| 摘要 |
PURPOSE:To eliminate such a problem inherent to a conventional counterweight which cannot completely compensate the load to the elevator for a variation so that the load is slipped down upon a start or a stop or the time for acceleration or deceleration increases, and so forth, by completely compensating the load. CONSTITUTION:An elevating device comprises a first motor and a second motor which generates a resistance torque corresponding to a load so as to completely compensate the load. In this condition, since the first motor is enough to generate an accelerating or decelerating torque for elevating the load, it is possible to eliminate a slip down of the load or an increase in the time for acceleration or deceleration caused by installation of a counterweight which increases a fly-wheel effect. The load can be detected by a load cell attached to a pulley, or can be computed from a torque of the motor 1 at a speed of zero. Further, the load is made to be stationary at a predetermined position without a mechanical brake, by controlling the stop position of the second motor even though the load varies. |
