Cross-Groove Constant Velocity Joint for Large Operating Angles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fixed type constant velocity universal joints face issues with maintaining constant velocity characteristics, transmission efficiency, and durability when operating angles exceed 50°, leading to disturbances in the balance of internal forces and potential loss of ball contact with track grooves.
Innovation Solution
A fixed type constant velocity universal joint with cross track grooves, where the track grooves of the outer and inner joint members are inclined in opposite directions, and the curvature centers are aligned with the joint center, allowing balls to project from the outer joint member at large angles while maintaining contact and balancing forces on the cage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the outer joint member length is shortened to prevent interference at large operating angles, then interference is avoided, but the track grooves become shorter and balls lose contact
Solution Approach 1:
The track grooves are designed with curved paths that follow spherical geometry, allowing balls to maintain contact through curvature-based guidance rather than linear track extensions. The curved track groove paths enable balls to navigate large operating angles while staying engaged with the joint members.
Solution Approach 2:
The track grooves of the outer and inner joint members are configured with asymmetric inclination directions - outer joint member grooves incline in one direction while inner joint member grooves incline in the opposite direction. This asymmetric configuration creates a balanced force system that maintains ball contact at large operating angles.
2Length of stationary object
If the pitch circle diameter of balls is increased to elongate track grooves, then track groove length increases, but the outer diameter and weight of the outer joint member increase
Solution Approach 1:
The curved track groove paths utilize spherical geometry to achieve longer effective contact paths without increasing the outer diameter. The curvature allows balls to travel longer distances along the groove path while remaining within the same radial envelope, avoiding weight increase.
Solution Approach 2:
The track grooves are configured in three-dimensional curved paths rather than simple linear or planar grooves. This dimensional complexity allows longer effective track lengths to be achieved within the same outer diameter by utilizing spatial curvature rather than radial expansion.
3Adaptability or versatility
If track grooves have tapered shape extending radially outward to achieve large operating angle, then operating angle increases, but outer diameter must be increased
Solution Approach 1:
The track grooves follow curved spherical paths rather than radially tapered straight lines. This curvature allows the grooves to achieve the necessary angular range while maintaining a constant outer diameter, as the curved paths accommodate angular displacement without requiring radial expansion.
Solution Approach 2:
The groove geometry parameters are optimized with specific curvature radii and inclination angles that allow large operating angles to be achieved through angular configuration rather than radial dimension changes. The groove depth, curvature, and inclination are parameterized to decouple operating angle from outer diameter.
Data Source
Figure 1a~1b
Figure 2a~2b
Figure 3a~4
AI summary
Provided is a fixed type constant velocity universal joint (1) in which a raceway center line (X) of a track groove (7) of an outer joint member (2) includes at least an arc-shaped portion having a curvature center that has no offset with respect to a joint center (O) in an axial direction, in which a plane (M) including the raceway center line (X) and the joint center (O) is inclined with respect to an axis (N-N) of a joint, and the track groove (7) is formed with such an inclination direction of the plane (M) that the track grooves (7) adjacent to each other in a circumferential direction are inclined in opposite directions, in which a raceway center line (Y) of a track groove (9) of an inner joint member (3) is formed so as to be mirror-symmetric with the raceway center line (X) of the paired track groove (7) of an outer joint member (2) with a plane (P) including the joint center (O) and being orthogonal to the axis (N-N) of the joint in a state of an operating angle of 0° as a reference, in which the fixed type constant velocity universal joint (1) has an operation mode in which, when a maximum operating angle is taken, at least one of torque transmission balls (4) that moves toward an opening side of the track groove (7) of the outer joint member (2) loses a contact with an opening-side end portion of the track groove (7) of the outer joint member (2), and in which, under the state of the operating angle of 0°, an end portion of a cage (5) projects from the opening-side end portion of the outer joint member (2) in the axial direction.