Abstract: A motor assembly 10 includes a DC motor 12 having a motor housing 14 defining a stator, a rotor assembly 18 supported for rotational movement with respect to the stator, and a shaft 22 coupled to the rotor assembly for rotation about an axis of rotation A. The assembly 10 includes a supporting structure 30 carrying the motor and decoupling structure 32. The decoupling structure 32 mounts the motor housing 14 to the supporting structure 30 in a manner to provide a certain natural frequency of the motor in torsion around the axis of rotation A of the shaft 22 while providing natural frequencies higher than the certain natural frequency for degrees of freedom of the motor other than torsion. The assembly 10 also includes pivot structure 44 and 46, associated with the supporting structure and the motor defining a pivot between the motor and the supporting structure with a center of the pivot being aligned with the axis of rotation.

Abstract: A motor control system 10 includes an engine cooling module 14 including a DC motor 12. The system includes a switch 18 constructed and arranged to be controlled by a pulse width modulated (PWM) signal 26. The switch 18 is operatively associated with the DC motor to control current to the DC motor and thus control the speed of the DC motor. A controller 20 is operatively associated with the switch. The controller is constructed and arranged to select periods, of a limited-pool of frequencies each being less than 500 Hz, from a pseudo-random sequence of periods and to send the selected periods to the switch, thereby controlling noise and vibration of the module.

Abstract: A low tone axial flow fan structure includes a hub 12; an inner fan 14 including a number of inner blades 16 attached to the hub and extending radially outwardly to a first circumferentially extending blade support structure 18; and an outer fan 20 including a number of outer blades 22 attached to the first circumferentially extending blade support structure 18 and extending radially outwardly to a second circumferentially extending blade support structure 20. The number of outer blades defines an outer fan blade passing order. The number of inner blades ensures creation of blade passing orders or multiple of said blade passing orders within one blade passing order of the outer fan blade passing order so as to provide masking of the outer fan blade passing order.

Abstract: A low tone axial flow fan structure includes a hub 12; an inner fan 14 including a number of inner blades 16 attached to the hub and extending radially outwardly to a first circumferentially extending blade support structure 18; and an outer fan 20 including a number of outer blades 22 attached to the first circumferentially extending blade support structure 18 and extending radially outwardly to a second circumferentially extending blade support structure 20. The number of outer blades defines an outer fan blade passing order. The number of inner blades ensures creation of blade passing orders or multiple of said blade passing orders within one blade passing order of the outer fan blade passing order so as to provide masking of the outer fan blade passing order.

Abstract: An engine cooling assembly 10 includes an electric motor 12, a fan 14 driven by the electric motor, and a shroud 16 at least partially surrounding the fan. First, resilient decoupling structure 20 mounts the motor to the shroud in a manner to isolate vibration between the motor and the shroud. Second, flexible decoupling structure 22 is associated with the shroud and is constructed and arranged to mount the shroud to the shroud mounting structure in a manner to isolate vibration between the shroud and the shroud mounting structure when the shroud is coupled to the shroud mounting structure.

Abstract: A turbomachine for moving air includes a shroud 12 disposed about an axis A. The shroud 12 has a pair of opposing faces 14 and 16 defining a gap 18 therebetween. The opposing faces are disposed generally transversely with respect to the axis. A rotor assembly 13 is mounted for rotation about the axis. The rotor assembly has a plurality of blades 22 with tips of the blades being coupled to an annular band 30. At least a portion 32 of the annular band is disposed in the gap 18. Seal structure 36 extends from each opposing face of the shroud and into the gap to reduce swirl and minimize air leakage across the gap.

Abstract: A turbomachine for moving air includes a shroud 12 disposed about an axis A. The shroud 12 has a pair of opposing faces 14 and 16 defining a gap 18 therebetween. The opposing faces are disposed generally transversely with respect to the axis. A rotor assembly 13 is mounted for rotation about the axis. The rotor assembly has a plurality of blades 22 with tips of the blades being coupled to an annular band 30. At least a portion 32 of the annular band is disposed in the gap 18. Seal structure 36 extends from each opposing face of the shroud and into the gap to reduce swirl and minimize air leakage across the gap.

Abstract: A turbomachine for moving air comprising includes a shroud disposed about a longitudinal axis and a rotor assembly mounted for rotation about the longitudinal axis. The rotor assembly has a plurality of blades and tips of the blades are coupled to an annular band. The annular band is disposed with respect to the shroud so as to define a gap extending continuously between an outer surface of the annular band and an inner surface of the shroud. A seal structure extends from the inner surface of the shroud and into the gap. The seal structure has a density sufficient to reduce swirl in recirculating airflow and to minimize air leakage across the gap.