The present disclosure generally relates to articulated and multi-articulated road vehicles and, more particularly, to an articulation system to couple together two adjacent units of an articulated or multi-articulated road vehicle.
Articulation systems for commercial road vehicles including low-floor commercial vehicles, such as articulated buses or bi-articulated buses, are well known. Such systems typically comprise two rigid frames fixed to each vehicle units and linked by a pivoting platform at the floor level. The system is typically enclosed by flexible and folding bellows (or sometimes corrugated bellows) inside and outside of the articulation. Such an articulation system is typically about 1.6-meter long. This space between two vehicle units is generally considered as of limited use with room for few standees. To overcome this shortcoming, a common trend is to figure out how to minimize the space the articulation occupies to accommodate another row of seats in the vehicle units.
Most of known bus articulations were designed for one of the two traditional concepts, pusher or puller vehicles. Pusher vehicles have the driving axle, engine and transmission in the trailer unit. Puller vehicles have the drivetrain in the leading unit. Except for the leading unit, all following units have only one axle on the rear. With the advent of electric drivetrains, more advanced road vehicle concepts are now considering vehicle units with two axles where at least one is a drive axle. Prior art articulation systems provide three degrees of freedom, corresponding to the three relative rotation motions between two units of a vehicle. This function is generally integrated into the pivoting platform at the floor level which comprises a roll joint, a pitch joint and a yaw (buckling) joint with damping mechanisms. However, articulated road vehicles having a front and a rear axle on each unit will require the articulation system to have a fourth degree of freedom corresponding to the up and down translation motion between the units.
With known articulation systems, the maximum turn angle is typically 55 degrees. More advanced multi-articulated road vehicle concepts where each unit has two axles and where all axles are steerable may benefit from the ability to reach a maximum turn angle of 90 degrees
There is, thus, a need to provide a new intermediate passenger-carrying compartments acting as an articulation system for road vehicles characterized by an improved maneuverability and additional useable interior space.
Therefore, in accordance with a general aspect of the present disclosure, there is provided an articulation system that may permit a maximum turn angle of 90 degrees between two units of an articulated or multi-articulated road vehicle, the articulation system having four degrees of freedom (rolling, pitching, yawing and vertical translation). At least some of said degree of freedom may also have damping and control mechanisms.
According to another general aspect, there is provided an articulation system adapted for vehicles having a plurality of units where each unit has a front and a rear axle.
In accordance with another general aspect, there is provided an articulation system between first and second vehicle units of an articulated road vehicle, the system including a vertical cylinder with two facing openings for permitting passage of passengers therethrough and comprising two interconnecting structures rotatable around the cylinder and joined respectively to the first vehicle unit and the second vehicle unit.
In accordance with a further general aspect, there is provided an articulation system for interconnecting a first and a second vehicle unit of an articulated road vehicle, the articulation system comprising: a central element including a vertical cylinder with left and right arcuate walls extending between two facing openings for permitting passage of persons therethrough; and first and second interconnecting structures joined to the central element, the first and second interconnecting structures adapted to be respectively attached to the first vehicle unit and the second vehicle unit on opposed sides of the central element; each of said first and second interconnecting structures comprising a pitch joint member and a yaw joint member; said pitch joint member comprising a frame perpendicular to a longitudinal axis of a corresponding one of the first and second vehicle units and a pitch hinge mechanism at a floor level to interconnect with the corresponding one of the first and second vehicle units; said yaw joint member comprising a frame perpendicular to the longitudinal axis of the corresponding one of the first and second vehicle units and left and right arcuate walls juxtaposed to said left and right arcuate walls of the vertical cylinder and rotatable around said vertical cylinder; the frame of the pitch joint member and the frame of the yaw joint member being juxtaposed and mechanically linked to jointly form a planar roll joint mechanism.
In accordance with a still further general aspect, there is provided an articulation system between first and second vehicle units of an articulated road vehicle, the system including a vertical cylinder with two facing openings for permitting passage of passengers therethrough and comprising two interconnecting structures rotatable around the cylinder and joined respectively to the first vehicle unit and the second vehicle unit.
According to still another aspect, rather than providing an articulation in the form of a low-platform with a swivel joint controlling the yawing movement as usually seen for articulated buses, there is provided an articulation in the form of a vertical cylinder where the arcuate walls create the swivel or yaw joint. According to one aspect of the system, the usual flexible and folding bellows are replaced by a rigid structure of moving parts.
In accordance with another aspect, there is provided an articulation system having a roll joint mechanism that spreads the mechanical stress over a planar surface rather than having it concentrated into a localized point.
In accordance with a still further aspect, there is provided an articulation system which is designed to provide more useful interior space, large enough to be a passenger-carrying compartment, and to allow for curved rows of seats along the interior arcuate walls of the articulation.
According to still a further aspect, there is provided a mechanical linkage mechanism using four pairs of piggy-back hydraulic cylinders to control the angular position of the first unit and of the second unit.
In accordance with a still further general aspect, there is provided an articulation system for interconnecting a first and a second vehicle unit of an articulated road vehicle, the articulation system comprising at least one planar roll joint mechanism having two frames juxtaposed, said two frames having interlocking thread patterns on respective interfacing faces thereof, the interlocking thread patterns including arcs of concentric circles; said planar roll joint mechanism being rotatable according to said interlocking thread patterns.
The interconnecting structures (5) can be interconnected through mechanical linkages (10) (shown in
According to one embodiment, each of the arcuate walls (4) of the central element (2) comprises a fixed panel and sliding and overlapping panels. According to another embodiment, each of the arcuate walls of a yaw joint member (5b) comprises a fixed panel and sliding and overlapping panels. According to a further embodiment, each of the arcuate walls of the central element (2) and of the yaw joint members (5b) comprises a fixed panel and sliding and overlapping panels. The overlapping panels can expand or contract the arcuate walls of a yaw joint member (5b) and/or of the central element (2) according to the turn angle of the articulation system, as shown in
As illustrated in
As shown in
Those skilled in the art will understand that the articulation system may incorporate well known damping and spring-loaded mechanisms, such as the hydraulic cylinders (13) in the mechanical linkage mechanism (10) for the yaw motion, to control each of the four degrees of freedom. It may also incorporate well known flexible waterproofing membranes or equivalent means to provide watertight sealing for each joint element.
According to one embodiment, the central element (2) has a diameter in the order of 2.5 meters and each arcuate interior wall can accommodate a curved row of seats. Rather than trying to minimize the length of the articulation system, there is provided an articulation system which is longer and constructed with rigid wall panels, creating useful interior space for passengers, and allowing for a better management of the relative motion between the two vehicle units.
It is contemplated to use the articulation system (1) for articulated or multi-articulated road vehicles, such as city buses, trambuses and even trucks, where each vehicle unit comprises a font and a rear axle. More specifically, it is contemplated to use the articulation system (1) for multi-articulated vehicles where all axles are steerable, and all rear axles of each unit are electric drive axles.
Filing Document | Filing Date | Country | Kind |
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PCT/CA2018/050604 | 5/24/2018 | WO | 00 |
Number | Date | Country | |
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62512334 | May 2017 | US |