Dual-axle vehicle corner assembly

Abstract

A dual-axle vehicle corner assembly which may include a sub-frame, a first arm connected to the sub-frame and rotatable with respect to the sub-frame about a first arm axis, the first arm having a first axle axis about which a first wheel rotates when connected to the first arm, a second arm connected to the sub-frame and rotatable with respect to the sub-frame about a second arm axis, the second arm having a second axle axis about which a second wheel rotates when connected to the second arm, and a suspension system comprising a piston assembly interconnecting the first arm and the second arm, the piston assembly is to controllably increase and decrease a length of the piston assembly to control a distance between the first axle axis and the second axle axis.

1 . A dual-axle vehicle corner assembly comprising:
 a sub-frame;   a first arm connected to the sub-frame and rotatable with respect to the sub-frame about a first arm axis, the first arm having a first axle axis about which a first wheel rotates when connected to the first arm;   a second arm connected to the sub-frame and rotatable with respect to the sub-frame about a second arm axis, the second arm having a second axle axis about which a second wheel rotates when connected to the second arm; and   a suspension system comprising a piston assembly interconnecting the first arm and the second arm, the piston assembly is to controllably increase and decrease a length of the piston assembly to control a distance between the first axle axis and the second axle axis;   wherein the first arm axis, the first axle axis, the second arm axis and the second axle axis are substantially parallel to each other.   
     
     
         2 . The assembly of  claim 1 , wherein the piston assembly is to controllably increase and decrease the length of the piston assembly to control a height of the sub-frame relative to a ground surface when the assembly is assembled to a vehicle platform. 
     
     
         3 . The assembly of  claim 1 , wherein the first arm axis coincides with the second arm axis. 
     
     
         4 . The assembly of  claim 1 , wherein the piston assembly, the first arm and the second arm are positioned at the same side of the sub-frame. 
     
     
         5 . The assembly of  claim 1 , wherein (i) the piston assembly and (ii) the first arm and the second arm are positioned at opposing sides of the sub-frame with respect to each other. 
     
     
         6 . The assembly of  claim 1 , wherein the piston assembly comprising:
 a housing;   a first piston coupled to the first arm and having a first piston head, and a second piston coupled to the second arm and having a second piston head, the first piston head and the second piston head being positioned within the housing and forming within the housing a first fluid chamber, a second fluid chamber and a third fluid chamber; and   a spring positioned within the housing between the first piston head and the second piston head.   
     
     
         7 . The assembly of  claim 6 , wherein the suspension system comprising:
 a fluid pump to alternately introduce fluid to and expel fluid from at least one of the first fluid chamber, the second fluid chamber or the third fluid chamber; and   a controller to operate the fluid pump to control at least one of a spring rate of the spring and the distance between the first axle axis and the second axle axis.   
     
     
         8 . The assembly of  claim 1 , wherein the piston assembly comprising:
 a housing connected to the first arm;   a first spring-loaded member and a second spring-loaded member positioned within the housing, the first spring-loaded member and the second spring-loaded member being parallel to each other and being connected to the second arm;   wherein springs of the first spring-loaded member and the second spring-loaded member are preloaded to set the distance between the first axle axis and the second axis axle.   
     
     
         9 . The assembly of  claim 8 , wherein the suspension system comprising:
 a liquid pump to alternately introduce liquid to and expel liquid from the housing; and   a controller to operate the liquid pump to control the length of the piston assembly and the distance between the first axle axis and the second axis axle.   
     
     
         10 . The assembly of  claim 1 , wherein the piston assembly comprising:
 a housing comprising:
 a first chamber, and 
 a second chamber; 
   a first piston positioned within the first chamber and connected to the first arm; and   a second piston positioned within the second chamber and connected to the second arm.   
     
     
         11 . The assembly of  claim 10 , wherein the suspension system comprising an accumulator in fluid communication with the first chamber of the housing, the accumulator comprising a pressurized gas. 
     
     
         12 . The assembly of  claim 10 , wherein the suspension system comprising two or more accumulators in fluid communication with the first chamber of the housing, each of the accumulators comprising a gas pressurized to a different pressure value than a gas in other accumulators. 
     
     
         13 . The assembly of  claim 10 , wherein the suspension system comprising:
 a liquid pump to alternately introduce liquid to and expel liquid from the second chamber of the housing; and   a controller to operate the liquid pump to control the length of the piston assembly and the distance between the first axle axis and the second axis axle.   
     
     
         14 . The assembly of  claim 10 , wherein the suspension system comprising a first damper interconnecting the housing and the first arm and a second damper interconnecting the housing and the second arm. 
     
     
         15 . The assembly of  claim 1 , wherein the piston assembly comprising:
 a housing comprising a housing cavity, the housing being connected to the first arm;   a first piston positioned within the housing cavity, the first piston comprising a first piston cavity; and   a second piston positioned within the first piston cavity and comprising a hollow channel in fluid communication with the first piston cavity, the second piston being connected to the second arm.   
     
     
         16 . The assembly of  claim 15 , wherein the suspension system comprising two or more accumulators in fluid communication with the housing cavity, each of the accumulators comprising a gas pressurized to a different pressure value than a gas in other accumulators. 
     
     
         17 . The assembly of  claim 15 , wherein the suspension system comprising:
 a liquid pump to alternately introduce liquid to and expel liquid from the first piston cavity; and   a controller to operate the liquid pump to control the length of the piston assembly and the distance between the first axle axis and the second axis axle.   
     
     
         18 . The assembly of  claim 15 , wherein the suspension system comprising a first damper interconnecting the sub-frame and the first arm and a second damper interconnecting the sub-frame and the second arm. 
     
     
         19 . The assembly of  claim 1 , comprising:
 a first connector connected to the first arm and rotatable about the first axle axis, the first connector to connect to the first wheel; and   a second connector connected to the second arm and rotatable about the second axle axis, the second connector to connect to the second wheel;   wherein at least one of: (i) the first connector is steerable relative to the first arm about a first steering axis or (ii) the second connector is steerable relative to the second arm about a second steering axis.   
     
     
         20 . The assembly of  claim 1 , wherein the first arm and the second arm are steerable about a steering axis relative to the sub-frame, the steering axis being positioned between the first axle axis and the second axle axis.