Patent ID: 11958547
Assignee: KNORR-BREMSE COMMERCIAL VEHICLE SYSTEMS JAPAN LTD.
Field: Transport (Mechanical engineering)
Classification: CPC B | IPC B

Claim 0:
1. A steering device comprising:
a steering mechanism having a steering shaft and a transmission mechanism, wherein
the steering shaft has a first shaft, a second shaft, a third shaft, a fourth shaft, a first torsion bar and a second torsion bar,
the first shaft and the second shaft are connected to each other through the first torsion bar,
the first shaft can be rotated according to driver's steering operation,
the third shaft is connected to the second shaft,
the third shaft and the fourth shaft are connected to each other through the second torsion bar,
the third shaft has a third shaft valve portion,
the fourth shaft has a fourth shaft valve portion, forms a rotary valve together with the third shaft, and can selectively supply working fluid, which is externally supplied, to a first fluid chamber and a second fluid chamber according to torsion of the second torsion bar, and
the transmission mechanism transmits rotation of the fourth shaft to steered wheels;

an electric motor having an electric motor output shaft and being able to rotate according to a motor command signal generated on the basis of a steering torque signal;
a reduction gear provided between the electric motor output shaft and the second shaft and transmitting a rotation force of the electric motor to the second shaft;
a first housing having a first housing body, a sensor accommodating space and a reduction gear accommodating space, wherein
the first housing body is formed as a single-piece member by molding,
the sensor accommodating space is provided at an inner side of the first housing body, and
the reduction gear accommodating space is provided at the inner side of the first housing body, and accommodates the reduction gear;

a second housing having a second housing body, a rotary valve accommodating space, a fourth shaft accommodating space and a fluid chamber, wherein
the second housing body is connected to the first housing,
the rotary valve accommodating space is provided at an inner side of the second housing body, and accommodates the rotary valve,
the fourth shaft accommodating space is provided at the inner side of the second housing body, and accommodates the fourth shaft, and
the fluid chamber is provided at the inner side of the second housing body;

a piston provided inside the second housing, dividing the fluid chamber into the first fluid chamber and the second fluid chamber and providing a steering force to the transmission mechanism according to a pressure difference of the working fluid between the first fluid chamber and the second fluid chamber;
a torque sensor provided in the sensor accommodating space, detecting a steering torque generated at the steering mechanism according to a torsion amount of the first torsion bar and outputting the steering torque signal; and
a control unit including a microprocessor, wherein
the microprocessor is configured to generate the motor command signal on the basis of the steering torque signal.