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).
Article from 'The Motor' magazine discussing the Lentz hydraulic transmission gear.
| Identifier | ExFiles\Box 136\4\ scan0004 | |
| Date | 14th November 1911 | |
| The Motor 736 14th November, 1911. LENTZ TRANSMISSION GEAR.—Contd. transmission (the word “hydraulic” is used in its colloquial and broad sense to include other fluids in addition to water) we have never known any laboratory tests which gave figures as high as the one claimed. Be it said, however, that with an efficiency considerably less than this, there would still be a large field for serious consideration for the gear, so that perhaps we may leave that point out of consideration for the time being and consider other features. One of the first things which struck us adversely was the lack of balance in the pistons, etc., whilst rotating, but it is claimed that this is of so small moment as to be negligible, and that if extreme accuracy were desirable, a balance could be obtained: a sound and reasonable reply. The next point which we raised was the fact that the vanes, both of the pump and the differential pistons, when at their maximum eccentricity, and, therefore, subject to the greatest pressure, are at the same time supported by their minimum bearing face surface. This struck us as being rather an unfortunate state of affairs; but the reply to the criticism was truly Teutonic in its simplicity and unanswerableness. The reply to the criticism is to the effect that the minimum bearing face surface at the moment referred to is arranged to be sufficient for the maximum stress, and that all extra bearing surface above the minimum is purely extra support, which is not needed, but is utilized, as it is simpler to use it than to dispose of it otherwise. With regard to simplicity, we are certainly inclined to agree that, although the mechanism itself is not absolutely simple, nevertheless, in the aggregate, it is certainly simple in regard to the number of parts which it replaces, as, from the ordinary chassis, one deletes the clutch mechanism, universal joint connecting to the gearbox, gearbox, gate control, etc., differential brake at the back of the gearbox, torque tubes, spherical housings, etc., bevel gears in the back axle (or worm, as the case may be) and differential gear. Obviously, therefore, there is also a considerable reduction in the number of parts, and, finally, balancing up the points, and bearing in mind the fact that the name of the inventor is Dr. Lentz, we certainly consider the proposition deserving of further investigation, more especially as we now hear that preparations are being made for manufacturing it in England, so as to conform with the new patent regulations. We have not, as yet, had an opportunity of trying a car fitted with this transmission gear, but we are intending to do so in the near future, and then we shall have a few subsidiary details to record as to the practical operation of what is certainly a very clever production. The finish and work embodied in the transmission gear and parts thereof shown at the Exhibition were quite beyond reproach, and the arrangement of the distributor valve mechanism, etc., would appeal to the judgment of anyone versed in mechanics. The address of the inventor is: Dr. Hugo Lentz, Berlin. Grunewald, Hubertusallee 14. [Image Captions] One of the differential-butment pistons which transmit the drive to the road wheels through the medium of cardan shafts. The position and method of operation of the four vanes is clearly indicated. The cover plate with the cam track cut in its face, through the medium of which the vanes are moved in and out as required. This cam track of course, corresponds with a similar one for the inside rollers of the vanes to run in. A front view of a Prince Henry type of Vauxhall car. [Other Text] B24 V-1919 (on license plate) | ||