Patent Application
20100117318
Embodiments of the present invention relate generally to vehicle suspension and, more particularly, to an integrated air spring and damper suspension system and method for a trailer.
Vehicle suspension systems are often limited in the amount of weight they can suspend as well as the rebound and jounce travel distance they can support. In large vehicle applications, reliability due to component fatigue can be a significant consideration. Generally, reliability decreases as the number of components of the suspension system increases. Reliability can also be adversely affected by mechanical stresses such as moments and torques applied to various points or components of the suspension system. Furthermore, the weight and physical displacement of the suspension system components themselves can also affect vehicle operational parameters. In addition, mechanical clearance and/or interference for the suspension system in rebound and jounce travel can also affect vehicle operation and maneuverability.
Embodiments of the present invention address these concerns and others associated with trailer suspension systems. Many conventional independent variable height suspension systems have a separately attached air spring and shock absorber (damper) configuration for each wheel of a trailer, which requires individual mounting provisions and mounting space on suspension components, such as control arms, and the trailer frame. Such conventional suspensions and mounting configurations reduce the mobility and the suspension performance of the trailer because the suspension articulation in such conventional systems is limited. Furthermore, such conventional systems provide limited ground clearance and roll stability. Embodiments of the present invention can significantly reduce complexity and parts count, while improving suspension articulation and enhancing vehicle mobility and vehicle dynamic performance. Embodiments may also provide controllable and variable ride height for each of a plurality of trailer wheels.
Embodiments relate generally to trailer suspension systems and methods with reduced number of parts used and high flexibility for the independent variable ride height suspension system for a trailer. Conventional fully independent double wishbone suspension systems are often provided with an air spring and a shock absorber separately connected to the control arms and to the frame. In contrast, embodiments can comprise a variable ride height fully independent double wishbone trailer suspension system that includes an integrated air spring damper assembly. As such, embodiments can reduce the physical dimension and weight of the trailer suspension components and also reduce the number of parts required in the suspension assembly.
An integrated air spring and damper assembly in accordance with various embodiments can be mechanically simple and compact in order to provide reduced suspension weight, because fewer parts are needed in the assembled system as compared to conventional suspensions, and to provide additional clearance between suspension components to allow increased suspension articulation.
With respect to
With respect to
For example, with respect to
In various embodiments according to
As shown in
A ride height link 120 can be rotatably attached at one end to an upper wishbone control arm 107 and at another end to a ride height sensor 121 mounted on the frame of the vehicle. In various embodiments, the ride height link 120 can be attached to the upper control arm 107. The ride height sensor 121 can be designed to output an electrical signal which varies based on a corresponding varying force imparted by the ride height link 120 to a sensor armature, as shown in
In various embodiments, a knuckle 106 can be rotatably attached at a lower end to the lower control arm assembly 103. The knuckle 106 can also be rotatably attached at an upper end to an upper control arm 107. In various embodiments, the upper control arm 107 can be V-shaped; however, other shapes are possible. In various embodiments, the lower control arm 103 and the upper control arm 107 can be formed of a high-strength, lightweight metal such as, for example, titanium. A wheel hub 108 for mounting of a wheel can be attached to the knuckle 106. In the embodiments shown in both
With respect to
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The two spherical bearings 105 can each be enclosed by a pillow block 110. The spherical bearings 105 can surround or be annularly disposed about a transversely extending pin 112 provided at one end of each leg 111. The pins 112 can be constructed to be received by a boss of the pillow block 110. Bolts and washers can be used to secure the pins 112 and spherical bearings 105 in the pillow blocks 110. However, other attachment means are possible such as, without limitation, rivets, screws, and the like. In at least one embodiment, the pillow blocks 110 are formed from cast iron.
According to various embodiments, an upper portion of the yoke 104 can be constructed to surround a tapered lower portion of the strut or shock 102 in the assembled condition. In at least one embodiment, the lower portion of the strut or shock 102 can be secured or fastened to the upper surrounding portion of the yoke 104 using a bolt 113 and washer. However, other attachment means are possible such as, without limitation, a collar, bracket, annular clamp, screws, and the like. In at least one embodiment, the lower portion of the strut or shock 102 and the upper portion of the yoke 104 can include aligned apertures or bosses for receiving a cross pin 114 to secure the bolt 113 in the assembled condition. The cross pin 114 can be a threaded bolt and nut assembly, as shown in
With respect to
According to various embodiments, the air bag 170 can be a rubber airbag which sits on top of the piston 160. Furthermore, the air bag 170 can be fastened or attached to the piston 160 by a locking bead 162 which attaches the air bag 170 to the piston 160. In various embodiments, the air bag 170 can fold over an outside or exterior portion 163 of the piston 160 as the air spring 101 is compressed. In addition, in various embodiments, the piston 160 can have an annular opening or aperture 164 near the top of the hydraulic cylinder 180 through which air can flow between an interior portion of the air bag 170 and an interior portion of the piston 160 such that air pressure is equalized between the airbag 170 and the piston 160. In at least one embodiment, there is no communication between the air spring 101 and the hydraulic cylinder 180 through which either air or pneumatic fluid can flow. According to various embodiments, the air bag 170 can include a bladder or membrane that is air tight or otherwise impervious to transmission of gas through the membrane. In at least one embodiment, the gas impervious membrane can be formed using a flexible anti-ballistic material such as, for example, Kevlar™.
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According to various embodiments, the air spring 101 can include a valve 171 for adding to and removing from the air bag or bladder 170 a gas such as air under control of a processor or control logic. By controlling the gas pressure inside the bladder, the volume of the air bag 170 can be adjusted in order to raise or lower a ride height of the trailer frame to achieve a desired height of the frame above a driving surface.
In various embodiments, the volume of the air bag 170 for each of a number of integrated air spring damper assemblies 100 (for example, two) can be independently adjusted such that the corresponding frame side, which may be associated with one or more wheels, can be independently raised and lowered. As such, embodiments can provide a variety of ride height modes or adjustments including, without limitation, a maximum ride height mode in which the vehicle chassis and all of the integrated air spring damper assemblies 100 of the trailer are at a maximum height above their respective axle(s) or driving surface, a minimum ride height mode in which the trailer frame and all of the integrated air spring damper assemblies 100 of the trailer are at a minimum height above their respective axle(s) or the driving surface, a run flat mode in which one side of the trailer frame (two-wheeled trailers), or in which the three corners of the trailer relative to the corner to which the flat tire is most nearly located (four or more wheeled trailers), is lowered in order to reduce the weight that would otherwise be placed on the other side of the trailer frame (two-wheeled trailers) or on a second portion of the trailer frame nearest to the damaged tire (four or more wheeled trailers), and a side slope mode in which one side of the trailer is lowered (e.g., the upslope side) to its lowest ride height setting and the other side of the trailer (e.g., the downslope side) is raised to its highest setting. In each such mode, the integrated air spring damper assembly 100 provides translational movement for suspension jounce and rebound of the integrated air spring damper assembly 100 along the suspension travel direction 140.
In particular, various embodiments can provide a controllable variable ride height that is adjustable in response to signals from a controller. For example, with respect to
According to various embodiments, the manual three-position control valve 607 can have an open position in which air or gas can be exhausted from the air spring 101 to lower the ride height of the trailer, a closed position to maintain a current ride height of the trailer, and a third position connecting the air spring 101 valve 171 to the accumulator 606 for air or gas to flow from the accumulator 606 to the air spring 101 to raise the ride height of the trailer. Thus, the manual three-position control valve 607 can be manually actuated to raise or lower the ride height of the trailer 620 when the trailer is not connected (via interface 630, for example) to the drive vehicle 610.
Furthermore, in various alternative embodiments, the trailer 620 can be fully autonomous with respect to a drive vehicle 610. In such embodiments, for example, the trailer can have an internal power supply such as a battery, as well as its own suspension controller 601, electrical air compressor/pump 602, air accumulator 606, manifold 603, etc. In such embodiments, therefore, the trailer 620 can be operated by itself or controlled by the drive vehicle suspension control system.
Furthermore, in at least one embodiment, a single manual three-position control valve 607 can be provided for the trailer 620. Alternatively, one manual three-position control valve 607 can be provided for each integrated air spring damper assembly 100 associated with a particular wheel of the trailer 620, or one manual three-position control valve 607 can be provided for each side of the trailer 620.
In various embodiments, the controller 601 can be coupled to the pump 602, manifold 603, and ride height sensor 121 using an interface 630. The controller 601 can also be coupled to an input device or input means such as, for example, a keypad or a plurality of keypads, buttons, switches, levers, knobs, an interactive Liquid Crystal Display (LCD), touchscreen (not shown), for receiving a requested ride height input.
In various embodiments, controller 601 can output control signals to pump 602 and to manifold 603 in the form of one or more digital control words in which the contents of the various bit fields of each control word contain command parameter information that is received and interpreted by the pump and the manifold as a command or mode selection parameter or setting.
Controller 601 can execute a sequence of programmed instructions. The instructions can be compiled from source code instructions provided in accordance with a programming language such as C++. The instructions can also comprise code and data objects provided in accordance with, for example, the Visual Basic™ language, or another object-oriented programming language. In various embodiments, controller 601 may comprise an Application Specific Integrated Circuit (ASIC) including hard-wired circuitry designed to perform the operations described herein. The sequence of programmed instructions and data associated therewith can be stored in a computer-readable medium such as a computer memory or storage device which may be any suitable memory apparatus, such as, but not limited to ROM, PROM, EEPROM, RAM, flash memory, and the like.
In various embodiments, controller 601 may communicate with integrated air spring damper assembly 100, pump 602, manifold 603, and other vehicle subsystems in any suitable manner. Communication can be facilitated by, for example, a vehicle data/command serial bus. In various embodiments, the interface 630 can comprise, for example, a parallel data/command bus, or may include one or more discrete inputs and outputs. As one example, controller 601 can communicate with integrated air spring damper assembly 100 using a J1939 bus. Various embodiments can also comprise an air bag pressure monitoring subsystem to which the controller 601 is coupled. In various embodiments, one integrated air spring damper assembly 100 can be provided for each independent multi-link suspension 10 for each wheel of the trailer. Furthermore, the controller 601 can be coupled to a manifold 603 and can be configured to control an output of the manifold by sending one or more commands to the pump 602 and to the manifold 603 to control a pressure and/or volume of each air bag or bladder. The accumulator 606 can store air or gas under pressure or provide a vacuum source for adding or removing air or gas in the air bag via the manifold 603 and/or the three-position control valve 607.
According to various embodiments, the controller 601 can be a processor, microprocessor, microcontroller device, or be comprised of control logic including integrated circuits such as, for example, an Application Specific Integrated Circuit (ASIC). The controller 601 can be operatively coupled to each ride height sensor 121 for receiving from the electrical signal output by the ride height sensor 121, which varies based on chassis ride height, via the interface 604. In various embodiments, the interface 604 can be an electrical interface according to a vehicle control standard.
In various embodiments, the pump 602 can include an engine driven air (gas) compressor which is connected to the accumulator 606. Alternatively, the pump 602 can further comprise an electric motor powered air (or gas) compressor which works in parallel with the engine-powered compressor. In such alternate embodiments, the electric motor powered compressor can operate in a silent watch mode as a backup to the engine-driven compressor. For each air bag or bladder 170, the pump 602 can output gas at a pressure higher than or lower than a pressure that exists in the air bag or bladder 170 via the valve means 171 and the manifold means 603 and accumulator 606. The pump 602 output via the accumulator 606 and manifold 603 can be coupled to the air bag or bladder 170 of each integrated air spring damper assembly 100 via an air line 605. In this way, the pressure of the gas in the air bag or bladder 170 is either increased or decreased by the pump 602. As the gas pressure insider the air bag or bladder 170 increases (decreases), the volume of the air bag or bladder 170 increases (decreases) accordingly. As the volume of the air bag or bladder 170 increases or expands, the ride height of the frame portion corresponding to the integrated air spring damper assembly 100 is raised. On the other hand, as the volume of the air bag or bladder 170 decreases or contracts, the ride height of the frame portion corresponding to the integrated air spring damper assembly 100 is lowered. The controller 601 can be configured to monitor the actual ride height of a frame portion corresponding to an integrated air spring damper assembly 100 using the ride height sensor(s) 121 to determine when a desired or requested ride height has been achieved. In various embodiments, the controller 601 can include a memory for storing ride height measurements received from the ride height sensors 121. In various embodiments, the memory can also store information defining the relationship between the pressure and/or volume of the air bag or bladder and a corresponding desired ride height for the integrated air spring damper assembly. For example, a look-up table can be provided using the memory from which the controller 601 can select an output command to send to the pump based on a difference in desired ride height as compared to the current ride height for a given integrated air spring damper assembly 100. The look-up table can further include for each desired ride height an associated air bag pressure and/or volume. Further, in various embodiments, if an air bag fails, is punctured, or otherwise loses pressure, the control system 600 can isolate the failed air bag from the other integrated air spring damper assemblies to prevent the remaining air springs 101 from losing pressure and to allow degraded mode operation.
With respect to
Control can then proceed to S710, at which the controller can select and output a command to the manifold to individually increase or decrease the gas volume in the air bags or bladders for the selected integrated air spring damper assemblies to achieve the desired ride height. According to various embodiments, this step can include selecting an output command to send to the pump based on a difference in desired ride height as compared to the current ride height for a given integrated air spring damper assembly.
Control can then proceed to S712, at which the controller can monitor the sensed ride height input received from the ride height sensor of each integrated air spring damper assembly. At S714, the controller can determine whether or not the actual ride height input received from the ride height sensor equals the requested ride height. If so, then control can proceed to S716, at which the controller can output a command to shut off the manifold and pump. If not control can return to S710 to continue the ride height adjustment process. After S716, control can proceed to S718, at which the method 700 terminates.
It will be appreciated that the modules, processes, systems, and sections described above can be implemented in hardware, software, or both. Also, the modules, processes systems, and sections can be implemented as a single processor or as a distributed processor. Further, it should be appreciated that the steps mentioned above may be performed on a single or distributed processor. Also, the processes, modules, and sub-modules described in the various figures of the embodiments above may be distributed across multiple computers or systems or may be co-located in a single processor or system. Exemplary structural embodiment alternatives suitable for implementing the modules, sections, systems, means, or processes described herein are provided below.
The modules, processors or systems described above can be implemented as a programmed general purpose computer, an electronic device programmed with microcode, a hard-wired analog logic circuit, software stored on a computer-readable medium or signal, an optical computing device, a networked system of electronic and/or optical devices, a special purpose computing device, an integrated circuit device, a semiconductor chip, and a software module or object stored on a computer-readable medium or signal, for example.
Embodiments of the method and system (or their sub-components or modules), may be implemented on a general-purpose computer, a special-purpose computer, a programmed microprocessor or microcontroller and peripheral integrated circuit element, an ASIC or other integrated circuit, a digital signal processor, a hardwired electronic or logic circuit such as a discrete element circuit, a programmed logic circuit such as a PLD, PLA, FPGA, PAL, or the like. In general, any process capable of implementing the functions or steps described herein can be used to implement embodiments of the method, system, or a computer program product (software program).
Furthermore, embodiments of the disclosed method, system, and computer program product may be readily implemented, fully or partially, in software using, for example, object or object-oriented software development environments that provide portable source code that can be used on a variety of computer platforms. Alternatively, embodiments of the disclosed method, system, and computer program product can be implemented partially or fully in hardware using, for example, standard logic circuits or a VLSI design. Other hardware or software can be used to implement embodiments depending on the speed and/or efficiency requirements of the systems, the particular function, and/or particular software or hardware system, microprocessor, or microcomputer being utilized. Embodiments of the method, system, and computer program product can be implemented in hardware and/or software using any known or later developed systems or structures, devices and/or software by those of ordinary skill in the applicable art from the function description provided herein and with a general basic knowledge of the mechanical and/or computer programming arts.
Moreover, embodiments of the disclosed method, system, and computer program product can be implemented in software executed on a programmed general purpose computer, a special purpose computer, a microprocessor, or the like.
It is, therefore, apparent that there is provided, in accordance with the various embodiments disclosed herein, an integrated trailer suspension damper assembly for a trailer that includes a trailer suspension damper, an air spring concentrically attached to an upper portion of the trailer suspension damper and having an end rotatably attached to a trailer frame, a yoke having an upper end fixedly attached to a lower portion of the trailer suspension damper and a lower end constructed to be rotatably attached to a lower wishbone control arm, and in which the integrated trailer suspension damper assembly is constructed to travel a maximum linear articulation distance. The maximum linear articulation distance can be, for example, 17 inches. The integrated trailer suspension damper assembly can be constructed to provide a suspension force to support various trailer weights such as, for example, at least 10000 pounds. Alternatively, the integrated trailer suspension damper assembly can be constructed to provide a suspension force to support a trailer weight of at least 25000 pounds.
The yoke lower end can further comprise first and second legs each having inner surfaces equidistantly disposed about and laterally extending in a direction of a suspension travel axis and constructed such that a shaft can pass between said first and second legs in a direction orthogonal to the suspension travel axis. The yoke lower end can be formed of a single integral component.
The air spring can include a gas impervious membrane enclosing an interior portion having a gas volume and a valve provided in communication with the interior portion. The integrated trailer suspension damper assembly can be configured to provide a variable ride height based on the gas volume by adjusting the gas volume of the interior portion using the valve. The gas impervious membrane can be formed using a flexible anti-ballistic material such as, but not limited to, Kevlar™.
While the invention has been described in conjunction with a number of embodiments, it is evident that many alternatives, modifications and variations would be or are apparent to those of ordinary skill in the applicable arts. Accordingly, Applicants intend to embrace all such alternatives, modifications, equivalents and variations that are within the spirit and scope of the appended claims.
