Two-speed automatic transmission for electric vehicle

Abstract

The present invention discloses a two-speed automatic transmission for electric vehicles, and specifically relates to the technical field of transmissions for electric vehicles, including an output shaft and a housing, wherein the output shaft is rotatably arranged in the housing, and a high-speed gear and a high-speed gear are fixed on the outside of the output shaft, and a speed change assembly is arranged on one side of the outer wall of the high-speed gear, and the speed change assembly includes: a bridge shaft, which is rotatably arranged in the housing, and a linkage gear and a first driving gear are fixed on the bridge shaft, and the linkage gear is meshed with the high-speed gear. The present invention realizes instantaneous and smooth switching of high and low gears by setting a speed change assembly, and the input shaft rotates forward and reversely to realize smooth and reliable gear shifting under the action of a controller, and overcomes the problem that the sum of the rotational inertia of the input end is too large and synchronization must be achieved, and thoroughly improves the unstable synchronization performance caused by the easy wear of the synchronizer, so that the reliability and stability of the transmission are better, and the cost is greatly reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle gearboxes, and more specifically, to a two-speed automatic gearbox for electric vehicles. Background Art

[0002] In the prior art, most two-speed synchronous shifting gearboxes have to overcome the large sum of rotational inertia at the input end, so that the input end gear and the output end gear can complete the gear speed synchronization at both ends of the synchronizer under the action of the friction torque of the synchronizer group, thereby achieving gear shifting.

[0003] The patent application publication number CN204327884U discloses an automatic transmission for an electric vehicle, whose shift power shaft is connected to a synchronizer through a planetary lifting mechanism and a shift fork arranged on the planetary lifting mechanism. Since the rotation speed of the servo motor is very high, it is effectively reduced in speed through the planetary mechanism and is equipped with a spiral lifting mechanism, thereby effectively reducing the displacement speed of the lifting rod to a practical shifting speed, reducing the power requirement of the servo motor, and using a smaller power servo motor to achieve the shifting power requirement, thereby reducing production costs.

[0004] However, in the above-mentioned operation mode, since the synchronizer group has many parts, as the friction torque of the synchronizer ring in the synchronizer group increases, the synchronization time of the gears at both ends increases, resulting in an aggravated sense of gear shifting. As the use time increases, the synchronizer ring wears more, resulting in unstable or failure gear shifting performance, thereby losing the stability and reliability of the gearbox. Summary of the invention

[0005] The technical solution of the present invention aims at the technical problem that the existing technical solution is too single, and provides a solution that is significantly different from the existing technology. In order to overcome the above-mentioned defects of the prior art, the present invention provides a two-speed automatic transmission for an electric vehicle to solve the problem mentioned in the above background technology that the wear of the synchronizer ring is aggravated, resulting in unstable or failure of the shifting performance, thereby losing the stability and reliability of the transmission.

[0006] To achieve the above object, the present invention provides the following technical solution: a two-speed automatic transmission for an electric vehicle, comprising an output shaft and a housing, wherein the output shaft is rotatably arranged in the housing, and a high-speed gear and a high-speed gear are fixed to the outside of the output shaft, and a speed change assembly is provided on one side of the outer wall of the high-speed gear, and the speed change assembly comprises:

[0007] A bridge shaft is rotatably arranged on the box body, a linkage gear and a first driving gear are fixedly arranged on the bridge shaft, and the linkage gear is meshed with the high gear;

[0008] A shift shaft is rotatably arranged on the housing, a shift gear is fixedly arranged on the shift shaft, and an adjusting gear and a clutch disc sleeve are rotatably sleeved on the shift shaft, a first one-way device is arranged between the adjusting gear and the shift shaft, a second one-way device is sleeved on the outer side of the clutch disc sleeve, a second drive gear is arranged on the outer side of the second one-way device, the adjusting gear is meshed with the first drive gear, and the drive gear is meshed with the high gear gear;

[0009] The elastic pin clutch, the sliding sleeve is arranged on the shift shaft, and is transmission-connected with a shift device, and is located between the adjusting gear and the clutch disc sleeve. The elastic pin clutch can be inserted into the adjusting gear or the clutch disc sleeve when sliding along the shift shaft.

[0010] The differential output shaft is rotatably arranged on the housing and is fixed with a rotating gear, and the rotating gear is meshed with the shift gear.

[0011] Preferably, the side walls of the adjusting gear and the clutch disc sleeve facing the elastic pin clutch are both provided with clutch holes that can be plugged into the elastic pin clutch.

[0012] Preferably, the elastic pin clutch comprises a clutch sleeve, a shift fork, a return spring, a transmission pin and a pressure plate, a first positioning hole is opened on the surface of the shift shaft, a positioning spring is arranged in the first positioning hole, a positioning steel ball is arranged on the top of the positioning spring, the clutch sleeve is sleeved on the shift shaft, and the inner wall of the clutch sleeve is provided with two groups of steel ball grooves arranged along the axial direction, the top of the positioning steel ball is located in one of the steel ball grooves, the shift fork is clamped on the clutch sleeve, the clutch sleeve is provided with a plurality of second positioning holes through both ends, the pressure plate is provided with two and respectively arranged at the two ends of the clutch sleeve, each of the second positioning holes is provided with a transmission pin, the transmission pin is suitable for being inserted into the clutch hole, and the plurality of transmission pins are divided into two groups;

[0013] The left side of the driving pin of one group extends out of the second positioning hole and the left pressure plate, and the right side of the driving pin of one group is provided with a return spring abutting against the right pressure plate;

[0014] The right side of the driving pin of the other group extends out of the second positioning hole and the pressure plate on the right side, and the left side of the driving pin of the other group is provided with a return spring abutting against the pressure plate on the left side.

[0015] Preferably, the shifting device comprises a hydraulic cylinder and an oil pump, wherein the hydraulic cylinder is fixedly mounted on the outside of the housing, and a shifting rod is disposed at the output end of the hydraulic cylinder, wherein the shifting rod is slidably mounted on the housing and fixedly connected to the shifting fork, and the oil pump is connected to the hydraulic cylinder.

[0016] Technical effects and advantages of the present invention:

[0017] 1. By setting up the speed change assembly, the input shaft can rotate forward and reverse to achieve instantaneous and smooth switching between high and low gears. Under the action of the controller, the gear shifting is smooth and reliable, which solves the problem that the sum of the rotational inertia of the input end is too large and synchronization must be achieved. The defect of unstable synchronization performance caused by easy wear of the synchronizer is improved, making the gearbox more reliable and stable, and greatly reducing the cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention provides a schematic diagram of the partial internal structure of a two-speed automatic transmission case of an electric vehicle.

[0019] Figure 2 The present invention is a schematic diagram of the external structure of a two-speed automatic transmission for an electric vehicle.

[0020] Figure 3 The present invention is a schematic diagram of the local structure of the connection between the output shaft and the high gear and the low gear in a two-speed automatic transmission of an electric vehicle.

[0021] Figure 4 The present invention is a schematic diagram of the vertical cross-section structure of a two-speed automatic transmission for an electric vehicle.

[0022] Figure 5 For the present invention Figure 4 Enlarged structural diagram at A in the middle.

[0023] The accompanying drawings are marked as follows: 1. output shaft; 2. axle shaft; 3. shift shaft; 4. differential output shaft; 6. housing; 7. spring-pin clutch; 11. high gear; 12. low gear; 21. linkage gear; 22. drive gear; 31. shift gear; 32. adjustment gear; 33. clutch sleeve; 34. shift fork; 35. return spring; 36. transmission pin; 37. pressure plate; 38. first positioning hole; 39. positioning spring; 41. rotating gear; 51. second positioning hole; 52. shift rod; 53. hydraulic cylinder; 54. oil pump; 55. first one-way device; 56. second one-way device; 57. positioning steel ball; 58. clutch sleeve; 59. drive gear. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] As attached Figure 1-4As shown, a two-speed automatic transmission for an electric vehicle includes an output shaft 1 and a housing 6. The output shaft 1 is rotatably arranged in the housing 6, and a high-speed gear 11 and a low-speed gear 12 are fixed to the outside of the output shaft 1. A speed change assembly is provided on one side of the outer wall of the low-speed gear 12. The speed change assembly includes:

[0026] The bridge shaft 2 is rotatably arranged on the housing 6. A linkage gear 21 and a first driving gear 22 are fixedly arranged on the bridge shaft 2. The linkage gear 21 is meshed with the low gear 12.

[0027] The shift shaft 3 is rotatably arranged on the housing 6, a shift gear 31 is fixedly arranged on the shift shaft 3, and an adjusting gear 32 and a clutch disc sleeve 58 are rotatably sleeved on the shift shaft 3, a first isolator 55 is arranged between the adjusting gear 32 and the shift shaft 3, a second isolator 56 is sleeved on the outer side of the clutch disc sleeve 58, a driving gear 59 is arranged on the outer side of the second isolator 56, the adjusting gear 32 is meshed with the first driving gear 22, and the driving gear 59 is meshed with the high gear 11;

[0028] The spring pin clutch 7 is slidably sleeved on the shift shaft 3 and is transmission-connected to a shift device and is located between the adjusting gear 32 and the clutch sleeve 58 . The spring pin clutch 7 can be inserted into the adjusting gear 32 or the clutch sleeve 58 when sliding along the shift shaft 3 .

[0029] The differential output shaft 4 is rotatably mounted on the housing 6 and is fixedly provided with a rotating gear 41 . The rotating gear 41 is meshed with the shift gear 31 .

[0030] In some embodiments, as shown in the attached Figure 5 As shown, the side walls of the adjusting gear 32 and the clutch disc sleeve 58 facing the elastic pin clutch are both provided with clutch holes that can be plugged into the elastic pin clutch 7.

[0031] In some embodiments, as shown in the attached Figure 3-5As shown, the spring-pin clutch 7 includes a clutch sleeve 33, a shift fork 34, a return spring 35, a transmission pin 36 and a pressure plate 37. A first positioning hole 38 is provided on the surface of the shift shaft 3. A positioning spring 39 is provided in the first positioning hole 38. A positioning steel ball 57 is provided on the top of the positioning spring 39. The clutch sleeve 33 is sleeved on the shift shaft 3, and the inner wall of the clutch sleeve 33 is provided with two groups of steel ball grooves arranged along the axial direction. The top of the positioning steel ball 57 is located in one of the steel ball grooves. The shift fork 34 is clamped on the clutch sleeve 33. The clutch sleeve 33 is provided with a plurality of second positioning holes 51 that pass through both ends. The pressure plate 37 is provided with There are two of them and they are separately arranged at both ends of the clutch sleeve 33. A transmission pin 36 is arranged in each second positioning hole 51, and the transmission pin is suitable for being inserted into the clutch hole. The multiple transmission pins 36 are divided into two groups; the left side of the transmission pin 36 of one group extends out of the second positioning hole 51 and the pressure plate 37 on the left side, and the right side of the transmission pin 36 of one group is provided with a return spring 35 abutting against the pressure plate 37 on the right side; the right side of the transmission pin 36 of the other group extends out of the second positioning hole 51 and the pressure plate 37 on the right side, and the left side of the transmission pin 36 of the other group is provided with a return spring 35 abutting against the pressure plate 37 on the left side.

[0032] In some embodiments, as shown in the attached Figure 3 As shown, the shifting device includes a hydraulic cylinder 53 and an oil pump 54. The hydraulic cylinder 53 is fixedly arranged on the outside of the box body 6, and a shifting rod 52 is arranged at the output end of the hydraulic cylinder 53. The shifting rod 52 is slidably arranged on the box body 6 and fixedly connected to the shift fork 34. The oil pump 54 is connected to the hydraulic cylinder 53.

[0033] The working principle of the present invention is as follows:

[0034] The entire automatic transmission is installed on the electric vehicle drive shaft, so that the differential output shaft 4 can be connected to the drive shaft. After the installation on the electric vehicle is completed, the power is transmitted to the output shaft 1, and the external motor rotates clockwise or counterclockwise, and the output shaft 1 distributes the power to the high-speed gear 11 and the low-speed gear 12 respectively;

[0035] When the vehicle moves forward, the oil pump 54 and the hydraulic cylinder 53 drive the lever 52 to move, so that the lever 52 drives the shift fork 34 to move, so that the clutch sleeve 33 is pushed right by the shift fork 34, and the transmission pin 36 is inserted into the clutch hole on the clutch disc sleeve 58. The vehicle starts, and the gearbox is in the low gear state. The output shaft 1 rotates clockwise, the low gear 12 transmits power to the linkage gear 21, the first drive gear 22 transmits power to the adjustment gear 32, and the shift gear 31 transmits power to the rotating gear 41. The low gear operation is completed. At this time, the rotating gear 41 turns to rotate counterclockwise, and the high gear 11 and the drive gear 59 are empty. When the vehicle accelerates to the high-speed gear state, the power motor and the output shaft 1 rotate counterclockwise in the opposite direction under the action of the controller, the high-speed gear 11 transmits power to the drive gear 59, and the shift gear 31 transmits power to the rotating gear 41, and the high-speed gear operation is completed. At this time, the rotating gear 41 turns to rotate counterclockwise, and the high-speed gear 11, the linkage gear 21, the first driving gear 22, and the adjusting gear 32 are idling; when the vehicle decelerates from the high-speed gear to the low-speed gear, the power motor and the output shaft 1 rotate clockwise in the opposite direction under the action of the controller, and the vehicle returns to the low-speed gear state for driving. The vehicle deceleration is completed, and the rotating gear 41 does not turn to rotate counterclockwise.

[0036] When the vehicle reverses, the high-speed gear 11 rotates counterclockwise under the action of the controller, the hydraulic shift device 10, etc. At this time, the spring clutch 7 slides to the left on the shift shaft 3 and separates from the clutch plate sleeve 58. The transmission pin 36 is inserted into the clutch hole on the adjusting gear 32. The output shaft 1 rotates counterclockwise, the low-speed gear 12 transmits power to the linkage gear 21, the first drive gear 22 transmits power to the adjusting gear 32, and the shift gear 31 transmits power to the rotating gear 41. The rotating gear 41 rotates clockwise, and the reversing is completed. The high-speed gear 11 and the drive gear 59 are idling at this time.

[0037] It has been clearly explained in this embodiment that a two-speed automatic transmission for an electric vehicle is used for use in electric vehicles, and is therefore limited to use in electric vehicles. Without other descriptions or limitations, it will not be used for products other than electric vehicles. Therefore, this technical field only protects how to use it in electric vehicles. The technical solution solved by this embodiment is fully adapted to the name of a two-speed automatic transmission for an electric vehicle and is associated with it.

[0038] Finally, a few points should be explained: First, in the description of this application, it should be noted that, unless otherwise specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, which may refer to mechanical connection or electrical connection, or internal communication between two components, or direct connection. "upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may change;

[0039] Secondly: In the drawings of the embodiments disclosed in the present invention, only the structures related to the embodiments disclosed in the present invention are involved, and other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of the present invention can be combined with each other;

[0040] Finally: 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, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A two-speed automatic transmission for an electric vehicle, comprising an output shaft (1) and a housing (6), wherein the output shaft (1) is rotatably disposed in the housing (6), and a high-speed gear (11) and a low-speed gear (12) are fixed to the outside of the output shaft (1). Features: A speed change assembly is provided on one side of the outer wall of the low gear (12), and the speed change assembly comprises: A bridge shaft (2) is rotatably mounted on the housing (6), a linkage gear (21) and a first drive gear (22) being fixedly mounted on the bridge shaft (2), and the linkage gear (21) is meshed with a low gear (12); A shift shaft (3) is rotatably mounted on the housing (6), a shift gear (31) being fixedly mounted on the shift shaft (3), and an adjusting gear (32) and a clutch disc sleeve (58) being rotatably sleeved on the shift shaft (3), a first one-way device (55) being arranged between the adjusting gear (32) and the shift shaft (3), a second one-way device (56) being sleeved on the outer side of the clutch disc sleeve (58), a driving gear (59) being arranged on the outer side of the second one-way device (56), the adjusting gear (32) being meshed with the first driving gear (22), and the driving gear (59) being meshed with the high gear (11); The spring pin clutch (7) is slidably sleeved on the shift shaft (3), is in transmission connection with a shifting device, and is located between the adjusting gear (32) and the clutch disc sleeve (58). When the spring pin clutch (7) slides along the shift shaft (3), it can be inserted into the adjusting gear (32) or the clutch disc sleeve (58); the differential output shaft (4) is rotatably arranged in the box body (6) and is fixedly provided with a rotating gear (41). The rotating gear (41) meshes with the shift gear (31). The spring pin clutch (7) includes a clutch sleeve (33), a fork (34), a return spring (35), a transmission pin (36) and a pressure plate (37). A first positioning hole (38) is formed on the surface of the shift shaft (3), a positioning spring (39) is arranged in the first positioning hole (38), a positioning steel ball (57) is arranged at the top of the positioning spring (39). The clutch sleeve (33) is sleeved on the shift shaft (3), and two groups of steel ball grooves arranged axially are formed on the inner wall of the clutch sleeve (33). The top of the positioning steel ball (57) is located in one of the steel ball grooves. The fork (34) is clamped on the clutch sleeve (33). The clutch sleeve (33) is provided with a plurality of second positioning holes (51) penetrating through both ends. The pressure plates (37) are provided in two and are respectively arranged at both ends of the clutch sleeve (33). A transmission pin (36) is arranged in each of the second positioning holes (51). The transmission pin is adapted to be inserted into the clutch hole. The plurality of transmission pins (36) are divided into two groups. The left sides of the transmission pins (36) in one group extend out of the second positioning hole (51) and the left pressure plate (37), and a return spring (35) abutted against the right pressure plate (37) is arranged on the right side of the transmission pins (36) in this group; the right sides of the transmission pins (36) in the other group extend out of the second positioning hole (51) and the right pressure plate (37), and a return spring (35) abutted against the left pressure plate (37) is arranged on the left side of the transmission pins (36) in the other group.

2. The two-speed automatic transmission for an electric vehicle according to claim 1, characterized in that: Clutch holes that can be inserted with the spring pin clutch (7) are provided on the side walls of the adjusting gear (32) and the clutch disc sleeve (58) facing the spring pin clutch.

3. The two-speed automatic transmission for an electric vehicle according to claim 1, characterized in that: The shifting device includes a hydraulic cylinder (53) and an oil pump (54). The hydraulic cylinder (53) is fixedly arranged on the outer side of the box body (6), and a shift lever (52) is arranged at the output end of the hydraulic cylinder (53). The shift lever (52) is slidably arranged in the box body (6) and is fixedly connected with the fork (34). The oil pump (54) is connected with the hydraulic cylinder (53).

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