The mechanical seal device comprises a rotating unit (11) and a stationary unit (12) respectively comprising a ring of ceramic material (13, 15) associated with the bottom of a support element (14, 16) of polymeric material shaping a respective sealing face. The rotating unit (11) and the stationary unit (12) are suitable to be coaxially mounted on a shaft (8) of a rotating member (3), in specular position, so that said rings (13, 15) of ceramic material have said seal faces in mutual contact on a plane substantially perpendicular to the axis of the shaft (8).

Provided is a mechanical seal that eliminates the need to provide an additional bearing, enables size reduction and cost reduction, and can provide stable performance as a bearing. A stationary-side seal ring 20 is disposed on the high-pressure fluid side of a rotating-side seal ring 21, and fixed to a housing 1 and has sliding surfaces 20a, 20c, and 20d supporting a rotating shaft 2 in both a radial direction and a thrust direction. The rotating-side seal ring 21 is axially movably fitted by an urging means 25 fitted on the rotating shaft 2. The rotating shaft 2 has an outer peripheral surface 2a a contacting and sliding on the radial sliding surface 20a of the stationary-side seal ring 20 to be supported radially. Thrust rings 10a and 10b are provided between the stationary-side seal ring 20 and the rotating shaft 2, for supporting the rotating shaft 2 in thrust directions.

A mechanical seal assembly has two axially-spaced apart seals and including a rotary component that includes rotational members of each axially-spaced apart seal and a stationary component that includes stationary sealing members of each seal. A sleeve is located radially inwards of the rotational sealing members. An element, such as fluid ports, directs barrier or buffer fluid towards the sleeve and between the two axially-spaced apart seals. The sleeve is provided on its outer surface with means, such as recesses or protuberances, which displace barrier/buffer fluid axially towards both axially-spaced apart seals.

A mechanical sealing device includes rotating and stationary rings, and rotating and stationary ring adaptors mounted around a rotating shaft. An end surface of the rotating ring adjoins an end surface of the stationary ring by means of springs. The sealing interface includes an adjoining point that is in contact with a liquid medium in an axial section of the device, and an annular peripheral rim surrounding the rotating and stationary rings for agitating the liquid medium. At least a part of the peripheral rim is formed with an inclined surface oriented toward the adjoining point, the inclined surface defining a start point close to the adjoining point and an end point away from the adjoining point in the axial section of the device. The start point is spaced apart from the adjoining point while the end point extends not beyond the adjoining point in the axial direction.

A seal arrangement includes a first and a second machine part which are arranged spaced apart from one another with the formation of a sealing gap and can be moved relative to one another about a movement axis. A seal element with a base section is arranged on or in a seal holding structure of one of the two machine parts. A sealing head bears in a dynamically sealing manner by way of a sealing section against a sealing surface of the respective other machine part in order to seal a high-pressure side from a low-pressure side. The seal element on the high-pressure side has at least one flow element, wherein during relative movement of the two machine parts fluid on the high-pressure side in the area of the sealing section of flows onto the sealing head.

A sealing system includes: a double mechanical seal having a pump-side sealing mechanism (10, 12) and an atmospheric-side sealing mechanism (11, 13); a pump mechanism (19) driven by a rotational shaft (1); a first medium circulation line (30) for circulating a fluid barrier-and-cooling medium between a first chamber (22a) and a second chamber (22b), the first medium circulation line (30) being coupled to the first chamber (22a) and the second chamber (22b), the fluid barrier-and-cooling medium being different from a fluid handled by the centrifugal pump; a heat exchanger (21) and a shut-off valve (28) attached to the first medium circulation line (30); a second medium circulation line (31) bypassing the shut-off valve (28); and a medium pressurizing pump (45) and an on-off valve (23) attached to the second medium circulation line (31).

A seal includes a mating ring that rotates relative to a carbon primary ring at a seal interface. A buffer gas is provided into the seal and passes from the back of the primary ring to the seal interface. The seal can be used as a separation seal or in combination with another seal.

A shaft sealing arrangement includes a first seal and a second seal, wherein the first seal is designed in the form of a lip seal and the second seal is designed in the form of a mechanical seal. When the shaft is at a standstill, the lip seal performs the sealing action and, when the shaft is rotating, the mechanical seal performs the sealing action.

A seal system for a bearing compartment of a gas turbine engine includes an annular rotating seal seat in contact with the seal element to form a dry seal interface therebetween to separate am oil-wetted zone from a dry zone. The annular rotating seal seat forms a dry zone annular space adjacent to the annular seal element and the rotating component. The annular rotating seal seat having an oil return passageway through the rotating seal seat to provide a communication path from the dry zone annular space outboard of the rotating component back to the oil-wetted zone.

A seal structure of a drive device is provided which includes a case in which a motor chamber for accommodating an electric motor and a gear chamber for accommodating a gear mechanism are located adjacent to each other, a partition that separates the motor chamber and the gear chamber, a bearing that supports a rotating shaft, a seal part that seals between the rotating shaft and the partition, a lubricating oil that lubricates the gear mechanism, and a coolant that cools the electric motor, and also includes a first bearing on the motor chamber side, a second bearing on the gear chamber side, a first seal part on the motor chamber side, a second seal part on the gear chamber side, and at least the second seal part of the first seal part and the second seal part is provided between the first bearing and the second bearing.