Piezoelectric Generator Radial Clamping Eccentric Shaft
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional piezoelectric generators face challenges in manufacturing complexity, maintenance difficulties due to closed housing designs, and high installation space requirements, along with issues in setting suitable gap sizes that prevent warping and ensure contact between solid-state actuator units and the drive body.
Innovation Solution
A piezoelectric generator design featuring a drivable eccentric shaft with a stroke transmission device that radially clamps piezo units via a housing with a through-opening, allowing external access for maintenance, and utilizing a resiliently braced transmission pin and guide sleeve for efficient force transfer, minimizing friction and shearing forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the piezo units are clamped between an outer ring and an inner ring that can be displaced eccentrically, then axial shearing forces and frictional forces are minimized, but the structure becomes difficult to manufacture due to small manufacturing tolerances required
Solution Approach 1:
The generator is divided into modular components: a stationary outer ring with piezo units, a movable inner ring, and a separate eccentric shaft. This segmentation allows each component to be manufactured and assembled independently, reducing the cumulative tolerance requirements while maintaining the force-minimizing clamping structure.
Solution Approach 2:
A bearing is introduced as an intermediary element between the eccentric shaft and the inner ring. This bearing mediates the force transmission, reducing direct frictional contact and shearing forces between the shaft and piezo unit structure, while allowing for easier manufacturing of each component separately.
2Device complexity
If the generator housing is completely closed, then the structure is compact, but maintenance work requires complete dismantling of the generator
Solution Approach 1:
The housing is segmented into a stationary outer housing and a movable inner ring assembly. The inner ring can be accessed and maintained independently by removing only specific components rather than dismantling the entire generator, enabling partial maintenance while maintaining a compact overall structure.
Solution Approach 2:
The inner ring is designed to be dynamically removable from the housing through a simple release mechanism. This allows the housing to transition from a closed state during operation to an open state during maintenance, providing ease of repair while maintaining structural integrity during normal use.
3Force
If excessive prestressing is applied to the piezo units, then the clamping force is sufficient, but the piezo units may be blocked or destroyed during operation
Solution Approach 1:
The prestressing force on the piezo units is made dynamic rather than static. The inner ring can move eccentrically to adjust the clamping force during operation, reducing peak stresses that would otherwise block or destroy the piezo units while maintaining sufficient average clamping force for effective energy generation.
Solution Approach 2:
A spring element is introduced to provide beforehand cushioning for the prestressing force. The spring absorbs excess force during operation, preventing the piezo units from being overloaded or blocked while maintaining adequate clamping pressure for effective function.
4Ease of manufacture
If stroke transmission devices are used to transmit the eccentric shaft stroke to piezo units, then prestressing can be easier to set, but the number of individual parts and installation space requirement increase
Solution Approach 1:
The stroke transmission function is merged directly into the inner ring structure. The inner ring itself serves as both the mounting structure for piezo units and the stroke transmission element, eliminating the need for separate stroke transmission devices and reducing the total number of parts while maintaining ease of prestressing setup.
Solution Approach 2:
The inner ring is designed with multi-functionality: it provides mounting for piezo units, transmits the eccentric shaft stroke, and enables adjustment of prestressing force. This universal design consolidates multiple functions into a single component, reducing part count and installation space while maintaining ease of setup.
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
The design simplifies manufacturing, enhances maintenance accessibility, reduces friction and shearing forces, and increases stability, resulting in a compact and efficient energy conversion system with reduced error-prone components and low friction losses.
Implementation Method 1
at least one piezo unit which can be clamped and generates an alternating current
Data Source
Figure 1
AI summary
The invention relates to a piezoelectric generator (1) that converts the kinetic energy of a driveable eccentric shaft (3) into electrical energy by clamping at least one piezoelectric unit (2). This generator comprises at least one piezoelectric unit (2) that can be clamped to generate an alternating current, a driveable eccentric shaft (3) that controls the clamping, and a stroke transmission device (40) through which the piezoelectric unit (2) is operatively connected to the eccentric shaft (3), so that the piezoelectric unit can be clamped essentially in the radial direction to the axis of rotation (5) of the eccentric shaft (3).Furthermore, the piezoelectric generator (1) comprises a housing (60) arranged around the eccentric shaft (3), to which the piezoelectric unit (2) is attached by means of a mounting device (70), wherein the piezoelectric unit (2) is arranged outside the housing (60) and the stroke transmission device (40) is operatively connected to the piezoelectric unit (2) via a through-opening (8) in the housing (60). The invention also relates to a vehicle, in particular a commercial vehicle, which includes such a piezoelectric generator (1).