Gearless motorized roller with variable frequency controller

• US 5,918,728 A
• Filed: 09/16/1997
• Issued: 07/06/1999
• Est. Priority Date: 09/16/1997
• Status: Expired due to Fees

• Current Assignee: Skarlupka Mfg., Inc.
• Original Assignee: Motion Systems LLC
• Inventors: Syverson, Charles D.
• Primary Examiner(s): Terrell, William E.
• Assistant Examiner(s): DEUBLE, MARK A
• Application Number:
  US08/931,593
• Time in Patent Office: 658 Days
• Field of Search: 198/784, 198/788, 310/179, 310/180, 310/24
• US Class Current: 198/788
• CPC Class Codes: B65G 13/06 Roller driving means
• CPC Class Codes: B65G 23/08 with self-contained driving mechanisms, e.g. motors and associated gearing
• CPC Class Codes: H02K 7/1016 Machine of the outer rotor type

Abstract

A drive roller for a conveyor is rotated by a brushless D.C. motor without any intervening gear reducer. The drove roller has a laminated metal stator with at least three windings external to the stator core. The stator is fixed to a rigid axially extending shaft which supports a roller tube and a permanent magnet rotor on bearings. The rotor is fixed to the roller tube and closely spaced from the stator. A variable frequency power supply controls the induced magnetic field in the stator to control the rotational speed of the drive roller.

Claims

1. A drive roller and roller controller for a roller conveyor comprising:

a shaft rigidly mounted to a conveyor support;

a stator having a core and twelve windings on the core, the stator being mounted about the shaft;

a roller tube surrounding the shaft and the stator, the roller tube having an interior, a first end and a second end, and an exterior surface having a diameter of 1.9 inches;

a first tube closure mounted to the roller tube first end, and a second tube closure mounted to the roller tube second end, the tube closures being rotatably mounted on the shaft to rotatably mount the roller tube on the shaft;

a permanent magnet rotor having sixteen poles which alternate North and South, the rotor being fixedly mounted to the roller tube interior and overlying and coaxial with the stator, the rotor and the stator forming a brushless three phase motor, with the rotor and the fixedly mounted roller tube being driven by changes in induced magnetic fields in the stator; and

a variable frequency controller in power supplying connection to the windings of the stator for controlling the rotation speed of the rotor.

2. The drive roller and roller controller of claim 1 wherein the motor core is about two inches long and produces about two lb-in of torque, and wherein the core contains about thirty-three laminations and the windings have about 130 turns of wire per coil.

3. The drive roller and roller controller of claim 1 wherein the motor core is about 4 inches long and produces about four lb-in of torque and wherein the core contains about sixty-six laminations and the windings consist of about 65 turns of wire per coil.

4. The drive roller and roller controller of claim 1 wherein the motor core is about 6 inches long and produces about six lb-in of torque and wherein the core has about 99 laminations and the windings consist of about 42 turns of wire per coil.

5. The drive roller and roller controller of claim 1 wherein the rotor permanent magnet is of the ferrite type.

6. The drive roller and roller controller of claim 1 wherein the variable frequency controller provides a voltage of about 24 volts.

7. A drive roller adapted for use in a roller conveyor and adapted to be driven with a variable frequency power supply, the drive roller comprising:

a shaft adapted for rigid mounting to a conveyor support;

a stator having a core and twelve windings on the core, the stator being mounted about the shaft;

a roller tube surrounding the shaft and the motor stator, the roller tube having an interior and having a first end and a second end and an exterior surface having a diameter of 1.9 inches;

two tube closures, one rigidly mounted to each of the first end and the second end of the roller tube, wherein the tube closures are rotatably mounted on the shaft so that the roller tube rotates on the shaft; and

a permanent magnet rotor having sixteen poles, which alternate North South, the rotor fixedly mounted to the roller tube interior and over and coaxial with the stator, the permanent magnet rotor and the stator forming a brushless D.C. motor, such that the rotor and fixedly mounted roller tube are driven by changes in induced magnetic fields in the stator.

8. The drive roller of claim 7 wherein the motor core is about two inches long and produces about two lb-in of torque, and wherein the core contains about thirty-three laminations and the windings consist of about 130 turns of wire per coil.

9. The drive roller of claim 7 wherein the stator core is about 4 inches long and produces about four lb-in of torque and wherein the core contains about sixty-six laminations and the windings consist of about 65 turns of wire per coil.

10. The drive roller of claim 7 wherein the stator core is about 6 inches long and produces about six lb-in of torque and wherein the core has about ninety-nine laminations and the windings consist of about 42 turns of wire per coil.

11. The drive roller of claim 7 wherein the rotor permanent magnet is of the ferrite type.

12. The drive roller of claim 7 wherein the core of the stator is constructed of laminations of mild steel.

13. A roller conveyor system comprising:

a frame;

a multiplicity of idler rollers positioned for rotation on the frame;

a plurality of drive rollers positioned on the frame, each drive roller having a rigid shaft fixed to the conveyor frame;

a stator having a core and at least three windings on the core, the stator being mounted about the shaft, the stator mounted about the rigid shaft;

a roller tube surrounding the shaft and the stator, and having a first and a second end and an interior;

two tube closures, one tube closure rigidly mounted to each of the first end and the second end of the roller tube, wherein the tube closures are rotatably mounted on the shaft, to rotatably mount the roller tube on the shaft; and

a permanent magnet rotor having a plurality of poles, the rotor fixedly mounted to the roller tube interior and overlying and coaxial with the stator, the permanent magnet rotor and the stator forming a brushless three-phase D.C. motor, with the rotor and connected roller tube being driven by changes in induced magnetic fields in the stator;

a plurality of variable frequency three-phase power supply controllers for controlling the rotation speed of each drive roller, each variable frequency controller connected to one of said multiplicity of drive rollers for controlling the rotation speed of the connected drive roller rotor; and

a programmable controller operably connected to the variable frequency controllers to control the speed of all the drive rotors.

14. The drive roller of claim 13 wherein the roller tube has an exterior surface having a diameter of 1.9 inches.