Patent ID: 6932348

Claim:
A mechanical seal installed externally of a shaft and a device body through which the shaft passes, comprising: an attachment member detachably attached to an external face of the device body by a gasket disposed therebetween and having an inner face fitted to the shaft; a first seal ring being axially movable relative to the shaft, and fitted to the inner face of the attachment member, the first seal being axially biased by a resilient means and having a seal face at an outer end; a second seal ring having a relative seal face in close contact with the seal face of the first seal ring, wherein the first and second seal rings are disposed outside the external face of the device body and the second seal ring is disposed axially further from the external face of the device body than the first seal ring; and a seal collar being secured to the shaft and retaining with fluid tight the second seal ring; wherein the attachment member includes an annular cooling groove formed to cover circumferentially over the seal face of the first seal ring fitting to the inner surface of the attachment member, wherein a cooling fluid passes through the annular cooling groove and cools the seal face; a throttling face integral to the attachment member is disposed axially outward relative to the annular cooling groove; a throttling gap defined between the outer circumferential surface of the second seal ring and the throttling face, wherein the throttling gap is in open communication with an outer environment; and a diameter of the annular cooling groove is larger than a diameter of the throttling face; the attachment member also includes a coolant passage in communication with the annular cooling groove, wherein the coolant passage communicates with a drain port located under the cooling passage.