Douglas J Curtis

US Patent:

7762796, Jul 27, 2010

Filed:

Jul 23, 2004

Appl. No.:

10/565256

Inventors:

Donald Edwin Hargraves - Huntersville NC, US
Douglas Allan Curtis - Troutman NC, US

Assignee:

Hargraves Technology Corporation - Mooresville NC

International Classification:

F04B 39/10
F04B 53/10
F16K 15/14
F16K 15/16

US Classification:

417566, 417569, 417571, 137851, 137856

Abstract:

A valve assembly for a pump includes a pump chamber and a pump head having complementary recesses formed therein which cooperate to define a valve compartment including a pocket and an opposed seat. A flexible valve element is disposed between the recesses and adapted to move between a closed position against the seat which prevents fluid flow and an open position away from the valve seat which permits fluid flow. The dimensions of the valve compartment are selected to limit the movement of the valve element in the open position, which increases the pump efficiency and prevents damage to the valve element and/or valve overlap.

US Patent:

8096043, Jan 17, 2012

Filed:

Feb 8, 2010

Appl. No.:

12/701936

Inventors:

Donald Edwin Hargraves - Huntersville NC, US
Douglas Allan Curtis - Troutman NC, US

Assignee:

Hargraves Technology Corporation - Mooresville NC

International Classification:

H02K 15/14

US Classification:

29596, 2989806, 2989808, 310 90

Abstract:

A method of assembling a pump motor and preloading bearings of the motor including providing a housing, an end bell, first and second bearings each having a plurality of rolling elements disposed between an inner race and an outer race, a rotor assembly having a shaft, and a spring, securing the outer races to the housing and end bell, respectively, assembling the spring on the shaft, inserting the rotor assembly into the housing such that the spring bears against the inner race of the first bearing and the rotor assembly, attaching the end bell to the housing, and securing the inner race of each of the first and second bearings to the shaft.

US Patent:

20060181168, Aug 17, 2006

Filed:

Apr 14, 2004

Appl. No.:

10/550256

Inventors:

Donald Hargraves - Huntersville NC, US
Douglas Curtis - Troutman NC, US

International Classification:

H02K 5/16
H02K 5/00

US Classification:

310090000, 310089000

Abstract:

A electrical machine includes a housing assembly, first and second bearings mounted in the housing assembly, and a rotor assembly mounted in the bearings such that it has a predetermined amount of axial and radial play relative to the housing. A biasing element is disposed between one of the rotor assembly or the housing and one of the bearings. The biasing element urges the rotor assembly to a preloaded position which eliminates the axial and radial play. Each of the first inner and outer races and the second inner and outer races are secured to one of the rotor assembly or to the housing, such that the rotor assembly is retained in the preloaded position. The components of the electrical machine are chosen such that this preload is maintained over the operating temperature range of the machine.