This is Ackermann steering system for four wheelers with rotary steering torque transmission arm rather translating one. Unlike Ackermann mechanism which can turn the inner wheel by maximum of 45 degree this steering system can turn the wheels by 180 degree or even 360 degree along clockwise or anticlockwise direction.
It comprises 1) Upper steering subsystem (US) which active while steering towards left direction, 2) Lower steering subsystem which is active while steering towards right direction, 3) Auto-mechanical switching mechanism (SM) which (mutually exclusively) switches steering operation between (US) and (LS).
(US) and (LS) has three gear sets central, left and right. Central gear set is connected to left and right gear sets via steer torque transmission arms. When handle is rotated upper gear of central gear set of (US) and lower gear of central gear set of (LS) is rotated and the steering action is transmitted to left and gear sets via left and right gears of central gear sets and steering arms. This causes left and right steering shafts to rotate. (SM) does not require extra operation from lever etc and instead gets operated as a part of steering action to work as inter-gear switching clutch mechanisms.It consists of three coaxial tubular structures 1)inner tube is external spur gear coaxially attached to(left or right) steering shaft act as sleeve gear to guide mid tube along vertical direction 2)Mid tube is is internal spur gear acts as hub gear with crown gear (with dog teeth) on upper and lower side and has barrel cam follower attached to its outer surface 3)outer tube has has barrel groove of type dwell-rise-dwell engraved at its inner surface which guide the mid tube along vertical direction via barrel cam follower. Outer tube is fixedly attached to frame. When steering shaft is rotated, mid tube move up or down and crown gear engages with crown gear attached to upper and lower bevel gear.
Dog teeth crown gears are such that at no point steering shafts are disengaged with (US) and (LS) simultaneosly. Ellptic gear set helps to avoid locking condition in the vicinity of neutral steer position and being of variable gear ratio provide more precise Pro/Anti Ackermann steering. Orientation of Ascent portion of Groove in (SM) determines whether the steering system provides Pro or Anti Ackermann steering. Left orientation provide Pro-Ackermann and right orientation provide Anti-Ackermann steering. Parts can be concealed. Since this steering system can turn the wheels by 180 degree it can be usefull for wheeled excavators. Switching mechanism can be battery powered solenoid based actuator. Components can be integrated with the frame and does not occupy extra space. For example Davis steering requires longer hoods for formula one racing cars. This steering system does not require specialized components like recirculating ball screws etc and therefore requires less frequent maintenance. Spare parts inventory management is easier.