A transmission structure of a drilling machine contains: a housing, a drive shaft, a drive gear, a guide gear, a speed change gear assembly, a driven gear assembly, and a control knob. The housing include a first accommodation groove for housing the drive shaft, a second accommodation groove for accommodating the guide shaft, a third accommodation groove for housing the speed shaft, and a fourth accommodation groove for accommodating the driven shaft. The drive gear is connected on the drive shaft, and the guide gear is coupled on the guide shaft and meshes with the drive gear. The speed change gear assembly includes a connection gear and at least two speed change gears. The driven gear assembly includes at least two driven gears corresponding to at least two speed change gears respectively. The control knob configured to drive the driven gear assembly to move upward and downward.

A transmission structure of a drilling machine contains: a housing, a drive shaft, a drive gear, a guide gear, a speed change gear assembly, a driven gear assembly, and a control knob. The housing include a first accommodation groove for housing the drive shaft, a second accommodation groove for accommodating the guide shaft, a third accommodation groove for housing the speed shaft, and a fourth accommodation groove for accommodating the driven shaft. The drive gear is connected on the drive shaft, and the guide gear is coupled on the guide shaft and meshes with the drive gear. The speed change gear assembly includes a connection gear and at least two speed change gears. The driven gear assembly includes at least two driven gears corresponding to at least two speed change gears respectively. The control knob configured to drive the driven gear assembly to move upward and downward.

A control part of a control device includes a learning controller and a learning determination part. The learning controller performs learning control in which a correction amount of a resultant command is obtained, based on an oscillation phase obtained from an oscillation command and the resultant command, and the correction amount is added to the resultant command. The learning determination part determines whether or not the oscillation amplitude of the oscillation command is smaller than a predetermined threshold, and when the oscillation amplitude is smaller than the predetermined threshold value, the learning determination part both sets the oscillation command generated by an oscillation command generation part to zero and turns off the learning control or only turns off the learning control.

A control part of a control device includes a learning controller and a learning determination part. The learning controller performs learning control in which a correction amount of a resultant command is obtained, based on an oscillation phase obtained from an oscillation command and the resultant command, and the correction amount is added to the resultant command. The learning determination part determines whether or not the oscillation amplitude of the oscillation command is smaller than a predetermined threshold, and when the oscillation amplitude is smaller than the predetermined threshold value, the learning determination part both sets the oscillation command generated by an oscillation command generation part to zero and turns off the learning control or only turns off the learning control.