Air vent system for constant velocity joints

An air venting system for a constant velocity joint (20) having an inner race (24), an outer race (22), a cage (26), a plurality of torque transferring elements (28), a drive sleeve, a drive nut and a boot assembly. The outer race has a wall portion (90) having a vent hole (88, 242) with a first and a second axially extending channel (224, 264). A radially extending wall integrally connects the second axially extending channel to the first axially extending channel. A valve (256) having a stopper portion (264), a disk portion (258) and a breather portion (260) is at least partially located within the vent hole. The breather portion (260) further includes an axially extending ring (292) that terminates in a radially extending wall. At least a portion (300) of an edge portion of the radially extending wall of the breather portion of the valve is in direct contact with at least a portion (250) of an outer surface of the wall portion of the outer race.

FIELD OF THE DISCLOSURE

The present disclosure relates to a constant velocity joint for use in a vehicle having an air vent system with a valve.

BACKGROUND OF THE DISCLOSURE

Vehicles having a drive train with one or more drive shafts or propeller shafts that operate at a variable angle typically employ the use of one or more constant velocity joint assemblies. The constant velocity joint assembly allows the one or more drive shafts or propeller shafts in the drive train to transmit the rotational energy generated by an engine of the vehicle through a variable angle at a constant rotational speed and without an appreciable increase in friction or play. Typical constant velocity joints include the use of a rubber boot assembly to seal the components of the constant velocity joint from exposure to the environment. Additionally, conventional constant velocity joints typically include the use of a grease or a lubricant to reduce the amount of wear and to reduce the amount of friction in the constant velocity joint system. Finally, conventional constant velocity joint assemblies further include the use of a flexible boot assembly that seals the components of the constant velocity joint assembly from the environment. The flexible boot assembly additionally aids in retaining the grease or lubricant within the constant velocity joint assembly.

As the constant velocity joint articulates and rotates in operation, the pressure within the constant velocity joint assembly increases. It is also well understood that the pressure within the constant velocity joint assembly will increase and decrease based on the conditions of the external environment the constant velocity joint assembly is in. As the pressure within the constant velocity joint assembly increases and decreases it exerts a force onto the boot of the constant velocity joint assembly thereby constantly changing the shape and geometry of the boot. Additionally, as the pressure within the constant velocity joint changes it causes what is referred to as boot-to-boot contact. Boot-to-boot contact is when portions of the boot that typically do not come into contact with one and another do come into contact with one and another. Finally, as the pressure within the constant velocity joint changes it causes what is referred to as a boot inversion. A boot inversion is when the portions of the boot that should not be axially blown outward are axially blown outward. All of this results in an undesirable reduction of the life and the durability of the constant velocity boot. It would therefore be advantageous to develop a way to vent the pressure within the constant velocity joint assembly and increase the life and durability of the boot of the constant velocity assembly.

In order to alleviate the pressure within the constant velocity joint assembly, conventional constant velocity joint assemblies also include the use of a vent hole. The vent hole allows the constant velocity joint to vent off the excess pressure within the assembly thereby reducing the amount of force exerted on the boot. A common problem with these systems is that the constant velocity joint assembly may leak some of the grease or the lubrication fluid contained within the constant velocity joint assembly through the vent hole. Leakage of the grease or lubrication fluid typically occurs when the constant velocity joint assembly is in a static position not in operation and the assembly is articulated to an angle θ such that the vent hole falls below the grease or lubrication fluid fill line. Once the vent hole falls below the grease or lubrication fluid line, the grease or lubrication fluid begins to leak out of the constant velocity joint assembly. This can result in a reduction in the life of the constant velocity joint assembly. It would therefore also be advantageous to develop a constant velocity joint venting system that will vent the excess pressure from within the assembly and will reduce and/or eliminate the leakage of the grease or lubrication fluid from the assembly when the assembly is in a static position.

To solve the problem of grease or lubricant fluid leakage out of the constant velocity joint assembly, many conventional constant velocity joint assemblies typically employ the use of a valve. The valve is typically made of a flexible material and is press-fitted into the vent hole of the constant velocity joint assembly. Once the pressure within the constant velocity joint assembly reaches a pre-determined pressure, a lip portion of the valve flexes allowing the excess pressure from within the assembly to be vented to the atmosphere. The venting of these conventional valve systems is solely dependent on the internal pressure of the constant velocity joint assembly whether or not the assembly is in a static or a dynamic condition. The problem with conventional valve systems is that if the design of the valve is such that the valve will not flex until the internal pressure of the assembly is at a relatively high pressure, it will still exert an undesirable amount of force onto the boot and/or it will cause undesirable boot-to-boot contact and/or boot inversion which will result in a reduction of the life and durability of the boot. In contrast, if the valve is designed to flex at too low of a pressure, the valve will open too easily which can result in unwanted grease or lubrication fluid leakage from the constant velocity joint assembly. It would therefore be advantageous to develop a constant velocity joint venting system that will be allow the valve to open at a lower pressure when in a dynamic condition versus when in a static condition.

SUMMARY OF THE DISCLOSURE

An air venting system for a constant velocity join having an inner race, an outer race, a plurality of torque transferring elements, a drive sleeve, a drive nut and a boot assembly. The outer race of the constant velocity joint has a wall portion. The wall portion of the outer race of the constant velocity joint has a vent hole having a first axially extending channel and a second axially extending channel. A radially extending wall integrally connects the second axially extending channel to the first axially extending channel on the wall portion of the outer race. The first axially extending channel has a diameter D1that is larger than the diameter D2of the second axially extending channel on the wall portion of the outer race.

A valve having a stopper portion, a disk portion and a breather portion is at least partially located within the vent hole in the wall portion of the outer race of the constant velocity joint. The stopper portion of the valve includes a first axial inner portion, a second axial outer portion and a radially outward extending portion that is disposed between the first axial inner portion and the second axial outer portion of the valve. The first axial inner portion is at least partially located within the first axially extending channel in the wall portion of the outer race of the constant velocity joint. Additionally, the second axial outer portion of the stopper portion of the valve is located within the second axially extending channel in the wall portion of the outer race.

Disposed axially adjacent to the second axial outer portion of the stopper portion of the valve is the disk portion having an inner surface and an outer surface. The disk portion of the valve extends radially outward from the second axial outer portion of the stopper portion of the valve.

The breather portion of the valve has an axially extending ring that terminates in radially extending wall. At least a portion of an edge portion of the radially extending wall of the breather portion of the valve is in direct contact with at least a portion of an outer surface of the wall portion of the outer race.

DETAILED DESCRIPTION OF THE DISCLOSURE

A constant velocity joint assembly20will be described herein. The constant velocity joint assembly20will be described in connection with a vehicle (not depicted). However, it would be understood by one of ordinary skill in the art that the present disclosure could have industrial, locomotive, and aerospace applications.

The constant velocity joint assembly20may have applications to on-highway and off-highway vehicles. Further, the assembly20can be utilized with an all-wheel drive vehicle. Also, it should be appreciated that the assembly20could be utilized with a rear wheel drive vehicle or a front wheel drive vehicle.

Referring now to the drawings, there is illustrated inFIG. 1an embodiment of a constant velocity joint assembly20in accordance with the present disclosure. The constant velocity joint assembly20includes an outer race22, an inner race24, a cage26, a plurality of torque transferring elements28, a drive sleeve30, a drive nut32, and a boot assembly34. A plug-in pinion shaft36is drivingly engaged with the drive sleeve30, and the drive sleeve30is drivingly engaged with the inner race24. Preferably, the outer race22, inner race24, drive sleeve30, drive nut32, boot assembly34and plug-in pinion shaft36are aligned with a longitudinal axis38of the assembly20. The constant velocity joint assembly20may be of the Rzeppa variety. However, it should be understood that the constant velocity joint assembly may be any other type or variety of constant velocity joint.

The outer race22is a hollow cylindrical body formed from a rigid material, such as but not limited to iron, steel, aluminium or an alloy thereof. Typically, the outer race22is forged and then machined in a secondary operation. However, it is understood the outer race22may be formed using other processes from any rigid material. An attachment end40is formed in the outer race22, and is drivingly engaged with a shaft (not shown). Alternately, it is understood that the attachment end40may be coupled to any other type of member.

A plurality of outer tracks42are formed in an inner surface44of the outer race22. Each of the outer tracks42has an arcuate profile which follows an arcuate path, the arcuate path having a center point different from a center point of the constant velocity joint assembly20. Preferably, the outer race22includes eight outer tracks42formed therein. However, it is understood that each of the outer tracks42may have a non-arcuate profile and any number of the outer tracks42may be formed in the outer race22. The plurality of outer tracks42are equally spaced about the axis of the outer race22.

The inner surface44of the outer race22is a spherical surface having a center point different from the center point of the constant velocity joint assembly20. A radius of the inner surface44is complementary to an outer surface46of the cage26. Typically, the plurality of outer tracks42and the inner surface44are precision machined for use as surfaces of a constant velocity joint assembly as is known in the art.

The inner race24is a hollow member formed from a rigid material such as but to limited to iron, steel, aluminium or an alloy thereof. It is understood that the inner race24may be formed using any conventional process from any rigid material. When the drive sleeve30is drivingly engaged with the inner race24, the inner race24is typically spliningly disposed on an end portion of the drive sleeve30.

The inner race24includes an inner race outer surface27and an inner race inner surface29. The inner race outer surface27of the inner race24is a spherical surface having a center point common with the center point of the constant velocity joint assembly20. The inner race inner surface29of the inner race24defines a substantially cylindrical bore through the inner race24. A plurality of splines52are formed on the inner race inner surface29for drivingly engaging the inner race24with the drive sleeve30.

A plurality of inner tracks54are formed in the inner race outer surface27. Each of the inner tracks54has an arcuate profile which follows an arcuate path. The arcuate path of the inner tracks54have a center point that is different from a center point of the constant velocity joint assembly20. Additionally, the diameter of the arcuate profile of each of the inner tracks54is complementary to the diameter of the arcuate profile of each of the outer tracks42corresponding thereto. As shown inFIG. 1, a depth of each of the inner tracks54varies depending on a distance the inner race outer surface27is from the axis of the inner race24. Preferably, the inner race24includes eight inner tracks54formed therein. However, it is understood that each of the inner tracks54may have a non-arcuate profile and any number of the inner tracks54may be formed in the inner race24. The plurality of inner tracks54are equally spaced about the axis of the inner race24.

A snap ring56is used to secure the inner race24to the drive sleeve30. The snap ring56is disposed in a groove58that is formed in an outer surface of the drive sleeve30. Alternately, any other type of fastener may be used to secure the inner race24to the drive sleeve30.

The cage26is a hollow body that is disposed between the outer race22and the inner race24. In a non-limiting example, the cage26is machined from a rigid material such as iron, steel, aluminium or an alloy thereof. However, it is understood that the cage26may be formed using other processes and from any rigid material. Additionally, the cage26further includes a spherical outer surface60and a spherical inner surface62. A plurality of perforations64is formed through the cage26.

The spherical outer surface60has a center point common with the center point of the constant velocity joint assembly20. The spherical outer surface60defines a portion of each of the perforations64. Disposed against and slidingly engaged with the inner surface44of the outer surface22is the spherical outer surface60of the cage26. A diameter of the spherical outer surface60is complementary to the inner surface44of the outer race22. It is understood that the spherical outer surface60and the inner surface44may be precision machined for use as mating surfaces of a constant velocity joint as is known in the art.

The spherical inner surface62has a center point common with the center point of the constant velocity joint assembly20. Additionally, the spherical inner surface62defines a portion of each of the perforations64. Disposed against and slidingly engaged the inner race outer surface27is the spherical inner surface62of the cage26. A radius of the spherical inner surface62is complementary to a radius of the inner race outer surface27. It is understood that the spherical inner surface62and the inner race outer-surface60may be precision machined for use as mating surfaces of a constant velocity joint as is known in the art.

The plurality of torque transferring elements28comprises a plurality of spheres that are disposed in each of the perforations64, the outer tracks42, and the inner tracks54of the constant velocity joint assembly20. As a non-limiting example, each of the torque transferring elements28is a ball bearing that is made of iron, steel, aluminium or an alloy thereof as is commonly known in the art. However, it is understood that the plurality of torque transferring elements28may be any other shape and formed from any other rigid material. A diameter of each of the torque transferring elements28is complementary to the diameter of the arcuate profiles of each of the outer tracks42and the inner tracks54. The torque transferring elements28, the outer tracks42and the inner tracks54are precision machined for use as mating surfaces of a constant velocity joint assembly as is known in the art. One torque transferring element of the plurality of the torque transferring elements28is disposed in and contacts one of the outer tracks42and one of the inner tracks54. Additionally, the torque transferring element is also in sliding engagement with the outer track42and the inner track54it is disposed in.

Disposed against and in driving engagement with the inner race24is the drive sleeve30. As a non-limiting example, the drive sleeve30is an annular member formed from a rigid material such as iron, steel, aluminium or an alloy thereof. It is understood that the drive sleeve30may be formed using any conventional process from any rigid material. As illustrated inFIGS. 1-3, the drive sleeve30comprises a first end portion66, a middle portion68, and a second end portion70. The first end portion66is drivingly engaged with the inner race24, the middle portion68is disposed against the inner race24, and the second end portion70is drivingly engaged with the plug-in pinion shaft36.

The first end portion66is a generally cylindrically shaped portion of the drive sleeve30that is spliningly engaged with the inner race24. A plurality of splines72are formed in an outer surface of the first end portion66. Alternately, it is understood that the drive sleeve30may be unitarily formed with the inner race24or coupled thereto in any conventional manner. The groove58is formed in the first end portion66of the drive sleeve30.

A stopper portion74is attached to the drive sleeve30. More specifically, the stopper portion74is attached to the first end portion66of the drive sleeve30. As non-limiting example, the stopper portion74is made of iron, an iron alloy, aluminium, an aluminium alloy, steel, a steel alloy, a plastic material, an elastomeric material, a rubber material and/or a carbon fibre material. It is understood that the stopper portion may be formed of other rigid materials.

As illustrated inFIGS. 2-4, the stopper portion74is of a generally annular shape such that an outer portion76and an inner portion78define a cavity84. The cavity84is in fluid communication with a first vent hole88provided through a wall portion90of the outer race22. Additionally, the cavity84is in fluid communication with first vent hole88via a space92that is defined by the wall portion90.

In certain embodiments, the diameter of the cavity84gradually increases in length toward an outer end94of the stopper portion74, as shown inFIG. 1. The cavity84may be of a frusto-conical shape. In according with this embodiment, the diameter of the cavity84gradually increases in length to the outer end94of the stopper portion74. Further, it should be appreciated that the cavity84may be of another conic shape.

The outer portion76of the stopper portion74may be of a generally cylindrical shape and has an outer diameter96which along its length is substantially constant. According to an embodiment of the disclosure, the outer portion76gradually decreases in thickness toward the outer end thereof. Additionally, the outer portion76of the stopper portion74extends into the space92defined by the wall portion90of the outer race22and is positioned adjacent the wall portion90.

A ramped transition108connects the first end portion66of the drive sleeve30with the outer portion76of the stopper portion74. According to an embodiment of the disclosure, the stopper portion74is formed in a unitary manner with the drive sleeve30.

As previously discussed, the wall portion90defines the space92. The space92is in fluid communication with the interior82of the constant velocity joint assembly20and an area126that is partially defined by an inner diameter128of a shaft130via the first vent hole88.

As illustrated inFIGS. 2 and 3, when the constant velocity joint assembly20is at a maximum articulation angle β, the outer portion76of the stopper portion74abuts the wall portion90of the outer race22. When the outer portion76abuts the wall portion90, the constant velocity joint assembly20is limited to the maximum articulation angle β. At the maximum articulation angle β, the outer portion76abuts the inboard extending portion142and the end144thereof. Limiting the constant velocity joint assembly20to the maximum articulation angle β prevents damage to the boot assembly34which may occur when the constant velocity joint assembly20, exceeds the maximum articulation angle β.

Referring back toFIG. 1, the middle portion68is a substantially disk shaped portion of the drive sleeve30that is located between the first end portion66and the second end portion70. The middle portion68of the drive sleeve30has an outer diameter that is greater than an outer diameter of the first end portion66of the drive sleeve30. The middle portion68of the drive sleeve30defines a sleeve seat146of the drive sleeve30. As illustrated inFIGS. 1-3, the sleeve seat146is angled and connected to a radial portion150that extends substantially vertically. When the first end portion66is drivingly engaged with the inner race24, the sleeve seat146is disposed against a portion of the inner race24with a complementary shape.

Opposite the first end portion66of the drive sleeve30is the second end portion70of the drive sleeve30. The second end portion70of the drive sleeve30is hollow and comprises a first inner diameter portion152and a second inner diameter portion154that are connected by a ramped transition156. As illustrated inFIGS. 1-3, the first inner diameter portion152has a smaller diameter than the second inner diameter portion154.

Additionally, the second end portion70of the drive sleeve30further comprises a plurality of inner splines158on the first inner diameter portion152, a boot groove160, a first O-ring groove162and a first snap ring groove164. A first O-ring166is located within the first O-ring groove162and a first snap ring168is located within the first snap ring groove164. The grooves162and164and rings166and168are located on an outer surface170of the second end portion70of the drive sleeve30. As illustrated inFIGS. 1-3, the second end portion70is sealingly engaged with at least a portion of the boot assembly34.

The plurality of inner splines158are formed on the first inner diameter portion152of the second end portion70for drivingly engaging the plug-in pinion shaft36. Alternatively, the second end portion70may be coupled to the plug-in pinion shaft36in any manner that permits sliding engagement.

The first snap ring168engages a snap ring groove172on a first inside surface174of the drive nut32. The first snap ring168axially secures the drive nut32to the drive sleeve30. Alternatively, it is understood that the second end portion70may be configured to be engaged with the drive nut32in any conventional manner. Additionally, the O-ring166tightly seals the interface between the drive nut32and the drive sleeve30.

On the outer surface170of the second end portion70of the drive sleeve30is the boot groove160that is an annular recess circumferentially extending along at least a portion of the outer surface170of the second end portion70of the drive sleeve30. The boot groove160is formed intermediate the grooves162and164and the middle portion68. As illustrated inFIGS. 1-3, the boot groove160receives at least a portion of, and is sealingly engaged with, the boot assembly34. Alternatively, it is understood that the second end portion70may be configured with another feature which receives and sealingly engages the boot assembly34with the drive sleeve30.

The drive nut32is a hollow annular member comprising a first portion176and a second portion178. In a non-limiting example, the drive but32is formed from a rigid material such as iron, steel, aluminium or an alloy thereof. It is understood that the drive nut32may be formed using any conventional process from any rigid material. According to an embodiment of the disclosure, the portions176and178of the drive nut32are unitary and integrally formed. At least a portion of the first portion176of the drive nut32radially overlaps at least a portion of second end portion70of the drive sleeve30. The first portion176has a larger inner diameter portion180than an inner diameter portion182of the second portion178. Additionally, the first portion176of the drive nut32has the snap ring groove172.

A first chamfered surface184on the first portion176of the drive nut32is located proximate the snap ring groove172to facilitate compression of the snap ring168during assembly.

The inner diameter182of the second portion178has a plurality of threads186thereon. The drive nut threads186engage with a complementary set of threads on the shaft36. Additionally, the inner diameter182also defines a second snap ring groove195that is complementary to a snap ring groove196located on the shaft36. A snap ring194is located within grooves195and196to axially secure the nut32and shaft36together. The shaft36also has an O-ring groove190within which an O-ring192is located. It is understood that the O-ring190seals the interface between the shaft36and the nut32.

As illustrated inFIGS. 1-3, the boot assembly34includes a boot retainer198and boot200. At least a portion of the boot assembly34is disposed on the outer race22and is in sealing engagement with the drive sleeve30. A crimped portion of the boot retainer198couples the boot200to the boot retainer198. The boot200is sealingly engaged with the drive sleeve30using a boot band assembly202. According to an embodiment of the disclosure, the boot band assembly202is a clamping device. It should be understood that other types of clamping devices may be used with the constant velocity joint assembly20to sealingly engage the boot200with the drive sleeve30.

The boot retainer198is an annular member formed from a rigid material, such as but not limited to a metal, a plastic, rubber or an elastomeric material. As illustrated inFIGS. 1-3, the boot retainer198is coupled to and is sealingly engaged with the outer race22of the constant velocity joint20. A first end portion204of the boot retainer198engages a shoulder206defined by an outer surface208of the outer race22. However, it should be appreciated that the boot retainer198may be coupled to the outer race22in other manners. A sealing member (not shown) such as, for example, an O-ring may be positioned between the boot retainer198and the shoulder206in a-groove (not shown) formed in the outer surface208of the outer race22to provide a seal between the boot retainer198and the outer race22.

A second end portion214of the boot retainer198has a substantially U-shaped cross-section which encloses a portion of the boot200thereby coupling the boot200to the boot retainer198. Alternately, the second end portion214may have other shapes that facilitate coupling the boot200to the boot retainer198.

The boot200is an annular member having a substantially U-shaped cross-section formed from a resilient material, such as an elastomer. The boot200facilitates movement between the outer race22and the drive sleeve30while maintaining a sealing engagement therebetween. A first end portion216of the boot200is coupled to the boot retainer198as described hereinabove. A second end portion218of the boot200is sealingly engaged with and coupled to the boot groove160of the drive sleeve30as described hereinabove.

Drivingly engaged with the drive sleeve30when the constant velocity joint20is assembled is the plug-in pinion shaft36having a first end portion220, a middle portion222, and a second end portion224. The plug-in pinion shaft36is an elongated member that is formed from a rigid material, such as but not limited to iron, steel, aluminium or an alloy thereof using any conventional process.

The first end portion220of the plug-in pinion shaft36is substantially cylindrical in shape and formed opposite the second end portion224. As illustrated inFIGS. 1-3, the first end portion220of the plug-in pinion shaft36comprises a plurality of outer splines226that are corresponding to the inner splines158of the drive sleeve30. When the constant velocity joint assembly20is assembled, the plug-in pinion shaft36is drivingly engaged with the drive sleeve30through the splines158and226so that the two rotate together as one. The plurality of outer splines226are formed on an outer surface228of the plug-in pinion shaft36. According to an alternative embodiment of the disclosure, it is understood that the plug-in pinion shaft36may be drivingly engaged with the plug-in pinion shaft36in any manner that permits sliding engagement.

The middle portion222is a substantially cylindrically shaped portion of the plug-in pinion shaft36formed between the first end portion220and the second end portion224. As illustrated inFIGS. 1-3, the middle portion222has a larger diameter than the first end portion220of the plug-in pinion shaft36. Additionally, the two portions220and222are separated by a ramped transition portion220. The snap ring and O-ring grooves196and190previously discussed are located in middle portion222of the plug-in pinion shaft36. In order to secure the plug-in pinion shaft36to the drive nut32so that the two rotate together, the middle portion222of the plug-in pinion shaft36also comprises a set of threads232for engaging the threads186on the drive nut32.

Drivingly engaged with a drive component (not shown) is the second end portion224of the plug-in pinion shaft36. According to an embodiment of the disclosure, the second end portion224may have a beveled pinion gear that engages the drive component (not shown). However, it should be appreciated that the second end portion224of the plug-in pinion shaft36may be configured in any manner that permits driving engagement between the plug-in pinion shaft36and the drive component (not shown).

Grease or any other suitable lubricant is disposed within the interior82of the constant velocity joint assembly20to lubricate the torque transfer elements28and thus improve their slidability and increase the useful life of the constant velocity joint assembly20. When the constant velocity joint20is spinning at high speeds, pressure is created in the interior82. This pressure is then vented from the interior82of the constant velocity joint20via the first vent hole88.

The first vent hole88is provided through at least a portion of the outer race22of the constant velocity joint20. According to an embodiment of the disclosure, the first vent hole88is provided through and located in the wall portion90of the outer race22along the longitudinal axis38of the assembly20. The first vent hole88provides fluid communication between the space92that is defined by the wall portion90of the outer race22and the area126that is partially defined by the inner diameter128of the shaft130.FIGS. 1-3of the disclosure depicts a single first vent hole88aligned with the longitudinal axis38of the assembly20. According to yet another embodiment of the disclosure (not shown), the outer race22of the constant velocity joint assembly20includes additional vent holes in the wall portion90.

When the constant velocity joint assembly20is spinning, the outer portion76of the stopper portion74moves within the space92. Movement of the stopper portion74within the space92helps to vent the interior82of the constant velocity joint assembly20by creating air circulation in the space92and through the first vent hole88. Air circulation through the first vent hole88also enhances the venting of the interior82of the constant velocity joint assembly20by helping to prevent blockages in and around the first vent hole88from forming.

Drivingly engaged with the shaft130is the attachment end40of the outer race22. As a non-limiting example, the engagement of the shaft130to the attachment end40of the outer race22is typically done via welding, but other attachment methods may also be used.

The shaft130comprises the area126which is defined by the outer race22, inner diameter128of the shaft130and a plug234. In accordance with an embodiment of the disclosure, the inner diameter128of the shaft130is of a length which is substantially constant. It is within the scope of this disclosure that the plug234may solid without any gaps or breaks. As illustrated inFIGS. 1-3, the plug234is located in a space236and extends continuously across to seal against the inner diameter128in an airtight manner and define the area126.

In fluid communication with the area126is a second vent hole238that is also in fluid communication with the atmosphere. The pressure created in the interior82of the constant velocity joint20is vented to the atmosphere via the second vent hole238. Thus, fluid communication is provided between the interior82of the joint assembly20, space92, first vent hole88, area126, second vent hole238and atmosphere to vent pressure thereto.

The second vent hole238is provided in the attachment end40of the outer race22. While one second vent hole238is depicted in theFIG. 1, additional vent holes may be used. The additional vent holes may be circumferentially spaced about the attachment end40or any spacing may be arranged between them. According to an embodiment of the disclosure, the second vent hole238may be fitted with a check valve (not shown) or other covering (not shown) in order to prevent dirt, debris or moisture from entering the joint20and/or clogging the vent holes88,238.

As previously discussed, the lubricant is provided in the joint to lubricate and cool the parts of the constant velocity joint20.FIG. 2depicts an exemplary lubricant fill level240for the constant velocity joint20when the constant velocity joint20is in a static condition. When the constant velocity joint20is in a static condition, the constant velocity joint20is not rotating or not rotating much. It can be appreciated that the lubricant fill level240can vary within different joints for different applications.

FIG. 3of the present disclosure depicts the constant velocity joint20ofFIG. 2in a dynamic condition. In other words,FIG. 3illustrates the lubricant fill level241in the constant velocity joint20when the constant velocity joint20is rotating. As the constant velocity joint20rotates, the centrifugal force F pushes the lubricant into the radially outer portions of the constant velocity joint20.

FIGS. 4, 5A and 5Billustrates another embodiment of the first vent hole242. The first vent hole242may be comprised of a first axially extending channel244having a first diameter D1and a second axially extending channel246having a diameter D2. The second axially extending channel246is directly axially adjacent the first axially extending channel244and is integrally connected to the first axially extending channel244by a radially extending wall248. As illustrated inFIGS. 4 and 5A, the diameter D2of the second axially extending channel246is smaller than the diameter D1of the first axially extending channel244. Both the first axially extending channel244and the second axially extending channel246may be integrally formed as a single unitary piece with the wall portion90of the outer race22of the constant velocity joint20.

According to an embodiment of the disclosure, the axial length of the first axially extending channel244may be greater than the thickness of the wall portion90of the outer race22. In accordance with this embodiment of the disclosure, a first portion250of an outer surface252of the wall portion90may extend in the axial direction. A second portion254of the outer surface252of the wall portion90may extend from the first portion250in the radially inward-direction. The second portion254contacts the second axially extending channel246.

A valve256is at least partially located within the first vent hole242. In accordance with an embodiment of the disclosure, the valve256is located within the second axially extending channel246and at least a portion of the first axially extending channel244.

The valve256comprises four portions: a disk portion258, a breather portion260, a lip portion262and a stopper portion264. According to an embodiment of the disclosure, the four portions of the valve256are integrally formed as a single unitary piece of material. In a non-limiting example, the valve256may be made of a plastic, rubber or an elastomeric material.

As illustrated inFIGS. 5 and 5A, the stopper portion264of the valve256comprises of two portions: a first axial inner portion266and a second axial outer portion268. The first axial inner portion266is at least partially located within the first axially extending channel244so that the channel244is concentric with the first axial inner portion266of the valve256. The second axial outer portion268of the valve256is at least partially located within the second axially extending channel246so that the channel246is concentric with the second axial outer portion268. According to an embodiment of the disclosure, the second axial outer portion268has a smaller diameter than the second axially extending channel246. It is within the scope of this disclosure that there may or may not be a gap that exists between the channel246and the second axial outer portion268of the valve256.

A radially outward extending portion270is located between the first axial inner portion266and the second axial outer portion268of the valve256. The radially outward extending portion270is in direct axial contact with at least a-portion of the radially extending wall248of the first vent hole242. This design prevents the valve256from being pushed into or pulled out of the outer race22.

The first axial inner portion266may have a frusto-conical outer surface that tapers from the outward to the inward direction. Other shapes are permissible as well, including but not limited to cylindrical.

A channel272is located through the valve256. The channel272has a first aperture274in an end surface276of the first axial inner portion266. The channel272extends through at least a portion of the body of the valve256. As illustrated inFIGS. 4, 5A and 5B, a first portion278of the channel272extends axially in the stopper portion264of the valve256, while a second portion280of the channel272that is in fluid communication with the first portion278, extends in a radial direction. A curvilinear elbow282may be used to connect the two portions278and280thereby fluidly connecting the first portion278with the second portion280of the channel272. As illustrated inFIGS. 5 and 5A, the second portion280of the channel272ends at a second aperture284in an outer surface285of the second outer axial portion268of the stopper portion264. The second aperture284may be radially inward from a portion of the second axially extending channel246. Additionally, the second aperture284may be radially inward from the second portion254of the outer surface252of the wall portion90that extends in the radially inward direction. The channel272has a diameter D3where D3<D2<D1. According to an embodiment of the disclosure, there is only a single channel272in the valve256. In accordance with an embodiment of the disclosure (not shown), the valve256may include a plurality of channels.

Located axially adjacent to and extending radially outward from the stopper portion264of the valve256is the disk portion258having an inner surface290and an outer surface291. According to an embodiment of the disclosure, the disk portion258may have an axially inward depression286on an outer surface288.

The breather portion260of the valve256comprises an axially extending ring292having an inner surface294and an outer surface296. According to an embodiment of the disclosure, the thickness between the two surfaces294and296may be the same or it may vary. In accordance with the embodiment of the disclosure where the thickness between the two surfaces is the same, the surfaces294and296are parallel one another and are parallel to the axis38of the constant velocity joint assembly20.

A ring298extends radially inward from the breather portion260of the lip portion262of the valve256. The ring298of the lip portion262of the valve256has an end surface300that directly contacts at least a portion of the outer surface250of the wall portion90. According to an embodiment of the disclosure, at least a portion of the end surface300is in direct contact with at least a portion of the outer surface250of the wall portion90extending in the axial direction. As illustrated inFIGS. 4 and 5A, the wall portion90may extend at a first angle from horizontal.

In accordance with an embodiment of the disclosure, the lip portion262is typically biased into direct contact with at least a portion of the outer surface250of the wall portion90of the outer race22. However, depending on the centrifugal force F and the air pressure P inside the joint20, the lip portion262may be selectively moved in the radially outward direction to release air pressure developed within the constant velocity joint20.

FIG. 6shows an example of a simulated valve performance by speed, pressure and radial press fit at the lip portion298. For ambient temperature conditions in the joint20, such as 23 degrees C., the lip portion298is closed at 0 psi but it can be opened at approximately 3000 rpm and at pressure P3. When the temperature is approximately 100 degrees C. in the joint20, and at a pressure P1, the lip portion298is closed in the range from zero rpm to approximately 3300 rpm, and open at all times above 3300 rpm. When the temperature is approximately 100 degrees C. in the joint20, and at a pressure P2, the lip portion298opens up at approximately zero rpm.

Based on the foregoing, it can be appreciated that lubricant can be prevented from moving through the valve channel272since the valve256is always effectively closed in a static condition of the joint20. It can also be appreciated that since the pressure from within the joint20is appropriately relieved, the boot200will remain in its intended geometry and shape, which maximizes is durability and life. Further, lay using centrifugal force F to help open the valve256during dynamic conditions, the valve256can be opened up at relatively low pressure, which benefits the boot200as mentioned above.

FIGS. 7, 8A and 8Bdepicts another embodiment of a valve302for use with a constant velocity joint20. The valve302and the constant velocity joint20are the same as described above and illustrated inFIGS. 1-5B, except where specifically noted below.

As illustrated inFIGS. 7,8A and 8B, the valve302terminates at the breather portion260and does not have a lip portion. The axially extending ring of the breather260terminates in a radially extending wall304. At least a portion of an edge portion306of the radially extending wall304contacts at least a portion of an outer surface308of the wall portion90. In the depicted, the outer surface308of the wall portion90extends a second angle, where the second angle is at a greater angle from horizontal than the first angle.

FIGS. 9 and 10depict another embodiment of a valve310for use with a constant velocity joint20. The valve310and the joint20are the same as described above and depicted inFIGS. 1-5 and 7-8B, except where specifically noted below.

A radially inward directed rib312is provided on an inner surface314of the outer race22. The rib312is located axially inward from the first axially extending channel244. According to an embodiment of the disclosure, the rib312is located axially inward a sufficient amount so that there is a gap between the rib312and the stopper portion264of the valve310.

The rib312is impermeable, except for an aperture316in its center. As illustrated inFIGS. 9 and 10, the aperture316is axially aligned with the channel272in the valve310. The rib312may have an inner circumferential surface318with a diameter D4that is smaller than the diameter D3of the channel272of the valve310. The smaller diameter D4of the rib312is designed to reduce the flow of lubricant through the channel272by at least partially blocking the channel272. In addition, the rib312can be used to reduce, or prevent, lubricant from flowing out of the joint20if the valve310were to fall out or otherwise fail.

FIGS. 11 and 12depict a yet another embodiment wherein the valve302ofFIGS. 7, 8A and 8Bas used with the rib312described above and depicted inFIGS. 9 and 10of the disclosure.

FIGS. 13 and 14depict still yet another embodiment wherein the valve256ofFIGS. 4, 5A and 5B, and described above is utilized with an additional feature. As illustrated inFIGS. 13 and 14of the disclosure, the additional feature is a radially inwardly directed protrusion320on the ring298of the lip portion262of the valve256. In accordance with this embodiment of the disclosure, only the protrusion320directly contacts at least a portion of the outer surface250of the wall portion90of the outer race22. As a result, a gap322exists between the ring298of the lip portion262and the outer surface250of the wall portion90of the outer race22. The protrusion320permits pressure to escape more easily as compared with when the entire lip portion262is in direct contact with at least a portion of the outer race22. Pressure escapes more easily by bypassing the protrusion320since it has less material to move as compared with the entire lip portion262.

In addition, the wall portion90of the outer race22is provided with an additional feature. As illustrated inFIG. 13, the outer race22of the constant velocity joint20includes a radially inward directed step324on the inner surface314of the wall portion90of the outer race22. According to an embodiment of the disclosure, the step324may axially encroach on the first axially extending channel244. In this embodiment, the step324may be located directly adjacent the frusto-conical surface of the stopper portion264. As illustrated inFIG. 13of the disclosure, an inner edge portion326of the step324may be located directly adjacent the frusto-conical surface of the stopper portion264. The step324may extend axially beyond the stopper portion264of the valve256. In accordance with an embodiment of the disclosure, the step324has an inner circumferential diameter D5that is smaller than the diameters D1of the first axially extending channel244. Additionally, the inner circumferential diameter D5of the step324is larger than the diameter D2of the second axially extending channel246. In accordance with an alternative embodiment of the disclosure (not shown), the inner circumferential diameter of the step is smaller than the diameter of the second axially extending channel.

FIGS. 15 and 16depict a further embodiment wherein the valve256ofFIGS. 13 and 14with the protrusion320is utilized. Additionally, as illustrated inFIG. 15, the rib312ofFIGS. 9 and 10is also utilized as well. The benefits and functions described above for the embodiments inFIGS. 9, 10, 13 and 14are had in this embodiment of the disclosure as well. As illustrated inFIG. 15, the step324is located axially outward from the rib312such that the step324is located between the first axially extending channel244and the rib312on the wall portion90of the outer race22. As previously discussed the smaller diameter D4of the rib312is designed to reduce the flow of lubricant through the channel272by at least partially blocking the channel272. Additionally, as illustrated inFIG. 15, the diameter D4of the rib312has a diameter that is smaller than the diameters D3, D2and D1such that D4<D3<D2<D1.

The valve256,302and310previously discussed and illustrated inFIGS. 4-5B and 7-16is designed to seal the vent hole242and prevent the lubricant from escaping the constant velocity joint20when the joint20is in a static condition. Additionally, the valve256,302and310is designed to vent air from within the constant velocity joint20when the pressure within the joint20reaches an undesirable level, whether the joint20is in a static or a dynamic condition.

In order for the valve256,302and310to seal the vent hole242when the constant velocity joint20is in a static condition, an amount of sealing force needed to seal the lubricant within the joint20needs to be determined. Once the sealing force is determined, at least a portion of the breather portion260and/or the lip portion262, of the valve256,302and310applies the pre-determined amount of sealing force onto at least a portion of the outer surface252of the wall portion90of the outer race22of the joint20.

As previously discussed, the valve256,302and310is also designed to vent an amount of air from within the constant velocity joint20when the pressure within the joint20reaches an undesirable level. In order to vent an amount of air from within the constant velocity joint20, an undesirable constant velocity joint static condition internal air pressure and an undesirable constant velocity joint dynamic condition internal air pressure needs to be determined.

As the air pressure P builds up within the constant velocity joint20, the air within the constant-velocity joint20applies a radial and/or an axial force onto the disk portion258, the breather portion260and/or the lip portion262of the valve256,302and310. When the constant velocity joint20is in a static condition, and the air pressure P within the joint20reaches the pre-determined undesirable constant velocity joint static condition air pressure, the valve256,302and310opens venting an amount of air from within the joint20to the atmosphere. Once the internal air pressure P within the constant velocity joint20falls below the pre-determined undesirable constant velocity joint static condition air pressure, the biasing force of the valve256,302and310closes and seals the valve256,302and310.

When the constant velocity joint20is in a dynamic condition, and the air pressure P builds up within the joint20, the air within the joint20applies a radial and/or an axial force onto the disk portion258, the breather portion260and/or the lip portion262of the valve256,302and310. Additionally, when the constant velocity joint20is in a dynamic condition, a centrifugal force F is applied onto the disk portion258, the breather portion260and/or the lip portion262of the valve256,302and310. Once the internal air pressure P within the pre-determined undesirable constant velocity joint dynamic condition air pressure is reached, the valve256,302and310opens venting an amount of air from within the joint20to the atmosphere. When the internal air pressure P within the constant velocity joint20falls below the pre-determined undesirable constant velocity joint dynamic condition air pressure, the biasing force of the valve256,302and310closes and seals the valve256,302and310.

By utilizing the centrifugal force F exerted on the valve256,302and310when the valve256,302and310is in a dynamic condition, it allows the valve256,302and310to open and vent the constant velocity joint20at a lower air-pressure P than when the joint20is in a static condition. This aids in increasing the life and durability of the boot assembly34.