Servo motor controlled hydraulic pump unit for tube end forming equipment

摘要

Systems and methods for providing tube end forming equipment or machines that utilize the advantage of hydraulic power without having the constant noise, heat, and energy usage associated with traditional hydraulic power units. The end forming machine includes a hydraulic pump that is operated only when a demand from the system for oil pressure/flow is present. This is accomplished by providing a synchronous servo motor and servo drive coupled to a fixed displacement hydraulic pump. The oil pressure of the system is monitored to detect when the pressure drops below a preset value to provide closed-loop control of the servo motor. The servo motor is controlled to rotate the hydraulic pump at the required speed (up to the maximum RPM of the motor/pump combination) as necessary to obtain the desired system pressure during the tube end forming process.

主权项

1. An apparatus for altering the shape of an end of a tube using an end forming tool, the apparatus comprising:
a hydraulic actuator operatively couplable to the end forming tool and configured to move the end forming tool into contact with the end of the tube to alter the shape thereof; a hydraulic pump operatively coupled to the hydraulic actuator through a hydraulic circuit comprising hydraulic fluid, the hydraulic pump being configured to generate flow and pressure of the hydraulic fluid in the hydraulic circuit to drive the hydraulic actuator; a servo motor operatively coupled to the hydraulic pump and configured to drive the hydraulic pump; a servo drive coupled to the servo motor and operative to control the speed or torque of the servo motor which in turn controls the flow rate or pressure of the hydraulic fluid in the hydraulic circuit; a pressure transducer operatively coupled to the hydraulic circuit and the servo drive, the pressure transducer being configured to monitor the hydraulic pressure of the hydraulic circuit and to provide pressure feedback information to the servo drive that is used by the servo drive to control the speed or torque of the servo motor; and a controller operatively coupled to the servo drive and the hydraulic actuator, the controller being configured to control the position and movement of the end forming tool by receiving position feedback information from the hydraulic actuator and sending control commands to the servo drive indicative of system pressure; wherein the hydraulic pump is a fixed displacement hydraulic pump.