Transmission device and electric drive axle system

Abstract

The utility model provides a transmission device and an electric drive axle system. The transmission device comprises: a planetary gear mechanism having three elements: a sun gear, a planet carrier, and a ring gear, one of the three elements being used for coupling with a driving device, the three elements including two output elements; the two-stage transmission mechanism is provided with two different transmission ratios, each transmission ratio comprises a driving element and a driven element, and the driven element is used for being coupled with an output device; and the gear shifting mechanism comprises two sets of gear shifting devices, the first set of gear shifting devices can selectively connect one of the two output elements of the planetary gear mechanism with the input end of the two-stage transmission mechanism, and the second set of gear shifting devices can selectively connect one of the two transmission ratios of the two-stage transmission mechanism, so that the transmission device has at least three transmission ratios. Through the combination of the planetary gear mechanism and the two-stage transmission mechanism, the torque transmission requirement is met, the simple and compact structural design is achieved, and the stability of the transmission device is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of automobile parts, and concretely relates to a transmission device and an electric drive axle system. BACKGROUND

[0002] For the electric drive vehicle type needing three-gear transmission, the design of its transmission device needs to consider not only the demand of output torque but also the requirement of compact structure to be applicable to the electric drive vehicle type.

[0003] The current three-gear transmission device is usually realized by a plurality of parallel shaft gear reduction structures, which has the problem of large size and cannot be applicable to the electric drive vehicle type; if the size is reduced, the problem of reduced transmission ratio will be brought, which cannot support larger output torque.

[0004] It should be noted that the information disclosed in the above background section is only used to strengthen the understanding of the background of the utility model, and therefore can include information that does not constitute prior art known to those of ordinary skill in the art. SUMMARY

[0005] Therefore, the utility model provides a transmission device and an electric drive axle system to solve the problem that the current three-gear transmission device cannot meet the demand of output torque and compact structure at the same time.

[0006] According to one aspect of the utility model, a transmission device is provided for connecting between a driving device and an output device, the transmission device comprising: a planetary gear mechanism having three elements: a sun gear, a planet carrier with planet gears, and a ring gear, one of the three elements being used for coupling with the driving device, the three elements including two output elements; a two-stage transmission mechanism having two different transmission ratios, wherein each transmission ratio includes a driving element and a driven element, the driven element being used for coupling with the output device; a gear shifting mechanism including two groups of gear shifting devices, wherein the first group of gear shifting devices can selectively connect one of the two output elements of the planetary gear mechanism with the input end of the two-stage transmission mechanism, and the second group of gear shifting devices can selectively connect one of the two transmission ratios of the two-stage transmission mechanism, so that the transmission device has at least three transmission ratios.

[0007] In some embodiments, the one element is different from the two output elements. For example, in one scheme, the one element is the sun gear, and the two output elements are the planet carrier and the ring gear.

[0008] In some embodiments, the one element is a first output element among the two output elements. For example, in one scheme, the one element is the sun gear, and the sun gear is also one of the two output elements.

[0009] In some embodiments, each group of shift devices includes one bidirectional engagement member, wherein the first engagement member of the first group of shift devices selectively connects one of the two output elements of the planetary gear mechanism with the input end of the two-stage transmission mechanism, and the second engagement member of the second group of shift devices selectively connects one of the two transmission ratios of the two-stage transmission mechanism.

[0010] In some embodiments, the ring gear of the planetary gear mechanism is fixed, and the two output elements are the planet carrier and the sun gear.

[0011] In some embodiments, the sun gear is used as the first output element to be coupled with the driving device.

[0012] In some embodiments, the two engagement members are connected and synchronously moved by one shift fork, so that the transmission device has three transmission ratios.

[0013] In some embodiments, along the movement axis of the two engagement members, the interfaces of the two driving elements of the two-stage transmission mechanism and the two output elements of the planetary gear mechanism are sequentially arranged.

[0014] In some embodiments, the two groups of shift devices are connected with the planetary gear mechanism and the two-stage transmission mechanism by spline fitting or friction synchronization.

[0015] In some embodiments, the two engagement members are separately manipulated, so that the transmission device has four transmission ratios; or the two engagement members are jointly manipulated, so that the transmission device has three transmission ratios.

[0016] In some embodiments, the two-stage transmission mechanism includes two pairs of gear pairs, wherein two driving gears form the two driving elements and two driven gears form the two driven elements; the two driving gears are movably arranged on a first transmission shaft, and the two driven gears are fixedly arranged on a second transmission shaft.

[0017] In some embodiments, the two-stage transmission mechanism includes two pairs of gear pairs, wherein two driving gears form the two driving elements and two driven gears form the two driven elements; the two driving gears are movably arranged on a first transmission shaft, and the two driven gears are fixedly arranged on a second transmission shaft; the two engagement members are arranged on the first transmission shaft, and the shift mechanism further includes a shift fork, which drives the first transmission shaft to move in the axial direction of the first transmission shaft, so as to drive the two engagement members to move in the axial direction of the first transmission shaft.

[0018] In some embodiments, the transmission device further comprises a terminal transmission mechanism, which couples one of the two driven elements with the output device.

[0019] In some embodiments, the terminal transmission mechanism comprises a first transmission gear fixedly arranged on the third transmission shaft and engaged with one of the two driven gears on the second transmission shaft, and a second transmission gear and a third transmission gear engaged with each other, wherein the second transmission gear is fixedly arranged on the third transmission shaft, and the third transmission gear is used for coupling with the output device.

[0020] In some embodiments, the transmission ratio of the gear pair in which the driven gear engaged with the first transmission gear is less than the other transmission ratio of the two-stage transmission mechanism.

[0021] In some embodiments, the terminal transmission mechanism comprises a fourth transmission gear and a fifth transmission gear engaged with each other, wherein the fourth transmission gear is fixedly arranged on the second transmission shaft, and the fifth transmission gear is used for coupling with the output device; the transmission device further comprises a head transmission mechanism connected between the planetary gear mechanism and the driving device, and having a transmission ratio not equal to 1.

[0022] In some embodiments, the head transmission mechanism comprises a sixth transmission gear and a seventh transmission gear engaged with each other, wherein the sixth transmission gear is used for connecting with the driving device, and the seventh transmission gear is connected with the first output element of the planetary gear mechanism.

[0023] According to another aspect of the present application, an electric drive axle system is provided, comprising a motor, a differential and a transmission device connected between the motor and the differential; wherein the transmission device is the transmission device according to any of the above embodiments, the motor is used as the driving device, and the differential is used as the output device.

[0024] In some embodiments, the differential is formed by a double-row planetary gear structure.

[0025] The present application has at least the following beneficial effects compared with the prior art:

[0026] The transmission device of the utility model, through the cooperation of planetary gear mechanism and gear shifting mechanism, utilize the first group of gear shifting device of gear shifting mechanism to connect one of two output elements of planetary gear mechanism and the input end of two-stage transmission mechanism, through smaller size, realize at least two kinds of transmission ratio, combine two-stage transmission mechanism and gear shifting mechanism, utilize the second group of gear shifting device of gear shifting mechanism to connect one of two transmission ratio of two-stage transmission mechanism, make transmission device have at least three kinds of transmission ratio.

[0027] Thus, the transmission device of the utility model, through the combination of planetary gear mechanism and two-stage transmission mechanism, and cooperate with the design of gear shifting mechanism, meet the torque transmission demand between driving device and output device, support larger output torque, realize simple and compact structure design, improve stability and reduce product size, can be applied to electric drive vehicle.

[0028] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the utility model. BRIEF DESCRIPTION OF DRAWINGS

[0029] The drawings incorporated into the specification and form part of the specification, show the embodiments consistent with the utility model, and together with the specification, explain the principle of the utility model. Obviously, the drawings in the following description are only some embodiments of the utility model, and for ordinary skilled in the art, other drawings can be obtained according to these drawings without creative labor.

[0030] Figure 1 Show the module schematic diagram of transmission device in the embodiment of the utility model;

[0031] Figure 2 Show a structure schematic diagram of transmission device in the embodiment of the utility model;

[0032] Figures 3 to 7 Show Figure 2 The power flow schematic diagram of transmission device in gear shifting process is shown;

[0033] Figure 8 Show another structure schematic diagram of transmission device in the embodiment of the utility model. DETAILED DESCRIPTION

[0034] Example implementations will now be described more fully with reference to the accompanying drawings. Example implementations can be implemented in any number of ways, and example implementations should not be construed as limited to the implementations set forth herein. Rather, these implementations are provided as non-limiting examples, and the example implementations can be used in combination with embodiments or in standalone modes in various applications.

[0035] The accompanying drawings are not necessarily drawn to scale of one another. The same reference numerals in different drawings represent the same or similar elements and the repeated description thereof will be omitted.

[0036] The terms "first", "second", and similar terms do not imply any order, quantity, or importance, but are used to distinguish one element from another, and are used for the purpose of clear and consistent description. Furthermore, in the description of the present application, when it is said that an element is "connected" to another element, it includes not only the case of direct connection, but also the case of indirect connection through other elements.

[0037] It should be noted that the features of the embodiments of the present application and the features in different embodiments can be combined with each other without conflict.

[0038] Figure 1 The module composition of the transmission device in the embodiment of the present application is schematically shown, and with reference to Figure 1 The transmission device provided by the embodiment of the present application is used for connecting between a driving device 10 and an output device 20, and comprises:

[0039] The planetary gear mechanism 30 has three elements: a sun gear 31, a planet carrier 33 with planet gears, and a ring gear 32, one of the three elements is used for coupling with the driving device 10, and the three elements include two output elements;

[0040] The two-stage transmission mechanism 40 has two different transmission ratios, and each transmission ratio includes a driving element 41 and a driven element 42, the driven element 42 is used for coupling with the output device 20;

[0041] The shift mechanism includes two groups of shift devices, wherein the first group of shift devices 51 can selectively connect one of the two output elements of the planetary gear mechanism 30 with the input end of the two-stage transmission mechanism 40, and the second group of shift devices 52 can selectively connect one of the two transmission ratios of the two-stage transmission mechanism 40, so that the transmission device has at least three transmission ratios.

[0042] The planetary gear mechanism 30 includes three basic elements, a sun gear 31, a planet carrier 33 with planet gears, and a ring gear 32, any one of which can serve as an input element for coupling with the drive device 10, and any two of which can serve as output elements for driving downstream. In some embodiments, the one element is different from the two output elements; for example, in one arrangement, the one element is the sun gear 31, and the two output elements are the planet carrier 33 and the ring gear 32. In such an arrangement, the sun gear 31 serves as an input element, and the planet carrier 33 and the ring gear 32 serve as output elements, respectively, wherein one of the two output elements can be selectively fixed temporarily by two one-way shift elements or one bidirectional shift element, and the power is output through the other; further, the entire planetary gear mechanism 30 can be locked as a whole to provide a direct transmission ratio of 1. In some embodiments, the one element is a first output element among the two output elements; for example, in one arrangement, the one element is the sun gear 31, and the sun gear 31 is also one of the two output elements. In such an arrangement, the sun gear 31 serves as an input element and as one of the output elements, and one of the planet carrier 33 and the ring gear 32 serves as the other output element, and the other can be permanently fixed.

[0043] In the planetary gear mechanism 30, any one element is used for coupling with the drive device 10, and the first group of shift devices 51 of the shift mechanism can selectively connect one of the two output elements with the input end of the two-stage transmission mechanism 40, so that the power from the drive device 10 is transmitted at at least two different transmission ratios through a smaller size. When the first group of shift devices 51 connects the element connected with the drive device 10 with the input end of the two-stage transmission mechanism 40, the power from the drive device 10 is directly transmitted to the rear end components through the element, i.e., the transmission ratio of the planetary gear mechanism 30 at this time is 1. When the first group of shift devices 51 connects the other output element with the input end of the two-stage transmission mechanism 40, the power from the drive device 10 is transmitted to the rear end components through the planetary gear mechanism 30 at a certain transmission ratio; the certain transmission ratio can be determined by the structural design of the planetary gear mechanism 30 according to design requirements. The certain transmission ratio is usually a transmission ratio greater than 1, so that the transmission device supports a larger output torque. The rear end components include the two-stage transmission mechanism 40 and the like.

[0044] The two-stage transmission mechanism 40 has two different transmission ratios, at least one of which can be designed to be greater than 1, so that the transmission supports a larger output torque. The two-stage transmission mechanism 40 is usually implemented by gears; in some possible cases, it can also be implemented by belts or other means. Each transmission ratio of the two-stage transmission mechanism 40 (i.e., each stage of the transmission mechanism) includes a driving element 41 and a driven element 42, wherein the driving element 41 cooperates with the second group of shift devices 52, and the driven element 42 is used to be coupled with the output device 20 to transmit power from the driving device 10 to the output device 20. When the second group of shift devices 52 of the shift mechanism connects the first stage transmission mechanism 40a in the two-stage transmission mechanism 40, the power transmitted from the driving device 10 through the planetary gear mechanism 30 is transmitted to the output device 20 through the first stage transmission mechanism 40a; at this time, the transmission ratio of the two-stage transmission mechanism 40 is the transmission ratio of the first stage transmission mechanism 40a. When the second group of shift devices 52 connects the second stage transmission mechanism 40b in the two-stage transmission mechanism 40, the power transmitted from the driving device 10 through the planetary gear mechanism 30 is transmitted to the output device 20 through the second stage transmission mechanism 40b; at this time, the transmission ratio of the two-stage transmission mechanism 40 is the transmission ratio of the second stage transmission mechanism 40b. The specific values of the transmission ratio of the first stage transmission mechanism 40a and the transmission ratio of the second stage transmission mechanism 40b can be set as needed to meet the requirements of a specific output torque.

[0045] On the basis that the planetary gear mechanism 30 supports at least two transmission ratios and the two-stage transmission mechanism 40 supports two transmission ratios, at least three transmission ratios of the transmission device are realized according to the structural configuration of the two groups of shift devices of the shift mechanism. Specifically, during the movement of one group of shift devices to switch two different transmission ratios, if the other group of shift devices can also switch two different transmission ratios, the transmission device can realize four transmission ratios; during the movement of one group of shift devices to switch two different transmission ratios, if the other group of shift devices remains one transmission ratio, the transmission device can realize three transmission ratios.

[0046] In this way, the transmission device of the utility model, through the combination of the planetary gear mechanism 30 and the two-stage transmission mechanism 40, and cooperating with the design of the shift mechanism, not only meets the torque transmission requirement between the driving device 10 and the output device 20, supports a larger output torque, but also realizes a simple and compact structural design, improves stability and reduces product size, and can be applied to electrically driven vehicles. The transmission device of the utility model has high transmission efficiency, and is especially suitable for commercial electrically driven vehicles.

[0047] Figure 2 A structural design of the transmission device in the embodiment of the utility model is shown, which is described with reference to Figure 2 and in combination with Figure 1As shown, in some embodiments, the ring gear 32 of the planetary gear mechanism 30 is fixed, and the two output elements are the sun gear 31 and the planet carrier 33. Among them, the sun gear 31 is used as the first output element for coupling with the driving device 10. In this way, when the first group of shift devices 51 is connected with the planet carrier 33, the planetary gear mechanism 30 forms a speed reduction and torque increasing transmission structure with the fixed ring gear 32, the driving sun gear 31 and the passive planet carrier 33, so as to realize the transmission of the torque from the driving device 10 after amplification.

[0048] In other embodiments, the fixed element in the planetary gear mechanism 30 is not limited to the ring gear 32, and the first output element for coupling with the driving device 10 is not limited to the sun gear 31, but can be set according to the transmission needs. For example, in a possible implementation, the sun gear 31 of the planetary gear mechanism 30 can be fixed, and the ring gear 32 is used for coupling with the driving device 10, but not limited thereto.

[0049] In some embodiments, as shown in Figure 1 and Figure 2 Each group of shift devices includes a bidirectional engagement element. Among them, the first engagement element 510 of the first group of shift devices 51 can selectively connect one of the two output elements of the planetary gear mechanism 30 with the input end of the two-stage transmission mechanism 40, and the second engagement element 520 of the second group of shift devices 52 can selectively connect one of the two transmission ratios of the two-stage transmission mechanism 40. Through the bidirectional engagement element, two different transmission ratios can be switched. The bidirectional engagement element can also be equivalently replaced by two unidirectional engagement elements, such as clutches, brakes, etc.

[0050] In some embodiments, as shown in Figure 1 and Figure 2 The two engagement elements (including the first engagement element 510 and the second engagement element 520) are connected and can be driven by the same shift fork 53 to move synchronously, so that the transmission device has three transmission ratios. Among them, the moving directions of the two engagement elements can be the same or different, and preferably the same to facilitate the structural design and control. In the case that the two engagement elements are driven by the same shift fork 53 to move synchronously, limited by the structural design of the shift mechanism, in the process that one engagement element moves to switch two different transmission ratios, the other engagement element usually moves synchronously and maintains a transmission ratio, so that the transmission device realizes three transmission ratios to meet the power transmission needs of three-gear shifting. That is, in the case that the two engagement elements are jointly operated, the transmission device can realize three transmission ratios.

[0051] Further, as shown in Figure 1 and Figure 2As shown, in an embodiment where the transmission device achieves three transmission ratios, the interfaces for connecting the two driving elements 41 of the two-stage transmission mechanism 40 and the two output elements of the planetary gear mechanism 30 to the couplings are sequentially arranged along the motion axis "Z" of the two couplings. Thus, in a first possible shifting mode, when the first coupling 510 moves to connect any output element of the planetary gear mechanism 30 to the input end of the two-stage transmission mechanism 40, the second coupling 520 moves synchronously and maintains the connection of one transmission ratio in the two-stage transmission mechanism 40 located closer to the planetary gear mechanism 30; when the second coupling 520 moves to connect another transmission ratio in the two-stage transmission mechanism 40, the first coupling 510 moves synchronously and maintains the connection of the output element in the planetary gear mechanism 30 located closer to the two-stage transmission mechanism 40 to the input end of the two-stage transmission mechanism 40, thereby enabling the transmission device to achieve three transmission ratios. Alternatively, in the second possible shifting method, when the second engagement member 520 moves to engage any one of the gear ratios of the two-stage transmission mechanism 40, the first engagement member 510 moves synchronously and maintains connection between the output element of the planetary gear mechanism 30 located near the two-stage transmission mechanism 40 and the input end of the two-stage transmission mechanism 40; when the first engagement member 510 moves to connect the other output element of the planetary gear mechanism 30 to the input end of the two-stage transmission mechanism 40, the second engagement member 520 moves synchronously and maintains connection between one of the gear ratios of the two-stage transmission mechanism 40 located near the planetary gear mechanism 30, so that the transmission device can achieve three gear ratios.

[0052] Figures 3 to 7 Indicate Figure 2 The power flow of the transmission device shown during gear shifting. Figures 3 to 7 The example shown is the second possible shifting method described above. (Combined with...) Figures 2 to 7 As shown, the gear shifting process of the transmission device includes:

[0053] In first gear, combined Figure 2 and Figure 3 As shown, the power from the driving device 10 is sequentially transmitted to the output device 20 via the sun gear 31 and planet carrier 33 of the planetary gear mechanism 30, the driving element 41 and driven element 42 of the first-stage transmission mechanism 40a, and the optional end-transmission mechanism 60. Let the transmission ratio of the planetary gear mechanism 30 be i1, the transmission ratio of the first-stage transmission mechanism 40a be i2, and the transmission ratio of the end-transmission mechanism 60 be i3. Then, the total transmission ratio of the transmission device in the first gear is: i1 × i2 × i3. In the first gear, the total transmission ratio of the transmission device is large, the output speed is small, and the output torque is large. During the power transmission process, it also passes through transmission structures such as couplings and drive shafts that do not cause changes in the transmission ratio.

[0054] During the shifting process, the shifting can be realized by friction synchronization or by driving device 10 actively adjusting the speed and using spline fitting. Specifically, in the former shifting mode, the two groups of shifting devices are respectively provided with friction elements (such as synchronizers, friction clutches, etc.), and the shifting devices realize the connection of planetary gear mechanism 30 and two-stage transmission mechanism 40 and the connection of two-stage transmission mechanism 40 through the friction elements, thereby synchronizing the rotation speed of the components connected with driving device 10 with the rotation speed of the components connected with output device 20. The former shifting mode has the characteristic of fast shifting speed. In the latter shifting mode, the two transmission ratios of two-stage transmission mechanism 40 (such as between the two driving elements 41) and the two output elements of planetary gear mechanism 30 are respectively provided with neutral positions; the two groups of shifting devices are respectively provided with external teeth (such as the two engaging members are respectively provided with external teeth), and the driving elements 41 and the output elements are respectively provided with internal teeth, which are used to form spline fitting structures allowing rotary transmission and axial sliding. In the latter shifting mode, when one engaging member moves to the corresponding neutral position, driving device 10 actively adjusts the rotation speed to drive the connected components to adjust the speed, so that the rotation speed is adjusted to the gear rotation speed of the gear to be shifted, and then the connection mode of the transmission device is adjusted to the gear to be shifted through the movement of the two engaging members. The latter shifting mode has the characteristics of high shifting efficiency and small impact. When specifically designed, the corresponding shifting mode can be selected according to the needs. For example, in commercial vehicle models, the latter shifting mode can be selected.

[0055] In combination Figures 3 to 5 In the latter shifting mode, when it is necessary to shift from the first gear shown in Figure 3 to the second gear shown in Figure 5 : the two engaging members are moved by shifting yoke 53, so that second engaging member 520 moves to the neutral position N1 between the two driving elements 41 of two-stage transmission mechanism 40, at which time the state of the transmission device is as shown in Figure 4 In the state shown in Figure 4 , driving device 10 actively adjusts the speed of the connected components to the gear rotation speed of the second gear; the two engaging members are continuously moved by shifting yoke 53, so that second engaging member 520 connects the driving element 41 of second-stage transmission mechanism 40b to connect second-stage transmission mechanism 40b, at which time the transmission device shifts to the second gear, as shown in Figure 5 .

[0056] In the second gear, in combination with Figure 2 and Figure 5As shown, the power from the driving device 10 is transmitted sequentially to the output device 20 via the sun gear 31 and planet carrier 33 of the planetary gear mechanism 30, the driving element 41 and driven element 42 of the second-stage transmission mechanism 40b, and the optional end-drive mechanism 60. If the transmission ratio of the second-stage transmission mechanism 40b is i4, then the total transmission ratio of the transmission device in the second gear is: i1 × i4 × i3.

[0057] Combination Figures 5 to 7 As shown, in the latter shifting method, when it is necessary to shift from Figure 5 Shift to the second gear as shown Figure 7 The third gear position shown: The shift fork 53 drives the engagement member to move, causing the first engagement member 510 to move to the neutral position N2 between the planet carrier 33 and the sun gear 31 of the planetary gear mechanism 30. At this time, the state of the transmission device is as follows. Figure 6 As shown; in Figure 6 In the indicated state, the drive unit 10 drives the connected components to actively adjust their speed to the third gear; it continues to drive the engagement member through the shift fork 53, causing the first engagement member 510 to connect to the sun gear 31. At this time, the transmission device shifts to the third gear, as shown. Figure 7 As shown.

[0058] In third gear, combined Figure 2 and Figures 2 to 7 As shown, the power from the driving device 10 is transmitted sequentially to the output device 20 via the sun gear 31, the driving element 41 and driven element 42 of the second-stage transmission mechanism 40b, and the optional end-drive mechanism 60. The total transmission ratio of the transmission device in the third gear is 1×i4×i3. In the third gear, the total transmission ratio of the transmission device is small, the output speed is large, and the output torque is small.

[0059] In some embodiments, the two couplings can also be operated separately, for example, driven independently by two shift forks, so that the transmission has four gear ratios, thus meeting the power transmission requirements of four-speed transmission.

[0060] In some embodiments, combined with Figures 2 to 7 As shown, the two-stage transmission mechanism 40 includes two pairs of gears (i.e., the first-stage transmission mechanism 40a and the second-stage transmission mechanism 40b), wherein two driving gears form two driving elements 41 and two driven gears form two driven elements 42; the two driving gears are movably mounted on the first transmission shaft S1, and the two driven gears are fixedly mounted on the second transmission shaft S2. The stepped transmission formed by the gear pairs has the advantages of accurate transmission and high efficiency.

[0061] Further, in some embodiments, two engaging members are respectively arranged on the first transmission shaft S1, and the shift fork 53 is capable of driving the first transmission shaft S1 to move along the axial direction thereof, so as to drive the first engaging member 510 and the second engaging member 520 to move along the axial direction of the first transmission shaft S1 (i.e. along the movement axis "Z"), thus conveniently realizing the gear shifting operation of the transmission device.

[0062] In the above embodiments, the shift fork 53 is connected to the shift shaft 54, and the shift shaft 54 and the first transmission shaft S1 can be respectively limited by the housing, so as to realize the movement along the movement axis "Z" only.

[0063] Continuing to combine Figures 2 to 7 As shown in the drawings, in some embodiments, the transmission device further comprises a terminal transmission mechanism 60, which is used to couple one of the two driven elements 42 with the output device 20. Through the terminal transmission mechanism 60, a certain transmission ratio is provided, so that the two-stage transmission mechanism 40 does not need to be arranged to be too large, and the output torque requirement of the transmission device can be met, and the overall stability of the transmission device can be improved. The terminal transmission mechanism 60 can realize transmission through gears, belts, etc.

[0064] In some possible implementations, the terminal transmission mechanism 60 comprises: a first transmission gear 61 fixedly arranged on the third transmission shaft S3 and engaged with one of the two driven gears on the second transmission shaft S2; and a second transmission gear 62 and a third transmission gear 63 engaged with each other, wherein the second transmission gear 62 is fixedly arranged on the third transmission shaft S3, and the third transmission gear 63 is used to be coupled with the output device 20. Among them, the transmission ratio between the driven gear and the first transmission gear 61, and the transmission ratio between the second transmission gear 62 and the third transmission gear 63 can be set according to the requirement, and is usually greater than 1, so as to meet the output torque requirement of the transmission device.

[0065] Based on the above implementation, considering the torque transmission, the driven gear meshing with the first transmission gear 61 is connected with the terminal transmission mechanism 60; if the size of the driven gear is too large, in order to make the transmission support larger output torque, it will bring the problem that the size of each gear of the terminal transmission mechanism 60 is also increased, and then the size of the whole transmission is too large. Therefore, in the preferred embodiment, the transmission ratio of the gear pair in which the driven gear meshing with the first transmission gear 61 is less than the other transmission ratio of the two-stage transmission mechanism 40, specifically, the transmission ratio of the gear pair in which the driven gear meshing with the first transmission gear 61 can be close to 1, so as to reasonably control the size of the driven gear meshing with the first transmission gear 61, and then reasonably control the size of the terminal transmission mechanism 60 and the whole transmission. Wherein, the case that the transmission ratio is close to 1 includes: equal to 1, slightly less than 1, slightly greater than 1. For example, the transmission ratio of the gear pair in which the driven gear meshing with the first transmission gear 61 can be controlled in the range of 0.9 to 1.2, but not limited thereto.

[0066] In the embodiment of the transmission device shown in Figure 8 In the embodiment of the terminal transmission mechanism 60 shown in the figure, the first transmission shaft S1 has good inertia and shifting performance. However, in the case of the second gear position and the third gear position, the second transmission shaft S2 has higher transmission requirements, which may cause instability problems. Therefore, the design of the terminal transmission mechanism 60 can be adjusted, and the head-end transmission mechanism can be added to share a certain transmission ratio.

[0067] Figure 2 Another structure of the transmission device in the embodiment of the utility model is shown, and compared with Figure 8 The difference design of the transmission device shown in Figure 8 The difference design of the transmission device shown in Figure 8 The difference design of the transmission device shown in

[0068] Figure 2 The transmission ratio of each transmission component of the transmission device shown in Figure 8 The transmission ratio of each transmission component of the transmission device shown in Figure 8In the transmission device shown, the transmission ratio of the planetary gear mechanism 30 is i1', the transmission ratio of the first-stage transmission mechanism 40a is i2', the transmission ratio of the terminal transmission mechanism 60' is i3', the transmission ratio of the second-stage transmission mechanism 40b is i4', and the transmission ratio of the head-end transmission mechanism 70 is i5 (i5 is not equal to 1). Then, in the first gear position, the total transmission ratio of the transmission device is i5×i1'×i2'×i3'; in the second gear position, the total transmission ratio of the transmission device is i5×i1'×i4'×i3'; and in the third gear position, the total transmission ratio of the transmission device is i5×1×i4'×i3'. Figure 8 In the transmission device shown: in the first gear position, the total transmission ratio of the transmission device is i5×i1'×i2'×i3'; in the second gear position, the total transmission ratio of the transmission device is i5×i1'×i4'×i3'; and in the third gear position, the total transmission ratio of the transmission device is i5×1×i4'×i3'. Wherein, i1', i2', i3', i4' and i5 can be greater than 1 respectively, and the specific values can be set according to requirements.

[0069] Further, referring to Figure 3 As shown, the head-end transmission mechanism 70 includes the sixth transmission gear 71 and the seventh transmission gear 72 which are engaged, wherein the sixth transmission gear 71 is used to be connected with the driving device 10, and the seventh transmission gear 72 is connected with the first output element of the planetary gear mechanism 30. In other embodiments, the head-end transmission mechanism 70 can also be realized by other transmission modes.

[0070] The utility model embodiment further provides an electric drive axle system, including motor, differential and transmission device connected between motor and differential, the structure and principle of transmission device can refer to the description of any embodiment above, motor is used as driving device 10, and differential is used as output device 20. In some implementation ways, the differential can be connected to the wheel end through the output shaft.

[0071] The electric drive axle system of the utility model, through the combination of planetary gear mechanism 30 and two-stage transmission mechanism 40 of transmission device, and cooperate with the design of gear shifting mechanism, can realize at least three transmission ratios, to realize three gears. Wherein, referring to Figure 8 As shown, in the first gear position, the power transmission path (mainly listing the transmission components changing transmission ratio) of the electric drive axle system is: motor (driving device 10) → planetary gear mechanism 30 (transmission ratio i1) → first-stage transmission mechanism 40a (transmission ratio i2) → corresponding driven gear and first transmission gear 61 (transmission ratio i6) → second transmission gear 62 and third transmission gear 63 which are engaged (transmission ratio i7 is set, wherein i6×i7=i3) → differential (output device 20). In the first gear position, the total transmission ratio of the electric drive axle system is: i1×i2×i6×i7. Or, referring to Figure 5As shown, under the first gear, the power transmission path (mainly listing the transmission components changing the transmission ratio) of the electric drive axle system is: motor → first end transmission mechanism 70 (transmission ratio i5) → planetary gear mechanism 30 (transmission ratio i1') → first stage transmission mechanism 40a (transmission ratio i2') → end transmission mechanism 60' (transmission ratio i3') → differential; under the first gear, the total transmission ratio of the electric drive axle system is: i5x i1'x i2'x i3'. Under the first gear, the total transmission ratio of the electric drive axle system can reach 50-60, and the maximum output torque can reach about 35000 Nm.

[0072] Referring to Figure 8 As shown, under the second gear, the power transmission path (mainly listing the transmission components changing the transmission ratio) of the electric drive axle system is: motor → planetary gear mechanism 30 → second stage transmission mechanism 40b (transmission ratio i4) → corresponding driven gear and first transmission gear 61 → meshed second transmission gear 62 and third transmission gear 63 → differential; under the second gear, the total transmission ratio of the electric drive axle system is: i1x i4x i6x i7. Alternatively, referring to Figure 7 As shown, under the second gear, the power transmission path (mainly listing the transmission components changing the transmission ratio) of the electric drive axle system is: motor → first end transmission mechanism 70 → planetary gear mechanism 30 → second stage transmission mechanism 40b (transmission ratio i4') → end transmission mechanism 60' → differential; under the second gear, the total transmission ratio of the electric drive axle system is: i5x i1'x i4'x i3'.

[0073] Referring to Figure 8 As shown, under the third gear, the power transmission path (mainly listing the transmission components changing the transmission ratio) of the electric drive axle system is: motor → sun gear 31 (transmission ratio 1) → second stage transmission mechanism 40b → corresponding driven gear and first transmission gear 61 → meshed second transmission gear 62 and third transmission gear 63 → differential; under the third gear, the total transmission ratio of the electric drive axle system is: 1x i4x i6x i7. Alternatively, referring to ​ As shown, under the third gear, the power transmission path (mainly listing the transmission components changing the transmission ratio) of the electric drive axle system is: motor → first end transmission mechanism 70 → sun gear 31 → second stage transmission mechanism 40b → end transmission mechanism 60' → differential; under the third gear, the total transmission ratio of the electric drive axle system is: i5x 1x i4'x i3'.

[0074] The electric drive axle system of the utility model can meet the torque transmission requirement between the motor and the differential, support larger output torque, realize simple and compact structure design, improve operation stability, reduce product size, and can be applied to electric drive vehicles.

[0075] In some embodiments, the differential can be formed by a double planetary gear structure. Specifically, the end transmission mechanism 60' and the differential can be omitted and replaced by a double planetary gear structure. The double planetary gear structure, such as a coaxial planetary reducer integrated with a differential, is an existing product that simultaneously implements the functions of speed reduction (i.e., provides a certain transmission ratio, instead of the end transmission mechanism 60') and differential (instead of the differential) through two differential planetary rows, and the specific structure and principle thereof will not be described.

[0076] The above is a further detailed description of the present application in combination with specific preferred embodiments, and the specific implementation of the present application should not be limited to these descriptions. For ordinary skilled persons in the technical field to which the present application belongs, without departing from the concept of the present application, a number of simple deductions or substitutions can be made, which should be considered as falling within the protection scope of the present application.

Claims

1. A transmission device for connecting between a driving means and an output means, characterized in that, The transmission comprises: a planetary gear mechanism having three elements: a sun gear, a planet carrier with planet gears, a ring gear, one of the three elements being used for coupling with the driving device, the three elements including two output elements; a two-stage transmission mechanism having two different transmission ratios, each of the transmission ratios including a driving element and a driven element, the driven element being used for coupling with the output device; a shift mechanism including two sets of shift devices, wherein the first set of shift devices selectively connects one of the two output elements of the planetary gear mechanism with the input end of the two-stage transmission mechanism, and the second set of shift devices selectively connects one of the two transmission ratios of the two-stage transmission mechanism, so that the transmission has at least three transmission ratios.

2. The transmission of claim 1, wherein The one element is a first output element among the two output elements.

3. A transmission as claimed in claim 1 or 2, characterised in that, Each set of shift devices includes a bidirectional engagement member, wherein the first engagement member of the first set of shift devices selectively connects one of the two output elements of the planetary gear mechanism with the input end of the two-stage transmission mechanism, and the second engagement member of the second set of shift devices selectively connects one of the two transmission ratios of the two-stage transmission mechanism.

4. The transmission of claim 2, wherein, The ring gear of the planetary gear mechanism is fixed, and the two output elements are the planet carrier and the sun gear.

5. The transmission of claim 4, wherein, The sun gear is used as the first output element for coupling with the driving device.

6. The transmission of claim 3, wherein The two engagement members are connected and can be synchronously moved by a shift fork, so that the transmission has three transmission ratios.

7. The transmission of claim 6 wherein, Along the movement axes of the two engagement members, the interfaces of the two driving elements of the two-stage transmission mechanism and the two output elements of the planetary gear mechanism are sequentially arranged.

8. The transmission of claim 1 or 2, wherein The two sets of shift devices are connected to the planetary gear mechanism and the two-stage transmission mechanism in a spline fit manner or a friction synchronization manner.

9. The transmission of claim 3, wherein The two engagement members can be separately manipulated, so that the transmission has four transmission ratios; or the two engagement members can be jointly manipulated, so that the transmission has three transmission ratios.

10. The transmission of claim 1 or 2, wherein The two-stage transmission mechanism includes two pairs of gear pairs, wherein two driving gears form the two driving elements and two driven gears form the two driven elements; The two driving gears are movably arranged on a first transmission shaft, and the two driven gears are fixedly arranged on a second transmission shaft.

11. The transmission of claim 3, wherein The two-stage transmission mechanism includes two pairs of gear pairs, wherein two driving gears form the two driving elements and two driven gears form the two driven elements; The two driving gears are movably arranged on a first transmission shaft, and the two driven gears are fixedly arranged on a second transmission shaft; The two engagement members are arranged on the first transmission shaft, and the shift mechanism further includes a shift fork, which can drive the first transmission shaft to move in the axial direction of the first transmission shaft, so as to drive the two engagement members to move in the axial direction of the first transmission shaft.

12. The transmission of claim 10, wherein, The transmission further comprises a terminal transmission mechanism coupling one of the two driven elements with the output means.

13. The transmission of claim 12, wherein, The terminal transmission mechanism comprises: a first transmission gear fixedly arranged on the third transmission shaft and engaging with one of the two driven gears on the second transmission shaft; a second transmission gear and a third transmission gear engaging with each other, wherein the second transmission gear is fixedly arranged on the third transmission shaft, and the third transmission gear is used for coupling with the output means.

14. The transmission of claim 13, wherein, The transmission ratio of the gear pair in which the driven gear engaging with the first transmission gear is less than the other transmission ratio of the two-stage transmission mechanism.

15. The transmission of claim 12, wherein, The terminal transmission mechanism comprises a fourth transmission gear and a fifth transmission gear engaging with each other, wherein the fourth transmission gear is fixedly arranged on the second transmission shaft, and the fifth transmission gear is used for coupling with the output means. The transmission further comprises a head transmission mechanism connected between the planetary gear mechanism and the driving means, and having a transmission ratio not equal to 1.

16. The transmission of claim 15, wherein, The head transmission mechanism comprises a sixth transmission gear and a seventh transmission gear engaging with each other, wherein the sixth transmission gear is used for connecting with the driving means, and the seventh transmission gear is connected with the first output element of the planetary gear mechanism.

17. An electric drive axle system comprising an electric motor, a differential, and a transmission connected between the electric motor and the differential; characterized in that The transmission is the transmission according to any one of claims 1-16, the electric motor is used as the driving means, and the differential is used as the output means.

18. The electric drive axle system of claim 17, wherein, The differential is formed by a double-row planetary gear structure.

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