Auxiliary axle and suspension assembly

A vehicle suspension assembly, comprising:

• an axle assembly having a first end and a second end;
• a first mounting bracket and a second mounting bracket each adapted to couple to a vehicle frame assembly;
• a first trailing arm having a first end pivotably coupled to the first mounting bracket, and a second end pivotably coupled to the first end of the axle assembly;
• a second trailing arm having a first end pivotably coupled to the second mounting bracket, and a second end pivotably coupled to the second end of the axle assembly;
• a first air spring assembly coupled to a first end of the axle assembly such that a longitudinal axis of the first air spring assembly inclines inwardly from the first end of the axle assembly;
• a second air spring assembly coupled to the second end of the axle assembly such that a longitudinal axis of the second air spring assembly inclines inwardly from the second end of the axle assembly;
• wherein a natural frequency of the suspension assembly is less than or equal to about 3 Hz.

A vehicle suspension assembly, comprising:

• an axle member having a first end and a second end, the axle member movable between a first position, wherein at least one tire coupled with the axle member contacts a ground surface, and a second position, wherein the at least one tire is spaced from the ground surface;
• a first mounting bracket coupled to a vehicle frame assembly;
• a first trailing arm having a first end pivotably coupled to the first mounting bracket, and a second end pivotably coupled to the first end of the axle member;
• a second mounting bracket adapted to couple to a vehicle frame assembly;
• a second trailing arm having a first end pivotably coupled to the second mounting bracket, and a second end pivotably coupled to the second end of the axle member;
• a first lift arrangement, comprising:
• a first diaphragm chamber having a first push plate and a flexible bladder, the first push plate of the first diaphragm chamber dividing the first diaphragm chamber into a first compartment and a second compartment, the first compartment of the first diaphragm chamber being adjustably pressurized to move the first push plate of the first diaphragm chamber;
• a second diaphragm chamber having a second push plate including a flexible bladder, the second push plate of the second diaphragm chamber dividing the second diaphragm chamber into a first compartment and a second compartment, the first compartment of the second diaphragm chamber being adjustably pressurized to move the second push plate of the second diaphragm chamber;
• and
• at least one push rod defining a single longitudinal axis and connected to the first push plate and the second push plate such that pressurization of the first and second diaphragm chambers cause a translational movement of the at least one push rod, wherein the at least one push rod is operably coupled with the vehicle suspension assembly such that translational movement of the at least one push rod causes the axle member to move between the first and second positions, and wherein the first diaphragm chamber and the second diaphragm chamber are both fixed with respect to a select one of the first trailing arm and the vehicle frame assembly.