Patent ID: 8967125
Filing Date: 2015-03-03
Classification: F02M,F16K

Abstract:
1. An EGR valve comprising: a housing having a passage for EGR gas; a valve seat provided in the passage; a valve element being seatable on the valve seat; a valve shaft integrally provided with the valve element to move the valve element with respect to the valve seat; a drive unit for causing the valve shaft together with the valve element to perform a stroke movement in an axial direction; a bearing placed between the housing and the valve shaft to support the valve shaft to allow the stroke movement, the bearing having a first end and a second end in an axial direction; a seal member placed between the housing and the valve shaft and adjacent to the bearing to seal between the housing and the valve shaft, the seal member having a first end and a second end in an axial direction and a seal portion including a leading end on the second end side, the leading end being in contact with the valve shaft; a deposit-guard member placed between the housing and the valve shaft and adjacent to the seal member to protect between the housing and the valve shaft from deposits, the deposit-guard member having a first end and a second end in an axial direction; and the first end of the seal member being placed adjacent to the first end of the bearing, the first end of the deposit-guard member being placed adjacent to the second end of the seal portion of the seal member, and the second end of the deposit-guard member being placed to face the passage, wherein: the deposit-guard member is inserted on the valve shaft with a clearance from the valve shaft; and when a distance from the first end of the bearing adjacent to the first end of the seal member to the leading end of the seal portion of the seal member is referred to as a first distance and a distance from the second end of the deposit-guard member facing to the passage to the leading end of the seal portion of the seal member is referred to as a second distance, the first distance and the second distance are set to be longer than a maximum stroke of the stroke movement of the valve shaft.