Introduction
Hydraulic Elevators
Allie Marx, Lizzie Coates, Lilly Jones
May 20th, 2019
May 20th, 2019
Interview/History146 words
Elevators, just like many other advances in technology, became far more common in the mid-1800s during the Industrial Revolution. Many of these elevators were based off the hydraulic system, in which a piston inside a cylinder used pressure from water or oil to raise or lower the elevator car. The main drawback with these lifts was that the buildings containing them needed to have pits below the elevator shaft so that the pistons could draw completely back. The higher the building was, the deeper the pit had to be, making this lift type highly impractical. An alternative model to this used a cable system, in which ropes raised and lower the car by means of a pulley and gear system, this design is much closer to what we use today. In the mid-Nineteenth Century, both of these types of elevators were powered by pressure or steam.
Device Description 100 words
Hydraulic elevators are elevators powered by a piston that travels inside a cylinder. A electric motor pumps hydraulic oil into the cylinder to move the piston. The piston smoothly lifts the elevator cab and electrical valves control the release of the oil for a gentle descent. These hydraulic elevators are used extensively in buildings up to five or six stories high. Sometimes, but rarely, up to 8 stories high. These elevators, which can operate at speeds up to 61 meters (200 ft) per minute, do not use the large overhead hoisting machinery the way geared and gearless traction systems do.
Component Identification 195 words
Reservoir/Tank:
The primary purpose of the tank is to hold the liquid (oil) that raises the elevator, but it also houses the other important components. The size of the tank is dependent upon the number of floors and the components required to move the distance.
Motor/Pump:
The motor which is submerged in hydraulic oil, powers the pump. The pump pushes the oil into the jack to lift the elevator, while gravity does the work coming down. The pump is submersible and attached to the master control valve with a length of pipe called the pump/valve connection pipe. When powered by the motor, the pump pushes the oil through the valve and into the cylinder (jack) or hydraulic jack system.
Valve:
The Master Control valve allows the elevator to run smoothly, efficiently and safely. It controls the amount of liquid in the system, keeps the pressure low when open and high when closed. Setting this valve controls the speed of the elevator when starting and stopping.
Cylinder:
The hydraulic fluid flows into the cylinder which is an underground chamber that the piston can travel u and down in. The piston is an actuator, and converts electrical energy into mechanical energy.
System Operation 164 words
Elevators are a simple concept when thought about. A box, attached to a lifting system. They are a lot more elaborate than that. Especially hydraulic elevators. Hydraulic elevators are provided with more support and used to lift objects with larger weight that a rope elevator may not be able to sustain. A hydraulic elevator, is supported at the base by a cylinder, which requires the buildings to have pits below the elevator shaft so that the pistons could draw completely back. The higher the building was, the deeper the pit had to be. The cylinder also connected to a fluid pumping system that is run by an electric motor. The fluid used in these are normally oil. The fluid pump, pushes the fluid from the tank or reservoir into the cylinder. When the valve opens and pressurized fluid returns back to the reservoir. When the valve is closed the pressurized fluid is forced into the cylinder, raising the piston/cylinder along with the entire elevator.
Schematic
Reflection 95 words
I think hydraulic elevators are a very safe and efficient way of transporting people throughout different floors of a facility. The cylinder support base in this elevator makes it very strong allowing ample weight to be transported safely. However, due to the cylinder in the ground the number of floor level it can reach is limited to 5 to 8. If we cold improve this machine we would try to find a way for the machine to move faster while remaining safe, and also trying to increase the number of floor levels it can reach.
Sources
https://schmelevator.wordpress.com/2016/06/23/the-guts-of-an-elevator-hydraulic-tank/
https://science.howstuffworks.com/transport/engines-equipment/elevator1.htm
https://blog.ansi.org/2016/11/history-of-elevators/#gref
https://science.howstuffworks.com/transport/engines-equipment/elevator1.htm
https://blog.ansi.org/2016/11/history-of-elevators/#gref