Elevator..Presented by.. 1. Bidrohi Bhattacharya2. Samit Kumar Bhoumik3. Sankha Majumdar

Types of ElevatorsHydraulic Elevator

Traction Elevator

Traction ElevatorsThe Cabin is fastened by a rope system driven by the traction machine. The Cabin is balanced by the counterweight. As the Cabin goes up the counter weight goes down and vice versa.The counter weight is much heavier than empty cabin.

Traction Elevator..The purpose of the counter weight system is to keep the total system energy constant.The SHEAVE over which the rope moves is driven by the Geared or Gearless Motor.The Motor has to overcome only the frictional force as the most of the weight is balanced by the counter weight.

Traction Elevator..The cabin and the counter weight are supported against horizontal forward or backward movement by a pair of rails on both sides.The balancing makes the lift so energy efficient that it may even be drive by battery supply.

Types of Traction Elevators( Depending upon position of Machine Room)

Machine Room Elevator i.e. has an external room to accommodate the traction machine ( normally above the lift shaft).Machine Room Less Elevator i.e. no external room is needed. In General Permanent Magnet Machine is used here.

Home Elevator.It may be a traction elevator or hydraulic elevator but operates on single phase supply.It is capable of operating in small rise and for small capacity.

Hydraulic ElevatorHere the cabin is connected to a hydraulic ram which moves the cabin.The hydraulic ram consists of a fluid driven piston mounted inside a cylinder.The cylinder is powered by the fluid controlled by a pump, valve. The fluid is a typical one called the Hydraulic Elevator fluid.

Hydraulic Elevator.The fluid from the tank is pumped by the pump mechanism and the valve opens. So the pressurized fluid thrusts the cylinder up. At the destination the valve closes, keeps the pressure and the cabin stops.During descending of cabin the valve opens and the fluid comes back to the tank. So no pumping action is needed as the cabin descends.

Hydraulic Elevator..The valve is controlled by the solenoid switch.The controller controls the solenoid switches.The system as it appears is incredibly simple but do have some draw backs.

Advantages & Disadvantages Advantages:Low initial costSpace and pressure efficientSmooth operation.

Fluid is compressible.Disadvantages:High running costRise cannot be beyond 25 meters.High speed version is not possible.Leakage and heat production makes it tougher to maintain.