Abstract: A packet scheduling method and apparatus including (a) classifying a stream that enters into a scheduler according to a data rate and/or length of a packet; (b) if the packet of the classified stream is a first packet, storing the packet in a first stream queue, and if the packet of the classified stream is a subsequent packet, storing the packet in a second stream queue; (c) counting a virtual start service time of the packet stored in the first stream queue according to a weighted fairness queuing method; and (d) counting a virtual start service time of the packet stored in the second stream queue as a virtual start service time of the previous packet.

Abstract: A bi-direction rotatable face seal with spiral grooves is provided comprising: a rotating ring with a sealing face sealed and fixed on a rotary shaft; a stationary ring with a sealing face mounted in a casing, which is sealed and axially aligned by means of an elastomeric O-ring, a thrust ring, springs and anti-rotating pins; the sealing face of the stationary ring is pushed into engagement with the sealing face of the rotating ring to form a sealing interface; sealing fluid is located on high pressure side of the sealing interface; the rotating ring can rotate relative to the stationary ring in bi-direction without contact.

Abstract: A bi-direction rotatable face seal with spiral grooves is provided comprising: a rotating ring with a sealing face sealed and fixed on a rotary shaft; a stationary ring with a sealing face mounted in a casing, which is sealed and axially aligned by means of an elastomeric O-ring, a thrust ring, springs and anti-rotating pins; the sealing face of the stationary ring is pushed into engagement with the sealing face of the rotating ring to form a sealing interface; sealing fluid is located on high pressure side of the sealing interface; the rotating ring can rotate relative to the stationary ring in bi-direction without contact.

Abstract: The present invention provides a face seal with spiral grooves comprising: a rotating ring including a sealing face; a stationary ring including a sealing face; the face is confronted with the face of the rotating ring to form a circular interface having a circle center; the faces of the rings can rotate relatively to each other; two spiral groove sets are provided at least on one of the faces of the rotating and the stationary rings, wherein one set disposed on the high pressure side, i.e. at the upstream, and the other set disposed on the low pressure side, i.e. at the downstream; the spiral angles of these two spiral groove sets are opposite to each other; the radial length of an upstream spiral groove is greater than that of a downstream spiral groove; and an annular flat belt is further provided at the downstream of the downstream spiral groove set.