Abstract: A coolant nozzle carrier for use with a grinding machine that has a grinding spindle for supporting and driving a grinding disc with a rotational axis. The coolant nozzle carrier comprises at least two coolant nozzles and at least a center leg and two side legs that are attached to the center leg. Each of the side legs supports at least one nozzle and extends in a plane that is perpendicular to the rotational axis. The side legs are configured to accommodate the grinding disc in between the side legs with a moving gap defined between the grinding disc and the side legs.

Abstract: A coolant nozzle carrier for use with a grinding machine that has a grinding spindle for supporting and driving a grinding disc with a rotational axis. The coolant nozzle carrier comprises at least two coolant nozzles and at least a center leg and two side legs that are attached to the center leg. Each of the side legs supports at least one nozzle and extends in a plane that is perpendicular to the rotational axis. The side legs are configured to accommodate the grinding disc in between the side legs with a moving gap defined between the grinding disc and the side legs.

Abstract: The positioning of a cylindrical workpiece (that has to be machined by grinding) can be performed particularly precisely if the workpiece abuts to at least one, preferably two, static supporting elements and is fixed in a collet of a spindle, which allows a wobble compensation as well as a radial displacement of the spindle axis relative to the longitudinal axis of the workpiece.

Abstract: The positioning of a cylindrical workpiece (that has to be machined by grinding) can be performed particularly precisely if the workpiece abuts to at least one, preferably two, static supporting elements and is fixed in a collet of a spindle, which allows a wobble compensation as well as a radial displacement of the spindle axis relative to the longitudinal axis of the workpiece.

Abstract: The invention relates to a sensorless electric motor and a method of controlling such an electric motor, which motor comprises a permanently magnetic rotor, a stator having at least one winding, and a power stage for influencing the current flowing through the winding. As a function of a predetermined commutation duration (T_K), a commutation period is defined, during which period the direction of the magnetic field generated by current flow through the winding is not modified, during which period a commutation completion operation (107) and a commutation initiation operation (109) take place, and which period starts at a first commutation instant (t_KN) and ends at a second commutation instant (t_KN+1); preferably, commutation timing is adjusted, based upon a value of induced voltage picked up at a currently non-energized one of the winding strands, during a plateau portion (108) of a winding voltage trace, located temporally between commutation instants.

Abstract: A method is disclosed for controlling the commutation in an electronically commutated motor (20) which comprises a stator having at least one phase (24, 26), and a permanent-magnet rotor (22), and with which a current limiter (36, 58) and a controller (18) for regulating a motor variable are associated. The current limiter (36, 58) serves to limit the current (I) in the at least one phase (24, 26) to a setpoint value. The regulation by means of the controller (18) is accomplished by modifying the distance in time (W) between switching on (t1) and switching off (t2) of the current (i1, i2) in the at least one phase. In this method, the setpoint value to which the current limiter limits the current (i1, i2) in the relevant phase is modifiable.

Abstract: A valve features a deflectable actuating element (1) that controls the movements of at least one actual sealing element (3) for opening and/or closing at least one sealing contour (6), and the actuating element is loaded via an elastic element (5) essentially perpendicularly relative to the direction of the deflection; and the longitudinal axis of the actuating element and the force applied by the elastic element are aligned in a position of the actuating element that is between its two extreme positions. The actuating element (1) is preferably an unilaterally loaded piezoelectric bending transducer, and the sealing element (3) is preferably a toggle that has the ability to swing around an axis arranged perpendicularly relative to the direction of the deflection of the actuating element (1).

Abstract: Valve with a displaceable actuating device that controls the movements of at least one actual sealing element for opening and closing, and the actuating device is loaded with an elastic element essentially in a perpendicular direction relative to the direction of displacement, and the longitudinal axis of the actuating device and the force exercised by the elastic element are aligned in one position of the actuating device between its two extreme positions. In order to realize a valve that can be electrically switched using minimal currents and that is characterized, in particular, by its small construction size but that is still able to achieve large regulating distances, the actuating device is a unilaterally constrained piezoelectric bending element.

Abstract: An improved method of commutating an electronically commutated DC motor shuts off application of power between the end of one current pulse and the beginning of the subsequent current pulse. Based upon the instantaneous rotation speed, one calculates at what instant to shut off the power. During the power interruption, the disconnected winding is operated in short-circuit mode using two MOSFET transistors, and the decay of the current is monitored. When the current reaches a predetermined reduced value, the terminals of the winding are switched to a high-resistance state, until the subsequent current pulse is started. This has the advantage that less reactive power occurs during operation, and one need not install as bulky a storage capacitor as the capacitors used heretofore.

Abstract: A method of limiting current in a DC motor acts on a full bridge circuit (137) through which the stator winding arrangement (102) of that motor is supplied with current. Upon response of the current limiter, energy supply to the stator winding arrangement (102) from the DC power network is interrupted. The stator winding arrangement is then operated substantially in short circuit via semiconductor switches of the full bridge circuit, and the decaying current flowing in that context serves substantially to continue driving the motor. When that current has reached a lower value, energy supply from the DC power network to the motor is once again activated. The effective value of the current flowing to the motor is preferably reduced when the current limiter responds. The time period during which that current flows, in the form of current blocks, is then increased in compensatory fashion.

Abstract: An electronically commutated motor has a rotor (108), a stator having a stator winding arrangement (102), and a full bridge circuit (137) for controlling the current (i1, i2) in the stator winding arrangement (102); in the full bridge circuit (137), first semiconductor switches (114, 130) are connected to a first DC supply lead (116) and second semiconductor switches (132, 136) to the other DC supply lead (122), said second switches being bidirectionally conductive of current in the switched-on state. The motor has an arrangement (172, 198, 188) for opening the first semiconductor switches (114, 130) and for closing the second semiconductor switches (132, 136) during a predetermined operating state. An arrangement (202) is provided for monitoring the direction of the current (i1, i2) which flows in the second semiconductor switches (132, 136) when the latter are conductive during the predetermined operating state.