A brake is operationally coupled by gear engagement to an axle of a device, whereby turning on the brake prevents the axle from rotating. Monitoring condition of the brake includes driving the axle of the device in a first rotation direction when the brake has been turned on. The axle of the device is driven in a second rotation direction when the brake has been turned on. A first position angle of the axle of the device, which follows from driving the axle of the device in the first rotation direction, is measured. A second position angle of the axle of the device, which follows from driving the axle of the device in the second rotation direction, is measured. A clearance of the gear engagement of the brake is determined on the basis of a difference of the first and the second position angles.

An electric crane contains: a body and an electrical box. The body includes a drive device, a roller, a lift assembly, and a hanging assembly. The electrical box is electrically connected with an operation lever configured to be manually controlled by a user, and the operation lever has multiple switches. The drive device is a permanent magnet servo motor and has an encoder. The electrical box includes a control unit electrically connected with the encoder to feed back a detected position of a rotator of the permanent magnet servo motor and to compare whether an operating instruction of the permanent magnet servo motor matches with a rotating speed of the permanent magnet servo motor. The operation lever has a rotary hand wheel. The operation lever has a pulse signal generator. The pulse signal generator is electrically connected with the electrical box.

An electric crane contains: a body and an electrical box. The body includes a drive device, a roller, a lift assembly, and a hanging assembly. The electrical box is electrically connected with an operation lever configured to be manually controlled by a user, and the operation lever has multiple switches. The drive device is a permanent magnet servo motor and has an encoder. The electrical box includes a control unit electrically connected with the encoder to feed back a detected position of a rotator of the permanent magnet servo motor and to compare whether an operating instruction of the permanent magnet servo motor matches with a rotating speed of the permanent magnet servo motor. The operation lever has a rotary hand wheel. The operation lever has a pulse signal generator. The pulse signal generator is electrically connected with the electrical box.

A method for operating a conveying system is provided. An overhead hoist transport (OHT) vehicle is provided, wherein the OHT vehicle includes a gripping member configured to grip and hold a carrier, and a receiver configured to receive a signal. The signal is transmitted to the receiver of the OHT vehicle. The OHT vehicle is moved toward the carrier, and the carrier is gripped by the gripping member of the OHT vehicle. A lifting force is determined based on a weight of a carrier, a number of workpieces in the carrier, or a vertical distance between the OHT vehicle and the carrier, and the lifting force is applied to the carrier.

A method for operating a conveying system is provided. An overhead hoist transport (OHT) vehicle is provided, wherein the OHT vehicle includes a gripping member configured to grip and hold a carrier, and a receiver configured to receive a signal. The signal is transmitted to the receiver of the OHT vehicle. The OHT vehicle is moved toward the carrier, and the carrier is gripped by the gripping member of the OHT vehicle. A lifting force is determined based on a weight of a carrier, a number of workpieces in the carrier, or a vertical distance between the OHT vehicle and the carrier, and the lifting force is applied to the carrier.

A method for controlling operation of a winch, which has a capstan drive unit for hauling a cable into the winch and for paying the cable out of the winch, a main drive for driving the capstan drive unit, a cable drum for receiving the cable by winding up and unwinding the cable, a drum drive for driving the cable drum, wherein the drum drive and the main drive are operable independently of one another, and a rotational speed measuring device which is arranged in a cable inlet portion of the winch. The method has a step of reading a first rotational speed from the main drive and a second rotational speed from the rotational speed measuring device. In addition, the method has a step of determining a torque value for setting a torque of the drum drive depending on the first rotational speed and the second rotational speed.

A transport vehicle for transporting a transportation-target object to a placement location that is provided at a lower position, includes: a supporting portion configured to support the transportation-target object; a lifting/lowering portion configured to lift and lower the transportation-target object in a suspended state; and a weight detecting portion configured to detect a weight of the transportation-target object, wherein a lowering speed of the transportation-target object is increased after a detection value that is detected by the weight detecting portion while the transportation-target object is being lowered by the lifting/lowering portion in a state where the transportation-target object is supported by the supporting portion has become smaller than or equal to a first set value, and thereafter, the supporting of the transportation-target object by the supporting portion is canceled after the suspending of the transportation-target object by the lifting/lowering portion has been canceled.

A flat storage facility includes a storage/retrieval device having a Y-direction moving member with a length corresponding to the width of a storage item placement plane in an X direction and that is movable in a forward/backward Y direction of the storage item placement plane. A carriage is supported on the Y-direction moving member and is movable in the X direction. A storage item gripping mechanism is supported on the carriage so as to be freely raised and lowered. Lowering of the storage item gripping mechanism is controlled such that downward flexural deformation distances between end portions of the Y-direction moving member in the X direction are determined. Lowering distance adjustment values of the storage item gripping mechanism for the storage item placement points are set based on the downward flexural deformation distances, and lowering distances of the storage item gripping mechanism are reduced by the lowering distance adjustment values.

A flat storage facility includes a storage/retrieval device having a Y-direction moving member with a length corresponding to the width of a storage item placement plane in an X direction and that is movable in a forward/backward Y direction of the storage item placement plane. A carriage is supported on the Y-direction moving member and is movable in the X direction. A storage item gripping mechanism is supported on the carriage so as to be freely raised and lowered. Lowering of the storage item gripping mechanism is controlled such that downward flexural deformation distances between end portions of the Y-direction moving member in the X direction are determined. Lowering distance adjustment values of the storage item gripping mechanism for the storage item placement points are set based on the downward flexural deformation distances, and lowering distances of the storage item gripping mechanism are reduced by the lowering distance adjustment values.

A flat storage facility includes a storage/retrieval device having a Y-direction moving member that is horizontally movable at a certain height above a storage item placement plane. A carriage is horizontally movable in an X direction on the Y-direction moving member, and a storage item gripping mechanism is provided in the carriage. The storage/retrieval device performs storage/retrieval on a storage item between the storage/retrieval device and respective storage item placement points set on the storage item placement plane. The storage item placement plane is divided into a plurality of unit sections at various heights with respect to a reference plane. When the storage/retrieval operation is performed with the storage/retrieval device, the lowering distance of the storage item gripping mechanism with respect to the carriage is adjusted according to the height of the unit section to which the storage item placement point of a storage/retrieval target belongs.