A motor is a device that converts electrical energy into mechanical energy. Since Faraday invented the first electric motor, we have been inseparable from this device in our lives.Nowadays, automobiles are rapidly changing from mechanical to electric-oriented equipment, and motors are used more and more widely in automobiles. Many people may not guess how many motors are installed in their cars. The following introduction Will help you to find the motor in the car.
Motor Applications in AutomotiveWondering where the motor is in your car, the power seat is the perfect place to find it. In economy cars, motors typically provide fore-aft adjustment and backrest tilt. In premium cars, electric motors can control height adjustment. For example, seat bottom cushion tilt, lumbar support, headrest adjustment and cushion firmness can all be inseparable from motors. Other seating functions that use electric motors include power seat folding and power loading of the rear seats.Windshield wipers are the most common example of an electric motor application in a modern car. Generally, every vehicle has at least one wiper motor for the front wipers. Rear window wipers are becoming more and more popular in SUVs and cars with hatchbacks, which means that a rear wiper and corresponding motor is present on most cars. Another motor pumps washer fluid to the windshield and, in some cars, the headlights, which may have their own small wipers.Almost every car has a blower fan that circulates air in the heating and cooling system; many vehicles have two or more fans in the cabin. High-end vehicles also have fans installed in the seats for cushion ventilation and heat distribution.Windows used to be opened and closed manually, but now electric windows are common. Hidden motors are housed in every window, including the sunroof and rear window. Actuators for these windows can be as simple as relays, but safety requirements such as detection of obstacles or pinched objects lead to the use of smarter drivers, with motion monitoring and actuation force limitation.From manual to electric, car locks have become more and more convenient. The advantages of electric control include convenience features such as remote operation, and enhanced safety and intelligence functions such as automatic unlocking after a collision. Unlike power windows, power door locks must retain a manual operation option, so this affects the design of the power door lock motor and structure.Indicators on the dashboard or cluster may have evolved into light-emitting diodes (LEDs) or other types of displays, but now every dial and gauge uses small electric motors. In the category that offers convenience, other motors include common features like side mirror folding and position adjustment, as well as more moody applications such as convertible tops, retractable running boards and glass partitions between the driver and passenger. plate.Under the hood, electric motors are becoming more common in a few other places too. In many cases, electric motors are replacing belt-driven mechanical components. Examples include radiator fans, fuel pumps, water pumps and compressors. There are several advantages to changing these functions from a belt drive to an electric drive. One of the advantages is that drive motors using modern electronics are more energy efficient than using belts and pulleys, resulting in benefits such as improved fuel efficiency, reduced weight and lower emissions. Another advantage is that using a motor instead of a belt allows more freedom in the mechanical design, since the mounting positions of the pump and fan do not have to be constrained by having to attach a serpentine belt to each pulley.Development Trend of In-vehicle Motor TechnologyThe places marked in the above picture are inseparable from the motor, and, with the improvement of the electronic degree of the car, the progress of automatic driving and intelligentization, the application of the motor in the car will be more and more, and the drive of the type of the motor is also There are changes.Most electric motors in cars previously used the standard 12V automotive system. Now, dual-voltage 12V and 48V systems are becoming mainstream, and dual-voltage systems can move some of the higher current loads from the 12V battery. The advantage of using a 48V supply is a 4x reduction in current for the same power, and the accompanying weight savings in cables and motor windings. Applications for high current loads that may update to a 48V supply include starter motors, turbochargers, fuel pumps, water pumps, and cooling fans. Placing a 48V electrical system for these components may save about 10% in fuel consumption.Learn about motor typesDifferent applications require different motors, and motors can be classified in many ways.1 . Classification according to the working power supply - According to the different working power supply of the motor, it can be divided into DC motor and AC motor. Among them, AC motors are also divided into single-phase motors and three-phase motors.2. According to the working principle - according to the different structure and working principle, the motor can be divided into DC motor, asynchronous motor and synchronous motor. Synchronous motors can also be divided into permanent magnet synchronous motors, reluctance synchronous motors and hysteresis synchronous motors. Asynchronous motors can be divided into induction motors and AC commutator motors.3. According to the classification of starting and running mode - the motor can be divided into capacitor starting single-phase asynchronous motor, capacitor running single-phase asynchronous motor, capacitor starting running single-phase asynchronous motor and split-phase single-phase asynchronous motor according to the starting and running mode.4. Classification according to usage - motors can be divided into driving motors and control motors according to their usage. Driving motors are divided into motors for electric tools (including drilling, polishing, polishing, slotting, cutting, reaming, etc.), home appliances (including washing machines, electric fans, refrigerators, air conditioners, tape recorders, video recorders, DVDs, etc.) Machines, vacuum cleaners, cameras, hair dryers, electric shavers, etc.) and other general-purpose small mechanical equipment (including various small machine tools, small machinery, medical equipment, electronic instruments, etc.) motors. Control motors are further divided into stepping motors and servo motors.5. Classification according to the structure of the rotor - motors can be divided into cage induction motors (called squirrel cage asynchronous motors in the old standard) and wound rotor induction motors (called wound asynchronous motors in the old standard) according to the structure of the rotor.6. Classification according to operating speed - motors can be divided into high-speed motors, low-speed motors, constant-speed motors, and speed-regulating motors according to operating speed.Brushed DC motors are currently the traditional solution for motors in automotive body applications. These motors are simple and relatively inexpensive to drive because the brushes provide the commutation function. In some applications, brushless direct current (BLDC) motors offer significant advantages in terms of power density, resulting in reduced weight and better fuel economy and lower emissions. BLDC motors are the choice for heating, ventilation, and air conditioning (HVAC) blowers and pumps. In these applications, electric motors tend to run for long periods of time rather than momentary operation like power windows or seats, where the simplicity and cost-effectiveness of brushed motors still has an advantage.Motors suitable for electric vehiclesThe transition from fuel vehicles to pure electric vehicles will shift the core engine of the car to an electric motor drive.The motor drive system is the heart of an electric vehicle, which consists of a motor, a power converter, various detection sensors and a power supply. Motors suitable for electric vehicles include: DC motors, brushless DC motors, asynchronous motors, permanent magnet synchronous motors, and switched reluctance motors.A DC motor is a motor that converts DC electrical energy into mechanical energy, and is widely used in electric drive because of its good speed regulation performance. It also has the characteristics of large starting torque and relatively simple control. Therefore, all machinery that starts under heavy load or requires uniform speed adjustment, such as large reversible rolling mills, hoists, electric locomotives, trams, etc., are suitable for using DC motors.The brushless DC motor is very in line with the load characteristics of electric vehicles. It has low-speed and high-torque characteristics, can provide large starting torque, and meets the acceleration requirements of electric vehicles. At the same time, it can run in low, medium, high and wide speed ranges. It also has high-efficiency characteristics, and has high efficiency under light-load vehicle conditions. The disadvantage is that the motor itself is more complicated than an AC motor, and the controller is more complicated than a brushed DC motor.The asynchronous motor is an induction motor, which is a device that places the rotor in a rotating magnetic field and obtains a rotational torque under the action of the rotating magnetic field, so that the rotor rotates. The asynchronous motor has a simple structure, is easy to manufacture and maintain, and has a load characteristic close to a constant speed, which can meet the requirements of most industrial and agricultural production machinery. However, the speed of the asynchronous motor has a fixed slip rate with the synchronous speed of the rotating magnetic field, so the speed regulation is poor, and it is not as economical and flexible as the DC motor. In addition, in the application of high power and low speed occasions, asynchronous motors are not as reasonable as synchronous motors.
The permanent magnet synchronous motor is a synchronous motor that is excited by a permanent magnet to generate a synchronous rotating magnetic field. The permanent magnet acts as a rotor to generate a rotating magnetic field. The three-phase stator winding reacts through the armature under the action of the rotating magnetic field to induce a three-phase symmetrical current. Permanent magnet motors are small in size, light in weight, small in moment of inertia, and high in power density. They are suitable for the limited space of electric vehicles. In addition, they have a large torque-to-inertia ratio and strong overload capacity, especially at low speeds. They have large output torque and are suitable for computer vehicles. startup acceleration. Therefore, the permanent magnet motor has been widely recognized by the electric vehicle industry at home and abroad, and has been used in many electric vehicles.Switched reluctance motor is a new type of speed regulation motor. The speed regulation system has the advantages of both DC and AC speed regulation systems. It is the latest generation of stepless speed regulation system following the frequency conversion speed regulation system and brushless DC motor speed regulation system. It has simple and firm structure, wide speed regulation range, excellent speed regulation performance, high efficiency in the whole speed regulation range, and high system reliability. It mainly consists of four parts: switched reluctance motor, power converter, controller and position detector. The controller contains the power converter and control circuit, while the rotor position detector is installed at one end of the motor. Nowadays, the application and development of switched reluctance motors have made remarkable progress, and have been successfully used in various fields such as electric vehicle drives, general industries, household appliances, and textile machinery, with power ranging from 10W to 5MW and maximum speeds up to 100,000 r /min.In-wheel motor technology is also known as in-wheel motor technology. Its biggest feature is that it integrates the power device, transmission device and braking device into the wheel hub, which greatly simplifies the mechanical part of the electric vehicle.
The hub motor drive system is generally composed of a motor, a reduction mechanism, a brake and a heat dissipation system. The motor types of the hub motor mainly include permanent magnet, induction, and switched reluctance. The power system is divided into two types according to the rotor type of the motor: inner rotor type and External rotor type. Since the in-wheel motor has the characteristics of independent drive of a single wheel, it can be realized relatively easily whether it is front-wheel drive, rear-wheel drive or four-wheel drive. Full-time four-wheel drive is very easy to implement on a vehicle driven by a hub motor.At the same time, the in-wheel motor can achieve differential steering similar to that of a tracked vehicle through different rotation speeds or even reverse rotation of the left and right wheels, which greatly reduces the turning radius of the vehicle, and can almost achieve in-situ steering under special circumstances (but at this time the vehicle steering mechanism and The wear of tires is large), which is very valuable for special vehicles. For example, many self-balancing vehicles that are popular on the street use hub motors. However, hub motors also have disadvantages. The use of hub motors will increase the unsprung mass of the car and the moment of inertia of the hub, which will affect the handling of the vehicle. In addition, the electric braking performance of the in-wheel motor is limited, and it takes a lot of electric energy to maintain the operation of the braking system, and there are higher requirements for sealing and heat dissipation.
XINDA