1 THE TITLE Eclipse Roller-Drive Direction Sensing Power-Divider TECHNICAL FIELD This invention relates to improvements in devices used as power dividers in bogie drive mechanisms in automotive drive trains.
In the past art it has been very difficult to obtain a bogie-drive, which exhibits all necessary characteristic, of speed differential between the bogie axle sets without excessive WHEEL-SLIP, or WIND-UP under all operating conditions encountered, in the various environments in which these vehicles go 10 need to operate. In particular with regard to WIND-UP and the damage caused by it in the driveline components, due to build up of excessive stress loads. The present invention allows speed differential between the axle sets, 0 via the overrun clutch mechanism which is direction sensing thereby accommodating the requirements of the driveline in a bogie-drive of greater speed of rotation of the rear axle set, compared to the intermediate S set, in the direction of travel .This requirement remaining at all times that the wheels of the vehicle move in anything except a perfectly straight line on a perfectly flat smooth surface, this speed differential requirement derives from the fact that the rearmost axle set has a greater turning radius than the intermediate axle set and therefore the wheels on the rear axle set will always need to be able to rotate at a greater speed in the direction of travel than the intermediate axle set. The present invention allows drive to be passed through to the rear axle set from the intermediate axle set via the overrun clutch 2/8 mechanism as soon as the need arises by this means the rear axle set is always driven off the intermediate axle set when the extra drive is needed but the rear axle set is allowed to rotate faster in the direction of travel when the need arises to eliminate wind-up, this roller drive direction sensing clutch eliminates WIND-UP in the drive train whilst exhibiting the favourable full drive characteristics as in a locked drive, without need for any operator 30 intervention, these improvements all derive from the drive medium used and the direction sensing function of the present invention .When in operation the present invention will only accept drive torque from the intermediate axle set when the intermediate axle set is being driven faster in the direction of rotation than the rear axle set is rotating due to its tyres being ground driven, 35 as in the case of a slight loss of traction at the interface of the intermediate axle set tyres and the ground surface, whilst the rear axle set retains full traction, in this situation the rear axle set will accept as much drive torque as its tyres are able to transfer without loss of traction It will be seen that this power divider will allow the first axle set to take priority over the second axle set while the first axle set has full traction at its' wheels, however allowing the axle set with the greater traction to take the greater percentage of drive torque available at any instant in time should a loss of full traction occur at the first drive axle wheels. The axles will equally share the drive torque in the situation of reduced traction as they will both be driven at exactly the same speed and this equal drive speed will translate into the best possible 3/8 torque transfer as each wheel will transfer its exact share of the available drive torque, without the usual wheel slip and resulting loss of locomotion.
DESCRIPTION
This invention Figs 1 and 2, is.an automatic power divider consisting of a drive input shaft which has a section, made up of drive faces which are flat and the drive faces are on the external circumference of the said drive input shaft and this configuration is continued for sufficient length of the shaft to allow a set of rollers(3), fitted loosely in a rigid cage to be supported by the flat drive faces these rollers engage with the inside of the driven member which has a round cylindrical surface the same length as the drive rollers and an integral drive output shaft the faces and driven member surface both being a suitable length to engage the drive rollers for their entire length ,the number of drive faces(2) and drive rollers will be the same, thereby utilising the same drive rollers to drive both forward and reverse or in the alternate 60 in Figs 3 and 4 the drive rollers are twice the number of the drive faces to allow the forward and reverse drive to be transmitted by a separate set of drive rollers for each direction the driven member contains a Belleville spring (8)Fig 1 or in the alternate design Figs 3 and 4 wire springs which act as a brake for the drive roller cage to allow the drive roller cage to sense the direction of rotation, by causing the drive roller cage to always be retarded against the direction of rotation of the drive the resulting retardation allows the drive rollers to engage with the drive faces and driven member 4/8 to transmit the drive. If the driven member is caused to rotate faster than the drive input shaft the drive rollers disengage from the drive faces (2) and allow the driven member to rotate faster than the drive input shaft in the direction of drive allowing driveline windup to be avoided instantly, as the requirement for bogie type drivelines is to allow the driven member to be able to rotate faster in the direction of drive to eliminate windup because the rearmost axle set is further away from the front wheels and must by necessity 75 travel a longer path in turns, this new power divider always prevents windup In the alternate design Figs 3 and 4, applying the roller drive power divider to assist a viscous coupling to cope with extreme torque transfer peaks, the aforementioned Belleville spring is replaced by two wire springs which are adjusted so as to center the roller cage(4) on the respective driving flats (2)of the input shaft and the roller drive does not transfer any torque until the viscous coupling(l 0)begins to overload, at which point the wire springs holding the roller cage cause the drive rollers to engage with both the drive flats(2) and the outer driven member(5) thereby transferring drive torque, while ever the load is sufficient to over speed the viscous coupling or until the driven member(5) rotational speed is the same or less than the input shaft(l) speed, whence the drive rollers disengage and take a neutral position again.
1/ This automatic roller drive power divider can sense direction of rotation of the driveline and so always directs drive torque to the axle set which has the