Planetary reducer shift mechanism and control method thereof, two-gear reduction box

Abstract

The present application belongs to the field of vehicle manufacturing, and particularly relates to a planetary reducer shifting mechanism and a control method thereof, and a two-gear reduction gearbox, which comprises a shift fork unit and first and second synchronizers arranged on the same central axis; the first and second synchronizers are synchronously reciprocated along the central axis direction by the shift fork unit, so as to simultaneously connect the input shaft and the sun gear of the planetary reducer and synchronously connect the output shaft and the planet carrier of the planetary reducer to enter the low gear; or after disconnecting the input shaft and the sun gear and synchronously disconnecting the output shaft and the planet carrier, the input shaft and the output shaft are connected to enter the high gear; the existing planetary reducer shifting mechanism cannot realize the driving shifting while solving the problem of the planetary reducer idling at the high gear, which reduces the transmission efficiency and increases the operation noise, and cannot meet the requirements of the planetary reducer of the electric vehicle.

Description

Technical Field

[0001] This invention belongs to the field of vehicle manufacturing, and specifically relates to a planetary reducer shifting mechanism and its control method, and a two-speed reduction gearbox. Background Technology

[0002] Planetary reducers are common components in automotive transmission systems, offering three gears: high, neutral, and low. In existing planetary reducer shifting technologies, while traditional vehicles employ double sliding sleeve shifting mechanisms to prevent the planetary reducer from rotating in high gears, thus improving transmission efficiency and reducing noise, the two sliding sleeves in these mechanisms cannot operate synchronously. This means that while connecting the sun gear to the input shaft, it's impossible to simultaneously connect the first planet carrier and the first output shaft. If shifting from high to low gear during vehicle operation, a step-by-step connection is required. However, the initial torque needed to simultaneously drive the sun gear, planet gears, and first planet carrier is too high. The sliding gear sleeve makes it difficult to synchronize the rotational speed of the sun gear with the input shaft or the rotational speed of the first planetary carrier with the first output shaft. Forcibly shifting from a high gear to a low gear can easily cause gear collision, resulting in the sun gear and input shaft not being able to connect or the planetary carrier and output shaft not being able to connect. Therefore, vehicles using a double sliding gear sleeve shifting mechanism need to stop to shift gears when needed. In the existing technology of electric vehicle gearboxes, a single synchronizer is also used for shifting planetary reducers, which can achieve shifting during driving. However, the planetary reducer is idling in high gear, resulting in reduced transmission efficiency and increased operating noise.

[0003] When planetary reducers are used in electric vehicles, they must achieve gear shifting while driving, and the transmission efficiency and noise level at high gears also require close attention. Clearly, the planetary reducer shifting mechanisms mentioned above all fail to address the issues of reduced transmission efficiency and increased operating noise caused by the planetary reducer idling at high gears while simultaneously achieving gear shifting, thus failing to meet the requirements for planetary reducers in electric vehicles. Summary of the Invention

[0004] This invention provides a planetary reducer shifting mechanism and its control method, as well as a two-speed gearbox, which solves the problem that existing planetary reducer shifting mechanisms cannot simultaneously achieve gear shifting while driving, and also prevent the planetary reducer from idling at high speeds, resulting in reduced transmission efficiency and increased operating noise.

[0005] The technical solution adopted in this invention is: including a shift fork unit and a first synchronizer and a second synchronizer arranged on the same central axis;

[0006] The first synchronizer is a double-sided synchronizer, installed on the input shaft of the planetary reducer. The side of the first synchronizer away from the second synchronizer is used to connect the input shaft to the sun gear of the planetary reducer; the side of the first synchronizer closer to the second synchronizer is used to connect the input shaft to the first output shaft of the planetary reducer.

[0007] The second synchronizer is a single-sided synchronizer, which is installed on the first output shaft. The side of the second synchronizer closer to the first synchronizer is used to connect the first output shaft to the first planet carrier of the planetary reducer.

[0008] The shift fork unit is used to shift the first synchronizer and the second synchronizer, so that the first synchronizer and the second synchronizer move synchronously back and forth along the central axis, so as to connect the input shaft and the sun gear at the same time, and simultaneously connect the first output shaft and the first planetary carrier; or disconnect the connection between the input shaft and the sun gear, and simultaneously disconnect the connection between the first output shaft and the first planetary carrier, and then connect the input shaft and the first output shaft.

[0009] The central axes of the input shaft, the first output shaft, the sun gear, the first planetary carrier, the first synchronizer, and the second synchronizer coincide.

[0010] The above technical solution, by setting the shift fork unit, enables both the first synchronizer and the second synchronizer to reciprocate synchronously along the central axis. When the first synchronizer moves away from the second synchronizer, the second synchronizer also moves towards the first synchronizer synchronously. This allows the first synchronizer to connect the input shaft to the sun gear while the second synchronizer simultaneously connects the first output shaft to the first planetary carrier, enabling the vehicle to enter a low gear. By utilizing the input shaft and the first synchronizer to drive the stationary sun gear to rotate synchronously, and by utilizing the first output shaft and the second synchronizer to drive the stationary first planetary carrier to rotate synchronously, the initial torque required to drive the sun gear, planet gears, and first planetary carrier to rotate simultaneously is reduced, thereby enabling the shifting from a high gear to a low gear during vehicle operation.

[0011] As the first synchronizer moves closer to the second synchronizer, the second synchronizer also moves further away from the first synchronizer. This disconnects the input shaft from the sun gear and causes the second synchronizer to simultaneously disconnect the first output shaft from the first planetary carrier. Then, the first synchronizer connects the input shaft to the first output shaft, allowing the vehicle to enter a high-speed gear. This enables the vehicle to shift from a low-speed to a high-speed gear while driving. Furthermore, when the vehicle is in the high-speed gear, both the sun gear and the first planetary carrier are disconnected from the input shaft and also from the first output shaft. This prevents the planetary reducer from rotating in high-speed gears, thus solving the problem of reduced transmission efficiency and increased operating noise caused by the planetary reducer spinning idling in high-speed gears.

[0012] Simultaneously, when the first synchronizer disconnects the input shaft from the sun gear, the second synchronizer disconnects the first output shaft from the first planetary carrier, and the first synchronizer is also not connected to the input shaft from the first output shaft, it is in neutral.

[0013] Furthermore, the shift fork unit includes a first shift fork assembly for shifting the first synchronizer and a second shift fork assembly for shifting the second synchronizer, wherein the first shift fork assembly is fixedly connected to the second synchronizer or the second shift fork assembly is fixedly connected to the first synchronizer.

[0014] The above technical solution proposes a way of setting the shift fork unit. By fixing the second shift fork assembly used to move the second synchronizer to the first synchronizer, or fixing the first shift fork assembly used to move the first synchronizer to the second synchronizer, it can be realized that the first synchronizer and the second synchronizer can move synchronously back and forth along the central axis direction through the first shift fork assembly or the second shift fork assembly.

[0015] Furthermore, the first shift fork assembly is fixedly connected to the second synchronizer; the first shift fork assembly includes a shift fork body and at least one connector, the connector being fixedly connected to the second synchronizer, and the shift fork body being fixedly connected to the connector.

[0016] Furthermore, the first synchronizer includes a first gear sleeve and a first gear hub; the second synchronizer includes a second gear sleeve and a second gear hub;

[0017] The inner circumferential surface of the first gear sleeve is splined with the outer circumferential surface of the first gear hub, and the inner circumferential surface of the second gear sleeve is splined with the outer circumferential surface of the second gear hub; the first gear hub is mounted on the input shaft, and the side of the first gear sleeve away from the second synchronizer is used to connect the input shaft to the sun gear of the planetary reducer; the side of the first gear sleeve close to the second synchronizer is used to connect the input shaft to the first output shaft.

[0018] The second gear hub is mounted on the first output shaft, and the second gear sleeve is used to connect the first output shaft to the first planetary carrier on the side near the first synchronizer.

[0019] A side plate is provided on the side of the second gear sleeve away from the first synchronizer. The connector is arranged parallel to the central axis. The first end of the connector is fixedly connected to the side plate. A first through hole is opened on the second gear hub to cooperate with the connector. The second end of the connector passes through the corresponding first through hole and is fixedly connected to the shift fork body. A second through hole is opened on the side plate, and the first output shaft passes through the second through hole through the side plate.

[0020] The outer circumferential surface of the first tooth sleeve is provided with a first shift fork groove arranged in the circumferential direction. The shift fork body cooperates with the first shift fork groove so that when the second shift fork assembly moves the second tooth sleeve reciprocally along the central axis, the shift fork body synchronously drives the first tooth sleeve to reciprocate along the central axis.

[0021] Furthermore, the number of the connectors is at least two, and each connector is evenly distributed circumferentially around the central axis;

[0022] The shift fork body is annular and installed in the first shift fork groove. The inner side of the shift fork body is in clearance fit with the bottom of the first shift fork groove, so that the shift fork body can rotate relative to the first synchronizer around the central axis.

[0023] Furthermore, the first shift fork assembly also includes a retaining ring. The second end of the connector is provided with a stepped portion. The shift fork body is provided with a third through hole that mates with the stepped portion. The stepped portion passes through the corresponding third through hole to restrict the shift fork body from sliding on the stepped portion toward the side plate. The stepped portion is provided with a retaining groove that extends circumferentially around the central axis. The retaining ring is sleeved on the outside of each connector and installed in the retaining groove. The inner side of the retaining ring mates with the bottom of the retaining groove, and the outer side of the retaining ring extends out of the retaining groove, so that the side of the retaining ring near the side plate contacts the side of the shift fork body away from the side plate to restrict the shift fork body from sliding away from the side plate on the stepped portion. The retaining ring fixes the shift fork body to the stepped portion.

[0024] By providing the stepped portion, the third through hole, and the retaining ring, the fork body and the connecting member are detachably and fixedly connected, which facilitates the assembly and disassembly of the components in the first fork assembly.

[0025] Furthermore, the shift fork body includes multiple arc-shaped components, which are sequentially and detachably fixedly connected along the circumference of the central axis to form a ring.

[0026] By setting the shift fork body as a plurality of arc-shaped parts that are fixedly connected circumferentially along the central axis, and the fixed connection between each arc-shaped part being detachable in sequence, the installation and removal of the shift fork body in the first shift fork groove is facilitated.

[0027] Furthermore, the number of arc-shaped components is the same as the number of connecting components. One end of each arc-shaped component has a first connector, and the other end has a second connector. Each first connector of an arc-shaped component mates with the second connector of an adjacent arc-shaped component. Each first connector has a first mounting hole, and each second connector has a second mounting hole. The third through hole is formed by the first mounting hole on the first connector and the second mounting hole on the mating second connector. The stepped portion passes through its corresponding first and second mounting holes. The retaining ring mates with the stepped portion to securely connect the corresponding first and second connectors.

[0028] The present invention also provides a transmission, including a planetary reducer and a planetary reducer shifting mechanism provided according to the present invention.

[0029] The planetary reducer includes: a housing, a sun gear, planet gears, a first planet carrier, a ring gear, and an input shaft and a first output shaft arranged coaxially. The ring gear is fixedly connected to the housing. The sun gear has a central hole. The central hole, the input shaft, and the central axis of the sun gear all coincide. The input shaft passes through the central hole and can rotate freely relative to the sun gear around its central axis.

[0030] The present invention also provides a two-speed gearbox, including a reduction mechanism, a differential, a planetary reducer, and a planetary reducer shifting mechanism provided according to the present invention.

[0031] The first output shaft of the planetary reducer is connected to the second planetary carrier of the differential.

[0032] The reduction mechanism includes an input gear, an idler gear, and an output gear. The input gear is mounted on the second output shaft of the electric vehicle's drive motor. The idler gear meshes with the input gear. The output gear is mounted on the input shaft and meshes with the idler gear.

[0033] The planetary reducer includes: a housing, a sun gear, planet gears, a first planet carrier, a ring gear, and an input shaft and a first output shaft arranged coaxially. The ring gear is fixedly connected to the housing. The sun gear has a central hole. The central hole, the input shaft, and the central axis of the sun gear all coincide. The input shaft passes through the central hole and can rotate freely relative to the sun gear around its central axis.

[0034] The present invention also provides a vehicle including a planetary gear reducer shifting mechanism provided according to the present invention.

[0035] On the other hand, the present invention also provides a control method for the above-mentioned planetary reducer shifting mechanism, including a first shifting control method for switching the vehicle from a high gear to a low gear while driving and a second shifting control method for switching the vehicle from a low gear to a high gear while driving.

[0036] The first shift control method includes the following steps:

[0037] Step 1: Synchronously move the first synchronizer and the second synchronizer through the shift fork unit, so that the second synchronizer moves closer to the first synchronizer while the first synchronizer moves away from the second synchronizer.

[0038] Based on the movement of the synchronizer, the first synchronizer is moved closer to the second synchronizer, disconnecting the first output shaft of the planetary reducer from the input shaft of the planetary reducer. This allows the first synchronizer to be connected only to the input shaft, and the second synchronizer to be connected only to the first output shaft, thus shifting the vehicle from high gear to neutral.

[0039] Step 2: After the vehicle is switched to neutral, the shift fork unit continues to synchronously move the first synchronizer and the second synchronizer, so that the second synchronizer moves further toward the first synchronizer while the first synchronizer moves synchronously away from the second synchronizer.

[0040] Based on the further movement of the synchronizer, the side of the first synchronizer away from the second synchronizer connects the input shaft and the sun gear, while the side of the second synchronizer close to the first synchronizer simultaneously connects the first output shaft and the first planet carrier of the planetary reducer. This allows the power transmitted by the input shaft to be transmitted to the first output shaft after being reduced in speed and torque increased by the sun gear and the first planet carrier, and the vehicle shifts from neutral to low gear.

[0041] The second shift control method includes the following steps:

[0042] Step 1: Synchronously move the first synchronizer and the second synchronizer through the shift fork unit, so that the second synchronizer moves away from the first synchronizer while the first synchronizer moves towards the second synchronizer.

[0043] Based on the movement of the synchronizer, the first synchronizer is disconnected from the input shaft and the sun gear on the side away from the second synchronizer, while the second synchronizer is disconnected from the first output shaft and the first planetary carrier on the side closer to the first synchronizer. This makes the first synchronizer only connected to the input shaft and the second synchronizer only connected to the first output shaft, so that the vehicle shifts from low gear to neutral.

[0044] Step 2: After the vehicle is switched to neutral, the shift fork unit continues to synchronously move the first synchronizer and the second synchronizer, so that the second synchronizer moves away from the first synchronizer while the first synchronizer moves closer to the second synchronizer.

[0045] Further movement of the synchronizer allows the first synchronizer to connect the first output shaft and the input shaft on the side closer to the second synchronizer, while the second synchronizer is only connected to the first output shaft. This allows the power transmitted by the input shaft to be directly transmitted to the first output shaft via the first synchronizer. When the vehicle shifts from neutral to high gear, the sun gear and the first planetary carrier are disconnected from the input shaft and also from the first output shaft when the vehicle is in high gear.

[0046] Furthermore, the method of synchronously moving the first synchronizer and the second synchronizer through the shift fork unit includes:

[0047] The shift fork unit includes a first shift fork assembly for shifting a first synchronizer and a second shift fork assembly for shifting a second synchronizer;

[0048] The second shift fork assembly is fixedly connected to the first synchronizer to constrain the second shift fork assembly to move synchronously with the first synchronizer, so that while the first shift fork assembly moves the first synchronizer, the second shift fork assembly moves the second synchronizer synchronously with the first synchronizer.

[0049] Alternatively, the first shift fork assembly can be fixedly connected to the second synchronizer to constrain the first shift fork assembly and the second synchronizer to move synchronously, so that while the second shift fork assembly moves the second synchronizer, the first shift fork assembly moves the first synchronizer and the second synchronizer synchronously. Attached Figure Description

[0050] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0051] Figure 1 This is a simplified kinematic diagram of the planetary reducer shifting mechanism in an embodiment of the present invention;

[0052] Figure 2 This is an exploded view of the assembly of the first toothed sleeve, the second toothed sleeve, and the second toothed hub in an embodiment of the present invention.

[0053] Figure 3 This is a schematic diagram of the arc-shaped component in an embodiment of the present invention;

[0054] Figure 4 This is a simplified kinematic diagram of the two-speed reduction gearbox of the present invention;

[0055] Wherein: 1—First synchronizer, 2—Second synchronizer, 3—First shift fork assembly, 4—Second shift fork assembly, 5—Planetary reducer, 6—Reduction mechanism, 7—Differential gear

[0056] 11—First gear hub, 12—First gear sleeve;

[0057] 121—First shift fork groove;

[0058] 21—Second gear hub, 22—Second gear sleeve;

[0059] 211—First through hole;

[0060] 221—Side plate, 222—Second through hole, 223—Second shift fork groove;

[0061] 31—Connector, 32—Shift fork body, 33—Snap ring;

[0062] 311—Step section, 312—Slot;

[0063] 321—Arc-shaped component;

[0064] 3211—First connector, 3212—First mounting hole, 3213—Second connector, 3214—Second mounting hole;

[0065] 51—Input shaft, 52—Sun gear, 53—First planet carrier, 54—First output shaft;

[0066] 61—Input gear, 62—Idle gear, 63—Output gear;

[0067] 71—Second planetary carrier, 72—Differential planetary gear, 73—Half-shaft gear, 74—First half-shaft, 75—Second half-shaft. Detailed Implementation

[0068] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0069] Example 1

[0070] This embodiment 1 provides a planetary reducer shifting mechanism, including a shift fork unit and a first synchronizer 1 and a second synchronizer 2 arranged on the same central axis;

[0071] The first synchronizer 1 is a double synchronizer and is installed on the input shaft 51 of the planetary reducer 5. The side of the first synchronizer 1 away from the second synchronizer 2 is used to connect the input shaft 51 to the sun gear 52 of the planetary reducer 5; the side of the first synchronizer 1 close to the second synchronizer 2 is used to connect the input shaft 51 to the first output shaft 54 ​​of the planetary reducer 5.

[0072] The second synchronizer 2 is a single-sided synchronizer and is installed on the first output shaft 54. The side of the second synchronizer 2 closest to the first synchronizer 1 is used to connect the first output shaft 54 ​​to the first planet carrier 53 of the planetary reducer 5.

[0073] The shift fork unit is used to shift the first synchronizer 1 and the second synchronizer 2, so that the first synchronizer 1 and the second synchronizer 2 move synchronously back and forth along the central axis, so as to connect the input shaft 51 and the sun gear 52 at the same time, and simultaneously connect the first output shaft 54 ​​and the first planetary carrier 53; or disconnect the connection between the input shaft 51 and the sun gear 52, and simultaneously disconnect the connection between the first output shaft 54 ​​and the first planetary carrier 53, and then connect the input shaft 51 and the first output shaft 54.

[0074] Among them, the central axes of the first synchronizer 1, the second synchronizer 2, the input shaft 51, the sun gear 52, the first planetary carrier 53, and the first output shaft 54 ​​all coincide; therefore, the term "central axis" in the text refers to the axis that coincides with the central axis of the first synchronizer 1, the second synchronizer 2, the input shaft 51, the sun gear 52, the first planetary carrier 53, and the first output shaft 54.

[0075] The above technical solution, by setting up a shift fork unit, enables the first synchronizer 1 and the second synchronizer 2 to reciprocate synchronously along the central axis; when the first synchronizer 1 moves away from the second synchronizer 2, the second synchronizer 2 also moves synchronously towards the first synchronizer 1, thereby enabling the first synchronizer 1 to connect the input shaft 51 and the sun gear 52 while the second synchronizer 2 synchronously connects the first output shaft 54 ​​and the first planetary carrier 53, so that the vehicle enters a low gear.

[0076] While the input shaft 51 and the first synchronizer 1 drive the stationary sun gear 52 to rotate synchronously, the first output shaft 54 ​​and the second synchronizer 2 drive the stationary first planetary carrier 53 to rotate synchronously. By simultaneously driving the sun gear 52 and the first planetary carrier 53 to rotate through the first synchronizer 1 and the second synchronizer 2, compared to driving the sun gear 52 to rotate and then driving the first planetary carrier 53 to rotate, or driving the first planetary carrier 53 to rotate and then driving the sun gear 52 to rotate, the initial torque borne by each component when driving the sun gear 52, planet gears and the first planetary carrier 53 of the planetary reducer 5 is reduced. This solves the problem that when using the existing double sliding gear shifting mechanism, it is easy for teeth to collide when shifting from high gear to low gear during vehicle operation, resulting in the sun gear and input shaft not being able to connect or the planetary carrier and output shaft not being able to connect. Thus, it is possible to shift from high gear to low gear during vehicle operation.

[0077] When the first synchronizer 1 moves closer to the second synchronizer 2, the second synchronizer 2 also moves away from the first synchronizer 1. This disconnects the first synchronizer 1 from the input shaft 51 and the sun gear 52, and causes the second synchronizer 2 to simultaneously disconnect the first output shaft 54 ​​from the first planetary carrier 53. Then, the first synchronizer 1 connects the input shaft 51 and the first output shaft 54, allowing the vehicle to enter a high-speed gear. This enables the vehicle to switch from a low-speed gear to a high-speed gear while driving. When the vehicle is in a high-speed gear, neither the sun gear 52 nor the first planetary carrier 53 of the planetary reducer 5 is connected to external parts. This ensures that the planetary reducer 5 does not rotate in the high-speed gear, solving the problem of reduced transmission efficiency and increased operating noise caused by the planetary reducer spinning idly in the high-speed gear when using a single synchronizer for gear shifting in the prior art.

[0078] At the same time, when the first synchronizer 1 disconnects the input shaft 51 from the sun gear 52, and the second synchronizer 2 disconnects the first output shaft 54 ​​from the first planetary carrier 53, and the first synchronizer 1 is not connected to the input shaft 51 from the first output shaft 54, it is in neutral, that is, neutral is located between high speed and low speed.

[0079] Preferably, in this embodiment 1, as Figure 1 As shown, the shift fork unit includes a first shift fork assembly 3 for shifting the first synchronizer 1 and a second shift fork assembly 4 for shifting the second synchronizer 2.

[0080] In order to enable both the first synchronizer 1 and the second synchronizer 2 to move synchronously along the central axis under the action of the shift fork unit, there are multiple ways to set the first shift fork assembly 3 and the second shift fork assembly 4, including but not limited to: fixing the first shift fork assembly 3 to the second synchronizer 2 or fixing the second shift fork assembly 4 to the first synchronizer 1.

[0081] Specifically, the above technical solution proposes a way of setting up a shift fork unit. By fixing the second shift fork assembly 4 for moving the second synchronizer 2 to the first synchronizer 1, or fixing the first shift fork assembly 3 for moving the first synchronizer 1 to the second synchronizer 2, the first synchronizer 1 and the second synchronizer 2 can be synchronously reciprocated along the central axis direction by the first shift fork assembly 3 or the second shift fork assembly 4.

[0082] Preferably, in this embodiment 1, as Figure 1 As shown, the first shift fork assembly 3 is fixedly connected to the second synchronizer 2; as Figure 2 As shown, the first shift fork assembly 3 includes a shift fork body 32 and at least one connector 31. The connector 31 is fixedly connected to the second synchronizer 2, and the shift fork body 32 is fixedly connected to the connector 31.

[0083] like Figure 1 and Figure 2 As shown, the first synchronizer 1 includes a first gear sleeve 12 and a first gear hub 11; the second synchronizer 2 includes a second gear sleeve 22 and a second gear hub 21.

[0084] The inner circumferential surface of the first gear sleeve 12 is splined with the outer circumferential surface of the first gear hub 11, and the inner circumferential surface of the second gear sleeve 22 is splined with the outer circumferential surface of the second gear hub 21; the first gear hub 11 is mounted on the input shaft 51, and the side of the first gear sleeve 12 away from the second synchronizer 2 is used to connect the input shaft 51 to the sun gear 52 of the planetary reducer 5; the side of the first gear sleeve 12 close to the second synchronizer 2 is used to connect the input shaft 51 to the first output shaft 54;

[0085] The second gear hub 21 is mounted on the first output shaft 54, and the second gear sleeve 22 is used to connect the first output shaft 54 ​​to the first planetary carrier 53 on the side near the first synchronizer 1.

[0086] A side plate 221 is provided on the side of the second gear sleeve 22 away from the first synchronizer 1. A connecting member 31 is arranged parallel to the central axis. The first end of the connecting member 31 is fixedly connected to the side plate 221. A first through hole 211 that mates with the connecting member 31 is provided on the second gear hub 21. The second end of the connecting member 31 passes through the corresponding first through hole 211 and is fixedly connected to the shift fork body 32. A second through hole 222 is provided on the side plate 221. The first output shaft 54 ​​passes through the side plate 221 through the second through hole 222.

[0087] The outer circumferential surface of the first tooth sleeve 12 is provided with a first shift fork groove 121 arranged circumferentially. The shift fork body 32 cooperates with the first shift fork groove 121, so that when the second shift fork assembly 4 moves the second tooth sleeve 22 back and forth along the central axis (through the second shift fork assembly 4 cooperating with the second shift fork groove 223 provided on the outer circumferential surface of the second tooth sleeve 22, the second shift fork groove is arranged circumferentially along the second tooth sleeve 22), the shift fork body 32 simultaneously drives the first tooth sleeve 12 to move back and forth along the central axis.

[0088] It should be noted that in this embodiment 1, the synchronizers used (i.e., the first synchronizer 1 and the second synchronizer 2) are both conventional synchronizers. To more clearly illustrate the connection relationship between the first synchronizer 1, the second synchronizer 2, and the first shift fork assembly 3, therefore... Figure 2 The synchronizer ring, the groove on the inner side of the gear sleeve (i.e., the first gear sleeve 12 and the second gear sleeve 22), the groove on the gear hub (i.e., the first gear hub 11 and the second gear hub 21), and other components such as the slider are not shown in the diagram.

[0089] There are various ways to arrange the shift fork body 32 and the connecting member, as long as the following conditions are met:

[0090] 1. The shift fork body 32 is fixedly connected to the side plate 221 by a connecting component;

[0091] 2. The rotation of the connecting component with the second toothed sleeve 22 does not affect the rotation of the first toothed sleeve 12;

[0092] 3. The shift fork body 32 is installed in the first shift fork groove 121 and can rotate freely in the first shift fork groove 121 (rotating with the connecting component around the central axis of the first synchronizer 1 and the second synchronizer 2, so it actually rotates around the central axis of the first gear sleeve 12).

[0093] Therefore, preferably, in this embodiment 1, as follows: Figure 2As shown, the number of connectors 31 is at least two (in this embodiment 1, the number of connectors 31 is four), and each connector 31 is evenly distributed around the central axis in the circumferential direction;

[0094] The shift fork body 32 is annular and installed in the first shift fork groove 121. The inner side of the shift fork body 32 is in clearance fit with the bottom of the first shift fork groove 121, so that the shift fork body 32 can rotate relative to the first synchronizer 1 around the central axis.

[0095] To facilitate the assembly and disassembly of the components in the first shift fork assembly 3, preferably, in this embodiment 1, as follows: Figure 2 As shown, the first shift fork assembly 3 also includes a retaining ring 33. The second end of the connector 31 is provided with a stepped portion 311. The shift fork body 32 is provided with a third through hole that mates with the stepped portion 311. The stepped portion 311 passes through the corresponding third through hole to restrict the shift fork body 32 from sliding on the stepped portion 311 toward the side plate 221. The stepped portion 311 is provided with a retaining groove 312 that extends circumferentially around the central axis. The retaining ring 33 is sleeved on the outside of each connector 31 and installed in the retaining groove 312. The inner side of the retaining ring 33 mates with the bottom of the groove 312, and the outer side of the retaining ring 33 extends out of the retaining groove 312, so that the side of the retaining ring 33 near the side plate 221 contacts the side of the shift fork body 32 away from the side plate 221 to restrict the shift fork body 32 from sliding away from the side plate 221 on the stepped portion 311. The retaining ring 33 fixes the shift fork body 32 to the stepped portion 311.

[0096] By providing the step portion 311, the third through hole, and the retaining ring 33, the shift fork body 32 and the connecting member 31 are detachably and fixedly connected, which facilitates the assembly and disassembly of each component in the first shift fork assembly 3.

[0097] To facilitate the installation of the shift fork body 32 within the first shift fork groove 121, preferably, in this embodiment 1, as follows: Figure 2 , Figure 3 As shown, the shift fork body 32 includes multiple arc-shaped parts 321, which are detachably and fixedly connected in sequence along the circumference of the central axis to form a ring.

[0098] By setting the shift fork body 32 as a plurality of arc-shaped parts 321 that are fixedly connected in sequence along the central axis, and the fixed connection between each arc-shaped part 321 is detachable, the installation and removal of the shift fork body 32 in the first shift fork groove 121 is facilitated.

[0099] To further facilitate the assembly and disassembly of the components in the first shift fork assembly 3, and to facilitate the installation of the shift fork body 32 in the first shift fork slot 121.

[0100] Preferably, in this embodiment 1, as Figure 2, Figure 3 As shown, the number of arc-shaped parts 321 and connecting parts 31 is the same. One end of the arc-shaped part 321 is provided with a first connector 3211, and the other end of the arc-shaped part 321 is provided with a second connector 3213. The first connector 3211 of the arc-shaped part 321 mates with the second connector 3213 of the adjacent arc-shaped part 321. The first connector 3211 is provided with a first mounting hole 3212, and the second connector 3213 is provided with a second mounting hole 3214. The third through hole is formed by the first mounting hole 3212 on the first connector 3211 and the second mounting hole 3214 on the mating second connector 3213. The stepped part 311 passes through its corresponding first mounting hole 3212 and second mounting hole 3214. The retaining ring 33 mates with the stepped part 311 to fix the corresponding first connector 3211 and second connector 3213 together.

[0101] By ensuring that the number of arc-shaped parts 321 and connecting parts 31 are the same, and by providing a first connector 3211 and a second connector 3213 at both ends of the arc-shaped parts 321, the first mounting holes 3212 on the first connectors 3211 of the arc-shaped parts 321 are matched with the second mounting holes 3214 on the second connectors 3213 of the adjacent arc-shaped parts 321. The stepped portion 311 passes through its corresponding first mounting hole 3212 and second mounting hole 3214. The retaining ring 33 cooperates with the stepped portion 311 to fix the corresponding first connectors 3211 and second connectors 3213, further facilitating the assembly and disassembly of the first shift fork assembly 3, and further facilitating the installation and disassembly of the shift fork body 32 in the first shift fork groove 121.

[0102] This embodiment 1 also provides a transmission, such as Figure 1 and Figure 4 As shown, it includes a planetary reducer 5 and the planetary reducer shifting mechanism provided in this embodiment 1.

[0103] The structure of the planetary reducer 5 is a conventional technology. In this embodiment 1, for example... Figure 1 and Figure 4 As shown, the planetary reducer 5 includes: a housing, a sun gear 52, planet gears, a first planet carrier 53, a gear ring, and an input shaft 51 and a first output shaft 54 ​​arranged coaxially. The gear ring is fixedly connected to the housing. The sun gear 52 is provided with a central hole. The central hole, the input shaft 51 and the central axis of the sun gear 52 are all coincident. The input shaft 51 passes through the central hole and can rotate freely about the central axis of the sun gear 52 relative to the sun gear 52.

[0104] This embodiment 1 also provides a two-speed reduction gearbox, including a reduction mechanism 6, a differential 7, a planetary reducer 5, and the planetary reducer shifting mechanism provided in this embodiment 1. The first output shaft 54 ​​of the planetary reducer 5 is connected to the second planetary carrier 71 of the differential 7.

[0105] The reduction mechanism 6 includes an input gear 61, an idler gear 62, and an output gear 63. The input gear 61 is mounted on the second output shaft of the electric vehicle's drive motor. The idler gear 62 is meshed with the input gear 61. The output gear 63 is mounted on the input shaft 51 and meshes with the idler gear 62.

[0106] The differential 7 has a conventional structure and can be selected from various types of existing differentials. It is only necessary to connect the first output shaft 54 ​​to the planetary carrier of the differential.

[0107] For example, but not limited to, in this embodiment 1, such as Figure 4 As shown, the differential 7 includes a second planetary carrier 71, a differential planetary gear 72, a half-shaft gear 73, a first half-shaft 74, and a second half-shaft 75.

[0108] When the planetary reducer shifting mechanism is in high gear, power is input from the input gear 61 of the reduction mechanism 6, output from the output gear 63 to the input shaft 51, and then transmitted sequentially through the first synchronizer 1 to the first output shaft 54, the second planetary carrier 71, the differential planetary gear 72, and the half-shaft gear 73. The power is then transmitted through the half-shaft gear 73 to the first half-shaft 74 and the second half-shaft 75 for output. This power transmission does not pass through the sun gear 52, planetary gears, and first planetary carrier 53 of the planetary reducer 5; therefore, the sun gear 52, planetary gears, and first planetary carrier 53 of the planetary reducer 5 do not rotate.

[0109] When the planetary reducer shifting mechanism is in neutral, the first synchronizer 1 disconnects the input shaft 51 from the sun gear 52, the second synchronizer 2 disconnects the first output shaft 54 ​​from the first planetary carrier 53, and the first synchronizer 1 is also not connected between the input shaft 51 and the first output shaft 54; there is no connection between the reduction mechanism 6, the planetary reducer 5, and the differential 7, and there is no power output. At the same time, the motion of the car fed back to the second gear reducer from the first half-shaft 74 and the second half-shaft 75 will only be transmitted to the first output shaft 54 ​​and the second synchronizer 2.

[0110] When the planetary reducer shifting mechanism is in low gear, power is input from the input gear 61 of the reduction mechanism 6, output from the output gear 63 to the input shaft 51, transmitted to the sun gear 52 of the planetary reducer 5 via the first synchronizer 1, output from the first planet carrier 53 of the planetary reducer to the second synchronizer 2, and then transmitted sequentially via the second synchronizer 2 to the first output shaft 54, the second planet carrier 71, the differential planetary gear 72 and the half-shaft gear 73, and then transmitted via the half-shaft gear 73 to the first half-shaft 74 and the second half-shaft 75 respectively.

[0111] This embodiment 1 also provides a vehicle, including the planetary reducer shifting mechanism provided in this embodiment 1.

[0112] Example 2:

[0113] This embodiment 2 also provides a control method for the planetary reducer shifting mechanism described in embodiment 1 above, including a first shifting control method for switching the vehicle from a high gear to a low gear while driving and a second shifting control method for switching the vehicle from the low gear to the high gear while driving.

[0114] The first shift control method includes the following steps:

[0115] Step 1: Synchronously move the first synchronizer 1 and the second synchronizer 2 through the shift fork unit, so that the second synchronizer 2 moves closer to the first synchronizer 1 while the first synchronizer 1 moves away from the second synchronizer 2.

[0116] Based on the movement of the synchronizer, the first synchronizer 1 is moved closer to the second synchronizer 2, which disconnects the connection between the first output shaft 54 ​​of the planetary reducer 5 and the input shaft 51 of the planetary reducer 5, so that the first synchronizer 1 is only connected to the input shaft 51 and the second synchronizer 2 is only connected to the first output shaft 54, and the vehicle shifts from high gear to neutral.

[0117] Step 2: After the vehicle is switched to neutral, the first synchronizer 1 and the second synchronizer 2 are continued to be moved synchronously through the shift fork unit, so that the second synchronizer 2 moves further towards the first synchronizer 1, while the first synchronizer 1 moves synchronously away from the second synchronizer 2.

[0118] Based on the further movement of the synchronizer, the side of the first synchronizer 1 away from the second synchronizer 2 connects the input shaft 51 and the sun gear 52, while the side of the second synchronizer close to the first synchronizer synchronously connects the first output shaft 54 ​​and the first planet carrier 53 of the planetary reducer 5. This allows the power transmitted by the input shaft 51 to be transmitted to the first output shaft 54 ​​after being reduced in speed and increased in torque by the sun gear 52 and the first planet carrier 53, and the vehicle shifts from neutral to low gear.

[0119] The second shift control method includes the following steps:

[0120] Step 1: Synchronously move the first synchronizer 1 and the second synchronizer 2 through the shift fork unit, so that the second synchronizer 2 moves away from the first synchronizer 1 while the first synchronizer 1 moves towards the second synchronizer 2.

[0121] Based on the movement of the synchronizer, the first synchronizer 1 is disconnected from the input shaft 51 and the sun gear 52 on the side away from the second synchronizer 2, while the second synchronizer 2 is disconnected from the first output shaft 54 ​​and the first planetary carrier 53 on the side close to the first synchronizer 1, so that the first synchronizer 1 is only connected to the input shaft 51 and the second synchronizer 2 is only connected to the first output shaft 54, and the vehicle shifts from low gear to neutral.

[0122] Step 2: After the vehicle is switched to neutral, the first synchronizer 1 and the second synchronizer 2 are continued to be moved synchronously through the shift fork unit, so that the second synchronizer 2 moves away from the first synchronizer 1 while the first synchronizer 1 moves towards the second synchronizer 2.

[0123] Based on the further movement of the synchronizer, the side of the first synchronizer 1 closer to the second synchronizer 2 connects the first output shaft 54 ​​and the input shaft 51, while the second synchronizer 2 is only connected to the first output shaft 54; the power transmitted by the input shaft 51 is directly transmitted to the first output shaft 54 ​​via the first synchronizer 1, and the vehicle switches from neutral to high gear. When the vehicle is in high gear, the sun gear 52 and the first planetary carrier 53 are both disconnected from the input shaft 51 and also from the first output shaft 54.

[0124] In this embodiment 2, the method of synchronously moving the first synchronizer 1 and the second synchronizer 2 through the shift fork unit includes:

[0125] The shift fork unit includes a first shift fork assembly 3 for shifting the first synchronizer 1 and a second shift fork assembly 4 for shifting the second synchronizer 2;

[0126] The second shift fork assembly 4 is fixedly connected to the first synchronizer 1 to constrain the second shift fork assembly 4 to move synchronously with the first synchronizer 1, so that while the first shift fork assembly 3 moves the first synchronizer 1, the second shift fork assembly 4 moves the second synchronizer 2 to move synchronously with the first synchronizer 1.

[0127] Alternatively, the first shift fork assembly 3 can be fixedly connected to the second synchronizer 2 to constrain the first shift fork assembly 3 and the second synchronizer 2 to move synchronously, so that while the second shift fork assembly 4 moves the second synchronizer 2, the first shift fork assembly 3 moves the first synchronizer 1 and the second synchronizer 2 synchronously.

[0128] The planetary reducer shifting mechanism and control method and the two-speed reduction gearbox provided by the present invention have at least the following technical effects or advantages:

[0129] 1. By controlling the first synchronizer 1 and the second synchronizer 2 to move synchronously back and forth along the central axis through the shift fork unit, the planetary reducer is controlled to shift gears. This achieves the function of shifting gears while ensuring that power is not transmitted to the planetary reducer at high speeds, thereby improving power transmission efficiency and reducing noise sources. This solves the problem in the existing planetary reducer shifting mechanism that cannot solve the problem of reduced transmission efficiency and increased operating noise caused by the planetary reducer idling at high speeds while achieving shifting gears while driving.

[0130] 2. By controlling the planetary reducer shifting through two synchronizers, it can be ensured that the movement of the vehicle's half-shaft in neutral can only be transmitted back to the first output shaft 54 ​​and the second synchronizer 2, and will not be transmitted to the sun gear 52, planet gears and the first planet carrier 53 of the planetary reducer 5, which further improves the power transmission efficiency and reduces energy loss.

[0131] 3. The second fork assembly 4 used to move the second synchronizer 2 is set to a fork assembly commonly used in the prior art. The first fork assembly 3 used to move the first synchronizer 1 is fixedly connected to the second synchronizer 2. This allows the first synchronizer 1 and the second synchronizer 2 to move synchronously back and forth along the central axis direction through the first fork assembly 3 and the second fork assembly 4.

[0132] 4. By setting the step portion 311, the third through hole and the retaining ring 33, the fork body 32 and the connecting piece 31 are detachably fixedly connected, which facilitates the assembly and disassembly of each component in the first fork assembly 3.

[0133] 5. By setting the shift fork body 32 as a plurality of arc-shaped parts 321 that are fixedly connected in sequence along the central axis, and the arc-shaped parts 321 are detachably fixedly connected in sequence, the installation and removal of the shift fork body 32 in the first shift fork groove 121 is facilitated.

[0134] 6. By ensuring that the number of arc-shaped parts 321 and connecting parts 31 are the same, and by providing a first connector 3211 and a second connector 3213 at both ends of the arc-shaped parts 321, the first mounting holes 3212 on the first connectors 3211 of the arc-shaped parts 321 are all matched with the second mounting holes 3214 on the second connectors 3213 of the adjacent arc-shaped parts 321. The stepped portion 311 passes through its corresponding first mounting hole 3212 and second mounting hole 3214. The retaining ring 33 cooperates with the stepped portion 311 to fix the corresponding first connectors 3211 and second connectors 3213, further facilitating the assembly and disassembly of the first shift fork assembly 3, and further facilitating the installation and disassembly of the shift fork body 32 in the first shift fork groove 121.

[0135] The above are merely specific application examples of the present invention and do not constitute any limitation on the scope of protection of the present invention. All technical solutions formed by equivalent transformation or equivalent substitution fall within the scope of protection of the present invention.

Claims

1. A planetary gear reducer shifting mechanism, characterized in that: It includes a shift fork unit and a first synchronizer and a second synchronizer arranged on the same central axis; The first synchronizer is a double-sided synchronizer, installed on the input shaft of the planetary reducer. The side of the first synchronizer away from the second synchronizer is used to connect the input shaft to the sun gear of the planetary reducer; the side of the first synchronizer closer to the second synchronizer is used to connect the input shaft to the first output shaft of the planetary reducer. The second synchronizer is a single-sided synchronizer, which is installed on the first output shaft. The side of the second synchronizer closer to the first synchronizer is used to connect the first output shaft to the first planet carrier of the planetary reducer. The shift fork unit is used to shift the first synchronizer and the second synchronizer, so that the first synchronizer and the second synchronizer move synchronously back and forth along the central axis, so as to connect the input shaft and the sun gear at the same time, and simultaneously connect the first output shaft and the first planetary carrier; or disconnect the connection between the input shaft and the sun gear, and simultaneously disconnect the connection between the first output shaft and the first planetary carrier, and then connect the input shaft and the first output shaft. The shift fork unit includes a first shift fork assembly for shifting the first synchronizer and a second shift fork assembly for shifting the second synchronizer, wherein the first shift fork assembly is fixedly connected to the second synchronizer or the second shift fork assembly is fixedly connected to the first synchronizer. The first shift fork assembly is fixedly connected to the second synchronizer; the first shift fork assembly includes a shift fork body and at least one connector, the connector is fixedly connected to the second synchronizer, and the shift fork body is fixedly connected to the connector; The first synchronizer includes a first gear sleeve and a first gear hub; the second synchronizer includes a second gear sleeve and a second gear hub. The inner circumferential surface of the first gear sleeve is splined with the outer circumferential surface of the first gear hub, and the inner circumferential surface of the second gear sleeve is splined with the outer circumferential surface of the second gear hub; the first gear hub is mounted on the input shaft, and the side of the first gear sleeve away from the second synchronizer is used to connect the input shaft to the sun gear of the planetary reducer; the side of the first gear sleeve close to the second synchronizer is used to connect the input shaft to the first output shaft. The second gear hub is mounted on the first output shaft, and the second gear sleeve is used to connect the first output shaft to the first planetary carrier on the side near the first synchronizer. A side plate is provided on the side of the second gear sleeve away from the first synchronizer. The connector is arranged parallel to the central axis. The first end of the connector is fixedly connected to the side plate. A first through hole is opened on the second gear hub to cooperate with the connector. The second end of the connector passes through the corresponding first through hole and is fixedly connected to the shift fork body. A second through hole is opened on the side plate, and the first output shaft passes through the second through hole through the side plate. The outer circumferential surface of the first tooth sleeve is provided with a first shift fork groove arranged in the circumferential direction. The shift fork body cooperates with the first shift fork groove so that when the second shift fork assembly moves the second tooth sleeve reciprocally along the central axis, the shift fork body synchronously drives the first tooth sleeve to reciprocate along the central axis.

2. The planetary reducer shifting mechanism according to claim 1, characterized in that: The number of the connectors is at least two, and each connector is evenly distributed circumferentially around the central axis; The shift fork body is annular and installed in the first shift fork groove. The inner side of the shift fork body is in clearance fit with the bottom of the first shift fork groove, so that the shift fork body can rotate relative to the first synchronizer around the central axis.

3. The planetary reducer shifting mechanism according to claim 2, characterized in that: The first shift fork assembly further includes a retaining ring. The second end of the connector is provided with a stepped portion. The shift fork body is provided with a third through hole that mates with the stepped portion. The stepped portion passes through the corresponding third through hole to restrict the shift fork body from sliding on the stepped portion toward the side plate. The stepped portion is provided with a retaining groove that extends circumferentially around the central axis. The retaining ring is sleeved on the outside of each connector and installed in the retaining groove. The inner side of the retaining ring mates with the bottom of the retaining groove, and the outer side of the retaining ring extends out of the retaining groove, so that the side of the retaining ring near the side plate contacts the side of the shift fork body away from the side plate to restrict the shift fork body from sliding away from the side plate on the stepped portion. The retaining ring fixes the shift fork body to the stepped portion.

4. The planetary reducer shifting mechanism according to claim 2, characterized in that: The shift fork body includes multiple arc-shaped components, which are sequentially and detachably fixedly connected along the circumference of the central axis to form a ring.

5. A two-speed gearbox, characterized in that, It includes a reduction mechanism, a differential, a planetary reducer, and a planetary reducer shifting mechanism as described in any one of claims 1-4; the first output shaft of the planetary reducer is connected to the second planetary carrier of the differential; The reduction mechanism includes an input gear, an idler gear, and an output gear. The input gear is mounted on the second output shaft of the electric vehicle's drive motor. The idler gear meshes with the input gear. The output gear is mounted on the input shaft and meshes with the idler gear.

6. A control method for a planetary reducer shifting mechanism as described in any one of claims 1-4, characterized in that: This includes a first shift control method for switching a vehicle from a high gear to a low gear while driving; The first shift control method includes the following steps: Step 1: Synchronously move the first synchronizer and the second synchronizer through the shift fork unit, so that the second synchronizer moves closer to the first synchronizer while the first synchronizer moves away from the second synchronizer. Based on the movement of the synchronizer, the first synchronizer is moved closer to the second synchronizer, disconnecting the first output shaft of the planetary reducer from the input shaft of the planetary reducer, so that the first synchronizer is connected only to the input shaft and the second synchronizer is connected only to the first output shaft, and the vehicle shifts from the high gear to neutral. Step 2: After the vehicle is switched to neutral, the first synchronizer and the second synchronizer are continued to be moved synchronously by the shift fork unit, so that the second synchronizer moves further toward the first synchronizer while the first synchronizer moves synchronously away from the second synchronizer. As the synchronizer moves further, the side of the first synchronizer away from the second synchronizer connects the input shaft to the sun gear, while the side of the second synchronizer close to the first synchronizer simultaneously connects the first output shaft to the first planet carrier of the planetary reducer. This allows the power transmitted by the input shaft to be transmitted to the first output shaft after being reduced in speed and increased in torque by the sun gear and the first planet carrier, and the vehicle switches from neutral to low gear.

7. The control method according to claim 6, characterized in that: The method of synchronously moving the first synchronizer and the second synchronizer through the shift fork unit includes: The shift fork unit includes a first shift fork assembly for shifting the first synchronizer and a second shift fork assembly for shifting the second synchronizer; The second shift fork assembly is fixedly connected to the first synchronizer to constrain the second shift fork assembly to move synchronously with the first synchronizer, so that while the first shift fork assembly moves the first synchronizer, the second shift fork assembly moves the second synchronizer synchronously with the first synchronizer. Alternatively, the first shift fork assembly can be fixedly connected to the second synchronizer to constrain the first shift fork assembly and the second synchronizer to move synchronously, so that while the second shift fork assembly moves the second synchronizer, the first shift fork assembly moves the first synchronizer and the second synchronizer synchronously.

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