Pneumatic Tandem Axle Stabilizer Bar Inversion
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Solution Overview
Problem
Current pneumatic tandem axle suspensions for heavy goods vehicles face challenges in achieving a compact design, increasing ground clearance, reducing weight and costs, while improving driving comfort and vibration transfer from axles to the cabin.
Innovation Solution
The stabilizer bars are positioned above the axles with pivot bearings mounted between the frame and air bellows, allowing for a more compact design and better absorption of forces, enabling lighter spring beams and increased ground clearance, and the cranked shape of traverse beams accommodates central axle parts, reducing obstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the stabilizer bars are positioned below the frame with pivot bearings on the spring beams, then the suspension provides adequate stability, but the design takes much space and restricts ground clearance while increasing weight
Solution Approach 1:
The patent inverts the conventional arrangement by positioning the stabilizer bars above the axles rather than below the frame. The traverse beams are mounted between the bottom of the frame and the air bellows, with legs extending downward to connect to the axles. This inversion resolves the contradiction by achieving axle stability while increasing ground clearance, as the stabilizer mechanism no longer occupies space that would otherwise be available for clearance.
Solution Approach 2:
The patent changes the spatial arrangement from a horizontal arrangement (stabilizer bars mounted on spring beams beneath the frame) to a vertical arrangement (traverse beams positioned between frame and air bellows, with legs extending downward). This dimensional reorganization allows the stabilizer function to be achieved without restricting ground clearance, effectively moving the stabilizing action to a different spatial dimension.
2Device complexity
If the stabilizer bars are positioned below the frame on spring beams, then the suspension structure is simple, but the spring beams must have solid construction and high weight to withstand high forces and torques
Solution Approach 1:
The patent inverts the mounting arrangement, positioning traverse beams between the frame and air bellows rather than mounting them on the spring beams. This inversion changes the load path and force distribution, allowing the spring beams to be lighter while still providing adequate support. The frame and air bellow mounting structure assumes the high forces and torques instead of the spring beams.
Solution Approach 2:
The patent introduces the air bellows and frame mounting structure as intermediary elements between the stabilizer function and the spring beams. The traverse beams connect to the frame and air bellows rather than directly to the spring beams, acting as intermediaries that transfer and distribute forces. This allows the spring beams to be lighter since they no longer directly bear the full stabilizer forces.
3Ease of manufacture
If the stabilizer bars are positioned below the frame, then the mounting is straightforward, but the design is not compact and restricts space underneath the frame
Solution Approach 1:
The patent inverts the conventional mounting approach by positioning the stabilizer traverse beams above the axles and between the frame and air bellows, rather than below the frame. This inversion resolves the space conflict by utilizing the vertical space between existing components (frame and air bellows) that would otherwise be unused, achieving a compact design without complicating the mounting process.
Solution Approach 2:
The patent nests the stabilizer traverse beams within the existing space between the frame and air bellows. The traverse beams are positioned in the vertical gap that already exists in the suspension assembly, effectively nesting the stabilizing function within the existing structural envelope. This nesting approach achieves compactness by utilizing otherwise wasted space rather than adding external mounting requirements.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design enhances driving comfort by reducing vibration transfer, improves road tracking, and decreases the overall weight and manufacturing costs of the suspension system.
Implementation Method 1
two pairs of air bellows are arranged between the spring beams and the frame, wherein each one pair of air bellows is arranged at one side (i. e. the left or right side) of the vehicle frame and comprises a front bellow and a rear bellow arranged in front of and behind the axle, respectively, to support the respective front or rear end of the spring beams at this side of the vehicle against the bottom of the frame
Implementation Method 2
Each one shock absorber is arranged to support one of the spring beams with respect to the frame
Implementation Method 3
These suspension and dampening means are installed underneath a frame forming the chassis of the vehicle
Data Source
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AI summary
Pneumatic tandem axle suspension for a pair of rear axles of a vehicle, in particular a heavy goods vehicle, comprising a front suspension portion and a rear suspension portion, each comprising spring beams arranged beneath a frame, two pairs of air bellows arranged at the vehicle frame, a pair of hydraulic shock absorbers and a triangular rod being pivotable linked to an upper center portion of the axle and the frame, and front hangers extending downward from the frame, each of the front and rear suspension portions comprising a pair of longitudinal rods extending between the front hangers and the spring beams, characterized in that each of the front and rear suspension portions comprises a stabilizer bar which is generally U-shaped and disposed above the axle, with a traverse beam and two legs extending from the ends of the traverse beam in a direction perpendicular to the axle, wherein the traverse beam is rotatable supported within a pair of pivot bearings mounted between the frame and an air bellow, such that the legs can perform a swiveling movement, and the ends of the legs being pivotable linked to the axle suspended by the respective suspension portion via generally perpendicular thrust rods and axle brackets on top of the axle, with each thrust rod being hinged to one leg end and to one axle bracket.