hydraulic brake system

Abstract

A hydraulic brake system for a passenger transport installation includes actuation equipment, a pump supplying brake fluid to a piston space of the actuation equipment and a motor driving the pump. A control device controls the motor by a frequency inverter whereby the pump supplies brake fluid at a predetermined delivery flow rate (QP). A pressure (pB) is set in the piston space corresponding to an equilibrium in which the delivery flow rate (QP) is equal to a return flow rate (QL). The control device sets the pressure (pB) by the delivery flow rate (QP) of the pump. The passenger transport installation can be a lift, an escalator or a moving walkway having this brake system operated according to the described method for controlling the braking force.

Description

technical field [0001] The invention relates to a braking system for a people conveyor designed as an elevator, rolling ladder or moving walkway; a corresponding people conveyor; and a method for controlling the braking force in such a people conveyor . The invention relates in particular to the field of lift installations. Background technique [0002] A brake safety device for an elevator car is known from EP 0 648 703 A1. In this case, a braking device engaging on the guide rail is provided, wherein the braking force exerted by the braking device on the guide rail is adjusted by the adjusting device. The braking device surrounds the free arm of the guide rail which is provided with the running rails, wherein for each running rail a respective brake plate is provided which is carried by the brake plate holder. Furthermore, at least one of the brake plates can be actuated by means of a brake cylinder, wherein the brake cylinder can be acted upon by a pressure generated i...

AI Technical Summary

Problems solved by technology

[0004] The brake safety device known from EP 0 648 703 A1 for an elevator car has the disadvantage that the actuation of the brake device and the adjustment of the braking force are complicated

Especially the use of pressure accumulators and regulating valves is expensive and complicated

For reliable regulating operation, it is also necessary to regulate and maintain the pressure in the pressure accumulator within the narrowest possible pressure range, which requires frequent switching on and off of motors and pumps as well as precise operation of the switching elements and Correspondingly frequent maintenance work

In addition, in the type of operation in which the brake is closed by means of pressure in the pressure accumulator, the hydraulic system needs to use components that are as leak-free as possible, since otherwise it is used for regular subsequent replenishment of pressure medium or for maintaining the brake pressure for economical operation Excessive energy consumption

However, in the type of operation in which the brake pressure is reduced by means of the pressure of the pressure medium device, the problem arises that the pressure of the pressure medium device must be continuously maintained in order to ensure operational readiness, which creates a high energy demand

Especially due to the large number of components or elements required in hydraulic systems, leakage losses occur, with correspondingly high energy consumption and high maintenance requirements

Images