Pivoting Headlamp Drive Shaft With Multi-Axis Spline Compensation
Solution Overview
Problem
Existing headlight designs face challenges in compensating for the displacement of the output head relative to the drive head due to the pivoting of the suspension element, which is typically addressed using complex and expensive solutions like flexible shafts or cardan joints.
Innovation Solution
The drive shaft features a multiple spline connection with shaft parts that can be axially displaced and pivoted about multiple axes, allowing for the transmission of rotational motion while accommodating vertical pivoting of the output head relative to the drive head, utilizing a splined connection with complementary external and internal hexagonal teeth for torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flexible shafts or cardan joints are used to compensate for the displacement of the output head relative to the drive head, then the displacement compensation is achieved, but the device complexity and cost increase
Solution Approach 1:
The drive shaft is divided into multiple shaft parts (first shaft part and second shaft part) that can move independently relative to each other. Each shaft part can pivot about different axes, allowing the system to compensate for displacement through the coordinated movement of segmented components rather than requiring a single complex flexible shaft or cardan joint assembly.
Solution Approach 2:
The shaft parts are designed with dynamic degrees of freedom, allowing them to pivot about multiple axes perpendicular to their rotation axes. This dynamic capability enables the drive shaft to adapt its configuration in real-time to compensate for the displacement caused by support means pivoting, replacing static complex compensation mechanisms with a more flexible and simpler dynamic system.
2Power
If conventional splined shafts are used to transmit torque while allowing axial displacement, then torque transmission and axial displacement are achieved, but pivoting about perpendicular axes is not possible
Solution Approach 1:
The splined connection between shaft parts is designed to allow not only axial displacement and torque transmission but also pivoting movements about axes perpendicular to the rotation axis. This dynamic design enables the shaft parts to change their relative orientation while maintaining torque transmission capability, providing both power transfer and adaptability.
Solution Approach 2:
By dividing the drive shaft into multiple independently pivotable shaft parts connected through splined connections, the system achieves both torque transmission and pivoting capability. Each shaft part can pivot relative to its neighbor, creating a segmented system that combines rigid torque transmission with flexible adaptability.
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 solution simplifies the compensation for displacement, providing a more cost-effective and flexible mechanism that allows for precise adjustment of the headlight's low beam distribution without the need for expensive flexible shafts or cardan joints, enhancing the headlight's adjustability and reliability.
Implementation Method 1
the shaft parts are connected to one another at first ends in the manner of a multiple spline connection such that they can be displaced axially and are non-rotatable in order to transmit the rotary motion
Implementation Method 2
a bevel gear which is connected to the second shaft part and with which the pinion engages
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The headlamp has a housing that acts as a bearing of a head on an input side. A drive shaft includes shaft sections (2), where one end of the shaft sections transmits a rotary motion. A multi-key joint interlink is provided between the shaft sections moveable in an axial direction in relation to one another and in a torque-proof manner. Rotary motion to be transmitted is revolved around axes of rotation in the shaft sections, where the shaft sections pivot in relation to one another around multiple axes perpendicular to the axes of rotation.