A clutch is a transmitter of rotating energy from one end of the shaft to the other. This device is in most electric motors for the distribution of mechanical energy. There is no universal coupling in design. It can have various forms and design features.
Device
An electromagnetic coupling, like any other, is a combination of the following parts:
- leading, collecting motor power;
- slave, transmitting this power further to the regulatory authorities.
If you connect these parts without displacing, you get the part is constantly connecting.
In the automotive industry, couplings are widely used, the two main parts of which are connected under the influence of an electric field and magnetic.
Due to this, a connection to the engine occurs without the use of mechanical force, and this also makes it possible to connect in independent positions. Sometimes the electromagnetic coupling allows the regulation of rotational frequencies in the control system.
Types
Couplings are divided as follows:
- communication of the driven and leading parts is carried out mechanically;
- the connection between the main parts is carried out by induction. Such a connection is possible due to the magnetic field.
Mechanical include:
- frictional. The main parts of this coupling are held together by electromagnetic forces. They can be made with a different number of disks, and also have a different friction surface (conical or cylindrical in shape);
- powder. In these structures, the driven part is connected to the leading part by a special ferromagnetic powder, which fills the space between the components of the mechanism. This powder is magnetized and tightly holds the parts together;
- gear (one more name - "cam"). Under the influence of an electromagnet, the main two parts are fastened by the teeth located on them.
Induction refers to:
- asynchronous. In this mechanism, due to the rotational movements of the leading part, an electromagnetic action is generated in the driven part. This part is also called a slip clutch;
- synchronous. Due to the action of permanent magnets at different ends of this part, under the influence of a current flowing through the coil, a field appears that fastens both its parts;
- hysteretic coupling electromagnetic. As the name implies, the fastening of parts occurs by the phenomenon of hysteresis when a magnetically solid body is magnetized.
Any of the above principles of operation does not change the main purpose of the coupling: conversion of mechanical energy at the input to it at the output.
For control and automatic systems, all types of couplings can be used .
The operation of induction elements corresponds to the operation of an electric motor. Therefore, the following devices are most widely used:
- ferro-powder with electromagnetic control;
- electromagnetic friction clutches.
Ferro-powder with electromagnetic control
In such a part, it is possible to connect the parts both rigidly and with slippage of the follower from the lead.
Due to this, it is possible to adjust the speed of the drive mechanism without interfering with the speed of the drive motor itself.
The construction of the element is as follows. Both parts of the coupling are steel cylinders, which are magnetic cores. In the driven part there is a groove to which the field winding is brought. She, in turn, is connected to a power source using slip rings together with a brush. The space between the parts is filled with a ferromagnetic mixture. It may be powdered or liquid.
Principle of operation
When a constant voltage is applied to the winding, a current is generated which forms an exciting current. It passes through a ferromagnet and the latter is magnetized, its particles create magnetized chains.
The chains are located in the direction of the magnetic field and its lines of force. The resulting force of attraction from the chains and fastens the parts of the coupling. The adhesion force depends on the magnitude of the current that flows through the chains. With an increase in the effect of current, a supersaturation of the material occurs, the adhesion force decreases, thus, an element with slippage can be created.
Friction
When a force closure occurs in a mechanical connection, then the part can be called a friction clutch or a friction clutch. It is possible to connect such a part with engines that are driven under heavy load. Structurally, these elements can be made of one or more disks with different design of the friction surface: in the form of a cylinder or cone.
Principle of operation
Surfaces subject to friction are connected by an electromagnetic field. It is impossible to regulate the torque of such a friction clutch, it is constant. It is not subject to change under the influence of a change in the magnitude of the current. This coupling can amplify power with a coefficient of more than 30.
Electromagnetic elements are subdivided depending on their area of application.
Electromagnetic coupling ETM
Only this part is capable of protecting devices and various mechanisms from pulse overloads.
It reduces idle losses. This comprehensively increases the likelihood of engine starting even at high loads. The electromagnetic coupling is subdivided into:
- contactless;
- contact;
- brake.
Air conditioning compressor clutch
In the front part of the compressor, it is it that is installed. It consists of the main elements: plate, pulley, electromagnetic coil.
The plate attaches directly to the shaft, and the coil and pulley are located on the front cover. When the power supply, creating a magnetic field, begins, the plate is attracted to the pulley and the compressor shaft moves. The pulley rotates together with the plate.
If the electromagnetic clutch is broken, it can be repaired independently.
For a successful repair, you must correctly diagnose the cause of the malfunction. If the compressor clutch breaks down, a burning odor may be felt and noise may be heard. Knocking usually occurs when the bearing needs to be replaced. There are such malfunctions that only the master can diagnose if special equipment is available.
If the question arose of replacing such a part as an electromagnetic clutch (GAZelle is no exception), then problems with finding the necessary equipment should not arise. Well, if the breakdown was detected on time. This will avoid additional costs in the event of failure of other related engine parts.
Couplings for different equipment are also different, and in order not to make a mistake when buying on your own, you can contact a service center.
If the electromagnetic clutch of the compressor fails, then the reasons for this may be the following:
- breakdown of the pressure plate when it is incorrectly inserted into the gap;
- the coupling is completely defective, it can “burn out” and the diagnosis of the cause of this is very complicated;
- pulley bearings require replacement.
The electromagnetic fan clutch is used to cool automobile compressors or to maintain a specific engine temperature.
It is also used to maintain temperature during the cold season, especially if the fan is on. It helps to reduce fuel consumption by reducing power on the fan drive.