Planetary reducer, power assembly and electric vehicle

Abstract

The invention provides a planetary reducer, a power assembly and an electric vehicle, and relates to the technical field of electric vehicles. The planetary reducer is in transmission connection with wheels of the electric vehicle through the first half shaft and the second half shaft. The planetary reducer comprises a first planet row, a second planet row, a first locking structure and a second locking structure. The first half shaft is used for receiving power transmitted by the first planet row, and the second half shaft is used for receiving power transmitted by the second planet row. The first planet row and the second planet row can make the first half shaft and the second half shaft rotate in a differential mode. The first locking structure is used for being fixedly connected with the first half shaft, and the second locking structure is used for being in transmission connection with the second half shaft. When the first locking structure and the second locking structure are coupled, the first locking structure and the second locking structure are used for being in transmission connection with the first half shaft and the second half shaft. By means of the first locking structure and the second locking structure, locking of the differential function of the planetary reducer can be achieved, and the risk that an electric vehicle cannot run on a bad road surface is reduced.

Description

Technical Field

[0001] This application relates to the field of electric vehicle technology, and in particular to a planetary reducer, powertrain, and electric vehicle. Background Technology

[0002] In a vehicle's powertrain, the reducer is used to lower the speed at which the drive motor outputs power, increasing the output torque. The differential is typically used in conjunction with the reducer; in scenarios such as cornering, the differential allows the left and right wheels to rotate at different speeds, contributing to smoother vehicle operation. However, when driving on rough surfaces, if one wheel slips, the differential may struggle to effectively transfer power to the wheel with greater traction, preventing the vehicle from getting out of trouble. Summary of the Invention

[0003] This application provides a planetary reducer, powertrain, and electric vehicle capable of locking differential function.

[0004] In a first aspect, embodiments of this application provide a planetary reducer, which is used to drive and connect the wheels of an electric vehicle via a first half-shaft and a second half-shaft, respectively. The planetary reducer includes multiple planetary gear sets, a first locking structure, and a second locking structure. Each planetary gear set includes a sun gear, planet gears, a planet carrier, and a ring gear. The planet gears are used to drive and connect the outer circumferential surface of the sun gear and the inner circumferential surface of the ring gear, and the planet carrier is used to drive and connect the planet gears.

[0005] The system comprises multiple planetary gear sets, including a first planetary gear set and a second planetary gear set. The ring gear of the first planetary gear set receives power, and its sun gear drives the sun gear of the second planetary gear set. A first half-shaft receives power transmitted from the planet carrier of the first planetary gear set, and a second half-shaft receives power transmitted from the ring gear of the second planetary gear set.

[0006] The first locking structure is used to fix the first half-shaft, and the second locking structure is used to drive the second half-shaft. When the first locking structure and the second locking structure are coupled, they drive the first half-shaft and the second half-shaft.

[0007] In this embodiment, the planetary reducer enables differential rotation of the first and second half-shafts. Specifically, the power received by the ring gear of the first planetary gear set has two transmission paths. In the first transmission path, the ring gear of the first planetary gear set transmits power to the first half-shaft through the planet gears and the planet carrier of the first planetary gear set. In the second transmission path, the ring gear of the first planetary gear set transmits power to the sun gear of the second planetary gear set through the planet gears and the sun gear of the first planetary gear set, and finally the second half-shaft is driven by the ring gear of the second planetary gear set. As can be seen from the first transmission path, the sun gear, planet gears, planet carrier, and ring gear of the first planetary gear set can all be in a rotating state. During vehicle turning, the wheels on both sides, which are respectively connected to the first and second half-shafts, experience different resistances. The planetary reducer can adjust the rotation state of the planet gears to distribute more power to the wheel with less resistance, thereby meeting the speed requirements of different wheels during vehicle turning.

[0008] In this embodiment, the planetary reducer integrates deceleration and differential functions. Compared to a solution using a separate differential in conjunction with the reducer, the planetary reducer in this embodiment has a higher degree of integration, which helps reduce the number of components and shorten the power transmission path. However, the differential function of the planetary reducer can cause vehicle driving difficulties in certain special scenarios. When a vehicle is driving on poor road surfaces such as ice, snow, or mud, the wheels are prone to slipping. Assuming one wheel slips while the other wheel has greater traction, because the slipping wheel experiences less resistance, the planetary reducer with differential function will still transmit more power to the slipping wheel, while the other wheel with greater traction receives insufficient power, ultimately causing the vehicle to be unable to get out of trouble.

[0009] To improve the planetary reducer's ability to handle wheel slippage, a locking structure can be used to lock the differential function. In existing solutions combining a reducer and a differential, the locking structure connects one half-shaft gear of the differential to the differential housing, allowing the differential housing to directly drive one half-shaft gear, limiting the speed difference between the two half-shaft gears, thus ensuring that both wheels rotate at the same speed. The locking structure can also lock the differential function by directly limiting the rotation of the planetary gears of the differential. Since the planetary reducer in this embodiment omits the differential structure, the locking structure cannot be directly connected to the half-shaft gears or the differential housing.

[0010] To achieve locking of the differential function of the planetary reducer, this embodiment, based on the characteristics of the planetary reducer, establishes a connection relationship between the first locking structure and the second locking structure and the first half-shaft and the second half-shaft, respectively. Taking the first locking structure as an example, since the planet gears of the first planetary gear set have a transmission relationship with the sun gear, the ring gear, and the planet carrier, connecting the first locking structure to the planet gears of the first planetary gear set would easily interfere with the normal operation of the first planetary gear set and increase the layout difficulty of the first planetary gear set and the first locking structure. The first half-shaft is driven by the output end of the first planetary gear set. This embodiment fixes the first locking structure to the first half-shaft, which allows direct adjustment of the speed of the first half-shaft without interfering with the power transmission of the first planetary gear set, thus reducing the difficulty of locking the differential function of the planetary reducer.

[0011] In this embodiment, when the first locking structure and the second locking structure are coupled, a transmission connection can be established between the first half-shaft and the second half-shaft. By adjusting the power distribution to the wheels on different sides, the driving performance of the electric vehicle on poor road surfaces is improved. Since the differential function of the planetary reducer only needs to be locked under certain special circumstances, when the electric vehicle is driving normally, the first locking structure and the second locking structure are in a decoupled state, and the planetary reducer can normally perform its differential function. To achieve the switching between the coupling and decoupling states between the first locking structure and the second locking structure, the second locking structure and the second half-shaft have a different connection relationship than the first locking structure and the first half-shaft, and the second locking structure can move relative to the second half-shaft.

[0012] In one embodiment, a first section of a first half-shaft along the axial direction of the planetary reducer passes through the sun gear of a first planetary gear set and extends into the sun gear of a second planetary gear set. The gap between the first section of the first half-shaft and the sun gear of the second planetary gear set is used to accommodate a first portion of a first locking structure. The outer circumferential surface of the first section of the first half-shaft is used to securely connect to the inner circumferential surface of the first portion of the first locking structure.

[0013] Since the embodiments of this application introduce a first locking structure and a second locking structure into a planetary reducer with differential function, if at least one of the first locking structure or the second locking structure can reuse the space occupied by the planetary reducer, the overall size of the planetary reducer can be avoided by excessively extending it, which helps to miniaturize the planetary reducer and powertrain design.

[0014] In this embodiment, by extending the first segment of the first half-shaft to the inner circumference of the sun gear of the second planetary gear set, the first half-shaft and the first locking structure can be fixedly connected using the space on the inner circumference of the sun gear of the second planetary gear set. This reduces the space occupied by the first locking structure in the planetary reducer, and the arrangement of the first locking structure and the second planetary gear set is more compact. Since the first locking structure also needs to be coupled to the second locking structure, the first part of the first locking structure can extend into the inner circumference of the sun gear of the second planetary gear set in the opposite direction to the first segment of the first half-shaft. The second locking structure can be connected to the part of the first locking structure that does not extend into the sun gear of the second planetary gear set, which is beneficial for balancing the connection relationship between the first locking structure and the first half-shaft and the second locking structure.

[0015] In one embodiment, the planet carrier of the first planetary gear set extends into the gap between the sun gear of the first planetary gear set and the first section of the first half-shaft, and the outer peripheral surface of the first section of the first half-shaft is used to fixably connect to the inner peripheral surface of the planet carrier of the first planetary gear set. The first part of the first locking structure is spaced apart from the planet carrier of the first planetary gear set.

[0016] In this configuration, the length of the sun gear extending into the second planetary gear set from the first section of the first half-shaft along the axial direction of the planetary reducer is greater than the length of the first part of the first locking structure.

[0017] In this embodiment, the first segment of the first half-shaft is distributed on the inner circumferential side of the sun gear of the first planetary set and the sun gear of the second planetary set. The planet carrier of the first planetary set extends into the inner circumferential side of the sun gear of the first planetary set, so that the outer circumferential surface of the first segment is also used to fix and connect the inner circumferential surface of the planet carrier of the first planetary set, which is beneficial to improving the utilization rate of the outer circumferential surface of the first segment.

[0018] In this embodiment, since the planet carrier of the first planetary gear set and the first part of the first locking structure are both located on the outer periphery of the first segment, the planet carrier of the first planetary gear set needs to avoid misalignment with the first locking structure. This limits the length of the first locking structure extending into the sun gear of the second planetary gear set. By extending the length of the first segment, this embodiment increases the contact area between the first segment and the first part of the first locking structure without affecting the extension of the planet carrier into the sun gear, thus improving the connection strength between the first segment and the first locking structure. When the first locking structure and the second locking structure are coupled, this embodiment adjusts the length of the first segment extending into the sun gear of the second planetary gear set, which helps to enhance the stability of the differential locking function of the first locking structure.

[0019] In one embodiment, the second segment of the first half-shaft is adjacent to the first segment of the first half-shaft, and the second segment of the first half-shaft is distributed on the side of the first planetary gear set opposite to the second planetary gear set. The outer diameter of the first segment of the first half-shaft is smaller than the outer diameter of the second segment of the first half-shaft along the radial direction of the planetary reducer.

[0020] In this embodiment, the outer peripheral surface of the first segment of the first half-shaft is used to fixably connect the first part of the first locking structure. By reducing the outer diameter of the first segment, the radial space between the first segment and the sun gear of the second planetary gear set can be increased, which helps to reduce the installation difficulty of the first part of the first locking structure and reduce the risk of interference between the first part of the first locking structure and the sun gear of the second planetary gear set. The reduced radial space occupied by the first segment avoids the need to increase the inner diameter of the sun gear of the second planetary gear set to fit the first segment and the first part of the first locking structure, which is beneficial for controlling the radial dimensions of the planetary reducer.

[0021] In this embodiment, the outer peripheral surface of the first segment of the first half-shaft is used to fixably connect the planet carrier of the first planetary gear set. By reducing the outer diameter of the first segment, the radial space between the first segment and the sun gear of the first planetary gear set can be increased, which helps to reduce the installation difficulty of the planet carrier of the first planetary gear set and reduces the risk of interference between the planet carrier and the sun gear of the first planetary gear set. The reduced radial space occupied by the first segment avoids the need to increase the inner diameter of the sun gear of the first planetary gear set to fit the first segment and the planet carrier of the first planetary gear set, which is beneficial for controlling the radial dimensions of the planetary reducer.

[0022] In this embodiment, the outer diameter of the second segment of the first half-shaft is larger than the outer diameter of the first segment. The second segment does not extend into the sun gear of the first planetary gear set or the sun gear of the second planetary gear set, thus avoiding interference between the second segment and the sun gear of the first planetary gear set or the sun gear of the second planetary gear set.

[0023] In one embodiment, the first half-shaft includes a through hole extending through a second section of the first half-shaft, the through hole being used to connect to the shaft cavity of the second section of the first half-shaft.

[0024] In this embodiment, based on the distribution characteristics of the first half-shaft in the planetary reducer, the first half-shaft, in addition to transmitting power, can also serve as a component of the lubrication system. Utilizing the first half-shaft to hold and transmit oil facilitates the flow of oil to the areas in the planetary reducer that require lubrication, thereby improving oil transmission efficiency.

[0025] To enable the first half-shaft to guide and distribute the oil, a through-hole needs to be formed in it. However, the through-hole reduces the structural strength of the first half-shaft, affecting the connection strength between it and the planetary carrier and locking structure of the first planetary gear set. Machining the through-hole in the first half-shaft requires material removal, disrupting the continuous cross-section and leading to localized stress concentration. Furthermore, the oil flow rate of the through-hole is related to its diameter; reducing the diameter to alleviate stress concentration would make it difficult for the through-hole to meet the lubrication requirements of the planetary reducer.

[0026] This embodiment of the application comprehensively considers the structural strength and oil flow efficiency of the first half-shaft, and places the through-hole in the second section of the first half-shaft, which has a relatively larger outer diameter. Since the outer diameter of the first section is smaller than that of the second section, the stiffness of the first section is less than that of the second section. This helps to adjust the stiffness change of the first half-shaft from the first section to the second section, avoiding abrupt changes in the stiffness between the first and second sections, thereby alleviating the stress concentration in the through-hole distributed in the second section. The first section has lower stiffness; placing the through-hole in the first section would further reduce its stiffness, impairing the connection strength between the first section and the first locking structure and the planetary carrier of the first planetary gear set. Placing the through-hole in the first section would also lead to excessive oil flow resistance.

[0027] In one embodiment, the ring gear of the second planetary gear set is used to drive the second half-shaft via an output disc, with the output disc distributed radially between the ring gear and the second half-shaft. A second locking structure is used to drive the second half-shaft via the output disc.

[0028] In this embodiment, the ring gear of the second planetary gear set surrounds the outer periphery of the sun gear and planet gears of the second planetary gear set. If the ring gear of the second planetary gear set were directly connected to the second half-shaft, the outer diameter of the second half-shaft would need to be increased, resulting in the second half-shaft occupying excessive space in the planetary reducer. To reduce the difficulty of transmitting power from the ring gear of the second planetary gear set to the second half-shaft, this embodiment utilizes an output disk to compensate for the radial distance between the ring gear of the second planetary gear set and the second half-shaft. The ring gear of the second planetary gear set can be fixedly connected to the second half-shaft via the output disk.

[0029] In this embodiment, the second locking structure can reuse the output disk, reducing the number of structural components. The output disk is driven by the gear ring of the second planetary gear set, and the second locking structure can receive the power transmitted by the gear ring of the second planetary gear set through the output disk. The output disk is driven by the second half-shaft, and the second locking structure can establish the connection between the first and second half-shafts through the output disk. Since the second locking structure needs to move, drivingly connecting the second locking structure to the output disk also helps reduce the machining of the second half-shaft and facilitates the second locking structure to perform its locking differential function.

[0030] In one embodiment, a second portion of the first locking structure extends from the sun gear of the second planetary gear set. The output disk includes a recess along the axial direction of the planetary reducer, recessed away from the second planetary gear set. The recess accommodates the second portion of the first locking structure and the second locking structure, with a second half-shaft extending into the recess through the bottom of the recess. The second locking structure surrounds the outer periphery of the second half-shaft.

[0031] In this embodiment, the second part of the first locking structure extends from the sun gear of the second planetary gear set toward the second locking structure, and the second part of the first locking structure can be used to couple the second locking structure. Since the output disk needs to be connected to the second locking structure for transmission, the layout of the output disk, the second locking structure, and the first locking structure in the planetary reducer can be optimized by improving the structure of the output disk. Specifically, the output disk includes a groove, which faces away from the recess of the second planetary gear set. By arranging the second part of the first locking structure and the second locking structure in the groove of the output disk, the first locking structure and the second locking structure are arranged compactly, which helps to reduce the difficulty of coupling. The compact arrangement of the second locking structure and the output disk helps to improve the transmission efficiency between the output disk and the second locking structure. The second half-shaft extends into the groove through the bottom of the groove, and the projection of the second half-shaft along the radial direction of the planetary reducer overlaps with the projection of the second locking structure, reducing the axial space occupied by the second half-shaft and the second locking structure. The output disk integrates the first locking structure, the second locking structure, and the second half-shaft into the groove, which helps to achieve a compact layout of the first locking structure, the second locking structure, and the second half-shaft, and reduces the volume of the planetary reducer.

[0032] In one embodiment, the inner diameter of the radial groove along the planetary reducer is smaller than the outer diameter of the gear ring of the second planetary gear set.

[0033] In this embodiment, the output disk integrates a portion of the second locking structure and a portion of the second half-shaft within a groove, facilitating the transmission connection between the output disk and the first locking structure and the second half-shaft, respectively, to achieve power transmission. The output disk also integrates a portion of the first locking structure and a portion of the second locking structure within the groove, reducing the difficulty of coupling the second locking structure with the first locking structure.

[0034] In this embodiment, the groove needs to provide a accommodating area for the first locking structure, the second locking structure, and the second half-shaft, but it is also necessary to avoid the problem of the groove occupying too much space. This embodiment reduces the radial space occupied by the groove by adjusting its inner diameter, which helps to reduce the layout difficulty of other components in the planetary reducer.

[0035] In one embodiment, the first locking structure includes a first opening and a second opening, with the first opening facing the first planetary gearbox along the axial direction of the planetary reducer, and the first opening being used to fix the first half-shaft of the connecting portion.

[0036] The second opening along the axial direction of the planetary reducer faces the second locking structure. The inner diameter of the second opening is larger than the inner diameter of the first opening. The second opening is used to accommodate part of the second half-shaft.

[0037] This application embodiment introduces a first locking structure and a second locking structure into a planetary reducer with differential function. Both structures occupy a portion of the planetary reducer's axial space. To control the axial dimensions of the planetary reducer, a second opening in the first locking structure facing the second locking structure is used to accommodate a portion of the second half-shaft. This application embodiment adjusts the layout of the second half-shaft within the planetary reducer through this second opening. Instead of being stacked axially with the first and second locking structures, the second half-shaft reuses the space on the inner periphery of the first and second locking structures, resulting in a more compact overall arrangement of the planetary reducer. The inner diameter of the second opening is larger than that of the first opening, which avoids interference between the first locking structure and the second half-shaft while allowing the second opening to accommodate the second half-shaft, thus improving the stability of power transmission.

[0038] In one embodiment, the second locking structure includes a protrusion extending beyond the surface of the second locking structure toward the output disk. The output disk includes a mounting hole for actuating the protrusion through the hole wall to drive the connection of the second locking structure.

[0039] Among them, the length of the circumferential mounting hole of the planetary reducer is greater than the length of the protrusion, and the length of the radial mounting hole of the planetary reducer is greater than the length of the protrusion.

[0040] In this embodiment, the second locking structure needs to transmit power to the output disk, and it also needs to move relative to the output disk. To accommodate both of these requirements, the mounting hole of the output disk is used to accommodate the protrusion of the second locking structure. When the wall of the mounting hole abuts against the protrusion, the output disk can be driven to connect with the second locking structure. To reduce the resistance and wear experienced by the second locking structure during its movement relative to the output disk, the circumferential length of the mounting hole is greater than the circumferential length of the protrusion, and the radial length of the mounting hole is greater than the radial length of the protrusion.

[0041] In one embodiment, the second locking structure includes transmission teeth distributed on the end face of the second locking structure facing the first locking structure along the axial direction of the planetary reducer. The second locking structure is used to drively connect to the first locking structure via the transmission teeth.

[0042] Among them, the pressure angle of the protrusion is greater than the pressure angle of the transmission tooth.

[0043] In this embodiment, the second locking structure is connected to the first locking structure via transmission teeth, and the second locking structure is connected to the output disk via a protrusion. When the second locking structure is coupled to the first locking structure, the pressure angle between the transmission teeth and the protrusion affects the stability of the connection between the two structures. Specifically, the output disk transmits power to the second locking structure, the mounting hole abuts against the protrusion, generating a first axial force, which pushes the second locking structure closer to the first locking structure. The transmission teeth of the second locking structure mesh with the first locking structure, generating a second axial force, which is opposite in direction to the first axial force. To prevent premature decoupling between the second and first locking structures, the first axial force must be greater than the second axial force. To improve the stability of the connection between the first and second locking structures, this embodiment adjusts the pressure angle of the protrusion to be greater than the pressure angle of the transmission teeth.

[0044] In one embodiment, the planetary reducer includes an actuator for receiving electrical energy to drive a second locking structure coupled to a first locking structure. The planetary reducer housing includes a receiving groove with the groove opening facing the first planetary gear set along the axial direction of the planetary reducer, and a second half-shaft extending into the receiving groove through the bottom of the groove.

[0045] The distance between the radial wall of the receiving groove of the planetary reducer and the second locking structure is less than the distance between the receiving groove wall and the second half-shaft. The bottom of the receiving groove is spaced apart from the first planetary set and the second planetary set. The space between the receiving groove wall and the second locking structure is used to accommodate the actuator, which is fixedly connected to the receiving groove wall and the bottom.

[0046] In this embodiment, the actuator provides power to the second locking structure, enabling the second locking structure to move towards the first locking structure and complete the differential locking function. Since the receiving slot does not rotate, fixing the actuator to the receiving slot avoids negative impacts on the transmission efficiency of the planetary reducer compared to fixing the actuator to the moving parts. Furthermore, the installation of the actuator involves wiring harness arrangement. If the actuator is too close to the moving parts in the planetary reducer, interference problems may occur, interfering with the normal operation of multiple planetary sets, the first locking structure, and the second locking structure. This embodiment utilizes the radial space between the wall of the receiving slot and the second locking structure to accommodate the actuator, and uses the walls and bottom of the receiving slot to fix the actuator. By adjusting the layout of the actuator in the receiving slot, clearance space can be provided between the actuator and the first and second planetary sets, facilitating the wiring harness arrangement of the actuator.

[0047] In one embodiment, the actuator is an electromagnetic actuator, which includes an electromagnetic coil, and the receiving groove is made of a non-magnetic metal.

[0048] In this embodiment, after the actuator is energized, the electromagnetic coil in the actuator generates a magnetic field. To ensure the actuator functions properly, the receiving groove a used to fix the actuator is made of a non-magnetic metal, which helps reduce the risk of magnetic leakage.

[0049] Secondly, embodiments of this application provide a powertrain including a drive motor and a planetary reducer as described in any embodiment of the first aspect. A first half-shaft passes through the motor shaft of the drive motor. The planetary reducer further includes a third planetary set, the sun gear of which is distributed on the outer circumferential surface of the motor shaft. The planet carrier of the third planetary set is used for transmission connection to the ring gear of the first planetary set.

[0050] In the embodiments of this application, the planetary reducer in any embodiment of the first aspect is applied to the powertrain. Since the differential function of the planetary reducer can be locked by the first locking structure and the second locking structure, the powertrain can adjust the power distribution between the first half-shaft and the second half-shaft according to driving requirements, which is beneficial to improving the reliability of the powertrain.

[0051] In this embodiment, the third planetary gear set receives power from the drive motor via the motor shaft. Integrating the third sun gear into the motor shaft improves the structural strength of the powertrain and the stability of power transmission.

[0052] In this embodiment, the first half-shaft passes through the motor shaft, reusing the installation space of the powertrain occupied by the motor shaft, reducing the volume of the powertrain, and also reducing the difficulty of arranging other components located outside the motor shaft in the powertrain.

[0053] Thirdly, embodiments of this application provide an electric vehicle, which includes a power battery and a powertrain as described in the second aspect, the powertrain being used to receive power from the power battery and to drive the wheels of the electric vehicle.

[0054] In this embodiment of the application, applying the powertrain of the second aspect to electric vehicles is beneficial to improving the ability of electric vehicles to cope with poor road conditions and reducing the risk of electric vehicles being unable to get out of trouble.

[0055] In one embodiment, the electric vehicle includes a power battery and a planetary gearbox as described in any embodiment of the first aspect, the planetary gearbox being used to drive the wheels of the electric vehicle.

[0056] In the embodiments of this application, applying the planetary reducer in any embodiment of the first aspect to an electric vehicle is beneficial to improving the electric vehicle's ability to cope with poor road conditions and reducing the risk of the electric vehicle being unable to get out of trouble. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments of this application will be described below.

[0058] Figure 1 This is a schematic diagram of an electric vehicle provided in an embodiment of this application; Figure 2 This is a schematic diagram of the powertrain and wheels provided in an embodiment of this application; Figure 3 This is a schematic diagram of the powertrain provided in an embodiment of this application; Figure 4 This is a cross-sectional view of a partial structure of the powertrain provided in an embodiment of this application; Figure 5 This is a cross-sectional view of a partial structure of the powertrain provided in an embodiment of this application; Figure 6 This is an exploded view of the powertrain provided in the embodiments of this application; Figure 7 This is an exploded view of the powertrain provided in the embodiments of this application; Figure 8 This is a schematic diagram of the pressure angle provided in an embodiment of this application; Figure 9 This is a cross-sectional view of a partial structure of the powertrain provided in an embodiment of this application; Figure 10 This is a schematic diagram of the powertrain provided in an embodiment of this application. Detailed Implementation

[0059] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0060] For ease of understanding, the relevant technical terms involved in the embodiments of this application will be explained and described below.

[0061] Parallelism: The parallelism defined in the embodiments of this application is not limited to absolute parallelism. This definition of parallelism can be understood as basic parallelism, allowing for situations where the parallelism is not absolute due to factors such as assembly tolerance, design tolerance, and structural flatness.

[0062] This application provides a planetary reducer for driving and connecting different wheels of an electric vehicle via a first half-shaft and a second half-shaft. The planetary reducer includes multiple planetary gear sets, a first locking structure, and a second locking structure. The multiple planetary gear sets are arranged along the axial direction of the reducer. Each planetary gear set includes a sun gear, planet gears, a planet carrier, and a ring gear. The planet gears drive and connect the outer circumferential surface of the sun gear and the inner circumferential surface of the ring gear, and the planet carrier drives and connects the planet gears.

[0063] The system comprises multiple planetary gear sets, including a first planetary gear set and a second planetary gear set. The ring gear of the first planetary gear set receives power, and its sun gear drives the sun gear of the second planetary gear set. A first half-shaft receives power from the planet carrier of the first planetary gear set, and a second half-shaft receives power from the ring gear of the second planetary gear set. The first and second planetary gear sets allow for differential rotation of the first and second half-shafts, providing both speed reduction and differential functions.

[0064] The first locking structure is used to fix the first half-shaft, and the second locking structure is used to drive the second half-shaft. When the first locking structure and the second locking structure are coupled, they drive the first half-shaft and the second half-shaft.

[0065] This application embodiment, by coupling the first locking structure and the second locking structure, can lock the differential function of the planetary reducer, reducing the risk that electric vehicles cannot drive on poor road surfaces.

[0066] The planetary reducer provided in this application embodiment can be applied to powertrains and electric vehicles, helping to improve the reliability and safety of powertrains and electric vehicles.

[0067] Please see Figure 1 , Figure 1 This is a schematic diagram of the electric vehicle 1 provided in an embodiment of this application.

[0068] The electric vehicle 1 in this embodiment includes a powertrain 10 and a power battery 20. In this embodiment, the electric vehicle 1 refers to a wheeled device driven or towed by a power unit. The power battery 20 supplies power to the powertrain 10; the power battery 20 can also be called a battery pack. The powertrain 10 is the power source of the electric vehicle 1 and drives the wheels 30 of the electric vehicle 1. In one embodiment, the electric vehicle 1 further includes a frame 40, which is used to mount the powertrain 10 and the power battery 20. The frame 40 is the structural skeleton of the electric vehicle 1 and can withstand the loads from the internal and external environments of the electric vehicle 1. It should be noted that... Figure 1 The electric vehicle 1 is shown schematically only, including the powertrain 10, power battery 20, wheels 30 and frame 40, and does not represent the specific structure, size and positional relationship of the powertrain 10, power battery 20, wheels 30 and frame 40.

[0069] Please see Figure 2 , Figure 2 This is a schematic diagram of the powertrain 10 and wheels 30 provided in the embodiments of this application.

[0070] The powertrain 10 of this application embodiment includes a drive motor 400 and a planetary reducer 100. In one embodiment, the powertrain 10 further includes a motor controller 500. It should be noted that... Figure 2 This does not represent the actual structure, size, and positional relationship of the motor controller 500, drive motor 400, planetary reducer 100, and wheel 30.

[0071] The power battery supplies power to the drive motor 400 via the motor controller 500. The motor controller 500 converts the direct current supplied by the power battery into alternating current and delivers the alternating current to the drive motor 400. In one embodiment, the motor controller 500 is also used to control at least one of the drive motor 400 or the planetary reducer 100.

[0072] The drive motor 400 converts electrical energy into mechanical energy to generate driving torque. In one embodiment, the drive motor 400 includes a motor shaft 410, a motor rotor, and a motor stator. The motor shaft 410 is used to fixably connect to the inner circumferential surface of the motor rotor. The windings of the motor stator are used to receive alternating current transmitted by the motor controller 500. After receiving the alternating current provided by the motor controller 500, the motor stator drives the motor rotor to rotate, thereby driving the motor shaft 410 to rotate.

[0073] Planetary reducer 100 is used to reduce the speed of the power output by drive motor 400 and increase torque. Depending on the different architectures used, reducers can be divided into planetary reducers 100 and parallel shaft reducers. Planetary reducer 100 adopts a coaxial arrangement of input and output ends, and compared to parallel shaft reducers, it has the advantages of a compact structure and smaller radial dimensions.

[0074] In one embodiment, the planetary reducer 100 has a differential function. When the electric vehicle is turning or traveling on uneven surfaces, the planetary reducer 100 with differential function can cause the wheels on different sides to rotate at different speeds.

[0075] In one embodiment, the powertrain 10 includes an adapter half-shaft, a drive motor 400 for driving the adapter half-shaft via a planetary reducer 100, and the adapter half-shaft for driving wheels via a transmission half-shaft 600. In one embodiment, the adapter half-shaft and the transmission half-shaft 600 are fixedly connected. Exemplarily, the adapter half-shaft and the transmission half-shaft 600 are fixedly connected via a spline fit. In one embodiment, the adapter half-shaft includes a first half-shaft 200 and a second half-shaft 300, which are used to drive different wheels 30 via different transmission half-shafts 600. It should be noted that... Figure 2 This does not represent the actual structure, dimensions, and positional relationship of the first half-shaft 200, the second half-shaft 300, and the transmission half-shaft 600.

[0076] In scenarios where electric vehicles become stuck due to wheel slippage, it is necessary to adjust the power distribution between the wheels on different sides. This application's embodiment utilizes a locking structure to lock the differential function of the planetary reducer, limiting the speed difference between the wheels on different sides. This improves the electric vehicle's adaptability to poor road conditions and enhances its safety performance.

[0077] The planetary reducer 100 provided in the embodiments of this application is described in detail below.

[0078] Please see Figure 3 and Figure 4 , Figure 3 This is a schematic diagram of the powertrain 10 provided in an embodiment of this application. Figure 4 This is a cross-sectional view of a partial structure of the powertrain 10 provided in the embodiments of this application.

[0079] The planetary reducer 100 is used to drive the wheels 30 of the electric vehicle 1 via the first half-shaft 200 and the second half-shaft 300 respectively. The planetary reducer 100 includes multiple planetary gear sets 110, a first locking structure 120 and a second locking structure 130. Each planetary gear set 110 includes a sun gear 111, planet gears 112, a planet carrier 113 and a ring gear 114. The planet gears 112 are used to drive the outer circumferential surface of the sun gear 111 and the inner circumferential surface of the ring gear 114, and the planet carrier 113 is used to drive the planet gears 112.

[0080] The multiple planetary gear sets 110 include a first planetary gear set 110a and a second planetary gear set 110b. For ease of description, the sun gear 111, planet gear 112, planet carrier 113, and ring gear 114 of the first planetary gear set 110a are respectively referred to as the first sun gear 111a, the first planet gear 112a, the first planet carrier 113a, and the first ring gear 114a. The sun gear 111, planet gear 112, planet carrier 113, and ring gear 114 of the second planetary gear set 110b are respectively referred to as the second sun gear 111b, the second planet gear 112b, the second planet carrier 113b, and the second ring gear 114b.

[0081] The first ring gear 114a receives power, and the first sun gear 111a is used to drive the second sun gear 111b. The first half-shaft 200 receives power transmitted from the first planetary carrier 113a, and the second half-shaft 300 receives power transmitted from the second ring gear 114b. A first locking structure 120 is used to fix the first half-shaft 200, and a second locking structure 130 is used to drive the second half-shaft 300. When the first locking structure 120 and the second locking structure 130 are coupled, they drive the first half-shaft 200 and the second half-shaft 300.

[0082] In this embodiment, the planetary reducer 100 enables the first half-shaft 200 and the second half-shaft 300 to rotate differentially. Specifically, the power received by the first ring gear 114a has two transmission paths. In the first transmission path, the first ring gear 114a transmits power to the first half-shaft 200 through the first planetary gear 112a and the first planetary carrier 113a. In the second transmission path, the first ring gear 114a transmits power to the second sun gear 111b through the first planetary gear 112a and the first sun gear 111a, and the second half-shaft 300 is ultimately driven by the second ring gear 114b. As can be seen from the first transmission path, in the first planetary gear set 110a, the first sun gear 111a, the first planetary gear 112a, the first planetary carrier 113a, and the first ring gear 114a can all be in a rotating state. During vehicle turning, the two wheels connected to the first half-shaft 200 and the second half-shaft 300 respectively experience different resistances. The planetary reducer 100 can adjust the rotation state of the planetary gear 112 to distribute more power to the wheel with less resistance, so as to meet the vehicle's turning requirements for the speed of the wheels on different sides.

[0083] In this embodiment, the planetary reducer 100 integrates deceleration and differential functions. Compared to a solution that uses a separate differential in conjunction with the reducer, the planetary reducer 100 in this embodiment has a higher degree of integration, which helps reduce the number of components and shorten the power transmission path. However, the differential function of the planetary reducer 100 can cause vehicle driving difficulties in certain special scenarios. When a vehicle is driving on poor road surfaces such as ice, snow, or mud, the wheels are prone to slipping. Assuming one wheel slips while the other wheel has greater traction, because the slipping wheel experiences less resistance, the planetary reducer 100 with differential function will still transmit more power to the slipping wheel, while the other wheel with greater traction receives insufficient power, ultimately causing the vehicle to be unable to get out of trouble.

[0084] To improve the ability of electric vehicles to cope with wheel slippage, a locking structure can be used to lock the differential function. In existing solutions that combine a reducer and a differential, the locking structure connects one half-shaft gear of the differential to the differential housing, allowing the differential housing to directly drive one half-shaft gear, limiting the speed difference between the two half-shaft gears, thereby ensuring that both wheels rotate at the same speed. The locking structure can also lock the differential function by directly limiting the rotation of the planetary gears of the differential. Since the planetary reducer 100 of this application embodiment omits the differential structure, the locking structure cannot be directly connected to the half-shaft gears or the differential housing of the differential.

[0085] To achieve locking of the differential function of the planetary reducer 100, this embodiment, based on the characteristics of the planetary reducer 100, establishes a connection relationship between the first locking structure 120 and the second locking structure 130 and the first half-shaft 200 and the second half-shaft 300, respectively. Taking the first locking structure 120 as an example, since the first planetary gear 112a has a transmission relationship with the first sun gear 111a, the first ring gear 114a, and the first planet carrier 113a, connecting the first locking structure 120 to the first planetary gear 112a would easily interfere with the normal operation of the first planetary gear set 110a and increase the layout difficulty of the first planetary gear set 110a and the first locking structure 120. The first half-shaft 200 is connected to the output end of the first planetary gear set 110a. This embodiment fixes the first locking structure 120 to the first half-shaft 200, which allows direct adjustment of the speed of the first half-shaft 200 without interfering with the power transmission of the first planetary gear set 110a, thus reducing the difficulty of locking the differential function of the planetary reducer 100.

[0086] In this embodiment, when the first locking structure 120 and the second locking structure 130 are coupled, a transmission connection can be established between the first half-shaft 200 and the second half-shaft 300. By adjusting the power distribution to the wheels on different sides, the driving performance of the electric vehicle on poor road surfaces is improved. Since the differential function of the planetary reducer 100 only needs to be locked under certain special circumstances, when the electric vehicle is driving normally, the first locking structure 120 and the second locking structure 130 are in a decoupled state, and the planetary reducer 100 can normally perform the differential function. To achieve the switching between the coupling and decoupling states between the first locking structure 120 and the second locking structure 130, the second locking structure 130 and the second half-shaft 300 have a different connection relationship than that between the first locking structure 120 and the first half-shaft 200. The second locking structure 130 can move relative to the second half-shaft 300.

[0087] In one embodiment, the first planetary gear set 110a and the second planetary gear set 110b are arranged along the axial direction O of the planetary reducer 100.

[0088] In one embodiment, the axial direction O of the planetary reducer 100 is parallel to the axial direction of the first half-shaft 200.

[0089] Please refer to the following: Figure 4 and Figure 5 , Figure 5 This is a cross-sectional view of a partial structure of the powertrain 10 provided in the embodiments of this application.

[0090] In one embodiment, the first half-shaft 200 passes through the motor shaft 410 of the drive motor 400. The planetary reducer 100 also includes a third planetary set 110c. For ease of description, the sun gear 111, planet gears 112, planet carrier 113, and ring gear 114 of the third planetary set 110c are respectively referred to as the third sun gear 111c, the third planet gear 112c, the third planet carrier 113c, and the third ring gear 114c. The third sun gear 111c is distributed on the outer circumferential surface of the motor shaft 410, and the third planet carrier 113c is used for transmission connection to the first ring gear 114a. In one embodiment, the axial direction O of the planetary reducer 100 is parallel to the axial direction of the drive motor 400.

[0091] In this embodiment, the third planetary gear set 110c receives power from the drive motor 400 via the motor shaft 410. Integrating the third sun gear 111c into the motor shaft 410 improves the structural strength and power transmission stability of the third planetary gear set 110c, thereby enhancing the vehicle's NVH performance. In one embodiment, the third planetary gear set 110c, the first planetary gear set 110a, and the second planetary gear set 110b are arranged sequentially along the axial direction O of the planetary reducer 100.

[0092] In this embodiment, the third planetary gear set 110c is combined with the first planetary gear set 110a and the second planetary gear set 110b. The third planetary gear set 110c can achieve the first stage of speed reduction for the power output from the drive motor 400, which is beneficial to enhancing the speed reduction and torque increase effect of the planetary reducer 100. The third planetary carrier 113c is connected to the first ring gear 114a for transmission, so that the planetary reducer 100 can use the first planetary carrier 113a and the first sun gear 111a as the output of the first planetary gear set 110a, so that the first planetary gear set 110a can transmit power to the first half-shaft 200 and the second planetary gear set 110b respectively.

[0093] In this embodiment, the first half-shaft 200 passes through the motor shaft 410, reusing the installation space of the powertrain 10 occupied by the motor shaft 410, reducing the volume of the powertrain 10, and also reducing the difficulty of arranging other components located outside the motor shaft 410 in the powertrain 10.

[0094] Please continue reading. Figure 4 and Figure 5 In one embodiment, along the axial direction O of the planetary reducer 100, a first segment 210 of a first half-shaft 200 passes through a first sun gear 111a and extends into a second sun gear 111b. The gap between the first segment 210 of the first half-shaft 200 and the second sun gear 111b is used to accommodate a first portion 121 of a first locking structure 120. The outer peripheral surface of the first segment 210 of the first half-shaft 200 is used to securely connect to the inner peripheral surface of the first portion 121 of the first locking structure 120.

[0095] Since the embodiments of this application introduce a first locking structure 120 and a second locking structure 130 into a planetary reducer 100 with differential function, if at least one of the first locking structure 120 or the second locking structure 130 can reuse the space occupied by the planetary reducer 100, the overall size of the planetary reducer 100 can be avoided by excessively extending it, which helps to miniaturize the planetary reducer 100 and the powertrain 10.

[0096] In this embodiment, by extending the first segment 210 of the first half-shaft 200 to the inner circumference of the second sun gear 111b, the first half-shaft 200 and the first locking structure 120 are conveniently fixedly connected using the space on the inner circumference of the second sun gear 111b, reducing the space occupied by the first locking structure 120 in the planetary reducer 100, and making the arrangement of the first locking structure 120 and the second planetary gear set 110b more compact. Since the first locking structure 120 also needs to be coupled with the second locking structure 130, the first part 121 of the first locking structure 120 can extend into the inner circumference of the second sun gear 111b in the opposite direction to the first segment 210 of the first half-shaft 200, and the second locking structure 130 can be connected to the part of the first locking structure 120 that does not extend into the second sun gear 111b, which is beneficial to take into account the connection relationship between the first locking structure 120 and the first half-shaft 200 and the second locking structure 130.

[0097] Please continue reading. Figure 4 and Figure 5 In one embodiment, the first planetary carrier 113a extends into the gap between the first sun gear 111a and the first segment 210 of the first half-shaft 200, and the outer peripheral surface of the first segment 210 of the first half-shaft 200 is used to fixably connect to the inner peripheral surface of the first planetary carrier 113a. The first portion 121 of the first locking structure 120 is spaced apart from the first planetary carrier 113a. The length of the first segment 210 of the first half-shaft 200 extending into the second sun gear 111b along the axial direction O of the planetary reducer 100 is greater than the length of the first portion 121 of the first locking structure 120.

[0098] In this embodiment, the first segment 210 of the first half-shaft 200 is distributed on the inner circumferential side of the first sun gear 111a and the second sun gear 111b. The first planetary carrier 113a extends into the inner circumferential side of the first sun gear 111a, so that the outer circumferential surface of the first segment 210 is also used to fix the inner circumferential surface of the first planetary carrier 113a, which is beneficial to improving the utilization rate of the outer circumferential surface of the first segment 210. In one embodiment, the first segment 210 and the first planetary carrier 113a, and the first segment 210 and the first locking structure 120 can adopt the same fixing method. Exemplarily, the outer circumferential surface of the first segment 210 includes a spline, and the first segment 210 is used to fix the first planetary carrier 113a and the first locking structure 120 through the spline, which is beneficial to reducing the machining difficulty of the first half-shaft 200.

[0099] In this embodiment, since the first planetary carrier 113a and the first portion 121 of the first locking structure 120 are both distributed on the outer periphery of the first segment 210, the first planetary carrier 113a needs to avoid interfering with the first locking structure 120, thus limiting the length of the first locking structure 120 extending into the second sun gear 111b. This embodiment, by extending the length of the first segment 210, increases the contact area between the first segment 210 and the first portion 121 of the first locking structure 120 without affecting the extension of the first planetary carrier 113a into the first sun gear 111a, thereby improving the connection strength between the first segment 210 and the first locking structure 120. When the first locking structure 120 and the second locking structure 130 are coupled, this embodiment adjusts the length of the first segment 210 extending into the second sun gear 111b, which helps to enhance the stability of the locking differential function of the first locking structure 120.

[0100] Please continue reading. Figure 4 and Figure 5 In one embodiment, the second segment 220 of the first half-shaft 200 is adjacent to the first segment 210 of the first half-shaft 200, and the second segment 220 of the first half-shaft 200 is distributed on the side of the first planetary gear set 110a away from the second planetary gear set 110b. The outer diameter of the first segment 210 of the first half-shaft 200 along the radial direction R of the planetary reducer 100 is smaller than the outer diameter of the second segment 220 of the first half-shaft 200.

[0101] In this embodiment, the outer peripheral surface of the first segment 210 of the first half-shaft 200 is used to fixably connect the first part 121 of the first locking structure 120. By reducing the outer diameter of the first segment 210, the radial space between the first segment 210 and the second sun gear 111b can be increased, which helps to reduce the installation difficulty of the first part 121 of the first locking structure 120 and reduce the risk of interference between the first part 121 of the first locking structure 120 and the second sun gear 111b. The reduced radial space occupied by the first segment 210 avoids the need to increase the inner diameter of the second sun gear 111b to fit the first segment 210 and the first part 121 of the first locking structure 120, which is beneficial for controlling the radial R dimension of the planetary reducer 100.

[0102] In this embodiment, the outer peripheral surface of the first segment 210 of the first half-shaft 200 is used to fixably connect the first planetary carrier 113a. By reducing the outer diameter of the first segment 210, the radial space between the first segment 210 and the first sun gear 111a can be increased, which helps to reduce the installation difficulty of the first planetary carrier 113a and reduce the risk of interference between the first planetary carrier 113a and the first sun gear 111a. The reduced radial space occupied by the first segment 210 avoids the need to increase the inner diameter of the first sun gear 111a to fit the first segment 210 and the first planetary carrier 113a, which is beneficial for controlling the radial dimensions of the planetary reducer 100.

[0103] In this embodiment, the outer diameter of the second segment 220 of the first half-shaft 200 is larger than the outer diameter of the first segment 210. The second segment 220 does not extend into the first sun gear 111a and the second sun gear 111b, thus avoiding interference between the second segment 220 and the first sun gear 111a and the second sun gear 111b.

[0104] Please continue reading. Figure 4 and Figure 5 In one embodiment, the first half-shaft 200 includes a through hole 230 that extends through the second segment 220 of the first half-shaft 200 and is used to connect the shaft cavity of the second segment 220 of the first half-shaft 200.

[0105] In this embodiment, based on the distribution characteristics of the first half-shaft 200 in the planetary reducer 100, the first half-shaft 200, in addition to transmitting power, can also serve as a component of the lubrication system. The first half-shaft 200 is used to contain and transmit oil, facilitating the flow of oil to the areas in the planetary reducer 100 that require lubrication, thereby improving oil transmission efficiency.

[0106] To enable the first half-shaft 200 to guide and distribute the oil, a through-hole 230 needs to be formed in the first half-shaft 200. However, the through-hole 230 reduces the structural strength of the first half-shaft 200 and affects the connection strength between the first half-shaft 200 and the first planetary carrier 113a and the first locking structure 120. Machining the through-hole 230 in the first half-shaft 200 requires the removal of some material, which disrupts the continuous cross-section of the first half-shaft 200 and leads to localized stress concentration. Furthermore, the oil flow rate of the through-hole 230 is related to its diameter. If the stress concentration is alleviated by reducing the diameter of the through-hole 230, it will be difficult for the through-hole 230 to meet the lubrication requirements of the planetary reducer 100.

[0107] This embodiment of the application comprehensively considers the structural strength and oil flow efficiency of the first half-shaft 200, and positions the through hole 230 in the second segment 220 of the first half-shaft 200, which has a relatively larger outer diameter. Since the outer diameter of the first segment 210 is smaller than that of the second segment 220, the stiffness of the first segment 210 is less than that of the second segment 220. This helps to adjust the stiffness change of the first half-shaft 200 from the first segment 210 to the second segment 220, avoiding abrupt changes in the stiffness of the first half-shaft 200 between the first and second segments, thereby alleviating the stress concentration of the through hole 230 distributed in the second segment 220. The first segment 210 has relatively low stiffness; if the through hole 230 is placed in the first segment 210, it will further reduce the stiffness of the first segment 210, impairing the connection strength between the first segment 210 and the first locking structure 120 and the first planetary carrier 113a. Placing the through hole 230 in the first segment 210 will also lead to excessive oil flow resistance.

[0108] Please continue reading. Figure 4 and Figure 5 In one embodiment, the second gear ring 114b is used to drive the second half-shaft 300 via the output disk 140, and the output disk 140 is distributed between the gear ring 114b and the second half-shaft 300 along the radial direction R of the planetary reducer 100. The second locking structure 130 is used to drive the second half-shaft 300 via the output disk 140.

[0109] In this embodiment, the second gear ring 114b surrounds the outer periphery of the second sun gear 111b and the second planetary gear 112b. If the second gear ring 114b were directly connected to the second half-shaft 300, the outer diameter of the second half-shaft 300 would need to be increased, resulting in the second half-shaft 300 occupying excessive space in the planetary reducer 100. To reduce the difficulty of transmitting power from the second gear ring 114b to the second half-shaft 300, this embodiment utilizes an output disk 140 to compensate for the radial distance between the second gear ring 114b and the second half-shaft 300. The second gear ring 114b can be fixedly connected to the second half-shaft 300 via the output disk 140.

[0110] In this embodiment, the second locking structure 130 can reuse the output disk 140, reducing the number of structural components. The output disk 140 is drivenly connected to the second gear ring 114b, and the second locking structure 130 can receive the power transmitted by the second gear ring 114b through the output disk 140. The output disk 140 is drivenly connected to the second half-shaft 300, and the second locking structure 130 can establish a connection between the first half-shaft 200 and the second half-shaft 300 through the output disk 140. Since the second locking structure 130 needs to be displaced, drivingly connecting the second locking structure 130 to the output disk 140 also helps to reduce the machining of the second half-shaft 300, making it easier for the second locking structure 130 to perform its locking differential function.

[0111] Please refer to the following: Figures 5 to 7 , Figure 6 This is an exploded view of the powertrain 10 provided in the embodiments of this application. Figure 7 This is an exploded view of the powertrain 10 provided in the embodiments of this application.

[0112] In one embodiment, a second portion 122 of the first locking structure 120 extends from the second sun gear 111b. The output disk 140 includes a recess 141 recessed along the axial direction of the planetary reducer 100, opposite to the second planetary set 110b. The recess 141 accommodates the second portion 122 of the first locking structure 120 and a second locking structure 130, with a second half-shaft 300 extending into the recess 141 through its bottom. The second locking structure 130 surrounds the outer periphery of the second half-shaft 300.

[0113] In this embodiment, the second portion 122 of the first locking structure 120 extends from the second sun gear 111b toward the second locking structure 130, and the second portion 122 of the first locking structure 120 can be used to couple the second locking structure 130.

[0114] In this embodiment, since the output disk 140 needs to be connected to the second locking structure 130, the layout of the output disk 140, the second locking structure 130, and the first locking structure 120 in the planetary reducer 100 can be optimized by improving the structure of the output disk 140. Specifically, the output disk 140 includes a groove 141, which is recessed away from the second planetary gear set 110b. The second part 122 of the first locking structure 120 and the second locking structure 130 are arranged in the groove 141 of the output disk 140. The first locking structure 120 and the second locking structure 130 are arranged compactly, which helps to reduce the difficulty of coupling. The compact arrangement of the second locking structure 130 and the output disk 140 helps to improve the transmission efficiency between the output disk 140 and the second locking structure 130. The second half-shaft 300 extends into the groove 141 through the bottom of the groove 141. The projection of the second half-shaft 300 along the radial direction R of the planetary reducer 100 overlaps with the projection of the second locking structure 130, reducing the axial space occupied by the second half-shaft 300 and the second locking structure 130. The output disk 140 integrates the first locking structure 120, the second locking structure 130, and the second half-shaft 300 into the groove 141, which helps to achieve a compact layout of the first locking structure 120, the second locking structure 130, and the second half-shaft 300, reducing the volume of the planetary reducer 100.

[0115] Please continue reading. Figure 5 and Figure 6 In one embodiment, the inner diameter of the radial groove 141 along the planetary reducer 100 is smaller than the outer diameter of the second gear ring 114b.

[0116] In this embodiment, the output disk 140 integrates a portion of the second locking structure 130 and a portion of the second half-shaft 300 within the groove 141, facilitating the transmission connection between the output disk 140 and the first locking structure 120 and the second half-shaft 300, respectively, to achieve power transmission. The output disk 140 also integrates a portion of the first locking structure 120 and a portion of the second locking structure 130 within the groove 141, reducing the difficulty of coupling the second locking structure 130 with the first locking structure 120.

[0117] In this embodiment, the groove 141 needs to provide a accommodating area for the first locking structure 120, the second locking structure 130, and the second half-shaft 300, but it is also necessary to avoid the problem of the groove 141 occupying too much space. This embodiment reduces the radial space occupied by the groove 141 by adjusting its inner diameter, which helps to reduce the layout difficulty of other components in the planetary reducer 100. In one embodiment, the inner diameter of the groove 141 along the radial direction R of the planetary reducer 100 is larger than the outer diameter of at least one of the second portion 122 of the first locking structure 120 or the second locking structure 130.

[0118] Please continue reading. Figures 5 to 7 In one embodiment, the first locking structure 120 includes a first opening 123 and a second opening 124. Along the axial direction of the planetary reducer 100, the first opening 123 faces the first planetary gear set 110a, and is used to securely connect a portion of the first half-shaft 200. In another embodiment, the first opening 123 is used to securely connect a portion of the first segment 210 of the first half-shaft 200. Along the axial direction of the planetary reducer 100, the second opening 124 faces the second locking structure 130. The inner diameter of the second opening 124 is larger than the inner diameter of the first opening 123, and the second opening 124 is used to accommodate a portion of the second half-shaft 300.

[0119] This embodiment introduces a first locking structure 120 and a second locking structure 130 into a planetary reducer 100 with differential function. The first locking structure 120 and the second locking structure 130 occupy a portion of the axial space of the planetary reducer 100. To control the axial dimension of the planetary reducer 100, a second opening 124 in the first locking structure 120 facing the second locking structure 130 is used to accommodate a portion of the second half-shaft 300. This embodiment adjusts the layout of the second half-shaft 300 in the planetary reducer 100 through the second opening 124. The second half-shaft 300 is not stacked with the first locking structure 120 and the second locking structure 130 along the axial direction O of the planetary reducer 100, but rather reuses the space on the inner periphery of the first locking structure 120 and the second locking structure 130, making the overall arrangement of the planetary reducer 100 more compact. The inner diameter of the second opening 124 is larger than that of the first opening 123. This allows the second opening 124 to accommodate the second half-shaft 300 while preventing interference between the first locking structure 120 and the second half-shaft 300, thus improving the stability of power transmission.

[0120] In one embodiment, the second opening 124 of the first locking structure 120 is distributed in the second portion 122 of the first locking structure 120.

[0121] In one embodiment, the first opening 123 of the first locking structure 120 is distributed in the first portion 121 of the first locking structure 120. Alternatively, the first locking structure 120 is distributed in the first portion 121 and the second portion 122 of the first locking structure 120.

[0122] Please continue reading. Figures 5 to 7 In one embodiment, the second locking structure 130 includes a protrusion 131 that protrudes from the surface of the second locking structure 130 facing the output disk 140. The output disk 140 includes a mounting hole 142 for drivingly connecting the second locking structure 130 through the hole wall of the mounting hole 142 abutting against the protrusion 131. The length of the mounting hole 142 along the circumferential direction C of the planetary reducer 100 is greater than the length of the protrusion 131, and the length of the mounting hole 142 along the radial direction R of the planetary reducer 100 is greater than the length of the protrusion 131.

[0123] In this embodiment, the second locking structure 130 needs to transmit power to the output disk 140, and the second locking structure 130 also needs to move relative to the output disk 140. To accommodate both of these requirements of the second locking structure 130, the mounting hole 142 of the output disk 140 is used to accommodate the protrusion 131 of the second locking structure 130. When the wall of the mounting hole 142 abuts against the protrusion 131, the output disk 140 can be driven to connect with the second locking structure 130. To reduce the resistance and wear encountered by the second locking structure 130 in its movement relative to the output disk 140, the circumferential length of the mounting hole 142 is greater than the circumferential length of the protrusion 131, and the radial length of the mounting hole 142 is greater than the radial length of the protrusion 131.

[0124] In one embodiment, the mounting hole 142 penetrates the groove wall and the bottom of the groove 141 of the output disk 140.

[0125] In one embodiment, protrusion 131 protrudes from the outer peripheral surface of the second locking structure 130. In another embodiment, protrusion 131 protrudes from the end face of the second locking structure 130 along the axial direction O of the planetary reducer 100 toward the output disk 140.

[0126] In one embodiment, the second locking structure 130 includes a plurality of protrusions 131, each protrusion 131 being distributed in a mounting hole 142 of the output disk 140. In one embodiment, the number of protrusions 131 is an integer greater than or equal to 2.

[0127] Please refer to the following: Figures 6 to 8 , Figure 8 This is a schematic diagram of the pressure angle provided in the embodiments of this application.

[0128] In one embodiment, the second locking structure 130 includes transmission teeth 132, which are distributed on the end face of the second locking structure 130 facing the first locking structure 120 along the axial direction O of the planetary reducer 100. The second locking structure 130 is used to drively connect to the first locking structure 120 via the transmission teeth 132. The pressure angle of the protrusion 131 is greater than the pressure angle of the transmission teeth 132. For ease of description, the transmission teeth 132 of the second locking structure 130 are referred to as transmission teeth 132a. In one embodiment, the transmission teeth 132a have a canine tooth structure.

[0129] The pressure angle α of a gear refers to the angle between the gear tooth profile and the radial line in the normal plane. The test method for the pressure angle α is as follows: Figure 8As shown. The outer circumferential surface of the gear includes multiple teeth. Unfolding the outer circumferential surface of the gear yields a plane N. The normal plane E of each tooth is perpendicular to the tooth's extension direction. The tooth profile of each tooth on the normal plane E is denoted as L1, and the radial line of the tooth is denoted as L2. The extension direction of the radial line L2 is perpendicular to plane N. The angle between the tooth profile L1 and the radial line L2 is the pressure angle α. In this embodiment, the tooth profile of the protrusion 131 can be understood as the surface of the protrusion 131 facing the mounting hole 142 along the circumferential direction C of the planetary reducer 100. It should be noted that... Figure 8 This illustration only shows a general test method for gear pressure angle α and does not represent the specific structure of protrusion 131 and transmission tooth 132a in the embodiments of this application.

[0130] In this embodiment, the second locking structure 130 is connected to the first locking structure 120 via a transmission tooth 132a, and is also connected to the output disk 140 via a protrusion 131. When the second locking structure 130 is coupled to the first locking structure 120, the pressure angle between the transmission tooth 132a and the protrusion 131 affects the stability of the connection between them. Specifically, the output disk 140 transmits power to the second locking structure 130, and the mounting hole 142 abuts against the protrusion 131, generating a first axial force. This first axial force can push the second locking structure 130 closer to the first locking structure 120. The transmission tooth 132a of the second locking structure 130 meshes with the first locking structure 120, generating a second axial force, which is opposite in direction to the first axial force. To prevent premature decoupling between the second locking structure 130 and the first locking structure 120, the first axial force must be greater than the second axial force. To improve the stability of the connection between the first locking structure 120 and the second locking structure 130, this embodiment adjusts the pressure angle of the protrusion 131 to be greater than the pressure angle of the transmission tooth 132a, so that the second locking structure 130 and the output disk 140 can form a self-locking structure.

[0131] In one embodiment, the first locking structure 120 includes transmission teeth 132b, which are distributed on the end face of the second portion 122 of the first locking structure 120 along the axial direction O of the planetary reducer 100 toward the second locking structure 130. The transmission teeth 132b are used to engage transmission teeth 132a to couple the first locking structure 120 and the second locking structure 130. The transmission teeth 132b have a canine tooth structure.

[0132] In one embodiment, the first locking structure 120 and the second locking structure 130 can also be coupled by spline connection.

[0133] Please refer to the following: Figure 3 , Figure 5 and Figure 9 , Figure 9This is a cross-sectional view of a partial structure of the powertrain 10 provided in an embodiment of this application. For the sake of simplicity, Figure 4 , Figure 5 and Figure 9 The cross-sectional lines have been omitted.

[0134] In one embodiment, the planetary reducer 100 includes an actuator 150 for receiving electrical energy to drive a second locking structure 130 to couple with a first locking structure 120. The housing of the planetary reducer 100 includes a receiving groove 160, with the opening of the groove 160 facing a first planetary gear set 110a along the axial direction of the planetary reducer 100. A second half-shaft 300 extends into the receiving groove 160 through its bottom. The distance between the groove wall of the receiving groove 160 and the second locking structure 130 along the radial direction of the planetary reducer 100 is less than the distance between the groove wall of the receiving groove 160 and the second half-shaft 300. The bottom of the receiving groove 160 is spaced from the first planetary gear set 110a and the second planetary gear set 110b. The space between the groove wall of the receiving groove 160 and the second locking structure 130 is used to accommodate the actuator 150, which is fixedly connected to the groove wall and bottom of the receiving groove 160. For ease of description, the receiving groove 160 used to install the actuator 150 will be referred to as receiving groove 160a.

[0135] In this embodiment, the actuator 150 provides power to the second locking structure 130, enabling the second locking structure 130 to move toward the first locking structure 120, thus completing the locking of the differential function. In one embodiment, the actuator 150 includes a spring and an annular piston 151. The spring abuts against the first locking structure 120 and the second locking structure 130 along the axial direction O of the planetary reducer 100. The annular piston 151 surrounds the outer periphery of the second portion 122 of the first locking structure 120. When the actuator 150 is energized, it pushes the second locking structure 130 toward the first locking structure 120 via the annular piston 151, and the second locking structure 130 compresses the spring. When the actuator 150 is de-energized, the spring pushes the second locking structure 130 away from the first locking structure 120. In one embodiment, the inner diameter of the annular piston 151 along the radial direction R of the planetary reducer 100 is larger than the outer diameter of the protrusion 131, and the annular piston 151 along the axial direction O of the planetary reducer 100 covers a portion of the mounting hole 142 of the output disk 140. In one embodiment, the actuator 150 includes a guide structure 152, which is fixedly connected to the bottom of the groove 141 and is used to guide the annular piston 151 to move along the axial direction O of the planetary reducer 100.

[0136] In this embodiment, since the receiving groove 160a does not rotate, the actuator 150 is fixedly connected to the receiving groove 160a. Compared to a scheme where the actuator 150 is fixedly connected to the moving part, this avoids negative impacts on the transmission efficiency of the planetary reducer 100. Furthermore, as... Figure 9 As shown, the actuator 150 typically receives electrical energy via wire 153, and its installation involves wiring harness arrangement. If the actuator 150 is too close to the moving parts in the planetary reducer 100, interference and wear may occur, interfering with the normal operation of the multiple planetary gear sets 110, the first locking structure 120, and the second locking structure 130. In this embodiment, the actuator 150 is accommodated using the radial space between the wall of the receiving groove 160a and the second locking structure 130, and the actuator 150 is fixed using the walls and bottom of the receiving groove 160a. By adjusting the layout of the actuator 150 in the receiving groove 160a, clearance space is provided between the actuator 150 and the first planetary gear set 110a and the second planetary gear set 110b, facilitating the wiring harness arrangement of the actuator 150 and reducing frictional losses.

[0137] Please continue reading. Figure 5 In one embodiment, radial R actuators 150 along the planetary reducer 100 are distributed between the groove wall of the groove 141 and the groove wall of the receiving groove 160a. In this embodiment, the inner diameter of the groove 141 is smaller than the outer diameter of the second gear ring 114b. By shortening the inner diameter of the groove 141, it is beneficial to provide installation space for the actuators 150 and reduce the layout difficulty of the actuators 150.

[0138] Please refer to the following: Figure 3 , Figure 5 and Figure 10 , Figure 10 This is a schematic diagram of the powertrain provided in an embodiment of this application.

[0139] In one embodiment, the receiving slot 160a is also used to receive the second planetary gear set 110b, the first locking structure 120, and the second locking structure 130. The powertrain 10 includes an intermediate housing 101, which includes integrally formed receiving slots 160b and 160c. The receiving slot 160b is used to receive the first planetary gear set 110a and the third planetary gear set 110c, and the receiving slot 160c is used to receive the drive motor 400. The opening of the receiving slot 160b is opposite to the opening of the receiving slot 160c, and the opening of the receiving slot 160b is opposite to the opening of the receiving slot 160a.

[0140] This embodiment utilizes two separate receiving slots 160a and 160b to accommodate different structures of the planetary reducer 100, facilitating the placement of the actuator 150 at the bottom of the receiving slot 160a and reducing the installation difficulty of the actuator 150, the first locking structure 120, and the second locking structure 130. The receiving slots 160b and 160c are integrally formed, which enhances their structural strength and improves the integration of the powertrain 10. In one embodiment, the receiving slot 160a can also be considered as an end cap of the intermediate housing 101.

[0141] It should be noted that, Figure 3 The relative positions of the first planetary gear set 110a, the second planetary gear set 110b, the third planetary gear set 110c, the output disk 140, and the receiving slots 160a and 160b are shown only schematically and do not represent the actual structure and dimensions of the first planetary gear set 110a, the second planetary gear set 110b, the third planetary gear set 110c, the output disk 140, the receiving slots 160a and 160b. Figure 10 The relative positions and opening orientations of the receiving tanks a, b, and c are shown only schematically and do not represent the actual structure and dimensions of the receiving tanks a, b, and c.

[0142] In one embodiment, the third gear ring 114c is used to securely connect to the receiving groove 160b. The second planetary carrier 113b is used to securely connect to at least one of the receiving grooves 160a or 160b.

[0143] In one embodiment, the actuator 150 is an electromagnetic actuator, which includes an electromagnetic coil 154 and the receiving groove 160a is made of non-magnetic metal.

[0144] In this embodiment, after the actuator 150 is energized, the electromagnetic coil 154 generates a magnetic field. In one embodiment, the annular piston 151, under the influence of the magnetic field, pushes the second locking structure 130 to couple with the first locking structure 120. To ensure the normal operation of the actuator 150, the material of the receiving groove 160a used to fix the actuator 150 is a non-magnetic metal, which helps to reduce the risk of magnetic leakage. In one embodiment, the non-magnetic metal may be at least one of aluminum and magnesium. In one embodiment, the actuator 150 also includes a steel shell 155, which is used to house the electromagnetic coil 154 and is fixedly connected to the groove wall and bottom of the receiving groove 160a. The steel shell 155 can provide a path for magnetic flux transmission for the electromagnetic coil 154 of the actuator 150. In one embodiment, the annular piston 151 and the steel shell 155 are made of low-carbon steel to prevent residual magnetism from preventing the annular piston 151 from moving freely.

[0145] In one embodiment, the actuator is an electric motor actuator, which includes an electric motor, a reduction gear, and a cam. The electric motor drives the reduction gear, which reduces the rotational speed of the power output by the electric motor and increases the output torque. The cam converts the circular motion into axial motion.

[0146] In one embodiment, the first locking structure and the second locking structure may also be integrated into a splined sleeve, with splines formed on at least one of the inner or outer circumferential surfaces of the splined sleeve. The splined sleeve is distributed on the inner circumferential side of the sun gear of at least one planetary gear set, and the splined sleeve is movable along the axial direction of the planetary reducer. In the non-operating state, the splined sleeve is fixedly connected to one of the first half-shafts or the second half-shaft via splines. In the operating state, the splined sleeve is fixedly connected to the other of the first half-shafts or the second half-shaft via splines to achieve locking of the differential function.

[0147] In one embodiment, the annular piston can also be replaced by a fork, which is connected to a second locking structure and, driven by an actuator, pushes the second locking structure to move axially along the planetary reducer.

[0148] The planetary reducer, powertrain, and electric vehicle provided in the embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and embodiments of this application. The descriptions of the embodiments above are only for the purpose of helping to understand the methods and core ideas of this application. Furthermore, those skilled in the art will recognize that, based on the ideas of this application, there will be changes in specific embodiments and application scope. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A planetary reducer, characterized in that, The planetary reducer is used to drive the wheels of an electric vehicle through a first half-shaft and a second half-shaft respectively. The planetary reducer includes multiple planetary gear sets, a first locking structure and a second locking structure. Each planetary gear set includes a sun gear, planet gears, a planet carrier and a ring gear. The planet gears are used to drive the outer circumferential surface of the sun gear and the inner circumferential surface of the ring gear. The planet carrier is used to drive the planet gears. The plurality of planetary gear sets include a first planetary gear set and a second planetary gear set. The ring gear of the first planetary gear set is used to receive power, the sun gear of the first planetary gear set is used to drive the sun gear of the second planetary gear set, the first half-shaft is used to receive power transmitted by the planet carrier of the first planetary gear set, and the second half-shaft is used to receive power transmitted by the ring gear of the second planetary gear set, wherein: The first locking structure is used to fix the first half-shaft, and the second locking structure is used to drive the second half-shaft. When the first locking structure and the second locking structure are coupled, the first locking structure and the second locking structure are used to drive the first half-shaft and the second half-shaft.

2. The planetary reducer according to claim 1, characterized in that, Along the axial direction of the planetary reducer, a first section of the first half-shaft passes through the sun gear of the first planetary gear set and extends into the sun gear of the second planetary gear set. The gap between the first section of the first half-shaft and the sun gear of the second planetary gear set is used to accommodate a first part of the first locking structure. The outer peripheral surface of the first section of the first half-shaft is used to fix the inner peripheral surface of the first part of the first locking structure.

3. The planetary reducer according to claim 2, characterized in that, The planet carrier of the first planetary gear set extends into the gap between the sun gear of the first planetary gear set and the first segment of the first half-shaft. The outer peripheral surface of the first segment of the first half-shaft is used to fixably connect to the inner peripheral surface of the planet carrier of the first planetary gear set. The first portion of the first locking structure is spaced apart from the planet carrier of the first planetary gear set. The length of the first section of the first half-shaft extending into the sun gear of the second planetary gear set along the axial direction of the planetary reducer is greater than the length of the first portion of the first locking structure.

4. The planetary reducer according to claim 2 or 3, characterized in that, The second segment of the first half-shaft is adjacent to the first segment of the first half-shaft. The second segment of the first half-shaft is distributed on the side of the first planetary gear set away from the second planetary gear set. The outer diameter of the first segment of the first half-shaft along the radial direction of the planetary reducer is smaller than the outer diameter of the second segment of the first half-shaft.

5. The planetary reducer according to claim 4, characterized in that, The first half-shaft includes a through hole that extends through the second section of the first half-shaft and is used to connect the shaft cavity of the second section of the first half-shaft.

6. The planetary reducer according to any one of claims 1-5, characterized in that, The gear ring of the second planetary gear set is used to drive the second half-shaft through the output disc. The output disc is distributed between the gear ring and the second half-shaft along the radial direction of the planetary reducer. The second locking structure is used to drive the second half-shaft through the output disc.

7. The planetary reducer according to claim 6, characterized in that, The second part of the first locking structure extends from the sun gear of the second planetary gear set. The output disk includes a groove that is recessed away from the second planetary gear set along the axial direction of the planetary reducer. The groove is used to accommodate the second part of the first locking structure and the second locking structure. The second half-shaft extends into the groove through the bottom of the groove. The second locking structure surrounds the outer periphery of the second half-shaft.

8. The planetary reducer according to claim 7, characterized in that, The inner diameter of the groove along the radial direction of the planetary reducer is smaller than the outer diameter of the gear ring of the second planetary gear set.

9. The planetary reducer according to any one of claims 6-8, characterized in that, The first locking structure includes a first opening and a second opening. Along the axial direction of the planetary reducer, the first opening faces the first planetary gear set. The first opening is used to securely connect a portion of the first half-shaft, wherein: Along the axial direction of the planetary reducer, the second opening faces the second locking structure, the inner diameter of the second opening is larger than the inner diameter of the first opening, and the second opening is used to accommodate a portion of the second half-shaft.

10. The planetary reducer according to any one of claims 6-9, characterized in that, The second locking structure includes a protrusion that extends beyond the surface of the second locking structure facing the output disk. The output disk includes a mounting hole for actuating the protrusion through the wall of the mounting hole to drive the connection between the output disk and the second locking structure, wherein: The length of the mounting hole along the circumference of the planetary reducer is greater than the length of the protrusion, and the length of the mounting hole along the radial direction of the planetary reducer is greater than the length of the protrusion.

11. The planetary reducer according to claim 10, characterized in that, The second locking structure includes transmission teeth, which are distributed on the end face of the second locking structure facing the first locking structure along the axial direction of the planetary reducer. The second locking structure is used to drive the first locking structure through the transmission teeth, wherein: The pressure angle of the protrusion is greater than the pressure angle of the transmission tooth.

12. The planetary reducer according to any one of claims 1-11, characterized in that, The planetary reducer includes an actuator for receiving electrical energy to drive the second locking structure to couple with the first locking structure. The housing of the planetary reducer includes a receiving groove, with the opening of the receiving groove facing the first planetary gear set along the axial direction of the planetary reducer. The second half-shaft extends into the receiving groove through the bottom of the groove. The distance between the wall of the receiving groove and the second locking structure along the radial direction of the planetary reducer is less than the distance between the wall of the receiving groove and the second half-shaft. The bottom of the receiving groove is spaced apart from the first planetary set and the second planetary set. The space between the wall of the receiving groove and the second locking structure is used to accommodate the actuator. The actuator is fixedly connected to the wall and bottom of the receiving groove.

13. The planetary reducer according to claim 12, characterized in that, The actuator is an electromagnetic actuator, which includes an electromagnetic coil, and the receiving groove is made of non-magnetic metal.

14. A powertrain, characterized in that, The powertrain includes a drive motor and a planetary reducer as described in any one of claims 1-13, the first half-shaft passing through the motor shaft of the drive motor, the plurality of planetary sets of the planetary reducer further including a third planetary set, the sun gear of the third planetary set being distributed on the outer circumferential surface of the motor shaft, and the planet carrier of the third planetary set being used for transmission connection to the ring gear of the first planetary set.

15. An electric vehicle, characterized in that, The electric vehicle includes a power battery and a powertrain as described in claim 14, the powertrain being used to receive power from the power battery and to drive the wheels of the electric vehicle; or, The electric vehicle includes a power battery and a planetary reducer as described in any one of claims 1-13, the planetary reducer being used to drive the wheels of the electric vehicle.

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