DESC:POWERTRAIN FOR ELECTRIC VEHICLE
CROSS REFERENCE TO RELATED APPLICATIONS
The present application claims priority from Indian Provisional Patent Application No. 202421020625 filed on 19/03/2024, the entirety of which is incorporated herein by a reference.
TECHNICAL FIELD
Generally, the present disclosure relates to an electric vehicle. Particularly, the present disclosure relates to a powertrain for an electric vehicle.
BACKGROUND
In today's world, the importance of Electric Vehicles (EVs) is growing rapidly due to the increasing demand for eco-friendly transportation solutions that reduce carbon emissions and dependency on fossil fuels. A key component of an EV's performance is transmission system, which plays a vital role in ensuring smooth gear shifting and efficient power delivery from the motor to the wheels. Unlike traditional internal combustion engine vehicles, EVs require transmission systems that can adapt to varying driving conditions while maintaining smooth, seamless shifts for an optimal driving experience. The ability to shift gears smoothly, with minimal friction and mechanical stress, enhances the longevity of the vehicle's transmission components and contributes to a more enjoyable and efficient driving experience.
Conventionally, the electric vehicles utilize a traditional gear-shifting mechanism, and the gear selection process typically involves a manual or automatic clutch mechanism that allows the driver to engage and disengage gears. The clutch is a coupling device connecting and disconnecting the electric motor from the gearbox. Specifically, as the driver or the transmission unit shifts gears, the clutch disengages the connection between the motor and the gears, allowing for a change in the gear ratio without stalling the motor. As the gear is changed, the clutch re-engages, connecting the motor to the new gear and allowing the vehicle to continue moving. The above-mentioned system provides flexibility in controlling the power delivery from the motor to the wheels.
However, there are certain underlining problems associated with the existing or above-mentioned transmission unit for an electric vehicle. For instance, the clutches, the gear sets, and the linkages are prone to wear and tear, resulting in higher maintenance costs and mechanical failures. Further, in manual transmissions, the driver continuously engages and disengages the clutch and shift gears, which is cumbersome, particularly in stop-and-go traffic or on long drives. The constant need for driver input leads to fatigue and a less enjoyable driving experience. Additionally, conventional systems are prone to energy losses due to friction between the moving parts, resulting in lower overall efficiency. The friction losses in electric vehicles reduce battery efficiency, impacting the overall performance and range of the vehicle. Furthermore, the additional mechanical parts increase the overall weight and space required for the transmission system, which reduces energy efficiency and limits available space for other vehicle components.
Therefore, there exists a need for a transmission unit for an electric vehicle that is efficient, durable, and overcomes one or more problems as mentioned above.
SUMMARY
An object of the present disclosure is to provide a clutchless transmission unit to enable seamless gear shifts and consequently, an optimized transmission performance of an electric vehicle.
In accordance with an aspect of the present disclosure, there is provided a transmission unit for an electric vehicle, the transmission unit comprises:
- a gearbox assembly;
- a shifter motor; and
- a transmission control unit communicably coupled with a plurality of sensors, at least one inverter, and the shifter motor,
wherein the transmission control unit is configured to engage and/or disengage the gearbox assembly, from a motor associated with the electric vehicle, based on inputs received from the plurality of sensors.
The transmission unit for an electric vehicle, as described in the present disclosure, is advantageous in terms of providing a transmission unit with smoother gear transitions, reduced driver fatigue, and improved vehicle performance, without utilizing clutch assembly. Beneficially, the transmission unit’s ability to automatically and seamlessly engage or disengage the gearbox assembly from the electric motor, based on real-time sensor inputs, provides a seamless gear transition. Additionally, the transmission unit enhances overall efficiency by eliminating the mechanical complexities and energy losses associated with traditional clutch systems, thereby increasing the longevity of the transmission components and contributing to improved vehicle reliability and comfort for the driver.
In accordance with another aspect of the present disclosure, there is described a method of operating a transmission unit, via a transmission control unit, the method comprises:
- receiving inputs from a plurality of sensor to the transmission control unit;
- generating a torque demand for a current gear position based on the inputs received from the plurality of sensors;
- generating a first instruction signal to disengage the gearbox assembly from the motor;
- generating a second instruction signal to control a torque output of the shifter motor based on the generated torque demand; and
- transferring the received torque demand to the idler gear via a shifter motor gear.
Additional aspects, advantages, features, and objects of the present disclosure would be made apparent from the drawings and the detailed description of the illustrative embodiments constructed in conjunction with the appended claims that follow.
It will be appreciated that features of the present disclosure are susceptible to being combined in various combinations without departing from the scope of the present disclosure as defined by the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
The summary above, as well as the following detailed description of illustrative embodiments, is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the present disclosure, exemplary constructions of the disclosure are shown in the drawings. However, the present disclosure is not limited to specific methods and instrumentalities disclosed herein. Moreover, those in the art will understand that the drawings are not to scale. Wherever possible, like elements have been indicated by identical numbers.
Embodiments of the present disclosure will now be described, by way of example only, with reference to the following diagrams wherein:
Figure 1 illustrates a block diagram of a transmission unit for an electric vehicle, in accordance with an embodiment of the present disclosure.
Figure 2 illustrates a detailed view of a gearbox assembly engaged with a shifter motor, via an idler gear, in accordance with an embodiment of the present disclosure.
In the accompanying drawings, an underlined number is employed to represent an item over which the underlined number is positioned or an item to which the underlined number is adjacent. A non-underlined number relates to an item identified by a line linking the non-underlined number to the item. When a number is non-underlined and accompanied by an associated arrow, the non-underlined number is used to identify a general item at which the arrow is pointing.
DETAILED DESCRIPTION
The following detailed description illustrates embodiments of the present disclosure and ways in which they can be implemented. Although some modes of carrying out the present disclosure have been disclosed, those skilled in the art would recognize that other embodiments for carrying out or practicing the present disclosure are also possible.
As used herein, the term “transmission unit” refers to a component of an electric vehicle that manages the transfer of power from the electric motor to the wheels. Many EVs incorporate a single-speed transmission that allows the electric motor to deliver consistent torque and power across a wide range of speeds. Further, the transmission unit facilitates energy efficiency optimization and boosts overall vehicle performance. Additionally, some advanced EVs may employ a multi-speed transmission to further improve responsiveness and adaptability to different driving conditions. Overall, the transmission unit is essential for ensuring a smooth driving experience, maximizing the electric motor capabilities, and contributing to the vehicle's overall efficiency and performance.
As used herein, the terms “electric vehicle”, “vehicle”, and “EV” are used interchangeably and refer to a vehicle that is driven by an electric motor that draws its electrical energy from a battery and is charged from an external source. The electric vehicle includes both a vehicle that is only driven by the electric motor that draws electrical energy from the battery (all-electric vehicle) and a vehicle that may be powered by an electric motor that draws electricity from the battery and by an internal combustion engine (plug-in hybrid electric vehicle). Moreover, the ‘electric vehicle’ as mentioned herein may include electric two-wheelers, electric three-wheelers, electric four-wheelers, electric trucks, electric pickup trucks, and so forth.
As used herein, the terms “gear-box assembly” and “assembly” are used interchangeably and refer to a mechanical component that transfers power from the motor to the wheels, allowing the vehicle to operate efficiently at various speeds and conditions. The gear-box assembly consists of a set of gears housed in a protective casing working together to adjust the rotational speed of the motor output, enabling the vehicle to operate efficiently across different conditions. The assembly consists of key components such as gears, shafts, bearings, and housing, all designed to handle the torque and power output from the electric motor while maintaining smooth and quiet operation. Therefore, the gearbox assembly plays a vital role in maximizing energy efficiency, enhancing the vehicle overall performance, and contributing to the longevity of the motor.
As used herein, the term “shifter motor” refers to an electromechanical actuator responsible for automating the gear-shifting process within the transmission system. The shifter motor replaces the traditional manual clutch and gear lever, enabling smooth and precise shifts without driver intervention. Further, the shifter motor is controlled by the Transmission Control Unit (TCU), which processes data from various sensors to determine the appropriate gear. The motor engages or disengages the gears, ensuring that the transmission functions seamlessly in systems such as automated manual transmissions (AMTs), dual-clutch transmissions (DCTs), and continuously variable transmissions (CVTs). The engagement and disengagement allow for more efficient driving experiences by eliminating the need for manual shifting and reducing wear on the clutch and gear components. The two types of shifter motors used in clutchless transmission units include electric motors and electromechanical actuators. The electric motors are commonly employed in systems such as DCTs and AMTs, in which the shifter motor operates the shift forks or gear selectors to change gears. The electromechanical actuators combine electric motors with mechanical components, providing more precise and faster shifting capabilities, especially in advanced systems like CVTs.
As used herein, the term “transmission control unit” and “TCU” are used interchangeably and refer to an electronic control module responsible for managing and optimizing the operation of the transmission system without the need for a manual clutch. The TCU receives input from various sensors, such as, but not limited to, vehicle speed, engine RPM, throttle position, and gear position, and processes this data to determine the ideal time for shifting gears. In clutchless transmission systems such as AMTs, DCTs, and CVTs, the TCU controls the automated shifting process by sending signals to the shifter motor or actuators to engage or disengage the appropriate gear. The TCU operation ensures smooth, efficient gear transitions without manual intervention from the driver. The types of transmission control units used depend on the type of transmission system. For instance, in AMTs, the TCU automates the process of clutch engagement and gear shifting, mimicking a traditional manual transmission. For DCTs, the TCU works in coordination with two separate clutches to facilitate rapid and seamless gear changes. In CVTs, the TCU optimizes the adjustment of the continuously variable gear ratio to ensure smooth acceleration and fuel efficiency. The method typically involves continuous real-time analysis of sensor data, with the TCU making instantaneous decisions about gear changes based on driving conditions.
As used herein, the term “sensors” refers to devices that detect and measure various physical parameters of a vehicle and thereby provide critical data to the vehicle control systems. The sensors play a vital role in ensuring the efficient operation, safety, and performance of the vehicle by monitoring associated surrounding conditions, system states, and operating conditions. Various sensors may include (but not limited to) current sensors, voltage sensors, accelerometers, and wheel speed sensors. Additionally, sensors may also include GPS Sensors, pressure sensors, and radar sensors.
As used herein, the term “inverter” refers to an electronic device that converts direct current (DC) power, typically from a battery or other power source, into alternating current (AC) to control and drive electric motors or actuators within the transmission system. In clutchless transmissions, especially in electric and hybrid vehicles, the inverter plays a critical role in providing the necessary electrical energy for components such as shifter motors or actuators that automate gear shifting without the use of a traditional clutch. The inverter’s primary function is to ensure smooth and efficient power delivery, helping to optimize the performance of automated transmission systems such as dual-clutch transmissions (DCTs) or continuously variable transmissions (CVTs). Specifically, the two main types of inverters used in clutchless transmission units are Voltage-Source Inverters (VSIs) and Current-Source Inverters (CSIs). The voltage-source inverters are more commonly used in electric and hybrid vehicle transmission systems to control the AC motors that actuate the gear-shifting mechanism. The current-source inverters are used in certain applications for controlling the current delivered to the motor. The method of operation involves the inverter receiving DC power from the vehicle’s battery or power system and converting it into AC, which is then used to drive the electric motor or actuators that control the clutchless transmission. By precisely managing the power flow, the inverter ensures smooth gear shifts and contributes to the overall efficiency and performance of the vehicle’s transmission system.
As used herein, the term “motor” refers to any device or a machine that uses electrical energy to produce rotating motion or mechanical energy. The motor consists of a stator and a rotor. The flow of electrical current through the motor generates a magnetic field that turns the rotor, producing a mechanical movement. Various types of motors may include (but not limited to) DC shunt motors, DC series motors, AC induction motors, AC synchronous motors, and switched reluctance motors.
As used herein, the term “drive gears” refers to the set of gears that receive power from an external source and transmit the generated rotational force to driven gears within the gearbox assembly. The drive gears are mounted on a shaft and serve as the starting point for the transfer of mechanical energy in the gear assembly. The drive gear rotation causes the meshing driven gears to rotate, which in turn transmits the power throughout the gear assembly. The size and tooth configuration of the drive gear determines the gear ratio, which affects the output speed and torque of the system. The drive gears play a key role in the overall function of mechanical systems such as transmissions, differential gearboxes, and other machinery. Specifically, the drive gears are the first link in a chain of gears that powers the machine output for the operation of the vehicle.
As used herein, the term “main shaft” refers to a central rotating component in a mechanical system of the vehicle drivetrain, that transmits power from the motor to other drive components of the vehicle. The main shaft is supported by bearings at both ends, allowing it to rotate freely with minimum friction and wear. The main shaft is connected to gears or linkages that alter the speed or torque to deliver the power to the wheels. In multi-gear systems, the main shaft serves as the central hub that interacts with other shafts or gear sets to provide a range of speed options. Therefore, the main shaft is a fundamental component in ensuring the reliability, efficiency, and longevity of the vehicle drivetrain.
As used herein, the term “driven gears” refers to the gears that receive rotational power from the drive gears and transmit it to the wheels of the vehicle. The driven gear teeth mesh with the drive gear teeth, allowing the power generated by the motor to be transferred through the gear train. The driven gear is smaller or larger than the drive gear, depending on the desired output speed and torque. The role of driven gears is crucial in adjusting the mechanical output of the system, whether by increasing or decreasing speed, or altering the torque applied to a component, such as a wheel or another shaft. The driven gears are of various types, such as (but not limited to) spur gears, helical gears, or planetary gears, each serving specific purposes in power transmission. The durability and precise meshing of driven gears are critical for ensuring the smooth operation of the entire gear system, and any malfunction or misalignment may lead to inefficient power transfer or mechanical failure.
As used herein, the term “counter shaft” refers to a secondary shaft that works in coordination with the main shaft to transmit power and manage the distribution of torque. The gears mounted on the counter shaft mesh with the gears of the main shaft to adjust the speed and torque delivered to the wheels. The counter shaft rotates in the opposite direction of the main shaft and achieves the desired gearing ratios, that allow the vehicle to operate at different speeds or under varying load conditions. Consequently, the counter shaft is able to modify the rotational force from the motor and thereby optimizes the power output and efficiency of the drivetrain.
As used herein, the term “fork shaft” refers to a component that facilitates the engagement and disengagement of gears in the vehicle. The fork shaft is connected to the shift fork, which moves the gears along the transmission main shaft or countershaft to change the vehicle gear ratio. Consequently, as the shift fork moves along the fork shaft, the gears are pushed into position, enabling the selection of different gears in the gear assembly. The engagement and disengagement of gears allow the transmission to alter the power output and speed, based on the rider input. The fork shaft is mounted securely within the transmission case and provides the mechanical support for the shift fork to operate smoothly. The fork shaft ensures that the gears are aligned properly during shifting and manages the forces involved during gear engagement, preventing misalignment or damage.
As used herein, the term “shifter fork” refers to a component in a vehicle transmission system for moving gears in and out of engagement within the gearbox. The shifter fork is designed to slide along the shaft spline and push or pull the gears into appropriate positions based on the shifting of the gears. The shifter fork is connected to the shift mechanism via the fork shifter to interact with the gears and ensure the correct gear is selected for the vehicle speed or power requirements. The operation of the shifter fork is integral to smooth gear transitions and the overall functionality of the transmission. The shifter fork is paired with the shifter fork bearings to reduce friction and allow for smoother movement within the transmission housing.
As used herein, the term “drum cam gear shaft” refers to a component that is connected to a drum cam mechanism to engage or disengage gears depending on the rotational position of the counter shaft. The drum cam gear shaft interacts with other gear components to select the appropriate gear ratio based on the vehicle speed and power. The cam is a rotating cylindrical component with a series of grooves or splines that is engaged by the counter shaft, guiding the movement of other parts of the transmission system, and ensuring smooth and efficient gear changes. The drum cam gear shaft design and smoothness prevent slipping or jerking during gear shifts, as any malfunction disrupts the performance of the transmission.
As used herein, the term “star cam gear” refers to a type of mechanical gear mechanism that uses a cam-shaped structure with multiple lobes, designed to control the engagement and disengagement of gears within the transmission system. The star cam gear operates by engaging with corresponding components, such as shift forks or gear selectors, to shift gears automatically without the need for a manual clutch. In clutchless transmissions, the star gear mechanism is controlled by an actuator or electric motor, which is driven by the TCU. The star cam gear enables smooth, precise gear shifts by using its cam profile to transmit rotational motion in a way that gradually engages the appropriate gear, reducing shock and wear in the transmission system. There are primarily two types of star cam gears used in clutchless transmission units, single-lobe star cam gears and multi-lobe star cam gears. The single-lobe star cam gears are typically simpler and used in less complex systems where the number of gear shifts is limited. The multi-lobe star cam gears are more sophisticated and used in systems with a greater number of gears or more complex shifting needs. The method of operation involves the TCU sending commands to the actuator, which then controls the movement of the star cam gear. As the cam gear rotates, the lobes engage with the transmission components, shifting gears smoothly and efficiently without the need for a manual clutch. The method allows for fast, precise, and seamless gear changes, making the overall driving experience more comfortable and efficient in clutchless transmission systems.
As used herein, the term “gear position sensor” refers to a sensor that monitors the selected gear in the vehicle's transmission system. The gear position sensor provides feedback to the TCU or vehicle control system about the current gear, enabling the system to optimize power delivery, adjust torque, and ensure smooth gear shifting. In EVs with single-speed transmissions or multi-speed gearboxes, the gear position sensor helps the vehicle's control system comprehend the gear status, for managing efficiency, energy regeneration, and performance under different driving conditions. The types of gear position sensors include mechanical, magnetic, and Hall effect sensors. The components of a gear position sensor include a sensor element that detects the gear's position (such as a switch or a magnet), a linkage mechanism that connects to the transmission, and signal-processing electronics. The working principle of a gear position sensor involves detecting the physical position of the gear through mechanical or magnetic means and converting it into an electrical signal. The signal is sent to the TCU, which uses the signal to adjust the motor’s performance, accordingly, ensuring smooth transitions between gears, efficient power usage, and effective regenerative braking.
As used herein, the term “throttle position sensor” refers to a component that measures the position of the throttle pedal or the throttle valve. The throttle position sensor provides real-time data to the TCU about the driver's input on acceleration, allowing the control system to adjust the motor's power output accordingly. The sensor detects how far the throttle pedal is pressed, translating this physical movement into an electrical signal that tells the system how much power to supply to the motor. The detection helps to regulate acceleration and maintain smooth driving performance, ensuring the vehicle responds appropriately to the driver’s commands. The throttle position sensor in EVs uses tools such as potentiometers, Hall effect sensors, or resistive sensors. The key components of a TPS include a sensor element (such as a potentiometer or magnetic sensor), a mechanical linkage to the throttle, and signal-processing electronics. The working principle involves the sensor detecting changes in the position of the throttle mechanism and converting the change in position into a voltage or digital signal. The signal is sent to the TCU, which processes the information and adjusts the motor's power delivery to match the throttle input. By continuously monitoring and adjusting the throttle response, the TPS plays a significant role in controlling the vehicle's acceleration, energy efficiency, and overall driving experience.
As used herein, the term “vehicle speed sensor” refers to a device that measures the speed of a vehicle by detecting the rotation of a wheel or the movement of the vehicle. The speed sensor converts the movement into an electrical signal that is processed by the vehicle control unit. Various types of speed sensors may include (but not limited to) wheel Speed Sensors, transmission speed sensors and GPS Speed Sensors.
As used herein, the term “current sensor” refers to a device that measures and monitors the electrical current flowing through various parts of the vehicle's electrical system. Further, the accurate current measurement is essential for managing power distribution, optimizing performance, ensuring safety, and improving the overall efficiency of the EV. Specifically, the current sensors detect the current flowing through the stator windings of the motor for an efficient gear transmission of the vehicle.
As used herein, the term “voltage sensor” refers to an electronic device that monitors the voltage levels within the transmission system related to the power supplied to actuators, motors, or the Transmission Control Unit (TCU). The sensor helps to ensure that the system operates within the required voltage range for optimal performance. In clutchless transmissions, the voltage sensor plays a crucial role in providing real-time data about the electrical supply, helping to manage the energy used for shifting gears automatically. The data is important for maintaining the efficiency of the transmission system, as fluctuations in voltage affect the accuracy and timing of gear shifts. Analog voltage sensors provide continuous voltage readings and are typically used in systems where precise, real-time monitoring of voltage changes is necessary. Digital voltage sensors convert voltage readings into digital signals, which are easier to process by the TCU or other control systems. The method of operation involves the voltage sensor detecting the electrical potential across a given component or circuit in the transmission system. The sensor then transmits this data to the TCU, which uses it to adjust power delivery, ensuring that components such as the shifter motor, actuators, or inverters receive the correct voltage for optimal gear shifting and overall performance of the clutchless transmission.
As used herein, the term “torque demand” refers to a required amount of rotational force (torque) that needs to be applied to the transmission system for a specific gear to engage or to achieve a desired driving condition. The torque demand is determined by the TCU, which analyses data from various sensors (such as vehicle speed, engine speed, throttle position, and load) to calculate the necessary torque for smooth gear transitions. In clutchless transmission systems, AMTs, DCTs, and CVTs, torque demand plays a critical role in determining the gear shifts, ensuring that the vehicle performs optimally by balancing engine power, fuel efficiency, and smooth operation. The two types of torque demand in clutchless transmission units are dynamic torque demand and steady-state torque demand. The dynamic torque demand is calculated when the vehicle is accelerating or decelerating, and it adjusts to provide the necessary torque to match the changing driving conditions. The dynamic torque demand ensures smooth acceleration and deceleration during gear shifts. The steady-state torque demand refers to the torque required when the vehicle is cruising at a constant speed or under stable conditions. The method of determining torque demand involves the TCU continuously processing inputs from sensors to adjust torque requirements in real-time. Consequently, the TCU ensures that the correct torque is applied at the right moment, allowing for efficient gear changes, reducing engine strain, and improving vehicle performance and fuel efficiency.
As used herein, the term “threshold torque” refers to a minimum amount of torque required to initiate or complete a gear shift in an automated transmission system. The threshold torque is a critical parameter in ensuring smooth transitions between gears and preventing jerky or incomplete shifts. The Transmission Control Unit (TCU) uses threshold torque values to determine the optimal time to engage or disengage a gear, taking into account factors such as engine load, vehicle speed, and throttle position. In clutchless transmissions, such as Automated Manual Transmissions (AMTs), Dual-Clutch Transmissions (DCTs), and Continuously Variable Transmissions (CVTs), threshold torque is essential to prevent damage to the transmission system, ensure proper gear meshing, and achieve a seamless driving experience.
As used herein, the term “first instruction signal” refers to an initial electronic command generated by the Transmission Control Unit (TCU) that triggers the disengagement of the gearbox assembly from the motor. The first instruction signal is sent after the TCU compares the current gear position with the desired gear position, based on inputs such as vehicle speed, engine load, throttle position, and other sensor data. The first instruction signal acts as the starting point for the gear-shifting process, instructing the system to begin the transition by disengaging the gearbox from the motor. The disengagement is crucial for ensuring smooth and efficient gear shifts without causing abrupt or jerky movements in the transmission system. As the TCU determines that a gear shift is required, TCU sends the first instruction signal to the inverter or the gearbox mechanism to disengage the current gear. The process ensures that the vehicle's powertrain is disconnected from the selected gear before a new gear is engaged. The disengagement process helps to prevent unnecessary strain on the transmission system, allowing for smoother shifts and improved performance.
As used herein, the term “second instruction signal” refers to an electronic command generated by the TCU to regulate the torque output of the shifter motor based on the torque demand determined by the system. The signal is generated after the TCU evaluates various inputs, such as the vehicle's current speed, engine RPM, throttle position, and the current gear state, to calculate the required torque necessary for the next gear shift. The second instruction signal is critical for ensuring that the shifter motor applies the correct amount of torque to shift gears smoothly and efficiently, avoiding damage to the transmission system and providing a seamless driving experience. The method for generating the second instruction signal involves the TCU continuously processing data from the system's sensors to determine the appropriate torque demand at any given time. Based on the demand, the TCU adjusts the second instruction signal, directing the shifter motor to supply the necessary torque for engaging or disengaging gears. By controlling the torque output precisely, the second instruction signal ensures that the shifter motor operates within the optimal range, preventing harsh or abrupt gear shifts and improving the overall smoothness of the transmission system.
As used herein, the term “idler gear” refers to a mechanical component used in the transmission system, placed between the gearbox assembly and the shifter motor. The idler gear's primary function is to facilitate the transfer of motion and torque between the shifter motor and the gearbox without directly engaging the gears. The idler gear acts as an intermediary, ensuring that the shifter motor's rotational force is appropriately transmitted to the correct gear in the gearbox. The idler gear's teeth mesh with those of both the shifter motor's output shaft and the main gearbox input shaft, which allows for smooth, controlled shifting within the system. Consequently, the idler gear helps in maintaining the smooth operation of the transmission by preventing direct contact between the motor and the gearbox, which results in wear and inefficiency. The idler gear also serves to adjust the gear ratios when necessary, ensuring that the correct gear is selected during shifting. In many cases, the idler gear is used to enable reverse or intermediate gear selection and function to reduce the mechanical load on the primary gearbox components, increasing the system's overall reliability and performance.
In accordance with an aspect of the present disclosure, there is provided a transmission unit for an electric vehicle, the transmission unit comprises:
- a gearbox assembly;
- a shifter motor; and
- a transmission control unit communicably coupled with a plurality of sensors, at least one inverter, and the shifter motor,
wherein the transmission control unit is configured to engage and/or disengage the gearbox assembly, from a motor associated with the electric vehicle, based on inputs received from the plurality of sensors.
Referring to figure 1, in accordance with an embodiment, there is described a transmission unit 100 for an electric vehicle comprising a gearbox assembly 102, a shifter motor 104 and a transmission control unit 106 communicably coupled with a plurality of sensors 108, at least one inverter 110, and the shifter motor 104. Further, the transmission control unit 106 is configured to engage and/or disengage the gearbox assembly 102, from a motor 112 associated with the electric vehicle, based on inputs received from the plurality of sensors 108. Furthermore, the gearbox assembly 102 and the shifter motor 104 are mechanically engaged via an idler gear 130.
The Transmission Unit 100 for an electric vehicle integrates a gearbox assembly 102, a shifter motor 104, and a Transmission Control Unit (TCU) 106. The gearbox assembly 102 controls the gear ratios and manages power transmission from the motor 112 to the wheels of the electric vehicle. Further, the shifter motor 104 adjusts the position of the gears within the gearbox assembly based on control signals. Furthermore, the TCU 106 is the central processing unit that coordinates the system's operations. The TCU 106 receives inputs from a plurality of sensors 108 that monitor various vehicle parameters such as wheel speed, motor performance, torque demand, and other operational states. Additionally, the TCU 106 is communicably coupled with an inverter 110, which is responsible for converting the DC from the vehicle's battery to AC for the motor. Based on the sensor inputs and motor data, the TCU 106 sends control signals to the shifter motor 104 to engage or disengage the gearbox assembly with the motor, adjusting the gear ratios as needed. The system operates by continuously monitoring data from the sensors 108, which track parameters such as vehicle speed, torque demand, and motor RPM. The TCU 106 processes this data and calculates the optimal gear position based on the current driving conditions and performance requirements. In case the vehicle needs to change gears, the TCU 106 sends a command to the shifter motor 104 to engage or disengage specific gears within the gearbox assembly 102. The process is managed without the use of a traditional clutch, as the shifter motor 104 directly moves the gears into the desired positions. The inverter 110 adjusts the motor's speed and torque as necessary, ensuring that the motor's output is effectively managed to match the selected gear. The coordination between the TCU 106, sensors 108, inverter 110, and shifter motor 104 enables seamless power transfer and efficient operation of the electric vehicle’s drivetrain. By using the shifter motor 104 and the TCU 106, gear engagement is precise and responsive, improving vehicle performance and driving comfort. Advantageously, the integration of sensors 108 enables real-time monitoring and adaptive control, optimizing the transmission's behaviour based on driving conditions, such as speed, load, and torque demand. Additionally, by eliminating the clutch, the system reduces mechanical complexity, increases reliability, and lowers the risk of component wear. The use of an inverter 110 ensures that the electric motor operates efficiently across various speeds and loads. Therefore, the system improves energy efficiency, reduces maintenance costs, and simplifies the drivetrain architecture, providing a more cost-effective and durable solution for electric vehicles.
Referring to figure 2, in accordance with an embodiment, there is described a gearbox assembly 102 coupled with a shifter motor 104. The gearbox assembly 102 comprises a plurality of drive gears 114 mounted on a main shaft 116, a plurality of driven gears 118 mounted on a counter shaft 120, a shifter fork 122 mounted on a fork shaft 124 and a drum cam gear shaft 126 mechanically engaged with the shifter fork 122 and a star cam gear 128. Further, the gearbox assembly 102 and the shifter motor 104 are mechanically engaged via an idler gear 130. Furthermore, the shifter motor 104 is configured to receive the second instruction signal and transfer the received torque demand to the idler gear 130 via a shifter motor gear 132. The gearbox assembly 102 described consists of several key components, each contributing to the overall functionality and performance of the transmission system. The drive gears 114 are mounted on the main shaft 116, and the driven gears 118 are mounted on the counter shaft 120. The drive gears 114 and the driven gears 116 mesh with each other to transmit rotational power from the engine to the wheels. Further, the shifter fork 122, mounted on the fork shaft 124, is responsible for moving the gear selectors to change gears. Furthermore, the drum cam gear shaft 126 is mechanically engaged with the shifter fork 122, coordinating the movement, and the star cam gear 128 helps facilitate smooth engagement and disengagement of the gears. The star cam gear 128 uses a cam profile that ensures that gear shifts occur without abrupt jerking, reducing wear on the system. As the shifter fork 122 is moved by the drum cam gear shifts the gear selectors, allowing the appropriate gear to engage with minimal friction and smoothness. The star cam gear 128 plays a crucial role by acting as a mechanical interface that engages and disengages gears in a controlled manner, preventing sudden changes in torque that could damage the system. Further, the interaction between the shifter fork 122 and the drum cam gear shaft 126 ensures accurate gear positioning. Consequently, the prevention of sudden changes in the torque results in enhanced durability, reduced wear, and smoother gear transitions, leading to better driving comfort and a more reliable transmission system. Additionally, the system helps optimize the power delivery to the wheels and ensures that the gearbox components last longer and operate efficiently, especially under high-torque or heavy-duty conditions.
In an embodiment, the plurality of sensors 108 comprises a gear position sensor, a throttle position sensor, a vehicle speed sensor, a current sensor and a voltage sensor. The gear position sensor detects the current gear engaged in the gearbox, allowing the TCU 106 to determine in case a shift is required. Further, the throttle position sensor measures the input from the driver on the accelerator, providing the TCU 106 data about the vehicle’s power demand. The vehicle speed sensor helps the TCU 106 assess the vehicle's current speed to determine the most appropriate gear for the conditions. Additionally, the current sensor monitors the amount of electrical current drawn by the motor, which provides insight into the motor's power output and load conditions. Furthermore, the voltage sensor monitors the vehicle's battery voltage to ensure the system is operating within the required power limits. The sensors work together to feed critical data to the TCU 106, enabling precise control over gear shifts and motor engagement, improving the efficiency and performance of the vehicle’s transmission system. The method of operation for this system involves the TCU 106 continuously processing the data from the above-mentioned sensors. Based on the real-time information provided, the TCU 106 determines the appropriate moment to engage or disengage the gearbox and the gear to select. The dynamic adjustment ensures that the system responds quickly to changing driving conditions, such as acceleration, deceleration, or changes in terrain. Consequently, the operation of the above-mentioned sensors results in smoother and more efficient gear transitions, enhanced energy efficiency, and reduced wear on transmission components due to the precise control enabled by the sensors.
In an embodiment, the transmission control unit 106 is configured to receive the inputs from the plurality of sensors 108. The Transmission Control Unit (TCU) 106 in the transmission unit processes real-time data received from a plurality of sensors 108 placed throughout the vehicle's drivetrain. The sensors monitor various operational parameters, such as gear position, motor speed (RPM), vehicle speed, and torque demand. The TCU uses the sensor data to calculate the appropriate torque demand for the current gear position. Based on the calculation, the TCU sends a signal to the shifter motor 104, which engages or disengages the specific gears in the gearbox assembly 102. The shifter motor 104 acts without the need for a traditional clutch, directly adjusting the gear positions to provide the correct gear ratio for the desired vehicle performance. The entire process allows the transmission to shift gears smoothly and efficiently, adapting in real-time to driving conditions. The TCU's 106 ability to dynamically adjust the gear positions based on continuous feedback from the sensors results in smoother shifts, improving driving comfort and performance. By managing gear changes without a clutch, the system reduces mechanical complexity and wear on components, increasing durability and reducing maintenance costs. Additionally, the shifter motor 104 provides fast and efficient gear engagement, enhancing the overall responsiveness of the transmission.
In an embodiment, the transmission control unit 106 is configured to generate a torque demand for a current gear position based on the inputs received from the plurality of sensors 108. The Transmission Control Unit (TCU) 106 generates the appropriate torque demand for the current gear position by processing real-time data from a variety of sensors 108. The sensors monitor critical parameters such as gear position, engine speed, vehicle speed, and load conditions. Consequently, the TCU 106 computes the torque demand required for the current gear and sends the demand to the shifter motor. Specifically, based on predefined algorithms or model, the TCU 106 calculates the necessary torque for the current gear position by factoring in variables such as battery characteristics, road conditions, and desired vehicle acceleration. The algorithms typically include the use of torque maps, lookup tables, or dynamic models that correlate the sensor data (such as motor rotational speed, throttle position, and vehicle speed) to the desired torque output for a specific gear. Further, the control unit 106 uses a torque delivery model that adjusts for factors such as battery load, road gradient, and driver inputs (such as acceleration or braking). Furthermore, the shifter motor 104 then adjusts the gear positions by directly engaging or disengaging the gears without the need for a clutch. The system continuously receives updates from the sensors, enabling the TCU 106 to dynamically adjust the torque demand and control the gear shifts, ensuring optimal performance under varying driving conditions. By directly controlling the shifter motor 104 based on sensor inputs, the TCU 106 ensures precise, rapid, and seamless gear transitions. The seamless transitions result in smoother driving experiences, faster gear engagement, and reduced chances of jerky or delayed shifts. Additionally, the absence of a clutch reduces mechanical wear and tear, increasing the system's longevity and reducing maintenance costs. The overall design benefits from being simpler and more compact, offering potential improvements in energy efficiency and reducing the complexity and cost associated with traditional clutch-based systems.
In an embodiment, the transmission control unit 106 is configured to compare the generated torque demand with a threshold torque for the current gear position. The Transmission Control Unit (TCU) 106 is configured to receive inputs from a variety of sensors 108 that monitor key vehicle parameters, such as motor speed, gear position, vehicle speed, and load conditions. Based on the inputs, the TCU 106 generates a torque demand for the current gear position to optimize power transfer and vehicle performance. Subsequently, the TCU 106 then compares the generated torque demand with a threshold torque specific to the current gear. The threshold torque is a predefined value representing the maximum allowable torque for that gear without causing damage or undesirable stress on the system. For instance, in case the generated torque demand exceeds the threshold, the TCU 106 adjust the system, either by reducing the motor’s output or shifting to a more suitable gear to prevent overloading. Consequently, the shifter motor 104 then adjusts the gear positions based on the commands, ensuring that the transmission remains within safe operational limits. The proactive monitoring and adjustment prevent the system from exceeding torque limits, which helps to avoid mechanical stress and damage. The TCU’s 106 real-time comparison of torque demand and threshold torque enables smoother, more efficient gear shifts without the need for a clutch. As a result, the system minimizes wear and tear, extends the lifespan of key components, and reduces maintenance requirements. Moreover, the dynamic torque management leads to better energy efficiency and smoother driving experiences, as the vehicle’s drivetrain is constantly optimized for the best balance between power output and mechanical safety.
In an embodiment, the transmission control unit 106 is configured to change the current gear position based on the comparison and generate a first instruction signal to disengage the gearbox assembly 102 from the motor 112. The Transmission Control Unit (TCU) 106 receives input from a range of sensors 108 that monitor parameters such as vehicle speed, motor speed (RPM), torque demand, and current gear position. Based on the information, the TCU 106 compares the generated torque demand with the torque limits for the current gear position. Specifically, as the TCU 106 determines that the current gear needs to be changed (for instance, when the torque exceeds the safe threshold for that gear), the TCU 106 generates the first instruction signal. The signal instructs the shifter motor 104 to disengage the gearbox assembly 102 from the motor 112, effectively shifting the vehicle out of the current gear. Subsequently, the shifter motor 104 then performs the operation by adjusting the gearbox’s gear positions to either engage a higher or lower gear, depending on the system's requirements. The system operates smoothly without the need for a clutch, relying solely on the precise control of the shifter motor. By disengaging the gearbox from the motor as required, the TCU 106 ensures that the system operates within safe parameters, preventing mechanical damage and avoiding inefficient power transfer. The lack of a traditional clutch simplifies the system, reducing wear on mechanical components, such as friction plates, and lowering maintenance costs. Additionally, by using the shifter motor 104 to engage and disengage gears directly, the transmission system achieves smoother gear shifts and improves responsiveness, which leads to a more comfortable and efficient driving experience.
In an embodiment, the at least one inverter 110 is configured to receive the first instruction signal and disengage the gearbox assembly 102 from the motor 112. The Transmission Control Unit (TCU) 106, after comparing the torque demand with the threshold torque for the current gear, generates a first instruction signal to disengage the gearbox assembly 102 from the motor 112. The inverter 110, which controls the motor's 112 power flow, receives the first instruction signal. Subsequently, the inverter 110 adjusts the electrical input to the motor, effectively disengaging the gearbox assembly from the motor 112. The shifter motor 104, controlled by the TCU 106, then repositions the gears in the gearbox assembly 102 to the desired new gear. Consequently, as the appropriate gear is selected, the inverter 110 restores the power flow to the motor 112, engaging the gearbox with the motor 112 again. The above-mentioned process ensures that the gear shifting occurs without the need for a clutch, relying solely on electronic and motorized control for disengagement and engagement resulting in smoother, more efficient gear shifts, as the motor is decoupled from the gearbox without mechanical friction. Further, the inverter's 110 role in controlling the power flow to the motor 112 ensures that gear transitions are precisely managed, reducing stress on the drivetrain and enhancing overall system reliability. The design reduces the mechanical complexity of the transmission, leading to fewer components that can wear out, which lowers maintenance costs and improves durability. Additionally, the above-mentioned operation of the inverter offers greater energy efficiency since the system only applies the required torque when the gearbox is properly engaged, making a more efficient and cost-effective solution for electric vehicle drivetrains.
In an embodiment, the transmission control unit 106 is configured to generate a second instruction signal to control a torque output of the shifter motor 104 based on the generated torque demand. The Transmission Control Unit (TCU) 106 is responsible for managing the torque output of the shifter motor 104, ensuring precise gear shifts. The TCU 106 continuously monitors inputs from various sensors 108 to assess the torque demand based on factors such as, vehicle speed, load, and current gear position. As the torque demand is generated, the TCU 106 processes this information and generates a second instruction signal that controls the torque output of the shifter motor 104. The second instruction signal directs the shifter motor 104 to apply the necessary torque to engage or disengage gears in the gearbox assembly 102. Further, by adjusting the torque output of the shifter motor 104, the TCU 106 ensures that the gears shift smoothly, providing the desired power transfer and performance without the need for a clutch. The ability of the TCU 106 to dynamically adjust the torque output of the shifter motor 104 ensures that gear shifts are smooth and responsive, improving the overall driving experience. The system eliminates the mechanical complexity typically associated with clutch-based transmissions, resulting in reduced wear and tear on components, lower maintenance costs, and improved system reliability. Additionally, the continuous adjustment of the motor’s torque output based on driving conditions ensures optimal power transfer and energy efficiency, contributing to better vehicle performance and longer component life.
In an embodiment, the gearbox assembly 102 and the shifter motor 104 are mechanically engaged via an idler gear 130. Specifically, the idler gear 130 serves as an intermediary component that links the shifter motor 104 to the gearbox, allowing the motor to effectively control the gear shifting process. As the Transmission Control Unit (TCU) 106 generates the necessary command for a gear change, the shifter motor 104 applies torque through the idler gear 130, which then transmits this torque to the gearbox assembly 102. The idler gear 130 ensures that the movement from the shifter motor 104 is accurately transmitted to the gearbox, facilitating the engagement or disengagement of the appropriate gears. Particularly, as the shifter motor 104 rotates, the idler gear 130 adjusts the relative position of the gears in the gearbox assembly 102, enabling smooth gear transitions based on the torque demand provided by the TCU 106. The use of an idler gear 130 in this configuration offers several technical advantages. Firstly, the idler gear 130 allows the shifter motor 104 to be mechanically decoupled from direct contact with the gears in the gearbox, providing flexibility in the design and minimizing the complexity of the motor-gear connection. The idler gear 130 ensures that the torque from the shifter motor 104 is transmitted efficiently to the gearbox, promoting smoother, more precise shifts and reducing mechanical backlash or slippage. The mechanical coupling leads to improved reliability, as the idler gear 130 acts as a buffer, absorbing any shocks or vibrations from the motor. Furthermore, the system’s design eliminates the need for a clutch, reducing maintenance and wear on traditional components, making a more durable and cost-effective solution. Finally, the idler gear 130 helps to optimize the vehicle’s power delivery, enhancing overall driving performance and energy efficiency.
In an embodiment, the shifter motor 104 is configured to receive the second instruction signal and transfer the received torque demand to the idler gear 130 via a shifter motor gear 132. The shifter motor 104 is responsible for transferring the torque demand received from the Transmission Control Unit (TCU) 106 to the idler gear 130. The TCU 106 generates a second instruction signal, which is based on the real-time torque demand for the vehicle’s current gear position. The shifter motor 104 adjusts output torque accordingly and transfers it to the idler gear 130 via a shifter motor gear 132. Subsequently, the shifter motor gear 132 engages with the idler gear 130, transferring the necessary torque from the motor 112 to the idler gear 130. The idler gear 130 then transmits the torque to the gearbox assembly 102, facilitating the engagement or disengagement of gears within the transmission system. The above-mentioned setup allows for precise control of gear shifts without the need for a clutch, ensuring smooth transitions between gears. The primary technical advantage of the design is the efficient and controlled transmission of torque from the shifter motor 104 to the idler gear 130, enabling precise gear changes without the need for a traditional clutch mechanism. By using the shifter motor gear 132 to transfer torque, the system allows for quick and smooth engagement of gears, ensuring optimal vehicle performance and responsiveness. The said approach reduces the mechanical complexity of the system, as it eliminates the need for friction-based components like a clutch, lowering maintenance requirements and enhancing the system’s durability. Additionally, the absence of a clutch reduces wear and tear, while the precise control of torque demand enables more efficient power transfer, contributing to improved energy efficiency and a smoother driving experience. Overall, the system increases the reliability, efficiency, and cost-effectiveness of the transmission in the electric vehicle.
In an embodiment, the idler gear 130 is configured to transfer the received torque demand to a star cam gear 128. The idler gear 130 serves as a critical intermediary component that transfers the torque demand received from the shifter motor 104, via the shifter motor gear 132, to the star cam gear 128. Particularly, as the idler gear 130 is engaged and receives the torque from the shifter motor 104, it rotates and transmits the torque to the star cam gear 128. The star cam gear 128 is typically designed with specific geometry that helps in the precise control of the movement of the gearbox components. The interaction between the idler gear 130 and the star cam gear 128 ensures that the torque demand is efficiently passed through to the appropriate mechanism within the gearbox assembly, enabling the precise shifting of gears. The process allows for smooth and controlled gear engagement without the need for a clutch, as the torque is seamlessly transferred through the gears in the system. The star cam gear 128 plays a key role in controlling the position of the gears by converting the rotational force received from the idler gear 130 into the precise movement needed for gear engagement. The above-mentioned configuration allows for precise and seamless shifting of gears, which enhances overall vehicle performance and driving experience. Additionally, the system reduces mechanical complexity by eliminating the need for a traditional clutch and relying on motorized gear shifting. The result is a transmission system that experiences reduced wear and tear on the components, as well as lower maintenance costs, while also providing improved efficiency and smoother operation.
In an embodiment, the star cam gear 128 is configured to adjust the angular position of the drum cam gear shaft 126 to control the engagement or disengagement of the plurality of driven gears 118 via the shifter fork 122. The star cam gear 128 receives the torque from the idler gear 130, transferred from the shifter motor 104. The star cam gear's 128 rotational movement is used to manipulate the position of the drum cam gear shaft 126, which, in turn, controls the engagement and disengagement of the plurality of driven gears 118. The movement is achieved via the shifter fork 122, which is mechanically connected to the drum cam gear shaft 126. Specifically, as the star cam gear 128 rotates, it adjusts the angular position of the drum cam gear shaft 126, moving the shifter fork 122 to either engage or disengage the driven gears within the gearbox assembly 102, facilitating smooth gear shifts without the need for a clutch. Consequently, by adjusting the angular position of the drum cam gear shaft 126, the system ensures that the shifter fork 122 moves exactly to the correct position to engage or disengage the driven gears 118 in the gearbox. The method allows for smoother and more accurate gear shifts since the motion of the shifter fork 122 is precisely controlled by the angular position of the drum cam gear shaft 126. The smooth and accurate engagement of gears reduces wear and tear on the system, extending the lifespan of the components. Additionally, the design contributes to a more efficient, cost-effective, and reliable transmission system for electric vehicles, providing an optimized driving experience with minimal maintenance requirements.
In accordance with a second aspect, there is described a method of operating a transmission unit, via a transmission control unit, the method comprises:
- receiving inputs from a plurality of sensor to the transmission control unit;
- generating a torque demand for a current gear position based on the inputs received from the plurality of sensors;
- generating a first instruction signal to disengage the gearbox assembly from the motor;
- generating a second instruction signal to control a torque output of the shifter motor based on the generated torque demand; and
- transferring the received torque demand to the idler gear via a shifter motor gear.
Figure 3 describes a method 200 of operating a transmission unit, via a transmission control unit. The method 200 starts at a step 202. At the step 202, the method 200 comprises receiving inputs from a plurality of sensor 108 to the transmission control unit 106. At a step 204, the method 200 comprises generating a torque demand for a current gear position based on the inputs received from the plurality of sensors 108. At a step 206, the method 200 comprises generating a first instruction signal to disengage the gearbox assembly 102 from the motor 112. At a step 208, the method 200 comprises generating a second instruction signal to control a torque output of the shifter motor 104 based on the generated torque demand. At a step 210, the method 200 comprises transferring the received torque demand to the idler gear 130 via a shifter motor gear 132.
In an embodiment, the method 200 comprises comparing the generated torque demand with a threshold torque for the current gear position.
In an embodiment, the method 200 comprises changing the current gear position based on the comparison and generate a first instruction signal to disengage the gearbox assembly 102 from the motor 112.
In an embodiment, the method 200 comprises receiving the first instruction signal and disengage the gearbox assembly 102 from the motor 112.
In an embodiment, the method 200 comprises transferring the received torque demand to the idler gear 130 via a shifter motor gear 132.
In an embodiment, the method 200 comprises comparing the generated torque demand with a threshold torque for the current gear position. Further, the method 200 comprises changing the current gear position based on the comparison and generate a first instruction signal to disengage the gearbox assembly 102 from the motor 112. Furthermore, the method 200 comprises receiving the first instruction signal and disengage the gearbox assembly 102 from the motor 112. Furthermore, the method 200 comprises transferring the received torque demand to the idler gear 130 via a shifter motor gear 132.
In an embodiment, the method 200 comprises receiving inputs from a plurality of sensor 108 to the transmission control unit 106. Furthermore, the method 200 comprises generating a torque demand for a current gear position based on the inputs received from the plurality of sensors 108. Furthermore, the method 200 comprises generating a first instruction signal to disengage the gearbox assembly 102 from the motor 112. Furthermore, the method 200 comprises generating a second instruction signal to control a torque output of the shifter motor 104 based on the generated torque demand. Furthermore, the method 200 comprises transferring the received torque demand to the idler gear 130 via a shifter motor gear 132.
Based on the above-mentioned embodiments, the present disclosure provides significant advantages such as (but not limited to) smoother gear transitions, reduced driver fatigue, and improved vehicle performance, enhances overall efficiency by eliminating the mechanical complexities and energy losses associated with traditional clutch systems.
In the description of the present invention, it is also to be noted that, unless otherwise explicitly specified or limited, the terms “disposed,” “mounted,” and “connected” are to be construed broadly, and may for example be fixedly connected, detachably connected, or integrally connected, either mechanically or electrically. They may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.
Modifications to embodiments and combinations of different embodiments of the present disclosure described in the foregoing are possible without departing from the scope of the present disclosure as defined by the accompanying claims. Expressions such as “including”, “comprising”, “incorporating”, “have”, and “is” used to describe and claim the present disclosure are intended to be construed in a non-exclusive manner, namely allowing for items, components or elements not explicitly described also to be present. Reference to the singular is also to be construed to relate to the plural where appropriate.
Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the present disclosure, the drawings, and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.
,CLAIMS:WE CLAIM:
1. A transmission unit (100) for an electric vehicle, the transmission unit (100) comprises:
- a gearbox assembly (102);
- a shifter motor (104); and
- a transmission control unit (106) communicably coupled with a plurality of sensors (108), at least one inverter (110), and the shifter motor (104),
wherein the transmission control unit (106) is configured to engage and/or disengage the gearbox assembly (102), from a motor (112) associated with the electric vehicle, based on inputs received from the plurality of sensors (108).

2. The transmission unit (100) as claimed in claim 1, wherein the gearbox assembly (102) comprises:
- a plurality of drive gears (114) mounted on a main shaft (116);
- a plurality of driven gears (118) mounted on a counter shaft (120);
- a shifter fork (122) mounted on a fork shaft (124); and
- a drum cam gear shaft (126) mechanically engaged with the shifter fork (122) and a star cam gear (128).

3. The transmission unit (100) as claimed in claim 1, wherein the plurality of sensors (108) comprises a gear position sensor, a throttle position sensor, a vehicle speed sensor, a current sensor and a voltage sensor.

4. The transmission unit (100) as claimed in claim 1, wherein the transmission control unit (106) is configured to receive the inputs from the plurality of sensors (108).

5. The transmission unit (100) as claimed in claim 1, wherein the transmission control unit (106) is configured to generate a torque demand for a current gear position based on the inputs received from the plurality of sensors (108).

6. The transmission unit (100) as claimed in claim 1, wherein the transmission control unit (106) is configured to compare the generated torque demand with a threshold torque for the current gear position.

7. The transmission unit (100) as claimed in claim 1, wherein the transmission control unit (106) is configured to change the current gear position based on the comparison and generate a first instruction signal to disengage the gearbox assembly (102) from the motor (112).

8. The transmission unit (100) as claimed in claim 1, wherein the at least one inverter (110) is configured to receive the first instruction signal and disengage the gearbox assembly (102) from the motor (112).

9. The transmission unit (100) as claimed in claim 1, wherein the transmission control unit (106) is configured to generate a second instruction signal to control a torque output of the shifter motor (104) based on the generated torque demand.

10. The transmission unit (100) as claimed in claim 1, wherein the gearbox assembly (102) and the shifter motor (104) are mechanically engaged via an idler gear (130).

11. The transmission unit (100) as claimed in claim 2, wherein the shifter motor (104) is configured to receive the second instruction signal and transfer the received torque demand to the idler gear (130) via a shifter motor gear (132).

12. The transmission unit (100) as claimed in claim 2, wherein the idler gear (130) is configured to transfer the received torque demand to a star cam gear (128).

13. The transmission unit (100) as claimed in claim 2, wherein the star cam gear (128) is configured to adjust the angular position of the drum cam gear shaft (126) to control the engagement or disengagement of the plurality of driven gears (118) via the shifter fork (122).

14. A method of operating a transmission unit, via a transmission control unit, the method comprises:
- receiving inputs from a plurality of sensor (108) to the transmission control unit (106);
- generating a torque demand for a current gear position based on the inputs received from the plurality of sensors (108);
- generating a first instruction signal to disengage the gearbox assembly (102) from the motor (112);
- generating a second instruction signal to control a torque output of the shifter motor (104) based on the generated torque demand; and
- transferring the received torque demand to the idler gear (130) via a shifter motor gear (132).