Segmented Brake Pistons in Mobile Machine Axles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing axle designs for mobile work machines, such as industrial trucks, face high manufacturing costs and complex production processes due to large-diameter components like annular pistons and seals, which increase the volume of pressure medium required for actuation and lead to high piston friction and difficulty in bleeding the service brake.
Innovation Solution
The use of multiple small-diameter brake pistons arranged in bores within the axle housing, which reduces manufacturing complexity and cost, requires less pressure medium for actuation, and features low friction due to smaller diameters, allowing for easier bleeding and improved surface pressure distribution through a pressure plate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If a large-diameter annular piston is used for the service brake, then the braking force is sufficient, but the manufacturing cost increases and the device complexity increases
Solution Approach 1:
The patent divides the single large-diameter annular piston into multiple small-diameter brake pistons (typically 2-4 pistons) arranged in a circular pattern. Each piston is contained in its own bore and acts on the brake rotor through a pressure plate. This segmentation reduces manufacturing complexity and cost while maintaining sufficient braking force through the combined action of multiple pistons.
2Force
If a large-diameter annular piston is used for the service brake, then the braking force is sufficient, but the volume of pressure medium required increases
Solution Approach 1:
By segmenting the single large piston into multiple small pistons, the total volume of pressure medium required is significantly reduced. Each small piston requires only a small volume of pressure medium in its individual bore, whereas the large annular piston required a large volume to accommodate the entire pressure medium chamber.
3Force
If a large-diameter annular piston is used for the service brake, then the braking force is sufficient, but the piston friction increases
Solution Approach 1:
The patent segments the single large piston into multiple small pistons, which reduces the frictional resistance. Each small piston has a smaller surface area in contact with its sealing elements, resulting in lower friction forces. The combined effect of multiple low-friction small pistons is less resistance than a single high-friction large piston.
4Force
If a large-diameter annular piston is used for the service brake, then the braking force is sufficient, but the difficulty of bleeding the brake increases
Solution Approach 1:
By dividing the brake system into multiple small piston bores, the bleeding process becomes easier. Each small bore can be bled independently or collectively with less effort compared to a large annular chamber. The smaller volume of pressure medium in each bore allows air bubbles to be more easily purged during the bleeding process.
5Shape
If a stepped housing recess with complex geometry is used for the annular piston, then the piston can be properly positioned, but the manufacturing complexity increases
Solution Approach 1:
The patent replaces the complex stepped housing recess with simpler cylindrical bores for each small piston. The positioning and sealing functions previously achieved by the stepped geometry are accomplished through simpler means such as piston pins, retaining rings, or simple shoulder features in each bore, significantly reducing manufacturing complexity.
6Reliability
If large-diameter seals are used for the annular piston, then the sealing effectiveness is sufficient, but the manufacturing cost increases
Solution Approach 1:
The patent uses multiple small-diameter seals, one for each small piston bore, instead of a single large-diameter seal for the annular piston. The total sealing effectiveness is maintained through the combined action of multiple small seals, while the manufacturing cost is reduced due to the smaller size and lower material cost of each individual seal.
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 results in a cost-effective, easily manufacturable, and efficient braking system with reduced friction and pressure medium volume, enabling effective actuation and easy maintenance of the service brake.
Implementation Method 1
an energy storage device which can be acted upon by a spring force in the direction of a braking position
Implementation Method 2
by energizing an electromagnetic coil body into a release position
Implementation Method 3
with the bores being able to be acted upon by a hydraulic braking pressure
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to an axle (1) of a mobile working machine, in particular a forklift truck, with at least one axle shaft (3a; 3b) and with a braking device (5) comprising a parking brake (10) and a hydraulically actuated service brake (20), wherein the parking brake (10) is designed as a storage brake (11) which can be actuated into a braking position by an energy storage device (5) and into a release position by means of a brake release actuator (12), and wherein the hydraulically actuated service brake (20) comprises a hydraulically actuated brake piston assembly (21), wherein the braking device (5) comprises at least one brake rotor (7a; 7b) cooperating with the axle shaft (3a; 3b) and at least one brake stator (8) cooperating with an axle housing (2) of the axle (1), which are used to generate a braking torque for the parking brake (10) and the service brake. (20) can be combined to form a co-operative relationship.According to the invention, the brake piston assembly (21) has at least two brake pistons (25a) which are each arranged to be longitudinally displaceable in a bore (26a) of the axle housing (2), wherein the bores (26a) can be subjected to a hydraulic brake pressure.