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).
Promotional leaflet detailing the features and function of the McNAB Rotor Hydraulic Shock Absorber.
| Identifier | ExFiles\Box 152\1\ scan0017 | |
| Date | 8th June 1932 guessed | |
| GLIDE WHEN YOU RIDE-MOTOR ON THE ROTOR Rotor Hydraulic Shock Absorber THE MCNAB ROTOR HYDRAULIC SHOCK ABSORBER is a double acting instrument of the low pressure type. This will be noted readily by referring to the illustration, Fig. 1, herewith. Externally the MCNAB ROTOR resembles other well known hydraulic shock absorbers now on the market, but internally the McNAB ROTOR HYDRAULIC SHOCK ABSORBER is entirely different, both in regard to design and function. THE function of the McNAB ROTOR HYDRAULIC SHOCK ABSORBER can be followed readily by referring to the illustrations, Fig. 1 and Fig. 2. Briefly described, in construction this unique instrument consists of a rotor-piston which moves axially in the cylinder only when rotated by means of the splined rotor shaft, which has a sliding fit through the center of the rotor. Axial movement is accomplished by square threads on the outside periphery of the rotor piston, and these engage corresponding threads on the inside periphery of the cylinder wall. FIGURE 1 LABELS: HIGH PRESSURE CHAMBER ROTOR PISTON CYLINDER SLEEVE LOW PRESSURE CHAMBER FILLER PLUG RESERVOIR ARM ADJUSTING VALVE COVER LOCKING RING BASE FIGURE 2 LABELS: RETURN VALVE ROTOR PISTON EQUALIZING PORT TRAPPED AIR SPACE FILLER PLUG OIL LEVEL RESERVOIR ARM ADJUSTING VALVE RESERVOIR REPLENISHING VALVE LOW PRESSURE CHAMBER HIGH PRESSURE CHAMBER CYLINDER SLEEVE OVER-LOAD RELIEF VALVE MINIMUM BY-PASS APERTURE THE MCNAB ROTOR HYDRAULIC SHOCK ABSORBER has a very large piston area, and in service absorbs maximum shocks without building up extremely high hydraulic pressures. The metering channels have a correspondingly large area, which eliminates the possibility of such channels becoming obstructed. The large channel area also disperses frictional fluid heat, and facilitates the regulation of any desired amount of fluid to a fine degree, resulting in smooth, uniform action over varying road conditions. Some of the outstanding features of the McNAB ROTOR HYDRAULIC SHOCK ABSORBER are as follows: ROTOR DATA Inside diameter of Cylinder . . . . . 3 inches Maximum stroke of Rotor Piston . . . . 1 3/8 inches Approximate effective area of Rotor Piston 6.46 sq. inches " amount of fluid in Working Cylinder 8.9 cu. inches " amount of fluid in Reserve Chamber 4.5 cu. inches " total amount of fluid in device 13.4 cu. inches Many other unique structural advantages will be readily noted upon examination and test of this instrument. THE hydraulic fluid passes through suitable orifices incorporated in the rotor-piston body, as well as through the internal channels in the rotor shaft, as shown. Resistance of fluid through these channels is governed by means of one-way ball check valves, and by external needle valve adjustment. Also incorporated in the rotor-piston there is a spring loaded relief valve which takes care of over pressures. IT will be noted readily that the design of the McNAB ROTOR HYDRAULIC SHOCK ABSORBER is such as to permit a large volume displacement of fluid for a small angular movement of the absorber arm. This naturally results in low working pressures under the most severe conditions, and also minimizes temperature changes and insures the maintenance of uniform fluid viscosity. The McNAB ROTOR gives greater stability and confidence in driving. It holds the wheels to the road. | ||