GB2609488A

GB2609488A - Gearbox temperature regulation system and method

Info

Publication number: GB2609488A
Application number: GB2111327.9A
Authority: GB
Inventors: Elogab Osama; Elogab Zachary
Original assignee: Ogab Ltd
Current assignee: Ogab Ltd
Priority date: 2021-08-05
Filing date: 2021-08-05
Publication date: 2023-02-08
Anticipated expiration: 2041-08-05
Also published as: WO2023012461A1; GB2609488B

Abstract

The present invention provides a vortex tube 3 for supplying a stream of air 5, 7 at a temperature substantially different from ambient temperature toward an output 13, 15 adjacent a gearbox to regulate its temperature. The vortex tube may be a Ranque-Hilsch vortex tube that separates the incoming compressed air 1 into a cold air stream 5 and a hot air stream 7 in order to respectively cool or heat the gearbox. Valves 23, 25 may be used to control the supply of the cooling or heating air. The valves may be controlled by a controller in response to a signal from a gearbox temperature sensor.

Description

GEARBOX TEMPERATURE RF.GULATTON SYSTEM AND METT TOD The present invention relates generally to a gearbox temperature regulation system and a method of regulating the temperature of a gearbox and finds particular, although not exclusive, utility in helicopter gearboxes.

Although gearboxes are designed to operate over a wide range of temperatures, problems can still occur if a gearbox is too cold, or if a gearbox overheats. Conventional approaches to cooling gearboxes involve the supply of a suitable amount of lubricant to act as a heat sink or coolant; if overheating is still a problem, using a greater quantity of lubricant and moving it toward and away from the gearbox more quickly is often tried.

To mitigate the effects of a cold gearbox, often merely an alternative lubricant is chosen to be more effective at lower temperatures.

According to a first aspect of the present invention, there is provided a gearbox temperature regulation system, comprising: an outlet configured to he disposable adjacent to a gearbox; a duct arranged to convey air to the outlet; and a vortex tube configured to supplying a stream of air at a temperature substantially different from ambient temperature into the duct, for conveyance to the outlet.

The outlet may be configured to introduce air into the gearbox, or immediately adjacent the gearbox; however, in alternative arrangements the outlet may be spaced from the gearbox. 't he outlet may comprise a plurality of outlets, which may be configured to introduce air into a plurality of respective locations.

The duct may comprise a plurality of ducts, and may comprise a hose. The hose/duct should allow a relatively unrestricted airflow from the inlet. larger diameter (i.e. cross-sectional area for non-circular cross-sections) hose/duct allows for increased airflow, and airflow typically increases as a square of the diameter.

The vortex tube may comprise a Ranque-T Tilsch vortex tube.

The vortex tube may comprise: an inlet arranged to collect air at a first temperature, and at a pressure subst2uatially above atmospheric pressure; a high temperature outlet configured to supply a first stream of air at a second temperature substantially above the first temperature; and a low temperature outlet configured to supply a second stream of air at a third temperature substantially below the first temperature.

The inlet rnay be arranged to collect air from the Front of the vehicle so that ram pressure of the vehicle's movement will provide high pressure air into the Alternatively, a pump (e.g. an air pump) may supply air into the inlet. The pump may be electrically driven, or mechanically linked to the vehicle's crank shaft and/or rotor blades.

However, in preferred embodiments, the pump may be driven by a turbo. That is, exhaust gases may drive a turbo that in turn is used to drive the pump for providing high pressure air into the inlet.

the duct may be configured to supply the first stream of air to a respective subset of the plurality of outlets. 't he duct may be configured to supply the second stream of air to a farther respective subset of the plurality of outlets. The duct may be configured to supply the first and second stream of air to the same outlet / plurality of outlets, and/or an overlapping subset of the plurality of outlets. Each subset of the plurality of outlets may be arranged to provide a respective air stream to a respectively predetermined portion Of the gearbox.

The vortex tube may he configured to supplying the first stream of air it the second temperature into the duct, for convey2uace to the outlet.

ha this way, the gearbox temperature regulation system could be employed to heat up the gearbox in very cold conditions (tor instance in which the gearbox may freeze). the gearbox temperature regulation system may be provided with a further outlet for conveying the first and/or second stream of air at the second and/or third temperature, respectively, to an alternative system. For example, the alternative may comprise an active drag reduction system, an internal cabin heater and/or air conditioning system.

The vortex tube may be configured to supplying the second stream of air at the third temperature into the duct, for conveyance to the outlet.

The gearbox temperature regulation system may further comprise a controller configured to control supply of the stream of air From the vortex tube to the outlet.

the gearbox temperature regulation system may further comprise a temperature sensor configured to monitor a temperature of the gearbox and the controller configured to control supply of the stream of air from the vortex tube to the outlet in response thereto.

In this way, the temperature sensor and controller may control the gearbox temperature regulation system to cool the gearbox when at risk of over-heating, and/or heat the gearbox when at risk of freezing.

The gearbox temperature regulation system may be configured to connect to an active drag reduction system. bar example, the vortex tube may be arranged to supply a hot stream of air and/or a cool stream of air to an active drag reduction system, and the gearbox temperature regulation system may be configured to redirect such hot and/or cold streams of air from the active drag reduction system in response to a temperature determined by the temperature sensor above/below one or more threshold temperatures.

An active drag reduction system may he employed on a vehicle configured such that, when moving at a speed above a predetermined threshold speed, at least one turbulent and/or low pressure region is fanned adjacent to the vehicle. An active drag-reduction system may be configured to reduce the at least one turbulent and/or low pressure region when activated, for instance by injecting warm air and/or cool air toward the turbulent/low pressure region.

An active drag reduction system may comprise at least one propelling nozzle located adjacent to the at least one region; and a system for providing gas to the at least one nozzle for expulsion into the at least one region, for instance as described in W02016/139472.

An active drag-reduction system may comprise: at least one first fluid outlet located on the vehicle adjacent to the at least one region; at least one second fluid outlet located on the vehicle adjacent to the at least one region and spaced from the at least one first fluid outlet; and a fluid supply system configured to: provide fluid at a first pressure and/or first ejection velocity to the at least one first fluid outlet; and provide fluid at a second pressure and/or second ejection velocity to the at least one second fluid outlet, wherein the second pressure and/or second ejection velocity is greater than the first pressure and/or first ejection velocity, respectively.

the gearbox temperature regulation system may comprise a forced induction system for the vortex tube (for instance, at the inlet). The forced induction system may comprise: a first compressor configured to produce a first stream of gas: an air multiplier arranged to receive the first stream of gas and eject the first stream of gas over a Coandli surface, the air multiplier configured to entrain ambient air with the ejected first stream of gas to produce a second stream at-gas.

In this w" a mass of air being introduced into the vortex tube can be increased, by virtue of the air multiplier upstream.

The first compressor may comprise a pump, for instance an air pump. The first stream of gas may comprise a first stream of air. the first stream of gas may be above ambient, and may comprise a comprise a compressed air stream.

the air multiplier may comprise an air amplifier, jf he air multiplier may comprise a device which use a first amount of compressed air to generate a second flow of air larger than the first amount. The air multiplier may operate by taking advantage of an aerodynamic effect known as "the Cc/an& effect". The Goan& surface may be a curved surface. The air multiplier may increase airflow by up to 40 times, in particular a factor of between Sand 18 times.

The air multiplier may comprise a plurality of air multipliers. For example, a first air multiplier may be located at a first location along the passage, and a second air multiplier may be located at a second location along the passage.

The air multiplier may take the first stream of gas and eject it though an air outlet adjacent to a "Coandr surface, thereby entraining surrounding air. In particular, the air outlet may be configured to eject the gas substantially over the Com& surface.

The Coanda surface may be located around an internal perimeter of the passage. In particular, the Goan& surface may form a closed loop around the internal perimeter of the passage. Similarly, the air outlet may be located around an internal perimeter of a passage. In particular, the air outlet may form a closed loop around the internal perimeter of the passage. The air outlet may comprise a ring nozzle.

The first stream of gas may have a pressure of between 1bar and 4har, in particular between 2bar and 3bar, more particularly approximately 2.5bar.

The first stream of gas may be conveyed to the air multiplier via a feed line.

The first stream of gas may have a temperature below ambient. in this way, air being supplied to the air multiplier may be more dense than ambient air. Tiowever, in alternative arrangements the compressed air stream may have a temperature above ambient, or a temperature that is substantially equal to ambient.

the second stream of gas may be a combination of the first stream of gas and the entrained ambient air.

the forced induction system may further comprise a screen for filtering the ambient air prior to its entrainment by the air multiplier, in this way, damage to the air multiplier from grit and/or particulates can be prevented The screen may comprise a grille and/or mesh.

According to a second aspect of the present invention, there is provided a gearbox system comprising: a gearbox; and the gearbox temperature regulation system of the first aspect.

According to a third aspect of the present invention, there is provided a vehicle comprising: a gearbox: and the gearbox temperature regulation system of the first aspect.

the vehicle may be a helicopter. Alternatively, or additionally, the vehicle may be an aeroplane, car, van, lorry, motorcycle or other similar vehicle.

According to a fourth aspect of the present invention, there is provided a method of regulating the temperature of a gearbox, the method comprising: providing a gearbox; providing the gearbox temperature regulation system of the first aspect; and controlling supply of the stream of air from the vortex tube to the outlet.

The above and other characteristics, features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. This description is given for the sake of example only, without limiting the scope of the invention. The reference figures quoted below refer to the attached drawings.

Figure 1 is a schematic representation of a gearbox temperature regulation system.

the present invention will be described with respect to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. Each drawing may not include all of the features of the invention and therefore should not necessarily be considered to be an embodiment of the invention. Tn the drawings, the sfze of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other sequences than described or illustrated herein.

Moreover, the terms top, bottom, over, under and the like in the description and the claims are used for descriptive purposes and not necessarily for describing relative positions. it is to be understood that the terms so used are interchangeable under appropriate circumstances and that operation is capable in other orientations than described or illustrated herein.

It is to be noticed that the term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof Thus, the scope of the expression "a device comprising means A and 13" should not be limited to devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B. Reference throughout this specification to "an embodiment" or "an aspect" means that a particular feature, structure or characteristic described in connection with the embodiment or aspect is included in at least one embodiment or aspect of the present invention. Thus, appearances of the phrases "in one embodiment", "in an embodiment", or "in an aspect" in various places throughout this specification are not necessarily all referring to the same embodiment or aspect, but may refer to different embodiments or aspects. Furthermore, the particular features, structures or characteristics of any embodiment or aspect of the invention may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments or aspects.

Similarly, it should be appreciated that in the description various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Moreover, the description of any individual drawing or aspect should not necessarily be considered to be an embodiment of the invention. Rather, as the following claims reflect, inventive aspects lie in fewer than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention. Furthermore, while some embodiments described herein include some features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form yet further embodiments, as will be understood by those skilled in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

in the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practised without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.

In the discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying bemeen the more preferred and the less preferred of said alternatives, is relf preferred to said less preferred value and also to each value lying bemeen said less preferred value and said intermediate value.

't he use of the term "at least one" may mean only one in certain circumstances.

the principles of the invention will now be described by a detailed description of at least one drawing relating to exemplary features of the invention. It is clear that other arrangements can be configured according to the knowledge of persons skilled in the art without departing from the underlying concept or technical teaching of the invention, the invention being limited only by the terms of the appended claims.

Figure 1 shows a gearbox temperature regulation system that receives high pressure air at an inlet I, which is supplied to a vortex tube 3. As is well-known, the high-pressure air is split into a cold stream 5 and a hot stream 7, each of which is conveyed by respective ducting 9,11 to respective outlets 13,15.

Each outlet is directed toward a gearbox 17. In some arrangements, the outlets 13, 15 may be directed toward the same part of the gearbox; however, in alternative arrangements, the outlets 13, 15 may be directed toward different parts of the gearbox.

Between the vortex tube 7 and each outlet 13, 15, is provided a respective valve 23, 25. The valves 23, 25 are shown as generic valves, but it is to be appreciated that in some arrangements these valves 23,25 are configured as diverters; that is, merely diverting the cold stream 5 and hot stream 7 along different ducts (not shown), so as not to cause unnecessary back-pressure at the vortex tube 3

Claims

CLAIMSA gearbox temperature regulation system, comprising: an outlet configured to be disposable adjacent to a gearbox; a duct arranged to convey air to the outlet; and a vortex tube configured to supplying a stream of air at a temperature substmtially different from ambient temperature into the duct, for conveyance to the outlet.
2. The gearbox temperature regulation system of claim 1, wherein the vortex tube 10 comprises: an inlet arranged to collect air at a first temperature, and at a pressure substantially above atmospheric pressure; a high temperature outlet configured to supply a first stream of air at a second temperature substantially above the first temperature; and a low temperature outlet configured to supply a second stream of r at a third temperature substantially below the first temperature.
3. The gearbox temperature regulation system of claim 2, wherein the vortex tube is configured to supplying the first stream of air at the second temperature into the duct for conveyance to the outlet.
4. The gearbox temperature regulation system of claim 2 or claim 3, wherein the vortex tube is configured to supplying the second stream of air at the third temperature into the duct, for conveyance to the outlet.
The gearbox temperature regulation system of any preceding claim, further comprising a controller configured to control supply of the stream of air from the vortex tube to the outlet.
6. The gearbox temperature regulation system of &Mil 5, further comprising a temperature sensor configured to monitor a temperature of the gearbox and the controller configured to control supply of the stream of air from the vortex tube to the outlet in response thereto.
7. A gearbox system comprising: a gearbox; and the gearbox temperature regulation system of any preceding claim.
8. A vehicle comprising: a gearbox; and the gearbox temperature regulation system of any one of claims 1 to 6.
9. A method of regulating the temperature of a gearbox, the method comprising: providing a gearbox; providing the gearbox temperature regulation system of any one of claims 1 to 6; and controlling supply of the stream of air from the vortex tube to the outlet.