Provided is a crane which can suppress deformation and vibration of a crane structure in travel and stop of the crane. Inverters are installed respectively in travel devices which are arranged on the opposite sides with a gap in a transverse direction. Each of the inverters independently measures a torque generated in a motors to which the inverter is connected and reduces the rotation speed in the command from a controller to the motor such that the greater the measured torque is, the greater a ratio of reduction is.

A sprocket for a crawler undercarriage comprises a plurality of sprocket teeth for engagement with a crawler track, wherein the sprocket teeth are arranged in a plurality of similar circumferential segments along the sprocket, and wherein an odd number of circumferential segments is provided.

A sprocket for a crawler undercarriage comprises a plurality of sprocket teeth for engagement with a crawler track, wherein the sprocket teeth are arranged in a plurality of similar circumferential segments along the sprocket, and wherein an odd number of circumferential segments is provided.

A driven reel trolley includes a carriage having a lower carriage section formed from opposing longitudinal members and transverse connecting members extending between and connecting the opposing longitudinal members. A pair of opposing support beams extend upwardly from the lower carriage. Each beam has a shaft support opening at about the top thereof for accommodating an associated shaft. A pair of non-driven wheels is mounted to the lower carriage section on opposing transverse sides of the lower carriage section and a pair of drive wheels is mounted to the lower carriage section, on opposing transverse sides of the lower carriage section, spaced from the non-driven wheels. A pair of drive trains operably connects the shaft and a respective one of the drive wheels. Each drive train includes a transmission and each transmission is operably engageable with and disengageable from the shaft and its respective drive wheel.

A travel control section 60b is configured to control the revolution velocities of transversely opposite travel motors 51 and 52 such that when turning amount command signals are inputted from a turning amount operation dial 48, transversely opposite crawler travel devices 12a and 12b are caused to realize a turn according to the turning amount command signals by decelerating the traveling velocities of the transversely opposite crawler travel devices 12a and 12b from a target straight traveling velocity set by a travel operation lever 47 by equal values of velocity which are predetermined according to the turning amount command signals inputted from the turning amount operation dial 48 and further decelerating the traveling velocity of the crawler travel device 12a or 12b which is positioned inwardly relative to the other in the turning direction.

A travel control section 60b is configured to control the revolution velocities of transversely opposite travel motors 51 and 52 such that when turning amount command signals are inputted from a turning amount operation dial 48, transversely opposite crawler travel devices 12a and 12b are caused to realize a turn according to the turning amount command signals by decelerating the traveling velocities of the transversely opposite crawler travel devices 12a and 12b from a target straight traveling velocity set by a travel operation lever 47 by equal values of velocity which are predetermined according to the turning amount command signals inputted from the turning amount operation dial 48 and further decelerating the traveling velocity of the crawler travel device 12a or 12b which is positioned inwardly relative to the other in the turning direction.

A braking system for a rail-mounted traveling unit of a transfer vehicle. A brake arrangement can be adjusted between a braking position and a venting position and which is designed to exert a settable braking torque in the braking position. A control unit is designed to determine a braking torque and to activate accordingly the brake arrangement. A sensor arrangement detects an operating state of the transfer vehicle and external operating influences and transmits these to the control unit. During operation of the transfer vehicle the sensor arrangement detects the operating state of the transfer vehicle and the external operating influences on the transfer vehicle at periodic intervals and transmits these to the control unit as operating state data and operating influence data. During a braking process, the control unit determines a braking torque to be applied and activates the brake arrangement.

Provided is a crane which can suppress deformation and vibration of a crane structure in travel and stop of the crane. Inverters are installed respectively in travel devices which are arranged on the opposite sides with a gap in a transverse direction. Each of the inverters independently measures a torque generated in a motors to which the inverter is connected and reduces the rotation speed in the command from a controller to the motor such that the greater the measured torque is, the greater a ratio of reduction is.

Provided is a crane which can suppress deformation and vibration of a crane structure in travel and stop of the crane. Inverters are installed respectively in travel devices which are arranged on the opposite sides with a gap in a transverse direction. Each of the inverters independently measures a torque generated in a motors to which the inverter is connected and reduces the rotation speed in the command from a controller to the motor such that the greater the measured torque is, the greater a ratio of reduction is.

A sprocket for a crawler undercarriage comprises a plurality of sprocket teeth for engagement with a crawler track, wherein the sprocket teeth are arranged in a plurality of similar circumferential segments along the sprocket, and wherein an odd number of circumferential segments is provided.