Secondarily, its thickness allows for wear over the life of the clutch. However, that wear results from a fundamental drawback of diabetics design. Since the armature is thick and massive, it has a high inertia, and all of its originally stationary mass must be “spun up” to match the rapidly rotating pulley and friction disk PRINCIPLE Electric clutches are equipment drive assemblies that contain electrically actuated components for connecting two shafts so that they can either be locked together and spin at the same speed, or decoupled and spin at different speeds.
Engaging the clutch transfers power from an engine to devices such as a transmission and drive wheels. Disengaging the clutch stops the power transfer, but allows the engine to continue turning. Electric clutches permit faster cycling times than pneumatic or hydraulic clutches, but do not provide the same range of torque. They are best suited for automatic machinery that Aryanism control commands as electric signals rather than as pedal or lever motions.
Electric clutches are also useful in applications where the clutch is so far removed from the control point that mechanical connections or pneumatic or hydraulic piping would be difficult to maintain or prohibitively expensive. Specifications for electric clutches include torque rating, power, rotational speed, and operating voltage. Sputtering clutches require power to engage. Supersaturated clutches require power to disengage. A variety of engagement methods are available. Noncombatant clutches uses methods such as magnetic fields and eddy currents. Friction clutches generate friction between contact surfaces.
Wrap spring clutches transmit torque from the input to the output through a wrapped spring that uncoils to disengage the clutch. Oil shear clutches achieve drive engagement through the viscous shear of transmission fluid between the clutch plates. Sprats, steel wheels that tip in one direction to wedge between inner and outer races, are clutches that can often transmit more torque than other slip or overrunning devices. Ball detent clutches feature a slip mechanism in which, upon overload, dated balls are dislodged and overcome springs or air pressure engagement.
Similarly, pawl clutches overcome spring or air pressure engagement and rotate out of their detent. With roller detent clutches, rollers that are held in place by springs wedge between the inner and outer races to engage the clutch. Selecting electric clutches requires an analysis of measurements, shaft configurations, drive and load connections, and special features. Measurements include diameter, the jurisdictional width of the assembly; length, the dimension along the axis of rotation; and weight.
Shaft configurations can be inline along the axis of the load, parallel but offset from the axis, or perpendicular (right angle) to the axis. Drive and load connections for electric clutches use shafts that attach to bores or flanges. With some drive shafts that attach to bores, the output is a drive component such as a pulley, gear, or sprocket. Often, these types of electric clutches are designed to accept several different drive components. Special features for electric clutches include feedback, zero backlash, and washbowl capability.
Industrial or generalship’s electric clutches are designed for a wide variety of power transmission applications. Specialized devices are available for aerospace, automotive, heavy transport, marine, military, and afford applications. Some electric clutches are designed for use with web tension control, automation, or robotics systems. Other devices are designed for use with conveyor drives and pump motor drives. Power take Off clutches (OPT) are typically used with heavy equipment such as dump trucks, snowplows, and tractors.
ELECTROMAGNETIC CLUTCH WORKING Electromagnetic clutches operate electrically, but transmit torque mechanically. This is why they used to be referred to as electromechanical clutches. Over the years ME became known as electromagnetic versus electro mechanical, referring more about their actuation method versus physical operation. Since the clutches started becoming popular over sixty years ago, the variety Of applications and clutch designs has increased dramatically, but the basic operation remains the same-Singleness clutches make up approximately 90% of all electromagnetic clutch sales.
The clutch operates (as far as my limited understanding goes) by passing a current through some kind of magnetic powder (maybe just iron filings? Anyone know what this is? ) which fills the gap been. En the driving (engines) and driven (gearbox/wheels side) plates. When the engine is at idle, no (or very little) current is passed through the powder so the engine spins without transferring force to the driven side. ENGAGEMENT: A horseshoe magnet has a north and south pole. If a piece of carbon steel contacts both poles, a magnetic circuit is created.
In an electromagnetic clutch, the north and south pole is created by a coil shell and a wound coil. In a clutch when power is applied, a magnetic field is created in the coil . This field (flux) overcomes an air gap between the clutch rotor and the armature This magnetic attraction, pulls the armature in contact with the rotor face. The frictional contact, which is being controlled by the strength of the magnetic field, is what causes the rotational motion to start. The torque comes from the magnetic attraction, of the coil and the friction be;En the steel of the armature and the steel of the clutch rotor.
For many industrial clutches, friction material is used between the poles. The material is mainly used to help decrease the wear rate, but different types of material can also be used to change the coefficient of friction (torque for special applications). For example, if the clutch is required to have an extended time to speed or slip time, a low coefficient friction material can be used and if a clutch is required to have a slightly higher torque (mostly for low RPM applications), a high coefficient friction material can be used.
This is the engagement operation of the “ELECTROMAGNETIC CLUTCH”. DISENGAGEMENT: When current/voltage is removed from the clutch, the armature is free to turn with the shaft. In most designs, springs hold the armature away from the rotor surface when power is released, creating a small air gap. At slow speeds, the engine speed is low o that the current to the coils in flywheel is low. Because of that there is not much engagement. Therefore only low torque can be transmitted. That is, there is slip between flywheel and clutch plate.
To compensate this, at slow speeds, the operation of accelerator pedal provides a flow of current to coils from battery . In Multiple disk clutches operate via an electrical actuation but transmit torque mechanically. When voltage /current is applied to the clutch coil, the coil becomes an electromagnet and produces magnetic lines of flux. These lines of flux are transferred through the small air gap between the field and the rotor. The rotor portion of the clutch becomes magnetized and sets up a magnetic loop, which attracts both the armature and friction disks.
The attraction of the armature compresses (squeezes) the friction disks, transferring the torque from the in inner driver to the out disks. The output disks are connected to a gear, coupling, or pulley via drive cup. The clutch slips until the input and output RPM are matched. This happens relatively quickly typically (. 2 2 sec). CONSTRUCTIONAL DETAILS The electromagnetic clutch consists a stator body (fly/heel) contains the field coil, which is a copper coil cast in synthetic eosin. The clutch is activated by applying a direct current to the field coil.
Cite this Assignment about Electromagnetic Clutches
Assignment about Electromagnetic Clutches. (2018, May 30). Retrieved from https://graduateway.com/a-description-of-electromagnetic-clutches/