A work machine, such as a hauler at a mining site, includes a conductor rod housing concentric metal tubes for receiving electrical power from a contactor sliding on a power rail. A head-end interface of the conductor rod proximate the work machine includes metallic rings spaced apart and extending circumferentially around the head-end interface. Bores pass longitudinally through the head-end interface and into cavities within the conductor rod between the concentric metal tubes. The metallic rings enable the delivery of electrical power radially from the conductor rod for powering the work machine, while the bores enable the delivery of pneumatic power longitudinally into the conductor rod for powering axial movement of the conductor rod.

A motor driving device includes N units (N is a natural number equal to or greater than 2) of inverters configured to control N units of motors, respectively, a×N units (a is a natural number) of cables configured to allow connection between the N units of inverters and the N units of motors, respectively, and a PWM signal output unit configured to transmit a PWM signal to the N units of inverters. The N units of inverters and the a×N units of cables are divided into M groups (M≤N). The PWM signal output unit outputs the PWM signal for driving at least one inverter belonging to each group of the M groups so that the PWM signals have phase differences shifted by 360 degrees/M among the groups.

A motor driving device includes N units (N is a natural number equal to or greater than 2) of inverters configured to control N units of motors, respectively, aN units (a is a natural number) of cables configured to allow connection between the N units of inverters and the N units of motors, respectively, and a PWM signal output unit configured to transmit a PWM signal to the N units of inverters. The N units of inverters and the aN units of cables are divided into M groups (MN). The PWM signal output unit outputs the PWM signal for driving at least one inverter belonging to each group of the M groups so that the PWM signals have phase differences shifted by 360 degrees/M among the groups.

A work machine, such as a hauler at a mining site, includes a conductor rod housing concentric metal tubes for receiving electrical power from a contactor sliding on a power rail. A head-end interface of the conductor rod proximate the work machine includes metallic rings spaced apart and extending circumferentially around the head-end interface. Bores pass longitudinally through the head-end interface and into cavities within the conductor rod between the concentric metal tubes. The metallic rings enable the delivery of electrical power radially from the conductor rod for powering the work machine, while the bores enable the delivery of pneumatic power longitudinally into the conductor rod for powering axial movement of the conductor rod.

A power cable and method of forming the cable that includes a first conductor guide that includes (i) a first distal receiving hole and (ii) a first axial receiving hole on a longitudinal axis of the power cable. The power cable also includes a second conductor guide that includes (i) a second distal receiving hole and (ii) a second axial receiving hole on the longitudinal axis. The power cable also includes a flexible drive shaft that is disposed in the first axial receiving hole and the second axial receiving hole and a conductor that twists around the longitudinal axis. The conductor is disposed in the first distal receiving hole and the second distal receiving hole.

A work machine, such as a hauler at a mining site, includes a conductor rod housing concentric metal tubes for receiving electrical power from a contactor sliding on a power rail. A head-end interface of the conductor rod proximate the work machine includes metallic rings spaced apart and extending circumferentially around the head-end interface. Bores pass longitudinally through the head-end interface and into cavities within the conductor rod between the concentric metal tubes. The metallic rings enable the delivery of electrical power radially from the conductor rod for powering the work machine, while the bores enable the delivery of pneumatic power longitudinally into the conductor rod for powering axial movement of the conductor rod.

Disclosed herein is a power cable that includes a first conductor guide that includes (i) a first distal receiving hole and (ii) a first axial receiving hole on a longitudinal axis of the power cable. The power cable also includes a second conductor guide that includes (i) a second distal receiving hole and (ii) a second axial receiving hole on the longitudinal axis. The power cable also includes a flexible drive shaft that is disposed in the first axial receiving hole and the second axial receiving hole and a conductor that twists around the longitudinal axis. The conductor is disposed in the first distal receiving hole and the second distal receiving hole. Methods for forming the power cable are also disclosed herein.