Walschaerts valve gear

The Heusinger control or Walschaert control is a steam machine control locomotives.

History and distribution

Edmund Heusinger von Waldegg invented the control in 1849. However, the Belgians Egide Walschaerts had invented so the same principle already in 1844 independently of him five years earlier, which is why this control is called outside the German-speaking world as Walschaert control.

The vast majority of European steam locomotives equipped with this control. Further developments of the Heusinger control the angle lever control and the spread in the United States Baker - control.

Operation

Instead of several eccentric to a crank pin offset from the crank is mounted on the driving axle. From there, a swing bar goes to the bottom of a slide with a fixed pivot point. This transfers the motion to the slide pusher bar. The direction and the stroke of the valve push rod can be adjusted by the position of the sliding block; is the sliding block in the middle ( ie in the axis of rotation of the link ), the bar does not move; The more the block is displaced upwards or downwards, the more the valve push rod is moved in the corresponding direction.

The Voreilhebel is moved to the lower end of a rod ( steering rod ) from the cross-head, the upper end of the valve push rod. In between the Voreilhebel is connected to the slider. Combined from the phase-shifted motions of the slider rod and the handle bar arise as direction and stroke of the slide.

Since the direction of movement and the stroke of the valve push rod by means of the control rod can be adjusted from the driver's cab, so the working direction and degree of filling of the steam cylinder can be controlled.