Girma G Desta

US Patent:

7701095, Apr 20, 2010

Filed:

Jul 30, 2007

Appl. No.:

11/881856

Inventors:

Daniel Gizaw - Belleville MI, US
David M. Erdman - Fort Wayne IN, US
Joseph E. Miller - Fort Wayne IN, US
Girma Desta - Suwanee GA, US

Assignee:

Danotek Motion Technologies - Ann Arbor MI

International Classification:

H02K 9/00

US Classification:

310 54, 310 52

Abstract:

The invention is a generator and cooling mechanism. The generator includes a rotor comprising a shaft with a skewed alignment of magnets on a ring, a stator of toothed laminations with coils wound around the teeth, and a housing with cooling chambers. The housing has annular subchambers arranged successively along the length of the generator in such a way that cooling fluid must flow to the opposite side of the generator to pass into the next chamber. Because the housing is highly heat conductive, this structure of annular subchambers increases the uniformity of the fluid temperature.

US Patent:

7750522, Jul 6, 2010

Filed:

Jul 18, 2007

Appl. No.:

11/779825

Inventors:

Daniel Gizaw - Belleville MI, US
David M. Erdman - Fort Wayne IN, US
Joseph E. Miller - Fort Wayne IN, US
Girma Desta - Suwanee GA, US

Assignee:

Danotek Motion Technologies - Ann Arbor MI

International Classification:

H02K 21/12

US Classification:

31015601, 31015647, 31015401

Abstract:

A direct-drive generator and assembly procedure for that generator include a permanent magnet assembly that is partitioned and assembled piece-by-piece after the rotor and stator have been attached. The magnets are attached to a plate in columns, and adjacent columns have a N-S orientation. The air gap between the rotor and stator is variable, and application of an input torque produces a first cogging torque in a first direction due to the variable air gap that offsets a second cogging torque in a second opposite direction.

US Patent:

7966716, Jun 28, 2011

Filed:

Jun 16, 2010

Appl. No.:

12/817018

Inventors:

Daniel Gizaw - Belleville MI, US
David M. Erdman - Fort Wayne IN, US
Joseph E. Miller - Fort Wayne IN, US
Girma Desta - Suwanee GA, US

Assignee:

Danotek Motion Technologies - Canton MI

International Classification:

H02K 15/03
H02K 1/30

US Classification:

29596, 31015626

Abstract:

A method for assembling a direct drive generator assembly includes the steps of placing a rotor over a stator, leaving a gap therebetween. A magnetic hub is assembled using adjacent columns of magnets having opposed orientation, and placed in the air gap. Application of an input torque to generate cogging torque in first direction that offsets coggery torque in second direction.

US Patent:

20080030088, Feb 7, 2008

Filed:

Jul 18, 2007

Appl. No.:

11/779811

Inventors:

Daniel Gizaw - Belleville MI, US
David Erdman - Fort Wayne IN, US
Joseph Miller - Fort Wayne IN, US
Girma Desta - Suwanee GA, US

International Classification:

H02K 11/00
H02K 5/18
H02K 9/18

US Classification:

310064000, 31006800B, 31006800C, 310089000

Abstract:

The present invention is an integrated brushless permanent-magnet motor with the circuit board controller in the same chamber as the rotor and stator. Including the circuit board controller in the same chamber as the rotor and stator allows for a more compact motor. The motor may include fins on its housing exterior such that the heat generated by the motor flows out of the housing through the fins, cooling the motor. The invention may also include features designed to reduce cogging.

US Patent:

59162465, Jun 29, 1999

Filed:

Oct 23, 1997

Appl. No.:

8/955711

Inventors:

Herman H. Viegas - Bloomington MN
Gary W. Wojciechowski - Minneapolis MN
Mark J. Buenz - Savage MN
Girma G. Desta - Richfield MN

Assignee:

Thermo King Corporation - Minneapolis MN

International Classification:

F17C 702

US Classification:

62 501

Abstract:

Both an system and method are provided for transferring liquid carbon dioxide from a storage tank pressurized at 300 psi to a truck-transportable tank pressurized at about 110 psi. The system includes an inlet conduit having a hose portion connected between the storage and transportable tanks for conducting a flow of liquid carbon dioxide therebetween, and a vent hose connected to the transportable tank for venting gaseous carbon dioxide. Pressure regulators are connected to the inlet and vent hoses, respectively. In operation, the pressure regulator connected to the inlet conduit reduces the pressure of the flow of liquid carbon dioxide entering the transportable tank from 300 psi to 175 psi, while the pressure regulator connected to the vent conduit maintains a back pressure of 110 psi in the transportable tank while the allowing the venting of gaseous carbon dioxide. Automatic shut-off and purging mechanisms are provided for shutting off the flow of liquid carbon dioxide when the transportable tank is filled, and purging the inlet hose. A muffler is connected to the outlet of the vent hose for reducing the noise associated with the venting of gaseous carbon dioxide.

US Patent:

6225720, May 1, 2001

Filed:

Nov 16, 1999

Appl. No.:

9/440897

Inventors:

Girma G. Desta - Richfield MN

Assignee:

Wood Group ESP, Inc. - Oklahoma City OK

International Classification:

H02K 708
F16C 3366

US Classification:

310 90

Abstract:

A self-lubricating bearing for use in submersible oil-filled motors is disclosed. The bearing comprises a bearing housing and is fixed against rotation. A bearing sleeve is disposed in the bearing housing. The bearing sleeve is fixed in the bearing housing, and has a slot disposed therethrough. The bearing housing has an inlet and an outlet defined therethrough that intersect the slot in the bearing sleeve. The bearing is disposed about a rotatable shaft in the motor. Rotation of the shaft will cause oil to be drawn in through the inlet so that the shaft and the bearing surface of the bearing sleeve are lubricated. Rotation will also cause oil drawn in through the inlet to be expelled through the outlet back into the motor so that there is a constant circulation of oil through the bearing to provide lubrication.