Wound field DC motors 4 (series, shunt or compound) are used in industrial environments for coil feeding reels in the milling/metalforming, crane hoists, motor-driven cable reels, and elevator hoist motors.
Which type of DC motor is used in hoists and cranes?
Which DC motor is generally preferred for cranes and hoists? Explanation: DC series motor is used where high starting torque is required, thus in cranes and hoists DC series motor is used widely. Torque-speed characteristics of DC series motor suits perfectly to these applications. 2.
Which electric motor is used for cranes?
Synchronous motor. For crane travel, trolley travel and boom hoist of traveling crane requires high starting torque and constant speed in operation. Hence slip ring induction motor is preferred. 07․
Which DC motor is used in lift?
AC slip ring or DC compound motors are prefer for lifts. Shunt type commutator motors are preferred in case of single phase installation. The latest lift designs use 3-phase induction motors with variable frequency drive electronic controls.
What is used in crane?
The most important substance used to manufacture cranes is steel. Steel is an alloy of iron and a small amount of carbon. For structures that do not require very high strength, a common form of steel known as carbon steel is used. By definition, carbon steel contains less than 2% of elements other than iron and carbon.
Which DC motor is used in shears and punches?
3. Which DC motor is used in shears and punches? Explanation: Cumulative compound DC motor provides high starting torque which is required at instant of starting in shears and punches. It also provides good speed regulation in order to vary pressure.
What is the speed of dc motor?
DC controls adjust speed by varying the voltage sent to the motor (this differs from AC motor controls which adjust the line frequency to the motor). Typical no load or synchronous speeds for an AC fractional horsepower motor are 1800 or 3600 rpm, and 1000-5000 rpm for DC fractional hp motors.7 мая 2018 г.
How does a DC fan work?
With DC fans, the direct (AC) power source, connects to a transformer which converts the power to DC. The effect is that it decreases the amount of power used by only using a direct current instead of the alternating current.
When the speed of DC motor is increased?
The speed of a dc motor is changed by changing the current in the field or by changing the current in the armature. When the field current is decreased, the field flux is reduced, and the counter emf decreases. This permits more armature current. Therefore, the motor speeds up.
Which starting method is the best method in induction motor?
Starting of an Induction Motor
- Direct on line starter. The direct on line starter method, of an induction motor is simple and economical. …
- Star delta starter. The star delta starter method of starting three phase induction motors is very common and widely used among all the methods. …
- Auto transformer starter.
Why starters are used in DC motor?
Starters are used to protect DC motors from damage that can be caused by very high current and torque during startup. They do this by providing external resistance to the motor, which is connected in series to the motor’s armature winding and restricts the current to an acceptable level.
Which motor is used in pumps?
Which motor is constant speed?
DC shunt motor
What are the types of crane?
There are several different types of mobile cranes, including:
- Carry Deck Crane. …
- Crawler Crane. …
- Floating Crane. …
- Rough Terrain Crane. …
- Truck-mounted Crane. …
- Bulk-handling Crane. …
- Hammerhead Crane. …
- Stacker Crane.
Why does the crane need to rotate?
The crane needs to lift heavy things from different places on the ground. … Why does the crane need to rotate? Rotate means to turn around an axis or centre point. 5.
Who will use the crane with an electromagnet?
These large cranes are used to pick up and move metals containing things such as steel and iron, which is primarily found in recycling plants and junk yards. The electromagnetic cranes work by using a magnetic field that is created by an electric current that can be turned off and on whenever it is necessary.