Patent Description:
A gearbox is a component of a drive system in a vehicle of any time (ground-based or aircraft). A typical gearbox includes one or more input shafts, one or more output shafts and gearing. The gearing is operably coupled between the one or more input shafts and the one or more output shafts whereby rotation of the one or more input shafts can be transmitted to the one or more output shafts. In many cases, the gearing can be provided to change the gear ratio between the one or more input shafts and the one or more output shafts. This gear ratio can be adjustable and/or selectable.

Gearboxes often require shrouds and lube jets. Shrouds are useful in protecting lubrication flow in gearbox sump areas and in reducing power loss by managing windage. Protecting lubrication flow is particularly helpful at mesh points where gears mesh with one another. The lube jets are positioned to direct a jet of lubrication fluid at or near the meshing gears to prevent overheating and damage.

In conventional gearboxes, the shrouds and lube jets are separate components and are not combined due to costs and general construction history. However, since separate shrouds and lube jets each have their own associated machining costs, extra hardware, o-rings, etc., the overall costs, complexities and weights of gearboxes can all be high. Moreover, in some cases, a shape of the shroud in a gearbox might be compromised to allow for a nearby lube jet to have access to the corresponding gears.

<CIT> discloses a lubrication system for a vehicle transmission. The lubricant is held in a circuit supported by gravity and lubricant guidance components. For a first, a second and a third lubrication area, there are a first, a second and a third lubricant channel with drip openings to the respective lubrication areas arranged underneath.

According to the invention, a shroud is provided and includes the features of claim <NUM>.

In accordance with additional or alternative embodiments, the first and second curved sections are disposable proximate to meshing gears within a gearbox.

In accordance with additional or alternative embodiments, the first and second curved sections have respective curvatures that conform to curvatures of the meshing gears.

In accordance with additional or alternative embodiments, the main interior channel is chargeable with lubricant whereby the lubricant is communicated into and through the at least one of the first and second jetting interior channels.

In accordance with additional or alternative embodiments, the lubricant is communicated into and through the first jetting interior channel at sufficient pressure to form a longitudinal lubricant jet upon exiting the inwardly facing aperture.

In accordance with additional or alternative embodiments, the lubricant is communicated into and through the second jetting interior channel at sufficient pressure to form a sidelong lubricant jet upon exiting the laterally facing aperture.

In accordance with additional or alternative embodiments, the shroud further includes mountings by which the first and second curved sections are mountable to a housing.

In accordance with additional or alternative embodiments, the shroud further includes plugs to plug open ends of the main interior channel and the at least one of the first and second jetting interior channels.

According to the invention, a gearbox is provided and includes the features of claim <NUM>.

In accordance with additional or alternative embodiments, the lubricant is communicated into and through the first jetting interior channel at sufficient pressure to form a longitudinal lubricant jet that impinges on the meshing of the meshing gears upon exiting the inwardly facing aperture.

In accordance with additional or alternative embodiments, the lubricant is communicated into and through the second jetting interior channel at sufficient pressure to form a sidelong lubricant jet that impinges on the bearing of the one of the meshing gears upon exiting the laterally facing aperture.

In accordance with additional or alternative embodiments, the shroud further includes mountings by which the first and second curved sections are mountable to the housing.

According to an aspect of the invention, a shroud forming method is provided as claimed in claim <NUM>.

In accordance with additional or alternative embodiments, the method further includes mounting the shroud to the housing and charging the interior channels with the lubricant.

In accordance with additional or alternative embodiments, the assembling of the shroud includes additive manufacturing.

In accordance with additional or alternative embodiments, the assembling of the shroud includes one of casting and brazing.

In accordance with additional or alternative embodiments, the assembling of the shroud further includes drilling the interior channels and plugging open ends of the interior channels.

Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with the advantages and the features, refer to the description and to the drawings.

As will be described below, a shroud with an integrated lube jet is provided for use in, for example, a gearbox of a vehicle such as an aircraft. In some cases, the shroud can include multiple integrated lube jets. In any case, the shroud with the integrated lube jet(s) is provided as a single component that is attached to a housing and can be positioned at or very near to gears. The single component can be built or assembled by various processes including, but not limited to, additive manufacturing, casting and/or brazing.

With reference to <FIG>, a gearbox <NUM> is provided and includes a housing <NUM> that is formed to define an interior <NUM>, meshing gears <NUM> and a shroud <NUM>. The meshing gears <NUM> can include at least a first meshing gear <NUM> and a second meshing gear <NUM> that mesh with one another at a meshing location <NUM>. The first and second meshing gears <NUM> and <NUM> are each rotatable about respective rotational axes defined along rotation shafts <NUM><NUM>, <NUM><NUM> and the first and second meshing gears <NUM> and <NUM> are supported by respective bearings (not shown). At least the meshing location <NUM> and at least one of the rotation shafts <NUM><NUM>, <NUM><NUM> and the bearings <NUM><NUM>, <NUM><NUM> require lubricant. The shroud <NUM> protects lubrication flow in gearbox sump areas and reduces power loss by managing windage. The shroud <NUM> includes integrated lube jets by which lubricant is supplied to satisfy requirements of the meshing location <NUM> and the at least one of the rotation shafts <NUM><NUM>, <NUM><NUM> and the bearings <NUM><NUM>, <NUM><NUM>.

The shroud <NUM> can be disposed within the interior <NUM> at a location proximate to the first and second meshing gears <NUM> and <NUM>. The shroud <NUM> includes a first curved section <NUM> and a second curved section <NUM>. The shroud <NUM> further includes at least one of a first lube jet section <NUM> and a second lube jet section <NUM>. The following description will relate to the cases in which the first curved section <NUM> corresponds to the first meshing gear <NUM>, the second curved section <NUM> corresponds to the second meshing gear <NUM> and the shroud includes both the first lube jet section <NUM> and the second lube jet section <NUM>. This is being done for purposes of clarity and brevity and should not be interpreted as limited the overall scope of the application in any way.

In accordance with embodiments, the first curved section <NUM> can generally wrap around the first meshing gear <NUM> and has a curvature that generally mimics the curvature of an outer surface of the first meshing gear <NUM>. The first curved section <NUM> includes a body <NUM> with an interior facing surface <NUM> that faces the first meshing gear <NUM> at a relatively small distance and an outwardly facing surface <NUM> that faces the housing <NUM>. The outwardly facing surface <NUM> can be mounted to the housing <NUM> by way of a first mounting <NUM>.

In accordance with similar embodiments, the second curved section <NUM> can generally wrap around the second meshing gear <NUM> and has a curvature that generally mimics the curvature of an outer surface of the second meshing gear <NUM>. The second curved section <NUM> includes a body <NUM> with an interior facing surface <NUM> that faces the second meshing gear <NUM> at a relatively small distance and an outwardly facing surface <NUM> that faces the housing <NUM>. The outwardly facing surface <NUM> can be mounted to the housing <NUM> by way of a second mounting <NUM>.

At least one of the body <NUM> of the first curved section <NUM> and the body <NUM> of the second curved section <NUM> is formed to define a main interior channel <NUM>.

The following description will relate to the cases in which the first lube jet section <NUM> is integrated into or with the first and second curved sections <NUM> and <NUM>, in which the second lube j et section <NUM> is integrated into or with the first curved section <NUM> and in which the body <NUM> of the first curved section <NUM> is formed to define the main interior channel <NUM>. This is being done for purposes of clarity and brevity and should not be interpreted as limited the overall scope of the application in any way.

The first lube jet section <NUM> includes a summit <NUM> that is proximate to the meshing location <NUM>. The summit <NUM> is formed by proximal portions of the first and second curved sections <NUM> and <NUM> meeting or coming together in an integral manner so that the bodies <NUM> and <NUM> of the first and second curved sections <NUM> and <NUM> and the summit <NUM> combine to form a unitary or monolithic component. The first lube jet section <NUM> is formed to define a first jetting interior channel <NUM> and an inwardly facing aperture <NUM> at an end or innermost part of the summit <NUM>. The first jetting interior channel <NUM> is fluidly communicative with the main interior channel <NUM> and terminates at the inwardly facing aperture <NUM> at the end or innermost part of the summit <NUM>.

The second lube jet section <NUM> includes an elongate member <NUM> that extends integrally from the interior facing surface <NUM> toward the bearing <NUM><NUM> so that the body <NUM> of the first curved section <NUM> and the elongate member <NUM> combine to form a unitary or monolithic component. The second lube jet section <NUM> is formed to define a second jetting interior channel <NUM> and a laterally facing aperture <NUM> at or near a distal end of the elongate member <NUM>. The second jetting interior channel <NUM> is fluidly communicative with the main interior channel <NUM> and terminates at the laterally facing aperture <NUM> at or near the distal end of the elongate member <NUM>.

With the configurations described above, when the main interior channel <NUM> is chargeable with the lubricant, the lubricant can be communicated into and through the first and second jetting interior channels <NUM> and <NUM> at sufficient pressure to form a longitudinal lubricant jet that impinges on and thus lubricates the meshing location <NUM> upon exiting the inwardly facing aperture <NUM> and to form a sidelong lubricant jet that impinges on and thus lubricates the bearing <NUM><NUM> upon exiting the laterally facing aperture <NUM>.

In accordance with embodiments, plugs <NUM> can be provided to plug open ends of the main interior channel <NUM> and the first and second jetting interior channels <NUM> and <NUM>.

With reference to <FIG>, a shroud forming method <NUM> is provided. The shroud forming method <NUM> includes selecting a gearbox design in which a shroud is to be installed, the gearbox design including a gears, bearings and rotation shafts of the gears and a housing in which the gears, bearings and rotation shafts are disposed (block <NUM>), identifying space between the housing and the gears, bearings and rotation shafts (block <NUM>), identifying locations of the gears, bearings and rotation shafts at which lubrication is warranted (block <NUM>), designing the shroud for installation within the space such that the shroud includes a body and lube jet sections for supplying lubricant to the locations integrated with the body (block <NUM>) and assembling the shroud such that the body and the lube jet sections define interior channels for the lubricant (block <NUM>). The assembling of block <NUM> can include additive manufacturing (in which the forming of the interior channels occurs simultaneously with the building of the shroud) or by some combination of casting and brazing or other similar processes (with the interior channels subsequently formed by drilling and plugging of open ends). The shroud forming method <NUM> can also include mounting the shroud to the housing (block <NUM>) and charging the interior channels with the lubricant (block <NUM>).

Technical effects and benefits of the present disclosure provide for the formation of the shroud of a gearbox with the integrated lube jet(s) in a single component. This allows for an optimized shroud shape and reduced costs and assembly times along with reduced housing core counts, piece part counts, o-ring counts and fastener counts.

Claim 1:
A shroud (<NUM>), comprising:
first (<NUM>) and second (<NUM>) curved sections, at least one of which defines a main interior channel (<NUM>); and
at least one of first (<NUM>) and second (<NUM>) lube jet sections integrated with the first and second curved sections,
characterised by the first lube jet section comprising a summit (<NUM>) at which proximal portions of the first and second curved sections meet and defining an inwardly facing aperture (<NUM>) at the summit and a first jetting interior channel (<NUM>) fluidly communicative with the main interior channel and terminating at the inwardly facing aperture at the summit, and
the second lube jet section comprising an elongate member (<NUM>) extending from one of the first and second curved sections and having a distal end, the elongate member defining a laterally facing aperture (<NUM>) at the distal end and defining a second jetting interior (<NUM>) channel fluidly communicative with the main interior channel and terminating at the laterally facing aperture at the distal end of the elongate member.