Abstract: A diaphragm pump (1) which has in at least one pump head (2) a working or pump diaphragm (3) which, by means of a clamping zone (4) arranged at its outer circumference, is clamped between two housing parts (5, 6) of a pump housing and which, between itself and a pump head part (6), borders a working or delivery chamber (8) and which, in a central zone (10), surrounds a diaphragm armature (11) which, on a side facing away from the working or delivery chamber (8) of the at least one pump head (2), is connected to a reciprocating drive (12) which is provided for generating an oscillating stroke movement of the working or pump diaphragm (3).

Abstract: A multi-stage diaphragm suction pump, includes at least two pump chambers, each having a inlet having at least one inlet valve, and a outlet having at least one outlet valve, and a suction line, which connects the fluid inlets of the pump chambers. Successive pump chambers are connected to one another by at least one connection line such that, when a differential pressure in the suction line is reached/exceeded, the diaphragm pump changes from parallel to an operating mode that is at least also serial. At least one check valve, which opens to a downstream pump stage, is interposed in each of the inflow and outflow regions of the at least one connection line. A suction-side opening or a pressure-side opening of the connection line is arranged in a region of the pump chamber on which a diaphragm associated with the pump chamber rolls first during a pump cycle.

Abstract: A rotary evaporator (1), to which a clamping insert (59) having a sleeve-like base shape is associated for clamping a vapor feed-through, in the form of a glass hollow shaft (8), in the hub (58) of a rotational drive (57). The clamping insert (2) includes clamping sections (K1, K2) which are spaced apart in the longitudinal direction and carry each at least one clamping slope (63, 64) which is beveled relative to the longitudinal axis of the clamping insert (59). The beveled clamping inclines interact with the associated counter inclines (65, 66) of the rotational drive (57) such that the clamping sections (K1, K2) are pressed against the glass hollow shaft (8) when axial pressure of the clamping insert (59) is applied.

Abstract: A multi-stage membrane suction pump having at least two pump chambers, each having a fluid inlet and a fluid outlet, and having a suction line connecting the fluid inlets. Successive pump chambers are connected via at least one connecting line such that the membrane pump upon reaching/exceeding a differential pressure in the suction line changes from a parallel operation into at least also a serial operation. In the inflow and outflow regions of the at least one connecting line, at least one check valve each is interposed, opening toward the subsequent pump stage. The check valves provided in the connecting line(s) are designed smaller compared to inlet and outlet valves of the pump chambers, and line sections of the connecting lines that open toward the neighboring pump chamber have a smaller clear line cross-section compared to the inlet and outlet valves, and are associated with the check valves.

Abstract: A rotary evaporator (1), having an equipment stand (2) with a protruding guide tower (3), a glass structure (4) which has an evaporation tank (5) and can be displaced on the guide tower (3) for lifting and lowering the evaporation tank (5) thereof, and at least one fluid line that is connected to the glass structure (4). In one embodiment, the guide tower (3) has a channel (17) that is oriented in the longitudinal extension of the tower (3) and in which a line section is provided of at least one fluid line that is connected to the glass structure (4) and opens out into or ends in a flexible tube connection. This flexible tube connection is arranged on a bottom-side region of the rotary evaporator, which faces away from the free end of the guide tower (3), and the glass structure (4) is retained on a carriage (21) that can be displaced laterally on the guide tower (3).

Abstract: A brushless direct current motor including a rotor having permanent magnets, which rotates in a commutation created alternating magnetic field of a stator (1) is provided, which magnetic field is created by a coil system of wire coils (3) applied on an insulating body (4) in the circumferential direction and spaced apart from each other. Control electronics are provided for controlling the electric wire coils, spaced apart from each other, of the control system provided in the stator (1), with non-contact rotary position sensors (5) being allocated to the phases of the coil system (2). In the direct current motor according to the invention the rotary position sensors (5) are arranged on a sensor carrier (13).

Abstract: A vacuum pump stand (1) for generating and regulating the vacuum intended for a rotary vaporizer, including a control device having a control connection to a control unit (4) having at least one control element (3, 6). In the pump stand (1), the control unit (4) is designed as a remote control unit having a wireless control connection to the control device of the pump stand. Laboratory personnel can thus observe the rotary evaporator and the associated pump stand (1) through the divider of a fume cupboard, in order to be able to modify and readjust the process parameters at the remote control panel as needed. Because the remote control unit (4) has a wireless control connection to the control device of the pump stand (1), the fume cupboard no longer needs to be opened, even momentarily. Rather, the pump stand (1) can be operated from a sufficient distance outside the fume cupboard without the laboratory personnel needing to be exposed to special hazards.

Abstract: The invention relates to a diaphragm pump (1) including a working diaphragm (3) that, during pumping movements, oscillates between a bottom dead center and a top dead center. The working diaphragm (3) delimits a pump chamber (7) between itself and a concave pump chamber wall (6) and when located at the top dead center position, the working diaphragm (3) rests against the pump chamber wall (6). The working diaphragm (3) has an inner and an outer annular zone (8, 9), which can be deformed during pumping movements, and a stiffened diaphragm area which, in essence, cannot be deformed during pumping movements is placed between these annular zones (8, 9). This non-deformable diaphragm area can be stiffened, for example, by stiffening ribs (10), which are radially oriented and spaced apart in the circumferential direction.

Abstract: A pump (1) with an oscillating part having a housing (2) with a working chamber (3) and a crankcase (4) defined from the working chamber by the pump part. A pump drive mechanism (6) with a drive shaft (7) is located inside the crankcase (4) and the drive shaft is mounted on bearings (8, 9) that are arranged in the walls of the crankcase. The pump has a suction inlet separate from the crankcase. The pump (1) includes at least one flow channel in the crankcase wall for compensating pressure in the crankcase when the pump part oscillates and a flow damper arranged in the at least one flow channel. In a preferred embodiment, the at least one passage hole having at least one bearing therein is configured as the flow channel.

Abstract: A reciprocating piston machine is provided having at least one membrane (1) produced from an elastomeric material and an oscillating reciprocating drive that acts on a center zone (3) of the membrane (1). Between the center zone (3) of the membrane and its circumferential edge zone (5), a deformable membrane zone (M) is provided that is deformed during the oscillating pumping movements. The reciprocating piston machine according to the invention is characterized in that the work and/or auxiliary membrane (1), in its deformable membrane zone, is provided with at least two cantilever-type annular zones (7, 8) that merge into each other in a reduction of cross-section (9) of the membrane (1) and in that the membrane cross-section, starting from the reduction of cross-section (9), enlarges in the annular zones (7, 8). The membrane of the reciprocating piston engine according to the invention is very durable and functions with little noise.

Abstract: A pump is provided having at least one shield valve controlled by the conveyed medium and having a valve disk (4) of flexible material which is clamped in a central region and is movable between an open and a closed position, in which closed position the valve disk (4) closes at least one valve opening (9). The pump according to the invention includes extensions (11) that project from the valve disk (4) and/or on a valve abutment surface (10) arranged on a side remote from the valve opening (9), for avoiding a sudden flat abutment of the valve disk (4) on the valve abutment surface and/or for limiting the valve opening movement. The pump according to the invention is distinguished by a particularly low noise operation.

Abstract: A pump for gases to be measured having a pump housing in which a pump chamber is located. The pump chamber is sealed off by a working membrane that is connected to a crank drive by a connecting rod or similar lifting mechanism. A heating device is provided in an upper area of the pump housing, particularly in the pump head. Heat insulation covering at least the pump head is provided. The heat insulation is in the form of an insulating housing having an inner wall spaced apart from the pump head in order to form a gas insulation layer.

Abstract: A measuring gas pump (1) including a pump housing (2) with a pump chamber (3) inside which is sealed by a working membrane (5). The membrane (5) is connected: by a connecting rod (8) or a similar type of lifting device to a crank mechanism (9). A heating device is provided in the upper area of the pump housing, specifically in the pump head (10). On one hand, in the drive-transmission area between the head of the connecting rod (6) on the membrane side and the crank mechanism (9), there are holes (11) for the reduction of heat transfer to the crank mechanism which are spaced in a longitudinal direction of the connecting rod and which are also diametrically opposed, in peripheral direction, with a resulting reduction in heat conductivity. On the other hand, there is an enlargement of the surface area, at least in the area adjacent to the crank mechanism, for purposes of heat dissipation, specifically through cooling ribs (12).

Abstract: A rotary piston displacement device having an impeller housng with an approximately cylindrical receiving chamber in which an approximately cylindrical piston, which has a smaller outside diameter than and which is mounted eccentrically relative to, the receiving chamber, is provided mounted on an eccentric drive. The rotary piston forms an approximately sickle-shaped interspace between its outer wall and the inner wall of the receiving chamber. This interspace is divided into a pressure chamber and a suction chamber by a separating crosspiece that is placed between an inlet opening that is located inside the housing and an outlet opening. The outer and inner fixing locations of the separating crosspiece, which is connected to the housing on the one side and the piston on the other side, are offset with respect to one another in the peripheral direction of the rotary piston.

Abstract: A laboratory pump unit (1) for pipetting, filtering, and exhausting a gaseous or liquid fluid is provided. The laboratory pump unit (1) includes a pump (3), which can be connected on the suction side and/or the pressure side to a pipette (4) or other fluid receiver, for suctioning or ejecting the fluid. The laboratory pump unit includes, among other elements, a secondary tube (9, 10) that is connected to the suction tube and/or pressure tube (6, 7) that is connected to the pipette (4) or fluid receiver on the one hand and the pump (3) on the other hand, and is open to the atmosphere, and includes a throttle (11, 12) for limiting the amount of air drawn in or ejected. The laboratory pump unit (1) is operated in “open” pump operation on the suction side and pressure side with a precisely adjusted tube pressure in the suction tube or pressure tube (6, 7), which cannot be exceeded or fallen below by the pump (3).

Abstract: A multistage device (1) for delivering moist gases is provided. Said device comprises several delivery pumps (2, 3) each of which having a displacer that oscillates inside a delivery space, and being connected in series via a connection channel (6). The inventive device also comprises a ventilation device (7) which has at least one ventilation channel (8), whereby the ventilation channel (8) opens into a connection channel (6) that interconnects series-connected delivery pumps (2, 3). The inventive device (1) is characterized in that a ventilation valve (9), which can be motor-actuated by a control device, is interconnected inside the ventilation channel (8), and said ventilation valve (9) can be actuated as required by means of the control device and independent of the lift position of the displacers.

Abstract: A membrane pump (104) with an operating membrane (1) delimiting a conveying space (2), and a supplemental membrane (3) arranged on the side of the operating membrane (1) facing away from the conveying space (2), with a membrane interspace (4) provided between the operating membrane (1) and the supplemental membrane (3) as well as with a pump drive for oscillating movement of the operating and the supplemental membranes (1, 3) in the same direction. The membrane interspace (3) is joined with at least one suction channel (7) for relieving pressure of the membrane interspace (4). The membrane interspace (4) is pneumatically joined through the at least one suction channel (7) with the suction side of this membrane pump (104). The membrane pump of the invention (104) has a high suction capacity without the problem of buckling of the elastic operating membrane (1) in the intake phase.

Abstract: The invention relates to a process for conveying damp gases by means of a conveyor device (1) and also relates to a conveyor device (1) for carrying out the process. The conveyor device (1) has at least one feed pump (2) with an oscillating reciprocating piston (3) in a delivery chamber (7). In order to dry the conveyor device (1) effectively in the region of the delivery chamber (7), the delivery chamber (7) of at least one feed pump (2) is intermittently ventilated at various intervals in time using an ventilation device (15) while the conveyor device (1) is in operation.

Abstract: A reciprocating piston machine (1) with at least one inlet and/or outlet valve that has a strip, tongue or lamella shaped closing member (5). The opening movements (8) of the closing member (5) are limited through a stroke restrictor (6) assigned to each valve. The stroke restrictor (6) has or defines at least one ventilation hole (8) inside the contact area of the closing member (5). This ventilation hole (8) prevents the formation of air cushions (7) between the closing member (5) and the corresponding stroke restrictor (6) effectively. In the absence of the ventilation hole (8), the air cushion (7) can limit the opening movements of the closing member (5) prematurely, which in turn could lead to the generation of additional noise.