371 Epicyclic overdrive gearing
Epicyclic gear train overdrives are so arranged that the input shaft drives the pinion carrier while the output shaft is driven by the annular gear ring Figs 3.27 and 3.28 . The gear train may be either of simple single stage or compound double stage design and the derived formula for each arrangement is as follows where A number of annulus ring gear teeth where A number of annulus ring gear teeth Ps number of small planet gear teeth Pl number of large planet gear teeth The amount of overdrive...
1013 Tandem and triaxle bogies
A heavy goods vehicle is normally laden so that about two thirds or more of the total load is carried by the rear axle. Therefore the concentration of weight over a narrow portion of the chassis and on one axle, even between twin wheels, can be excessive. In addition to the mechanical stresses imposed on the vehicle's suspension system, the subsoil stress distribution on the road for a single axle Fig. 10.85 a is considerably greater than that for a tandem axle bogie Fig. 10.85 b for similar...
716 Checking crownwheel and pinion tooth contact
Prepare crownwheel for examining tooth contact marks Fig. 7.8 After setting the correct backlash, the crownwheel and pinion tooth alignment should be checked for optimum contact. This may be achieved by applying a marking cream such as Prussian blue, red lead, chrome yellow, red or yellow ochre etc. to three evenly spaced groups of about six teeth round the crownwheel on both drive coast sides of the teeth profiles. Apply a load to the meshing gears by holding the crownwheel and allowing it to...
625 Birfield joint based on the Rzeppa Principle
Alfred Hans Rzeppa pronounced sheppa , a Ford engineer in 1926, invented one of the first practical Fig. 6.33 Early Rzeppa constant velocity joint Fig. 6.33 Early Rzeppa constant velocity joint constant velocity joints which was able to transmit torque over a wide range of angles without there being any variation in the rotary motion of the output shafts. An improved version was patented by Rzeppa in 1935. This joint used six balls as intermediate members which where kept at all times in a...
14 Trailer and caravan drawbar couplings
1.4.1 Eye and bolt drawbar coupling for heavy goods trailers Figs l.25 and l.26 Drawbar trailers are normally hitched to the truck by means of an 'A' frame drawbar which is coupled by means of a towing eye formed on the end of the drawbar Fig. l.25 . When coupled, the towing eye hole is aligned with the vertical holes in the upper and lower jaws of the truck coupling and an eye bolt passes through both coupling jaws and drawbar eye to complete the attachment Fig. l.26 . Lateral drawbar swing is...
11 Integral body construction
The integral or unitary body structure of a car can be considered to be made in the form of three box compartments the middle and largest compartment stretching between the front and rear road wheel axles provides the passenger space, the extended front box built over and ahead of the front road wheels enclosing the engine and transmission units and the rear box behind the back axle providing boot space for luggage. These box compartments are constructed in the form of a framework of ties...
Operation of the automatic drawbar coupling
Fig. 1.26 In the uncoupled position the eyebolt is held in the open position ready for coupling Fig. 1.26 a . When the truck is reversed, the jaws of the coupling slip over the towing eye and in the process strike the conical lower end of the eye bolt Fig. 1.26 b . Subsequently, the eye bolt will lift. This trips the spring-loaded wedge lever which now rotates clockwise so that it bears down on the eye bolt. Further inward movement of the eye bolt between the coupling jaws aligns the towing...