever bracket; 24Oil way communicator; 25Oil inlet of the hydraulic cylinder; 26Driving flat disc mandrel I; 27Middle driven flat disc; 28Hydraulic lever block; 29Driving flat disc; 30Driving flat disc gear; 31Hydraulic oil way; 32bracket bolt of the driving flat disc; 33Middle fiat disc bearing; 34Driving flat disc mandrel II; 35Half bracket II of the driving flat disc; 36Output shaft; 37Speed regulating gearwheel of the middle flat disc; 38Sliding driven flat disc; 39lead screw for the bearing seat of the middle flat disc; 40Intermediate gear of the driving flat disc; 41Input shaft gear; 42Input shaft; 43Housing; 44bracket key groove of the driving flat disc; 45Intermediate gear of the driving flat disc shaft; 46Regulating shaft end of the middle flat disc; 47Regulating shaft end gear of the middle flat disc; 48Ball of the ball lead screw; 49External loop channel of ball nut; 50Key groove of the housing; 51Bearing seat of the input shaft; 52Lead screw nut of the middle flat disc.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0074] It can be seen in FIG. 1, FIG. 2, FIG. 3, FIG. 4, FIG. 9, FIG. 24, FIG. 25, FIG. 26, FIG. 27, FIG. 28, FIG. 29, FIG. 30, FIG. 31, FIG. 32, FIG. 33, FIG. 34, FIG. 35, FIG. 36, FIG. 37 and FIG. 38, driving flat disc system: A pair of driving flat discs 29 are matched with the driving flat disc gear 30 through the driving flat disc key 7 and tightened by the driving flat disc nut 8, the bracket beams 2 of the driving flat disc are arranged on both the half bracket I 10 of the driving flat disc and the half bracket II 35 of the driving flat disc, the driving flat disc mandrel I 26 is arranged in the middle of the bracket beam 2 of the driving flat disc on the half bracket I 10 of the driving flat disc, the driving flat disc mandrel II 34 is arranged in the middle of the bracket beam 2 of the driving flat disc on the half bracket II 35 of the driving flat disc, the half bracket I 10 of the driving flat disc and the half bracket II 35 of the driving flat disc are tightened and fixed with the bracket bolt of the driving flat disc 32 through the mandrel bolt 9 of the driving flat disc, and the driving flat disc is in running fit with the driving flat disc mandrel I 10 and the driving flat disc mandrel II 35 through bearings. The lowest point of the bracket beam 2 of the driving flat disc is higher than the plane of the driving flat disc 29.

[0075] Power output system: The driven flat disc grooves 14 are arranged on the driven flat discs (including the fixed driven flat disc 11, the middle driven flat disc 27 and the sliding driven flat disc 38), the output shaft 36 passes through the center hole of the fixed driven flat disc 11, the fixed driven flat disc 11 is fixed and connected with the output shaft 36, the sliding driven flat disc 38 and the output shaft 36 can relatively slide but can't relatively rotate, the output shaft 36 passes through the center hole of the sliding driven flat disc 11, the sliding driven flat disc 11 is fixed and connected with the hydraulic cylinder block 15, and the power is transmitted out of the transmission by the output shaft 36.

[0076] Forward and reverse conversions: 1. The forward and reverse conversions of the continuously variable transmission shall be completed by the middle flat disc 16 spanning from one side of the bracket beam 2 of the driving flat disc to the other side of the bracket beam 2 of the driving flat disc, namely, along with the rotation of the lead screw 4 of the middle flat disc, the middle flat disc 16 is moved to the position close to the bracket beam 2 of the driving flat disc (see FIG. 24); 2. One end of the middle flat disc 16 continues to move along the bevel of the bracket beam 2 of the driving flat disc, and it continues to move after reaching the top of the bracket beam 2 of the driving flat disc (see FIG. 25 and FIG. 26); 3. The other end of the middle flat disc 16 continues to move along the bevel of the driven flat disc grooves 14 of the driven flat discs (including the fixed driven flat disc 11, and the sliding driven flat disc 38 and the middle driven flat disc 27), so that the middle flat disc 16 can reach the other side of the bracket beam 2 of the driving flat disc (see FIG. 27 and FIG. 28); owing to the existence of the driven flat disc grooves 14, the other end of the middle flat disc can move in the driven flat disc grooves 14.

[0077] Structural scheme of the driven flat disc grooves 14: 1. When the driven flat disc grooves 14 are deep enough, as the middle flat disc 16 gets across the driven flat disc grooves 14, the compaction system is decompressed, and the middle flat disc 16 can also span over the bracket beam 2 of the driving flat disc without moving the sliding driven flat disc; 2. When the driven flat disc grooves 14 are not deep enough, as the middle flat disc gets across the driven flat disc grooves 14, the compaction system is decompressed, and the middle flat disc can span over the bracket beam 2 of the driving flat disc only when the sliding driven flat disc 38 is moved towards the compaction system for a certain distance, but the moving distance of the sliding driven flat disc 38 shall be less than that when there is no sliding driven flat disc groove 14 on the sliding driven flat disc 38, the continuously variable transmission can be made into smaller size, and the cross section of the bracket beam 2 of the driving flat disc can be made into bigger area. This kind of transmission can use the forward function but not use the reverse function.

[0078] Compaction system: The hydraulic compaction system comprises a hydraulic lever bracket 21 which is fixed and connected with the output shaft 36, and when the hydraulic cylinder is compressed, one end of the hydraulic lever 18 pushes against the sliding driven flat disc 38: one end of the hydraulic lever 18 is contacted with the sliding driven flat disc 38 through the hydraulic lever block 28; the hole in the middle of the hydraulic lever 18 is hinged with the hydraulic lever bracket 21, and the hydraulic plate 20 pulls the other end of the hydraulic lever 18: the hole at the other end of the hydraulic lever 18 can be hinged with one end of the hinge 17 of the hydraulic lever, and the other end of the hinge 17 of the hydraulic lever can be hinged with the hinging base 19 of the hydraulic lever, and the hinging base 19 of the hydraulic lever is fixed on the hydraulic plate 20; the output shaft 36 passes through the center hole of the hydraulic plate 20, and the hydraulic plate 20 can slide on the output shaft 36 relative to it.

[0079] Speed regulating ratio system of the middle flat disc: It is specified that the speed ratio is obtained by dividing the absolute value of input shaft 42 speed by the absolute value of output shaft 36 speed, the speed regulating ratio system of each middle flat disc 16: the lead screw 39 for the bearing seat of the middle flat disc is fixed and connected with the housing 43, one end of the lead screw 4 of the middle flat disc is installed on the lead screw 39 for the bearing seat of the middle flat disc through the bearing, the other end of the lead screw 4 of the middle flat disc is installed on the housing 43 through the bearing, the threaded part of the lead screw 4 of the middle flat disc is matched with the lead screw nut 52 of the middle flat disc on the middle flat disc bracket 12, the lead screw nut 52 of the middle flat disc is fixed and connected or integrated with the middle flat disc bracket 12, and along with the rotation of the lead screw 4 of the middle flat disc, the lead screw nut 52 of the middle flat disc drives the middle flat disc bracket 12 and the middle flat disc 16 to move back and forth along with the axis of the lead screw 4 of the middle flat disc to realize the process of speed regulating ratio for the middle flat disc 16. The lead screw gear 3 of the middle flat disc is fixed on the lead screw 4 of the middle flat disc, the lead screw gear 3 of the middle flat disc can be a worm gear, and the lead screw gear 3 of the middle flat disc, is matched with the regulating shaft 5 of the middle flat disc gear on the regulating shaft 6 of the middle flat disc; the regulating shaft 5 of the middle flat disc gear can be a worm, the regulating shaft 5 of the middle flat disc gear is fixed and connected with the regulating shaft 6 of the middle flat disc, the regulating shaft 6 of the middle flat disc is arranged vertical to the axis of the lead screw 4 of the middle flat disc, the regulating shaft 6 of the middle flat disc is arranged in parallel with the output shaft 36, and the speed regulating pinion 1 of the middle flat disc on the regulating shaft 6 of the middle flat disc is fixed and connected with the regulating shaft 6 of the middle flat disc.

[0080] Position 1 of the regulating shaft end 46 of the middle flat disc: The regulating shaft end 46 of the middle flat disc, is arranged on one speed, regulating pinion 1 of the middle flat disc (see FIG. 2);

[0081] Position 2 of the regulating shaft end 46 of the middle flat disc: The regulating shaft end 46 of the middle flat disc is separately matched with the gear 47 at the regulating shaft end of the middle flat disc, and the regulating shaft end 46 of the middle fiat disc is matched with the speed regulating gearwheel 37 of the middle flat disc (FIG. 29).

[0082] The speed regulating pinion 1 of the middle flat disc of the speed regulating ratio system of each middle flat disc 16 is matched with the same speed regulating gearwheel 37 of the middle flat disc, 1. In Position 1 of the regulating shaft end 46 of the middle flat disc: The speed regulating power is transmitted from the regulating shaft end 46 of the middle flat disc to one speed regulating pinion 1 of the middle flat disc and then transmitted to each of the rest of speed regulating pinions 1 of the middle flat discs through the speed regulating gearwheel 37 of the middle flat disc; 2. In Position 2 of the regulating shaft end 46 of the middle flat disc: The speed regulating power is transmitted to the speed regulating gearwheel 37 of the middle flat disc from the regulating shaft end 46 of the middle flat disc, and then transmitted to each of the rest of speed regulating pinions 1 of the middle flat discs by the speed regulating gearwheel 37 of the middle flat disc, and each speed regulating pinion 1 of the middle flat disc drives each middle flat disc 16 to move back and forth along the axis of the lead screw 4 of the middle flat disc through the speed regulating ratio system of each middle flat disc 16 to realize the regulation of speed ratio by the middle flat disc 16.

[0083] The bracket keys of the driving flat disc are added in the housing key groove 50 (see FIG. 4 and FIG. 5) and the bracket key groove 44 of the driving flat disc (see FIG. 30 and FIG. 32) on the housing 43, so that the driving flat disc bracket (including the half bracket I 10 of the driving flat disc and the half bracket II 35 of the driving flat disc) can only slide relative to the axis of the housing 43 but can't rotate.

[0084] It can be seen in FIG. 10, FIG. 11, FIG. 12, FIG. 13, FIG. 14, FIG. 15, FIG. 16, FIG. 17, FIG. 18, FIG. 19, FIG. 20, FIG. 21, FIG. 22 and FIG. 23, middle flat disc 16 system: the lead screw nut 52 of the middle flat disc at one end of the middle flat disc bracket 12 is matched with the lead screw 4 of the middle flat disc 4, the other end is matched with the middle flat disc 16 through the middle flat disc bearing, the lead screw 4 of the middle flat disc is arranged on the side of the middle flat disc 16, the lead screw nut 52 of the middle flat disc is integrated or fixed and connected with the middle flat disc bracket 12, and the middle flat disc 16 works between the driving flat disc 29 and the driven flat discs (including the fixed driven flat disc 11, the sliding driven flat disc 38 and the middle driven flat disc 27). The lead screw of the middle flat disc can be sliding lead screw, rolling lead screw (including ball lead screw and roller lead screw) and hydrostatic lead screw, and the matched lead screw nut 52 of the middle flat disc can be sliding screw nut, rolling screw nut (including ball nut and roller nut) and hydrostatic nut. Middle flat disc system: The lead screw nut 52 of the middle flat disc on one part of the middle flat disc bracket 12 is matched with the lead screw 4 of the middle flat disc, the other part of the middle flat disc bracket 12 is matched with the middle flat disc 16 through the middle flat disc bearing 33, the lead screw 4 of the middle flat disc is arranged on the side of the middle flat disc 16, the lead screw nut 52 of the middle flat disc is integrated or fixed and connected with the middle flat disc bracket 12, and the middle flat disc 16 works between the driving flat discs and the driven flat discs (including the fixed driven flat disc 11, the sliding driven flat disc 38 and the middle driven flat disc 27). The lead screw 4 of the middle flat disc can be sliding lead screw, rolling lead screw (including ball lead screw and roller lead screw) and hydrostatic lead screw; the matched lead screw nut of the middle flat disc can be sliding nut, rolling nut (including ball nut and roller nut) and hydrostatic nut.

Several schemes of the middle flat disc: 1. The middle flat disc bearing 55 is a double-layer bearing arranged in the center role of the middle flat disc 10 (see FIG. 17 and FIG. 21). 2. The middle flat disc bearing 55 is a single-layer bearing arranged in the center hole of the middle flat disc 10 (see FIG. 18 and FIG. 22). 3. The middle flat disc bearing 55 is a double-layer bearing arranged in the center role of the middle flat disc 10, and the middle flat disc 10 is thickened (see FIG. 19 and FIG. 23). 4. The middle flat disc 10 has no center hole, the middle flat disc bearing 55 is installed on the center shaft of the middle flat disc 10, and the center shaft of the middle flat disc 10 is fixed and connected or integrated with the middle flat disc 10 (see FIG. 16 and FIG. 20); Type 1 of the middle flat disc bracket 12, 1. Each middle flat disc 10 has one middle flat disc bracket 12 and one lead screw 6 of the middle flat disc 6, and the axis of the middle flat disc bracket 12 is vertical to the axis of the output shaft 37 (see FIG. 10); 2. Each middle flat disc 10 has one middle flat disc bracket 12 and one lead screw 6 of the middle flat disc, the axis of the middle flat disc bracket 12 is in a certain angle with the axis of the output shaft 37 (see FIG. 11); 3. Each middle flat disc 10 has two middle flat disc brackets 12 and two lead screws 6 of the middle flat disc, the axes of the middle flat disc brackets 12 are vertical to the axes of the output shaft 37 (see FIG. 12); 4. Each middle flat disc 10 has two middle flat disc brackets 12 and two lead screws 6 of the middle flat disc, and the axes of the middle flat disc brackets 12 are in a certain angle with the axes of the output shafts 37 (see FIG. 13).

[0085] It can be seen in FIG. 6, FIG. 7, FIG. 8 and FIG. 9, power input system: In the structure of three middle flat discs 16 in parallel, schemes for the structural system of input shaft gear 41, intermediate gear 40 of the driving flat disc and driving flat disc gear 30: 1. The input shaft gear 41 is matched with one driving flat disc gear 30, and each pair of neighboring driving flat disc gears 30 are matched with the same intermediate gear 40 of the driving flat disc (see FIG. 6 and FIG. 9); 2. Each pair of neighboring driving flat disc gear 30 are matched with the same intermediate gear 40 of the driving flat disc, and the input shaft gear 41 transmits power to each driving flat disc gear 30 through the intermediate gear 40 of the driving flat disc (see FIG. 7); 3. The input shaft gear 41 transmits the power to two driving flat disc gears 30 simultaneously, and one of the driving flat disc gears 30 then transmits the power to the other driving flat disc gear 30 through the intermediate gear 40 of the driving flat disc (see FIG. 8). This kind of continuously variable transmission has intermediate gear 40 of the driving flat discs which can be matched with two driving flat disc gears 30, respectively, and the intermediate gear 40 of the driving flat disc can be matched with the input shaft gear 41 at the same time of matching with one driving flat disc gear 30.

[0086] The position of middle flat disc 16 in FIG. 6 is the minimum reverse speed ratio; the position of middle flat disc 16 in FIG. 7 is the maximum reverse speed ratio; the position of middle flat disc 16 in FIG. 8 is the maximum forward speed ratio; the position of middle flat disc 16 in FIG. 9 is the minimum forward speed ratio.

[0087] It can be seen in FIG. 39, FIG. 40, FIG. 41, FIG. 42 and FIG. 43 that, in the continuously variable transmission with four middle flat discs 16 in parallel, except that the number of middle flat discs 16 is increased by than the number of middle flat discs 16 with three middle flat discs 16 in parallel, and the numbers of the rest of components matched with the middle flat disc 16 are also increased by accordingly.

[0088] It can be seen in FIG. 44, FIG. 45, FIG. 46, FIG. 47, FIG. 48 and FIG. 49, in the continuously variable transmission with five middle flat discs 16 in parallel, except that the number of middle flat discs 16 is increased by than the number of middle flat discs 16 with three middle flat discs 16 in parallel, and the numbers of the rest of components matched with the middle flat disc 16 are also increased by accordingly.

[0089] In the figures, parallel and serial structure: the number of middle flat discs 16 connected with the same driven flat disc (including the fixed driven flat disc 11, the middle driven flat disc 27 and the sliding driven flat disc 28) is considered as the number of parallel connections, the invention can have more than two (including two) middle flat discs 16 in parallel, the number of driving flat discs 29 is the same as the number of middle flat discs 16 in parallel, and the number of the speed regulating ratio systems of each middle flat disc 16 is also the same as the number of middle flat discs 16 in parallel; the structure between every two neighboring driven flat discs (including the fixed driven flat disc 11, the sliding driven flat disc 38 and the middle driven flat disc 27) is called as a transmission, more than two (including two) transmissions can be connected in series, and the number of transmissions in series is the number of serial connections for the continuously variable transmission. Manner of serial connection: Multiple transmissions in series share the same output shaft 36, multiple transmissions in series share the same input shaft 42, and the number of speed regulating ratio systems for each middle flat disc 16 is also the same as the number of middle flat discs 16 in

[0090] The work principles of the continuously variable transmission are explained by combining with the figures:

[0091] 1. Work principle of power transmission: Power enters the continuously variable transmission from the input shaft 42, and the power is transmitted to the input shaft gear 41 through the input shaft 42. Power transmission route according to the schemes for the structural system of input shaft gear 41, intermediate gear 40 of the driving flat disc and driving flat disc gear 30: 1. The input shaft gear 41 transmits the power to one driving flat disc gear 30, and the driving flat disc gear 30 then transmits the power to other driving flat disc gears 30 through the intermediate gear 40 of the driving flat disc; 2. Each pair of neighboring driving flat disc gears 30 are connected by one intermediate gear 40 of the driving flat disc, the input shaft gear 41 transmits the power to each driving flat disc gear 30 through the intermediate gear 40 of the driving flat disc. 3. The input shaft gear 41 transmits the power to two driving flat disc gears 30 simultaneously, and then one of the driving flat disc gears 30 transmits the power to the other driving flat disc gear 30 through the intermediate gear 40 of the driving flat disc. The driving flat disc gear 30 then transmits the power to the driving flat discs 29, when the hydraulic cylinder is compressed, the driving flat discs 29 transmit the power to the middle flat disc 16 by friction, the middle flat disc 16 also transmits the power to the fixed driven flat disc 11 and the sliding driven flat disc 38 through friction, the power is transmitted to the output shaft 36 through the driven flat discs, and the power is transmitted out of the transmission by the output shaft 36.

[0092] 2. Work principle of the hydraulic cylinder: After the hydraulic oil is pressurized, on the one hand, the oil pressure acts on the sliding driven flat disc 38; on the other hand, the oil pressure acts on the hydraulic plate 20, the hydraulic plate 20 pulls the hinge 17 of the hydraulic lever through the hinging base 19 of the hydraulic lever, then the hinge 17 of the hydraulic lever pulls the hydraulic lever 18, and the hydraulic lever 18 compresses the sliding driven flat disc 38 through the hydraulic lever block 28 by taking the hydraulic lever bracket 21 as the fulcrum.

[0093] 3. Work principle for speed regulating ratio of middle flat disc 16: It is specified that the speed ratio is obtained by dividing the absolute value of the input shaft 42 speed by the absolute value of the output shaft 36 speed. The speed regulating power enters the continuously variable transmission from the regulating shaft end 46 of the middle flat disc, 1. In the structure that the regulating shaft end 46 of the middle flat disc is fixed on the regulating shaft 6 of the middle flat disc, the speed regulating power is transmitted from the regulating shaft end 461 of the middle flat disc to one speed regulating pinion of the middle flat disc, then the speed regulating pinion 1 of the middle flat disc transmits the speed regulating power to the speed regulating gearwheel 37 of the middle flat disc, the speed regulating gearwheel 37 of the middle flat disc then transmits it to each of the rest of speed regulating pinions 1 of the middle flat disc, and each speed regulating pinion 1 of the middle flat disc drives each middle flat disc 16 to move back and forth along the axis of the lead screw 4 of the middle flat disc through the speed regulating ratio system of each middle flat disc 16 to realize the regulation of the speed ratio of the middle flat disc 16; 2. In the structure that the regulating shaft end 46 of the middle flat disc is separately fixed and connected with the regulating shaft end 47 of the middle flat disc gear, the regulating shaft end 47 of the middle flat disc gear is matched with the speed regulating gearwheel 37 of the middle flat disc, the speed regulating power is transmitted from the regulating shaft end 46 of the middle flat disc to the speed regulating gearwheel 37 of the middle flat disc through the regulating shaft end 47 of the middle flat disc gear, the speed regulating gearwheel 37 of the middle flat disc then transmits it to each of the rest of speed regulating pinions 1 of the middle flat disc, each speed regulating pinion 1 of the middle flat disc drives each middle flat disc 16 to move back and forth along the axis of the lead screw 4 of the middle flat disc through the speed regulating ratio system of each middle flat disc 16 to realize the regulation of speed ratio of the middle flat disc 16.