ORBITAL OSCILLATION FAN
A precessing fan system includes a fan blade connected to a precessing drive train. The precessing drive train is connected to a first support at one end and pivotably connected to a second support at another end. The precessing drive train includes a single motor having a drive shaft driving both the fan blade and orbital gearing. The orbital gearing causes precession of the drive shaft and is connected to the first support. The orbital gearing includes a gear reduction that is coupled to the drive shaft, a pinion that is coupled to the gear reduction and a ring gear coupled to the pinion. The ring gear is connected to the first support. A planetary gearing system is used for the pinion and the ring gear.
This application claims priority to Provisional Patent Application Ser. No. 61/425,112, filed on Dec. 20, 2010, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTIONVarious embodiments relate to a portable environmental device having a fan to propel air along a moveable axis. In particular, embodiments relate to fans being able to propel air along a precessing fan axis.
BACKGROUND OF INVENTIONOscillating fans have long been available to propel air along an axis that can sweep an expanse along an arc in one plane, the axis often moving at a fixed height relative to a supporting surface. For instance, U.S. Pat. No. 6,830,433 to Birdsell et al., the contents of which are incorporated herein by reference, discloses a tiltable apparatus for the distribution of air that includes a fan unit having a first and second portion, where the second portion is pivotable relative to the first portion about a common axis. Such conventional oscillating fans provide intermittent ventilation to a larger area compared to a stationary fan, which provides constant ventilation to a smaller area.
U.S. Pat. No. 5,720,594 to Snow, the contents of which are incorporated herein by reference, describes a fan that provides oscillation simultaneously in two axes, or in one selected axis. Two oscillation mechanisms are provided, each having its own oscillation motor and each being selectively operable independently of the other. Optionally, the main fan motor may be employed to power one of the oscillation mechanisms.
Conventional oscillating fans are not effective in providing ventilation in an expanse perpendicular to the plane of the swept arc. Ventilation in this direction may be desirable in order to ventilate a larger spatial volume, or for diffusing a scent, mist, or the like over the larger spatial volume. Fans such as that of Snow are large, heavy and expensive at least because two or more motors are needed. Thus, there is a need for a small, lightweight and inexpensive fan that provides a ventilation sweep over both a horizontal and vertical expanse of a spatial volume.
SUMMARY OF THE INVENTIONVarious embodiments of the present invention provide a small, lightweight and inexpensive fan that provides ventilation over both a horizontal and vertical expanse of a spatial volume. More specifically, a fan axis orbits in a conical manner that can be selectively engaged or disengaged. A motor drives both the fan and the orbital motion of the fan axis. Embodiments of the invention can be used in any device that propels air, such as a fan, a space heater or a humidifier.
In one aspect a precessing fan system is disclosed that includes a fan blade connected to a precessing drive train. The precessing drive train is connected to a first support and pivotably connected to a second support. The precessing drive train includes a motor having a drive shaft driving both the fan blade and orbital gearing. The orbital gearing causes precession of the drive shaft and is connected to the first support.
In preferred embodiments the orbital gearing includes a gear reduction that is coupled to the drive shaft, a pinion that is coupled to the gear reduction and a ring gear coupled to the pinion. The ring gear is connected to the first support. In a specific embodiment a planetary gearing system is used, in which the pinion and the ring gear are components of the planetary gearing system. In particularly preferred embodiments the motor is the only motor in the fan system. In other embodiments a clutch is provided for disengaging the orbital gearing so as to stop precession of the fan blades.
In another aspect a method is provided to cause precession of a fan blade. A shaft is rotated that is pivotably coupled to a support. The rotation of the shaft is used to rotate a fan blade. Further, the rotation of the shaft is used to cause rotation of a pinion around a fixed ring gear. The shaft is coupled to the pinion so that deflections induced by movement of the pinion around the ring gear are transmitted to the shaft as a precession of the shaft.
The above and still further objects, features and advantages of the present invention will become apparent upon consideration of the following detailed description of specific embodiments thereof, especially when taken in conjunction with the accompanying drawings wherein like reference numerals in the various figures are utilized to designate like components, and wherein:
Various embodiments provide an improved fan to disperse or move air within a volume. Preferred embodiments are usable in any device that propels air, such as a fan, a space heater, a humidifier or the like. A specific preferred embodiment includes a portable environmental device housing, a base, and an internal assembly. The internal assembly includes fan blades coupled to a drive train. The drive train includes a single motor coupled to an orbital gearing system that causes precession of the drive train, and hence of the fan blades, around the axis of rotation of the fan blades. The motor, such as an electric motor, has a drive shaft having a first end coupled to the fan blades and a second end coupled to a gear reduction mechanism. The gear reduction mechanism couples the drive shaft to a pinion through one or more gears which reduce the rotation rate of the drive shaft, which in turn produces the rotation rate of the pinion. Coupling of the gearing reduction to the pinion may be by way of a gear shaft, or by way of direct coupling of the pinion to the gearing of the gearing reduction. A gear shaft, if used, has a distal end, upon which is fixedly attached the pinion. The pinion is coupled to a ring gear, planetary gear, or the like on a surface other than the motor's rear surface, allowing the motor shaft, fan blades and drive shaft to pivot and to trace a cone shape. The gear reduction mechanism, pinion and ring or planetary gear together form the orbital gearing system. A pivot surface is coupled to the drive train, preferably near a center of gravity of the pivotable parts.
To facilitate the precession of the drive train 210, the second support for the drive train 210 can be a pivot point. The pivot point can be provided by a pivot coupled, for example, between the casing of the motor 202 and an internal surface 209 of fan housing 208, by pivotably supporting a portion of shaft 201, or by any other suitable means known in the art. As a result of the rigid connection of the orbital gearing to the housing 208 via the ring gear 206, and the pivotal connection of the drive train 210 at another end, displacements of the pinion 204 are transmitted to the drive shaft 201, causing precession of the drive shaft 201, and hence to the fan blades 205.
In operation of the embodiment of
Embodiments of the present invention may be used as standalone systems or as sub-component systems that are incorporated into other appliances that move air during their operation. For instance, embodiments of the present invention may be incorporated into a heater. Optionally, a heating element of the heater may also oscillate along with elements described in
While there have been shown, described, and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions, substitutions, and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit and scope of the invention. For example, it is expressly intended that all combinations of those elements and/or steps which perform substantially the same function, in substantially the same way, to achieve the same results are within the scope of the invention. Substitutions of elements from one described embodiment to another are also fully intended and contemplated. It is also to be understood that the drawings are not necessarily drawn to scale, but that they are merely conceptual in nature. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.
Claims
1. A precessing fan system comprising:
- a fan blade; and
- a precessing drive train coupled to the fan blade and to a first support, the first support supporting the precessing drive train, the precessing drive train comprising: a motor having a drive shaft coupled to the fan blade; and orbital gearing coupled to the first support and to the drive shaft;
- wherein the drive shaft drives both the fan blade and the orbital gearing, and the orbital gearing causes precession of the drive shaft.
2. The precessing fan system of claim 1 wherein the orbital gearing comprises:
- a gear reduction coupled to the drive shaft;
- a pinion coupled to the gear reduction; and
- a ring gear coupled to the pinion, the ring gear connected to the first support.
3. The precessing fan system of claim 2 wherein the pinion and the ring gear are components of a planetary gearing system.
4. The precessing fan system of claim 1 wherein the precessing drive train is further pivotably connected to a second support.
5. The precessing fan system of claim 1 wherein the motor is the only motor in the fan system.
6. The precessing fan system of claim 1 further comprising a clutch for disengaging the orbital gearing.
7. The precessing fan system of claim 1 further comprising a housing, the fan blade and precessing drive train disposed within the housing, and wherein the first support is provided by the housing.
8. The precessing fan system of claim 7 wherein the precessing drive train is further pivotably connected to a second support provided by the housing.
9. A method for providing precession of a fan blade, the method comprising:
- rotating a shaft that is pivotably coupled to a support;
- using the rotation of the shaft to rotate a fan blade; and
- using the rotation of the shaft to cause rotation of a pinion around a fixed ring gear, wherein the shaft is coupled to the pinion.
10. The method of claim 8 further comprising coupling the shaft to the pinion through a gear reduction mechanism.
11. A precessing fan system comprising:
- a housing;
- a motor disposed within the housing and movably connected to the housing;
- a shaft extending from two sides of the motor and rotationally driven by the motor;
- a fan blade disposed within the housing and coupled to one end of the shaft; and
- orbital gearing fixed to the housing and coupled to the other end of the shaft to induce precession of the shaft.
12. The precessing fan system of claim 11 wherein the orbital gearing comprises:
- a gear reduction coupled to the drive shaft;
- a pinion coupled to the gear reduction; and
- a ring gear coupled to the pinion, the ring gear fixed to the housing.
13. The precessing fan system of claim 12 wherein the pinion and the ring gear are components of a planetary gearing system fixed to the housing.
14. The precessing fan system of claim 11 wherein the motor is pivotably connected to the housing.
15. The precessing fan system of claim 11 wherein the motor is the only motor in the fan system.
16. The precessing fan system of claim 11 further comprising a clutch for disengaging the orbital gearing from the motor.
Type: Application
Filed: Dec 20, 2011
Publication Date: Jun 21, 2012
Inventors: Walter Birdsell (Marlborough, MA), William Henderson (Holden, MA), Mark McMenemy (Northborough, MA)
Application Number: 13/330,786
International Classification: F04D 25/08 (20060101);