A variable speed control structure and a continuously variable transmission

Abstract

This invention discloses a variable speed control structure and a continuously variable transmission (CVT). The variable speed control structure includes an output shaft and an output moving cone disk axially movably mounted on the output shaft. A first speed regulating component, which can rotate relative to the output moving cone disk, is coaxially disposed on the side of the output moving cone disk away from the cone surface. A second speed regulating component, which can rotate relative to the output shaft, is coaxially disposed on the output shaft. Both the first and second speed regulating components are rotating bodies and are engaged by a helical pushing structure. The invention also includes a speed regulating shaft parallel to the output shaft, which has at least two active speed regulating gears. The diameters of two adjacent active speed regulating gears decrease sequentially along the cone surface direction towards the output moving cone disk. The first speed regulating component has gear segments corresponding one-to-one with the active speed regulating gears, and each gear segment has teeth that mesh with the corresponding active speed regulating gear. The variable speed control structure and CVT of this invention have advantages such as ingenious structural design, which helps to reduce size, reduce heat generation, and lower failure rate.

Description

Technical Field

[0001] This invention relates to the field of continuously variable transmissions (CVTs), and particularly to a speed regulation structure and a CVT. Background Technology

[0002] A continuously variable transmission (CVT) uses a drive belt and variable-diameter primary and driven pulleys to transmit power, allowing for continuous changes in the transmission ratio and achieving optimal matching between the transmission system and engine operating conditions. To achieve continuously variable transmission, three transmission methods can be used: hydraulic transmission, electric transmission, and mechanical transmission. Among these, mechanically driven CVTs offer stable speed, low slippage, reliable operation, constant power mechanical characteristics, high transmission efficiency, simple structure, easy maintenance, and relatively low cost, making them widely used.

[0003] Currently, common continuously variable transmissions (CVTs) with mechanical transmissions mainly use conical discs and metal V-belts. The metal V-belt connects the driven pulley and the driving pulley. Both the driven pulley and the driving pulley consist of a pair of oppositely arranged conical discs. The metal V-belt is sandwiched between the pair of conical discs. When the two conical discs are close to each other, they squeeze the metal V-belt outward to expand, thereby adjusting the working diameter of the V-belt on the driven pulley and the driving pulley, and realizing the change of transmission speed ratio.

[0004] During the speed change process, as the working radius of the metal V-belt increases, the torque of the metal V-belt also increases. In order to ensure that the drive pulley can further push the metal V-belt to increase its working radius and change the transmission ratio, a drive mechanism (such as a drive motor) with a larger output torque is required. This will increase the overall size of the drive mechanism, and the larger output torque of the drive mechanism will also increase heat generation and affect the stability of the operation. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is: how to provide a speed regulation structure and continuously variable transmission with ingenious structural design that is conducive to reducing volume, reducing heat generation, and reducing failure rate.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A variable speed control structure includes an output shaft and an output movable cone disk axially movably sleeved on the output shaft. A first speed regulating component, which can rotate relative to the output movable cone disk, is coaxially disposed on the side of the output movable cone disk away from the cone surface. A second speed regulating component, which can rotate relative to the output shaft, is coaxially disposed on the output shaft. Both the first and second speed regulating components are rotating bodies and are engaged with each other through a helical pushing structure. The structure is characterized by further including a speed regulating shaft arranged parallel to the output shaft. The speed regulating shaft has at least two active speed regulating gears, the diameters of two adjacent active speed regulating gears decreasing sequentially along the cone surface direction towards the output movable cone disk. The first speed regulating component has gear segments corresponding one-to-one with the active speed regulating gears, and each gear segment has teeth that mesh with the corresponding active speed regulating gear. Two axially adjacent gear segments are interconnected in the circumferential direction, such that at any given time only one gear segment's teeth mesh with the corresponding active speed regulating gear.

[0008] In use, the second speed regulating component can be connected to the housing of the continuously variable transmission (CVT) to prevent it from rotating. During speed regulation, the driving shaft rotates, and the largest diameter active speed regulating gear meshes with the teeth on the corresponding gear segment. At this time, the working radius of the metal V-belt is small, and the speed regulating mechanism can drive the first speed regulating component to rotate rapidly through the larger diameter active speed regulating gear, achieving rapid speed change. Once the meshing stroke of this gear segment ends, the relatively smaller diameter active speed regulating gear meshes with the teeth on the corresponding gear segment, the rotational speed of the first speed regulating component decreases, the speed regulating torque increases, and the speed regulation becomes smoother. In this way, by changing the speed ratio of the meshing teeth between the speed regulating shaft and the first speed regulating component, in the range where a larger speed regulating torque is required, deceleration and torque increase are achieved, satisfying both the rapid speed change requirements in the early stage of the transmission and the stable speed change requirements in the later stage. This allows for the selection of a smaller speed regulating drive mechanism, reducing size, heat generation, and failure rate.

[0009] Furthermore, the axial travel of the first speed regulating component through the central angle corresponding to the gear segment is the driving stroke of the gear segment, and the width of the active speed regulating gear is equal to the sum of the width of the corresponding gear segment and its driving stroke.

[0010] In this way, when the active speed regulating gear and the corresponding gear segment just mesh, the two are flush on the side away from the cone surface of the output moving cone. As the active speed regulating gear drives the first speed regulating component to rotate, the gear segment moves axially relative to the active speed regulating gear. When the gear segment is about to disengage from the active speed regulating gear, the other side of the two are flush. At this time, the adjacent active speed regulating gear and the corresponding gear segment enter the meshing preparation state. In this way, the transmission of the two adjacent gear segments can be better connected.

[0011] Furthermore, the sum of the central angles of all the gear segments is less than or equal to 360 degrees.

[0012] Furthermore, the spiral pushing structure includes a guide groove and a pushing block. The guide groove and the pushing block are respectively disposed on the opposite side of the first speed regulating component and the second speed regulating component. The guide groove is gradually recessed in the circumferential direction in the first speed regulating component or / and the second speed regulating component. The pushing block is protruding on the second speed regulating component or the first speed regulating component opposite to the guide groove, and the pushing block can slide into or out of the guide groove in the circumferential direction.

[0013] In this way, the guide groove, which is gradually recessed along the circumference, and the pushing block form a spiral pushing structure between the first speed regulating component and the second speed regulating component. When the first speed regulating component and the second speed regulating component rotate relative to each other, the corresponding pushing block slides into or out of the guide groove along the circumference, pushing the first speed regulating component to move axially relative to the second speed regulating component, thereby driving the output moving cone disk to move axially on the output shaft to achieve speed regulation.

[0014] Furthermore, the guide groove has a semi-circular groove on the second or first speed regulating component directly opposite to it, and the pushing block is a ball that is rotatably disposed in the groove.

[0015] In this way, during the relative rotation of the first and second speed regulating components, the pushing block (ball) can roll in the guide groove, thereby reducing the friction between the pushing block and the guide groove, making speed regulation smoother, and extending service life.

[0016] Furthermore, both the first and second speed regulating components have the guide groove on their opposite sides, and the pushing block is a ball that is rotatably disposed in the guide groove.

[0017] Furthermore, the guide grooves on the first speed regulating component and the guide grooves on the second speed regulating component are gradually recessed in opposite directions in the circumferential direction.

[0018] In this way, during the relative rotation of the first and second speed regulating components, the steel balls roll in or out of the two guide grooves simultaneously. Within the same speed regulation time, the axial pushing stroke is doubled, which can greatly reduce the speed regulation time, shorten the response event, and improve the response speed.

[0019] Furthermore, the first speed regulating component is a speed regulating nut sleeve, the second speed regulating component is a speed regulating screw, and the spiral pushing structure is a spiral transmission fit structure between the speed regulating nut sleeve and the speed regulating screw.

[0020] Furthermore, the output moving cone disk has a bearing seat extending axially on its back side, and the first speed regulating component has a recessed bearing hole on its side facing the output moving cone disk. The first speed regulating component is rotatably mounted on the output moving cone disk via an angular contact ball bearing disposed on the bearing seat and the bearing hole. A bushing is fitted on the output shaft, and the end of the bushing opposite to the output moving cone disk has a radially protruding flange. The second speed regulating component has a recessed bearing hole on its side opposite to the output moving cone disk, and the second speed regulating component is rotatably mounted on the output shaft via an angular contact ball bearing disposed on the bushing and the bearing hole. The output shaft has a coaxially arranged positioning ring groove, and the bushing opposite to the output moving cone disk has a recessed positioning groove. A retaining ring is embedded in the positioning ring groove and the positioning groove. The inner diameter of the retaining ring is the same as the minimum diameter of the positioning ring groove, and the outer diameter is the same as the maximum diameter of the positioning groove. The retaining ring is composed of a retaining ring arc, and the arc length of the retaining ring arc is less than the arc length of the retaining ring semicircle.

[0021] Because the output shaft typically has a protruding portion, the bushing can only be fitted onto the output shaft from its smallest end. To prevent the bushing from detaching axially, a fixing component is usually installed outside the bushing to restrict its outward axial movement. However, this results in a larger axial dimension of the output shaft. The above structure, using a retaining ring arc forming a retaining ring that is embedded in the positioning ring groove and positioning slot, not only prevents the retaining ring arc from falling out of the positioning ring groove through the positioning slot on the bushing, but also allows the axial dimension of the retaining ring to overlap with the axial dimension of the bushing, reducing the axial space of the output shaft.

[0022] A continuously variable transmission (CVT) is characterized by comprising an output shaft, an input shaft, and a drive belt. The output shaft has an output moving cone disc and an output fixed cone disc arranged opposite each other, the output moving cone disc and the output fixed cone disc forming a driven pulley. The input shaft has an input moving cone disc and an input fixed cone disc arranged opposite each other, the input moving cone disc and the input fixed cone disc forming a driving pulley. The drive belt is connected to the driven pulley and the driving pulley. It also includes a speed regulation structure as described above.

[0023] In summary, the variable speed control structure and continuously variable transmission of the present invention have the advantages of ingenious structural design, which helps to reduce size, reduce heat generation, and reduce failure rate. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of Example 1.

[0025] Figure 2 This is a three-dimensional structural diagram of the speed regulation structure.

[0026] Figure 3 This is a schematic diagram of the structure of Example 2.

[0027] Figure 4 This is a schematic diagram of the structure of the second speed regulating component and the guide groove in Example 2. Detailed Implementation

[0028] The present invention will be further described in detail below with reference to the embodiments.

[0029] Example 1:

[0030] like Figure 1 and Figure 2 As shown, a continuously variable transmission (CVT) includes an output shaft 1, an input shaft 4, and a drive belt 5. The output shaft 1 has an output moving cone 21 and an output fixed cone 22 arranged opposite each other, which together form a driven pulley. The input shaft 4 has an input moving cone 41 and an input fixed cone 42 arranged opposite each other, which together form a driving pulley. The drive belt 5 connects the driven pulley and the driving pulley.

[0031] The output moving cone disk 21 is axially movable and sleeved on the output shaft 1. A first speed regulating component 11, which can rotate relative to the output cone disk 21, is coaxially disposed on the side of the output moving cone disk 21 away from the cone surface. A second speed regulating component 12, which can rotate relative to the output shaft 1, is coaxially disposed on the output shaft 1. Both the first speed regulating component 11 and the second speed regulating component 12 are rotating bodies, and they are engaged with each other through a helical pushing structure. In this embodiment, the first speed regulating component 11 is a speed regulating nut sleeve, the second speed regulating component 12 is a speed regulating screw, and the helical pushing structure is a helical transmission engagement structure between the speed regulating nut sleeve and the speed regulating screw.

[0032] It also includes a speed regulating shaft 3 arranged parallel to the output shaft 1, the speed regulating shaft 3 having at least two active speed regulating gears 31, the diameter of two adjacent active speed regulating gears 31 decreasing sequentially along the conical surface direction toward the output moving cone disk 21; the first speed regulating component 11 has gear segments 19 arranged one-to-one with the active speed regulating gears 31, the gear segments 19 having teeth that mesh with the corresponding active speed regulating gears 31; two axially adjacent gear segments 19 are connected to each other in the circumferential direction, so that at any given time only the teeth of one gear segment 19 mesh with the corresponding active speed regulating gear 31.

[0033] like Figure 2 As shown in this embodiment, three active speed regulating gears 31 are arranged sequentially along the axial direction, and correspondingly, three gear segments 19 are also arranged, and the sum of the central angles of the three gear segments 19 is equal to 360 degrees.

[0034] In use, the second speed regulating component can be connected to the housing of the continuously variable transmission (CVT) to prevent it from rotating. During speed regulation, the driving shaft rotates, and the largest diameter active speed regulating gear meshes with the teeth on the corresponding gear segment. At this time, the working radius of the metal V-belt is small, and the speed regulating mechanism can drive the first speed regulating component to rotate rapidly through the larger diameter active speed regulating gear, achieving rapid speed change. Once the meshing stroke of this gear segment ends, the relatively smaller diameter active speed regulating gear meshes with the teeth on the corresponding gear segment, the rotational speed of the first speed regulating component decreases, the speed regulating torque increases, and the speed regulation becomes smoother. In this way, by changing the speed ratio of the meshing teeth between the speed regulating shaft and the first speed regulating component, in the range where a larger speed regulating torque is required, deceleration and torque increase are achieved, satisfying both the rapid speed change requirements in the early stage of the transmission and the stable speed change requirements in the later stage. This allows for the selection of a smaller speed regulating drive mechanism, reducing size, heat generation, and failure rate.

[0035] In practice, the axial travel of the first speed regulating component 11 through the central angle corresponding to the gear segment 19 is the driving stroke of the gear segment 19, and the width of the active speed regulating gear 31 is equal to the sum of the width of the corresponding gear segment 19 and its driving stroke.

[0036] In this way, when the active speed regulating gear and the corresponding gear segment just mesh, the two are flush on the side away from the cone surface of the output moving cone disk 21. As the active speed regulating gear drives the first speed regulating component to rotate, the gear segment moves axially relative to the active speed regulating gear. When the gear segment is about to disengage from the active speed regulating gear, the other side of the two are flush. At this time, the adjacent active speed regulating gear and the corresponding gear segment enter the meshing preparation state. In this way, the transmission of the two adjacent gear segments can be better connected.

[0037] The output moving cone disk 21 has a bearing seat extending axially on its back side. The first speed regulating member 11 has a recessed bearing hole on its side facing the output moving cone disk 21. The first speed regulating member 11 is rotatably mounted on the output moving cone disk 21 by means of an angular contact ball bearing provided on the bearing seat and the bearing hole. A bushing 15 is sleeved on the output shaft 1. The end of the bushing 15 opposite to the output moving cone disk 21 has a radially protruding flange. The second speed regulating member 12 has a recessed bearing hole on its side opposite to the output moving cone disk 21. The second speed regulating member 12 is rotatably mounted on the output shaft 1 by means of an angular contact ball bearing provided on the bushing 15 and the bearing hole.

[0038] In this embodiment, the output shaft 1 has a coaxially arranged positioning ring groove, and the bushing 15 has a recessed positioning groove on the side opposite to the output moving cone disk 21. A retaining ring 16 is embedded in the positioning ring groove and the positioning groove. The inner diameter of the retaining ring 16 is consistent with the minimum diameter of the positioning ring groove, and the outer diameter is consistent with the maximum diameter of the positioning groove. The retaining ring 16 is composed of a retaining ring arc in the shape of a circular arc, and the arc length of the retaining ring arc is less than the arc length of the retaining ring semicircle.

[0039] Because the output shaft typically has a protruding portion, the bushing can only be fitted onto the output shaft from its smallest end. To prevent the bushing from detaching axially, a fixing component is usually installed outside the bushing to restrict its outward axial movement. However, this results in a larger axial dimension of the output shaft. The above structure, using a retaining ring arc forming a retaining ring that is embedded in the positioning ring groove and positioning slot, not only prevents the retaining ring arc from falling out of the positioning ring groove through the positioning slot on the bushing, but also allows the axial dimension of the retaining ring to overlap with the axial dimension of the bushing, reducing the axial space of the output shaft.

[0040] Example 2

[0041] The main difference from Example 1 is that, as Figure 3 and Figure 4 As shown, the spiral pushing structure includes a guide groove 13 and a pushing block 14. The guide groove 13 and the pushing block 14 are respectively disposed on the opposite side of the first speed regulating member 11 and the second speed regulating member 12. The guide groove 13 is gradually recessed in the first speed regulating member 11 or / and the second speed regulating member 12 in the circumferential direction. The pushing block 14 is protruding on the second speed regulating member 12 or the first speed regulating member 11 opposite to the guide groove 13, and the pushing block 14 can slide into or out of the guide groove 13 in the circumferential direction.

[0042] In this way, the guide groove, which is gradually recessed along the circumference, and the pushing block form a spiral pushing structure between the first speed regulating component and the second speed regulating component. When the first speed regulating component and the second speed regulating component rotate relative to each other, the corresponding pushing block slides into or out of the guide groove along the circumference, pushing the first speed regulating component to move axially relative to the second speed regulating component, thereby driving the output moving cone disk to move axially on the output shaft to achieve speed regulation.

[0043] In practice, the guide groove 13 has a semi-circular groove on the second speed regulating member 12 or the first speed regulating member 11 directly opposite it, and the push block 14 is a ball that can be rolled in the groove.

[0044] In this way, during the relative rotation of the first and second speed regulating components, the pushing block (ball) can roll in the guide groove, thereby reducing the friction between the pushing block and the guide groove, making speed regulation smoother, and extending service life.

[0045] In practice, the first speed regulating component 11 and the second speed regulating component 12 each have the guide groove 13 on their opposite sides, and the pushing block 14 is a ball that is rotatably disposed in the guide groove 13.

[0046] In practice, the guide groove 13 on the first speed regulating component 11 and the guide groove 13 on the second speed regulating component 12 are gradually recessed in opposite directions in the circumferential direction.

[0047] In this way, during the relative rotation of the first and second speed regulating components, the steel balls roll in or out of the two guide grooves simultaneously. Within the same speed regulation time, the axial pushing stroke is doubled, which can greatly reduce the speed regulation time, shorten the response event, and improve the response speed.

[0048] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A variable speed control structure, comprising an output shaft (1) and an output moving cone disk (21) axially movably sleeved on the output shaft (1), wherein a first speed regulating element (11) rotatable relative to the output moving cone disk (21) is coaxially disposed on the side opposite to the cone surface, and a second speed regulating element (12) rotatable relative to the output shaft (1) is coaxially disposed on the output shaft (1), wherein both the first speed regulating element (11) and the second speed regulating element (12) are rotating bodies, and the two are engaged by a helical pushing structure; characterized in that, It also includes a speed regulating shaft (3) arranged parallel to the output shaft (1), the speed regulating shaft (3) having at least two active speed regulating gears (31), the diameter of two adjacent active speed regulating gears (31) decreasing sequentially along the conical surface direction toward the output moving cone disk (21); the first speed regulating member (11) has gear segments (19) arranged one-to-one with the active speed regulating gears (31), the gear segments (19) having teeth that mesh with the corresponding active speed regulating gears (31); two axially adjacent gear segments (19) are connected to each other in the circumferential direction, so that at any given time only the teeth of one gear segment (19) mesh with the corresponding active speed regulating gear (31); the axial travel of the first speed regulating member (11) through the central angle subtended by the gear segment (19) is the driving stroke of the gear segment (19), and the width of the active speed regulating gear (31) is equal to the sum of the width of the corresponding gear segment (19) and its driving stroke.

2. The variable speed control structure as described in claim 1, characterized in that, The sum of the central angles of all the gear segments (19) is less than or equal to 360 degrees.

3. The variable speed control structure as described in claim 1, characterized in that, The spiral pushing structure includes a guide groove (13) and a pushing block (14). The guide groove (13) and the pushing block (14) are respectively disposed on the side opposite to the first speed regulating member (11) and the second speed regulating member (12). The guide groove (13) is gradually recessed in the circumferential direction on the first speed regulating member (11) or / and the second speed regulating member (12). The pushing block (14) is protruding on the second speed regulating member (12) or the first speed regulating member (11) opposite to the guide groove (13). The pushing block (14) can slide into or out of the guide groove (13) in the circumferential direction.

4. The variable speed control structure as described in claim 3, characterized in that, The guide groove (13) has a semi-circular groove on the second speed regulating member (12) or the first speed regulating member (11) directly opposite it, and the push block (14) is a ball that can be rolled in the groove.

5. The variable speed control structure as described in claim 3, characterized in that, The first speed regulating component (11) and the second speed regulating component (12) each have the guide groove (13) on opposite sides, and the push block (14) is a ball that is rotatably disposed in the guide groove (13).

6. The variable speed control structure as described in claim 5, characterized in that, The guide groove (13) on the first speed regulating component (11) and the guide groove (13) on the second speed regulating component (12) are gradually recessed in opposite directions in the circumferential direction.

7. The variable speed control structure as described in claim 1, characterized in that, The first speed regulating component (11) is a speed regulating nut sleeve, the second speed regulating component (12) is a speed regulating screw, and the spiral pushing structure is a spiral transmission cooperation structure between the speed regulating nut sleeve and the speed regulating screw.

8. The variable speed control structure as described in claim 1, characterized in that, The output moving cone disk (21) has a bearing seat extending axially on its back side. The first speed regulating member (11) has a recessed bearing hole on the side facing the output moving cone disk (21). The first speed regulating member (11) is rotatably mounted on the output moving cone disk (21) by means of an angular contact ball bearing provided on the bearing seat and the bearing hole. A bushing (15) is fitted on the output shaft (1). The end of the bushing (15) facing away from the output moving cone disk (21) has a radially protruding flange. The second speed regulating member (12) has a recessed bearing on the side facing away from the output moving cone disk (21). The second speed regulating component (12) is rotatably mounted on the output shaft (1) via an angular contact ball bearing disposed on the bushing (15) and the bearing hole; the output shaft (1) has a coaxially arranged positioning ring groove, and the bushing (15) has a recessed positioning groove on the side opposite to the output moving cone (21). A retaining ring (16) is embedded in the positioning ring groove and the positioning groove. The inner diameter of the retaining ring (16) is consistent with the minimum diameter of the positioning ring groove, and the outer diameter is consistent with the maximum diameter of the positioning groove. The retaining ring (16) is composed of a retaining ring arc in the shape of a circular arc, and the arc length of the retaining ring arc is less than the arc length of the retaining ring semicircle.

9. A continuously variable transmission, characterized in that, The device includes an output shaft (1), an input shaft (4), and a transmission belt (5). The output shaft (1) has an output moving cone disc (21) and an output fixed cone disc (22) arranged opposite each other, which together form a driven wheel. The input shaft (4) has an input moving cone disc (41) and an input fixed cone disc (42) arranged opposite each other, which together form a driving wheel. The transmission belt (5) is connected to the driven wheel and the driving wheel. The device also includes a speed regulation structure as described in any one of claims 1 to 8.

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