A Compact Four speed Gearbox
Page 68
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PATENT No. 340,140, by the Daimler Co., Ltd., Coventry, A. E. Bush and E. 1). Frost, describes a four-speed gearbox which is claimed to be less noisy than one constructed on the usual lines on account of its short and stiff shafts and because herring-bone or helical gears can be used for an indirect third speed.
The driving shaft is 1 and the driven 2, the latter having an enlarged bell-shaped portion which extends over ,the. driving shaft and is supported by a roller bearing (6). The sleeve (7) is keyed.to the bell at 4 and is provided with dogs at its right-hand end. The ben formation of 2 is slotted where the ring (14) slides on it, 14 having internally extending projections which enable it to engage with either the sleeve (7) or the dogs (12) on the loosely mounted constant-mesh pinion (9).
Two gears (18 and 10) are splined to the bell of the driven shaft and can engage with either of the gears (20 or 21) on the layshaft.
The different gears are obtained as follow :—First gear, 21 engages with 10, 14 engages with 12; second gear, 20 engages with 18, 14 ,engages with 12; third (indirect) gear, 14 slides to right and its dogs engage with the _dogs (12) of the loosely mounted pinion (9) ; top • gear; 14-slides to left and its dogs (16) engage With those (s) on the sleeve
• --(7). The ,sectional view is taken on the line AA.
An 'Airless-injection System.
THE name of K. J. E. Ilesselman, of Saltsjo-Storiingen, near Stockholm, Sweden, appears in patent No. 340,069, which relates to improvements on patent No. 312,376.
A cylindrical chamber is provided, into which the airless injection of the fuel takes place, and which is provided with a sparking plug (8).
A tangential passage (5) communicates with the cylinder, and the cora pressed air is said to swirl in the direction of the arrow: A variable-stroke pump is employed to control the period of delivery. The fuel is sprayed against a shield (10). Two forms of chamber are shown.
A Variable-speed Gear.
IN patent No. 338,929, Joseph Maine,
10, Grosvenor Gardens, London, S.W.1, describes an automatic variable speed gear in which a fluid medium is driven by centrifugal-force on to a reactionary secondary hydraulic -element It is claimed that,
by this means,. the torque transmitted te the driven ele ment may be varied while the dPiving element runs at a constant speed.
The part (B) is driven by the engine, whilst K is the part which it is claimed can vary, not only in its speed, but in respect of its torque.
B carries with it a casing (A) and an internal gear (0), also the *sleeve (Al) and the casing (As), to which are attached the two frietion discs (11 and P).
The shaft (K) is keyed to the disc (M) which acts as a carrier for the planetary Pinion (D), and extends to the right, carrying with it the secondary hydraulic element (H) and being carried beyond it to drive the axle vehicle.
The sleeve (F) carries a sun wheel (E) at one end and the primary hydraulic element (G) at the other end. The member (I) is described as having a teroidal form and embodying diffuser vanes (3), both of which are fixed to the casing (A2). The construction of the vanes (J) and their relation to the casing (A2) is not very clear, as a line appears to be missing in the drawing, which we reproduce in the right-hand column.
A friction clutch is provided where Q is gripped between It and P. the result of which would be to drive the whole as a solid mass, this constituting top gear. The action of the hydraulic part of the device would appear to be as follows:— When power is applied to the casing (A) and all the parts connected with it, and resistance is applied to the shaft (X), the pinion (E) would rotate in a reverse direction to A unless some force , were applied to check it, hold it still, or drive it in the same direction as that in
which. .A is revolving. * *
This force can come only from the resistance or torque 'derived from the fluid actiiig Upon the secondary hydraulic element •(H) to drive it forward, or acting upon the primary. element (0) to cheek it, hold it, or _drive it forward.
In connection with the method of lubrication for the various parts of the gear it would appear to be desirable to make the clutch of the "wet" type. This would obviate the need for taking precautions for excluding the nil from the clutch compartment—not an easy matter.
Our experience of gears of the kind which we have investigated previously is that the force necessary to control such a member as G and its pinion (r) is in the nature of slippage, and is wasted power, therefore the net result obtained has been a reduction of speed without any gain in torque, a common trouble with'svariable-speed devices.