Actuator Assembly for Motor Vehicle Drive Train
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Solution Overview
Problem
Conventional hydraulic circuits in drive trains, especially in automated transmissions, fail to guarantee the actuation of parking locks under all operating conditions, particularly when using a pump driven by an internal combustion engine.
Innovation Solution
An actuator arrangement where a parking lock hydraulic cylinder is connected directly to a pump, allowing the parking lock arrangement to be actuated by changing the direction or speed of the pump, which also actuates the friction clutch, using a single electric motor and pump for both functions, enabling actuation independent of the drive motor's state and providing spatial and control advantages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional hydraulic circuit with a pump driven by an internal combustion engine is used, then the parking lock can be actuated when the engine is running, but the parking lock cannot be reliably actuated when the engine is not running
Solution Approach 1:
The patent replaces the mechanical engine-driven pump system with an electric motor-driven pump system. This substitution allows the parking lock to be actuated independently of the engine's operating state, as the electric motor can be controlled to operate the pump regardless of whether the engine is running or stopped, thereby achieving reliable parking lock actuation in all operating conditions.
Solution Approach 2:
The electric motor-driven pump system is designed to serve multiple functions: it can actuate both the friction clutch and the parking lock arrangement. By controlling the pump's speed and rotation direction, the system can provide hydraulic pressure to different actuators as needed, making the system versatile and adaptable to various operating states without requiring separate dedicated systems.
2Reliability
If separate actuators are used for the friction clutch and parking lock, then each component can be optimized independently, but the device complexity and installation space increase
Solution Approach 1:
The patent merges the actuation systems for the friction clutch and parking lock into a single integrated hydraulic system. Both components are actuated by the same electric motor-driven pump through a common hydraulic circuit, reducing the number of separate actuators and simplifying the overall system while maintaining the ability to independently control each component through electronic control of the pump's operation.
Solution Approach 2:
The single electric motor-driven pump is designed to perform multiple functions by directing hydraulic flow to different actuators based on control signals. The pump can selectively supply pressure to the friction clutch actuator or the parking lock actuator, or both simultaneously, providing a universal actuation source that reduces system complexity while maintaining component independence.
3Volume of moving object
If a single electric motor and pump are used to actuate both the friction clutch and parking lock, then installation space is reduced, but the control requirements become more complex
Solution Approach 1:
The patent employs dynamic control of the electric motor-driven pump to manage multiple actuators. The pump's rotation speed and direction are dynamically adjusted based on real-time control signals to provide the required hydraulic pressure to the friction clutch or parking lock as needed. This dynamic operation allows a single pump to replace multiple static pumps, reducing installation space while the control system manages the complexity through electronic regulation.
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 solution ensures the parking lock can be actuated in all operating states with a simple, space-efficient design, using existing control units and eliminating the need for additional electrical actuators, thus enhancing the reliability and integration of the actuator system in drive trains.
Implementation Method 1
an electric motor-driven pump (62, 72) is provided, which has a first pump connection (67, 77) and a second pump connection (82, 90)
Implementation Method 2
a first hydraulic clutch cylinder (17) is provided, which has a connection (C), and a second hydraulic clutch cylinder (19), which has a connection (D)
Data Source
Figure 1~2
Figure 3~4
AI summary
Actuator arrangement (60) for a drive train (10) comprising at least one friction clutch (16, 18) for transmitting drive torque and a gearbox (14), wherein the friction clutch (16, 18) can be actuated by means of a clutch hydraulic cylinder (17, 19) which is directly connected to a pump port (67, 77) of an electrically driven pump (62, 72) for actuating the friction clutch (16, 18) such that the friction clutch (16, 18) can be actuated by changing the speed of the pump (62, 72), and with a parking lock actuator device (44, 54; 108) for actuating a parking lock arrangement (30) of the drive train (10). The parking lock actuator assembly includes at least one parking lock hydraulic cylinder (44, 54; 108) which can be connected to the pump (62, 72) such that the parking lock assembly (30) can be actuated by changing the speed of the pump (62, 72). (Fig. 3)