Abstract: A rotating flow pump such as a centrifugal pump is provided with a feed pump unit formed as an ejector. The feed pump unit comprises an inlet portion, a nozzle, and a diffuser arranged in succession, and the diffuser is connected to the inlet opening of the flow pump. The inlet portion, the nozzle, and the diffuser of the ejector are situated in a plane perpendicular to the shaft of the flow pump. The diffuser comprises an inner channel of a uniformly increasing flow cross section at least over part of its length. Furthermore the diffuser comprises an outer jacket situated substantially coaxially about the above channel. Thus the jacket is formed in such a manner that a substantially 180.degree. almost mushroom-shaped turning of the flow direction for the liquid flowing through the diffuser is obtained at the same time as a uniformly increasing flow cross section--seen in the flow direction--is obtained within the annular chamber between the channel and the jacket.

Abstract: This invention relates to a pumping assembly for heating and faucet water plants, comprising a wet-armature motor and a centrifugal pump driven thereby, the casing of which is pressed to shape from metal plate and has an axially directed collar against which bears the encircling marginal area of a partition separating the pumping space from the motor space, and which is joined by welding to an equally encircling marginal area of the split tube separating the armature space from the stator space. A particularly uncomplicated and safe joint results between the components in question due to the fact that, in accordance with the invention, the partition and the split tube are interwelded at least at points in their mutual contact area and are, jointly with the armature connected to the pump casing, to form a structural unit ready for installation, by connecting the collar of the pump casing in liquid-tight manner to the said marginal area of the split tube by pressure welding.

Abstract: In the case of a pumping set comprising an electric motor and a rotary pump driven by the same, the r.p.m. may be controlled as a function of selected operating parameters of the set in steps within the area of a characteristic field, the limits of which are determined on the one hand by the two modulating graphs for the maximum and minimum r.p.m. figures and on the other hand by the co-ordinates delivery head and delivery flow. A particular partial span may in each case be determined on the modulating graphs valid for constant r.p.m. figures. An r.p.m. switching action is triggered upon reaching the operating parameters of the set representative for the terminal values of the partial spans, the r.p.m. being lowered if the one terminal value is reached on one partial span with the greater delivery head and the lesser delivery flow, and raised if the other terminal value on the partial span in question is obtained with the lesser delivery head and the greater delivery flow.

Abstract: The invention relates to a pumping set for plants carrying water, comprising a split-tube motor and a rotary pump driven by the same, the impeller of which is located on the extremity of the shaft present in the pumping space, said shaft being carried by two radial anti-friction bearings situated at either side of the rotor stack of laminations, and consists of ceramic material at least in the area of these anti-friction bearings and is longitudinally movable with respect to the ceramic bearing rings of the radial anti-friction bearings under forces acting axially on the impeller, the maximum length of this longitudinal displacement being limited by two axial anti-friction bearings. An annular groove is provided in the shaft directly adjacent to each of the two bearing areas of the radial anti-friction bearings, that is to say in each case adjacent the extremity of these bearing areas directed towards the impeller, and that the said distance is smaller than the width of the annular grooves.

Abstract: The level detector is to be used for starting and stopping an electric system such as a pump. It comprises a piezo-electric crystal (31) squeezingly mounted between two elastically resilient membranes (22, 23) situated between two squeezing members (11, 12). These squeezing members form a top part (11) and a bottom part (12), respectively, which together form a sensor housing (10). On the outside the membranes are coated with a thin, insulating plastic layer (21, 24) and form the electric connection to the crystal. The two membranes are kept separated by means of a plurality of insulating, annular disks (25-28). In this manner a sturdy and reliable mounting of the piezo-electric crystal is obtained.

Abstract: An apparatus for controlling the operation of a pump, especially a submersible pump, and particularly for controlling a water level in connection with cellar drainage pumps, comprises at least one level detector using the principle of acoustic impedance for detecting the presence or absence of liquid to be pumped, said level detector being electrically connected to a control circuit controlling a switching device for the pump.

Abstract: A wet-motor pump having the rotor and the bearings utilize the pumped liquid, whereas the dry stator chamber with the stator windings is separated from and sealed against the rotor chamber through a tube-shaped can. The ends of the winding wires extend freely outwards on one side of the stator stack of sheets such as through an opening in the motor housing to be connectable to electric connections of a connection box mounted on the motor housing. A power cable for supply of energy to the windings is inserted in the connection box. The ends of the windings are connected to winding terminals in the stator chamber. The winding terminals are connectable to contacts and a plug. The plug comprising a shaft surrounding and isolating the contact may be inserted through the opening in the housing and into the stator chamber. As a result, a pump is obtained whereby the electric connections between the ends of the windings and the connections in the connection box may be provided in a simple and quick manner.

Abstract: In a pump comprising a slotted tube motor, the ventilating procedure is carried out by the water entering a rotor chamber and being caused to circulate by means of the rotating rotor in such a manner that a circulating ring of liquid is formed within the rotor chamber, and that the air present in the chamber is pressed towards the axis of rotation of the rotor. The liquid flows from a pump room into the rotor chamber through a bearing slot in a front sliding bearing situated at the impeller of the pump. Liquid from the ring of liquid adjacent the rear sliding bearing is carried into a bearing slot in the rear sliding bearing by way of a connecting duct formed in part in the bearing sleeve. This sliding bearing opposes an air duct closed by a vent plug. The rotor chamber and the air duct are interconnected solely through the bearing slot in the rear sliding bearing.

Abstract: A centrifugal pump for moving gaseous liquids comprises a gas separator situated in the suction chamber of the pump. The outlet of the gas separator is aligned with the inlet of the impeller, the degased liquid passing through said outlet. The separated gas is drained off to the ambiency through a tapped hole in the pump casing, to which a ventilator is connected. The gas separator is mounted in its fitting position after it has been carried from the pressure chamber of the pump and through an opening in a partition between the suction chamber and the pressure chamber and further on into the suction chamber. The gas separator is retained in its fitting position by means of securing means in the positions in which the water and gas outlets of the gas separator are situated. As a result, the pump casing may be manufactured from a simple and relatively small moulding piece. The pump casing need not comprise several parts.

Abstract: A circulating pump unit comprising a pump and a motor for heating and service water installations, in which the motor is settable to at least two different speeds of rotation by means of a rotation speed switch. According to the invention the motor (1) couples automatically and independently of the operational speed (n) set on the rotation speed switch (3), after switching off or switching on of the unit by means of a start-up switch (5) overriding the rotation speed switch to the rotation speed (n3) with maximum start-up moment (M3) and starts at this rotation speed and after a pre-determined time switches over to the operational rotation speed set on the rotation speed switch. Thereby the circulating pump unit will give a reliable start of the pump also after a standstill for a long time.

Abstract: In a device having a gas separation chamber situated between an entry pipe for a gas-containing liquid and an exit pipe for de-gassed liquid wherein a twisting motion is supplied to the gas-containing liquid in the chamber so that gas in the centrifugal field of flow is forced toward the center of rotation which falls on the center line of the chamber and passed to an outlet opening while de-gassed liquid flows away to the exit pipe at the circumference of the chamber, the improvement comprises a stationary sieve tube arranged coaxially in the chamber wherein the upper opening of the sieve tube is directed towards the outlet opening for the gas and connects the sieve chamber in primary connection with the exit pipe, which has a common center line with the entry pipe. The sieve piercings form a secondary connection to the exit pipe. The sieve tube is preferably installed at an angle of 45.degree. to the field of gravity of the earth.

Abstract: The separator, as independent appliance or as integrated component of inline pumps, has a housing with liquid inlet and outlet connector pipes lying on one common center line and a substantially cylindrical separation chamber arranged therebetween. Into this chamber a liquid-gas mixture is introduced tangentially and set in rotation about the axis (y) of the chamber forming a center of rotation. The gas is forced to the center of rotation and conducted to the exterior while the degassed liquid flows out of the chamber through a separate opening. A plane (A) placed through the common center line (x) of the connector pipes and a plane (B) placed through the chamber axis (y) and standing perpendicularly on the plane (A) produce an intersection line (z) which forms with the center line an angle (a) in the order of magnitude of 0.degree.<.alpha.<90.degree., but preferably .alpha..apprxeq.45.degree..

Abstract: The present invention relates to a control circuit for an A.C. motor with two or several sets of windings. The switch-off phase of the first set of windings is symmetrical with the turn-on phase of the second set of windings, and it is illustrated how to modify the supplied current by simultaneous, symmetrical modification of said phases. As a result a symmetrical field distribution over each pole is obtained even if the turn-on and switch-off phases of the currents supplied to the windings are regulated.

Abstract: A liquid-filled submersible electromotor, especially motor has in one end rotating sealing means for sealingly closing the water-filled space in the motor casing, the sealing means being adapted to automatically release over-pressure in that space and to allow passage of water from the space to the space surrounding the casing, and vice versa. At the other end the motor casing has a bearing for the motor shaft, preferably of the Michell type, wherein one sliding surface is constituted by an annular member of a non-metallic material, preferably ceramics, and the other by movable blocks, also of non-metallic material.