FIELD OF THE INVENTION
Various 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 INVENTION
Oscillating 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 INVENTION
Various 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.
BRIEF DESCRIPTION OF THE DRAWINGS
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:
FIG. 1 is a front left elevated perspective view in accord with an embodiment of the invention;
FIG. 2 is a front right elevated perspective sectional view in accord with an embodiment of the invention;
FIG. 3 is a right sectional view in accord with an embodiment of the invention;
FIG. 4 is an exploded schematic view in accord with an embodiment of the invention; and
FIG. 5 is a schematic view of a planetary gear usable with an embodiment of the invention.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
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.
FIG. 1 shows a front left elevated perspective view of fan 100, which is an embodiment of the invention. Visible in FIG. 1 are housing 101 having an opening 102, a protective grill 103 that covers the opening 102, and fan blades 104 situated behind protective grill 103. In operation, the fan blades 104 rotate by way of a drive shaft driven by a drive train having a single motor to propel air through the protective grill 103 and into the area surrounding fan 100. Optionally, the drive shaft may precess around a pivot point, such that an axis of the drive shaft traces a periodic path, which may be a regular or symmetric path describing a conic shape or the like. Protective grill 103 can be affixed to housing 101, such that the grill 103 is substantially unmovable. Alternatively, protective grill 103 may be affixed to a component, such as the motor, that moves as the drive shaft precesses, so that the grill 103 also moves.
FIG. 2 shows a front right elevated perspective sectional view of a fan embodiment 200. Elements of fan 200 include a drive shaft 201 extending from a precessing drive train 210 and coupled to fan blades 205. One end of the precessing drive train 210 is rigidly connected to a first support, which in this embodiment is provided by the housing 208 of the fan 200, while another end is pivotably connected to a second support, which can also be provided by the housing 208, to facilitate precession of the drive shaft 201. The precessing drive train 210 includes a single motor 202 that rotates the drive shaft 201. The drive shaft 201 extends from one side of the motor 202 to couple to the fan blades 205 to rotate the fan blades 205, and further extends from another side of motor 202 to drive orbital gearing that causes the drive shaft 201 to describe a cone-like motion. The orbital gearing can include, for example, a gear reduction 203 coupled via a pinion 204 to a ring gear 206. Gear reduction 203 uses the drive shaft 201 to provide an output torque on an output shaft 207 that has a rotational speed that is slower than that of the drive shaft 201. This output shaft 207 drives the pinion 204 that, in turn, engages with the ring gear 206. The ring gear 206 is rigidly attached to housing 208. As pinion 204 rotates, it traces a circular path around an inner circumference of ring gear 206, thereby causing the drive train 210, excepting the ring gear 206, to precess and thus causes the fan blades 205 to precess as well.
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.
FIG. 3 shows a right sectional view of fan embodiment 300. The rotating mechanisms of fan 300 are elevated along a front side 301 of fan 300 relative to a rear side 302 of fan 300. This configuration reduces a problem such that, during a portion of the conical motion, the propelled air would otherwise be propelled into the surface supporting the fan, thereby reducing the effectiveness of the fan and causing unwanted movement of items on the supporting surface. As elements of fan 300 orbit through the conical surface shape, elevation of front side 301 causes fan 300 to propel air above or parallel to the supporting surface, rather than into the supporting surface, during substantially all parts of the orbit. As shown in FIG. 3, the drive shaft 301, motor 302 and orbital gearing 309, which includes gear reduction 303, a pinion (not shown) and ring gear 306, form a precessing drive train that describes an orbital movement dictated by the orbital gearing 309. This drive train can be pivotably supported at any suitable location. For example, as shown in FIG. 3, the orbital gearing 309 can be supported by the fan housing via the ring gear 306, while the drive shaft 301 can be pivotably supported by a bushing 307 or the like disposed between the fan blades and the motor 302 and rigidly connected to the fan housing.
FIG. 4 shows an exploded schematic view of another fan embodiment 400. Motor 401 drives drive shaft 402, which extends from opposing ends of motor 401. On one side of motor 401, drive shaft 402 is coupled to fan blades 404. On another side of motor 401, drive shaft 402 is coupled to gear reduction 403. Any suitable gearing reduction means know in the art may be employed for gear reduction 403, such as by way of meshed spur gears with differing gearing ratios, a worm drive or the like. Gear reduction 403 provides an output gear shaft 405, which rotates at a rate proportionately slower than drive shaft 402 in accordance with the effective gearing ratio of gear reduction 403, and which output shaft 405 is coupled at a distal end to pinion 406. In another embodiment, drive shaft 402 could couple directly to pinion 406 through a worm gear or the like. Pinion 406 engages with the inner circumference of a ring gear 407. Ring gear 407 is secured to a first support of the fan, such as a fan housing (not shown in FIG. 4). An optional clutch 411, shown in dashed lines in FIG. 4, engages with the output gear shaft 405 of the gear reduction 403. Gear reduction 403, output shaft 405, optional clutch 411, pinion 406 and ring gear 407 form orbital gearing that cause drive shaft 402 to precess. Motor 401 is coupled to a pivot joint that provides a second support, represented in the exploded form of FIG. 4 as a ball 408 which couples to matching socket 409. Socket 409 is secured to a surface 410 of the fan housing.
In operation of the embodiment of FIG. 4, motor 401 coupled to the orbital gearing provide a disengagable precessing drive train that selectively causes the fan blades to precess around a cone-shaped path. Specifically, motor 401 rotates drive shaft 402 at a relatively fast rate of rotation, thereby rotating fan blades 404 at the same rate. Gear reduction 403 includes a set of gears which rotate the gear shaft 405 at a reduced rate of rotation that is predetermined by the gear ratio of gear reduction 403. Clutch 411 selectively disengages motor 401 from ring gear 407, for example by breaking the transmission of the rotation of output gear shaft 405 to pinion 406, or by moving pinion 406 such that it no longer engages with ring gear 407, thereby disengaging the orbital gearing. Clutch design is known to persons of skill in the art and any suitable design can be employed. Clutch 411 is selectively actuated by a user of the fan in order to stop or start the conical orbital motion of the drive shaft 402, and hence of the fan blades 404. As pinion 406 rotates, it engages with ring gear 407, causing pinion 406 to move around the inner circumference of ring gear 407. Pinion 406 and ring gear 407 may be implemented as a planetary gear system, as described in connection with FIG. 5 below. As pinion 406 moves in this way, output gear shaft 405 and drive shaft 402 precess, with a pivot point determined by ball 408 and socket 409. The drive shaft 402, motor 401 and orbital gearing 403, 405, 406, 407, 411 together form the selectively precessing drive train that drives the fan 404 and that selectively describes an orbital movement dictated by the orbital gearing 403, 405, 406, 407, 411. This drive train can be pivotably supported at any suitable location or locations.
FIG. 5 shows a schematic view of a planetary gearing system usable with an embodiment of the invention. Ring gear 501, which can be mounted on the fan housing, encloses a rotatable sun gear 503 in the center and one or more planetary gears 502 that are in contact with both the inner circumferential surface of ring gear 501 and the outer circumferential surface of sun gear 503. One of the planetary gears 502 is configured to serve as a pinion 506 for an embodiment precessing drive train as described above. As pinion 506 is rotated by the output shaft of the reduction gearing, for instance in a clockwise direction, planetary gears 502, driven by sun gear 503, travel in a counterclockwise direction around the inner circumferential surface of ring gear 501, with the sun gear 503 rotating in a clockwise direction. Sandwiched between the ring gear 501 and the sun gear 503, the pinion 506 is firmly, though orbitally, held in place.
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 FIG. 5. In another embodiment, embodiments of the present invention may be incorporated into a mist humidifier, such that the fan 404 and motor 401 orbit over a wick filter, or are positioned in a path where humidified air is introduced into the fan. Embodiments of the present invention may be usable for all known methods of portable humidifiers.
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.
Patent Application
20120156064
