A linear actuator for driving an actuating member of an internal combustion engine of a motor vehicle, the linear actuator having two rolling bearings for scanning mutually opposing sides of a rib that is formed as a guide curve. The rib has a variable width, against which the two sensing bodies are biased to reduce or eliminate undesired reaction forces.

A linear actuator for driving an actuating member of an internal combustion engine of a motor vehicle, the linear actuator having two rolling bearings for scanning mutually opposing sides of a rib that is formed as a guide curve. The rib has a variable width, against which the two sensing bodies are biased to reduce or eliminate undesired reaction forces.

Methods and systems are provided for determining whether an exhaust gas recirculation (EGR) valve is degraded and being held open in a vehicle system. In one example, a method may include, in response to an engine pull-down request, closing a throttle coupled to an intake manifold of the engine, closing the EGR valve, propelling the vehicle via an electric motor, and checking operation of the EGR valve based on both intake manifold pressure and exhaust pressure. For example, if the intake manifold pressure does not decrease by a threshold amount relative to the exhaust pressure, EGR valve degradation may be indicated.

Methods and systems are provided for determining whether an exhaust gas recirculation (EGR) valve is degraded and being held open in a vehicle system. In one example, a method may include, in response to an engine pull-down request, closing a throttle coupled to an intake manifold of the engine, closing the EGR valve, propelling the vehicle via an electric motor, and checking operation of the EGR valve based on both intake manifold pressure and exhaust pressure. For example, if the intake manifold pressure does not decrease by a threshold amount relative to the exhaust pressure, EGR valve degradation may be indicated.

A gear assembly rotates about a pin in an actuator. The gear assembly includes a gear. The gear includes a gear body including a first polymer surrounding and extending radially away from a rotational axis. The gear body has an internal surface that defines a bore along and about the rotational axis. The gear further includes a plurality of teeth extending from the gear body. The gear assembly further includes a bushing including a second polymer, different than the first polymer. The bushing is disposed within the bore. One of the bushing and the gear body is overmolded to the other one of the bushing and the gear body along the internal surface. The bushing has a bearing surface defining a hole along and about the rotational axis for rotatably engaging the bearing surface with the pin in the hole.

In a control system for an internal combustion engine, a control unit controls a throttle valve provided in an intake pipe and/or an on-off valve provided in an exhaust gas recirculation pipe when an ignition switch is turned on, in such a manner that an opening degree of the throttle valve and/or an opening degree of the on-off valve is made to be larger than that of a condition before the ignition switch is turned on. In the above Ig-on control, in which the throttle valve and/or the on-off valve is largely opened, a piston is reciprocated in order that gas in a combustion chamber is discharged to an outside of the combustion chamber.

A variable exhaust valve assembly for a vehicle includes an exhaust housing, a power transmission device that transmits rotational power, a shaft that extends through the exhaust housing and is coupled with a valve so as to open and close the exhaust housing, and a heat shielding unit to reduce heat transfer between the power transmission device and the exhaust housing. The power transmission device is configured to regulate an opening degree of the valve. The variable exhaust valve assembly is improved in durability by minimizing damage to power transmission caused by high-temperature heat of exhaust gas, and reducing vibration transmitted to the power transmission device.

A coupling device (32) provides a rotary coupling of a pivot shaft (18) of a flap diaphragm (16) of an exhaust gas flap (10) with a drive element (34). The pivot shaft is to be rotated about a pivot axis (A). The coupling device (32) includes a first coupling part (36) with a first coupling area configured for coupling with the pivot shaft (18) and a second coupling part (38) with a second coupling area configured for coupling with the drive element (34). The first coupling part (36) and the second coupling part (38) are in a rotary coupling positive-locking meshing state with one another in the coupled state and are supported on one another in the direction of the pivot axis (A).

An engine system includes a throttle device, an EGR valve, and an ECU. The ECU diagnoses foreign-matter lodging abnormality of the EGR valve and the foreign-matter diameter based on intake pressure. When the existence of the abnormality and the foreign-matter diameter are determined, the ECU calculates a difference between a foreign-matter diameter and a predetermined learning determination value as a foreign-matter diameter difference. If this difference is larger than an abnormality determination value, the foreign-matter diameter is judged to be excessive and the throttle device is controlled to avoid engine stall. If the foreign-matter diameter difference is equal to or larger than a normality determination value and also equal to or less than the abnormality determination value, engine deceleration is continued. If the foreign-matter diameter difference is less than the normality determination value, the foreign-matter diameter is judged to be minute and the learning determination value is updated.

An engine system includes an injector, an EGR device (including an EGR valve having a step motor) to recirculate part of exhaust gas of an engine as EGR gas to the engine, and an electronic control unit (ECU) to control the injector, the EGR valve, and others based on an operating state of the engine. The ECU is configured to diagnose foreign-matter lodging abnormality of the EGR valve and a lodged foreign-matter diameter based on detected intake pressure during engine deceleration. When existence of the abnormality and the foreign-matter diameter are determined, the ECU controls the step motor to hold the EGR valve at a first opening degree smaller than a second opening degree needed to remove a foreign matter before fuel cut to the engine by the injector.