About Hydraulic Elevators
Description: This application will accommodate front openings as well as front and rear opening configurations. This is the traditional hydraulic design that has been used for decades. The hydraulic cylinder (Jack) is in the ground directly under the Car platform. This arrangement can accommodate high low capacity cars for both passenger and freight applications.
Advantages: This type is generally the lowest material cost application if the Jack is a single stage unit. This Car Type is generally the simplest to design and install.
Disadvantages: A single stage cylinder must go down into the ground roughly the same distance as the desired travel. Possible oil contamination in the ground is the most detrimental aspect of this car type. Precautions can be taken in the form of encapsulating the Cylinder within PVC pipe. High seismic activity areas will experience the greatest risk of underground cylinder leakage. In some geographic areas, the cost of drilling a jack hole can be very expensive, if it is possible at all.
Description: This arrangement allows for a 1 to 2 roped ratio. That means that for every 1 foot of movement by the Piston, the Car moves 2 feet. Here, the Jacks along with all the associated Rope equipment are located on each side of the Car. As was the case with the Twin Jack Hole-less, maximum structural strength is attained with this arrangement and high capacity Cars can be accommodated. This design accommodates both passenger and freight elevator applications.
Advantages: No Jack holes are required even though the travel can be as great as 100 feet. Without any Jacks in the ground, the risk of oil contamination in the ground is eliminated. No extensive pit or overhead is required. Because of the 1 to 2 roped arrangement, the Jack’s length is roughly equivalent to half of the Travel. The jack also moves at one half the speed of the car. High capacity Cars can be accommodated.
Disadvantages: Additional hoist way width may be required to accommodate the Jack and Rope equipment installed on both sides of the Car. The installation time is greater than that of hole type applications because of the additional equipment (Ropes, Safeties, Governor, and Sling).