METHOD AND APPARATUS FOR REDUCING DRIVE POWER OF A HYDRAULICALLY ACTUATED LIFT

The invention relates to a method and an arrangement for reducing the driving power for a hydraulic elevator in which an energy-saving drive is realised by an advantageous combination of various devices. The elevator car (1) is suspended in the shaft (7) with a rope deflection known per se in the ratio of 4:2 and is connected to a hydraulic piston/cylinder unit (10). A counterweight system in the ratio of 2:1 is arranged at the head end (16) of the piston/cylinder unit (10) so that the requisite pressure force at the piston can be reduced. The counterweight (23) is designed in such a way that the weight of the car and the load expected to occur most frequently in the car are balanced. The cylinder (11) of the piston/cylinder unit (10) is acted upon by the pump for both the ascending travel and the descending travel of the elevator car (1), in the course of which a differential circulation of the fluid flows takes place for the ascending travel, as a result of which a smaller fluid volume can be used for the dimensioning of the pump.