Controllable Coupling Assembly for Electronic Vehicular Transmission
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Solution Overview
Problem
Powershift transmissions experience tip-in clunk and shift harshness due to the absence of a torque converter, leading to noise and mechanical linkage issues during acceleration from coasting, which conventional automatic transmission control strategies fail to adequately address without compromising driver expectations and performance.
Innovation Solution
A controllable coupling assembly with a sensor and electromechanical component that includes a locking element and magnetic field sensing element, generating a variable magnetic field to control rotation and prevent overrunning, integrated into an electronic vehicular transmission system to manage torque transfer and reduce noise and harshness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a torque converter is used in conventional automatic transmissions to smooth torque transfer, then shift harshness and tip-in clunk are reduced, but the transmission becomes bulkier and less efficient due to parasitic losses
Solution Approach 1:
The patent extracts the torque smoothing function from the traditional torque converter and implements it through a controllable coupling assembly with locking members and a slide plate. This assembly can selectively engage to provide torque converter-like smoothing effects during specific operations (reverse-to-forward shifts, tip-in conditions) while allowing direct mechanical coupling during normal operation, thereby eliminating continuous parasitic losses while maintaining harm reduction when needed.
Solution Approach 2:
The coupling assembly employs dynamic control through a slide plate that can move between positions to engage or disengage locking members. This dynamic mechanism allows the transmission to switch between coupled and uncoupled states based on operating conditions, providing torque smoothing only when necessary (during shifts or tip-in) rather than continuously, thus reducing energy losses while maintaining performance when required.
2Object-affected harmful factors
If a controllable coupling assembly with sensor and electromechanical component is integrated, then precise control over torque transfer is achieved reducing tip-in clunk and shift harshness, but device complexity increases
Solution Approach 1:
The coupling assembly serves multiple functions: it acts as a one-way clutch for normal overrunning, provides bidirectional locking through engageable locking members for shift control, and enables tip-in clunk reduction through sensor-monitored electromagnetic actuation. By consolidating these diverse functions into a single integrated assembly rather than separate components, the patent reduces overall system complexity while achieving comprehensive noise and harshness control.
Solution Approach 2:
The patent replaces complex mechanical sensing and control systems with an electromagnetic actuator and sensor combination. The sensor detects rotational speed and position, and the electromagnetic component actuates the slide plate and locking members based on electronic control signals, substituting purely mechanical linkages with electro-mechanical control that is more compact and easier to integrate while achieving precise torque transfer control.
3Adaptability or versatility
If locking members and slide plate are added to create selectable one-way clutch, then control over rotation direction is improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the locking members and slide plate into a single integrated coupling assembly rather than separate components. The locking members are positioned within recesses of the coupling member, and the slide plate integrates with the housing to provide unified control. This consolidation reduces the number of discrete parts that need to be manufactured and assembled, simplifying production while maintaining the versatile control capability across multiple operating modes.
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 effectively eliminates tip-in clunk and shift harshness by providing precise control over torque transfer, reducing parasitic losses and mechanical noise, while maintaining performance and driver expectations, and is resistant to environmental factors like hot oil and contaminants.
Implementation Method 1
The sensor senses magnetic flux to produce an electrical output signal indicative of a speed of rotation of the coupling member
Implementation Method 2
A variable magnetic field is generated in response to rotation of the locking formations past the sensor
Data Source
AI summary
An electronic vehicular transmission including a sensor for providing an electrical signal for electronic transmission control is provided. The transmission includes a transmission case and a controllable coupling assembly including a coupling member supported for rotation within the case about a rotational axis. The coupling member has a coupling face oriented to face radially with respect to the axis and has a set of ferromagnetic or magnetic locking formations. An electromechanical component includes a locking element and a sensor. The component is mounted to and extends into the case so that both the locking element and the sensor are in close-spaced opposition to the coupling face. The sensor senses magnetic flux to produce an electrical output signal indicative of a speed of rotation of the coupling member. A variable magnetic field is generated in response to rotation of the locking formations past the sensor.