Patent Grant
10077105
Not applicable.
Not applicable.
In the event of engine failure, a helicopter can employ autorotation to execute a safe landing, wherein the main rotor system of the helicopter is turned by the action of air moving up through the rotor. This generates lift and drag to slow the descent of the helicopter. Autorotation can allow the helicopter to descend and land safely without the use of the main engine. Autorotation can be particularly useful for single engine helicopters.
In some embodiments of the disclosure, an autorotative assist system for a rotor helicopter is disclosed as comprising a transmission coupled to the rotor, an engine coupled to the transmission (via a drive shaft with a freewheeling unit allowing for free rotation of the rotor upon loss of engine power), and an autorotative assist unit couple to the transmission (typically independent of the engine primary drive system (e.g. drive shaft and/or free-wheeling unit) and/or without any intervening component or gearing such as the freewheeling unit), wherein the autorotative assist unit is operable to store energy during normal engine operation, and the autorotative assist unit is operable to drive the rotor through the transmission to provide supplemental autorotative assistance upon loss of engine power (e.g. when the engine rpm level falls below the rpm level of the rotor).
In other embodiments of the disclosure, a method of providing autorotative assistance for a rotor helicopter having an autorotative assist unit is provided that comprises, upon loss of engine power, placing the helicopter into autorotation, and providing autorotative assistance to the rotor from the autorotative assist unit (thereby driving the rotor as a supplement to autorotation).
In yet other embodiments of the disclosure, a method is disclosed for retrofitting a helicopter for improved autorotation capabilities, wherein the helicopter includes a rotor, a transmission having a generator off the transmission housing, and an engine, the method comprising replacing the generator on the transmission with a motor-generator, providing a high capacity/high discharge rate battery system, and electrically connecting the motor-generator to the battery system so that, during normal engine operation, the motor-generator charges the battery system, but upon loss of engine power, the motor-generator is operable to draw energy from the battery system to drive the rotor for autorotative assistance.
For a more complete understanding of the present disclosure and the advantages thereof, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description:
It should be understood at the outset that although an illustrative implementation of one or more embodiments are provided below, the disclosed systems and/or methods can be implemented using any number of techniques, whether currently known or in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, including the exemplary designs and implementations illustrated and described herein, but can be modified within the scope of the appended claims along with their full scope of equivalents.
In some cases, it can be desirable to provide enhancement or assistance to the autorotation of a helicopter in the event of engine failure. An autorotative assist unit can be operable to enhance the safety of the descent and landing of a helicopter using autorotation. The autorotative assist unit can provide supplemental power to the rotor system of a helicopter during autorotation, such as a landing flare of energy operable to slow descent of a helicopter right before landing, for example. A landing flare can be used to execute a safe landing during autorotation. Design criteria for helicopters can require the ability to complete autorotation from a certain density altitude, such as around 7,000 feet, for example. To meet the criteria, an autorotative assist unit can be used to enhance the autorotative capabilities of the helicopter.
Referring to
During autorotation, a pilot of the helicopter 120 can control the energy output from the autorotative assist unit 110 to the rotor 108, for example, deciding when to use the supplemental power from the autorotative assist unit 110 and/or how much of the available autorotative assist unit 110 power to use. The flight crew can be provided with an indication of the amount of energy stored in the autorotative assist unit 110. For example, the output of energy can be controlled automatically by the autorotative assist unit 110. In another example, a “landing flare” of energy from the autorotative assist unit 110 can be used to slow the descent of the helicopter 120 right before landing. In a further example, energy from the autorotative assist unit 110 can be used to slow the helicopter 120 throughout the descent and/or at the landing. Additionally, the energy input from the autorotative assist unit 110 can be used to stop descent, hover, level cruise, or possibly lift the helicopter 120 if necessary (for example, to traverse an obstacle). Several different methods can be used to input the energy from the autorotative assist unit 110 to the rotor 108 based on the conditions of the descent and landing and the abilities and decisions of the pilot of the helicopter 120.
In some embodiments, the autorotative assist unit 110 can respond to sensor input from sensors within the helicopter 120 to automatically provide autorotative assistance. Sensors can provide information comprising engine revolutions per minute (rpm), rotor rpm, descent rate, and/or altitude, as well as energy stored in the autorotative assist unit 110. For example, the autorotative assist unit 110 can be triggered to provide autorotative assistance when the rpm level of the engine 104 falls below the rpm level of the rotor 108. Autorotative assistance can also be controlled by a model or function executed by a controller coupled to the autorotative assist unit 110.
In some embodiments, the autorotative assist unit 110 can comprise an electric motor-generator, a battery system electrically coupled to the motor-generator operable to store and discharge energy, and a controller operable to control autorotative assist by communicating commands from a pilot and/or receiving sensor data. In another embodiment, the autorotative assist unit 110 can comprise a hydraulic pump-motor, a hydraulic accumulator in fluid communication with the hydraulic pump-motor operable to store and discharge energy, and a controller operable to control release of the energy stored in the hydraulic accumulator. In yet another embodiment, the autorotative assist unit 110 can comprise a mechanical power storage system, such as a flywheel or spring arrangement, for example.
Referring now to
The controller 216 can be operable to communicate commands to the motor-generator 212 for directing the stored power in the battery system 214 of the autorotative assist unit 210 to power the motor-generator 212 to drive the rotor 208. For example, the controller 216 can receive commands from a pilot of the helicopter, for example. In another example, the controller 216 can receive sensor input and, based on the sensor input, can automatically trigger the motor-generator 212 to provide autorotative assistance. Additionally, a combination of automatic and manual control of the autorotative assist unit 210 can be provided by the controller 216. In some embodiments, the energy input to the rotor 208 can be spread out during the descent and/or the energy can be used during the landing flare. This control of the energy output can be scheduled by the controller 216, it can be triggered by a pilot, or a combination of the two can be used. For example, the autorotative assist unit 210 can automatically put the helicopter in an autorotative state when the engine 204 fails, and the energy remaining after doing so can be used at the discretion of the pilot. In some embodiments, the autorotative assist unit 210 can be operable to provide about 80 hp for about 6-7 seconds. In other embodiments, the autorotative assist unit 210 can be operable to provide about 45 hp for about 3-4 seconds. In yet other embodiments, the autorotative assist unit 210 can be operable to provide about 45-80 hp for about 3-7 seconds. In some embodiments, the autorotative assist unit 210 can weigh about 62-64 pounds. Typically, the weight of such an autorotative assist unit can be less than the additional weight that would have to be added to the rotor to achieve rotational inertia for comparable autorotation landing performance.
Some embodiments of the disclosure include methods 240, shown in
Referring now to
Referring now to
Some embodiments of the disclosure can include methods, as shown in
Referring now to
Some embodiments of the disclosure can include methods, shown in
As has been described above and shown in the figures, certain embodiments of the disclosure include a shim that is used to bond a component to a bearing. The shim can have an elastic modulus value that is lower than an elastic modulus value of the component being bonded to the bearing. In such a case, as torsional strain is applied to the component, the shim absorbs a portion of the torsional strain. This reduces an amount of torsional strain experienced by an adhesive layer. Accordingly, since the amount of torsional strain in the adhesive layer is reduced, the adhesive layer can be less likely to fail during operation and can require less maintenance. Additionally, the use of a shim can be advantageous in that it can replace custom molded bearings and components, which can have long lead times and be difficult to assemble and replace.
At least one embodiment is disclosed and variations, combinations, and/or modifications of the embodiment(s) and/or features of the embodiment(s) made by a person having ordinary skill in the art are within the scope of the disclosure. Alternative embodiments that result from combining, integrating, and/or omitting features of the embodiment(s) are also within the scope of the disclosure. Where numerical ranges or limitations are expressly stated, such express ranges or limitations should be understood to include iterative ranges or limitations of like magnitude falling within the expressly stated ranges or limitations (e.g., from about 1 to about 10 includes, 2, 3, 4, etc.; greater than 0.10 includes 0.11, 0.12, 0.13, etc.). For example, whenever a numerical range with a lower limit, Rl, and an upper limit, Ru, is disclosed, any number falling within the range is specifically disclosed. In particular, the following numbers within the range are specifically disclosed: R=Rl+k*(Ru−Rl), wherein k is a variable ranging from 1 percent to 100 percent with a 1 percent increment, i.e., k is 1 percent, 2 percent, 3 percent, 4 percent, 5 percent, . . . , 50 percent, 51 percent, 52 percent, . . . , 95 percent, 96 percent, 97 percent, 98 percent, 99 percent, or 100 percent. Unless otherwise stated, the term “about” shall mean plus or minus 10 percent of the subsequent value. Moreover, any numerical range defined by two R numbers as defined in the above is also specifically disclosed. Use of the term “optionally” with respect to any element of a claim means that the element is required, or alternatively, the element is not required, both alternatives being within the scope of the claim. Use of broader terms such as comprises, includes, and having should be understood to provide support for narrower terms such as consisting of, consisting essentially of, and comprised substantially of. Accordingly, the scope of protection is not limited by the description set out above but is defined by the claims that follow, that scope including all equivalents of the subject matter of the claims. Each and every claim is incorporated as further disclosure into the specification and the claims are embodiment(s) of the present invention.
This application is a divisional application of and claims priority to U.S. patent application Ser. No. 14/934,477 filed on Nov. 6, 2015, now U.S. Pat. No. 9,522,730, which is a continuation application of and claims priority to U.S. patent application Ser. No. 13/834,215 filed on Mar. 15, 2013, now U.S. Pat. No. 9,180,964. The entire contents of the foregoing patent applications are hereby incorporated by reference for all purposes.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3027704 | Dmitroff | Apr 1962 | A |
| 3260313 | Reuther | Jul 1966 | A |
| 3362255 | De Rocca et al. | Jan 1968 | A |
| 3455182 | Kelley | Jul 1969 | A |
| 4046335 | Osberger | Sep 1977 | A |
| 4609165 | Logan et al. | Sep 1986 | A |
| 5100080 | Servanty | Mar 1992 | A |
| 8283796 | Certain | Oct 2012 | B2 |
| 8464980 | Certain | Jun 2013 | B2 |
| 8469306 | Certain | Jun 2013 | B2 |
| 8727271 | Salyer | May 2014 | B2 |
| 8757542 | Hopdjanian et al. | Jun 2014 | B2 |
| 8939399 | Kouros et al. | Jan 2015 | B2 |
| 9045223 | Connaulte et al. | Jun 2015 | B2 |
| 9180964 | Smith et al. | Nov 2015 | B2 |
| 9522730 | Smith | Dec 2016 | B2 |
| 20020145076 | Alford | Oct 2002 | A1 |
| 20090113871 | Certain | May 2009 | A1 |
| 20090145998 | Salyer | Jun 2009 | A1 |
| 20090320460 | Peterson | Dec 2009 | A1 |
| 20100013223 | Certain | Jan 2010 | A1 |
| 20110024555 | Kuhn, Jr. | Feb 2011 | A1 |
| 20110121127 | Certain | May 2011 | A1 |
| 20120025032 | Hopdjanian | Feb 2012 | A1 |
| 20130134253 | Carter, Jr. | May 2013 | A1 |
| 20130134264 | Carter, Jr. et al. | May 2013 | A1 |
| 20140034781 | Kouros | Feb 2014 | A1 |
| 20140346283 | Salyer | Nov 2014 | A1 |
| 20160059957 | Smith et al. | Mar 2016 | A1 |
| Number | Date | Country |
|---|---|---|
| 102008014404 | Oct 2009 | DE |
| 1247736 | Oct 2002 | EP |
| 2327625 | Jun 2011 | EP |
| 2703292 | Mar 2014 | EP |
| 1219457 | Jan 1971 | GB |
| Entry |
|---|
| European Patent Office, European Search Report for Application No. 13171571.6 dated Oct. 17, 2013, 3 pp. |
| European Patent Office, Communication pursuant to Article 94(3) EPC for Application No. 13171571.6 dated Jan. 12, 2014, 4 pp. |
| European Patent Office, Communication pursuant to Article 94(3) EPC for Application No. 13171571.6 dated Oct. 30, 2013, 5 pp. |
| European Patent Office, European Search Report for Application No. 15194261.2 dated Feb. 5, 2016, 4 pp. |
| European Patent Office, Communication pursuant to Article 94(3) EPC for Application No. 15194261.2 dated Feb. 18, 2016, 5 pp. |
| Priuschat, “Comparing the Prius v. Honda hybrid idle-stop feature”, Nov. 2007 http:/priuschat.com/threads/comparing-the-prius-v-honda-hybrid-idle-stope-feature.39401/. |
| Number | Date | Country | |
|---|---|---|---|
| 20170096219 A1 | Apr 2017 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14934477 | Nov 2015 | US |
| Child | 15383458 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13834215 | Mar 2013 | US |
| Child | 14934477 | US |
