However, their horsepower ratings are less than wound-field DC motors. Hence, they are used for continuous duty applications. PMDC motors are more compact with consistent speed-torque response, having better thermal characteristics than wound field DC motors. Permanent Magnet DC motors and wound field DC motors are two types of DC motors in vogue. The DC motors with permanent magnets use strong magnets for production of magnetic field. The hydraulic lift pump of forklift also operates on an electric battery, using a lift jack and with a system of chains and rollers. These batteries also add counter weights for providing counterbalancing forces against the lifted load, adding to the balance of the forklift. They usually utilize lead acid batteries of 10-75KWh capacity for traction, steering and lifting power. Any number of poles is possible for electric forklift batteries, as it is dependent on the size of the motor and its application.Īll indoor forklifts use electric motors operating on 12, 24, 36, or 48 VDC batteries. ![]() More than two poles facilitate continuous spinning of the motor uninterruptedly as compared to two pole battery. The battery of an electric motor used in forklift trucks usually has more than two poles. Brushes are simply metal springs or carbon made, which make contact with the contact points of the commutator and pass current. They are also responsible for altering the polarity, meaning the changing of direction of flow of electrons in the armature, which results in changing its polarity as an electromagnet. The commutator and the brushes work together to provide current to the armature. The time of changing of polarity of the electromagnet is responsible for the uninterrupted spinning of electric motor. Now, if at this precise time, the polarity of electro magnet changes, changing its North Pole to the South Pole, it will again, be repulsed and the motion will continue. Their internal repulsion will cause the electromagnet to spin, making its north pole come in front of the south of the permanent magnet. This happens when similar poles of electromagnet and field magnet face each other. ![]() The electromagnet is made to change its polarities successively, which means that its north and South Poles keeps changing in a way that the electric motor continues to spin without interruption. Provision of field magnet is made in the housing of the motor and various methods are used for several types of electric motors. ![]() Ends of wires are soldered to terminals and the terminals are wired to commutator plates. The armature is electromagnetic, usually comprising of a few metal plates stacked together with metallic wires (generally copper) coiled around these plates. The axle of an electric motor holds the armature and commutator. Therefore, most electric motors use a permanent magnet for this purpose. Field magnet can also be an electric magnet, but will be power expensive. The armature is an electromagnet suspended in the magnetic field created by a permanent magnet, the field magnet. The inherent quality of attraction and repulsion of similar and opposite poles of a magnet serves to create rotational motion in an electric motor. Essentially, an electric motor is all about magnets and magnetic fields. ![]() However, complicated electronic circuitry is involved for getting an AC output from DC batteries.Īn electric motor schematically consists of an armature or rotor, a commutator, brushes, axle, field magnet and a DC power supply. Whereas, the AC driven motors did not need carbon sliding contacts and hence are virtually maintenance free. The DC battery motors necessitated the use of carbon sliding contacts for flow of current, which require continuous maintenance and servicing. However, modern technology uses power electronics to exercise control over electric motors. Motors were controlled by adding resistors in their circuitry. In the initial phases of their development, electric forklift trucks only used direct current motors, since the lead acid accumulators utilized at the time only supplied DC. They use electric batteries as a power source, which needs to be charged separately or during drive with built in generators.Įlectrically operated forklifts are powered by alternating current (AC) or direct current (DC) motors. They are ideal for the environments where it is important to keep exhaust emissions at a bare minimum and avoid loud engine noises.Įlectrical forklifts, in recent years, have made their mark quite prominently on the horizon of material handling equipment. Forklift electrical motors power a wide range of Electric Forklift trucks, which are best utilized for indoor environments.
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