Tire inflation system

Abstract

In one aspect, a swivel joint for a wheel end system includes a wheel hub having a passageway. The rotary joint includes a pressurized air receiver configured to be mounted to a vehicle spindle, an air inlet of the pressurized air receiver, a pressurized air distributor rotatable about an axis relative to the pressurized air receiver, and an air outlet of the pressurized air distributor. The pressurized air distributor is configured to be mounted to and rotate with a wheel hub. The rotary joint also includes a seal axially spaced from the air inlet such that the seal and the air inlet are offset from each other along the vehicle main shaft. The seal is transitionable from a disengaged configuration to an engaged configuration to allow pressurized air received at the air inlet of the pressurized air receiver to flow to the air outlet of the pressurized air distributor.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 399,375, filed on August 19, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to vehicles, and more particularly to tire inflation systems for vehicles. Background Art

[0003] Vehicle tires are designed to operate at a predetermined internal pressure. Insufficient tire pressure is a leading cause of tire wear and failure on all types of vehicles. Commercial vehicles, such as those described by the Federal Highway Administration (FHWA) as Class VII or higher, use large tires to support the loads carried by commercial vehicles. Commercial vehicles can include tractors (sometimes called semi-trailer trucks), trailers, and heavy trucks.

[0004] Tire pressure maintenance is a known problem within the commercial vehicle industry, as a significant maintenance expense for commercial fleets is the cost of tires. Tire pressure maintenance is particularly problematic for tractor-trailer fleets, as each tractor may have two steer tires and eight drive tires, and each trailer may have eight tires.

[0005] There are several approaches to solving the problem of underinflation of trailer tires. One automatic tire inflation system utilizes a small air seal to receive pressurized air that is supplied through the center of the trailer axle. The pressurized air is then transferred from the air seal to the hub cap of the associated wheel and finally to the tire of the wheel. The automatic tire inflation system continuously inflates the tire at a set pressure while the vehicle's pneumatic system is operating, maintaining the tire at a minimum tire pressure.

[0006] The drive shaft of a tractor or other commercial vehicle consists of a main shaft with half shafts extending inside it. The drive wheel hub is mounted on the main shaft, and the drive flange of the half shaft is fixed to the outboard end of the drive wheel hub by the studs of the wheel hub. Due to the presence of the rotating half shaft in the main shaft and the drive flange fixed to the outboard end of the drive wheel hub, it is impossible to use a traditional tire inflation system that transmits pressurized air through the main shaft to the wheel hub cap.

[0007] U.S. Patent No. 11,254,170 discloses an automatic tire inflation system with air supplied through a wheel hub. The automatic tire inflation system includes a spindle having a passage formed therein for receiving pressurized air. The spindle passage directs the pressurized air radially outward into a grease reservoir between bearings of a combined bearing connecting a wheel hub to the spindle. A rotating air seal causes the pressurized air to flow from the spindle passage to the wheel hub passage. However, the automatic tire inflation system of U.S. Patent No. 11,254,170 requires a specialized vehicle spindle that includes a passage for receiving pressurized air. The passage in the spindle may present difficulties when forming the passage in the side wall of the spindle. Another problem with the system in U.S. Patent No. 11,254,170 is that positioning the rotating air seal in the grease reservoir exposes the rotating air seal to potential failure modes associated with debris and oil foam in the grease reservoir. In addition, gas leakage from the rotating air seal may cause the oil seal of the wheel hub to be compressed and associated damage and / or oil leakage. Summary of the invention

[0008] In one aspect of the present disclosure, a rotary joint for a wheel end system is provided, the wheel end system including a wheel hub having a passage. The rotary joint includes a pressurized air receiver configured to be mounted to a vehicle spindle and having an air inlet of the pressurized air receiver. The rotary joint also includes a pressurized air distributor rotatable about an axis relative to the pressurized air receiver. The pressurized air distributor is configured to be mounted to the wheel hub and rotate therewith. The pressurized air distributor has an air outlet for directing pressurized air to the passage of the wheel hub. The pressurized air receiver and the pressurized air distributor have a seal axially spaced from the air inlet of the pressurized air receiver, so that when the pressurized air receiver is mounted to the vehicle spindle and the pressurized air distributor is mounted to the wheel hub, the seal and the air inlet are offset from each other along the vehicle spindle. The seal can be transformed from a disengaged configuration to an engaged configuration to allow pressurized air received at the air inlet of the pressurized air receiver to flow to the air outlet of the pressurized air distributor. Since the pressurized air receiver is configured to be mounted to a vehicle spindle, the rotary joint may be mounted to the vehicle spindle and provide an interface for communicating pressurized air between the vehicle pressurized air supply and a passageway of a rotatable wheel hub.

[0009] In another aspect of the present disclosure, a wheel hub is provided, which includes a wheel hub body and an inner bearing and an outer bearing to rotatably mount the wheel hub body to a vehicle spindle. The wheel hub includes a pressurized air passage associated with the wheel hub body, which can rotate with the wheel hub body around the vehicle spindle. The wheel hub also includes a rotary joint located inside the inner bearing. The rotary joint has an air inlet for receiving pressurized air and an air outlet for directing pressurized air to the pressurized air passage. The air outlet can rotate with the wheel hub body around the vehicle spindle. The rotary joint has a seal that is operable to pneumatically connect and disconnect the air inlet and air outlet of the rotary joint. In this way, the wheel hub provides a rotary joint that is operable to selectively establish a pressurized air flow path while being located inside the inner bearing and its lubricant, which can prevent the lubricant of the inner bearing from contaminating the seal of the rotary joint.

[0010] The present invention also provides a diaphragm seal. The diaphragm seal includes an annular diaphragm having a groove for receiving pressurized air and an air outlet for allowing pressurized air to flow out of the diaphragm. The diaphragm has a contact portion configured to move toward a sealing surface in a first radial direction in response to the groove receiving pressurized air. The contact portion is configured to move away from the sealing surface in an opposite second radial direction when pressurized air is no longer provided to the groove of the diaphragm. The contact portion has a protrusion configured to engage with the sealing surface when the contact portion moves along the first radial direction. The protrusion of the diaphragm concentrates the pressure from the pressurized air in the groove of the diaphragm, thereby firmly sealing the diaphragm on the sealing surface. In addition, the diaphragm seal allows the associated system to control the engagement or disengagement of the diaphragm with the sealing surface by applying or not applying pressurized air to the groove of the diaphragm. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a perspective view of a wheel end system for a commercial vehicle including a wheel hub mounted to a spindle;

[0012] Figure 2 is along Figure 1 A cross-sectional view taken along line 2-2 in Figure 1, showing an air seal cartridge inboard of an inboard bearing assembly of a wheel hub having a wheel hub body with a passageway for directing air from the air seal cartridge to an exterior port of the wheel hub;

[0013] Figure 3 yes Figure 2 a perspective view of an air seal cartridge showing a radially inner non-rotatable pressurized air receiver having a pressurized air inlet and a radially outer rotatable pressurized air distributor directing pressurized air to a wheel hub passage;

[0014] Figure 4 yes Figure 2 an enlarged view of the middle dashed area showing the diaphragm seal of the air seal cartridge in a disengaged configuration;

[0015] Figure 5 is with Figure 4 a similar view showing the diaphragm seal in an engaged configuration and the flow of air from the non-rotatable pressurized air receiver to the rotatable pressurized air distributor and into the wheel hub passage;

[0016] Figure 6 yes Figure 5 a perspective view of a non-rotatable pressurized air receiver showing a diffuser ring having an opening with a diaphragm member on either side of the opening having a ridge for engaging a sealing ring of a rotatable pressurized air distributor;

[0017] Figure 7 is a perspective view of another air seal cartridge having a non-rotatable air receiver having an air inlet for receiving pressurized air and a rotatable air distributor having an air outlet for directing the pressurized air into a wheel hub passage;

[0018] Figure 8 yes Figure 7 Cross-sectional view of the air seal cartridge installed between the wheel hub and the spindle, Figure 8 An end face seal of an air seal cartridge is shown in a disengaged configuration;

[0019] Fig. 9 is similar to Figure 8 a cross-sectional view of the embodiment of the present invention showing the face seal in an engaged configuration and the passage of air from the non-rotatable pressurized air receiver of the air seal cartridge into the rotatable pressurized air distributor of the air seal cartridge and into the wheel hub;

[0020] Fig.10 yes Fig. 9 a cross-sectional perspective view of a non-rotatable pressurized air receiver showing a passage formed between a sealing member and a sealing ring, the passage receiving a rotatable sealing member of a rotatable pressurized air distributor;

[0021] Fig.11 is a schematic diagram of a tire pressure system according to one embodiment of the present disclosure;

[0022] Fig.12 yes Fig.11 A flowchart of a method of operating a tire pressure system of the invention, including parameters, conditions and responses associated with the method;

[0023] Fig.13yes Fig.11 A flowchart of a method of operating a tire pressure system;

[0024] Fig.14 is a cross-sectional view of another embodiment of a diaphragm seal in a disengaged configuration;

[0025] Fig.15 It is shown Fig.14 A cross-sectional view of a diaphragm seal in an engaged configuration;

[0026] Fig.16 is a cross-sectional view of another embodiment of a diaphragm seal in a disengaged configuration;

[0027] Fig.17 It is shown Fig.16 A cross-sectional view of a diaphragm seal in an engaged configuration;

[0028] Fig.18 is a cross-sectional view of an air seal cartridge having a lip seal;

[0029] Fig.19 is a cross-sectional view of an air seal cartridge having a lip seal;

[0030] Fig. 20 is a cross-sectional view of an air seal cartridge having a lip seal;

[0031] Fig.21 is a cross-sectional view of an air seal cartridge having a diaphragm seal;

[0032] Fig. 22 is a cross-sectional view of a diaphragm seal in a disengaged configuration, wherein the diaphragm is spaced apart from the sealing surface;

[0033] Figure 23 to Figure 26 When pressurized air is applied to the cavity of the diaphragm seal and the diaphragm of the diaphragm seal engages with the sealing surface Fig. 22 A cross-sectional view of a diaphragm seal;

[0034] Fig. 27 yes Fig. 22 a cross-sectional view of a diaphragm seal of , showing the diaphragm seal at a temperature of 300° F. and in a disengaged configuration;

[0035] Figure 28 to Figure 31 yes Fig. 27 a cross-sectional view of a diaphragm seal of , showing a cavity of the diaphragm seal receiving pressurized air and the diaphragm engaging a sealing surface;

[0036] Fig.32 yes Fig. 22a cross-sectional view of a diaphragm seal of , showing the diaphragm seal at a temperature of -40°F and in a disengaged configuration;

[0037] Fig.33 is a cross-sectional view of an air seal cartridge having a diaphragm seal; and

[0038] Fig.34 yes Fig.33 A perspective view of the diaphragm of an air seal cartridge showing the nozzle of the diaphragm. DETAILED DESCRIPTION

[0039] refer to Figure 1 and Fig.11 , a tire inflation system 600 is provided, which includes a wheel end system 10, which has a wheel hub assembly 12 mounted to a spindle 14. The wheel hub assembly 12 includes a wheel hub body 16, and the wheel hub body 16 has a mounting portion, such as a mounting flange 18, which is configured to mount a wheel thereon. As some examples, the mounting flange 18 may include a stud to mate with an opening of a wheel, or include an opening for receiving a wheel stud. The wheel hub body 16 and the wheel mounted thereto are rotatable about a central axis 20 of the wheel hub assembly 12. The wheel hub assembly 12 is used for a drive wheel of a vehicle and includes an axle bolt boss 22 that supports an axle bolt 24 of the wheel hub assembly 12. The axle stud 24 extends through a through hole of a drive flange 26 that drives an axle shaft (such as a half shaft 28) (see Figure 2 As the half shaft 28 rotates, the engagement between the axle bolt 24 and the drive flange 26 causes the wheel hub body 16 to rotate about the central axis 20 .

[0040] like Figure 1 and Figure 2 As shown, the wheel hub body 16 includes a passage 34 having an external port (eg, outlet port 30) at an outer surface 32 of the wheel hub body 16. The passage 34 also includes an internal port, such as inlet port 36, at an inner surface 38 of the wheel hub body 16. Figure 2 The wheel hub assembly 12 includes a rotary joint, such as an air seal 40. The air seal 40 receives pressurized air from a vehicle supply 48 (see Fig.11 ) receives pressurized air and communicates the pressurized air to the passageway 34 of the wheel hub body 16. The passageway 34 directs the pressurized air to the air distribution system 604 (e.g., one or more pipes, valves, and / or fittings that conduct the pressurized air to the tire 606 of the associated wheel).

[0041] refer to Figure 2 and Figure 3, the air seal cartridge 40 includes a wheel-end pressurized air supply arrangement, such as a non-rotatable pressurized air receiver 42 mounted to the spindle 14 and a rotatable pressurized air distributor 60 mounted to the wheel hub body 16. As used herein, the term "rotatable" refers to a component that rotates with the rotation of the associated wheel during normal vehicle operation, and the term "non-rotatable" refers to a component that does not rotate with the rotation of the associated wheel during normal vehicle operation.

[0042] The non-rotatable pressurized air receiver 42 has a body 44 with a central opening 45 for receiving the spindle 14. The body 44 has an air inlet 46 which receives pressurized air from a vehicle pressurized air supply 48 (see Fig.11 ). The vehicle pressurized air supply 48 may include, for example, a valve 49 operably connected to the air inlet 46, a reservoir 50, and a pump 52. The pump 52 pressurizes the air in the reservoir 50 and allows the pressurized air to flow into the air inlet 46 of the non-rotatable pressurized air receiver 42 when the valve 49 is opened.

[0043] As discussed in more detail below, the air seal cartridge 40 includes a seal, such as a diaphragm seal 200 (see Figure 4 ), which has an engaged configuration in which the diaphragm seal 200 allows pressurized air applied to the air inlet 46 to flow to the wheel hub passage 36; and a disengaged configuration in which the diaphragm seal 200 limits contact between the various parts of the diaphragm seal 200. In one embodiment, the diaphragm seal 200 has a rotatable component and a non-rotatable component, which contact each other to form a pressurized air flow path when the diaphragm seal 200 is pressurized, and there is a gap between the components when the diaphragm seal 200 is not pressurized.

[0044] When pressurized air is applied to the air inlet 46, the diaphragm seal 200 transitions from the disengaged configuration to the engaged configuration. The vehicle includes an electronic control unit, such as the electronic control unit 630 (see Fig.11 ), which opens valve 49 to direct pressurized air to air inlet 46 or closes valve 49 to inhibit pressurized air from flowing into air inlet 46. Electronic control unit 630 opens valve 9 when one or more conditions are met, such as a tire underinflation condition (e.g., tire pressure is lower than a predetermined tire pressure) and a vehicle speed condition (e.g., vehicle speed is lower than a predetermined vehicle speed). In one embodiment, when the tire pressure of tire 606 is lower than the predetermined tire pressure and the vehicle is stationary, electronic control unit 630 opens valve 49 and transitions diaphragm seal 200 from a disengaged configuration to an engaged configuration. By transitioning diaphragm seal 200 to an engaged configuration when the vehicle is stationary, friction between components of diaphragm seal 200 is limited, which improves the durability of diaphragm seal 200.

[0045] Back to Figure 3 The rotatable pressurized air distributor 60 is configured to be mounted to the inner surface 38 of the wheel hub body 16 and rotate with the wheel hub body 16 about the central axis 20. The rotatable pressurized air distributor 60 has a pressurized air outlet 67, which is configured to guide the pressurized air into the passage 67 of the wheel hub body 16. The rotatable pressurized air distributor 60 has a sleeve mount 62, which can be made of a polymer such as rubber, for engaging the radial inner surface 63 of the wheel hub body 16 (see Figure 4 ). The sleeve mount 62 has one or more sealing members, such as ridges 64 separated by grooves 66 (see Figure 5 ), which extends around an opening 68 of the sleeve mount 62, which is radially aligned with the inner port 36 of the passageway 34. The ridge 64 forms a seal with the radial inner surface 63 of the wheel hub body 16 to inhibit air leakage between the sleeve mount 62 and the wheel hub body 16.

[0046] The rotatable pressurized air distributor 60 also includes a sealing sleeve 70, which may be made of a metallic material. In one embodiment, the sleeve mount 62 is molded onto the sealing sleeve 70. The sealing sleeve 70 has an outlet opening 72 that leads to the opening 68 of the sleeve mount 62. As discussed in more detail below, when the diaphragm seal 200 is in a sealed configuration or an engaged configuration, pressurized air received at the air inlet 46 of the non-rotatable pressurized air receiver 42 is directed through the outlet opening 72 of the sealing sleeve 70, through the opening 68 of the sleeve mount 62, and into the passageway 34. The pressurized air is directed in a direction 80 (see FIG. 2 ). Figure 2 ) flows through passage 34 to external port 30. In one embodiment, air distribution system 604 includes a fitting that engages external port 30 and a conduit with a one-way valve that connects the fitting to tire 606. In this way, even though drive axle shaft 28 extends into interior 90 of main shaft 14, air seal cartridge 40 can still deliver pressurized air to the tire of a wheel mounted to wheel hub assembly 12.

[0047] refer to Figure 2 The hub assembly 12 includes an outer bearing (e.g., outer bearing assembly 100), an inner bearing (e.g., inner bearing assembly 102), a spacer 104, and a grease container 105. The inner bearing assembly 100 and the outer bearing assembly 102 each include a cone 106, a cup 108, and bearing elements (e.g., rollers 110) that roll along the raceways of the cone 106 and the cup 108. In one embodiment, lubricant is allowed to flow from the interior 123 of the main shaft 14 to contact the inner bearing assembly 102 and the outer bearing assembly 108. The inner lubricant seal 120 (see Figure 4) inhibits lubricant from flowing inwardly from the inner bearing assembly 102. In this way, the inner lubricant seal 120 keeps the air seal sleeve 40 free of lubricant from the inner bearing assembly 102. The lubricant may include, for example, oil or grease.

[0048] The wheel hub system 12 also includes a spindle locking nut 114 to secure the wheel hub system 12 to the spindle 14. Specifically, the spindle locking nut 114 has threads to engage with threads of the spindle 14. The spindle locking nut 114 is tightened onto the spindle 104 to push the inner and outer bearing assemblies 102, 108, the spacer 104, and the air seal cartridge in the inboard direction 127. In this manner, the wheel hub assembly 12 can be installed on the spindle 14 by positioning the wheel hub assembly 12 on the spindle 14 and tightening the spindle locking nut 114 to secure the wheel hub assembly 12 to the spindle 14. Once the wheel hub assembly 12 has been installed on the spindle 14, the shaft portion 28A of the half shaft 28 is pushed into the interior 123 of the spindle 14 in the inboard direction 127, and the drive flange 26 of the half shaft 28 is connected to the axle bolt 24. In one embodiment, the spindle locking nut 114 includes a retainer assembly that prevents the spindle locking nut 114 from accidentally loosening on the spindle 14 .

[0049] refer to Figure 2 The wheel hub body 16 has an inner end section 131 with an inner end 133, an outer end section 135 with an outer end 137, and a central opening 139 extending from the inner end 133 to the outer end 137. The wheel hub system 12 includes a circular brake element, such as a drum or brake disc 133A, mounted thereon. During assembly of the wheel hub assembly 12, including its inner lubricant seal 120 (see Figure 4 ) is advanced into the central opening 139 of the wheel hub body 16 in the outboard direction 129. In this manner, the air seal cartridge 40 provides an integrated assembly including the inboard lubricant seal 120 that can be easily mounted to the wheel hub body 16.

[0050] The air seal cartridge 40 has a diaphragm seal 200 having a Figure 4 The gap configuration or disengagement configuration shown, and Figure 5The diaphragm seal 200 includes one or more diaphragm members, such as diaphragms 202, 203, which allow the diaphragms 202, 203 to expand radially when the diaphragm seal 200 is inflated. The diaphragms 202, 203 have ridges 204, 206, which are spaced apart from the rotatable sealing surface 210 of the sealing sleeve 70 when the diaphragm seal 200 is in the disengaged configuration, and the ridges 204, 206 engage the rotatable sealing surface 210 when the diaphragm seal is in the engaged configuration.

[0051] about Figure 5 and Figure 6 The non-rotatable pressurized air receiver 42 includes a mounting ring 304, diaphragm support rings 322, 324, a diffuser ring 230, and a diaphragm support base 246, which are used to secure the diaphragms 202, 203 to the body 44 and limit the expansion of the diaphragms 202, 203 to radial expansion and contraction when the diaphragm seal 200 is switched between the engaged configuration and the disengaged configuration. In other embodiments, the non-rotatable pressurized air receiver 42 can guide one or more diaphragm components to move along different paths (e.g., axially or obliquely to the rotational axis of the wheel hub body 16).

[0052] about Figure 6 The diaphragm seal 200 includes a diaphragm chamber 252 generally formed between the diaphragms 202, 203, the diffuser ring 230, and the diaphragm support base 246. The diaphragm support base 246 has openings 248, 250 that are radially aligned with the ridges 204, 206 of the diaphragms 202, 203. The body 44 has a passage 240 with an outlet 242 that pneumatically connects the air inlet 46 and the diaphragm chamber 252. When pressurized air is introduced into the diaphragm chamber 252, the internal air pressure of the diaphragm chamber 252 is higher than the radial outer surfaces 254, 255 of the diaphragm 202 (see Figure 5 and 6 ), which causes the diaphragms 202, 203 to bulge radially outward and engage with the sealing sleeve 70. More specifically, as shown by comparing Figure 4 and Figure 5 It can be seen that the pressure differential across the diaphragms 202, 203 causes the portions 260, 262 of the diaphragms 202, 203 to flex and move the ridges 204, 206 radially outward into sealing engagement with the rotatable sealing surface 210 of the sealing sleeve barrel 70. The ridges 204, 206 engage the sealing sleeve 70 and form two parallel sealing engagement lines on either side of the diffuser ring 230. Figure 6The ridges 204, 206 of the diaphragms 202, 203 protrude from the radially outer surfaces 254, 255 and provide a smaller contact surface area with the sealing sleeve 70, which increases the sealing force between the diaphragms 202, 203 and the sealing sleeve 70. Specifically, the contact pressure of the seal formed by the ridges 204, 206 is greater than the gas pressure in the diaphragm chamber 252.

[0053] refer to Figure 6 , the diaphragm support rings 322, 324 have grooves 350, 352, each of which receives a lip 354, 356 of a base flange portion 358, 360 of the diaphragm 202, 203. The lips 354, 356 are sandwiched in the grooves 350, 352 of the diaphragm support rings 322, 324, located between the flange 360 ​​of the diaphragm support rings 322, 324 and the mounting rings 304, 320. The diaphragm support rings 322, 324 secure the diaphragm base portion 358, 360 to the body 40, thereby forming a static seal between the diaphragm 202, 203 and the body 40. In one embodiment, the diaphragm support rings 322, 324 can include a split ring and a flexible member (e.g., plastic or hard rubber) to hold the ends of the split ring together. The flexible member allows the ends of the split ring to be controlled to separate or merge during operation and limit binding under high load conditions.

[0054] In one embodiment, the mounting rings 304, 320 have an inner diameter that is sized to form an interference fit with the body 40 to secure the mounting rings 304, 320, the diaphragm support rings 322, 324, and the diaphragm support base 248 in place along the body 40. In addition, the diaphragm support base 248 maintains the axial spacing between the diaphragm base flange portions 358, 360, the diaphragm support rings 322, 324, and the mounting rings 304, 320.

[0055] The diaphragms 202, 203 are made of a resilient material, such as a polymer (e.g., rubber or silicone) to allow the ridges 204, 206 to shift into sealing engagement with the sealing sleeve 70. Various materials may be used for the diaphragms 202, 203, such as hydrogenated nitrile rubber (HNBR), fluoroelastomers, fluorocarbons, silicones, and / or ethylene acrylate elastomers. The mounting rings 304, 320 and the diaphragm support rings 322, 324 are made of a rigid material, such as a metallic material such as steel or aluminum, which has sufficient rigidity to resist axial separation or bending of the diaphragm support rings 322, 324 when the diaphragm chamber 252 is pressurized. In contrast, the diaphragm support rings 322, 324 guide the contact portions 370, 372 of the diaphragm 202 radially outward. Figure 6In the embodiment of the present invention, each diaphragm 202, 203 is connected to the diffuser ring 230 by a groove 376 that receives the flange 377 of the diffuser ring 230. The diffuser ring 230 can be made of a rigid material (such as steel or aluminum or plastic), and the diaphragms 202, 203 are molded onto the diffuser ring 230.

[0056] In one embodiment, the diaphragms 202, 203 are made of a flexible material and a spring biases the diaphragms 202, 203 toward their gap positions. For example, the diaphragms 202, 203 may each include an elastic material for providing a sealing engagement and a spring overmolded with the elastic material, such as a metal or plastic spring. Pressurized air is introduced into the diaphragm chamber 252 to overcome the spring biasing force and displace the diaphragms 202, 203 into sealing engagement with the sealing sleeve 70.

[0057] about Figure 5 , diaphragm seal 200 is shown in a sealed or engaged configuration wherein surface portions 220, 222 of ridges 204, 206 of diaphragms 202, 203 are securely engaged with rotatable sealing surface 210 of sealing sleeve 70, which forms an annular space 224 between diaphragms 202, 203, sealing sleeve 70, and diffuser ring 230. Diffuser ring 230 has a through hole 270 leading to annular space 224 and diaphragm chamber 252. Pressurized air introduced into air inlet 46 passes through passage 240, through holes 248, 250, through hole 270, annular space 224, opening 72, opening 68, and into passage 34 and then into the tire of the associated wheel. In this manner, application of pressurized air at the air inlet 46 causes the diaphragms 202, 203 to seal relative to the sealing sleeve 70 and causes pressurized air to flow from the air inlet 46 into the passage 34 of the wheel hub body 16 to increase the tire pressure of the tire associated with the wheel hub body 16. The operability of the diaphragm seal 200 to transition to an engaged configuration and deliver pressurized air to the wheel hub passage 34 in response to application of pressurized air at the air inlet 46 allows the diaphragm seal 200 to be controlled by operating the valve 49, which can be positioned away from the road environment to improve the durability of the system.

[0058] In one embodiment, the electronic control unit 630 is configured to inflate a tire associated with the wheel hub assembly 12 only when the vehicle speed is less than a threshold value (e.g., less than five miles per hour). The electronic control unit 630 thereby prevents the diaphragms 202, 203 from engaging the sealing sleeve 70 at higher vehicle speeds (e.g., highway speeds), which may generate high friction and operating temperatures, thereby potentially shortening the service life of the diaphragms 202, 203. When the diaphragm seal 200 is in the disengaged configuration, the diaphragms 202, 203 are subject to less friction and temperature-related wear during rotation of the wheel hub body 16 about the spindle 14 due to reduced contact between the diaphragms 202, 203 and the sealing sleeve 70. Depending on the particular embodiment of the air seal cartridge 40, the diaphragms 202, 203 may be completely separated from the sealing sleeve 70, or may be in light contact with the sealing sleeve 70, when the diaphragm seal 200 is in the disengaged configuration.

[0059] The wheel hub body 16 may have one passage 34, and the air seal cartridge 40 may have one pressurized air outlet 67 to provide pressurized air to the passage 34, for example, if the wheel mounted to the wheel hub body 16 has a single tire. In another embodiment, the wheel hub body 16 includes two passages 34, the air seal cartridge 40 has two pressurized air outlets 67, and the air distribution system 604 includes two pressurized air lines for providing pressurized air to the tires 606. The air distribution system 604 may also include valves associated with the air lines that are individually operable to allow pressurized air to flow into one or both tires on the wheel hub rim, depending on the air pressure level in the tires 606. Different pressures may be applied to different tires by closing the valve associated with one tire and opening the valve associated with the tire that requires further pressurization. The air distribution system 604 may include mechanical controls and / or digital controls. In one embodiment, the air distribution system 604 may include a pressure relief valve to release the air pressure in one or more tires 606 when the tire pressure is too high.

[0060] refer to Figure 4 , the air seal cartridge 40 has an air leakage path 310 that allows pressurized air to exit the air seal cartridge 40 if the diaphragm 202 fails, rather than allowing the pressurized air to damage the inner lubricant seal 120, which maintains the operability of the inner and outer bearings 100, 102 despite the inoperability of the diaphragms 202, 203. More specifically, if either of the diaphragms 202, 203 fails to engage the sealing sleeve 70, pressurized air can exit the opening 270 of the diffuser ring 230 (see Figure 5) and travels in direction 300 into gap 302 between mounting ring 304 and contaminant seal 160. The pressurized air in gap 302 forces lip 166 of contaminant seal 160 tightly against flange 168 of lubricant sealing sleeve 122. Lip 166 directs the pressurized air in direction 306 into radial passage 307 of spindle mount 134. The pressurized air travels axially through air outlet passage 308 (see Figure 3 ), and along the tapered radially outer surface 312 of the main shaft 14 and through the contaminant seal 316. The air can then be exhausted from between the contaminant seal 316 and the main shaft 14. The contaminant seal 316 allows air to flow out along the air leakage path 310 while inhibiting contaminants from entering the interface between the body 44 and the main shaft 14.

[0061] Continue to refer Figure 4 , the inner lubricant seal 120 includes a lubricant sealing sleeve 122, which may be made of a metallic material such as steel or aluminum, and a spindle mounting seal 124, which may be made of an elastic material such as rubber. A ring 126 is fixed to the lubricant sealing sleeve 122, which forms a tortuous path for the lubricant. The spindle mounting seal 124 has grooves 128 and ribs 131, which engage with corresponding ribs 132 and grooves 130 of a spindle mounting 134 fixed to the body 44. The spindle mounting seat 134 has radial inner ridges 135, which are separated by channels 308 that abut against the spindle 14. The ribs 131 and ridges 132 overlap in the axial direction and inhibit relative axial movement of the body 44 and the lubricant sealing sleeve 122, which inhibits axial separation of the inner lubricant seal 120 from the body 44. In one embodiment, the ribs 131 may include a rigid material (e.g., steel) that engages with the grooves 128.

[0062] The inner lubricant seal 120 also includes a sealing shell 140 having a sealing body 142 that may be made of a metallic material, such as aluminum, and a sealing element 144 that may be made of a polymer material, such as rubber. The sealing element 144 has a radially outer portion that engages the radially inner surface 63 of the wheel hub body 16 and a radially inner portion that includes a lip seal 146. The lip seal 146 has a sealing portion 148 that engages the radially outer surface 149 of the lubricant sealing sleeve 122. In one embodiment, the inner lubricant seal 120 has an annular spring that urges the sealing portion 146 to engage the lubricant sealing sleeve 122.

[0063] refer to Figure 4, the air seal cartridge 40 has a predetermined lubricant leakage path 150 so that lubricant can leave the air seal cartridge 40 when the lubricant seal 120 fails and can be visually detected by a technician on an outer surface (e.g., surface 152) of the hub assembly 12. More specifically, the rotatable pressurized air distributor 60 includes a contaminant seal 160 fixed to a radial inner surface 162 of the sealing sleeve 70. The contaminant seal 160 includes a first sealing member (e.g., lip 164) engaged with the sealing element 144 and a second sealing member (e.g., lip 166) engaged with a flange 168 of the lubricant sealing sleeve 122. The lips 164, 166 guide the lubricant to flow along the lubricant leakage path 150 while preventing the lubricant from contaminating the diaphragm seal 200. For example, if the lip seal 146 has worn and is spaced apart from the lubricant seal set 122, lubricant may flow between the sealing element 144 and the lubricant sealing sleeve 122 in directions 170, 172. The force acting on the lubricant during rotation of the wheel hub 16 urges the lubricant in direction 174 to flow under the lip 164 and into the opening 176 in the sealing sleeve 70. The outflowing lubricant enters the outlet passage 178 (see FIG. Figure 3 ) and ultimately exits through opening 180 between sleeve mount 62 and radially inner surface 63 of wheel hub body 16. Lubricant may then flow radially outward along surface 152, which provides a visual indication that the inboard lubricant seal 120 has failed. Alternatively or additionally, one or more holes may be formed in wheel hub body 16 that allow oil to flow outward therethrough and provide a visual indication of an inboard lubricant seal failure.

[0064] refer to Figure 4 and 5 , the air seal cartridge 40 includes a contaminant seal 389 to prevent contaminants from entering the air seal cartridge 40. In one embodiment, the contaminant seal 389 includes a sealing member 392 formed integrally with the sleeve mount 62. The sealing member 392 has a lip 394 that engages an outer surface 396 of a sealing ring 398. The sealing ring 398 is mounted to the body 44 and fixed relative to the spindle 14, and the lip 394 engages the sealing ring 398, which rotates as the wheel hub body 16 rotates. The lip 394 and the sealing ring 398 are configured to push contaminants axially inwardly away from the interior of the air seal cartridge 40.

[0065] about Figure 7 , an air seal cartridge 400 is provided which is similar in many respects to the air seal cartridge 40 discussed above, the differences being highlighted herein. The air seal cartridge 400 includes a cartridge mounted to a spindle 403 (see Figure 8) and a rotatable pressurized air distributor 404 mounted to a wheel hub body 405. The non-rotatable pressurized air receiver 402 has a body 406 with an air inlet 408 to receive pressurized air. The rotatable pressurized air distributor 404 has a pressurized air outlet 407 with an outlet opening 410 to guide the pressurized air into a passage 409 of the wheel hub body 405. The rotatable pressurized air distributor 404 is press-fit into the wheel hub body 405, thereby inhibiting relative rotational movement of the rotatable pressurized air distributor 404 and the wheel hub body 405. The rotatable pressurized air distributor 404 also includes a groove 414 extending into the wheel hub body 405 (see Figure 8 ) in the wheel hub body 405. The engagement of the key 412 of the rotatable pressurized air distributor 404 with the groove 414 of the wheel hub body 405 further inhibits relative rotational movement of the rotatable pressurized air distributor 404 and the wheel hub body 405.

[0066] about Figure 8 , the air seal cartridge 400 includes an end face seal 420 having a disengaged configuration, wherein there is nominal contact between a rotatable sealing member 422 of the rotatable pressurized air distributor 404 and a sealing member 424 of the non-rotatable pressurized air receiver 402. For example, during periods of high vehicle speeds, the end face seal 420 is in a disengaged configuration to limit frictional engagement, forces, and high temperatures generated by contact between the rotatable sealing member 422 and the sealing member 424 due to rotation of the wheel hub 405. The end face seal 420 has an engaged configuration (see Fig. 9 ), wherein the sealing member 424 is tightly engaged with the rotatable sealing member 424 to form a transfer chamber 426 for conducting the pressurized air to the passage 409 of the wheel hub body 405.

[0067] refer to Figure 8, the air seal cartridge 400 includes a lubricant seal 430 for preventing lubricant from flowing out of the inner bearing assembly 432. The lubricant seal 430 includes a seal shell 434 mounted to the radial inner surface 436 of the wheel hub body 405 and rotatable therewith. The seal shell 434 has a seal body 438 made of a rigid material such as steel, aluminum or composite plastic, and a seal member 440 which may be made of a polymer material such as rubber or silicone. The lubricant seal 430 includes a lubricant seal sleeve 444 and a spindle mounting sleeve 446. The seal member 440 has a seal member 442 which engages with the lubricant seal sleeve 444 when the wheel hub body 405 rotates about the spindle 403. The spindle mounting seat 446 may be made of a polymer material to inhibit the flow of lubricant between the lubricant seal sleeve 444 and the spindle 403.

[0068] The non-rotatable pressurized air receiver 402 includes an annular body, such as a receiver spindle mount 450. The receiver spindle mount 450 includes a receiver spindle mount assembly 449, which includes a body 406, a base 452, and a sealing connector ring 454. The sealing connector ring 454 has a lip 456 that axially overlaps a flange 458 of the lubricant sealing sleeve 444 and inhibits axial separation of the receiver spindle mount 450 and the lubricant seal 430. The overlapping engagement of the lip 456 and the flange 458 increases the rigidity of the non-rotatable pressurized air receiver 402 on the spindle 403.

[0069] about Figure 8 , the rotatable pressurized air distributor 404 includes a sealing ring 470 and a sealing member 472, which engages with the radial inner surface 436 of the wheel hub body 405 around the passage 409. The sealing ring 470 and the sealing member 472 have an outlet opening 474 formed therein to the passage 409. The rotatable pressurized air distributor 404 also includes support rings 480A, 480B on which the rotatable sealing member 422 is mounted. In one embodiment, the rotatable seal 422 is fixed relative to the support rings 480A, 480B, and the support rings 480A, 480B are fixed relative to the sealing ring 470. In this way, the rotation of the wheel hub body 405 causes the sealing ring 470, the support rings 480A, 480B and the rotatable sealing member 422 to rotate. The rotatable pressurized air distributor 404 has a sealing member 490 that forms a seal around the outlet portion 492 of the rotatable sealing member 422. The sealing member 490 and support rings 480A, 480B define a passage 496 therebetween that directs pressurized air from the rotatable sealing member outlet portion 492 into the chamber 496 and then out through the opening 474 and into the passageway 409 .

[0070] The non-rotatable pressurized air receiver 402 includes a piston 500 having an opening 502 that can receive air via an opening 504 of the body 406. The non-rotatable pressurized air receiver 402 has a spring 510 that resiliently urges the piston 500 in a direction 512 so that there is slight contact between an outer end portion 514 of the piston 500 and an inner side 516 of the non-rotatable seal 424 even when pressurized air is not applied to the air inlet 408. In addition, when the end seal 420 is in the disengaged configuration, the gap between the non-rotatable seal member 424 and the rotatable seal 424 limits contact and associated wear due to friction and heat at high rotational speeds of the wheel hub body 405 (e.g., at highway vehicle speeds). Thus, when the face seal 420 is in the disengaged configuration, there is nominal contact between the piston 500 and the non-rotatable seal member 424 due to the action of the spring 510, and there is clearance between the non-rotatable seal member 424 and the rotatable seal 422. The nominal contact between the piston 500 and the seal member 424 ensures that when pressurized air is applied to the air inlet 408, the piston 500 immediately abuts against the seal 424 and minimizes leakage. The nominal contact between the piston 500 and the seal 424 also minimizes wear on the piston 500 and the non-rotatable seal 422.

[0071] The sealing member 424 has an opening 518 that allows air flow to travel through and into the passage 494. In this manner, when pressurized air is applied to the air inlet 408, the pressurized air creates a pressure differential across the piston 508, which increases the force acting on the piston 500 in the direction 512 and tightly clamps the sealing member 424 between the piston 500 and the rotatable seal 422, as shown in FIG. Fig. 9 shown.

[0072] In one embodiment, the non-rotatable pressurized air receiver 402 includes a thrust washer 503 located on a side of the rotatable seal member 422 opposite the non-rotatable seal 424. At least one of the thrust washer 503, the rotatable seal member 422, and the non-rotatable seal member 424 includes a wear-resistant material. Exemplary wear-resistant materials include wear-resistant plastics, such as polyamideimide (PAI) plastics and polybenzimidazole (PBI) plastics, and ceramic materials, such as coatings.

[0073] about Fig.10 , shows a non-rotatable pressurized air receiver 402, which includes a sealing member 424 and a thrust washer 503 with a passage 591 therebetween for receiving the rotatable sealing member 422 (see Fig. 9). The sealing member 424 has a sealing surface 593 that engages the ridges 544, 546 of the rotatable sealing member 422 when the piston 500 moves in the outboard direction 593 due to the application of pressurized air at the air inlet 408. The thrust washer 503 can be in clearance or nominal contact with the rotatable sealing member 422 when the face seal 420 is in the disengaged configuration. When the face seal 420 is moved to the engaged configuration by applying pressurized air at the air inlet 408, the thrust washer 503 provides a reaction force in a direction opposite to the direction 512 to support the rotatable sealing member 422 to prevent deflection.

[0074] The rotatable sealing member 422 has contact surface portions, such as the inside surfaces 540, 542 of the ridges 544, 546, which tightly engage the sealing member 424 to define the transfer chamber 426. In this manner, pressurized air applied to the air inlet 408 travels from the air inlet 408 along the flow path 550, through the opening 504 of the body 506, through the opening 502 of the piston 500, through the opening 518 of the sealing member 524, through the passage 494 of the rotatable sealing member 422, through the opening 474 in the sealing ring 470 and the sealing member 472, and into the passage 409 of the wheel hub body 405. In this manner, applying pressurized air to the air inlet 408 transitions the end face sealing member 420 from a disengaged configuration to a sealed configuration or an engaged configuration.

[0075] Similar to air seal cartridge 40, air seal cartridge 400 allows lubricant to escape from air seal cartridge 400 when lubricant seal 420 fails. Fig. 9 , support ring 480A has an opening 570, and seal ring 470 has an opening 572, which allows lubricant to travel inside from lubricant seal 420 into lubricant outlet passage 574 located at the periphery of gas seal sleeve 400 (see Figure 7 ). The lubricant enters the circumferential channel 576 through the lubricant outlet channel 574 and then enters the secondary channel 578. The lubricant can then flow from the secondary channel 578 in an inboard direction between the seal ring 470 and the wheel hub body 405 and eventually onto the outer surface of the wheel hub body 405 for visual inspection by a technician. The channels 576, 578 are offset from each other circumferentially to provide a tortuous path to prevent debris from entering.

[0076] The air seal cartridge 400 also allows pressurized air to escape from the air seal cartridge 400 when the face seal 420 fails, rather than pressurizing and potentially damaging the lubricant seal 430. More specifically, referring to Fig. 9, the base 452 has an outlet opening 580 that allows pressurized air to escape radially inward and travel along an air outlet passage 582 between the base 452 and the main shaft 403. The pressurized air exits the passage 582 in a direction 586 through an inner opening 584 between the body 406 and the main shaft 403.

[0077] refer to Fig.11 , the tire inflation system 600 includes a pressurized air rotary joint 602 for delivering pressurized air from a vehicle pressurized air supply 48 to a pressurized air distribution system 604, which may include one or more valves, conduits, and / or fittings to facilitate delivery of pressurized air from a passageway of a rotatable wheel hub to a tire 606. In one embodiment, the pressurized air rotary joint 602 includes a non-rotatable pressurized air receiver 608 and a rotatable pressurized air distributor 610. The pressurized air rotary joint 602 has an engaged configuration, in which the non-rotatable pressurized air receiver 608 and the rotatable pressurized air distributor 610 are operably coupled to allow pressurized air to flow therebetween, and a disengaged configuration, in which the pressurized air rotary joint 602 is unable to deliver pressurized air between the non-rotatable pressurized air receiver 608 and the rotatable pressurized air distributor 610. An example of a non-rotatable pressurized air receiver 608 is the non-rotatable pressurized air receiver 42 , 402 , while an example of a rotatable pressurized air distributor is the above-described rotatable pressurized air distributor 60 , 404 .

[0078] The system 600 includes a tire pressure sensor 620 configured to detect the internal air pressure of the tire 606, one or more sensors 622, and one or more wheel-end devices 624 operably connected to the electronic control unit 630. As some examples, the sensor 622 may include, for example, an ambient temperature sensor, a tire temperature sensor, a wheel hub temperature sensor, a stud tension sensor, an accelerometer, a gyroscope, a tire life sensor. As some examples, the wheel-end device 624 may include, for example, a valve (such as a valve for releasing pressurized air from the tire 606), an antenna, and / or an anti-lock brake sensor. The electronic control unit 630 has a communication circuit 632, which receives one or more parameters of the vehicle and the surrounding environment through the sensor 622 and / or the network 634. The network 634 may include a wired network, such as a vehicle-specific network, such as a CAN bus. Additionally or alternatively, as some examples, the network 634 may include a wireless network, such as a Wi-Fi network, a local wireless network, and / or a mesh network. As some examples, the network 634 may include the Internet and / or a wide-area wireless network (e.g., a cellular network).

[0079] The electronic control unit 630 includes a non-transitory computer-readable medium, such as a memory 635, for storing information about the control logic of the system 600, such as parameters, thresholds, limits, historical data, machine learning algorithms (e.g., neural networks), and other information. The memory 635 may include, for example, RAM, ROM, DRAM, and / or a hard drive. As some examples, the electronic control unit 630 includes a processor 636, such as a microprocessor, an application-specific integrated circuit, and / or a system on a chip. The processor 636 uses the information stored in the memory 635 to control the system 600 as described below.

[0080] The processor 636 can operate the communication circuit 632 to send command signals to the pump 52 and / or receive information about the pump 52, such as pump status, pump health, pump speed, and / or other parameters. The electronic control unit 630 can be dedicated to controlling the tire inflation system 600, or can participate in the operation of other systems of the vehicle. The electronic control unit 630 can communicate with the vehicle control unit 638 via the network 634. For example, the electronic control unit 630 can transmit tire pressure data to the vehicle control unit 638 to be provided to the user through the user interface 640 of the vehicle (e.g., a touch screen, a head-up display, and / or a stereo system). The user interface 640 can provide information about the system 600 to the user, such as tire condition warnings, leak detection, and system status.

[0081] In one embodiment, the electronic control unit 630 may also receive user input from the user interface 640 via the network 634, such as increasing the pressure of the tire 606. The electronic control unit 630 checks whether the vehicle speed is below an upper limit, such as three miles per hour. If the vehicle speed is below the upper limit, the electronic control unit 630 sends a command to the vehicle pressurized air supply 48 via the network 634 to open the valve of the vehicle pressurized air supply 48, provide pressurized air to the non-rotatable sealing portion 608, and inflate the tire 606. The electronic control unit 630 may also provide information about parameters of the tire inflation system 600, the condition of the tire inflation system 600, and historical information about the tire inflation system 600 to a remote computer 642 (e.g., a cloud-based computing system, a fleet manager's desktop computer, and / or a smartphone). As another example, the electronic control unit 630 may receive updates or other information from the remote computer 642, such as an updated machine learning algorithm based on historical data of a fleet associated with the target vehicle, so as to improve the operation of the electronic control unit 630 when collecting operational information from the fleet.

[0082] refer to Fig.12, a flow chart of a method 700 for tire pressure management is provided. The method 700 may be implemented by a processor 636 of an electronic control unit 630 based on a parameter 702 detected by a sensor 622. The processor 636 determines a condition 704 based on the parameter 702 and a response 714. For example, if the vehicle speed 706 is greater than zero miles per hour, the processor 636 may determine that the tire 606 is moving 708. Conversely, if the vehicle speed 706 is zero miles per hour, the processor 636 may determine that the tire 606 has stopped 710.

[0083] The condition 704 may encompass multiple conditions 704 of the vehicle, and the determination of the response 714 may be based on multiple parameters 702. For example, if the condition 704 determined by the processor 636 is that the tire 606 is moving 708 and the tire pressure 712 is below a threshold, the processor 636 may determine a response 716 to not apply pressurized air to the tire 606. Conversely, if the condition 704 indicates that the tire has stopped 710 and the tire pressure 712 is below a threshold, the processor 636 may determine a response 716 to pressurize the tire 718 by opening the valve 49 of the vehicle pressurized air supply 48 to release pressurized air from the reservoir 50 to the non-rotatable sealing portion 608. In one embodiment, the processor 636 monitors the tire pressure 712 via the tire pressure sensor 620 and closes the valve 49 when the tire pressure 712 exceeds the threshold or the vehicle begins to move and has a non-zero speed. The following table provides examples of parameters 702, conditions 704, and responses 714 that may be used with the method 700. Each row of the table indicates one or more parameters, a condition associated with the one or more parameters, and a corresponding response of the system 600 to the condition. Table 1: Parameters, conditions and responses of the method for controlling the tire inflation system

[0084] Method 800 can use a variety of parameters. For example, parameters can include wheel angular velocity, information from an anti-lock braking system, tire air temperature, tire material temperature, tire air flow rate, air supply flow rate (e.g., from valve 49), air supply volume (e.g., compressor and / or tank size), time, air quality, humidity, oil content of the air, tire information (e.g., material, type, and / or manufacturer), and vehicle configuration (e.g., whether tire 606 is a drive wheel, a steering wheel, a single tire, or a dual tire). Further parameters 702 that can be used include control states of whether other tires in the vehicle are inflated, user settings (e.g., tire pressure set points), and safety parameters (e.g., operating range extremes). The operating range extremes can include extremes of air pressure, vehicle speed, wheel angular velocity, and temperature. These parameters can be measured directly or inferred from other data. For example, vehicle speed can be inferred based on accelerometer measurements.

[0085] refer to Fig.13 , a method 800 for controlling tire pressure is provided. The electronic control unit 630 may operate the method 800 independently or in coordination with the vehicle control 638 or other vehicle control units of the vehicle. The electronic control unit 630 may autonomously perform the method 800 while the vehicle is running.

[0086] The method 800 includes the processor 636 determining 802 whether the tire under-inflation condition is satisfied. Operation 802 may include, for example, determining whether the tire pressure detected by the tire pressure sensor 620 is below a threshold pressure, a percentage of a target pressure, within an acceptable pressure range, or other methods. If the tire under-inflation condition is not satisfied in operation 802, the electronic control unit 630 checks again in operation 802 whether the tire under-inflation condition is satisfied.

[0087] If the under-inflation condition is met in operation 802, the electronic control unit 630 determines 804 whether the vehicle speed condition is met. The vehicle speed condition may be met when the vehicle speed is zero. As another approach, the vehicle speed condition may be met if the vehicle speed is less than a non-zero threshold value (e.g., five miles per hour). The processor 636 may determine the vehicle speed based on information from the vehicle control unit 638. As another example, the sensor 622 may include an accelerometer of a wheel hub that may provide information about the rotational speed of the wheel hub.

[0088] If the vehicle speed condition is not satisfied in operation 804, the electronic control unit 630 again performs operation 802. The electronic control unit 630 may wait for a predetermined period of time until performing operation 802, or may stand by for a vehicle speed indication from the vehicle control unit 638 indicating that the vehicle has stopped.

[0089] If the vehicle speed condition is met in operation 804, the electronic control unit 630 pressurizes the tire 606 for a time period 806. Pressurizing 806 may include the electronic control unit 630 opening the valve 49 to apply pressurized air to the non-rotatable pressurized air receiver 608 for a time period. The time period may be fixed, such as five seconds. The electronic control unit 630 closes the valve 49 at the end of the five seconds and repeats operations 802, 804, 806 until the pressure of the tire 606 is above the threshold pressure.

[0090] In one embodiment, the system 600 allows for dynamic inflation of the tire 606 while the vehicle is in motion. The time period can be short, such as three seconds, to limit the duration of engagement between the sealing portions of the pressurized air swivel 602. The system 600 can implement a delay period, such as two minutes, to allow the sealing portions to cool before pressurizing 806 the tire 606.

[0091] In another embodiment, the time period is variable. For example, the time period may be the time required to raise the tire pressure of tire 606 to above a threshold tire pressure. The time period may be shortened by the movement of the vehicle, and the electronic control unit 630 returns to operation 802. The processor 636 may operate a timer during pressurization 806, and if the time taken for the pressurization process is longer than a predetermined value (e.g., one minute), the timer times out. If the timer expires and the tire pressure does not reach the threshold, it may indicate that the tire 606 has a leak, and the electronic control unit 630 communicates with the vehicle control unit 638 to provide an alarm to the vehicle user through the user interface 640.

[0092] The tire inflation system 600 can control the inflation of multiple tires of a vehicle. For example, the tire inflation system 600 can have a first electronic control unit 630 that controls the inflation of tires of the drive wheels of the tractor, a second electronic control unit 630 that controls the inflation of tires of the steering wheels of the tractor, and a third electronic control unit 630 that controls the inflation of tires of a trailer connected to the tractor.

[0093] refer to Fig.14 and Fig.15 , a portion of an air seal cartridge 1100 is provided that is similar to the air seal cartridge 40 discussed above. The air seal cartridge 1100 has a disengaged configuration ( Fig.14 ) and joint configuration ( Fig.15) diaphragm seal 1101. Air seal cartridge 1100 includes a sealing sleeve 1102, a diaphragm 1104, diaphragm support rings 1106, 1108, and a body 1110 for mounting to a spindle. Diaphragm 1104 has a groove 1112 with a lip 1114 that engages with a flange 1116 of a diffuser ring 1118. Air seal cartridge 1100 has a diaphragm chamber 1120 to receive pressurized air. Pressurized air is applied to diaphragm chamber 1120, causing portions 1122, 1124 of diaphragm 1104 to bulge outwardly and causing ridge 1126 of diaphragm 1104 to engage with sealing sleeve 1102. Pressurized air is applied to diaphragm chamber 1120, causing diaphragm seal 1101 to be compressed from Fig.14 Move to the detached configuration Fig.15 Although Fig.14 and 15 Not shown, but the diaphragm 1104 and diffuser ring 1118 have aligned openings that allow pressurized air to flow from the diaphragm chamber 1120 into a passageway in the wheel hub to which the sealing sleeve 1102 is mounted.

[0094] refer to Fig.16 and Fig.17 , a portion of an air seal cartridge 1200 is provided, which is similar to the air seal cartridges 40, 1100 described above. The air seal cartridge 1200 has a disengaged configuration ( Fig.16 ) and joint configuration ( Fig.17 ) diaphragm seal 1201. Air seal cartridge 1200 includes sealing sleeve 1202, diaphragm 1204, diffuser ring 1206, diaphragm support rings 1208, 1210, diaphragm chamber 1212, and body 1214 for mounting to a spindle. Introducing pressurized air into diaphragm chamber 1212 displaces ridges 1218, 1220 to engage sealing sleeve 1214. Diaphragm 1204 has a necked portion 1222 and an enlarged portion 1224 to retain a protrusion of diffuser ring 1206, such as flange 1230.

[0095] One difference between air seal cartridge 1100 and air seal cartridge 1200 is that when air seal cartridge 1100 is in the disengaged configuration (see Fig.14 ), the diffuser ring 1118 of the air seal cartridge 1100 is spaced apart from the sealing sleeve 1102, and when the air seal cartridge 1200 is in the disengaged configuration (see Fig.16 ), the diffuser ring 1206 of the air seal sleeve 1200 contacts the sealing sleeve 1202. The diffuser ring 1206 contacting the sealing sleeve 1202 can be used as a secondary diffuser and a rigid seal.

[0096] about Fig.18, an air seal cartridge 1300 is provided, which is similar in many respects to the air seal cartridges discussed above. The air seal cartridge 1300 includes a non-rotatable pressurized air receiver 1302 and a rotatable pressurized air distributor 1304. The air seal cartridge 1300 has a lip seal 1306 that can be moved from a disengaged configuration to an engaged configuration to enable pressurized air to flow from an air inlet 1308 of the non-rotatable pressurized air receiver 1302 to an air outlet 1310 of the rotatable pressurized air distributor 1304. The lip seal 1306 includes sealing members 1312, 1314 of the non-rotatable pressurized air receiver 1302, which contact a sealing ring 1316 of the rotatable pressurized air distributor 1304. The sealing members 1312 , 1314 and the sealing ring 1316 form a compartment 1317 that receives pressurized air from the air inlet 1308 through a passage 1319 of the non-rotatable pressurized air receiver 1302 .

[0097] The sealing members 1312, 1314 have lip portions 1320, 1322 that lightly contact the sealing ring 1316 when the lip seal 1306 is in the disengaged configuration. Therefore, even at high vehicle speeds, the lip portions 1320, 1322 will contact the sealing ring 1316. The sealing members 1312, 1314 can be made of a polymer such as rubber or silicone. When pressurized air is provided to the air inlet 1308, the pressure in the compartment 1317 increases, which tightly presses the lip portions 1320, 1322 against the sealing ring 1316 and reconfigures the lip seal 1306 to the engaged configuration. The pressurized air can then flow from the compartment 1317 through the opening 1324 of the sealing ring 1316 and flow to the air outlet 1310 of the rotatable pressurized air distributor 1304.

[0098] refer to Fig.19 , an air seal cartridge 1400 is provided which is similar in many respects to the air seal cartridge 1300. The air seal cartridge 1400 includes a non-rotatable pressurized air receiver 1402, a rotatable pressurized air distributor 1404, and a lip seal 1406. The lip seal 1406 includes sealing members 1408, 1410 of the rotatable pressurized air distributor 1404. The rotatable air distributor 1404 has support rings 1420, 1422, 1424 for securing the seals 1408, 1410 to an outer ring 1425 of the rotatable pressurized air distributor 1404.

[0099] The sealing members 1408, 1410 have lip portions 1412, 1414 that lightly contact the sealing ring 1416 of the non-rotatable pressurized air receiver 1402 when the lip seal 1406 is in the disengaged configuration. The sealing members 1408, 1410 and the sealing ring 1416 form a compartment 1426 that communicates with an air inlet 1428 of the non-rotatable pressurized air receiver 1402 through an opening 1430 and a passage 1431 of the sealing ring 1416. When pressurized air is applied to the air inlet 1428, the air pressure within the compartment 1426 increases, forcing the lip portions 1412, 1414 of the sealing members 1408, 1410 more tightly against the sealing ring 1416 and reconfiguring the lip seal 1406 to the engaged configuration. Thus, pressurized air may flow from compartment 1426 , through opening 1440 in support ring 1422 , through opening 1442 in outer ring 1425 , to air outlet 1444 of air seal cartridge 1400 .

[0100] about Fig. 20 , an air seal cartridge 1500 is provided, which is similar in many respects to the air seal cartridges discussed above. The air seal cartridge 1500 includes a non-rotatable pressurized air receiver 1502, a rotatable pressurized air distributor 1504, and a lip seal 1506. The lip seal 1506 includes sealing members 1508, 1510 of the non-rotatable pressurized air receiver 1502. The sealing members 1508, 1510 can be made of a hard plastic material.

[0101] The sealing members 1508, 1510 have lip portions 1512, 1514 that lightly contact the annular body 1516 of the pressurized air distributor 1504 when the lip seal 1506 is in the disengaged configuration. The sealing members 1508, 1510 and the annular body 1516 form a compartment 1520 that receives pressurized air from an air inlet 1522 of the non-rotatable pressurized air receiver 1502 through a passage 1524 and a manifold 1526. Applying pressurized air to the air inlet 1522 increases the air pressure in the compartment 1520 and forces the lips 1512, 1514 against the annular body 1516 to reconfigure the lip seal 1506 into the engaged configuration. The pressurized air can exit the air seal cartridge 1500 at an outlet opening 1530 of the annular body 1516.

[0102] about Fig.21, an air seal cartridge 1600 is provided that is similar in many respects to the air seal cartridges discussed above. The air seal cartridge 1600 includes a non-rotatable pressurized air receiver 1602 (for being mounted to a main shaft 1604 of a vehicle) and a rotatable pressurized air distributor 1606 (which is mounted to a wheel hub 1608 that rotates about the main shaft 1604). The non-rotatable pressurized air receiver 1602 has a body 1610 having an air inlet 1612 and an air passage 1614 leading to an opening 1616. The non-rotatable pressurized air receiver 1602 includes a diaphragm 1630 having a mounting portion, such as a base flange portion 1632, 1634 sandwiched between a diaphragm support base 1624 and a channel portion 1636 of the sealing sleeve 1620 or a collar 1640 of the body 1610.

[0103] The pressurized air provided to the air inlet 1612 travels through the air passage 1614, through the opening 1616, through the gap 1617 between the body 1610 and the sealing sleeve 1620, and into the opening 1622 of the diaphragm support base 1624. The pressurized air can flow from the opening 1622 into the chamber 1650 between the diaphragm support base 1624 and the diaphragm 1630. The diaphragm 1630 includes an elastic diaphragm member 1652 and an air outlet (e.g., opening 1654). The opening 1654 allows the pressurized air to travel into the gap 1660 between the diaphragm 1630 and the rotatable sealing ring (e.g., sealing sleeve 1662). The pressure difference between the pressurized air in the cavity 1650 and the ambient air in the gap 1660 causes the contact portion 1664 of the diaphragm 1630 to bulge or protrude radially outward and engage with the sealing surface 1666 of the sealing sleeve 1662. The engagement between the contact portion 1664 and the sealing surface 1666 forms an airtight seal that allows pressurized air in the chamber 1650 to flow through the opening 1654, through the opening 1670 in the sealing sleeve 1662, through the outlet opening 1672 in the outer ring 1674 and the sleeve mount 1676, and into the inlet port 1678 of the passageway of the wheel hub 1608.

[0104] The non-rotatable pressurized air receiver 1602 includes a sleeve body 1680 having a sealing member 1682 that engages the outer diameter of the main shaft 1604. The sealing member 1682 has a dust lip seal 1704 to prevent dust or other debris from traveling in an outboard direction into the bearing 1700. The non-rotatable pressurized air receiver 1602 has an inboard O-ring 1712 to prevent dust and other debris from entering the lip seal 1704. The O-ring 1712 can also seal the air pressure within the air seal cartridge 1600.

[0105] The rotatable pressurized air distributor 1606 includes a seal housing 1686 mounted to the wheel hub 1608, which has a seal body 1690 and a seal element 1692. The seal element 1692 has a lubricant-to-air protective lip seal 1694, an air-to-lubricant protective lip seal 1696, and a main lip seal 1698. The lip seals 1694, 1696, 1698 engage the surface of the sleeve body 1680 to form a seal that prevents lubricant from flowing inward from the bearing 1700.

[0106] The sleeve body 1680 and the sealing element 1682 have a through hole 1702. When the diaphragm seal 1603 fails, the pressurized air can escape by deflecting the lubricant-air protection lip seal 1694, passing through the through hole 1702 and passing the lip seal 1704. In addition, the lip seal 1696 will be tightly pressed against the sleeve body 1680 by the escaping pressurized air and prevent the air from damaging the lip seal 1698.

[0107] If lubricant (eg, oil) leaks from lip seal 1698 and flows out through lip seal 1696 , lip seal 1694 will direct the lubricant through through hole 1702 and out past lip seal 1704 .

[0108] about Fig. 22 , the diaphragm seal 1750 provided is similar in many respects to the Fig.21 The diaphragm 1603 operates in a manner similar to that discussed below with respect to the diaphragm seal 1750. The diaphragm seal 1750 can operate over a wide range of operating temperatures, such as Fig. 22 70℉, Fig. 27 300°F, or Fig.32 -40℉ in.

[0109] Diaphragm seal 1750 includes diaphragm 1752, sealing sleeve 1754, and diaphragm support base 1757. Diaphragm 1752 includes elastic diaphragm member 1756, which has air outlet 1758 formed in contact portion 1760 of diaphragm member 1756. Diaphragm member 1756 also includes mounting portion, such as base flange portion 1762, 1764, which has spherical ring 1770, 1772 received in channel 1774, 1776 in sealing sleeve 1754.

[0110] Referring to the base flange portion 1762, the diaphragm support base 1757 has a lip portion 1780 having a flat surface 1782 and an inclined surface 1784 that engage with a radially inner surface portion of the base flange portion 1762. The inclined surface 1784 cooperates with a curved portion 1788 of the sealing sleeve 1754 to form a necked area 1786 that inhibits the ball ring 1770 from being pulled out from between the sealing sleeve 1754 and the diaphragm support base 1757. In addition, the ball ring 1770 can be compressed between the lip portion 1780, the inclined surface 1784, and the wall portion 1790 of the sealing sleeve 1754. In this way, the base flange portion 1762 is securely fixed to the sealing sleeve 1754 and the diaphragm support base 1757. The base flange portion 1764 is also secured between the sealing sleeve 1754 and the diaphragm support base 1757. In addition, the base flange portions 1762, 1764 form an airtight seal with the diaphragm support base 1757 such that pressurized air introduced into the chamber 1800 of the diaphragm seal 1750 via the opening 1802 of the diaphragm support base 1757 must exit the chamber 1800 via the air outlet 1758.

[0111] about Fig. 22 , the diaphragm member 1756 has an inner surface or interior surface 1804, and the pressurized air in the chamber 1800 presses against the inner surface 1804. The diaphragm member 1756 also includes an outer surface or exterior surface 1806, which is exposed to the ambient air pressure in the gap 1810 between the diaphragm member 1756 and the rotatable sealing ring (e.g., sealing sleeve 1812). When pressurized air is provided to the chamber 1800 through the opening 1802, the pressurized air acts on the interior surface 1804 and generates a force in a radially outward direction 1820 that is greater than the force associated with atmospheric pressure acting on the exterior surface 1806.

[0112] refer to Fig.23 , the air pressure differential acting on the inner surface 1804 and the outer surface 1806 of the diaphragm member 1756 causes the central thick portion 1836 of the diaphragm member 1756 to expand radially outward in the direction 1820, and drives one or more protrusions thereof (e.g., central bumps 1832, 1834) to contact the sealing surface 1830 of the sealing sleeve tube 1812. In one embodiment, the air outlet 1758 is an opening formed in the diaphragm member 1756, or alternatively, can be a nozzle embedded in the diaphragm member 1756 (e.g., see Fig.34 Middle nozzle 2046).

[0113] In one embodiment, the center bumps 1832, 1834 are annular ridges and cooperate with the annular sealing surface 1830 to define an annular space 1840 between the diaphragm member 1756 and the sealing surface 1830. The engagement between the center bumps 1832, 1834 and the sealing surface 1830 forms an initial seal that allows the air pressure in the chamber 1800 to increase and exert a greater force on the inner surface 1804 despite a decrease in the flow rate of the pressurized air through the air outlet 1758.

[0114] More specifically, once the center bumps 1832, 1834 are sealed with the sealing surface 1830, all the pressurized air leaving the air outlet 1758 is directed to the outlet opening 1850 of the sealing sleeve 1812, rather than some of the pressurized air escaping into the surrounding environment through the gap 1810. Therefore, since all the air is directed to the outlet opening 1850, the flow rate of the air is reduced. In addition, the pressurized air entering the outlet opening 1850 travels into the passage of the wheel hub supporting the sealing sleeve 1812 and enters the tire associated with the wheel hub. The tire may have an internal air pressure, so that the air flows into the tire and is subject to resistance, which further reduces the air flow rate through the outlet 1758. Although the air flow rate through the air outlet 1758 is reduced, the pressure difference between the ambient air pressure in the chamber 1800 and the gap 1810 will push the contact portion 1760 toward the sealing surface 1830. Additionally, the center bumps 1832, 1834 concentrate pressure acting on the inner surface 1804 of the diaphragm member 1756 and maintain the diaphragm member 1756 in sealing engagement with the sealing surface 1830 despite the reduced air flow rate through the air outlet 1758 of the diaphragm member 1756.

[0115] about Fig.23 As the thick portion 1836 bulges outward, the diaphragm member 1756 has wall portions 1860, 1861 that stretch while the base flange portions 1762, 1764 remain fixed between the sealing sleeve 1754 and the diaphragm support base 1757. When the gas pressure in the chamber 1800 is 10 pounds per square inch (psi), the diaphragm seal 1750 is as shown in FIG. Fig.23 as shown in .

[0116] about Fig.24 , the diaphragm member 1756 has thin-walled portions 1837, 1839 with intermediate projections 1880, 1882. Fig.24 The pressure in chamber 1800 changes from Fig.23The 10 psi increase in pressure causes the intermediate bumps 1880, 1882 to contact the sealing surface 1830. The intermediate bumps 1880, 1882 may be annular ridges similar to the center bumps 1832, 1834. Since the thin wall portions 1837, 1839 may flex relative to the center thick portion 1836, the intermediate bumps 1880, 1882 may move relative to the center bumps 1880, 1834. Once the center bumps 1832, 1834 have engaged the sealing surface 1830 and formed the annular space 1840, the intermediate bumps 1880, 1882 are driven against the sealing surface 1830 by the pressure differential between the chamber 1800 and the ambient air in the gap 1810.

[0117] Once the center nubs 1832, 1834 and the intermediate nubs 1880, 1882 engage the sealing surface 1830, the air flow rate of the atmospheric pressure air flowing into the gap 1810 may drop to zero due to the engagement between the nubs 1832, 1834, 1880, 1882 and the sealing surface 1830. There is no air flow into the ambient pressure air in the gap 1810, which reduces the pressure differential across the center thick portion 1836. However, the nubs 1832, 1834, 1880, 1882 act as force concentrators to enable the diaphragm member 1756 to continue to engage the sealing surface 1830 when the pressure differential across the center thick portion 1836 is reduced. The nubs 1832, 1834, 1880, 1882 maintain the diaphragm member 1756 in engagement with the sealing surface 1830 so that the pressure in the chamber 1800 can continue to increase and air can be directed into the outlet opening 1850.

[0118] about Fig.25 , chamber 1800 is at 120 psi and is fully pressurized. The contact portion 1760 of the diaphragm member 1756 includes external protrusions 1890, 1892 that contact the sealing surface 1830. Fig.25 As shown, all of the projections 1832, 1834, 1880, 1882, 1890, 1892 engage the sealing surface 1830. If the center projections 1832, 1834 fail, the middle projections 1880, 1882 operate to provide sealing contact with the sealing surface 1830. In addition, if the center projections 1832, 1834 and the middle projections 1880, 1882 fail, the outer projections 1890, 1892 can operate as a secondary backup. The radial walls 1860, 1861 of the diaphragm member 1756 are pressed against the radial wall portions 1891, 1893 of the sealing sleeve 1754. Radial wall portions 1891 , 1893 guide diaphragm member 1756 to expand radially outwardly such that when pressurized air is applied to cavity 1800 , contact portion 1760 of diaphragm member 1756 moves as an expansion ring that engages the inner diameter of sealing surface 1830 .

[0119] about Fig.26 , chamber 1800 is at 120 PSI. However, once the tire reaches a predetermined fill pressure, for example, the pressure within the tire and outlet opening 1850 is also 120 PSI. There is no longer a pressure differential across the air outlet 1758. The thick portion 1836 of the diaphragm member 1756 moves slightly radially inward away from the sealing surface 1830, and the annular space 1840 expands due to the balanced air pressure on both sides of the thick portion 1836. When the pressure differential across the air outlet 1758 drops to zero, the center bumps 1832, 1834 of the thick portion 1836 have a reduced pressure, forcing the center bumps 1832, 1834 against the sealing surface 1830. Fig.26 In the configuration of , the thin-walled portions 1837, 1839 still have a pressure differential across them because the pressure in the chamber 1800 is greater than the ambient air pressure in the gap 1810. The pressure differential across the thin-walled portions 1837, 1839 provides a pressure that continuously forces the middle protrusions 1880, 1882 against the sealing surface 1830. In this way, once the pressure differential across the air outlet 1758 approaches zero, the middle protrusions 1880, 1882 operate as the primary sealing member.

[0120] about Fig. 27 , diaphragm seal 1750 is shown at an elevated temperature of 300°F, and cavity 1800 is at ambient pressure to show how diaphragm member 1756 undergoes thermal expansion at elevated temperatures. The radial wall portions 1860, 1861 of diaphragm member 1756 are elongated, and base flange portions 1762, 1764 may widen so that their curved portions 1763, 1765 contact diaphragm support base 1757.

[0121] exist Fig. 27 In, because Fig. 27 The higher temperature of the diaphragm member 1756 in the contact portion 1760 is greater than the distance 1900 spaced apart. Fig. 22 The distance in 1902. Although Fig. 27 The diaphragm member 1756 undergoes thermal expansion, and the diaphragm seal 1750 still has a gap 1810 between the diaphragm member 1756 and the sealing surface 1830. In this way, the sealing surface 1830 can rotate around the stationary diaphragm member 1756 during movement of the associated vehicle without generating friction forces on the diaphragm member 1756.

[0122] Fig.28 It is shown that pressurized air has been applied to the diaphragm seal 1750 at a temperature of 300°F with the chamber 1800 at an internal pressure of 10 psi. Fig.28In the embodiment of the present invention, the center projections 1832, 1834 and the intermediate projections 1880, 1882 engage the sealing surface. Due to the thermal expansion of the diaphragm member 1756, the diaphragm seal 1750 is at 70°F (see Fig.23 ) when the internal pressure is 10 psi, the engagement of the middle protrusions 1880, 1882 occurs at a lower pressure. Fig.29 , the pressure ratio in chamber 1800 Fig.28 The pressure in is high, and all of the protrusions 1832 , 1834 , 1880 , 1882 , 1890 , 1892 are engaged with the sealing surface 1830 .

[0123] about Fig.30 , when the internal pressure of chamber 1800 reaches 120 psi, diaphragm seal 1750 is shown, but air continues to flow through air outlet 1758. Fig.31 In the embodiment, chamber 1800 is at 120 psi, but the pressure in the tire and the pressure at outlet opening 1850 are also 120 psi, so there is no pressure difference across air outlet 1758, and thick portion 1836 is Fig.30 The position in is moved slightly radially inward, which increases the radial height of the annular space 1840.

[0124] about Fig.32 , diaphragm seal 1750 is shown at a temperature of -40°F, and chamber 1800 is at ambient air pressure. Diaphragm member 1756 thermally contracts due to the low temperature such that radial wall portions 1860, 1861 may have shortened and contact portion 1760 has a generally concave shape. When pressurized air is directed into chamber 1800, projections 1832, 1834, 1880, 1882 will engage sealing surface 1830, but due to the rigidity of diaphragm member 1756, projections 1890, 1892 may not contact sealing surface 1830 even at maximum pressure. Despite the lack of contact between projections 1890, 1892 and sealing surface 1830, diaphragm member 1756 is still able to establish and maintain a seal with sealing surface 1830 through the pressure concentration provided by projections 1832, 1834, 1880, 1882.

[0125] about Fig.33, an air seal cartridge 2000 is provided, which is similar in many respects to the air seal cartridge discussed above. The air seal cartridge 2000 includes a non-rotatable pressurized air receiver 2002, a rotatable pressurized air distributor 2004, and a diaphragm seal 2006, which can be engaged to allow air received at an air inlet 2008 of the non-rotatable pressurized air receiver 2002 to flow into an inlet 2010 of a wheel hub 2012 to increase the air pressure in a tire associated with the wheel hub 2012. The non-rotatable pressurized air receiver 2002 includes a body 2020 and a mounting seat 2022 connected thereto. The body 2020 has a passage 2024, which is connected to a passage 2026 of the mounting seat 2024 through a pin 2028. The pin 2028 has O-rings 2030, 2032 to form an airtight connection between the body 2020 and the mounting seat 2022 and the through hole 2034. Pressurized air provided to the air inlet 2008 travels through the passages 2024 , 2034 , 2026 , passes underneath the diaphragm support base 2040 , through the opening 2044 of the diaphragm support base 2040 , into the chamber 2044 , and through the nozzle 2046 of the diaphragm 2048 of the diaphragm seal 2006 .

[0126] The diaphragm 2048 includes a diaphragm member 2050 that sealingly engages a sealing sleeve 2052 mounted to the wheel hub 2012 when the chamber 2044 is pressurized. The diaphragm member 2050 has base flange portions 2060, 2062 that are radially captured between the mounting seat 2022, the outboard diaphragm support ring 2070, and the inboard diaphragm support ring 2072. Fig.34 , the nozzle 2046 can be made of a metal or plastic material and fixed to the diaphragm member 2050, for example, molded into the diaphragm member 2050.

[0127] Back to Fig.33 , the outboard diaphragm support ring 2070 has a radially outer running surface 2080, and the rotatable pressurized air distributor 2004 includes seals 2082, 2084 that engage the running surface 2080 to restrict the flow of lubricant and debris. The air seal cartridge 2000 also includes a seal shell 2090 mounted to the wheel hub 2012, the seal shell 2090 having a lip seal 2092 that engages a mounting sleeve 2094 connected to the mounting seat 2022 and fixed to the main shaft 2096. The air seal cartridge 2000 and the main shaft 2096 have a passage 2100 therebetween to allow lubricant to escape in the event of a lip seal 2092 failure.

[0128] The use of singular terms, such as "a", "an", is intended to cover the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. For example, reference to a sensor that detects a parameter is intended to cover one or more sensors that detect one or more parameters. The terms "comprising", "having", "including", and "containing" are to be interpreted as open-ended terms. The phrase "at least one" as used herein is to be interpreted in a disjunctive sense. For example, the phrase "at least one of A and B" is intended to cover A, B, or both A and B.

[0129] While particular embodiments of the present invention have been illustrated and described, it will be understood that numerous changes and modifications will occur to those skilled in the art and the present invention is intended to cover all such changes and modifications which fall within the scope of the appended claims.

Claims

1. A rotary joint for a wheel end system, the wheel end system comprising a wheel hub having a passage, the rotary joint comprising: a pressurized air receiver configured to be mounted to a vehicle spindle; an air inlet of the pressurized air receiver; a pressurized air distributor rotatable about an axis relative to the pressurized air receiver, the pressurized air distributor being configured to be mounted to and rotate with the wheel hub; an air outlet of the pressurized air distributor for directing pressurized air toward a passage of the wheel hub; seals for the pressurized air receiver and the pressurized air distributor axially spaced from an air inlet of the pressurized air receiver such that the seals and the air inlet are offset from one another along the vehicle spindle to which the pressurized air receiver is mounted and to which the pressurized air distributor is mounted to the wheel hub; as well as The seal is transitionable from a disengaged configuration to an engaged configuration to allow pressurized air received at the air inlet of the pressurized air receiver to flow to the air outlet of the pressurized air distributor.

2. The rotary joint of claim 1 , wherein the pressurized air receiver includes a pressurized air receiver passage connecting the seal and the air inlet, the pressurized air receiver passage being oriented to extend along the vehicle spindle, wherein the pressurized air receiver is mounted to the vehicle spindle.

3. The rotary joint of claim 1, wherein the pressurized air receiver comprises an annular body including the air inlet, the annular body having a central opening sized to receive the vehicle spindle.

4. The rotary joint of claim 1 , wherein the pressurized air distributor includes a sealing member having an opening defining at least a portion of an air outlet of the pressurized air distributor, the sealing member being configured to engage a radially inner surface of the wheel hub.

5. The rotary joint of claim 4, wherein the pressurized air distributor comprises a rotatable sealing ring radially inwardly of the sealing member; and in, The seal includes a non-rotatable sealing member of the pressurized air receiver, the non-rotatable sealing member tightly engaging the rotatable sealing ring with the seal in the engaged configuration and loosely engaging the rotatable sealing ring with the seal in the disengaged configuration.

6. The rotary joint according to claim 1, further comprising a bearing seal assembly comprising: a non-rotatable sleeve connected to the pressurized air receiver and configured to be mounted to the vehicle spindle; a rotatable sleeve connected to the pressurized air distributor and configured to be mounted to the wheel hub, the rotatable sleeve being rotatable relative to the non-rotatable sleeve when the pressurized air distributor rotates relative to the pressurized air receiver; as well as A sealing member of one of the non-rotatable sleeve and the rotatable sleeve engages a surface of the other of the non-rotatable sleeve and the rotatable sleeve when the rotatable sleeve rotates relative to the non-rotatable sleeve.

7. The rotary joint of claim 1, wherein the seal is configured to transition from the disengaged configuration to the engaged configuration when the air inlet receives pressurized air.

8. The rotary joint of claim 1, wherein the pressurized air distributor comprises a sealing ring; and in, The pressurized air receiver includes a seal that tightly engages the sealing ring with the seal in the engaged configuration and loosely engages the sealing ring with the seal in the disengaged configuration.

9. The rotary joint of claim 1, wherein the seal comprises a diaphragm seal.

10. The rotary joint of claim 1, wherein the seal comprises a face seal.

11. The swivel joint of claim 1 , wherein the seal comprises a lip seal.

12. The rotary joint of claim 1, wherein the pressurized air receiver comprises an annular body having a radially inner passage configured to direct lubricant and / or pressurized air along a radially outer surface of the main shaft upon failure of the seal.

13. The rotary joint of claim 1, wherein the pressurized air distributor comprises an annular body having a radially outer passage configured to direct lubricant along a radially inner surface of the wheel hub.

14. The swivel joint of claim 1 in combination with the wheel hub, the wheel hub comprising a unitary, unitary wheel hub body having a central opening and an annular inner surface extending about the central opening; in, The pressurized air distributor includes a radially outer portion configured to engage the annular inner surface of the wheel hub body.

15. The rotary joint of claim 1, wherein the pressurized air receiver is configured to direct pressurized air received at the air inlet along a path outside of and along the main shaft between the wheel hub and the main shaft.

16. A rotary joint according to claim 1, wherein the seal includes sealing portions of the pressurized air receiver and the pressurized air distributor; in the disengaged configuration, the sealing portions are spaced apart from the seal, and in the engaged configuration, the sealing portions are in contact with each other.

17. A rotary joint according to claim 1, wherein the seal includes sealing portions of the pressurized air receiver and the pressurized air distributor; in the disengaged configuration, the sealing portions are in contact with the seal, and in the engaged configuration, the sealing portions are in more secure contact with the seal than in the disengaged configuration.

18. A wheel hub, comprising: a wheel hub body including a wheel mounting portion; an inner bearing and an outer bearing for rotatably mounting the wheel hub body to a vehicle spindle, a pressurized air passageway associated with the wheel hub body and rotatable with the wheel hub body about the vehicle spindle; a swivel joint located inboard of the inboard bearing and including an air inlet for receiving pressurized air and an air outlet for directing pressurized air to the pressurized air passage, the air outlet being rotatable with the wheel hub body about the vehicle spindle; as well as A seal of the rotary joint is operable to pneumatically connect and disconnect the air inlet and the air outlet of the rotary joint.

19. The wheel hub of claim 18, wherein the seal pneumatically connects the air inlet and the air outlet when pressurized air is applied to the air inlet of the rotary joint, and pneumatically disconnects the air inlet and the air outlet when pressurized air is not applied to the air inlet of the rotary joint.

20. The wheel hub of claim 18, wherein the pressurized air passageway comprises a pressurized air inlet port located inboard of the inboard bearing and a pressurized air outlet port located outboard of the inboard bearing.

21. The wheel hub of claim 18, wherein the mounting portion of the wheel hub comprises a mounting flange; in, The pressurized air passage includes a pressurized air inlet port located on an inner side of the mounting flange and a pressurized air outlet port located on an outer side of the mounting flange.

22. The wheel hub of claim 18, wherein the air inlet of the swivel joint is located on the inner side of the hub wheel.

23. The wheel hub of claim 18, wherein the swivel joint comprises an annular body having a central opening to receive the vehicle spindle, the annular body comprising the air inlet.

24. The wheel hub of claim 18, further comprising a lubricant seal assembly intermediate said inboard bearing and said swivel joint.

25. The wheel hub of claim 18, wherein the rotary joint comprises a non-rotatable body configured to be mounted to the spindle; a mounting ring secured to the non-rotatable body intermediate the non-rotatable body and the inboard bearing; and A seal housing is mounted to the wheel hub and has a seal member that engages the mounting ring to prevent lubricant from traveling from the inboard bearing in an inboard direction toward the swivel joint.

26. The wheel hub of claim 18, wherein the rotary joint comprises an annular body having a radial inner passage facing the main shaft to allow lubricant and / or air to flow therethrough and along the main shaft in the event of failure of the seal.

27. The wheel hub of claim 18, further comprising a lubricant seal intermediate said inboard bearing and said swivel joint; and in, The swivel joint therefore comprises an annular member mounted to the wheel hub, the annular member having a radially outer passage facing the wheel hub body and allowing lubricant to flow through the radially outer passage in the event of a lubricant seal failure.

28. The wheel hub of claim 18, wherein the rotary joint comprises a non-rotatable pressurized air receiver mounting ring having a central opening to receive the spindle; and a rotatable pressurized air distributor mounting ring extending about the non-rotatable pressurized air receiver mounting ring; and wherein the seal comprises a rotatable sealing portion supported by the rotatable pressurized air distributor mounting ring and a non-rotatable sealing portion supported by the non-rotatable pressurized receiver mounting ring; and wherein the non-rotatable sealing portion is tightly pressed against the rotatable sealing portion in response to the air inlet of the rotary joint receiving pressurized air.

29. The wheel hub of claim 18, wherein the rotary joint comprises an annular non-rotatable pressurized air receiver having a central opening to receive the vehicle spindle; and an annular rotatable pressurized air distributor; in, the rotatable pressurized air distributor having a radially outer surface frictionally engaged with a radially inner surface of the wheel hub body; as well as A spindle nut is configured to couple to the vehicle spindle and retain the non-rotatable pressurized air receiver on the spindle.

30. The wheel hub of claim 18, wherein the wheel hub body includes a central opening for receiving the vehicle spindle, an inner surface defining at least a portion of the central opening, and an outer surface opposite the inner surface; and in, The pressurized air passage extends from the inner surface to the outer surface.

31. The wheel hub of claim 18, wherein the seal comprises: Diaphragm seals; End seals; or Lip seals.

32. The wheel hub of claim 18, wherein the seal includes sealing portions configured to move together when pressurized air is applied to the air inlet of the rotary joint and to move apart when pressurized air is not applied to the air inlet.

33. The wheel hub of claim 18, wherein said wheel hub body has a unitary, unitary structure.

34. The wheel hub according to claim 18, wherein the seal includes a sealing portion; when the sealing portions are spaced apart, the air inlet and the air outlet are pneumatically disconnected; when the sealing portions are in contact with each other, the air inlet and the air outlet are pneumatically connected.

35. The wheel hub according to claim 18, wherein the seal includes a sealing portion; when the sealing portions contact each other, the air inlet and the air outlet are pneumatically disconnected; when the sealing portions contact each other more tightly than when the air inlet and the air outlet are pneumatically disconnected, the air inlet and the air outlet are pneumatically connected.

36. A diaphragm seal comprising: annular diaphragm; a groove of the diaphragm for receiving pressurized air; an air outlet of the diaphragm to allow the pressurized air to flow out of the diaphragm from the groove of the diaphragm; a contact portion of the diaphragm configured to move toward the sealing surface in a first radial direction in response to the groove receiving the pressurized air, the contact portion configured to move away from the sealing surface in an opposite second radial direction when the pressurized air is no longer provided to the groove of the diaphragm; as well as The protrusion of the contact portion of the diaphragm is configured to engage with the sealing surface when the contact portion moves in the first radial direction.

37. The diaphragm seal of claim 36, wherein the protrusion comprises a pair of annular protrusions located on opposite sides of the air outlet.

38. The diaphragm seal of claim 36, wherein the protrusion comprises: a first pair of annular protrusions located on opposite sides of the air outlet; as well as A second pair of annular protrusions are located on opposite sides of the air outlet, and the first pair of annular protrusions and the air outlet are located in the middle of the second pair of annular protrusions along the contact portion.

39. The diaphragm seal of claim 36, wherein the diaphragm has a central axis, wherein the protrusion comprises: a pair of central annular projections having an air outlet therebetween along the central axis; a pair of intermediate annular protrusions spaced apart from the central annular protrusion along the central axis, the central annular protrusion being located intermediate the intermediate annular protrusion along the central axis; and a pair of outer annular projections spaced apart from the middle annular projection; Wherein, the middle annular protrusion, the central annular protrusion and the air outlet are located between the outer annular protrusions along the central axis.

40. The diaphragm seal of claim 36, wherein the protrusion comprises a first protrusion adjacent to the air outlet, and a second protrusion farther from the air outlet than the first protrusion; in, the contact portion of the diaphragm being configured such that the first protrusion contacts the sealing surface and the second protrusion is spaced apart from the sealing surface in response to pressurized air having a first pressure in the groove of the diaphragm; as well as Wherein the contact portion of the diaphragm is configured to cause the first protrusion and the second protrusion to contact the sealing surface in response to pressurized air having a second pressure within the groove, wherein the second pressure is greater than the first pressure.

41. The diaphragm seal of claim 36, wherein the diaphragm comprises a resilient diaphragm member and a nozzle movable with the diaphragm member, the nozzle comprising the air outlet.

42. The diaphragm seal of claim 36, wherein the contact portion has an outer surface portion including a protrusion and an inner surface portion opposite the outer surface; in, The contact portion includes a first thin-walled portion and a second thin-walled portion, each of the first thin-walled portion and the second thin-walled portion having a thin wall thickness between the inner surface portion and the outer surface portion; wherein the contact portion comprises a thick-walled portion connecting the first thin-walled portion and the second thin-walled portion, the thick-walled portion having a thick-wall thickness between the inner surface portion and the outer surface portion, the thick-wall thickness being greater than the thin-wall thickness; and Wherein, the thick-walled portion comprises an air outlet of the diaphragm.

43. The membrane of claim 36, wherein the membrane comprises: a diffuser ring including said air outlet; as well as a pair of diaphragm members connected to the diffusion ring; The contact portion includes a contact portion of the diaphragm member that is movable relative to the diffusion ring.

44. The diaphragm of claim 36, further comprising a diaphragm support base having an air inlet in communication with the recess of the diaphragm to allow pressurized air to pass through the air inlet of the diaphragm support base and into the recess; and in, The diaphragm includes a mounting portion fixed relative to the diaphragm support base.

45. The diaphragm of claim 36, further comprising a diaphragm sleeve having a channel and a diaphragm support base having a lip portion located in the channel; and in, The diaphragm includes a mounting portion secured in a passage between the diaphragm sleeve and the diaphragm support base.

46. ​​The diaphragm of claim 36, wherein the groove includes an inlet opening, and the diaphragm includes a mounting portion extending along both sides of the inlet opening, the inlet opening being located radially inward of the contact portion of the diaphragm.

47. The diaphragm of claim 46, wherein the diaphragm includes a radial wall portion connecting the contact portion and the mounting portion.

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