From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Brief description of the parts and action of a double-acting plunger type hydraulic damper.
| Identifier | ExFiles\Box 67a\1\ scan0185 | |
| Date | 29th April 1926 guessed | |
| contd :- -4- HYDRAULIC DAMPERS. The following is a brief description of the parts and the action of this damper. At present we have only been able to conduct a few simple tests on the car but are preparing to carry out further experiments with the view to finding out more about the action of these dampers. The damper is of the double acting plunger type working in an oil cylinder. The plunger is attached to the frame and the cylinder has the same vertical motion as the stub axle. The fluid resistance offered to the up and down motion of the road wheel relative to the body is considerably more in the down, or rebound, direction than the other direction. We have made a simple test and estimate this to be eight times greater. These figures are very approximate but we hope to obtain more accurate results later. The attached prints show the arrangement of this damper and a diagrammatic sketch is also supplied in order to point out some of the more important details. UPWARD DEFLECTION OF ROAD WHEELS. Upward deflection of the road wheel in relation with frame decreases the volume in the cylinder 'B'. Fluid resistance results from the oil passing through the twelve .171" dia. holes and past the light disc valve in the piston into the upper cyl. 'A'. The stem of the plunger takes up some of the space in the upper cylinder consequently a volume of oil equivalent to the displacement of the stem passes from cylinder 'B' through a .075" dia. hole in the end of the plunger up the oil duct contd :- | ||