Linear-actuated press machine having multiple motors and clutch system for multi-speed drive functionality

A method of operating a linear-actuated press machine for forming a part, the press machine comprises a first motor, a second motor, a linear actuator having a rotatable screw that remains linearly stationary and a nut that translates vertically along the rotatable screw male-female thread mechanism, a press ram coupled to the nut of the linear actuator and for holding a tool, and a clutch coupled to the first motor, the method comprising:

• rotating the rotatable screw of the linear actuator with the second motor to move the nut along the rotatable screw and advance the press ram toward the part in a first low-force and high-speed condition, the clutch being partially or fully disengaged so as to reduce the rotational movement on the first motor while the press ram is advancing toward the part in the first low-force and high-speed condition;
• in response to the press ram being a distance “X” from the part, (i) reducing the rotational drive speed provided by the second motor to reduce the linear velocity of the press ram and (ii) monitoring the rotational drive speed with a second sensor;
• during the reducing and while the clutch remains partially or fully disengaged, (i) operating the first motor and (ii) sensing a first motor rotational speed with a first sensor;
• in response to the first motor rotational speed being a value that should provide approximately the same rotational drive speed at the linear actuator as the rotational drive speed measured by the second sensor, engaging the clutch to provide a high-force and low-speed condition to the press ram from the first motor;
• by use of the press ram in the high-force and low-speed condition, forming the part with the tool;
• after the forming of the part, retracting the tool from the part by use of at least one of the first motor and the second motor;
• and
• subsequent to the retracting, (i) increasing the velocity of the press ram in a direction away from the formed part by use of the second motor to create a second low-force and high-linear-speed condition, and (ii) partially or fully disengaging the clutch so as to limit the rotational movement on the first motor during the second low-force and high-linear-speed condition.

A method of operating a linear-actuated press machine for forming a part, the press machine comprises a first motor, a second motor, a linear actuator having a male-female thread mechanism, a press ram coupled to linear actuator and for holding a tool, and a clutch coupled to the first motor, the method comprising:

• driving the linear actuator with the second motor to advance the press ram toward the part in a first low-force and high-speed condition, the clutch being partially or fully disengaged so as to reduce the rotational movement on the first motor while the press ram is advancing toward the part in the first low-force and high-speed condition;
• in response to the press ram being a distance “X” from the part, (i) reducing the rotational drive speed at the linear actuator provided by the second motor to reduce the linear velocity of the press ram and (ii) monitoring the rotational drive speed at the linear actuator with a second sensor;
• during the reducing and while the clutch remains partially or fully disengaged, (i) operating the first motor and (ii) sensing a first motor rotational speed with a first sensor;
• in response to the first motor rotational speed being a value that should provide approximately the same rotational drive speed at the linear actuator as the rotational drive speed measured by the second sensor, engaging the clutch to provide a high-force and low-speed condition to the press ram from the first motor;
• by use of at least 100 tons of force from the press ram in the high-force and low-speed condition, forming the part with the tool;
• after the forming of the part, retracting the tool from the part by use of at least one of the first motor and the second motor;
• and
• subsequent to the retracting, (i) increasing the velocity of the press ram in a direction away from the formed part by use of the second motor to create a second low-force and high-linear-speed condition, and (ii) partially or fully disengaging the clutch so as to limit the rotational movement on the first motor during the second low-force and high-linear-speed condition.

A press machine for forming a part, comprising:

• a moveable press ram configured to apply force to form the part;
• an actuator for moving the moveable press ram by use of a male-female thread mechanism for producing a linear movement of the moveable press ram, the actuator including at least one actuator sprocket coupled to the male-female thread mechanism;
• a first motor drive system for producing a low-speed high-force linear movement to the moveable press ram via the actuator, the first motor drive system including a first motor for driving a first motor sprocket, a clutch, a first belt system coupling the first motor sprocket to the at least one actuator sprocket;
• a second motor drive system for producing a high-speed low-force linear movement to the moveable press ram via the actuator, the second motor drive system including a second motor for driving a second motor sprocket and a second belt system coupling the second motor sprocket to the at least one actuator sprocket;
• and
• a platform to which a first base plate of the first motor is mounted and to which a second base plate of the second motor is mounted, at least one of the platform, the first base plate and the second base plate including slots for adjusting the positions of the first motor or the second motor relative to the platform to providing tension to the first belt system or the second belt system;
• wherein, in response to the high-speed low-force linear movement of the second motor drive system to advance or retract the press ram relative to the part, the clutch of the first motor drive system is at least partially disengaged;
• and
• wherein, in response to the low-speed high-force linear movement of the first motor drive system to form the part, the clutch of the first motor drive system is operationally engaged to transfer torque from the first motor to the at least one actuator sprocket of the linear actuator via the first belt system.