OIL ECONOMY REAR AXLES IN the issue of " The
Page 45
If you've noticed an error in this article please click here to report it so we can fix it.
Commercial Motor" dated I November 7, Mr. Brewster, of J. Brewster and Co., Newcastle-upon-Tyne, raised some queries regarding the design of rear axles relative to oil consumption, and we feel that certain statements made in his letter are not altogether accurate He compares the oil-retaining characteristics of rear axles of 1930 manufacture with those of the present day, and suggests that much is to be desired in the modern axle In the first place, in 1930, rear axles were of the semi-floating type, and great difficulty was experienced in keeping oil out of the brake drums, necessitating the use of oil catchers attached to the inside of the hubs to collect leakage and eject it. to the outside of the hub, and vehicles could frequently be seen with the rear wheels covered with oil. The wormshaft gland at that date was of the adjustable-packing type, which had the disadvantage of suffering severely from heat and burning were it overtightened.
With present-day axles of the fully floating type, using bellow glands on the inside of the hubs., trouble with leakage of oil into the brake drums is, in our experience, practically unknown, and adequate measures are provided so that over-lubrication lifts the gland off its seat and surplus lubricant is then ejected outside the brake drum and not over the road Wheels. The same type of sealing gland is also used on the worenshaft, and il is our experience, over many years' use, that this type is superior to the adjustable-packing type.
The use of seals along the axle shaft invariably results in grooving; we have eliminated these seals to reduce maintenance, and favour power-lubricating the hub with grease, which packs the hub and penetrates the space between the shaft and the bore of the axle for only a few inches before forcing the hub gland off its seat, surplus lubricant then finding its way on to the road.
Some operators of our vehicles have dispensed with the greasing operation for the hub and rely entirely on the axle oil for lubricating the hub bearings and gland facing This system is known to be successful and lubricant does not, as stated, pass the hub oil seals, which are of large sealing area with a contact-loading in position of 40-50 lb.
It is suggested that hub seals should be of the smallest diameter, but in practice any such scheme entails the oil seal being of the lipped rubber type, carried in and driven by the hub, and difficulty is likely to be experienced as the result of damaging the seal when removing the hub should the inner bearing be tight on the axle case. The surface speed of a sealing ring as suggested is, at 30 m.p.h., 6.5 ft./sec. on the outer bearing and 4.3 felsee..on the tube, a difference of only 2.2 ft.! sec., and it is our opinion that the large sealing area we obtain is far more effective.
With regard to the final paragraph of Mr Brewster's letter, we are in complete agreement that if loss can be eliminated, the figure of oil consumption of one pint per 10,000 miles is reasonable, and this is a figure we try to attain.
THE ASSOCIATED EQUIPMENT CO., LTD.
Southall.
'F THEletter from Mr. Brewster in your issue dated HE 7 is of particular interest to me. I agree with him that the rear hub oil seals on the vehicles of some leading manufacturers remain a weak point in otherwise excellent designs.
Mr. Brewster refers to the head of oil against the seal; to the static head must be added the head due to centrifugal action resulting from the rotation of the hub.
Each additional inch of seal-track diameter results in another 3.14 ins, of seal-face length to maintain oiltight.
The loss of oil is a serious matter; far more serious, however, is the contamination of the brake shoes that often follows N. C. KEW. London, W.13 AN APPRECIATION OF THE LATE SIR ARTHUR STANLEY AY I pay -a tribute to Sir Arthur Stanley's long, vl voluntary services to both private and commercial motoring? His interest was aroused when, in December, 1900, he accompanied his father, who, as president of the local branch of the Self-propelled Traffic Association, was in the chair at St. George's Hall to bear M. Georges Forestier, Engineer-in-chief of the French Government's Department of Bridges and Highways, deliver a memorable address. Stanley's interest in motoring, thus initiated, never flagged. He took a prominent part in arrangements for the third open competitive trials for heavy motors, which were based upon Liverpool in 1901. In course of the various trials functions he was proposed as a member of the Automobile Club of Great Britain and Ireland (as the R.A.0 was then styled), to become, later, its chairman for so many years.
From 1901 to 1904 he actively and financially supported pioneer motor road transport in undertakings which sought to aid industry and shipping in the Liverpool-Blackburn-Manchester triangle, and cooperated with the late Mr. Walter Long, then M.P for the West Derby Division, in securing the increase from three to five tons in the unladen weight of commercial motors, without which advance, the affected passenger and goods sections of the industry must have collapsed.
Amongst Stanley's other noteworthy and, perhaps, most-widely known services to automobilisrn were, without question, those rendered as chairman of the R.A.C. He never spared himself in defending the cause of motoring, of fostering its ,full development in the national interest and internationally, in furthering the provision of road touring services, which are now so generally valued, and in maintaining the high standard of serieiee known to exist in the Pall Mall Clubhouse and at the Woodcote Park Country Club. His support for road improvement was persistent, his labours unremitting.
I join with many in treasuring the memory of so good a friend of motoring in all its branches and, in my case, a close personal friend. He was one of the "old school" in the best sense of those words.
Shere. E. S. SHRAPNELL-SMITII, C.B.E..