RasuunDrive^®

Ratio

The reduction ratio describes the relationship between the input movement and the output movement. With a reduction ratio, the output movement is smaller than the input movement.

Self-locking

With self-locking, the forces caused by friction are always greater than the applied adjustment forces due to the geometric relationships of the sliding partners. Due to the geometric conditions, the sliding partner in which the force is initiated cannot be moved relative to the sliding parter on which the adjustment force is applied.

Travel range

The travel range describes the travel range available for the application. The travel range characteristic describes the characteristic of the travel range as a function of the angular position of the eccentric. It is defined such that at an angular position of 0 degrees, the eccentric is perpendicular to the resulting movement direction and has no deflection in the adjustment direction. The max. travel range specifies the maximum available travel range of an eccentric kinematics.

Repeatability unidirectional

The unidirectional repeatability describes the positional uncertainty that arises when repeatedly approaching a setpoint from the same direction with no load. The repeatability is defined as half of the maximum difference together with a +/- sign.

Repeatability bidirectional

The bidirectional repeatability describes the positional uncertainty that arises when repeatedly approaching a setpoint from the opposite direction with no load. The repeatability is defined as half of the maximum difference together with a +/- sign.

Accuracy

The positioning accuracy of a gear describes the maximum deviation of the output angle relative to the setpoint or, with a linear actuator, the maximum deviation of the output position relative to the setpoint. The measurement is performed during a complete rotation of the output element or a complete traverse of the travel range path with the aid of a high-resolution measurement system. There is no change in the direction of rotation or direction reversal. The positioning accuracy is defined as the absolute value of the maximum difference between the theoretical setpoint position and the measured actual position of the output element.

Resolution

The positioning resolution refers to the smallest angular change or positional change that can be distinguished by the positioning system. With eccentric systems, the characteristic of the linearly resulting positioning resolution is described as a function of the angular position and thereby indicates the smallest positional change as a function of the angular position that can be distinguished by the positioning system. With eccentric systems, it is defined such that at an angular position of 0 degrees, the eccentric is perpendicular to the resulting movement direction.

Lost motion

The value for the lost motion can be ascertained from the characteristic of the hysteresis curve of a gear or linear actuator. Lost motion is defined as the angular difference or position difference at which the two branches of the hysteresis curve cross the torque or force zero point, i.e., no load is applied. The hysteresis curve is determined by subjecting the output to load while the input is blocked with a clockwise and an anticlockwise torque or a forward-acting and a backward-acting force and the corresponding angular displacement or positional change measured.

Backlash

The backlash can be ascertained from the characteristic of the hysteresis curve of a gear or linear actuator. Backlash is defined as the range in which the characteristic of the hysteresis curve is vertical, i.e., an angular change or a positional change occurs without changing the torque or the force. The hysteresis curve is determined by subjecting the output to load while the input is blocked with a clockwise and an anticlockwise torque or a forward-acting and a backward-acting force and the corresponding angular displacement or positional change measured.

Rated force

Rated torque or rated force is defined as the torque or force at which the service life is achieved under rated conditions, i.e., rated speed. With drive systems, the motor torque may, in some cases, not be adequate for overcoming the running torque of the complete system under rated conditions.

Peak force

The peak torque or peak force is the loading of the components in the drive train, e.g., the teeth of the gears, still below the fatigue strength. This does, however, result in increased tooth wear, which leads to a reduction in the service life. With drive systems, the motor torque may, in some cases, not be adequate for overcoming the running torque of the complete system at peak torque or peak force.

Momentary peak force

With momentary peak torque or momentary peak force, the elastic deformations of the teeth are still small enough that no tooth meshing problems occur and proper function is ensured. The loads do, however, exceed the limit of the fatigue strength. Thus, the number of loads should be minimised. Should it occur once, breakage or failure will not result. With drive systems, the motor torque may, in some cases, not be adequate for overcoming the running torque of the complete system at momentary peak torque or momentary peak force.

Rated speed

Rated output speed or rated speed is defined as the speed at which the service life is achieved under rated conditions, i.e., rated torque or rated force. With drive systems, the motor torque may, in some cases, not be adequate for overcoming the running torque of the complete system at rated speed.

Maximum speed

The maximum output speed or maximum speed refers to the speed before which mechanical damages occur to components in the drive train, e.g., scoring of the teeth. With drive systems, the motor torque may, in some cases, not be adequate for overcoming the running torque of the complete system at maximum speed.

Lifetime for rated operation

The service life is defined by means of the rated operating point, i.e., rated speed and rated torque, as well as a change of the accuracy characteristics, i.e., unidirectional repeatability, transmission accuracy, lost motion, of less than 10% of the respective catalogue value.

Radial backlash output shaft

Possible deflection of the mounted shaft in the radial direction without applied force.

Axial backlash output shaft

Possible deflection of the mounted shaft in the axial direction without applied force.

Max. axial load on output shaft (non-operating, impulsive load)

Max. permissible axial load on the output shaft (not in operation, force applied impulsively) Describes the maximum permissible axial load on the output shaft, whereby the drive is not in operation, i.e., is at a standstill and the force is applied impulsively. Decisive for the determination is the static load bearing capacity of the ball bearings, which, in the impulsive case, corresponds to just one third of Co, as well as the elastic deformation of the output shaft due to the stiffness of the output bearing and the associated position of the dynamic spline.

Moment of inertia

The moment of inertia specifies a body’s resistance to change its rotational movement.

Weight

The weight of the drive without cables and plugs.

Min. permissible ambient temperature (non-operating)

Minimum permissible temperature at which the drive may be stored or decommissioned without being impaired or destroyed as a result.

Min. permissible ambient temperature (operating)

Minimum permissible temperature at which the drive can be operated.

Max. permissible ambient temperature (non-operating)

Maximum permissible temperature at which the drive may be stored or decommissioned without being impaired or destroyed as a result.

Max. permissible ambient temperature (operating)

Maximum permissible temperature at which the drive can still be operated.

Maximum speed of motor

The maximum speed of the motor describes the speed before mechanical damages occur to the commutator, the rotor or the bearing.

Resonance frequency of motor

Describes the step frequency at which the rotor can experience resonance vibrations while the motor is operated under no load. It is recommended that this frequency be avoided in normal operation and that the motor be started at a higher frequency or that half- or micro-steps be used. Additional inertial masses, e.g., through a gear, reduce the resonance frequency.

Holding torque of motor (unpowered)

Describes the torque developed by the motor while at a standstill.

Rated current of motor

The phase current that may flow through both phase coils without the motor overheating while at an ambient temperature of 20°C and constant operation.

Rated voltage of motor

The rated voltage corresponds to the voltage at which all other rated characteristic values of the motor, particularly the rated current at 20°C, are set, measured and classified.

Phase resistance of motor

The phase resistance describes the ohmic resistance of the coil of a phase at an ambient temperature of 20°C in the steady state.

Inductance of motor

Describes the inductance of the coil of a phase at an ambient temperature measured at 1 kHz.

Amplitude BEMF of motor

Describes the amplitude of the bemf.

Full step angle of motor

The full step angle of the motor describes the angle at which the rotor turns if a phase is advanced.

Angular accuracy of step of motor

The angular accuracy of step describes the deviation of the current rotor position from the ideal target rotor position, whereby no external load is applied.

Electrical time constant of motor

The electrical time constant describes the time required to achieve 67% of the possible phase current of a specified operating point.

Max. coil temperature of motor

The maximum temperature that may occur in the coil without destroying the magnets or the coil. The coil temperature can be calculated by measuring the change in resistance and the temperature coefficient alpha, which is dependent on the coil wire material. T1 = 1/alpha * (R1/R0 + alpha*T0 – 1)

Thermal resistance of motor between coil and housing

Describes the thermal resistance of the motor between coil and housing.

Thermal resistance of motor between housing and air

Describes the thermal resistance of the motor between housing and ambient air.

Thermal time constant of the coil of the motor

Describes the thermal time constant of the motor coil.

Thermal time constant of the housing of the motor

Describes the thermal time constant of the motor housing.

Insulation voltage of motor

Describes the insulation voltage of the motor.

Pitch

RoHS compliant

At Micromotion GmbH, hazardous materials, which are referred to in EU directive 2011/65/EU, are purchased/used only in compliance with this directive.