AC motor

An AC motor is an electric motor that is operated on alternating current. Our eccentric diaphragm pumps can be equipped with shaded-pole motors for operation on alternating current. Our electromagnetically driven pumps (linear pumps, vibrating armature pumps, pivot pumps) are usually operated on alternating current.


BL motor

Brushless motor, see → Brushless pump

Brushless motor

see → Brushless pump

Brushless pump

Pumps with a brushless drive ("brushless motor, BL motor, BLDC motor") offer a particularly long life expectancy. A brushless motor is an electric motor without carbon brushes (sliding contacts). In conventional brushed motors, the carbon brushes are used for the electrical connection between rotor and stator via slip rings or commutators. These brushes are subject to wear due to mechanical abrasion and brush fire. With the brushless electric motor, there are no commutators or brushes. A BL motor has a higher efficiency due to its low friction and a longer service life due to the lower wear.

We offer you our brushless pumps for gases and liquids with a variety of different BL motors: different voltages, analogue or PWM control, with or without integrated electronics and with or without control input or frequency output. We would be happy to advise you on choosing the right BL motor for your brushless pump!


Cable assembly

Our pumps can be equipped with cables, plugs (or sockets) and mounting options according to customer requirements in order to integrate them quickly and easily into the respective peripherals. In addition, numerous customizing options are available to our customers in order to precisely adapt the performance data of the pump and the chemical properties of the materials used to the specific application.


In order to be able to transport aggressive gases, acids and alkalis reliably, all wetted parts of the pump must be chemical-resistant. Our modular system offers you a variety of different plastics and elastomers to adapt your pump to the desired chemical requirements.


Electrical and pneumatic (or hydraulic) connections are required to operate the pump. On request, we can supply your pump with ready-made connection cables and plugs or with unassembled solder lugs. In addition, we can provide the pumps with various tubing connections (e.g. barbed fittings, internal threads for screwed hoses, manifold connections with O-ring seals).


All parameters of our pumps can be precisely adapted to specific customer requirements. This concerns both the desired pneumatic or hydraulic performance of the pump (flow rate, pressure, vacuum, suction height) and the choice of suitable materials (chemical and physical properties of plastics and elastomers). In addition, we provide you with a variety of different motors, tubing connections, cable assemblies and accessories. Thanks to our modular system, we can implement customer requests within a few days - without additional development-related costs!


DC motor

A DC motor is an electric motor that is operated with direct current. Iron-core motors, high-quality coreless motors and particularly durable brushless motors are available for Schwarzer Precision pumps. Our vane pumps and rotary diaphragm pumps as well as most of our eccentric diaphragm pumps are driven by DC motors. Alternatively, our eccentric diaphragm pumps can also be equipped with AC shaded-pole motors and thus operated on AC voltage.


The specified dimensions of our pumps (length, width, height) refer to the maximum housing dimensions including motor and connectors. Any tubes, connection cables and pump accessories (suction filters, non-return valves, pressure switches, etc.) that may be present are not included in the specified dimensions.


The drive converts the electrical control of the pump into a mechanical movement to convey the medium. We supply our eccentric diaphragm pumps with iron core motors, coreless motors, brushless (BLDC) motors or AC shaded pole motors. Our vane pumps are equipped with coreless motors, the rotary diaphragm pumps are driven by iron core motors. In addition, we manufacture various types of pumps with non-rotating electromagnetic drives (linear pumps, vibrating armature pumps, pivot pumps).

Dual Head

Pump with two pump heads that are driven together by one end of the motor shaft (type designation "-DU"). The two pump heads are at a 180° angle to each other so that the pumped medium (gas or liquid) is sucked in or expelled alternately. Dual-headed pumps can be configured → in series or → in parallel.

Dual Head parallel

Two-headed pump with parallel configured tubing (type designation "-DUp"). The parallel tubing adds the flow ("volume flow") of both pump heads, resulting in a particularly high delivery volume.

Dual Head serial

Two-headed pump with serial configured tubing (type designation "-DUs"). The serial tubing combines the pressures (or vacuum) generated by both pump heads, resulting in a particularly high total pressure (or vacuum).


Abbreviation of pump types (e.g. "SP 620 EC-DUp-DV"), see → Dual Head parallel


Abbreviation of pump types (e.g. "SP 620 EC-DUs-DV"), see → Dual Head serial



Abbreviation of pump types (e.g. "SP 270 EC-THp"), see → Eccentric diaphragm pump


The eccentric mounted on the motor shaft is used to convert the rotary motion of the electric motor into an oscillating up and down motion of the connecting rod. The desired stroke of the diaphragm movement is realized by the size of the eccentric.

Eccentric diaphragm pump

Motor-driven pump that cyclically moves a diaphragm up and down using an eccentric and connecting rod. The diaphragm moving downwards creates a negative pressure, which sucks the pumped medium into the pump chamber via an inlet valve. As soon as the diaphragm moves upwards again, the pumped medium is pressurized. The inlet valve is closed by the resulting overpressure, at the same time the outlet valve is opened and the pumped medium flows out. Eccentric diaphragm pumps from Schwarzer Precision are particularly robust and reliable, gas-tight, maintenance-free and outstandingly controllable.

Electrolyte circulation

The charging time of a lead-acid battery can be significantly reduced by circulating the electrolyte. For this purpose, air is blown into the electrolyte liquid of the battery with a pump. This circulation prevents crystal formation during the charging process, which means that higher charging currents and shorter charging times can be achieved. Our vibrating armature diaphragm pumps ("SA-EUW") are specially optimized for electrolyte circulation in battery chargers.

Elektromagnetic drive

Pumps with an electromagnetic drive are usually operated on AC voltage. The drive consists of an iron core coil and a magnetic armature. The current-carrying coil generates an alternating magnetic field that causes the armature to oscillate. The armature drives a pump head that pumps the medium by a membrane and two valves (inlet / outlet). Pumps with an electromagnetic drive are particularly wear-resistant because they have no mechanical bearings. With upstream electronics ("inverter"), these pumps can also be operated with DC voltage.


EPDM (ethylene propylene diene monomer) is an elastomeric material that is typically used in our pumps as the standard material for valves, seals and diaphragms. EPDM is excellent for use with non-aggressive gases and liquids.


Abbreviation of pump types (e.g. "SP 203 SA-EUW"), see → Electrolyte circulation



see → Fast closing valves


The flow ("delivery rate, pumping rate, volume displacement, volume flow") of a pump describes the delivered volume per unit of time (e.g. 100 ml/min or 1 l/h).


Abbreviation of pump types (e.g. "SP 125 FZ"), see → Vane pump



The pump housing serves as a casing for mechanical protection against accidental contact and for electrical insulation. Our housings are made of durable, high-quality plastic (e.g. PPS). Individually selectable options are available for fastening the pump in the customer device (e.g. screw fastening, clamp fastening, manifold connection, etc.).



see → Customising


Operating voltage

Depending on the desired application, our pumps can be connected to a wide variety of operating voltages. We can supply you with motors in all common DC and AC voltages.


Plain bearings

Plain bearings (also called "friction bearings, sleeve bearings, slide bearings, bush bearings") are made of particularly low-friction plastics or sintered bronze. They are compact and inexpensive. Plain bearings are primarily used for short running times. For use with long running times and/or high loads, we equip our pumps with ball bearings.


On customer request our pumps can be assembled with different plugs. The plugs are primarily used to supply power the pump. Pumps with brushless motors may also have connections for data lines on the plugs (e.g. sensor output, control input, etc.).


The pressure generated on the outlet side of our pumps is specified relative to the ambient pressure (pump at rest = 0 mbar pressure).

Pressure delivery

Depending on the intended use, our pumps can be optimized for pressure or vacuum applications. Pumps for pressure delivery are mainly designed to achieve a certain positive pressure or a certain working point with positive pressure ("pressure-optimized pump").

Pressure switch

A pressure switch ("pressurized switch, threshold switch") combines the functions of a sensor and a switch. The electrical switching process is triggered as soon as the pressure level measured by the sensor at the pump outlet exceeds or falls below a certain limit value ("threshold value"). The switch can be designed as an opener, closer or switch ("changeover").

pumping rate

see → Flow


Rotary vane pump

see → Vane pump



A self-priming pump can draw in liquids even when dry without having to completely fill the delivery system beforehand. This is particularly important for open conveying systems where the pump can suck in air during operation ("dry run").

serial tubing

When configuring the tubing ofa two-headed pump in series, the outlet of the first pump head is connected to the inlet of the second pump head. This combines the pressures (or vacuums) generated in both stages. In this way, a particularly high pressure or a particularly high vacuum can be generated.


The stroke of a pump describes the length of the distance that is necessary for the complete deflection of the diaphragm (top dead center to bottom dead center). With our eccentric diaphragm pumps, the stroke is defined by the size of the rotating eccentric. In the case of electromagnetically driven pumps (vibrating armature diaphragm pumps, linear pumps, pivot pumps), the stroke is caused by the deflection of the armature vibrating in the magnetic field.


Twin Head

Two-headed pump with a centrally mounted motor and two parallel pump heads (type designation "-TH"). The motor shaft extends out of both sides of the motor housing and drives one pump head each. Tubing of twin-head pumps can be configured in series or in parallel.

Twin Head parallel

Two-headed pump with parallel configured tubing (type designation "-THp"). The parallel configured tubing combines the flow ("volume flow") of both pump heads, resulting in a particularly high delivery volume.

Twin Head serial

Two-headed pump with serial configured tubing (type designation "-THs"). The outlet of the first pump head is connected to the inlet of the second pump head. The serial configured tubing combines the pressures (or vacuum) generated by both pump heads, resulting in a particularly high total pressure (or vacuum).



The vanes ("rotary vanes, vane cell plates") are part of the pump head of a rotary vane pump. The vanes move in the guide slots of the revolving rotor and are responsible for transporting the medium.

Vane pump

Our miniature vane pumps ("rotary vane pumps") are displacement pumps for suction or pressure delivery of air and other gases. They consist of a rotor that revolves eccentrically inside a cylindrical stator (pump housing). The rotor is pressed onto the motor shaft and has four radially arranged slots. The vane cell plates ("rotary vanes") sit in these guides. The centrifugal forces generated during rotation move the rotary vanes outwards in their guide slots and press them against the inner surface of the stator, dividing the space between rotor and stator into four pumping chambers. These rotating chambers transport the medium from the inlet to the outlet of the pump. Vane pumps are characterized by particularly low pulsation and linear adjustability. In addition, our vane pumps work completely oil-free and maintenance-free.

Volume displacement

see → Flow

Volume flow

see → Flow


Working Point

The working point of a pump defines the flow (volume flow) at a specific back pressure or vacuum (e.g. 1.0 l/min flow at 100 mbar back pressure).