Swing drive with oil management system and work vehicle with same

A swing drive for rotating a component of a work vehicle. The swing drive has an electric machine rotating an output shaft about a drive axis and having a planetary set disposed beneath the electric machine. The planetary set has a carrier with pinion shafts having oil passageways therethrough. A splash plate is disposed axially between the electric machine and the planetary set to direct lubricating oil from a face of the electric machine to the oil passageways of the pinion shafts and to direct lubricating oil from the face of the electric machine around the oil passageways. A drive gear is driven to rotate about the drive axis by the electric motor via the double planetary set.

CROSS-REFERENCE TO RELATED APPLICATION(S)

Not applicable.

STATEMENT OF FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not applicable.

FIELD OF THE DISCLOSURE

This disclosure generally relates to work vehicles, and more specifically to swing drives for full-circle rotation of work vehicle components (e.g., work implements and operator cabins).

BACKGROUND OF THE DISCLOSURE

Work vehicles, such as those used for various building, construction, quarrying, roadbuilding, site preparation, and tree harvesting operations, may have features or components that rotate continuously in full circles (i.e., 360 degrees and greater). An excavator, for example, may have an undercarriage on ground engaging tracks that mounts a swing drive to rotate a main frame supporting an operator cab and boom relative to the undercarriage. In other work vehicles, swing drives may be employed to rotate grapples or other work implements.

SUMMARY OF THE DISCLOSURE

The disclosure provides a work vehicle and further provides a swing drive for a rotating a component of a work vehicle. The swing drive has an electric machine and an oil management system.

The swing drive includes an electric machine rotating an output shaft about a drive axis, a planetary set disposed beneath the electric machine coaxial with the drive axis and having a carrier with pinion shafts having oil passageways therethrough, a splash plate disposed axially between the electric machine and the planetary set, and a drive gear driven about the drive axis by the electric machine via the planetary set. The splash plate is configured to direct lubricating oil from a face of the electric machine to the oil passageways of the pinion shafts in order to lubricate an area of the planetary set and to direct lubricating oil from the face of the electric machine away from the oil passageways to lubricate another area the planetary set; and

In some embodiments, each oil passageway includes a first passageway which extends from a top of the associated pinion shaft to a bottom of the associated pinion shaft, and a second passageway extending from the first passageway to a side of the associated pinion shaft. In some embodiments, each first passageway defines a catch cup and a lower passageway, the catch cup having an enlarged diameter relative to the lower passageway.

In some embodiments, a second planetary set disposed beneath the first carrier of the first planetary set. The second planetary set is coaxial with the drive axis and has a second carrier with second pinion shafts having second oil passageways therethrough, and a second splash plate disposed axially below the first carrier. The second splash plate is configured to direct lubricating oil to the second oil passageways and to direct lubricating oil around the second oil passageways. The the drive gear is further driven about the drive axis via the second planetary set. In some embodiments, each oil passageway includes a first passageway which extends from a top of the associated pinion shaft to a bottom of the associated pinion shaft, and a second passageway extending from the first passageway to a side of the associated pinion shaft. In some embodiments, each first passageway defines a catch cup and a lower passageway, the catch cup having an enlarged diameter relative to the lower passageway. In some embodiments, each oil passageway of the first carrier includes a first passageway which extends from a top of the associated pinion shaft to a bottom of the associated pinion shaft, and a second passageway extending from the first passageway to a side of the associated pinion shaft, and each oil passageway of the second carrier includes a first passageway which extends from a top of the associated pinion shaft to a second passageway which extends to a side of the associated pinion shaft. Each first passageway of the first carrier may define a catch cup and a lower passageway, the catch cup having an enlarged diameter relative to the lower passageway.

Power is transmitted from the output shaft of the electric machine to the drive gear via input to a first sun gear of the first planetary set, output from the first carrier to a second sun gear of the second planetary set, and output from a second carrier of the second planetary set to the drive gear.

A drive housing is provided in which the planetary set is disposed. The drive housing including an end plate through which the drive gear extends. A first bearing is provided on the end plate and supports the carrier for rotation relative to the end plate of the drive housing, and the first bearing receives lubricating oil from the planetary set. A second bearing is disposed to an exterior side of the end plate opposite the first bearing. The second bearing receives lubricating oil from the first bearing.

The splash plate may be dome shaped with an arcuate cross-section along all radial lines thereof.

The splash plate includes at least one aperture therethrough which directs lubricating oil from the face of the electric machine around the oil passageways.

A separator may be disposed within an annular splined shaft meshing with a sun gear of the planetary set and including a splash surface configured to direct a portion of lubricating oil passing around the output shaft of the electric machine to the planetary set and a metering passageway directing a portion of the lubricating oil passing around the output shaft to the drive gear.

DETAILED DESCRIPTION

The following describes one or more example embodiments of the disclosed hitch assembly, as shown in the accompanying figures of the drawings described briefly above. Various modifications to the example embodiments may be contemplated by one of skill in the art.

Furthermore, in detailing the disclosure, terms of direction and orientation, such as “forward,” “front,” “aft,” “rear,” “lateral,” “horizontal,” and “vertical” may be used. Such terms are defined, at least in part, with respect to the direction in which the work vehicle travels during use. For example, the terms “forward” and “front” (including “fore” and any further derivatives or variations) refer to a direction corresponding to the primary direction of travel, while the term “aft” and “rear” (and derivatives and variations) refer to an opposing direction. The term “longitudinal axis” may also reference an axis extending in fore and aft directions. By comparison, the term “lateral axis” may refer to an axis that is perpendicular to the longitudinal axis and extends in a horizontal plane; that is, a plane containing both the longitudinal and lateral axes. The term “vertical,” as appearing herein, refers to an axis or a direction orthogonal to the horizontal plane containing the fore-aft and lateral axes.

Generally, a swing drive is used to couple two components of a work vehicle while allowing for 360 degrees or more of rotation. The work vehicle may be an excavator and the swing drive couples an undercarriage of the excavator to a main frame of the excavator. The swing drive is coupled to a post of the undercarriage. The main frame is pivotable about a pivot axis relative to the undercarriage, and may rotate three-hundred sixty degrees via the coupling provided by the swing drive and the post. The main frame supports a work implement which may include a boom assembly having an operable working tool that is used for excavating. The swing drive includes an electric machine, a gear train coupled to the electric machine, a mount attaching a lower end of the electric machine to an upper end of the gear train, a swing mount housing assembly attached to a lower end of the gear train, and a drive gear coupled to the swing mount housing assembly and the gear train. The gear train rotates the drive gear when the gear train is actuated by the electric machine. The gear train includes a plurality of bearings which need lubrication in order to optimally function. In addition, the drive gear has bearings which need lubrication in order to optimally function. The electric machine uses lubricating oil for operation and the lubricating oil is gravity fed into the gear train. The gear train provides improved splash plates and carriers which serve to manage the flow of lubricating oil to optimize the flow of lubricating oil onto the bearings. The splash plates are generally dome shaped and allow for lubricating oil to flow therethrough. The carriers have passageways which route the lubricating oil to the bearings.

The following describes one or more example implementations of the disclosed lubricating oil management systems for an electric swing drive for a work vehicle, as shown in the accompanying figures of the drawings described briefly above.

FIGS.1and2in a particular embodiment as disclosed herein shows a representative self-propelled work vehicle in the form of, for example, a tracked excavator machine10. The work vehicle10includes an undercarriage12including first and second ground engaging units14, commonly referred to as crawler tracks, including first and second travel motors (not shown) for driving the first and second ground engaging units14, respectively. The undercarriage12is generally H-shaped and supports the first and second ground engaging units14along its edges and includes a post16having an outer ring gear18having a plurality of teeth on its inner circumference and an inner cylindrical mount20centrally mounted in the ring gear18. A swing drive100is connected to the ring gear18and the inner mount20and to a main frame22. The main frame22is pivotable about a pivot axis24relative to the undercarriage12, and may rotate three-hundred sixty degrees. The pivot axis24is substantially vertical when a ground surface26engaged by the ground engaging units14is substantially horizontal. The swing drive100is configured to pivot the main frame22on the post16about the pivot axis24relative to the undercarriage12. The teeth of the ring gear18mesh with the swing drive100and the inner mount20engages with the swing drive100.

The main frame22supports a work implement28. As shown, the work implement28includes a boom assembly30with a boom32, an arm34pivotally connected to the boom32, and a working tool36. The term “implement” may be used herein to describe the boom assembly30(or equivalent thereof) collectively, or individual elements of the boom assembly30or equivalent thereof. The boom32is pivotally attached to the main frame22to pivot about a generally horizontal axis relative to the main frame22and may be actuated by hydraulic actuators. The working tool36in this embodiment is an excavator shovel (or bucket) which is pivotally connected to the arm34. The boom32extends from the main frame22along a working direction of the boom32.

In the embodiment ofFIG.1, the first and second ground engaging units14are tracked ground engaging units, although various alternative embodiments of a work vehicle10are contemplated wherein the ground engaging units14may be wheeled ground engaging units. Each tracked ground engaging unit14includes an idler38, a drive sprocket40, and a track chain42extending around the idler38and the drive sprocket40. A travel motor of each tracked ground engaging unit14drives its respective drive sprocket40. Each tracked ground engaging unit14is represented as having a forward traveling direction44defined from the drive sprocket40toward the idler38. The forward traveling direction44of the tracked ground engaging units14also defines a forward traveling direction44of the undercarriage12and thus of the work vehicle10. In some applications, including uphill travel, the orientation of the undercarriage12may be reversed such that a traveling direction of the work vehicle10is defined from the idler38toward its respective drive sprocket40, whereas the work implement(s)28is still positioned ahead of the undercarriage12in the traveling direction.

An engine46for powering the work vehicle10is mounted on the main frame22. The engine46may be an internal combustion engine. The engine46may drive a hydraulic pump to provide hydraulic power to the various operating systems of the work vehicle10.

An operator's cab48may be located on the main frame22. The operator's cab and the boom assembly30may both be mounted on the main frame22so that the operator's cab48faces in the working direction44of the boom assembly30. A control station50may be located in the operator's cab48. The various functions of the work vehicle10may be controlled in part by the appropriate handling of various control devices by an operator occupying the cab48.

As shown inFIGS.2-4, the swing drive100includes an electric machine102, a gear train104coupled to a splined output shaft106of the electric machine102, a mount108attaching a lower end of the electric machine102to an upper end of the gear train104, a swing mount housing assembly110attached to a lower end of the gear train104, and a drive gear112coupled to the swing mount housing assembly and the gear train104. The gear train104rotates the drive gear112when the gear train104is actuated by the electric machine102. A drive axis is defined through a center of the drive gear112.

The swing mount housing assembly110includes an end plate114which houses a first upper bearing116and a second lower bearing118. The end plate114has an outer cylindrical wall120which defines a passageway122extending from an upper end thereof to a lower end thereof, and a circular flange124that extends outward from the outer surface of the outer wall120. An internal wall126extending from the inner surface of the outer wall120separates the passageway122into an upper passageway portion which houses the first upper bearing116, a lower passageway portion which houses the second lower bearing118, and a central passageway portion having a diameter which is less than the diameters of the upper and lower passageway portions. While two bearings116,118are provided, a single bearing116may be provided.

The drive gear112has an upper splined portion130, which is generally cylindrical, a lower splined portion132, which is generally cylindrical, separated by a cylindrical portion134. The upper splined portion130and cylindrical portion134have a smaller diameter than the diameter of the lower splined portion132and seat within the passageway122of the swing mount housing108. The lower splined portion132extends downward from a lower end of the swing mount housing108. An outer race136of the upper bearing116is affixed to the inner surface of the wall forming the upper passageway portion of the passageway122. An outer race138of the lower bearing118is affixed to the inner surface of the wall forming the lower passageway portion of the passageway122, and an inner race140of the lower bearing118is affixed to the cylindrical portion134of the drive gear112and may be coupled together by intermeshing splines.

The teeth of the drive gear112are intermeshed with the teeth of the outer ring gear18of the post16. The flange124of the end plate114is engaged against the inner cylindrical mount20of the post16.

As shown inFIG.5, the gear train104includes at least one planetary set142a,142bmounted within a drive housing144which forms a ring gear. The planetary set142a,142bis disposed beneath the electric machine102coaxial with the drive axis. As shown, two planetary sets142a,142bare shown and described, however, a single planetary set may be provided or more than two planetary sets may be provided. Each planetary set142a,142bincludes a carrier146a,146b, a lower splash plate148a,148bon top of the carrier146a,146b, planet gears150a,150bon top of the lower splash plate148a,148b, a sun gear152a,152bon top of the lower splash plate148a,148band positioned within the planet gears150a,150b, and an upper splash plate154a,154bon top of the planet gears150a,150b. Teeth on the outer periphery of the planet gears150aintermesh with the teeth on the outer periphery of the sun gear152aand the teeth on the inner periphery of the drive housing144. The teeth on the outer periphery of the planet gears150bintermesh with the teeth on the outer periphery of the sun gear152band the teeth on the inner periphery of the drive housing144. Each splash plate148a,148b,154a,154bhas an outer diameter which is less than the internal diameter of the drive housing144. While four planet gears are shown in each planetary set142a,142b, only three or more planet gears are required.

As shown inFIGS.6and7, each carrier146a,146bhas a generally circular planar base156having a central opening158, a lower tubular projection160extending from a lower surface of the base156at the center thereof and surrounding the central opening158, and four equidistantly spaced apart upper cylindrical pinion shafts162,164,166,168extending from an upper surface of the base156. Each base156has an outer diameter which is less than the internal diameter of the drive housing144. The lower projection160has a central passageway170which aligns with the central opening158. An open ended through passageway172extends from a top surface of each pinion shaft162,164,166,168to a bottom surface of the base156, and a passageway174extends from approximately the midpoint of the respective through passageway172to an exit176at a side surface of the pinion shaft162,164,166,168. In the embodiment as shown inFIGS.4,6and7, the passageways172extend axially, and the passageways174extend radially, and a central axis of the passageways172fall along an imaginary circle. As further shown in the embodiment ofFIGS.4,6and7, the passageways174of opposed pinion shafts162,166align with each other, and the passageways174of opposed pinion shafts164,168align with each other.

In the embodiment as shown inFIG.7, each through passageway172has an enlarged upper catch cup and a lower axially extending portion. As shown, the upper catch cup includes an upper passageway portion178which extends from the upper end of each pinion shaft162,164,166,168, to a vertical intermediate elongated cylindrical passageway portion180which has a diameter which is less than the diameter of the upper passageway portion178at its upper end, and to a generally tapered passageway portion182. In other embodiments, each upper catch cup is generally tulip shaped or is formed by a continuously tapering wall such that a cone is formed. In the embodiment as shown inFIG.7, the axially extending portion is a vertical lower elongated cylindrical passageway portion184which has a diameter which is less than the diameter of the intermediate passageway portion180. The passageway174extends from a lower end of the respective intermediate passageway portion180. The passageway portions180,184may be cylindrical.

As shown inFIGS.8and9, each splash plate148a,148b,154a,154bis formed of a circular plate186having a central opening188, equidistantly spaced apart openings190extending from an upper surface thereof to a lower surface thereof surrounding the central opening188, and at least one aperture192extending from an upper surface thereof to a lower surface thereof surrounding the central opening188. As shown, four equidistantly spaced apertures192are provided. As shown, the openings190and the apertures192alternate with each other around the circumference of the plate186. The plate186is generally dome-shaped. The plate186preferably has an arcuate cross-section as shown inFIG.9along all radial lines thereof. In an embodiment, the plate186is planar. An indentation194may surround each opening190.

As shown inFIG.10, each planet gear150a,150bhas a tubular inner race196and a tubular outer race198coupled together by a plurality of upper roller bearings200and a plurality of lower roller bearings202which are separated from each other by a washer204. The inner race196defines a central cylindrical passageway206from an upper end thereof to a lower end thereof. A plurality of spaced apart passageways208are provided in the inner race196and extend from the central passageway206to the washer204. The outer race198has a plurality of teeth on its outer surface.

The pinion shafts162,164,166,168of the carrier146a,146bextend through the openings190of the lower splash plate148a,148b. The respective planet gears150a,150bsurround the respective pinion shafts162,164,166,168of the carrier146a,146band sit on the thrust splash plate148a,148b. The exit176of the passageway174of the respective pinion shafts162,164,166,168vertically align with the through passageways208of the respective planet gear150a,150b. The pinion shafts162,164,166,168further extend through the openings190of the upper splash plate154a,154band extend outwardly from the upper splash plate154a,154b.

Each sun gear152a,152bhas a wall210having a central passageway212extending from an upper end thereof to a lower end thereof. A portion214of the wall forming the central passageway212is splined. An upper portion216of the outer surface of the wall210has an outer cylindrical surface which has splines therein, and a lower portion218of the outer surface of the wall210has a plurality of teeth220. The teeth220define an outer diameter which is greater than the outer diameter of the upper portion216.

The sun gear152aextends through the central opening158of the carrier146aand the central opening188of the lower splash plate148a, and extends between the planet gears150aand the teeth220intermesh with the teeth of the planet gears150a, and extends through the central opening188of the upper splash plate154a. The sun gear152aextends upwardly from the upper splash plate154a. The teeth of the planet gears150aintermesh with each other, intermesh with the teeth220of the sun gear152a, and intermesh with the teeth of the drive housing144. The sun gear152bseats within the central opening158of the carrier146band the central opening188of the lower splash plate148b, extends between the planet gears150band the teeth220intermesh with the teeth of the planet gears150b, extends through the central opening158of the upper splash plate154b, and through the central opening158of the upper carrier146a. The sun gear152bextends upwardly from the upper splash plate154b. The teeth of the planet gears150bintermesh with each other, intermesh with the teeth220of the sun gear152b, and intermesh with the teeth of the drive housing144.

The lower projection160of the carrier146ahas splines thereon which interengage with the splines on the upper portion216of the sun gear152band sits above the teeth220of the sun gear152b. The base156of the carrier146ais spaced from the upper ends of the pinion shafts162,164,166,168of the carrier146b.

The lower projection160of the carrier146bextends into the upper passageway portion of the passageway122of the swing mount housing assembly110and is positioned between the upper splined portion130of the drive gear112and an inner race222of the upper bearing116. The central passageway170of the lower projection160of the carrier146bis splined and intermeshes with splines on the upper splined portion130of the drive gear112. The inner race222of the upper bearing116is affixed to the outer surface of the lower projection160and may be coupled together by intermeshing splines.

A washer having a central opening is provided between the sun gears152a,152b. The washer is secured through grooves in the mating sun gears152a,152band held in place with gravity.

A separator224is mounted within the portion214of the central passageway212of the sun gear152band has splines on an outer surface thereof which engage with the splines of the portion214. The separator224has a central passageway226extending from an upper end thereof to a lower end thereof. An O-ring is provided between the separator224and the sun gear152b.

In operation, when the output shaft106rotates, the splined coupling of the output shaft106and the sun gear152acauses the sun gear152ato co-rotate. The intermeshed teeth of the sun gear152aand the planet gears150acauses the planet gears150ato rotate. The intermeshed teeth of the planet gears150aand the drive housing144causes the carrier146aand splash plates148a,154ato rotate relative to the drive housing144. The splined coupling of the carrier146aand the sun gear152bcauses the152bto rotate. The intermeshed teeth of the sun gear152band the planet gears150bcauses the planet gears150bto rotate. The intermeshed teeth of the planet gears150band the drive housing144causes the carrier146band splash plates148b,154bto rotate relative to the drive housing144. The splined coupling of the carrier146band the drive gear112causes the drive gear112to rotate. The intermeshed teeth of the drive gear112and the outer ring gear18and the engagement of the circular flange124of the end plate114causes the swing drive100and the main frame22to rotate relative to the undercarriage12.

The planetary sets142a,142band drive housing144effect a gear ratio change to rotate the main frame22relative to the undercarriage12around the pivot axis24. Other configurations of the planetary sets142a,142bmay be incorporated without departing from the scope of the present disclosure. While two planetary sets142a,142bare shown and described, a single planetary set can be provided, or more than two planetary sets can be provided.

Oil flows from a face of the electric machine102under gravity into the gear train104and passes through the gear train104through a variety of flow paths to lubricate the bearings of the planet gears150a,150band the bearing116.

The lubricating oil flows under gravity fall from the face of the electric machine102and into the open enlarged upper passageway portions178of the carrier146a, and through the intermediate passageway portions180and into the passageway portions182. The shape of the passageways172promotes the entry of the oil into the passageways172. The size of the passageways172meters the flow of lubricating oil therethrough. Some lubricating oil that is not captured within the passageways172spills onto the splash plate154aand collects in the indentation194, and then flows across the splash plate154aand passes through the aperture(s)192. The dome shape of the splash plate154aassists in directing the flow of the lubricating oil. The lubricating oil flows through the aperture(s)192of the splash plate154aand onto the teeth of the planet gears150bto lubricate and then further flows as described below. Because of the rotation of the carrier146a, centrifugal force causes fluid flow off of the splash plate154a, around the carrier146aand onto the teeth of the planet gears150band the drive housing144to lubricate and then further flows as described below.

Because of the rotation of the carrier146a, centrifugal force causes fluid flow through the passageways174. The planet gears150aare rotating relative to the pinion shafts162,164,166,168. When the passageways208in the planet gears150aalign with the passageways174of the pinion shafts162,164,166,168, lubricating oil flows through the inner races196to the bearings200,202to lubricate the bearings200,202. The lubricating oil then flows down through the lower ends of the planet gears150aand onto the splash plate148a. The lubricating oil then flows through the aperture(s)192of the splash plate148a, through the aperture(s)192of the splash plate154b, onto the teeth of the planet gears150bwhich lubricates the intermeshing teeth of the planet gears150b, through the aperture(s)192of the splash plate148b, and around the carrier146b. Some lubricating oil flows around the splash plates148a,154b,148band carriers146a,146b. Oil then flows through a port228in the end plate114that is in communication with an opening230in the outer race of the bearing116to allow lubricating oil to flow into and lubricate the bearing116. The lubricating oil flows down out of the bottom of the bearing116to an exit port232of the end plate114. The lubricating oil is then cooled and returned to the electric machine102for reuse.

Lubrication oil also flows through from the passageway portions182into the lower passageway portions184under gravity, and then into the open enlarged upper passageway portions178of the carrier146b, through the intermediate passageway portions180of the carrier146b, through the passageway portions182of the carrier146b. The lubricating oil then flows through the aperture(s)192of the splash plate154band onto the teeth of the planet gears150band then further flows as described below. Like that of carrier146a, any lubricating oil that is not captured within the passageways172spills onto the splash plate154band then ultimately flows to the exit port232.

Because of the rotation of the carrier146b, centrifugal force causes fluid flow through the passageways174. The planet gears150bare rotating relative to the pinion shafts162,164,166,168of the carrier146b. When the passageways208in the planet gears150balign with the passageways174of the pinion shafts162,164,166,168of the carrier146b, lubricating oil flows through the inner races196to the bearings200,202to lubricate the bearings200,202. The lubricating oil then flows down through the lower ends of the planet gears150band onto the splash plate148b. The oil then flows through the aperture(s)192of the splash plate148band around the splash plate148b, and around the carrier146bto the exit port232. Some lubricating oil flows around the splash plates148aand carriers146bto the exit port232.

Oil also flows through from the passageway portions182of the carrier146binto the lower passageway portions184of the carrier146b, and out the lower end of the base156of the carrier146bto the exit port232.

Oil is also received from a passageway234through the output shaft106. Oil flows from the passageway234into the passageway212of the sun gear152a, into the passageway226of the separator224, and then into the passageway212of the sun gear152b. The oil seeps through the interface between the upper splined portion130of the drive gear112and the lower tubular projection160of the carrier146b, which then flows to the exit port232.

The lubricating oil also drips down between the components of the swing drive100until captured at the exit port232.

The bearing118may be supplied with a separate port236which is in communication with an opening in the outer race of the bearing118to allow lubricating oil to flow into and lubricate the bearing118.

In an embodiment as shown inFIG.17, the lower passageway portions184of the carrier146bare eliminated and all of the lubricating oil flowing through the passageways172flows through the passageways174.

In an embodiment as shown inFIG.18, the passageway172shown in carrier146ais a through passageway172extending from the top of the pinion shaft162,164,166,168to the bottom thereof. The passageway172has an inverted enlarged upper catch cup and a lower axially extending portion. As shown, the upper catch cup includes an axially extending upper passageway portion238which extends from the upper end of each pinion shaft162,164,166,168, to a generally tapered passageway portion240, and to an axially extending lower passageway portion242which extends from the lower end of each pinion shaft162,164,166,168. The upper passageway portion238has a diameter which is less the diameter of the lower passageway portion242. In another embodiment, each upper catch cup is formed by a continuously tapering wall such that a cone is formed. An insert244is provided in the lower passageway portion242to form the lower axially extending portion246. The passageway portions238,240,246may be cylindrical. This same passageway172can be provided in the lower carrier146bwith the outlet of the lower passageway portion242of carrier146baligning with the upper passageway portion238of carrier146a.

As also shown in the embodiment ofFIG.18, the passageway172is not a through passageway172which extends from the top of the pinion shaft162,164,166,168to the bottom thereof, and instead extends from the top of the pinion shaft162,164,166,168and at an angle relative to the axial axis of the pinion shaft162,164,166,168to the passageway174. The passageway174also extends at that same angle from the exit of the passageway172to the exit176at the side surface of the pinion shaft162,164,166,168. The passageway172is formed as a catch cup as described herein. The passageway172may be cylindrical.