Slewing Drive Brake Mechanism Integrating Spider Member for Compact Axial Design
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Solution Overview
Problem
Existing slewing drive devices for construction machines, such as excavators, face challenges in increasing braking performance while minimizing axial size and reducing costs and assembly complexity, particularly due to the need for larger brake mechanisms and increased component counts.
Innovation Solution
A slewing drive device with a brake mechanism that integrates a rotating-shaft-side brake plate on the outer periphery of a spider member, which is rotatable with the spider supporting planetary gears, and a casing-side brake plate, allowing for increased brake effective radius without additional components or increased diameter, thus reducing axial size and enhancing assembly efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a brake mechanism is interposed between speed reducing units to increase brake effective radius, then braking performance is enhanced, but the axial size of the speed reducer increases
Solution Approach 1:
The brake mechanism is merged with the existing speed reducer structure by utilizing the casing and internal components. The brake piston, rotating shaft-side brake plate, and casing-side brake plate are integrated into the speed reducer's axial space without requiring external additions, thus enhancing braking performance while maintaining compact axial dimensions.
Solution Approach 2:
Instead of increasing the brake effective radius by extending the axial length, the invention utilizes the radial dimension by positioning brake plates at different radial distances from the rotation axis. The rotating shaft-side brake plate is positioned at a larger radial distance to maximize the brake effective radius within the existing axial space.
2Reliability
If a disc-shaped brake connecting member is mounted on the outer periphery of the rotating shaft to increase brake effective radius, then braking performance is enhanced, but the number of components and cost increase
Solution Approach 1:
The rotating shaft-side brake plate serves multiple functions: it acts as both a structural component of the brake mechanism and a functional element that transmits braking force. By making the brake plate an integral part of the speed reducer structure rather than a separate component, the invention reduces the total number of parts while maintaining braking effectiveness.
Solution Approach 2:
The invention extracts the essential braking function from a complex multi-component system and implements it using minimal components. By eliminating the disc-shaped brake connecting member and using only the necessary brake plates and piston, the solution achieves braking performance with reduced component count and lower cost.
3Reliability
If the outer diameter of the rotating-shaft-side brake plate is increased to increase brake effective radius, then braking performance is enhanced, but the assembling performance deteriorates
Solution Approach 1:
The brake mechanism is segmented into distinct, modular components including the brake piston, rotating shaft-side brake plate, and casing-side brake plate. Each component can be manufactured independently and assembled in a systematic sequence, improving assembling performance while allowing the brake plates to be optimized for maximum braking effectiveness.
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 configuration enhances braking performance by increasing brake effective radius, reduces costs by eliminating unnecessary components, and simplifies assembly by allowing easier replacement and adjustment of brake plates, while maintaining a compact axial size.
Implementation Method 1
a brake mechanism which generates a braking force against the rotation to be transmitted from the speed reducer to the driven unit... The rotating-shaft-side brake plate and the casing-side brake plate are brought into press contact with each other by a pressing force of the brake piston, whereby a braking force is exerted on the rotating shaft
Data Source
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Figure 2
AI summary
A drive device for a construction machine is provided with a speed reducer which transmits a rotation of a motor to a driven unit at a reduced speed; and a brake mechanism which generates a braking force against the rotation to be transmitted from the speed reducer to the driven unit. The speed reducer includes a rotating shaft disposed in a casing, and a planetary gear type speed reducing unit disposed in the casing. The speed reducing unit includes a sun gear, a ring gear, a planetary gear which is meshed with the sun gear and the ring gear, and a spider member which supports the planetary gear so that the planetary gear is rotatable. The brake mechanism includes a rotating-shaft-side brake plate provided on an outer periphery of the spider member in a state that the rotating-shaft-side brake plate is integrally rotated with the spider member, a casing-side brake plate provided on the casing, and a brake piston which generates the braking force by bringing the rotating-shaft-side brake plate and the casing-side brake plate to press contact with each other.