Multi-disc clutch lock with needle bearing axial preload
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Solution Overview
Problem
Existing multi-plate lock differentials react only after slip occurs, leading to delayed response in torque transmission.
Innovation Solution
Incorporation of needle bearings to transmit axial forces from axle bevel gears to pressure rings, combined with an actuator controlled by a control unit that converts vehicle CAN bus signals into control signals to manage the locking force via an intermediate gear and cam disk, enabling load-dependent blocking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a conventional multi-plate lock differential is used, then the differential can transmit torque between axle bevel gears, but the differential reacts only after slip occurs leading to delayed response
Solution Approach 1:
The patent applies preliminary action by using needle bearings to pre-load the disk packs axially based on drive torque before slip occurs. This creates a basic locking torque that activates the locking mechanism in advance, eliminating the delay inherent in conventional differentials that must first experience slip before reacting.
2Adaptability or versatility
If an actuator with intermediate gear and cam disk is added to control locking force, then the locking force can be controlled actively, but the device complexity increases
Solution Approach 1:
The patent uses an intermediate gear and cam disk as intermediary elements to convert the actuator's rotary movement into axial lifting movement of the pressure piece. This mechanical translation mechanism enables controlled locking force adjustment while maintaining a relatively simple actuator design, as the intermediate components facilitate the motion conversion without requiring complex control systems.
3Speed
If needle bearings are used to transmit axial forces to pressure rings, then a basic locking torque acts depending on drive torque enabling faster reaction, but the manufacturing precision requirements increase
Solution Approach 1:
The needle bearings are positioned to be pre-loaded by the drive torque itself, which automatically generates the axial forces needed to load the disk packs. This self-service mechanism means the system uses its own operating forces (drive torque) to activate the locking function, reducing the need for external precision adjustment mechanisms and simplifying manufacturing requirements while maintaining fast response.
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 setup allows for a faster reaction to torque changes without initial slip, enhancing the differential's responsiveness and control over locking force.
Implementation Method 1
bearings that transmit axial forces resulting from the bevel gears of the axle bevel gears (12, 13) to the pressure rings (2, 3)
Implementation Method 2
the rotational movement of the actuator (14) is converted into an axial lifting movement via an intermediate gear (15) and a cam disc (16)
Implementation Method 3
Under load, axial forces are generated on the sloping contact surfaces (5) of the differential spider (1) on the pressure rings (2, 3), which press the disk pack (6, 7) together
Data Source
Figure 1
AI summary
The invention relates to a multi-disc clutch lock having a differential housing in which a differential pinion between axle bevel wheels, disc sets between the axle bevel wheels and the differential housing is untwisted, but thrust rings are arranged such as to be axially movable. The multi-disc clutch lock comprises outer discs of the disc sets that are non-rotatably connected to the differential housing and inner discs that are non-rotatably connected to the axle bevel wheels. As a result, an introduced driving torque is transmitted via the differential pinion to the thrust rings in order to press the disc sets together with the axial forces produced under load on the oblique contact surface of the differential pinion. An axially movable thrust piece is arranged between at least one disc set and the differential housing in order to transmit a lifting movement initiated by an actuator to the disc set. According to a method according to the invention for operating such a multi-disc clutch lock, a multi-disc clutch lock is then applied to a disc set by an actuator, wherein the actuator is activated by a control device that has software which converts the signals coming from a vehicle CAN bus into a control signal for the actuator using a control logic.