System and method for hydraulic-pneumatic drive with energy storage for elevators
OwnerDan Davidian, Yair Moshe Holland +1inventors
InventorsDan Davidian, Yair Moshe Holland, Avinoam Livni
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Abstract
A power drive for a passenger and/or cargo elevator—or any conveyance-using stored high pressure compressed air as a primary source, producing high pressure hydraulic fluid energy to move a servo-controlled hydraulic motor, mechanically connected to the hoisting mechanism of the elevator, is disclosed. The electric power driving the air compressor is not affected by the load of the elevator (e.g. number of passengers). The electric current is consumed to charge a high pressure air tank. The compressor is operated only when the elevator is in in a parked position, thus electric power consumption level is by no means correlated to the operational mode of the elevator motion.
Claims44
A pneumatic-hydraulic system for driving an elevator cabin, comprising,
- a bi-directional hydraulic motor 24, configured to power motion of the elevator cabin;
- two pneu-hydraulic accumulators 16, 17, configured to feed hydraulic energy to the bi-directional hydraulic motor 24;
- two 3-way, 2-position pressure-compensated flow control valves 34, 35, each disposed between one of the hydraulic actuators 16, 17 and the bi-directional hydraulic motor 24, configured to alternately supply hydraulic fluid to a high-pressure line and a low-pressure return line;
- a pressurized air tank 8 configured to supply pressurized air to the pneu-hydraulic accumulators 16, 17;
- a multistage air compressor 3 configured to charge the pressurized air tank 8;
- and
- a compressor drive motor 2, configured to operate said compressor 3;
- wherein electric power consumption of the system and the cruising speed of the elevator cabin are substantially independent of the load of said cabin, including passengers and cargo riding in said cabin.
Dependencies are inferred from the claim text.