Cam Damper Bearing Assembly for Stable Low-Friction Torque Transmission
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Solution Overview
Problem
Existing damper devices experience instability and increased friction due to clearance between rollers and through-holes, leading to inefficient transmission of rotational driving force and manufacturing difficulties during assembly.
Innovation Solution
A damper device with an input and output shaft member, cam surfaces, and a damper bearing assembly where the damper bearings are supported by a bearing shaft orthogonal to the rotation axis, and an urging member ensures proper alignment and contact between cam surfaces, enhancing the stability and efficiency of rotational force transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If clearance is provided between rollers and through-holes of the retainer to enable roller rotation, then the rollers can rotate freely, but play is generated causing unstable rolling motion and increased friction
Solution Approach 1:
The damper bearing is segmented into an inner ring, outer ring, and rolling elements (balls or rollers). This segmentation allows each component to perform its specific function: the inner ring rotates with the input shaft, the outer ring remains stationary relative to the cam surface, and the rolling elements mediate between them, enabling free rotation without play while maintaining stable rolling motion.
Solution Approach 2:
The rolling elements (balls or rollers) act as intermediaries between the inner and outer rings. These intermediaries transfer the rotational motion from the input shaft to the output shaft while reducing friction through rolling contact, thereby enabling smooth rotation without generating play or instability.
2Ease of operation
If clearance is provided between rollers and through-holes of the retainer, then the rollers can rotate freely, but friction between rollers and cam surfaces increases
Solution Approach 1:
The patent replaces the traditional roller-based mechanical system with a ball bearing system. The ball bearings provide superior rolling contact that reduces friction more effectively than rollers. The spherical shape of the balls allows for more efficient force transmission and reduced contact friction, thereby reducing energy loss while maintaining free rotation capability.
3Device complexity
If the retainer is not fixed in position between the cam surfaces, then the structure is simpler, but assembly of rollers and retainer becomes difficult
Solution Approach 1:
The patent merges the retainer function into the damper bearing assembly itself. The outer ring of the damper bearing serves as the retainer, eliminating the need for a separate retainer component. This integration simplifies the overall structure while making assembly straightforward, as the bearing components can be assembled together as a single unit and then installed between the cam surfaces.
Solution Approach 2:
The damper bearing is pre-assembled with all its components (inner ring, outer ring, rolling elements, and cage) in a controlled manufacturing environment. This preliminary assembly ensures proper positioning and fit of all components before the entire bearing assembly is installed between the cam surfaces, greatly simplifying the final assembly process.
4Ease of manufacture
If clearance is provided between rollers and through-holes, then the rollers can be assembled, but the rolling motion becomes unstable and friction increases
Solution Approach 1:
The patent replaces the roller-based mechanical system with a ball bearing system. The ball bearings provide superior rolling contact that reduces friction more effectively than rollers. The spherical shape of the balls allows for more efficient force transmission and reduced contact friction, thereby reducing energy loss while maintaining free rotation capability.
Solution Approach 2:
The patent changes the geometric parameters of the rolling elements from cylindrical rollers to spherical balls. This parameter change fundamentally alters the contact mechanics, reducing point contact friction and improving rolling efficiency. The spherical geometry also allows for better load distribution and more stable rolling motion, thereby improving the efficiency of rotational driving force transmission.
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 solution improves the efficiency of rotational driving force transmission and manufacturing efficiency by stabilizing the rolling motion of the damper bearings and reducing friction, effectively addressing torque and speed fluctuations.
Implementation Method 1
an urging member urging the output side cam so that an opposing portion of the other of the input side cam and the output side cam abuts the outer peripheral portion of the damper bearing
Implementation Method 2
the outer peripheral portion pivotable around a bearing axis on an opposing portion of one of the input side cam and the output side cam
Data Source
AI summary
A damper device includes an input shaft member to which a driving force from a crankshaft of an internal combustion engine is input, an output shaft member capable of outputting the driving force transmitted from the input shaft member, an input side cam and an output side cam respectively connected to the input shaft member and the output shaft member, and a damper bearing pivotable on the input side cam or the output side cam, wherein a damper bearing assembly has a bearing shaft supporting a plurality of damper bearings, bearing axes of the plurality of damper bearings are arranged along a bearing shaft axis of the bearing shaft, the bearing shaft is orthogonal to a rotation axis, and a shaft support portion supporting the bearing shaft, is provided between the adjacent damper bearings of the damper bearing assembly.