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).
From a publication detailing various methods of automotive chassis lubrication from the early 20th century.
| Identifier | ExFiles\Box 76\4\ scan0143 | |
| Date | 28th February 1918 | |
| AUTOMOTIVE INDUSTRIES THE AUTOMOBILE February 28, 1918 Page 443 evidence secured. The most notable instance of passenger car chassis lubrication with oil was the outcome of extensive garage experience. In the past 3 years so-called oil-less bushings of various composition have come into considerable use for spring bolts, pedal shafts, brake shafts, etc. Some are made of hardwood impregnated with lubricant, some of brass or bronze with inserts of graphite or other lubricant, some of a lubricant impregnated woven material, resembling brake lining, fitted inside a steel shell which holds it in shape. When properly selected and applied they have in most instances been quite serviceable, and showed a notable improvement at points which have heretofore not had much, if any, lubrication, because they have been difficult to reach. The writer considers these bushings in the light of a palliative and not a solution of the problem of lubricating such points, because they contain a very limited amount of lubricant which must suffice for the life of the bushing. These oil-less bushings are well adapted to eyes in levers and rods which usually get no lubrication at all, such as the eyes in clutch throw-out levers, brake levers, etc. A better way of lubricating these points, however, is to arrange that the drip or seepage from other bearings is led to them. The oil lubrication of many chassis parts has been adopted by quite a number of well-known builders shows that experience is being heeded, and attempts to improve reliability are being made. As reliability is the large word in all automotive design we can expect further improvement in details for the use of oil. This brings us to the consideration of the methods to be used in handling oil as a chassis lubricant. There are two general methods: 1—Direct feed. 2—Wick feed. The direct feed method can be divided into two systems: a—The individual point; b—The central supply. Individual Feed System The individual point system consists of small oil cups applied in the place of grease cups, with the necessary modifications to insure gravity feed. This is crude and open to the objections that dirt can enter the bearing with the oil, that but a small amount of oil is carried at each point, and that the oil is quickly drawn from the cup. This means that frequent attention (almost daily) is necessary, oil is wasted, and it sometimes drips and makes the neighboring parts somewhat unsightly. Various types of oil cups have been used to minimize the outflow of the oil they contain. Those most popular are small brass cups, 1/8 in. pipe tap size, with a snap lid{A. J. Lidsey}, and which contain a thimbleful of wool or cotton waste held in by a wire screen. Any such cup, however, is objectionable because it can be, and often is, easily knocked off, leaving the shank jammed in the tapped hole. They are so small that the loss of one sometimes goes unnoticed for some time, and then replacement is delayed, because the machine seems to run all right without it. In this system the brackets for pedal shafts, rocker shafts, etc., are simply drilled and countersunk to receive a drop or so of oil from a squirt can when the spirit moves the man in charge to be over-curious and discover them. The only instance of the central supply system is that embodied in the Fergus car. In this chassis oil is led by pipes to four central supply points—the fulcrum pins of the cantilever springs—and from these is distributed to springs, spring bolts, steering connections and levers. Only a few of these have been placed on the market, and the system has not been adapted to any other car, so far as the writer is aware. This is possibly due to the fact that it does not lend itself readily to our more or less standardized chassis design. The oil, being supplied by a pressure from the engine, is liable to a considerable loss due to leak or breakage, with consequent danger of exhausting the supply in the engine and the nuisance of a considerable flood of oil. The system, however, courts development. [Captions Page 443] Above—Front spring front bracket of Class B war truck, showing chain-held filler plug and pipe for wick. Below—Rear spring rear shackle on Class B war truck, showing separate feeds for spring bolt and shackle bushing Wick oiling of brake linkage shafts on Class B war truck Fergus cantilever spring enclosed in a leather boot and provided with oil channels for a regular system of oil circulation Page 444 AUTOMOTIVE INDUSTRIES THE AUTOMOBILE February 28, 1918 In 1915 the writer conceived the idea of improving the chassis lubrication by a magazine system using oil carried so as to require a minimum of attention, both as to the number of points and the number of fillings; which would feed clean oil as needed to the bearing surfaces; and which would not be liable to damage under careless handling. The first opportunity for carrying this out came in 1916, when it was incorporated in the design of the Fageol line of motor trucks. Magazine System for Oiling Chassis Parts The main feature of this magazine system was a series of hollow brackets and shackles for the spring bolts and rocker shafts. These brackets held oil which was wick fed to the various bearing surfaces by capillary attraction, there being no direct gravity feed. Felt wicks about 1/4 in. in diameter, dipping to the bottom of the pockets, carried the oil to the top of the pockets and then through drilled passages to the bearing surfaces. In some cases after reaching the initial bearing the oil flowed to another nearby and then to the springs, which were kept from rusting and from stiffening. The rear spring shackles are hollow and contain oil fed by wicks to the spring bolts and to the shackle bar. The pins of the front shackle are fed in series from the bracket above. The knuckle pins and the steering connections on the front axle were designed to take large steel oil cups with wick feed. The cored brackets hold oil enough to last from 6 weeks to 2 months; the supply in the cups will last about half as long. The brackets are closed by large pipe plugs, the cups by swivel caps with registering holes near the wall of cups. The scheme was further developed in the Class B war truck, where the brake levers and brackets, shackles and shackle brackets are cored and the oil is wick-fed to the bearing surfaces. The filling holes are closed with large wing plugs permanently attached by chains to prevent loss. The knuckle pins in the front axle are oil lubricated by wicks leading oil from wells at the bottom of the pins up through the pins themselves, and fed to the bushings and thrust washers. The method of lubrication has many advantages. It requires almost no attention—once a week for the cups and once a month for the brackets at the most. There are but very few oil cups, they are not exposed to damage, and the cups are large (1/4 in. or 3/8 in. pipe tap) and strong. They are well protected, as they are only used on steering connections, rear axle brake camshafts, steering gear, pedal shafts, etc., which points are not exposed to collision. Dirt cannot enter bearings with Feeding Oil by Capillary Attraction The wick feed method can also be divided into two systems at present, viz.—the individual point and the magazine feed, which latter is really a development of the former. The individual point system was first used by the writer in 1913 (on the truck to which reference has been made) and consisted of small wick oilers applied in place of grease cups, certain of the chassis parts being adapted to lend themselves to this kind of lubrication. The results obtained were so satisfactory that the writer became a firm advocate of oil for chassis lubrication. From 1914 to the present we have seen more and more use made of this system, which is quite effective. The wicks feed oil slowly but speedily when the machine is in motion, and the oil supply is conserved so as to last much longer than with the direct feed cups. The large number of points to be oiled, however, make it likely that some will be overlooked; and the small wick oilers are open to the same objections as the direct feed oilers—they get damaged or lost and are not often replaced promptly. [Captions Page 444] Wick lubrication of knuckle pin bearings on Class B war truck Myers’ system of wick lubrication for universal joints Above—Two types of oil-less bushings (O & S and Bound Brook). On right—Bowen wick oiler Winkley oilers used on Ford spring bolts and front axle | ||