The applications of hydraulic elevators involve in five to six-floor buildings. The operating of these elevators can be done at speeds up to ft or 61 meters for each minute. All the current hydraulic pumps are designed with a mechanical Y-delta starter otherwise solid state contractor. For the power supply of motor as well as building, solid-state starters are superior. Because the windings stay longer as well as there is no voltage drop across the building power supply.
In Y-delta type starter , the motor can be activated by using two contractors on a decreased speed, after that continues with full speed. Older hydraulic elevators now started up suddenly, transmitting mains power at full-blast right into the electric motor. This sets a lot of damage on the motor, which will make it burn out quicker than motors on Solid-State or Y-Delta Contactor starters.
The pneumatic elevator can be designed with an external cylinder, and the cylinder is a crystal clear self-supporting cylinder.
This cylinder includes modular sections to fit effortlessly into one by one. The top of this tube is designed with steel material that ensures tight air shutting by suction valves as well as inlets.
Pneumatic elevators are very easy to fit, operate as well as maintain when compared with the traditional elevators. These are used in existing homes because of their solid design. The traction elevator or cable driven elevators are the most popular elevators. It consists of steel cables as well as hoisting ropes that run above a pulley which is connected to the motor. This is geared otherwise gearless-traction type elevator. This means, throughout the lifting process it needs extra power for the additional passengers in the car; the rest of the load is managed with the weight of the counter.
When the control system is connected to the lift, then it drives the motors in a frontward way, and sheave turns around to move the car lift upwards and stops in the preferred floor where the car is controlled by the weight of the counter.
Power is only needed to move the unbalanced load between the elevator and the counterweight. An elevator's function is to convert the initial electrical power, which runs the motor, into mechanical power, which can be used by the system.
The elevator is composed of a motor and, most commonly, a worm gear reducer system. A worm gear system is made up of a worm gear, typically called the worm, and a larger round gear, typically called the worm gear. These two gears which have rotational axes perpendicular to each other, not only decrease the rotational speed of the traction pulley 1 , but also change the plane of rotation.
By decreasing the rotation speed, with the use of a gear reducer, we are also increasing the output torque, therefore, having the ability to lift larger objects for a given pulley diameter. A worm gear is chosen over other types of gearing possibilities because of its compactness and its ability to withstand higher shock loads.
It is also easily attached to the motor shaft, sometimes through use of a coupling. The gear reduction ratios typically vary between and The motor component of the elevator machine can be either a DC motor or an AC motor. A DC motor had a good starting torque and ease of speed control. An AC motor is more regularly used because of its ruggedness and simplicity.
A motor is chosen depending on design intent for the elevator. Power required to start the car in motion is equal to the power to overcome static, or stationary friction, and to accelerate the mass from rest to full speed. Considerations that must be included in the choice of an acceptable motor are good speed regulation and good starting torque.
In addition, heating of various electrical components in continuous service should not be excessive. The most common elevator brake is made up of a compressive spring assembly, brake shoes with linings, and a solenoid assembly. The car gradually descends. To stop the car at a lower floor, the control system closes the valve again.
This system is incredibly simple and highly effective, but it does have some drawbacks. In the next section, we'll look at the main disadvantages of using hydraulics. Sign up for our Newsletter! Mobile Newsletter banner close. Mobile Newsletter chat close. Mobile Newsletter chat dots.
Mobile Newsletter chat avatar. The vacuum pump of the elevator generates higher and lower atmospheric pressures above or below the elevator car, which cause to move the elevator upwards and downwards. As shown in the below figure, the car is lifted high by a higher atmospheric pressure below the car and a lowered air pressure above the car. When the valves in the low-pressure chamber allow air into it — this causes to lower the car.
These valves are also involved in controlling the speed of the car in a desired level. But, this type of elevator cannot build enough pressure to push the car to more than 3- 4 storied high building. This is a typical and most popular type of elevator consisting of a few numbers of hoisting ropes or steel cables which run over a pulley connected to an electric motor.
This elevator can be a geared or gearless-traction elevator. In this type of elevator, five to eight wire cables or hoisting cables are attached to the top of the elevator car by wrapping around it on sheaves at one end, and the other end is attached to a counter weight that moves up and down on its guiderails. This counter weight is equal to the weight of the car plus half of the maximum passenger load in that car. This means, during the lifting operation, it needs power for the extra passengers in the car, and, the rest of the weight is balanced by the counter weight.
Whenever the control system attached to the elevator drives the motor in the forward direction, the sheaves also turn around causing to move the car elevator upwards, and then stopping in the desired floor wherein the car is balanced by the counter weight. For the downward movement of the car, reverse happens through a rotating motor via a control mechanism. Some of the elevators use motors with four-quadrant operation to save the energy in regenerative mode.
Due to high speeds and high-rise capabilities, these types of elevators are found in many of the applications of lifts and escalators.
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