Methods are currently available for converting a motor rotation to a bi-directional linear motion wherein a complex interface is interconnected with the motor shaft to provide the linear movement.
Two early arrangements are described within U.S. Pat. No. 3,641,828 entitled “Rotary-Linear Motion Converter” and within U.S. Pat. No. 4,324,148 entitled “Rotary/Linear Motion Converter Assembly”.
A more recent arrangement for converting motor rotation is the use of a linear actuator whereby a lead screw is connected with the motor shaft during the motor manufacture, per se.
One example of a lead screw for a linear actuator is described within U.S. Pat. No. 7,086,303 entitled “Lead Screw for Linear Actuator and Method of Manufacturing Same”.
U.S. Pat. No. 6,422,101 entitled “Reinforced Lead Screw with Springless Ani-Backlash Nut” and U.S. Pat. No. 7,552,657 entitled “Long-Span Lead Screw Assembly with Anti-Backlash Nut” describe the arrangement of the lead screw relative to a motor rotor.
Whereas the lead screws currently employed require supplemental means for coupling to the motor shaft, or specific assembly during the motor manufacture, it would be more convenient and economically feasible to attach the lead screw directly to a motor shaft after motor manufacture, per se.
One purpose of the instant invention, accordingly, is to provide an integrated linear actuator arrangement that could be attached to the motor shaft after the motor has been completely assembled.
A linear actuator arrangement consists of an extended lead screw terminating at one end via a conical section and a threaded rod. A conical aperture within one end of a customized rotor shaft abuts a threaded aperture formed therein.
As shown in
In further accordance with the invention, as shown in
The combined rotor shaft-lead screw assembly 21 is now depicted in
Although the attachment of the lead screw 10 to the rotor shaft 14 is shown prior to completion of the stepper motor, this is for purposes of clarity. In actuality, the rotor shaft 14 is part of the complete stepper motor assembly (not shown) and the lead screw 10 is assembled therein after such assembly.
A linear actuator arrangement has herein been described whereby a simple adjustment to the rotor shaft of a stepper motor and the like is adjusted to receive a plurality of sized lead screws without having to design and adjust each and every stepper motor to accommodate each and every sized lead screw, as described earlier.