Abstract: A controllable mechanical seal for sealing a rotating body relative to a housing of a fluid device. The mechanical seal includes a pair of seal rings supported in juxtaposed relation in said housing. Each seal ring has a cylindrical outer surface and a radial end sealing face which, at a given operating condition of the machine, has a predetermined optimum convergence angle relative to the other seal ring face. The sealing faces are yieldably biased into contact with one another to define a dynamic seal there between. A seal ring support member is telescopically arranged about the outer cylindrical surface of one of said ring such that exposed surface area end regions of the cylindrical surface of the support ring are subjected to selectable differential pressures which cause the associated seal ring to distort thereby causing the seal face of the associated ring to assume a select angle of convergence relative to the seal face of the other seal ring.

Abstract: A mechanical seal assembly disposed within a pump housing for retarding the flow and leakage of fluids and other matter from being pumped along the motor drive shaft. The mechanical seal assembly of the present invention includes a non-rotating seal ring and a seal ring which rotates with the motor drive shaft. The non-rotating seal ring is resiliently mounted from the impeller side of the housing and is operably carried by the pump housing such that its seal face is urged toward the seal face of the rotating seal ring. A flexible assemblage comprises part of the non-rotating seal mounting arrangements and assures flexibility of the non-rotating seal face despite pump operating conditions.

Abstract: An adaptive control system regulates operation of a mechanical seal assembly by reacting dynamically to changes in seal operating conditions to provide minimal wear with minimal fluid leakage. The disclosed "self-learning" method adapts automatically to arbitrary changes in fluid medium temperature and pressure, as well as shaft rotation speed, by detecting a limit cycle type oscillation of a seal-related variable, such as temperature of a seal face and/or fluid temperature. This variable is monitored via a microcomputer-based system which identifies these abrupt oscillations or spikes. The control algorithm selects a particular displacement of an actuator to modify the seal face deflection to the optimal value, and in this way attains maximum seal life while minimizing leakage.

Abstract: A mechanical seal assembly for use with centrifugal pumps including at least one unitized elastomer assembly for urging the seal faces of a pair of seal rings into sealing engagement with each other. The unitized elastomer assembly serves as a seal ring mounting arrangement and includes a spaced pair of metallic rings which are chemically bonded to an annular elastomer body disposed therebetween and whose cross section between the rings is loaded in shear when the elastomer assembly is operatively arranged in the pump. A mechanical seal is established between at least one of said rings and the elastomer body for protecting the chemical bond therebetween against attack by corrosive pump product.

Abstract: A controllable mechanical seal for sealing a shaft rotatable relative to the housing of a fluid machine includes first and second face elements having first and second radial surfaces. The first element is adapted for rotation with the shaft. The second element is adapted to be stationary within the housing. One of the elements is movable axially relative to the shaft. The first and second surfaces are adapted to define a gap within which there is a thin lubricating fluid film. An actuator is provided for deforming at least one of the surfaces so that the gap converges in a direction from a high pressure side to a low pressure side of the seal. A sensor is provided for measuring a temperature indicative of incipient contact of said surfaces. A control system responsive to the sensor generates an external voltage which is applied to the actuator to control the convergence of the surfaces and thus maintain an optimum thickness of the lubricating film for a wide range of operating conditions.