Drive system for work machine, control device for work machine, control method for work machine, storage medium storing control program for work machine, and work machine

A control device for a work machine, the control device being applied to a work machine including:

• an upper body rotatable about a rotation axis relative to a lower body;
• a slew actuator configured to rotate the upper body relative to the lower body;
• a swing bracket coupled to the upper body and rotatable about a swing axis parallel to the rotation axis relative to the upper body;
• a swing actuator configured to rotate the swing bracket relative to the upper body;
• an electric actuator mounted to the swing bracket, the electric actuator being configured to output a torque about an axis intersecting the swing axis;
• and
• an attachment mounted to the electric actuator and driven by the electric actuator,
• the control device being configured to:
• perform specific control in which the swing actuator is controlled so as to maintain a constant rotational position of the swing bracket relative to the upper body;
• and
• when a load torque, which is a torque about the swing axis acting on the swing bracket during the specific control, has reached or exceeded a critical torque, perform load reduction control in which at least one of the slew actuator or the swing actuator is controlled so as to reduce the load torque.

A work machine comprising:

• an upper body rotatable about a rotation axis relative to a lower body;
• a slew actuator configured to rotate the upper body relative to the lower body;
• a swing bracket coupled to the upper body and rotatable about a swing axis parallel to the rotation axis relative to the upper body;
• a swing actuator configured to rotate the swing bracket relative to the upper body;
• an electric actuator mounted to the swing bracket, the electric actuator being configured to output a torque about an axis intersecting the swing axis;
• an attachment mounted to the electric actuator and driven by the electric actuator;
• and
• a control device configured to perform specific control in which the swing actuator is controlled so as to maintain a constant rotational position of the swing bracket relative to the upper body,
• wherein when a load torque, which is a torque about the swing axis acting on the swing bracket during the specific control, has reached or exceeded a critical torque, the control device performs load reduction control in which at least one of the slew actuator or the swing actuator is controlled so as to reduce the load torque.