Abstract:
A method for providing an active engine stop of the engine of a hybrid electric vehicle. The method utilizes the electric machine to oppose and rapidly stop the rotation of the engine at a controlled rate. The method includes the calculation of an input speed reduction trajectory using the engine speed when the active engine stop request is made and a predetermined speed reduction interval. The speed reduction interval is less than a time from the active stop request to the shutoff command to the electric machine The method provides rapid deceleration of the engine, particularly through the powertrain resonance speed, reducing the amount of vibration energy dissipated through the powertrain and chassis. The method removes the electric machine torques from the engine prior to achieving zero engine speed in order to avoid imparting a negative engine speed or counter-rotation of the engine.
Abstract:
A rotating clutch operably disposed between two rotating components includes a hydraulic operator having a piston and, on one side of the piston, an apply chamber or cavity and, on the opposite side of the piston, a balance chamber or cavity. The apply chamber is selectively provided with pressurized hydraulic fluid to engage and release the clutch to couple and de-couple the two rotating components. The balance chamber is provided with a flow of pressurized hydraulic fluid from the transmission lubrication system that flows through the transmission main shaft and flow restricting passages to the balance chamber. An exhaust port downstream of the balance chamber releases excess hydraulic fluid flow. Thus, whether, the clutch is rotating or not, hydraulic pressure is maintained in the balance chamber and proper clutch operation is assured.
Abstract:
A clutch assembly and method of operating the clutch assembly to start an engine of a hybrid vehicle includes a first clutch and a first clutch actuator for selectively engaging the first clutch. The first actuator has a first at-rest position engaging the clutch and a hydraulically charged position disengaged from the first clutch. The clutch assembly further includes a second clutch actuator having a second at-rest position away disengaged from the first clutch and a second hydraulically charged position engaged with the first clutch.
Abstract:
A detection scheme for diagnosing failure of clutch control components in a hydraulic control module of a power transmission utilizes pressure switch sensors to detect the position of each of the valves associated with the clutch control mechanization. The mechanization of these sensors with the valves provides the ability to clearly define the position of each of the valves, while also enabling the transmission electro-hydraulic control module (TEHCM) to diagnose the state of health of each pressure switch. The detection scheme may then differentiate between a failed switch and a failed (e.g., “stuck” or “out of position”) valve, while preventing unexpected and undesired shift sequencing within the transmission.
Abstract:
A transmission includes two blocking valves that control fluid pressure to a plurality of clutches. The blocking valves are characterized by a plurality of states that result in at least three transmission operating conditions. Each of the three operating conditions is characterized by fluid pressure being unavailable to a respective one of the plurality of clutches.
Abstract:
A hydraulic control system for distributing pressurized fluid to a multi-mode hybrid-type power transmission is provided, as well as a method for regulating the same. The hydraulic control system includes an engine-driven main pump in fluid communication with a main regulator valve, and an electrically-driven auxiliary pump in fluid communication with an auxiliary regulator valve. One pressure control solenoid provides feedback (boost) pressure to both regulator valves, and thereby modify output of the main and auxiliary pumps. A controller selectively modifies distribution of boost pressure to ensure a continuous and controllable feed of hydraulic pressure to the transmission during all vehicle operations. The method includes: determining if the vehicle is transitioning to engine auto-start or auto-stop; determining the line pressure requirements of the transmission under current operating conditions; starting the oncoming-pump; adjusting PCS command so started oncoming-pump pressure equals line pressure requirements; and shutting down off-going-pump.
Abstract:
The normal control of an electrically-activated hydraulic valve armature is overridden to automatically and periodically open the armature for flushing out debris that has accumulated between the armature and a seat that the armature is designed to engage. The valve develops fluid pressure for maintaining engagement of a motor vehicle transmission clutch, and when excessive slippage of the clutch is detected, the armature is forced into engagement with the seat until the slippage is reduced or a predetermined period of time has elapsed, after which the armature is temporarily positioned away from the seat to provide full flow of hydraulic fluid across the seat to flush out debris that prevents the armature from engaging the seat. During Neutral operation of the transmission, the armature is continuously positioned away from the seat, and during low torque conditions the armature is temporarily positioned away from the seat.
Abstract:
An electrosurgical wand. At least some of the illustrative embodiments are electrosurgical wands including an elongate shaft that defines a handle end and a distal end, a first discharge aperture on the distal end of the elongate shaft, a first active electrode of conductive material disposed on the distal end of the elongate shaft, the first active electrode has an edge feature, a first return electrode of conductive material disposed a substantially constant distance from the first active electrode, and an aspiration aperture on the distal end of the elongate shaft fluidly coupled to a second fluid conduit.
Abstract:
Substrates prone to heat distortion may be coated with a coating composition containing chlorinated polyolefin-modified acrylic latex emulsion, polyurethane dispersion, non-gelling self-crosslinking acrylic emulsion, and glycol-based solvent. The coating composition contains sufficient non-gelling self-crosslinking acrylic emulsion and glycol-based solvent so that a 0.1 mm wet thickness layer of the coating composition will form a tack-free film when heated at 65° C. for fifteen minutes, and the glycol-based solvent is selected so that the coating composition is shelf stable.
Abstract:
A fluid is supplied to a housing of a hybrid transmission. An overall system line pressure is elevated to induce leakage of the fluid through a control system. The leaked fluid is flowed through at least one backfill passage to the housing of the hybrid transmission. The leaked fluid is flowed over the motors disposed within the housing to cool the motors. The fluid that is flowed over the motors is collected to create a head pressure within the housing. The head pressure forces the collected fluid upwards within the transmission housing and into clutches that are disposed therein.