Brake system for electrically powered vehicles

A method of providing a brake system for braking a drive train having an existing output shaft rotated by a drive gear train driven by an electric motor capable of generating a maximum drive torque at the output shaft, said output shaft being connected to a plurality of axles each for driving a corresponding wheel of a vehicle having a fluid system for providing a fluid under pressure to operate fluid powered components of the vehicle, said method comprising:

• assembling a brake device comprising a rotatably mounted brake shaft and brake elements capable of applying a maximum braking torque to said brake shaft;
• substituting a modified output shaft for said existing output shaft;
• and,
• assembling a reduction gear train comprising a brake gear fixed to said brake shaft for rotation therewith, and output gear fixed to said modified output shaft for rotation therwith, said reduction gear train being arranged to transmit torque between said modified output shaft and said brake shaft, and said reduction gear train being selected to provide a reduction gear ratio sufficient to reduction said maximum drive torque to a drive torque at said brake shaft substantially less than said maximum braking torque;
• wherein said brake elements comprise at least one stationary disc held against rotation relative to a housing, at least one rotating disc mounted on said brake shaft for rotation therewith, and at least one compression element for pressing together said stationary disc and said rotating disc to provide a braking torque;
• wherein said method further comprises enclosing said stationary and rotating discs in a housing having a cooling inlet and a cooling outlet and assembling a fluid system;
• wherein said fluid system comprises a pump for pressurizing said fluid and a container for containing a supply of said fluid, said pump and said container being remote from said housing,
• and wherein said fluid system further comprises a conduit for supplying a cooling flow of said fluid said pump to said cooling inlet, a conduit for returning a flow of said cooling fluid from said cooling outlet to said container.