BALANCER
A rotating object balancer may include an insert configured for securing to an object and having a chamber for placement of balancing elements and a curable solution, a rotational system configured to rotate the object at high-speed, a monitoring system for monitoring vibrations of the object rotating at high-speed, and a curing tool configured for curing the curable solution when the object has reached a balanced state. A method of balancing may be performed by the balancer and a balanced object may be created by the balancer.
The present application claims priority to U.S. Provisional Application No. 61/917,193 filed on Dec. 17, 2013 entitled Balancer, the content of which is hereby incorporated by reference herein in its entirety.
FIELD OF THE INVENTIONThe present disclosure relates generally to balancing. More particularly, a system and method for balancing objects that rotate by adjusting the moment of inertia of the objects is described. Still more particularly, the present disclosure relates to dynamically balancing rotating objects such as propellers, fans, wheels, hubs, motors, sheaves, pulleys, and other rotating objects.
BACKGROUNDThe Federal Aviation Administration (FAA) is mandated to open U.S. airspace for the commercial use of unmanned aerial vehicles (UAVs) by 2015. It is expected that any company or individual that wishes to use UAVs commercially will need to fill out a safety flight operations certificate (SFOC) that will need to be approved by the FAA each time they plan on operating a UAV. It is anticipated that the SFOC document will include a flight plan and certification that the UAV meets all safety requirements defined by the FAA. It appears that one requirement will be that all propellers are dynamically balanced to limit vibration in the aircraft. Vibration due to propeller imbalance limits the effectiveness of on-board instrumentation (i.e., a high resolution camera would take unclear photos and video) and possibly causes mechanical failure of the aircraft.
Current methods for balancing propellers include suspending the propellers at their center and allowing them to hang vertically. Where the propeller has a tendency to turn or rotated tape may be added to the propeller to avoid disrupting the aerodynamics of the propeller while attempting to rely on the weight of the tape to balance the propeller. The propeller may also be hung horizontally and where the propeller has a tendency to turn or rotate, additional tape may be added. In addition, vibrations in a propeller may be monitored or sensed during rotation and then the propeller may be brought to a stop to adjust the propeller. This process may be reiterated until a balanced propeller is achieved. A similar approach is often used for balancing tires in the automotive industry, for example. Given the anticipated large number of UAV and other propellers that are to be in services as early as 2015, current approaches to balancing propellers or other objects are unduly time consuming and not cost effective.
BRIEF SUMMARY OF THE INVENTIONIn one or more embodiments, a rotating object balancer may include an insert configured for securing to an object and having a chamber for placement of balancing elements and a curable solution. The balancer may include a rotational system configured to rotate the object at high-speed. The balancer may also include a monitoring system for monitoring vibrations of the object rotating at high-speed. The balancer may also include a curing tool configured for curing the curable solution when the object has reached a balanced state.
In one or more embodiments, a method of balancing an object may include arranging balancing elements on the object such that the balancing elements are free to move within a region. The method may also include rotating the object at high-speed and monitoring the object for a balanced condition. The method may also include fixing the position of the balancing elements when the object is in a balanced condition and while the object is rotating.
In one or more embodiments, a rotationally balanced object may include a body portion and a cavity arranged within the body portion. The object may also include a balancing element arranged within the cavity portion and a cured or curable substance arranged within the cavity. The cured or curable substance may at least partially surround the balancing element and be configured for securing the position of the balancing element when the substance is in a cured state.
The present application, in one or more embodiments, includes a discussion of a propeller and/or insert adapted for dynamic balancing in addition to a system and method for balancing propellers or other rotating objects. The propeller or other rotating object may include a hollow chamber with free moving weights arranged therein. In the case of a propeller, the chamber may be arranged in or around the hub of the propeller. The propeller with the chamber may be rotated at high speeds and the free movement of the weights may allow the weights to naturally find a balanced arrangement or position within the chamber. The chamber may also include a curable medium in which the free moving weights are suspended. While the propeller is in motion and in a balanced condition, the curable medium may be cured such as with an ultraviolet light device, for example.
The present application is, thus, inventive and advantageous for several reasons. First, while the moment of inertia of a rotating object may be more drastically modified by adjusting the mass closer to the perimeter of the rotating object, the present approach adjusts the mass more proximate to the axis of rotation with surprisingly effective results. In addition, the present application moves away from manual static balancing and iterative dynamic balancing and employs a single iteration dynamic approach. It does so by first employing an automatic balancing approach that allows the modified propeller to find a balanced condition. Secondly, it provides a way to fix that balanced condition while the propeller is rotating. As such, the present device and method provides an extremely efficient approach to balancing of propellers or other rotating objects. It is to be appreciated that while the focus of the present application may be on propellers, a similar approach may be provided for balance a wide range of objects including wheels, rims, pulleys, sheaves, motors, spindles, armatures, and other rotating and/or non-rotating objects.
It is to be further appreciated that while a particular rotating object in the form of a propeller 100 has been described, most any rotating object may be provided with a similar balancing feature. In some embodiments, for example, a wheel or other rotating object may have an insert 102 similar to the one described. In other embodiments, a more permanent portion of the rotating object may be dedicated for balancing. That is, the mentioned chamber 112 may be a part of the object itself rather than part of an insert 102 for use with or attachment to the object. Still further, while the presently described insert 102 is arranged near the center of rotation of the object, chambers 112 and balancing elements 116 may be positioned more radially outward than described.
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While not show in detail, a top portion 218 may be provided that is similar to the receiver portion 214 except that the top portion 218 may have a protruding lug or shaft 236 for engaging and/or supporting a rotating object in lieu of having a receiving bore 226. However, like the receiver portion 214, the top portion 218 may include a pair of straddling tabs that each include a bore for receiving the pegs on the upper portion of the central block 216. The top portion may be configured to be arranged in an inverted position relative to the receiver portion 214 for the universal switch 208.
In one embodiment, the clamp 202 may secure the block 250 in place. The top/bottom plates 246 may be secured thereto with differing orientations such that the square extrude on the universal switch 208 may be inserted into the square opening formed by the crossing rectangular slots. The bracket 206 may be secured to the block 250 through the openings in the corners of the top/bottom plate 246. The bottom cage 210B may be secured to the bracket 206 and the female end of the universal switch 208 may extend upward through the bracket 206 and into the bottom of the cage 210. The motor bracket 240 may be secured to the female end of the universal switch 208 by inserting the rectangular extrude into the female receiver 226 in the switch 208. Springs 262, 264 may be provided to stabilize the switch 208 within the cage 210. The motor may be secured to the motor bracket 240 with screws and the propeller 100 may be mounted on the drive shaft of the motor. The upper portion of the cage 210A may be positioned on the lower portion 210B to close the system. Still other arrangements of the several elements of the system may be provided.
As mentioned above, the device may be used to balance a propeller or other object or rotating object by performing a method (300).
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The balanced propeller may be measured to identify the levels of imbalance that remain. These measurements may be made throughout a wide range of rotational speeds to identify imbalance amounts at various speeds. A balance report may be generated for purposes of maintaining the report with the propeller such that a later user may understand the balance properties of the propeller. It is to be appreciated that identification elements such as bar codes, QR codes, RFID tags and the like may also be included as part of the propeller and the balance report may be saved to a database and associated with identification element of the propeller allowing easy and secure access to balance information for large number of balanced propellers or objects.
While the present disclosure has been described with reference to various embodiments, including preferred embodiments, it will be understood that these embodiments are illustrative and that the scope of the disclosure is not limited to them. Many variations, modifications, additions, and improvements are possible. More generally, embodiments in accordance with the present disclosure have been described in the context of particular embodiments. Functionality may be separated or combined in blocks differently in various embodiments of the disclosure or described with different terminology. These and other variations, modifications, additions, and improvements may fall within the scope of the disclosure as defined in the claims that follow.
Claims
1. A rotating object balancer, comprising:
- an insert configured for securing to an object and having a chamber for placement of balancing elements and a curable solution;
- a rotational system configured to rotate the object at high-speed;
- a monitoring system for monitoring vibrations of the object rotating at high-speed; and
- a curing tool configured for curing the curable solution when the object has reached a balanced state.
2. The balancer of claim 1, wherein the curing tool comprises an ultraviolet light emitting device.
3. The balancer of claim 2, wherein the curing tool comprises a heating element.
4. The balancer of claim 1, wherein the object is a propeller.
5. The balancer of claim 4, wherein the insert is configured for engaging the hub of the propeller.
6. The balancer of claim 1, wherein the rotational system comprises a universal switch configured to isolate vibrations from a drive system so as to avoid affecting vibration of the object.
7. The balancer of claim 6, wherein the universal switch comprises a drive receiving portion, a central portion pivotable relative to the drive receiving portion about a first axis, and a top portion pivotable relative to the central portion about a second axis.
8. The balancer of claim 7, wherein the drive receiving portion defines a longitudinal axis and the first axis and second axis are substantially perpendicular to the longitudinal axis.
9. The balancer of claim 8, wherein the first and second axes are substantially perpendicular to one another.
10. The balancer of claim 9, wherein further comprising a cage for surrounding the object during rotation.
11. The balancer of claim 1, wherein the chamber is substantially annular in shape and includes a substantially round cross-section.
12. The balancer of claim 11, wherein the balancing elements comprise ball bearings.
13. The balancer of claim 11, wherein the balancing elements are surrounded by the curable solution within the chamber.
14. The balancer of claim 13, wherein the curable solution is curable by exposure to ultraviolet light.
15. A method of balancing an object, comprising:
- arranging balancing elements on the object such that the balancing elements are free to move within a region;
- rotating the object at high-speed;
- monitoring the object for a balanced condition; and
- fixing the position of the balancing elements when the object is in a balanced condition and while the object is rotating.
16. The method of claim 15, wherein the region comprises a chamber and arranging balancing elements on the object comprises placing the objects in a chamber.
17. The method of claim 16, wherein fixing the position of the balancing elements comprises exposing the object to ultraviolet light.
18. A rotationally balanced object, comprising:
- a body portion;
- a cavity arranged within the body portion;
- a balancing element arranged within the cavity portion; and
- a cured or curable substance arranged within the cavity at least partially surrounding the balancing element and configured for securing the position of the balancing element when the substance is in a cured state.
19. The object of claim 18, wherein the substance is curable using ultraviolet light.
20. The object of claim 19, wherein the substance is curable using heat.
21. The object of claim 18, wherein the substance is a two part material curable by mixing.
22. The object of claim 18, wherein the body portion comprises a base portion and an insert or attachment.
23. The object of claim 18, wherein the cavity is arranged in the insert or attachment.
Type: Application
Filed: Dec 17, 2014
Publication Date: Jun 18, 2015
Inventors: Samuel Collette (Eagan, MN), David Johnson (Hager City, WI), Paul Schreier (Maplewood, MN), Devyani Sharma (Blaine, MN), Andrew Smith (Shoreview, MN)
Application Number: 14/573,533