• Standard shaft technology. To avoid the traditional dichotomy between key–smooth shaft applications, Phase Motion Control releases the new standard shaft in which a key seat is filled with an insert (photo below) and the whole set is ground to shaft tolerance. The shaft is therefore round and ready for clamping with conical hubs (recommended). If a key is required (and the corresponding reduced servo performance is accepted) the insert can be removed and a standard key inserted. All shafts are balanced with the insert so that simple rotating parts (e.g. pulleys, gears) need not to be balanced.
• Safety brake: All motors except UL 071040 have an internal cavity where the PM safety brake can be mounted. The brakes are all rare earth permanent magnet type. This new high power density brake operates without brake pads. As a consequence, the problem of pollution of the motor cavity when the brake is operated incorrectly is avoided.
• Additional inertia: an extra flywheel can be introduced in the brake cavity to compensate for poor mechanical linkages between the motor and the load.
• Single piece extruded frame, smooth, with O-rings on all couplings and IP 65 protection to allow flushing and sterilization in food and chemical applications
• Standard circular connectors, turnable 270 degrees, standard high flexibility cables available;
• Oversized front bearings improves bearing life by 70%; 28 mm shaft available on request
• Peak speed 4000 rpm on standard type
• Standard supply: new Heidenhain absolute magnetic encoders, single or multi turn (4096 turns), with electronic nameplate and AUTOSET function (with PMC drives), accuracy 1’, resolution 17 bit/turn, ENDAT full digital serial interface. The motor can also be equipped with sinusoidal optical encoders (Heidenhain ERN 1385, accuracy 20”, interpolated resolution 24 bit/rev, or resolver (accuracy 10’) for low cost, low performance applications.
• KTY 84 linear thermal probe for continuous motor temperature sensing
• Standard lip seal on shaft accessible from outside for maintenance/replacement
• Flange and shaft manufactured to Grade R (reduced tolerance IEC 72)

• Safety brake, permanent magnet, rare earth 24 Vdc, normally locked (Option B)
• Additional rotor inertia (Option J)
• Absolute multiturn encoder Heidenhain EQI 1329, 4096 turns with permanent data retention (mechanical), ENDAT digital serial interface, electronic nameplate, AUTOSET function) (Option N)
• Resolver (Option R)
• Optical sinusoidal encoder Heidenhain ERN 1385, 20” arcsec accuracy (option S)

All specified data are referred to metrological condition; 20 C ambient, sea level air pressure; all data are specified according to the International System (S.I.) and therefore torque is specified in Newton*m, speed in rad/sec, EMF in volt/rad/sec and therefore volt*sec, and so on. Note that due to the homogenous nature of S.I. shaft power is simply speed x torque; while Kt = EMF x sqrt(3).

In general, most specified data are not ambiguous, with the exception of thermal data which are often overlooked or misunderstood. For this reason, a few explanations are supplied in the following.

Loss generation in Brushless servomotors is proportional to the square of the shaft torque and, approximately, to the square of shaft speed. For this reason, when the motion is cyclic, the thermal evaluation can be simply done by performing the root mean square (r.m.s.) calculation of the torque and the speed in the cycle. Such operating point can be utilized in all calculations as if the motor were running at constant speed/torque over such operating point.

Useful hint: in cyclic application (electric cam, flying shears etc., temperature rise is proportional to the square of the cycle frequency.

Once the equivalent operating point of the motor is determined, it must be compared with the motor thermal characteristics to find out whether the resulting motor temperature rise will be acceptable for the application.

In general, all natural convection cooling motors are cooled both by convection in the surrounding ambient, and by conduction, across the front flange, to the body of the actuated machine. Both mechanisms are rather weak, resulting in a thermal impedance much greater that the motor internal thermal impedance. Consequently, and very differently from fan cooled motors, the motor body temperature is very close to the internal hot spot temperature. The motors are all manufactured according to Class H, so a continuous operating temperature of 150 C is acceptable for the motor itself, but may not be for the application, for reasons of operator safety, mechanical stability, lifetime of lubricants etc. The operating temperature target should be chosen when designing the application.

In order to assist in this selections, all motors are characterized on two different operating conditions:

Area 1 represents the most conservative (worst case) condition: conduction through the flange is not considered, and the motor temperature rise is limited to a conservative 65 C; operation inside this area is therefore quite safe without need for further checking;

Area 2 instead defines the maximum performance area, with temperature rise = 100 C, flange monuted on a machine large enough and massive enough that the motor heat adduction would not alter the flange temperature. In general, operation between curves 1 and 2 needs to be evaluated carefully on a case by case basis.