Abstract: An impeller and at least a portion of a cooperating peripheral volute may be integrated into, and preferably are integrally injection molded with, concentric outer rotor and inner stator assemblies, respectively, to achieve a low profile precision impeller mechanism based on an improved brushless d.c. motor with low length (L) to diameter (D) ratio and suitable for use in a variety of other applications. In one practical embodiment of such a motor, a rotating cap has an inner circumference which is molded about an outer ferromagnetic back ring that in turn supports a permanently magnetized ring shaped rotor magnet having a number of poles of alternating polarity defined about its inner circumference and separated by a relatively small cylindrical air gap from the outwardly projecting radially oriented selectively magnetized poles of a fixed stator assembly. In one exemplary embodiment, the rotor may have 8 poles and the stator may have 9 poles.
Type:
Application
Filed:
February 27, 2006
Publication date:
June 29, 2006
Applicants:
ResMed Limited, Servo Magnetics, Inc.
Inventors:
Leslie Hoffman, Barton Kenyon, David Sears
Abstract: An impeller and at least a portion of a cooperating peripheral volute may be integrated into, and preferably are integrally injection molded with, concentric outer rotor and inner stator assemblies, respectively, to achieve a low profile precision impeller mechanism based on an improved brushless d.c. motor with low length (L) to diameter (D) ratio and suitable for use in a variety of other applications. In one practical embodiment of such a motor, a rotating cap has an inner circumference which is molded about an outer ferromagnetic back ring that in turn supports a permanently magnetized ring shaped rotor magnet having a number of poles of alternating polarity defined about its inner circumference and separated by a relatively small cylindrical air gap from the outwardly projecting radially oriented selectively magnetized poles of a fixed stator assembly. In one exemplary embodiment, the rotor may have 8 poles and the stator may have 9 poles.
Type:
Grant
Filed:
March 5, 2004
Date of Patent:
March 14, 2006
Assignees:
ResMed Limited, Servo Magnetics, Inc.
Inventors:
Leslie C. Hoffman, Barton J. Kenyon, David B. Sears
Abstract: An impeller and at least a portion of a cooperating peripheral volute may be integrated into, and preferably are integrally injection molded with, concentric outer rotor and inner stator assemblies, respectively, to achieve a low profile precision impeller mechanism based on an improved brushless d.c. motor with low length (L) to diameter (D) ratio and suitable for use in a variety of other applications. In one practical embodiment of such a motor, a rotating cap has an inner circumference which is molded about an outer ferromagnetic back ring that in turn supports a permanently magnetized ring shaped rotor magnet having a number of poles of alternating polarity defined about its inner circumference and separated by a relatively small cylindrical air gap from the outwardly projecting radially oriented selectively magnetized poles of a fixed stator assembly. In one exemplary embodiment, the rotor may have 8 poles and the stator may have 9 poles.
Type:
Application
Filed:
March 5, 2004
Publication date:
January 20, 2005
Applicants:
SERVO MAGNETICS, INC., ResMed, Ltd.
Inventors:
Leslie Hoffman, Barton Kenyon, David Sears
Abstract: A d.c. controller pump includes electronic control mechanisms that permit regulated control within a fluid flow system. A pump head is coupled to a housing allowing the fluid to infiltrate the region surrounding a permanent magnet rotor. Stator windings and control electronics fixed to a plurality of printed circuit boards are isolated from the fluid by means of a solid body that encapsulates the stator windings and seals the rear of the cavity. Hall effect sensor-generators and other assemblies are fixed within the solid body to enhance integrity and reduce parts count. Associated electronics includes a readily-removable circuit board for housing auxiliary electronic functions. The board is mounted in parallel at the rear of the pump housing with boards of sensor and controller electronics. The auxiliary function electronics pump configurations enable both fixed and variable speed operation in accordance with fluid flow system design and parameters.