Electric Axle Busbar Routing Along Suspension Links

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Solution Overview

Problem

In electric trucks, the connection between the energy storage system and the electric motors through high-voltage cables is prone to damage due to stretching and bending caused by suspension movements, leading to potential friction and fatigue issues.

Innovation Solution

The use of busbars that are shaped to follow the suspension components, including coil springs, to route power supply, eliminating the need for loose cables and minimizing bending radii, with the busbars being secured to a reaction rod or leaf spring system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If high-voltage cables are used with free length to absorb suspension movements, then the cables can accommodate the movement between axle and chassis, but the cables are subject to friction, bending, stretching, and fatigue damage

Engineering Contradiction:
Improveaccommodation of suspension movementVSAvoidcable damage risk
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent extracts the problematic free-length cable section and replaces it with a rigid busbar structure that is integrated into the suspension components. The busbar is securely attached to the reaction rod or leaf spring, eliminating the need for loose cable sections that are prone to damage from bending and friction.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The busbar is designed with curved portions that follow the natural curvature of the suspension components (reaction rod or leaf spring). This curved design allows the power supply routing to adapt to suspension movements while maintaining structural integrity and avoiding sharp bends that would cause fatigue.

Inventive Principle:
Principle #14Spheroidality (Curvature)

2Productivity

If the electric motor is directly fastened to the axle body to eliminate propeller shaft, then space is freed for ESS and friction losses are reduced, but the power supply routing device is subjected to stretching and elongation from suspension movements

Engineering Contradiction:
Improvepowertrain efficiencyVSAvoidpower supply routing durability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent merges the power supply routing device with the suspension components themselves. The busbar is integrated into the reaction rod or leaf spring structure, combining the functions of mechanical support and electrical power transmission into a single robust assembly that moves together as one unit.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The busbar incorporates curved portions that match the curvature of the suspension components, allowing the power supply route to flex and adapt to suspension movements without creating stress concentration points or excessive bending radii that would lead to fatigue failure.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Reliability

If busbars are shaped to follow suspension components, then the routing is compact and robust with minimized bending radii, but the busbar design becomes more complex

Engineering Contradiction:
Improvepower transmission durabilityVSAvoidbusbar geometry
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The busbar serves multiple functions simultaneously: it provides electrical power transmission, structurally integrates with the suspension system, and adapts to movement through its curved geometry. This multi-functionality justifies the increased geometric complexity by consolidating what would otherwise require separate components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4674650A1A vehicle electric axle
Publication Date: 2026.01.07 VOLVO TRUCK CORP
  • EP4674650A1 patent drawingFigure 1~2
  • EP4674650A1 patent drawingFigure 3~4
  • EP4674650A1 patent drawingFigure 5~6

AI summary

The invention relates to a vehicle electric axle, comprising at least one electric motor and a suspension system including a longitudinal element (7) which is a reaction rod (7) or a leaf spring (17), the longitudinal element (7) being rotatably mounted at one end around a reaction rod bracket (8) and at the other end around a dampening member (6); wherein said at least one electric motor includes a power supply routing device to be connected to an electrical power source, said power supply routing device comprises at least one busbar (12), a straight portion (12a) of which extending longitudinally along the longitudinal element (7, 17), and wherein said at least one busbar (12) includes two curved portions (12b, 12c) forming two cavities each receiving at least part of a longitudinal end (7c, 7d) of the longitudinal element (7).