Control for an electromagnetic brake for a multiple-ratio power transmission that has a brake actuation counter

An electromagnetic brake for a vehicle powertrain for a wheeled vehicle, the powertrain comprising an engine, a multiple-ratio power transmission having a housing enclosing multiple-ratio gear elements, a power output shaft driveably connected to vehicle traction wheels, a power input shaft driveably connected to the multiple-ratio gear elements and a master clutch selectively connecting the power input shaft to the engine, the master clutch being enclosed by a master clutch housing forming a part of the transmission housing, the electromagnetic brake comprising:

• a stator coil housing secured to the transmission housing, the stator coil housing enclosing a stator coil surrounding the power input shaft and defining with the coil housing an electromagnetic pole face;
• a stator coil circuit including a voltage source and a switch for opening and closing the stator coil circuit;
• an armature plate having a hub portion secured to the power input shaft and a peripheral portion disposed adjacent the stator coil;
• a control system for electrically energizing the stator coil thereby effecting frictional engagement of the armature plate with the pole face as an electromagnetic flux flow path is established around the stator coil through the stator coil housing and the peripheral armature plate portion;
• the control system further including a protective circuit that is adapted to receive at least one data input from a databus, the protective circuit determining whether the data input is within a predetermined range that is appropriate for energizing the stator coil wherein the protective circuit further comprises a software timer that times the period during which the stator coil for the electromagnetic brake is energized.

An electromagnetic brake for a vehicle powertrain for a wheeled vehicle, the powertrain comprising an engine, a multiple-ratio power transmission having a housing enclosing multiple-ratio gear elements, a power output shaft driveably connected to vehicle traction wheels, a power input shaft driveably connected to the multiple-ratio gear elements and a master clutch selectively connecting the power input shaft to the engine, the master clutch being enclosed by a master clutch housing forming a part of the transmission housing, the electromagnetic brake comprising:

• a stator coil housing secured to the transmission housing, the stator coil housing enclosing a stator coil surrounding the power input shaft and defining with the coil housing an electromagnetic pole face;
• a stator coil circuit including a voltage source and a switch for opening and closing the stator coil circuit;
• an armature plate having a hub portion secured to the power input shaft and a peripheral portion disposed adjacent the stator coil;
• a control system for electrically energizing the stator coil thereby effecting frictional engagement of the armature plate with the pole face as an electromagnetic flux flow path is established around the stator coil through the stator coil housing and the peripheral armature plate portion;
• the control system further including a protective circuit that is adapted to receive at least one data input from a databus, the protective circuit determining whether the data input is within a predetermined range that is appropriate for energizing the stator coil, wherein the protective circuit permits operation of the electromagnetic brake when no data input is received from databus, and wherein the protective circuit includes a software timer that times the duration of brake application.