This motor shaft state detection method has: a rotation determination step for determining, using a detected current waveform of a motor, whether or not to be a non-rotational state in which the rotational speed of the motor is smaller than a predetermined speed; a current determination step for determining whether or not to be a supply state in which the absolute value of current supplied to the motor is larger than a predetermined reference value; and a determination step for, when it is determined to be the non-rotational state in the rotation determination step and it is determined to be the supply state in the current determination step, determining that the motor is in a shaft locked state.

ThE load weight derivation device comprises a calculation unit that calculates a contraction amount of a spring in a suspension positioned between a vehicle body and a vehicle wheel, and a derivation unit that derives the weight loaded on the vehicle body using the contraction amount calculated by the calculation unit.

A suspension device includes a spring, a jack, a reservoir chamber which reserves the oil, a first pump, a second pump an opening and closing unit. The second pump is configured to cause the oil to flow into the housing chamber and to cause the oil to flow out from the housing chamber.

A shock assembly is disclosed. The assembly includes a damper chamber having an outer wall with a first inner diameter (ID). A secondary chamber within the damper chamber, the secondary chamber comprising an exterior wall with an external diameter (ED) less than the ID of the outer wall to form an annular region therebetween. A damping piston coupled to a piston rod, the damping piston disposed in the secondary chamber and axially movable relative to the secondary chamber, the damping piston to bifurcate the secondary chamber into a compression side and a rebound side. A valve to control a flow of a working fluid between the annular region and the secondary chamber.

A level control system adjusts the level of a rail vehicle, and includes at least one level control cylinder and a level control piston. The level control piston is at least partly received in the level control cylinder in a movable manner. The level control system has at least one first hydraulic connection, wherein the level control cylinder or the level control piston has a collared shoulder, in which at least one first fluid channel connected to the first hydraulic connection is arranged. At least one first attachment for receiving the first hydraulic connection is provided along the collared shoulder, the first attachment, being arranged on the collared shoulder tangentially to the longitudinal axis of the level control cylinder or of the level control piston such that at least one tangential external fluid connection on the collared shoulder can be connected to the at least one first hydraulic connection.

A height-adjustable spring arrangement for a vehicle includes a bearing spring, a first limiting cylinder with a first limiting cylinder pot and a first limiting piston, a second limiting cylinder with a second limiting cylinder pot and a second limiting piston, and a guide cylinder with a guide cylinder pot, a displaceable guide piston in the guide cylinder pot and a guide piston rod fixed on the guide piston and extending out of the guide cylinder pot along a longitudinal axis of a bearing spring and through the bearing spring. The guide piston rod is displaceable by the first and second limiting cylinders such that a spring preload acting on the bearing spring and a negative spring path of the bearing spring remain constant as a result of a height adjustment.

Integrated multiple actuator electro-hydraulic systems as well as their methods of use are described. Depending on the particular application, the integrated electro-hydraulic systems may exhibit different frequency responses and/or may be integrated into a single combined unit.

A motor control method includes a determination step of determining whether a contact portion exists, which is a portion where the screw and the nut member are in contact with each other at a location different from a mating portion, when the motor is energized to move the nut member in a first direction, and when the contact portion is determined to exist in the determination step, a return step of energizing the motor to move the nut member in a second direction opposite to the first direction until the contact portion no longer exists.

Integrated multiple actuator electro-hydraulic systems as well as their methods of use are described. Depending on the particular application, the integrated electro-hydraulic systems may exhibit different frequency responses and/or may be integrated into a single combined unit.

The fluid supply device comprises a screw, which has a male thread formed thereon and rotates, and a nut, which has a female thread formed therein that meshes with the male threading and which, by the screw rotating in a first direction, i.e., the circumferential direction, moves towards a first end in the rotation axis direction, and which, by moving with said movement a piston that forms a reservoir chamber, discharges a fluid stored in the reservoir chamber, wherein, if the fluid is discharged and if the screw is not rotating, first surfaces which form the threading of the male screw and second surfaces which form the threading of the female screw are in contact with each other, and second surfaces which form the threading of the male screw and first surfaces which form the threading of the female screw are not in contact with each other.