**5.1. Design parameter of the motor**

One of a few design versions of rotary-linear motors is a Twin-Armature Rotary-Linear Induction Motor (TARLIM) shown schematically in Fig. 21. The stator consists of a rotary and linear armature placed aside one another. One generates a rotating magnetic field, another traveling magnetic field. A common rotor for these two armatures is applied. It consists of a solid iron cylinder covered with a thin copper layer. The direction of the rotor motion depends on two forces; linear and rotary, which are the products of two magnetic fields and currents induced in the rotor.

Induction Motors with Rotor Helical Motion 267

**Figure 22.** Dimensions of TARLIM chosen for analyse.

Y = 20.5 <sup>s</sup>

1.1 10.7

D = 150 mm

86

85

**Figure 23.** Rotary armature dimensions.

s

86 mm

**Figure 21.** Schematic 3D-view of twin-armature rotary-linear induction motor.

The TARLIM in its operation can be regarded as a set two independent motors: a conventional rotary and tubular linear motor with the rotors joined stiffly. This approach can be applied only if there is no magnetic link between the two armatures, what practically is fulfilled due to the relatively long distance between the armatures and the low axial speed of the rotors. In case of the motor analysed here both conditions are satisfied and the analysis of each part of the TARLIM can be carried out separately as the analysis of IM 3-phase rotary and linear motors. The only influence of one motor on the other is during the linear motion of the rotor which will be considered at the end of this chapter.

To study the performance of TARLIM the exemplary motor has been chosen with the dimensions shown in Fig. 22. The dimensions of rotary armature are presented in details in Fig. 23.

The core of both armatures is made of laminated steel. The common rotor is made of solid steel cylinder covered by copper layer. Both armatures possess a 3-phase winding. The rotary and linear winding diagrams are shown in Figs. 24.a and 24.b, respectively. The winding parameters and the data of stator and rotor core material are enclosed in Table 1.

**Figure 22.** Dimensions of TARLIM chosen for analyse.

**5.1. Design parameter of the motor** 

fields and currents induced in the rotor.

chapter.

Fig. 23.

Table 1.

**5. Performance of twin-armature rotary-linear induction motor** 

**Figure 21.** Schematic 3D-view of twin-armature rotary-linear induction motor.

The TARLIM in its operation can be regarded as a set two independent motors: a conventional rotary and tubular linear motor with the rotors joined stiffly. This approach can be applied only if there is no magnetic link between the two armatures, what practically is fulfilled due to the relatively long distance between the armatures and the low axial speed of the rotors. In case of the motor analysed here both conditions are satisfied and the analysis of each part of the TARLIM can be carried out separately as the analysis of IM 3-phase rotary and linear motors. The only influence of one motor on the other is during the linear motion of the rotor which will be considered at the end of this

To study the performance of TARLIM the exemplary motor has been chosen with the dimensions shown in Fig. 22. The dimensions of rotary armature are presented in details in

The core of both armatures is made of laminated steel. The common rotor is made of solid steel cylinder covered by copper layer. Both armatures possess a 3-phase winding. The rotary and linear winding diagrams are shown in Figs. 24.a and 24.b, respectively. The winding parameters and the data of stator and rotor core material are enclosed in

One of a few design versions of rotary-linear motors is a Twin-Armature Rotary-Linear Induction Motor (TARLIM) shown schematically in Fig. 21. The stator consists of a rotary and linear armature placed aside one another. One generates a rotating magnetic field, another traveling magnetic field. A common rotor for these two armatures is applied. It consists of a solid iron cylinder covered with a thin copper layer. The direction of the rotor motion depends on two forces; linear and rotary, which are the products of two magnetic

**Figure 23.** Rotary armature dimensions.

Induction Motors with Rotor Helical Motion 269

To verify the modeling results, a real prototype of the motor was built (see Figs. 25 and 26) and tested. The laboratory model of TARLIM has a relatively short secondary length. Therefore, measuring motor performances at linear speed greater than zero was practically difficult so the test was carried out only at zero linear speed. The TARLIM operates practically at low rotary slip and at linear slip close to one. Thus the dynamic end effects does not influence much the motor performance but the static end effect caused by finite

length of each of the armatures has a large impact on the linear motor performance.

armature rotary

armature

The analysis of each part of TARLIM performance is carried out separately as an

linear

**Figure 25.** Laboratory model of twin-armature rotary-linear induction motor.

**Figure 26.** Measurement stand for testing of rotary-linear motors.

independent tubular linear and rotary motor by 3-D FEM modelling.

**5.3. Motor performance** 

**5.2. Experimental model** 

**Figure 24.** Winding diagram of the TARLIM, (a) rotary winding, (b) linear winding.


**Table 1.** Winding and materials data for TARLIM.
