Abstract: A method for controlling a hydraulic flow within a powertrain comprising an electromechanical transmission mechanically-operatively coupled to an engine adapted to selectively transmit power to an output, wherein the transmission utilizes a hydraulic control system serving a number of hydraulic oil consuming functions includes monitoring minimum hydraulic pressure requirements for each of the functions, determining a requested hydraulic pressure based upon the monitoring minimum hydraulic pressure requirements and physical limits of the hydraulic control system including a maximum pressure, determining a desired flow utilizing a hydraulic control system flow model based upon the requested hydraulic pressure, and utilizing the desired flow to control an auxiliary hydraulic pump.

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 servo valve for shifting a transmission between a park and out of park position includes a valve housing and a park servo. A first and second solenoid is disposed in the valve housing for transmitting a respective first or second signal to shift the transmission to the respective first or second state of operation. The park servo is fluidly connected to the transmission and is responsive to the first and second signals to shift the transmission to the respective positions. Fluid pressure within the valve housing moves a valve member therein to move a piston within the park servo to shift the transmission to the corresponding position. A third solenoid transmits a third signal in combination with the second signal to latch and hold the valve member in the corresponding position.

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 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.

Abstract: An electrically variable transmission (EVT) selectively establishes various EVT modes and a neutral mode. The EVT includes a source of pressurized fluid, fluid-actuated clutches, various solenoid-actuated valves including trim valves and blocking valves adapted to control a flow of pressurized fluid to the clutches to establish the transmission operating modes, and an electronic control unit (ECU). The ECU actuates different combinations of the solenoid-actuated valves to establish the different transmission modes. The solenoid-actuated valves are configured in such a manner as to provide the EVT with one or more default operating modes in the event the ECU temporarily loses electrical power. Depending on the particular configuration, the default modes can be the neutral mode alone, or the neutral mode combined with one or more of the EVT modes, with the EVT modes enabled by providing one or both of the blocking valves with a latching feature.

Abstract: A hydraulic control system for a multi-mode hybrid-type power transmission is provided, including 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. A first pressure control solenoid is configured to provide boost pressure to the main regulator valve and thereby boost output of the main pump. A second pressure control solenoid is configured to provide boost pressure to the auxiliary regulator valve and thereby boost output of the auxiliary pump. The distribution of boost pressure from the pressure control solenoids is selectively modified such that at least one of the flows of pressurized fluid from the pumps is equal to the current line pressure requirements of the transmission during engine auto-start and auto-stop, and transitions thereto. An improved method for regulating the hydraulic control system is also provided.

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 at least one of the clutches.

Abstract: A method for controlling cooling of one or more motor/generators includes monitoring the stator temperature of the motor/generator and power loss of the motor/generator. Total cooling flow is estimated from the monitored stator temperature and power loss and a cooling line pressure is determined from a lookup table. The lookup table includes total cooling flow as a function of cooling line pressure. The method further determines a non-cooling line pressure and combines the non-cooling line pressure with the cooling line pressure to determine a first total line pressure. The transmission is commanded to operate at the first total line pressure.

Abstract: A transmission includes first and second clutch members rotatable about the same axis. An axial groove is formed in one of the members to distribute lubricating fluid to the other member. Preferably, clutch plates with radial grooves extend between the clutch members. Fluid flows from the axial groove through the radial groove and across faces of the clutch plates to separate the plates during disengagement in order to minimize spin losses.

Abstract: An assembly and method is provided for reducing clutch wear due to centrifugal apply pressure within a clutch-apply cavity. The assembly comprises a rotatable clutch housing, a clutch-apply piston disposed within a clutch-apply cavity, and a balance piston. The balance and apply pistons define a balance cavity including a liquid fill channel and a dedicated air exhaust channel having a control radius configured to at least partially offset or compensate for the centrifugal apply force generated within the clutch-apply cavity when the clutch assembly rotates. The method includes configuring the balance cavity with an exhaust channel for exhausting fluid, and providing the exhaust channel with a control radius determined by the innermost radius of rotating fluid within the balance cavity as measured with respect to the centerline of rotation of the clutch assembly, the control radius being suitable for exhausting any excess of centrifugal balance force over centrifugal apply force.

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 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: An electrically variable transmission (EVT) selectively establishes various EVT modes and a neutral mode. The EVT includes a source of pressurized fluid, fluid-actuated clutches, various solenoid-actuated valves including trim valves and blocking valves adapted to control a flow of pressurized fluid to the clutches to establish the transmission operating modes, and an electronic control unit (ECU). The ECU actuates different combinations of the solenoid-actuated valves to establish the different transmission modes. The solenoid-actuated valves are configured in such a manner as to provide the EVT with one or more default operating modes in the event the ECU temporarily loses electrical power. Depending on the particular configuration, the default modes can be the neutral mode alone, or the neutral mode combined with one or more of the EVT modes, with the EVT modes enabled by providing one or both of the blocking valves with a latching feature.

Abstract: An access assembly for use during a medical procedure including accessing a selected bone structure or target tissue, includes a cannula and stylet with an alignment guide removably attached to the cannula. The alignment guide shows the relative alignment between the access assembly and the viewing axis of an imaging system, thereby making placement of the access assembly more accurate. Once a desired alignment is achieved, the access assembly may then be advanced further towards the target tissue until a desired placement is achieved.

Abstract: A servo valve for shifting a transmission between a park and out of park position includes a valve housing and a park servo. A first and second solenoid is disposed in the valve housing for transmitting a respective first or second signal to shift the transmission to the respective first or second state of operation. The park servo is fluidly connected to the transmission and is responsive to the first and second signals to shift the transmission to the respective positions. Fluid pressure within the valve housing moves a valve member therein to move a piston within the park servo to shift the transmission to the corresponding position. A third solenoid transmits a third signal in combination with the second signal to latch and hold the valve member in the corresponding position.

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 at least one of the clutches.

Abstract: The present invention provides advanced hardware diagnostic detection for the clutch control components in a hydraulic control module of a multi-mode hybrid transmission. The detection scheme of the present invention 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. This will allow the diagnostics to differentiate between a failed switch and a failed (e.g., “stuck” or “out of position”) valve. The present invention offers the ability to safely diagnose the clutch control components in a power transmission, while preventing unexpected and undesired shift sequencing within the transmission.

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.

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.