System Description; Intended Application Area; General Description; Functions - bürkert 8858 Bedienungsanleitung

5. sysTeM descripTiOn
5.1. intended application area
The modular 2-way and 3-way motor control valve Type 8858 is
suitable for use as an actuator for hot water or coolant circuits in buses,
commercial, amphibious and railway vehicles as well as in machine
tool manufacture.
5.2. general description
Structure
electrical
connection (round
plug in accordance
with DIN 43651,
Hirschmann
manual emergency
actuation (optical
position indicator)
The motor control valve Type 8858 is modular in design and is installed
individually or in blocks. Up to four valves can be combined in one block.
Either a 2-way or 3-way valve can be used. It contains ceramic sealing
elements, the valve body is made of plastic. The electrical rotary actuator
with direct-current voltage motor consists of a maintenance-free,
powerful spur gear drive with magnetic coupling and Hirschmann plug,
an manual override with optical position indicator and one or more
valve modules. In conjunction with the manual override the actuators
10
Motor actuator -
powerful spur
gear drive with
magnetic coupling
and position
feedback
Valve module
english
Type 8858

System Description

have an adjusting angle of approx. 180°. The actuators must not be
operated without a manual override, otherwise the position indicator
may be maladjusted.
5.3.

functions

The actuator rotates a shaft which moves a control disc via a fixed disc
made of oxide ceramic and therefore closes the valve seats A and B
alternately with a sliding transition. Depending on the adjusting angle,
the flow values (2-way), mixing or distribution ratios (3-way) can be
continuously modified. The position is fed back via a potentiometer.