motor

motor

This data is reviewed by the project of data compilation and application of Science Encyclopedia of science popularization in China.

"Motor" is transliteration of English motor, which means motor and engine. The working principle is that the starter rotor is driven to rotate through the force rotation of the electrified coil in the magnetic field, and the pinion on the rotor drives the engine flywheel to rotate. The technology product was first used in automobile industry in 1912.

Basic meaning

Electronic starter is now commonly referred to as the motor, also known as

Starter

. It drives the starter rotor to rotate through the force rotation of the electrified coil in the magnetic field, and the pinion on the rotor drives the engine flywheel to rotate, so as to drive the crankshaft to rotate and start the car. New low-cost spark plug and starter with ceramic core base lay the technical foundation for automobile development.

The electronic starter abandons the bulky and dangerous hand crank, making the car driving more safe, easy and convenient, especially favored by the vast number of new consumer groups including women. At that time, Henry Lilan, the manager of Cadillac branch of general motors, immediately recognized the potential of this technological achievement, and soon applied it as a standard configuration in the company's 1912 Cadillac model, which was also named "crank less car". The advent of electronic starter is still recognized as the most influential automobile innovation in the 20th century.

classification

< ol > < li > hydraulic motor: Traditionally, it is an energy conversion device that outputs rotary motion and converts hydraulic energy provided by hydraulic pump into mechanical energy. < / Li > < li > high speed motor: gear motor has the advantages of small volume, light weight, simple structure, good processability, insensitive to oil pollution, impact resistance and small inertia. The disadvantages include large torque pulsation, low efficiency, small starting torque (only 60% - 70% of rated torque) and poor stability at low speed. The blade motor is a hydraulic motor in which the blades in the rotor slot contact with the shell (stator ring) and the rotor rotates under the action of the inflow liquid. Compared with other types of motors, vane motor has the advantages of compact structure, small outline size, low noise and long service life. Its inertia is smaller than that of plunger motor, but its anti pollution ability is worse than that of gear motor, and its speed can not be too high. Generally, it works below 200 R / min. The vane motor is unstable when the load changes or low speed due to the large leakage. < / Li > < li > radial piston motor: with good reverse characteristics, the motor operation is absolutely quiet, suitable for servo system. It can work as motor or pump in both directions. < / Li > < li > axial piston motor: it is a kind of cycloid hydraulic motor with rolling bearing support, which adopts the overall structure design of output shaft and flow distribution mechanism, inlaid stator and rotor, rolling bearing support at both ends, and special imported rotary dynamic seal ring, so that the motor can work under high back pressure. < / Li > < li > low speed hydraulic motor: simple structure, reliable operation, many varieties and specifications, low price. Its disadvantage is that its volume and weight are large, and its torque pulsation is large. < / Li > < li > axial piston motor: it is a kind of cycloid hydraulic motor with rolling bearing support, which adopts the overall structure design of output shaft and flow distribution mechanism, inlaid stator and rotor, rolling bearing support at both ends, and special imported rotary dynamic seal ring, so that the motor can work under high back pressure. < / Li > < li > cycloid motor: it is a small, low-speed, high torque hydraulic motor with internal meshing cycloid gear. Its structure is simple, low speed performance is good, short-term overload capacity is strong. There is a stator and a movable blade in the cycloid motor. The stator, blade and transmission shaft divide the motor into two cavities. Each cavity has an oil port. When one oil port enters the oil, the other oil outlet pushes the blade to swing. < / Li > < li > piston pneumatic motor: it is composed of connecting rod, crankshaft, piston, cylinder, body, valve, etc. Compressed air through the valve, in turn to the cylinder supply, so as to expand work, through the connecting rod to push the crankshaft rotation. Its work mainly comes from gas expansion work.

form

This part consists of an inner ring gear and a matching gear or rotor. The inner gear ring and the shell can be fixed together, and the oil entering from the oil port pushes the rotor to revolve around a central point. The slowly rotating rotor is driven by a spline shaft, and the output is a cycloid hydraulic motor. After the first cycloid motor came out, after decades of evolution, another concept of motor began to form. This kind of motor is equipped with rollers in the built-in gear ring. The motor with rollers can provide higher starting and running torque. The rollers reduce friction and improve efficiency. Even at very low speed, the output shaft can produce stable output. By changing the direction of input and output flow, the motor can change direction quickly and produce equal value torque in two directions. Each series of motor has a variety of displacement to meet the requirements of speed and torque.

working principle

Working principle of starter

The control device of automobile starter includes electromagnetic switch, starting relay and ignition starting switch lamp parts, in which the electromagnetic switch is made together with the starter.

1、 Electromagnetic switch

1. Structural characteristics of electromagnetic switch

Electromagnetic switch is mainly composed of electromagnet mechanism and motor switch. The electromagnet mechanism is composed of a fixed iron core, a movable iron core, a suction coil and a holding coil. The fixed iron core is fixed, and the movable iron core can move axially in the copper sleeve. The front end of the movable iron core is fixed with a push rod, the front end of the push rod is installed with a switch contact plate, and the rear section of the movable iron core is connected with a shift fork by an adjusting screw and a connecting pin. A return spring is installed outside the copper sleeve to reset the movable parts such as the movable iron core.

2. Working principle of electromagnetic switch

When the direction of the magnetic flux generated by the attraction coil and the holding coil is the same, the electromagnetic attraction is superimposed on each other, which can attract the movable iron core to move forward until the contact plate at the front end of the push rod connects the electric switch contact and the main circuit of the potential motor.

When the magnetic flux generated by the attraction coil and the holding coil is in the opposite direction, the electromagnetic attraction counteracts each other. Under the action of the return spring, the movable parts such as the movable iron core automatically reset, the contact plate and the contact are disconnected, and the main circuit of the motor is disconnected.

2、 Start relay

The structure diagram of starting relay is composed of electromagnet mechanism and contact assembly. The coil is respectively connected with the ignition switch terminal and the grounding terminal "e" on the shell, the fixed contact is connected with the starter terminal "s", and the movable contact is connected with the battery terminal "bat" through the contact arm and the bracket. The contact of starting relay is normally open. When the coil is energized, the core of relay generates electromagnetic force to close the contact, thus connecting the circuit of attraction coil and holding coil controlled by relay.

1. Control circuit

The control circuit includes start relay control circuit and starter electromagnetic switch control circuit.

The control circuit of starting relay is controlled by ignition switch, and the controlled object is relay coil circuit. When the ignition switch is turned on, the current flows from the positive pole of the battery to the ammeter through the starter power terminal, and from the ammeter to the negative pole of the battery through the ignition switch and the relay coil. Therefore, the relay core produces strong electromagnetic force, and the relay contact is closed to connect the control circuit of starter electromagnetic switch.

2. Main circuit

Battery positive pole → starter power terminal → electromagnetic switch → excitation winding → armature winding → grounding → battery negative pole, so the starter generates electromagnetic torque and starts the engine.

fault analysis

Starting Fault Analysis of electronic injection vehicle:

The engine can start normally must have three essential factors: compression, spark and mixture. If a certain element works abnormally, it will cause the engine can not start or difficult to start. There are many factors leading to the start failure of EFI engine. The failures analyzed below are all occurred under the conditions of battery voltage, normal operation of starting system, good compression and spark of engine, and normal operation of exhaust purification device.

Generally speaking, the start-up faults are unable to start and difficult to start, among which the start-up difficulty is divided into cold start difficulty and hot start difficulty.

1、 Can't start

The engine can not start and has no sign of ignition, which is generally caused by no fuel injection. The main reasons are as follows:

1. Speed signal system fault

The engine speed and crankshaft position sensor detects the speed signal and provides the crankshaft position signal when the engine is working, which is the main basis and basis of the control system. If the sensor or its circuit fails, the ECU can't receive the speed signal and crankshaft position signal, it can't control the fuel injection and ignition timing correctly, and there will be the phenomenon that the fuel injector doesn't work and the spark plug doesn't jump. Check with stethoscope and timing light to confirm whether the fuel injector and spark plug are working.

In case of the above fault, the general self diagnosis system can display the fault code, so the speed sensor, No. 1 and No. 2 camshaft position sensor and their circuits should be checked comprehensively. First, disconnect the connector of each sensor and check their resistance. If the resistance is abnormal, replace it. If it is normal, check whether the wiring and connector between ECU and each sensor are normal.

2. Fuel pump and control circuit fault

If the fuel pump or control circuit fails, there will also be no fuel pressure in the fuel supply system. Even if the injector works normally, the fuel can not be injected normally. The inspection method is: connect diagnostic plug terminal + B and FP with short wiring, then turn on the ignition switch (do not start), and check the oil inlet hose

Chinese PinYin : Ma Da