A spinless multi-roller continuously variable transmission unit

Abstract

This invention discloses a spinless multi-roller cone continuously variable transmission (CVT) unit, aiming to provide a CVT unit that avoids spin efficiency loss within its gear ratio range, is easy to manufacture, has a long lifespan, and provides high torque. Its key technical features are: the transmission unit consists of a spindle, input sleeve, output sleeve, input roller, output roller, force-transmitting cone, cone mounting shaft, and speed-regulating sleeve. Power is input through the input sleeve, passing sequentially through the input roller, force-transmitting cone, and output roller, and finally output through the output sleeve. A speed-regulating sleeve is arranged on the spindle, hinged to one end of the cone mounting shaft. During speed adjustment, the orientation of the force-transmitting roller is changed by moving the speed-regulating sleeve, and other traction elements follow and maintain contact. The working surface of the force-transmitting cone is a standard conical surface, while the input and output rollers are convex curved surfaces. This invention can be used to replace the transmission unit in a traction-type CVT, enabling the transmission to achieve spinless, efficient transmission with excellent overall performance.

Description

Technical Field

[0001] This invention relates to a transmission unit in a transmission system, specifically a traction-type continuously variable transmission (CVT). Background Technology

[0002] Currently, environmental pollution and energy consumption are two major problems facing the world. Continuously variable transmissions (CVTs) are an ideal transmission solution, providing a series of continuous gear ratios that keep the internal combustion engine operating at its most efficient point, thus improving overall transmission efficiency and reducing emissions. Existing mechanical CVTs can be mainly divided into friction-type CVTs and traction-type CVTs. For large-displacement internal combustion engine vehicles, traction-type CVTs offer higher transmission efficiency (typically 75%-90%) and transmit greater torque compared to friction-type CVTs. Therefore, traction-type CVTs have received widespread attention and research in this field.

[0003] A traction-type continuously variable transmission (CVT) mainly refers to a CVT that uses the rolling motion of the driving element to drive the rolling motion of the driven element to transmit power. The traction-type CVT unit is the collection of the main transmission elements in a traction-type CVT. The transmission elements are rigid, but the contact points are often not direct contact between rigid bodies. Instead, an oil film is formed in between. Under pressure, the viscosity of the oil film increases, reaching a state similar to a solid, thereby transmitting a larger shear force.

[0004] The efficiency losses of a traction-type continuously variable transmission (CVT) mainly include: spin loss, slip loss, sideslip loss, bearing loss, and oil churning loss. Among these losses, the most important is the "spin" loss. "Spin" refers to the situation where the speeds of the driving and driven components are inconsistent at different points in the contact area during traction transmission. This situation leads to adverse consequences such as reduced efficiency and oil film heating, ultimately affecting the traction transmission performance.

[0005] Spin loss is also the efficiency loss that researchers in this field are most concerned about. On the one hand, compared with other types of losses, spin loss accounts for a relatively large proportion of the total efficiency loss, generally 40%-60%, and the proportion of spin loss is even larger when the transmission load is small; on the other hand, other types of losses are often generated along with the transmission process, that is, they cannot be avoided, while spin loss can be eliminated through some methods.

[0006] Spin loss only disappears when the rotation axes of the driving component, the driven component, and the plane of the traction oil film are parallel or intersect at a single point; spin loss exists in all other traction transmission scenarios. It is easy to see that continuously variable transmissions (CVTs) struggle to simultaneously achieve continuous speed regulation and the required relative geometric position without spin. Therefore, all existing conventional traction CVT products exhibit spin loss.

[0007] To eliminate spin loss, a spinless transmission unit was proposed (patent application publication number CN104776180A). In this transmission unit, the generatrices of both the driving and driven cones are specific logarithmic curves. During speed regulation, both the driving and driven cones will move or oscillate. Although this technical solution can eliminate spin, it also has two shortcomings: first, the generatrices of the driving and driven cones use complex logarithmic curves, which makes manufacturing difficult; second, speed regulation control is relatively complicated. Subsequently, in order to overcome the above two shortcomings, a traction-type continuously variable transmission (CVT) was proposed (patent application publication number CN105276110A). This technical solution transmits power to symmetrically distributed conical gears on both sides through an active roller, and then transmits the output directly through bevel gears. The parts in these transmission elements are mostly common spherical or conical surfaces, which are easy to manufacture, and speed adjustment is also relatively convenient during transmission. However, this technical solution introduces bevel gear transmission, which affects efficiency. Moreover, the lack of structural symmetry makes it difficult to use two sets of transmission units in parallel. In addition, only two conical discs can be distributed around the same roller, which results in a small amount of torque being transmitted.

[0008] Another factor affecting the performance of traction-type continuously variable transmissions (CVTs) is fatigue strength. To transmit torque, traction-type CVTs require tightly pressed contact between transmission components, resulting in significant contact stress at the contact points and impacting the overall system lifespan. In existing traction-type CVTs, the position of this contact point relative to specific transmission components can change during speed adjustment, but not necessarily relative to all components. For example, a ring-shaped CVT disclosed in Chinese Patent Publication No. CN101479503B transmits power through friction between the input and output discs and the power roller. While the position of the contact point relative to the input and output discs changes after speed adjustment, its position relative to the power roller remains essentially unchanged. This makes specific areas of the power roller more susceptible to fatigue damage due to repeated compression. Similarly, a conical friction ring CVT disclosed in Chinese Patent Publication No. CN102635671B transmits power through friction between the input and output cones and the friction ring. While the position of the contact point relative to the input and output cones changes after speed adjustment, its position relative to the friction ring remains essentially unchanged, making the friction ring more prone to fatigue damage.

[0009] If the contact points of a traction continuously variable transmission (CVT) can change their positions relative to all transmission components after speed adjustment, this will naturally increase the service life of the transmission.

[0010] In general, the shortcomings of existing technologies are: all existing conventional traction continuously variable transmissions (CVTs) have spin losses; and none of the recently proposed spin-eliminating technologies offer good overall performance. Good overall performance includes: ease of manufacturing, simple speed adjustment, high transmission efficiency, ease of parallel transmission of large torques, and long service life. Summary of the Invention

[0011] The purpose of this invention is to overcome the shortcomings of the prior art and provide a continuously variable transmission unit that can avoid spin efficiency loss within a certain speed ratio range. At the same time, this transmission unit has comprehensive excellent performance, including easy manufacturing, simple speed adjustment, high transmission efficiency, and easy parallel transmission of large torque.

[0012] To solve the above-mentioned technical problems, the present invention will adopt the following technical solution: a non-spinning multi-roller continuously variable transmission unit, including a spindle (1), an input bushing (2a), an output bushing (2b), an input roller (3a), an output roller (3b), a force transmission roller (4), a roller mounting shaft (5), and a speed regulating bushing (6).

[0013] The input sleeve (2a) is mounted on the spindle (1) and can slide and rotate relative to the spindle (1). The input roller (3a) is fixedly connected to the input sleeve (2a). The output sleeve (2b) is mounted on the spindle (1) and can slide and rotate relative to the spindle (1). The output sleeve (2b) is fixedly connected to the output roller (3b). The force transmission cone (4) is mounted on the cone mounting shaft (5) between the input roller (3a) and the output roller (3b). It can rotate relative to the cone mounting shaft (5) around the cone rotation axis (8), but cannot slide relative to the cone mounting shaft (5). One side of the force transmission cone (4) is pressed against the input roller (3a) at the input point (15a), and the other side is pressed against the output roller (3b) at the output point (15b).

[0014] Speed ​​regulating bushing (6) is slidably mounted on spindle (1); one end of tapered roller mounting shaft (5) is hinged to speed regulating bushing (6), and the other end of tapered roller mounting shaft (5) is mounted with roller (13). The roller (13) is mounted in a track (14) perpendicular to spindle (1), and the roller can slide along the track (14).

[0015] In the above scheme, the working surface (10) of the force-transmitting roller (4) is a cone surface, and the cone apex (12) of the cone surface coincides with the axis of the spindle (1).

[0016] In the above scheme, the input roller working surface (9a) on the input roller (3a) is a convex curved surface, specifically a sphere, an ellipsoid, a parabola, etc.

[0017] In the above scheme, the output roller working surface (9b) on the output roller (3b) is a convex curved surface, specifically a sphere, an ellipsoid, a parabola, etc.

[0018] In the above scheme, the number of the force-transmitting rollers (4) is 2, 3, 4 or more, and they are evenly distributed around the axis of the spindle (1) between the input roller (3a) and the output roller (3b).

[0019] The working principle of the non-spinning multi-roller cone continuously variable transmission unit described in this invention is as follows:

[0020] During transmission, power is transmitted through the input shaft sleeve (2a), which rotates together with the input roller (3a). The input roller (3a) pulls the force-transmitting cone (4) to rotate, and the power is transmitted from the input roller (3a) to the force-transmitting cone (4). The force-transmitting cone (4) pulls the output roller (3b) to rotate. The output roller (3b) is connected to the output shaft sleeve (2b) and transmits the power to the output shaft sleeve (2b) for final output. During speed adjustment, the speed adjustment shaft sleeve (6) is driven to move along the spindle (1), causing the cone mounting shaft (5) to swing. The rollers of the cone mounting shaft (5) drive the rollers (13) to move along the track (14), thereby changing the position and attitude of the force-transmitting cone (4). The input roller (3a) and the output roller (3b) slide to the appropriate position on the spindle (1) respectively, keeping the input roller (3a) and the output roller (3b) in close contact with the force-transmitting cone (4). When the position and orientation of the force transmission cone (4) change, the contact radius between the force transmission cone (4) and the input roller (3a) and the output roller (3b) changes. The transmission ratio of the gearbox is the ratio of the contact radii. Thus, the transmission ratio changes, and stepless speed change is achieved.

[0021] The adoption of the above technical solution can produce the following beneficial and positive effects:

[0022] a) High transmission efficiency. The entire system has no spin efficiency loss in any working state, resulting in high transmission efficiency. Moreover, the transmission route of the entire gearbox is relatively compact and there are no unnecessary bevel gear pairs, which further ensures high-efficiency transmission.

[0023] b) Easy to manufacture. The working surface of the power transmission roller (10) is a standard cone surface, and the working surface of the input roller (9a) is a convex curved surface. This curved surface can be a common curved surface such as a sphere or an ellipsoid, which makes the processing of the transmission element easier.

[0024] c) Speed ​​adjustment is simple. The speed adjustment movement of the transmission is only the position of the speed adjustment sleeve (6) on the spindle (1). Other components are followed, so speed adjustment is relatively easy to control.

[0025] d) It is easy to transmit large torque. Multiple force transmission cones (4) can be arranged between the input roller (3a) and the output roller (3b). In this way, several force transmission cones (4) can transmit torque, thereby enabling the entire continuously variable transmission to transmit a larger torque.

[0026] e) Long service life. After speed adjustment, the position of the input point (15a) relative to the input roller (3a) and the force transmission cone (4) changes, and the position of the output point (15b) relative to the output roller (3b) and the force transmission cone (4) also changes. This makes it less likely for the specific contact position of the transmission element to be fatigued and improves the service life of the system. Attached Figure Description

[0027] Figure 1 is a simplified structural diagram of a non-spinning multi-roller continuously variable transmission unit with a transmission ratio of 1.

[0028] Figure 2 is a simplified structural diagram of a non-spinning multi-roller continuously variable transmission unit when the transmission ratio is not 1.

[0029] Figure 3 shows an embodiment of a dual-chamber eight-roller multi-cone continuously variable transmission (CVT).

[0030] Figure 4 is a cross-sectional view of Figure 3 (AA).

[0031] Figure 5. Partial view of the spherical working surface.

[0032] Figure 6. Partial view of the working surface of the ellipsoid.

[0033] Figure 7. Partial view of the working surface of the parabolic surface. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0035] As attached Figure 1 As shown, the present invention provides a non-spinning multi-roller continuously variable transmission unit, which mainly consists of a spindle (1), an input shaft sleeve (2a), an output shaft sleeve (2b), an input roller (3a), an output roller (3b), a force transmission roller (4), a roller mounting shaft (5), and a speed regulating shaft sleeve (6).

[0036] During transmission, power is transmitted through the input shaft sleeve (2a), which drives the input shaft sleeve (2a) and the input roller (3a) to rotate together. The input roller (3a) pulls the force transmission cone (4) to rotate, and the power is transmitted from the force transmission cone (4) to the output roller (3b) and then to the output shaft sleeve (2b) for final output.

[0037] The input sleeve (2a) is fixedly connected to the input roller (3a). The input sleeve (2a) is mounted on the spindle (1). The input sleeve (2a) and the input roller (3a) can slide along the spindle (1) or rotate relative to the spindle (1) around the rotation axis (7a) of the input roller. The output sleeve (2b) is fixedly connected to the output roller (3b). The output sleeve (2b) is mounted on the spindle (1). The output sleeve (2b) and the output roller (3b) can slide along the spindle (1) or rotate relative to the spindle (1) around the rotation axis (7b) of the output roller. The force-transmitting cone (4) is mounted on the cone mounting shaft (5). The force-transmitting cone (4) can rotate relative to the cone mounting shaft (5) around the rotation axis (8) of the cone. The force-transmitting cone (4) cannot slide relative to the cone mounting shaft (5). The input roller (3a) and the force transmission cone (4) are pressed together at the input point (15a), and the output roller (3b) and the force transmission cone (4) are pressed together at the output point (15b).

[0038] Speed ​​regulating sleeve (6) is mounted on spindle. Speed ​​regulating sleeve (6) can slide along spindle. One end of roller mounting shaft (5) is hinged to speed regulating sleeve (6). The other end of roller mounting shaft (5) is mounted with roller (13). Roller (13) is restricted in track (14). Roller (13) can slide along track (14). Track (14) is perpendicular to spindle (1). The working surface (10) of the force transmission roller on the force transmission roller (4) is a standard cone surface. The cone apex (12) of the cone surface coincides with the axis of spindle (1). The working surface (9a) of input roller is a convex curved surface. The working surface (9b) of output roller is a convex curved surface.

[0039] As attached Figure 2 The image shows the state of this non-spinning multi-roller continuously variable transmission after speed adjustment. During speed adjustment, the speed adjustment sleeve (6) moves along the axis of the spindle (1), and the roller (13) moves along the track (14), thereby changing the position and orientation of the force transmission roller (4). The input roller (3a) and the output roller (3b) slide to the appropriate position on the spindle (1) respectively, keeping the input roller (3a) and the output roller (3b) in close contact with the force transmission roller (4).

[0040] This continuously variable transmission unit has high transmission efficiency. During transmission and speed regulation, since the working surface (10) of the force transmission roller is a standard cone surface, the cone apex (12) of the cone surface always coincides with the axis of the spindle (1); and the force transmission roller (4) rotates around the roller rotation axis (8) when working, and the roller rotation axis (8) coincides with the roller mounting axis (5), which makes the roller rotation axis (8) necessarily pass through the cone apex (12) of the working surface (10) of the force transmission roller; in addition, both the input roller (3a) and the output roller (3b) are mounted on the spindle (1), and the input roller rotation axis (7a) and the output roller rotation axis (7b) must coincide with the spindle (1). In simple terms, for the traction drive at the input point (15a), the rotation axis of the input roller (7a), the rotation axis of the roller cone (8), and the plane (11) where the contact area is located must intersect at the cone apex (12). According to the no-spin condition, such a traction drive has no spin efficiency loss. Similarly, there is no spin loss in the transmission at the output point (15b). In addition, from the perspective of the entire continuously variable transmission unit, no new transmission pair is added, so the high transmission efficiency is further guaranteed. Overall, this spinless continuously variable transmission unit has high transmission efficiency.

[0041] This continuously variable transmission unit is easy to manufacture. Since the main transmission elements in the transmission unit have relatively regular shapes and are common curved surfaces, such as the input roller working surface (9a) which is a curved surface that convexes outward relative to the material direction of the input roller (3a), the curved surface can be a sphere or an ellipsoid; the force transmission cone working surface (10) is a standard cone surface. Since the shapes of these curved surfaces are relatively regular and common, they are easy to process.

[0042] As attached Figure 1 Appendix Figure 2 The diagram shows two structural states with different transmission ratios. The position of the speed regulating sleeve (6) on the spindle (1) is translated to a certain extent, and the corresponding positions of the input roller (3a) and output roller (3b) on the spindle (1) are also translated to a certain extent. However, the translation distances of the input roller (3a) and output roller (3b) are not exactly the same, which is mainly determined by the geometry and positional relationship of the structure. On the other hand, the attached... Figure 2 The simplified structural diagram shown represents the state after speed adjustment. Figure 1 The simplified structural diagram shown represents the state before speed adjustment. After speed adjustment, the position of the input point (15a) relative to the input roller (3a) moves a certain distance away from the spindle (1), and its position relative to the force transmission roller (4) moves a certain distance away from the cone apex. Similarly, the position of the output point (15b) relative to the force transmission roller (4) and the output roller (3b) also changes.

[0043] This continuously variable transmission unit is easy to adjust. The speed adjustment movement of this continuously variable transmission unit is only to move the position of the speed adjustment sleeve (6) on the spindle (1). Other components are all follow-up: the input roller (3a) and the output roller (3b) slide on the spindle to ensure normal contact. The roller (13) is confined in the track (14) and the roller (13) slides along the track (14). Therefore, the speed adjustment is relatively easy to control.

[0044] This continuously variable transmission (CVT) unit has a long service life. Traction-type CVTs have significant contact stress between their transmission components, thus facing fatigue life issues. In typical traction-type CVTs, the relative positions of the contact points to the transmission components do not always change before and after speed adjustment. Therefore, the fatigue life of transmission components whose relative contact points remain constant before and after speed adjustment is severely affected. However, for the spinless multi-roller CVT disclosed in this invention, the positions of the input point (15a) and output point (15b) relative to the transmission components change before and after speed adjustment, which greatly improves the fatigue life of this CVT.

[0045] As attached Figure 3 The diagram shows a simplified structural representation of a multi-roller continuously variable transmission (CVT) capable of transmitting high torque. This embodiment is actually composed of two non-spinning multi-roller CVTs connected in parallel. The input roller (3a) and input bushing (2a) are mounted on a spindle (1) and cannot rotate relative to the spindle (1). The auxiliary input roller (3c) and auxiliary input bushing (2c) are also mounted on the spindle (1) and cannot rotate relative to the spindle (1). During transmission, power is input through the input bushing (2a), and half of the power is transmitted to the input roller (3a), while the other half is transmitted to the spindle (1). The spindle drives the auxiliary input roller (3c) and auxiliary input bushing (2c) to rotate together. In fact, this means that the input roller (3a), input sleeve (2a), spindle (1), auxiliary input roller (3c) and auxiliary input sleeve (2c) rotate as a whole; the input roller (3a) and auxiliary input roller (3c) simultaneously pull multiple force transmission cones (4) arranged around it to rotate together, and the multiple force transmission cones (4) then pull the output roller (3b) and auxiliary output roller (3d) to rotate. The output roller (3b) and auxiliary output roller (3d) are mounted on the output sleeve (2b). The output roller (3b) and auxiliary output roller (3d) can move along the output sleeve (2b) but cannot rotate around the output sleeve (2b). Finally, the power is driven by the output roller (3b) and auxiliary output roller (3d) to rotate the output sleeve (2b) and finally output.

[0046] As attached Figure 4 As shown, it is an appendix Figure 3A cross-sectional view of section AA. Four force-transmitting cones (4) are evenly arranged around the input roller (3a). Each force-transmitting cone (4) is equipped with a cone mounting shaft (5). One end of the cone mounting shaft (5) is hinged to the speed regulating sleeve (6), and the other end is hinged to the track (14) and can slide along the track (14). Four tracks (14) are evenly arranged around the input roller (3a) and are spatially perpendicular to the spindle (1). Similarly, four force-transmitting cones (4) are also evenly arranged around the auxiliary input sleeve (2c). In this way, the entire continuously variable transmission has eight cone drives, which enables the whole to transmit a large torque.

[0047] This continuously variable transmission (CVT) unit can transmit large torques. On the one hand, multiple force-transmitting cones (4) are distributed in this CVT unit, which can divert larger torques; on the other hand, this CVT unit is easy to arrange in parallel, which can transmit even larger torques. According to relevant mature design experience, this CVT unit can transmit a large torque of 560 N∙m after being improved by parallel connection and the addition of multiple rollers.

[0048] As attached Figure 5 As shown, the input roller working surface (9a) and the output roller working surface (9b) can be a spherical surface. This surface is a convex surface relative to the base, and the generatrix of this surface is a circle.

[0049] As attached Figure 6 As shown, the input roller working surface (9a) and the output roller working surface (9b) can be an ellipsoidal surface. This surface is a convex surface relative to the base, and the generatrix of this surface is an ellipse.

[0050] As attached Figure 7 As shown, the input roller working surface (9a) and the output roller working surface (9b) can be a parabolic surface. This surface is a convex surface relative to the base, and the generatrix of this surface is a parabola.

[0051] In summary, the present invention provides a traction-type continuously variable transmission unit that can achieve continuous speed regulation, has no spin loss during transmission, is highly efficient, and has excellent overall performance in terms of ease of manufacturing, simple speed regulation, and easy parallel transmission of large torque.

Claims

1. A non-spinning multi-roller cone continuously variable transmission unit, comprising a mandrel (1), an input shaft sleeve (2a), an output shaft sleeve (2b), an input roller (3a), an output roller (3b), a force transmission roller cone (4), a roller cone mounting shaft (5), a speed regulating shaft sleeve (6); characterized in that: The input sleeve (2a) is mounted on the spindle (1) and can slide relative to the spindle (1). The input roller (3a) is fixedly connected to the input sleeve (2a). The output sleeve (2b) is mounted on the spindle (1) and can slide relative to the spindle (1). The output sleeve (2b) is fixedly connected to the output roller (3b). The force transmission cone (4) is mounted on the cone mounting shaft (5) between the input roller (3a) and the output roller (3b). It can rotate relative to the cone mounting shaft (5) around the cone rotation axis (8), but cannot slide relative to the cone mounting shaft (5). One side of the force transmission cone (4) is pressed against the input roller (3a) at the input point (15a), and the other side is pressed against the output roller (3b) at the output point (15b). The speed regulating sleeve (6) is slidably mounted on the spindle (1). It can slide along the spindle (1); one end of the roller cone mounting shaft (5) is hinged to the speed regulating shaft sleeve (6), and the other end of the roller cone mounting shaft (5) is equipped with a roller (13). The roller (13) is installed in the track (14) perpendicular to the spindle (1) and can slide along the track (14); the working surface (10) of the force transmission roller cone (4) is a cone surface, and the cone apex (12) of the cone surface coincides with the axis of the spindle (1); the working surface (9a) of the input roller (3a) is a convex curved surface; the working surface (9b) of the output roller (3b) is a convex curved surface; the number of the force transmission roller cones (4) is 2, 3 or 4, and the force transmission roller cones (4) are evenly distributed around the axis of the spindle (1) between the input roller (3a) and the output roller (3b).

2. The non-spinning multi-roller continuously variable transmission unit as described in claim 1, characterized in that: The convex surface of the input roller working surface (9a) on the input roller (3a) is a sphere, an ellipsoid, or a parabola; the convex surface of the output roller working surface (9b) on the output roller (3b) is a sphere, an ellipsoid, or a parabola.

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