Novelty in Transmission Systems
Page 52
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A'unorthodox transmission scheme forms the • subject of patent 'No. 650,672, the patentee being S. A. Andre Citroen, Paris. It is really a modificatic of the once-popular petrol-electric
transmission.. • The drawing shows ,the system in diagrammatic form, in which 1 is the engine and 2 the rear axle. The engine drives a bevel sun-wheel 13) ,which carries the rotor (4) of an ac. alternator The final drive is taken from the planet-carrier 15) so that the action of the whole device is controlled by the behaviour of the other sub-bevel (61— This carries the rotor (1) of an a.c. motor, which is driven by the current generated by the alternator.
By varying the excitation of the generator, the output torque and speed can be infinitely varied within its limits. The field winding of the generator is supplied from a battery, and the excitation adjusted by a variable resistance (8). A feature of the patent is that the generator frequency must be more than 500 cycles per second.
AN ELECTRIC GEARBOX
AGEARBOX giving two forward speeds and a reverse is shown in patent No. 650,873, by Societe Neuilly-sur-Seine, France. _E lectric coupling is used .as ameans 'for-selecnob, with an epicyclic,unit 46 provide second speed and reverse". ... • In the drawing, the input shaft (I) drives a. pair of annular horse-shoesectioned electro-magnets (2 and 3) which are provided, on their. innermost faces, with numeroui serrations. Co-operating with these are an armature (4), which drives the planet-carrier
(5) of the epicyclic unit, and a second armature (6) which drives the sunpinion (7). The action of these armatures is not made very clear; they are both serrated to match their surrounding magnets, and one presumes they function as magnetic clutches. The output shaft is connected with the epicyclic. outer ring (8), whilst the sun pinion can be held stationary by a locking magnet (9).
A42 In operation; when. magnets 2 and 3 are energized, the itin pinion and the planet carrier are rotated in unison; thus giving a direct drive. If magnets 2 and 9 be operative, the sun pinion is held, and the planet carrier driven, which results in the outer ring and its output shaft being driven at a higher, speed.
To obtain a reverse, only magnet 3 is energized and the planet carrier is locked by a sliding dog (10); this causes the outer ring to revolve in the opposite direction.
As the mecl4anically controlled elements are isolated, the planetary gear can, if desired, be run in an oil bath.
TAPERED ROLLER BEARINGS THE rollers in a tapered-roller bear1 ing, when operating under load, align themselves axially, but if the load be one-sided there is a portion of the bearing which is not under load. The rollers in this zone are liable to skew off the axis,' and patent No. 650,817 shows a scheme for preventing this.
• The patentee is Aritish Timken, Ltd., 65, Cheston Road, Aston, Birmingham.
AN AMERICAN ROTARY-VALVE ENGINE
AN interesting design for an engine f-t. having rotary valves is covered in patent No. 650,868, from the HaslerStevens Corporation, Mineola, New York, U.S.A.The objects of the design are simplicity,, coupled with good cooling and lubrication, two features which have given trouble with earlier rotary valves..
The drawing shows i fragmentary vjew of two cylinders of a four-cylindered engine, with a portion of the valve in place overhead. The valve consists of a single shaft (1) running the length of the cylinder-block and fitted with dual flanges (2) at points midway between adjacent cylinders, plus one at each end, Each flange deals with only the inlet or the exhaust, the one shown being the exhaust valve for the two cylinders shown below it.
The combustion chamber (3) of each cylinder projects into the head region,
and has flat sides which make a face-to-face rubbing contact with the rotary flanges. To preserve a gastight seal, spring-loaded bronze rings 14) are lightly pressed against the flanges.
On the upper side of the valve-casing, spring-loaded oiler-pads (5) are pressed against' the flanges, so that a thin film of lubricant is always present at the sealing faces. The oiler pads are made of sintered porous metal, and are kept supplied with oil from the upper inlet bores (6).
As shown, the left-hand cylinder is exhausting through a port (7) into the space between the flanges, whence it leaves via a stationary port (not shown) in the casing. Half-a-turn later, the opposite port (8) has lined up with the right-hand combustion chamber, which is exhausted in turn.
The inlet events are dealt with in a similar manner by the adjacent flanges 9. and 10. Water spaces are shown at 11, the valve flanges beirig cooled during the period they are away from the flame
region. • • A point made in the patent is that as all the sealing forces applied to the various flanges are equal and opposite, no appreciable end-thrust is put on the
-valve as 'a whole. '
'MODIFICATIONS TO CARRY-TYPE EARTH SCRAPERS
D A TE N T No. 650,851 comes from
R. G. Le Tourneau Incorporated, Peoria, Illinois, U.S.A., and deals with improvements in the design of carry'type earth scrapers. Specifically, it is concerned with a means for positively moving the end-gate in either • direction so that it an be used to shift the load.
In the drawing, 1 is the end-gate Which is required to slide along the bottom (2) of the carrying. boWl. To this end, the gate has attached to it a .framework extending to a rear sliding carriage (3). A. wire cable is attached, to the carriage at one end, and to the end gateat the other. Interinediately passes round a. drum (4) carried On the main frame. The cable-drum-is driven by a geared electric motOr (5) and this, by 'suitable switching, an be made to run 'in either direction, and so advance or retract the end-gate.