Patent Application
20240010179
The present application relates to vehicle air brake charging systems, and is particularly directed to an air dryer apparatus for a vehicle air brake charging system, such as a truck air brake charging system.
A truck air brake charging system includes a vehicle air compressor which builds air pressure for an air braking system. The compressor is typically lubricated by an engine oil supply. A governor controls system air pressure between a preset maximum and minimum pressure level by monitoring the air pressure in a supply reservoir. When the supply reservoir air pressure becomes greater than that of a preset “cut-out” setting of the governor, the governor controls the compressor to stop the compressor from building air and also causes an air dryer downstream from the compressor to go into a purge cycle. As the supply reservoir air pressure drops to a preset “cut-in” setting of the governor, the governor returns the compressor back to building air and the air dryer to the charge cycle.
The air dryer is an in-line filtration system that collects and removes both water vapor and oil droplets from the compressor discharge air after it leaves the compressor. This results in cleaner, drier air being supplied to the air braking system, increases the life of the components of the brake assembly, and aids in the prevention of air line and component freeze ups in winter weather. The air dryer typically uses a replaceable “spin on” cartridge containing a desiccant material and an oil separator. Most of the oil droplets are removed by the oil separator as the air passes through the inlet tube into the air dryer. The air then moves through the desiccant material which adsorbs most of the water vapor.
When the air pressure in the supply reservoir reaches the preset cut-out setting of the governor, the governor makes the compressor stop building air and allows the air dryer's “purge cycle” to begin. During the purge cycle, the desiccant material is regenerated (i.e., its ability to remove water is renewed) by a reversal of the saturation process. A small amount of dry air passes back through the desiccant material and the water that has been collected, as well as any oil droplets collected by the oil separator, are purged out through a purge valve to atmosphere.
Some air dryers include a fully integrated governor. In these air dryers, the air dryer includes an air dryer housing having a bore in which a governor assembly is disposed. The governor assembly includes a metallic sleeve in which a piston slides between different positions to provide the preset cut-out (130 psi) and the preset cut-in settings of the governor. The metallic sleeve is located in the bore to maintain the piston and other internal components in place relative to the air dryer housing.
During operation of the vehicle air brake charging system, the governor cycles many times between the preset cut-out setting and the preset cut-in setting. Due to normal wear and tear of components, the governor assembly needs to be replaced from time to time. Accordingly, those skilled in the art continue with research and development efforts in the field of air dryers and governors for vehicle air brake charging systems.
In accordance with one embodiment, an air dryer apparatus is provided for a vehicle air brake charging system. The air dryer apparatus comprises an air dryer governor assembly. The air dryer governor assembly includes a plastic sleeve having an external sleeve surface and an internal sleeve surface that defines a piston bore. The air dryer governor assembly also includes a piston disposed in the piston bore and slidable along the internal sleeve surface between a preset cut-out setting and a preset cut-in setting of the air dryer governor assembly. The air dryer governor assembly further includes one or more ribs disposed on the external sleeve surface to prevent deformation of the plastic sleeve when the piston slides along the internal sleeve surface between the preset cut-out and cut-in settings.
In accordance with another embodiment, an air dryer apparatus is provided for a vehicle air brake charging system. The air dryer apparatus comprises an air dryer having a housing surface that defines a governor bore. The air dryer apparatus further comprises an air dryer governor assembly disposed in the governor bore. The air dryer governor assembly includes a governor sleeve having an internal sleeve surface that defines a piston bore and an external sleeve surface that faces the housing surface of the air dryer. The air dryer governor assembly also includes a governor piston disposed in the piston bore and slidable along the internal sleeve surface between a preset cut-out setting and a preset cut-in setting of the air dryer governor assembly. The air dryer governor assembly further includes one or more ribs disposed on the external sleeve surface and abutting against the housing surface of the air dryer to prevent deformation of the governor sleeve when the governor piston slides along the internal sleeve surface between the preset cut-out and cut-in settings.
In accordance with yet another embodiment, an air dryer apparatus is provided for a vehicle air brake charging system. The air dryer apparatus comprises a substantially cylinder-shaped governor sleeve having an external sleeve surface and an internal sleeve surface that defines a piston bore. The air dryer apparatus also comprises a governor piston disposed in the piston bore and slidable along the internal sleeve surface between a preset cut-out setting and a preset cut-in setting. The air dryer apparatus further comprises stiffening means disposed on the external sleeve surface and for, providing stiffness of the sleeve to prevent deformation of the governor sleeve when the governor piston slides along the internal sleeve surface between the preset cut-out and cut-in settings.
In accordance with still another embodiment, an apparatus is provided for a vehicle system. The apparatus comprises a substantially cylinder-shaped sleeve having an external sleeve surface and an internal sleeve surface that defines a piston bore. The apparatus also comprises a piston disposed in the piston bore and slidable along the internal sleeve surface between opposite end positions. The apparatus further comprises one or more ribs disposed on the external sleeve surface and for, preventing deformation of the sleeve when the piston slides along the internal sleeve surface between the opposite positions. The sleeve and the one or more ribs comprise a nylon material, and each of the one or more ribs is reinforced with glass fibers that are oriented in a direction substantially parallel to a longitudinal central axis of the piston.
The present application is directed to an apparatus for a vehicle system. The specific construction of the apparatus and the industry in which the apparatus is implemented may vary. It is to be understood that the disclosure below provides a number of embodiments or examples for implementing different features of various embodiments. Specific examples of components and arrangements are described to simplify the present disclosure. These are merely examples and are not intended to be limiting. By way of example, an air dryer apparatus for a vehicle air brake charging system, such as a truck air brake charging system, is described herein.
Referring to
Referring to
The air dryer governor assembly 120 also includes a governor piston 130 disposed in the piston bore 128. The governor piston 130 is slidable along the internal sleeve surface 126 between a preset cut-out setting and a preset cut-in setting of the air dryer governor assembly 120. The governor piston 130 has a longitudinal central axis 132 along which the governor piston 130 slides between the preset cut-out setting and the preset cut-in setting.
Referring to
Outer diameter of the plastic governor sleeve 122 in the vicinity of the end portion 124a is in a range between about 1.44 in (36.576 mm) and about 1.46 in (37.084 mm). Outer diameter of the plastic governor sleeve 122 in the vicinity of the opposite end portion 124c is in a range between about 1.46 in (37.084 mm) and about 1.54 in (39.116 mm). Axial length of the plastic governor sleeve 122 is in a range between about 3.79 in (90.26 mm) and about 3.81 in (96.77 mm).
Three sets of ribs 150, 160, 170 are axially spaced apart from each other along the longitudinal central axis 132 of the governor piston 130. Axial distance between the set of ribs 150 and the set of ribs 160 is in a range between about 1.54 in (39.116 mm) and about 1.58 in (40.132 mm). Axial distance between the set of ribs 160 and the set of ribs 170 is in a range between about 0.17 in (4.318 mm) and about 0.21 in (5.334 mm). In a preferred embodiment, the axial distance between the set of ribs 150 and the set of ribs 160 is about 1.56 in (39.624 mm), and the axial distance between the set of ribs 160 and the set of ribs 170 is about 0.19 in (4.826 mm).
Although three sets of ribs 150, 160, 170 are shown in
Referring to
Circumferential length of each of the ribs 151, 152, 153 is in a range between about 0.500 in (12.70 mm) and about 0.552 in (14.02 mm). Circumferential distance between an end of one of the ribs 151, 152, 153 and an end of another one of the ribs 151, 152, 153 is in a range between about 0.96 in (24.384 mm) and about 1.06 in (26.924 mm). In a preferred embodiment, the circumferential length of the rib 151 is about 1.508 in (38.303 mm), the circumferential length of the rib 152 is about 1.508 in (38.303 mm), the circumferential length of the rib 153 is about 1.508 in (38.303 mm), the circumferential distance between one end of rib 151 and one end of rib 152 is about 1.012 in (25.705 mm), the circumferential distance between one end of rib 152 and one end of rib 153 is about 1.012 in (25.705 mm), and the circumferential distance between one end of rib 151 and one end of rib 153 is about 1.012 in (25.705 mm).
Although three separate ribs 151, 152, 153 are shown in
Referring to
Referring to
The three separate ribs 151, 152, 153 of the set of ribs 150 are larger than the three separate ribs of each of the other two sets of ribs 160, 170. As best shown in
The three separate ribs of each set of the three sets of ribs 150, 160, 170 are circumferentially spaced apart from each other by a distance to provide sufficient space between ends of adjacent ribs for air flow therethrough during operation of the air dryer governor assembly 120. The locations of the three sets of ribs 150, 160, 170 relative to each other on the external sleeve surface 124 as well as the distances between adjacent ribs in each set of ribs provides a maximum strength of the plastic governor sleeve 122 using a minimum number of ribs while supporting sufficient air flow through the air dryer governor assembly 120.
The plastic governor sleeve 122 preferably comprises a nylon material that is reinforced with glass fibers. As an example, the nylon material of the plastic governor sleeve 122 may comprise Nylon 6/6 with glass fiber of 43%. Other nylon materials with other percentages of glass fiber are possible. Glass fibers of each rib are oriented in a direction substantially parallel to the longitudinal central axis 132 of the governor piston 130. The body portion 123 of the plastic governor sleeve 122 is reinforced with glass fibers oriented in one or more directions that are different from the direction in which glass fibers of each rib are oriented.
Referring to
In accordance with an aspect of the present disclosure, the geometry of the ribs of the three sets of ribs 150, 160, 170 reinforces the plastic governor sleeve 122 to withstand loads from pressure, humidity, air flow, and high temperatures without experiencing performance issues. Notably, the ribs of the three sets of ribs 150, 160, 170 cooperate together to maintain the geometry of the plastic governor sleeve 122 with minimal deformation when the governor piston 130 slides along the internal sleeve surface 126 between the preset cut-out and cut-in settings. This prevents a gap from forming between the plastic governor sleeve 122 and the governor piston 130. By preventing a gap from being formed, air leakage between the plastic governor sleeve 122 and the governor piston 130 is avoided.
A number of advantages are provided by the disclosed plastic sleeve 122 of
Another advantage is the comparable structural rigidity of the plastic sleeve 122 to a metallic sleeve. The comparable structural rigidity of the plastic sleeve 122 is due to its anisotropic properties (i.e., its different mechanical behavior in the x, y, and z directions). Moreover, the shape, dimensions, locations, and pattern (i.e., geometry) of the ribs on the external sleeve surface 124, as well as the orientation of glass fibers in the ribs, augment the structural rigidity of the plastic sleeve 122.
Although the above description describes the plastic governor sleeve 122 embodied in an air dryer apparatus 100 comprising the air dryer governor assembly 120, it is conceivable that the plastic governor sleeve 122 be embodied in a different apparatus. For example, as shown in
While the present invention has been illustrated by the description of example processes and system components, and while the various processes and components have been described in detail, applicant does not intend to restrict or in any way limit the scope of the appended claims to such detail. Additional modifications will also readily appear to those skilled in the art. The invention in its broadest aspects is therefore not limited to the specific details, implementations, or illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicant's general inventive concept.
