The invention relates to a dry-compressing or oil-free compressor for generating a compressed gas and a method for oil separation for a dry-compressing compressor (1). The compressor has a compressor housing (4), a compression chamber (5) and at least one oil chamber (19a, 19b), in which an oil-lubricated bearing (18a, 18b) of the rotor bearing (16) is accommodated, as well as a shaft seal arrangement (10a, 10b), which is arranged between the oil-lubricated bearing (18a, 18b) and the compression chamber (5). The shaft seal arrangement (10a, 10b) has an outer seal (17a, 17b) facing the oil-lubricated bearing (18a, 18b) and an inner seal (12a, 12b) facing the compression chamber (5), wherein at least one sealing gas chamber (13a, 13b, 13c, 13d) for receiving sealing gas is formed between the outer seal (17a, 17b) and the inner seal (12a, 12b). The oil chamber (19a, 19b) has at least one gas inlet for a sealing gas flow from the sealing gas chamber (13a, 13b, 13c, 13d) and a gas outlet (26) for connection to an oil separator (30, 31, 32, 33). The oil chamber (19a, 19b) provides an oil chamber pressure p.sub.OR that exceeds the ambient pressure p.sub.0 of the compressor housing (4) by an oil separation pressure difference ?p.

The invention relates to a dry-compressing or oil-free compressor for generating a compressed gas and a method for oil separation for a dry-compressing compressor (1). The compressor has a compressor housing (4), a compression chamber (5) and at least one oil chamber (19a, 19b), in which an oil-lubricated bearing (18a, 18b) of the rotor bearing (16) is accommodated, as well as a shaft seal arrangement (10a, 10b), which is arranged between the oil-lubricated bearing (18a, 18b) and the compression chamber (5). The shaft seal arrangement (10a, 10b) has an outer seal (17a, 17b) facing the oil-lubricated bearing (18a, 18b) and an inner seal (12a, 12b) facing the compression chamber (5), wherein at least one sealing gas chamber (13a, 13b, 13c, 13d) for receiving sealing gas is formed between the outer seal (17a, 17b) and the inner seal (12a, 12b). The oil chamber (19a, 19b) has at least one gas inlet for a sealing gas flow from the sealing gas chamber (13a, 13b, 13c, 13d) and a gas outlet (26) for connection to an oil separator (30, 31, 32, 33). The oil chamber (19a, 19b) provides an oil chamber pressure p.sub.OR that exceeds the ambient pressure p.sub.0 of the compressor housing (4) by an oil separation pressure difference ?p.

An oil flooded screw compressor includes a housing with an inlet and an outlet, and a rotor supported within the housing by a bearing. The rotor is rotatable to compress air from the inlet to the outlet when the compressor is in an operating state, and the rotor is rotatable without compressing air when the compressor is in an idle state. The compressor also includes a pump configured to supply oil to the bearing only when the compressor is in the idle state.

An oil flooded screw compressor includes a housing with an inlet and an outlet, and a rotor supported within the housing by a bearing. The rotor is rotatable to compress air from the inlet to the outlet when the compressor is in an operating state, and the rotor is rotatable without compressing air when the compressor is in an idle state. The compressor also includes a pump configured to supply oil to the bearing only when the compressor is in the idle state.

An oil-free screw compressor with good assemblability of a shaft seal device that reduces leakage of a compressed gas, where the oil-free screw compressor accommodates male and female screw rotors in a rotor chamber of a casing, supports each screw rotor by a bearing through a rotor shaft, and has shaft seal devices in a shaft seal space. The shaft seal devices include an oil seal on the side of the bearing, a packing case on the side of the rotor chamber, and a gas seal. An end of the packing case on the side of the bearing and an end of the oil seal on the side of the rotor chamber are fitted and fixed by interference fit to form a gas seal accommodation space, the gas seal accommodation space accommodating the seal ring.

An oil-free screw compressor with good assemblability of a shaft seal device that reduces leakage of a compressed gas, where the oil-free screw compressor accommodates male and female screw rotors in a rotor chamber of a casing, supports each screw rotor by a bearing through a rotor shaft, and has shaft seal devices in a shaft seal space. The shaft seal devices include an oil seal on the side of the bearing, a packing case on the side of the rotor chamber, and a gas seal. An end of the packing case on the side of the bearing and an end of the oil seal on the side of the rotor chamber are fitted and fixed by interference fit to form a gas seal accommodation space, the gas seal accommodation space accommodating the seal ring.

A lubricant recovery system for vacuum pump comprising a reservoir to store lubricant. Supply lines connected to the reservoir wherein the supply line can be connected to the vacuum pump to supply the lubricant to the vacuum pump. Further, a return line is connected to the reservoir to return a lubricant-air mixture from the vacuum pump to the reservoir by the return line. An air filter is disposed inside the reservoir to separate lubricant from the air wherein the filter is connected to a scavenge line which is connectable to a low-pressure region of the vacuum pump such that lubricant separated from the lubricant-air mixture by the air filter is drawn via the scavenge line into the vacuum pump. In accordance to the present invention a valve is disposed in the scavenge line to selectively separate the air filter from the vacuum pump.

A lubricant recovery system for vacuum pump comprising a reservoir to store lubricant. Supply lines connected to the reservoir wherein the supply line can be connected to the vacuum pump to supply the lubricant to the vacuum pump. Further, a return line is connected to the reservoir to return a lubricant-air mixture from the vacuum pump to the reservoir by the return line. An air filter is disposed inside the reservoir to separate lubricant from the air wherein the filter is connected to a scavenge line which is connectable to a low-pressure region of the vacuum pump such that lubricant separated from the lubricant-air mixture by the air filter is drawn via the scavenge line into the vacuum pump. In accordance to the present invention a valve is disposed in the scavenge line to selectively separate the air filter from the vacuum pump.

The invention relates to a sealing arrangement (1) for conveying devices, in particular for gear pumps, in which an inner space (5) can be sealed off from an outer space (6), wherein the sealing arrangement comprises at least two parts (2, 3) each having at least one sealing surface (20, 21), wherein the sealing surfaces (20, 21) comprise: a first seal (11) along a first, medial perimeter of the sealing surface (20, 21), a second seal (12) along a second, lateral perimeter of the sealing surface (20, 21), a recess (15) between the first seal (11) and the second seal (12), characterized in that the recess (15) can be connected to a source (30) of a flushing medium such that the recess (15) can be actively flushed with the flushing medium.

A liquid ring screw pump includes a housing with a suction inlet section and a pressure outlet section. Within the housing an Archimedes screw rotor is driven by a motor via a shaft. The inlet section and outlet section are each provided with connecting structure for suction and pressure piping respectively. The displacement CD of the screw rotor in relation to the center axis of the housing is determined by an equation based on the screw rotor radius, a minimum screw rotor core radius, and a variable k that is between 0.14 and 0.29.