Rotary piston pump having a sealing chamber seal

A rotary piston pump, comprising:

• a pump chamber having a pump chamber inlet opening and a pump chamber outlet opening;
• two mutually meshing rotary pistons which are fastened on two pump shafts that correspondingly run so as to be mutually parallel and which in a mutually opposing rotation convey a pump-conveyed fluid from the pump chamber inlet opening to the pump chamber outlet opening;
• a drive mechanism which for driving the rotary pistons is coupled to at least one of the two pump shafts;
• and
• a seal assembly comprising a blocking chamber disposed adjacent the pump chamber of the rotary piston pump, the blocking chamber being sealed in relation to the pump chamber by a first shaft seal that encloses a first of the two pump shafts and a second shaft seal that encloses a second of the two pump shafts;
• wherein the blocking chamber is pressurized with a fluid pressure resulting from a fluid pressure differential generated by the sealing-fluid pump device, whereby said fluid pressure interacts with the first shaft seal and the second shaft seal to seal the pump chamber in relation to the egress of pump-conveyed fluid from the pump chamber along the pump shafts, such that said blocking chamber provides a seal between the drive mechanism and the pump chamber;
• and
• wherein the sealing-fluid pump device, when exceeding a predetermined fluid pressure in the blocking chamber, is configured for releasing a passage of a sealing fluid from a sealing-fluid pump device outlet to a sealing-fluid pump inlet and for opening an egress of the sealing fluid from the blocking chamber through the sealing-fluid pump device.

A seal cartridge for a seal assembly for sealing a pump shaft in a rotary piston pump configured for conveying pump-conveyed fluid, the seal assembly comprising:

• a sealing-fluid pump device having a pump inlet and a pump outlet;
• and
• a blocking chamber connected to the pump outlet and disposed so as to neighbor a pump chamber of the rotary piston pump, the blocking chamber being sealed in relation to the pump chamber by a first shaft seal that encloses the pump shaft;
• wherein the blocking chamber is pressurized with a fluid pressure resulting from a fluid pressure differential generated by the sealing-fluid pump device, whereby said fluid pressure interacts with the first shaft seal to seal the pump chamber in relation to the egress of pump-conveyed fluid from the pump chamber along the pump shaft;
• and
• wherein the seal cartridge comprises:
• the first shaft seal having an internal circumferential face surrounding a passage opening for the pump shaft and configured for the sealed disposal in the manner of a relative movement about the pump shaft;
• a second shaft seal having an internal circumferential face surrounding a passage opening for the pump shaft and configured for the sealed disposal in the manner of a relative movement about the pump shaft;
• and
• an activation element disposed between the first shaft seal and the second shaft seal and coupled in a torque-locking manner to the pump shaft, and having an activation face for the sealing-fluid pump device.

A seal assembly for sealing a pump shaft in a rotary piston pump configured for conveying pump-conveyed fluid, comprising:

• a sealing-fluid pump device having a pump inlet and a pump outlet;
• a blocking chamber connected to the pump outlet and disposed so as to neighbor a pump chamber of the rotary piston pump, the blocking chamber being sealed in relation to the pump chamber by a first shaft seal that encloses the pump shaft;
• an eccentric element having an encircling eccentric circumferential face that is eccentric in relation to a rotation axis of the eccentric element and configured for a torque-locking connection to the pump shaft of the rotary piston pump that leads out of the pump chamber of the rotary piston pump;
• and
• a pump unit which is coupled to the eccentric element and upon rotation of the eccentric element generates a fluid pressure differential in a sealing fluid between the pump inlet and the pump outlet;
• wherein the blocking chamber by way of the pump outlet of the sealing-fluid pump device is impinged with a fluid pressure resulting from the fluid pressure differential generated by the sealing-fluid pump device, whereby said fluid pressure interacts with the first shaft seal to seal the pump chamber in relation to the egress of pump-conveyed fluid from the pump chamber along the pump shaft.

A seal assembly for sealing a pump shaft in a rotary piston pump configured for conveying pump-conveyed fluid, comprising:

• a sealing-fluid pump device having a pump inlet and a pump outlet;
• a blocking chamber connected to the pump outlet and disposed so as to neighbor a pump chamber of the rotary piston pump, the blocking chamber being sealed in relation to the pump chamber by a first shaft seal that encloses the pump shaft;
• and
• a control unit for controlling a fluid pressure in the blocking chamber;
• wherein the blocking chamber by way of the pump outlet of the sealing-fluid pump device is impinged with the fluid pressure resulting from a fluid pressure differential generated by the sealing-fluid pump device, whereby said fluid pressure interacts with the first shaft seal to seal the pump chamber in relation to the egress of pump-conveyed fluid from the pump chamber along the pump shaft;
• and
• wherein the control unit is configured for increasing the fluid pressure in the blocking chamber in response to a predetermined pressure in the pump chamber for a predetermined temporal period at predetermined temporal intervals or in predetermined operating states.

A seal assembly for sealing a pump shaft in a rotary piston pump configured for conveying pump-conveyed fluid, comprising:

• a sealing-fluid pump device having a pump inlet and a pump outlet;
• a blocking chamber connected to the pump outlet and disposed so as to neighbor a pump chamber of the rotary piston pump, the blocking chamber being sealed in relation to the pump chamber by a first shaft seal that encloses the pump shaft;
• a control unit for controlling a fluid pressure in the blocking chamber;
• and
• a leakage sensor for detecting a leakage from the blocking chamber;
• wherein the blocking chamber by way of the pump outlet of the sealing-fluid pump device is impinged with the fluid pressure resulting from a fluid pressure differential generated by the sealing-fluid pump device, whereby said fluid pressure interacts with the first shaft seal to seal the pump chamber in relation to the egress of pump-conveyed fluid from the pump chamber along the pump shaft;
• and
• wherein the control unit is in signal communication with the leakage sensor and, as a function of the sensor signal of the leakage sensor, initiates the fluid pressure in the blocking chamber by increasing the fluid pressure in the blocking chamber in the event of a leakage below a predetermined lower leakage limit value, or reducing the fluid pressure in the blocking chamber in the event of a leakage above a predetermined leakage limit value.