Title of Invention

SPINNING FRAME WITH THREAD GUIDING PARTS AND METHOD TO OPERATE SAID SPINNING FRAME

Abstract

In a spinning fame with thread guiding parts, in particular with a ring rail, the thread guiding parts are being connected with a motor (20) through mechanical transmission means. The motor (20) within the stator at the same number of poles is provided with at least two pairs of windings (18a,18b), which are being connectable alternatingly by way of a switch (16) to a power supply (12) of a converter, whereby in a least two operating phases a frequency range are passed through, whose maximum values differ by approximately the factor 3.

Full Text

The present invention relates to a spinning frame with thread guiding parts and a method to operate said spinning frame. In a drive for thread guiding parts of a spinning frame, in particular, a ring rail of a spinning frame, the thread guiding parts are connected with a motor through mechanical transmission means. While in the past mainly mechanical drives have been used for thread guiding parts to be moved backwards and forwards in spinning frames, lately electric drives are being applied increasingly, which make complicated drives redundant. In ring spinning frames of the modem type it is customary to generate alternating movements of a ring rail through mechanical transmission, while extensive stroke movements or stroke shifts in smaller steps are being controlled by an electric motor. It is the object of the present invention to provide a concept where by means of a single drive motor all functions of a thread guiding part can be realised. This object is achieved by an electric motor drive which is being controlled with alternating current of variable frequency, wherein several switchable motor windings with the same number of poles are being provided. Preferably the motor is laid out as synchronous motor for three-phase alternating current, with two windings in the stator for different voltage/frequency conditions, which can altematingly be connected to the three-phase current power supply of a converter. A switch between the different windings of the motor and the connecting lines, which lead to the current supply being provided by the converter, provides for the application of each of the respective windings with alternating current of variable frequency according to the spinning programme, which is stored in a control unit. The solution proposed allows a cost effective and flexible drive of for instance a ring rail of a spinning frame. Accordingly the present invention provides a spinning frame with thread guiding parts, in particular a ring rail of a spinning frame, wherein the thread guiding parts are connected with a motor through mechanical transmission means, characterised in that the motor has a stator with at least two pairs of windings, having the same number of poles which are connectable altematingly by way of a switch to a power supply of a converter which is designed to supply alternating current of variable frequency. Accordingly the present also provides a method to operate a spinning frame with thread guiding parts, in particular with a ring rail, whereat the thread guiding parts are being connected with a motor through mechanical transmission means, characterised in that in a first operating mode at excitation of a first winding with windings the motor is operated by a converter with alternating current in a frequency range between 10 and at least 100 Hz at alternating current voltage up to 400 V, and that in a different phase of operation at excitation of a second winding with windings of the same motor the frequency is increased to above 300 Hz, wherein the variation of the power frequency is actuated through a converter being superset to the control unit of the spinning frame. The boundary conditions for such movements are amongst others as follows: - the stroke speed of the ring rail varies between a few millimetres and over 100 mm/s. - At a selected motor frequency of 360 Hz and a transmission ratio of 1:60 a speed of over 10*000 r.p.m. results for a four-pole synchronous motor. - To achieve the lowest stroke speed of the ring rail the drive on the other hand has to be operated at a speed of less than 200 revolutions. - By controlling the converter with a variable set value voltage of up to 10 V DC a slight change of speed would not be realisable any longer, since the set value input of the analogue voltage would range within the normal interference level. - Furthermore, according to figure 1, the motor has to change is turning direction very quickly within phase C, which requires an extremely low moment of inertia. - During the fast movement of the motor on the other hand a steady load of several kilowatts is necessary. To satisfy all these requirements a synchronous motor, a reluctance motor in particular, is being defined with the following characteristic features during operation of the various stator windings: 1. winding Control frequency of the converter of 5 to 125 Hz, alternating current voltage of 0 to 400 V, set value current of the converter of 0 to 10 V DC or set value current of 0 ... 20 mA. negative motor moment up to a frequency of almost 400 Hz. Said operating phase corresponds with phase E according to figure 1. During standstill - phase A - the motor 20 is being held at rest by way of a direct current excitation of one of the windings 18a or 18b. Additionally, in case of a voltage failures, a mechanical brake is being actuated, which keeps the rotor of the motor 20 at rest, that is in case that one of the electromagnets to disconnect the mechanical brake fails. According to figure 1, switching from the first to the second winding takes place during standstill, during transfer from phase C to phase D or phase D to phase E and phase E to phase A, respectively. The control unit 8 being superset to converter 10 is connected with an input unit 6 as software. The motion programme for the motor 20 is being stored in the control unit in the form of software, this with regard to the speed as well as to the cop formation (form, degree of filling, weight of the cop). The motion programme can be changed by the input of operating parameters, which can be transmitted by the operator through the input unit 6 to the control unit 8. The invention will be described in greater detail hereafter in relation to the drawings wherein show: fig. 1 qualitative a stroke diagram (h) of a ring rail over the time (t) and fig. 2 a wiring diagram of the windings of the motor with the converter. The invention is being explained by way of an example of the ring rail drive of a ring spinning frame. Thereby several contradicting requirements arise, which at first seem to exclude the application of a single motor for the drive. According to figure 1 at the start of the spinning process after a resting phase A, the ring rail has to be moved upward and downward quickly according to phase B. Thereafter follows the actual spinning, that is the winding of tubes with twisted and drawn fibres, according to the pilger step-by-step motion schematic in phase C. The continuous winding of a spinning tube ends with the beginning of phase D, during which in the upper zone of the tube a so called ovenwinding is being applied. After that in phase E the yarn has to be led rather quickly down to the lower part of the tube - phase E -, whereafter the fully wound tubes are being removed from the spinning frame and are being exchanged against empty ones. During all these movements the ring rail is being moved upwards and downwards at strongly varying speeds, whereby the yarn is being led towards the spinning tube at a certain level. Upward and downward motions change quickly, for instance in phase B, furthermore, for a good quality of the spinning cop reversing of the motion in phase C, in particular at the lower reversing point has to take place quickly. During this phase the drive motor operates at a comparably low performance, since the stroke speeds are low. Contrary to this, the power input during phase E is considerably higher, since a fast shift has to take place. 2. winding Frequency of up to 360 Hz, alternating current voltage of 0 V to 400 V and also set value voltage of 0 to 10 V DC or set value current of 0 ... 20 mA. According to figure 2, from a converter 10, which is being controlled by a control unit 8 of the frame with an analogue direct voltage of 0 to 10 V (0 ... 20 mA), power supply lines 12 run to a least one consumer, which is being indicated as motor 20. Between the power supply lines 12 and a switch 16 run three lines 14 for the three phases of the alternating current of variable frequency, whereat the switch 16 allows the application of alternating current on the first winding (windings 18a) or on the second winding (windings 18b). The operating mode is as follows: During operation of the first winding during phase C (windings 18a) the motor 20 lifts and lowers the ring rail in a continues reversing motion. A stroke timing is between 10 and 60 s. The downward speed is preferably twice as high as the upward speed. At permanent operation within a frequency range of the alternating current of between 3 and approximately 50 Hz a power input of approximately 300 W is being achieved. The reversing acceleration, that is the frequency change during transfer from the upward to the downward movement within the spinning phase C, has to amount to at least I"OOO Hz/s. This can only be achieved with a highly dynamic motor, with a dynamic moment in relation to the mass inertia moment of the motor with a value of over 4"000 Nm/kgm^. During the excitation of the second winding (windings 18b) during short period operation, which only lasts a few seconds, the motor 20, during (power) application of the windings 18b after the position change of the switch 16 has to be operated with a frequency of between 125 and approximately 300 Hz during the lowering movement, beyond that the same applies also during a field weakening with a We Claim: 1. Spinning frame with thread guiding parts, in particular a ring rail of a spinning frame, wherein the thread guiding parts are connected with a motor (20) through mechanical transmission means, characterised in that the motor (20) has a stator with at least two pairs of windings (18a, 18b), having the same number of poles which are connectable altematingly by way of a switch (16) to a power supply (12) of a converter (10) which is designed to supply alternating current of variable frequency. 2. Spinning frame as claimed in claim 1, wherein the motor (20) is laid out as a synchronous motor. 3. Spinning frame as claimed in any one of the claims 1 or 2, wherein the motor (20) is laid out in such a way that its dynamic moment in relation to its acting mass moment of inertia amounts to at least 4 "000 Nm/kg2. 4. Spinning frame as claimed in any one of the claims 1 to 3, wherein between the motor (20) and the converter (10) no means are provided for the feedback of the speed or position of the motor. 5. Spinning frame as claimed in any one of the claims 1 to 3, wherein a control unit (8) is being superset to the converter (10), said control unit being connected with an input unit (6). 6. Method to operate a spinning frame with thread guiding parts, in particular with a ring rail, whereat the thread guiding parts are being connected with a motor (20) through mechanical transmission means, characterised in that in a first operating mode at excitation of a first winding with windings (18a) the motor (20) is operated by a converter (10) with alternating current in a frequency range between 10 and at least 100 Hz at alternating current voltage up to 400 V, and that in a different phase of operation at excitation of a second winding with windings (18b) of the same motor (20) the frequency is increased to above 300 Hz, wherein the variation of the power fi-equency is actuated through a converter (10) being superset to the control unit of the spinning frame. 7. Spinning frame with thread guiding parts, substantially as hereinabove described and illustrated with reference to the accompanying drawings. 8. Method to operate a spinning frame with thread guiding parts, substantially as hereinabove described and illustrated with reference to the accompanying drawings.

Documents:

0912-mas-1999 abstract.jpg

0912-mas-1999 abstract.pdf

0912-mas-1999 claims-duplicate.pdf

0912-mas-1999 claims.pdf

0912-mas-1999 correspondence-others.pdf

0912-mas-1999 correspondence-po.pdf

0912-mas-1999 description (complete)-duplicate.pdf

0912-mas-1999 description (complete).pdf

0912-mas-1999 drawings-duplicate.pdf

0912-mas-1999 drawings.pdf

0912-mas-1999 form-1.pdf

0912-mas-1999 form-19.pdf

0912-mas-1999 form-26.pdf

0912-mas-1999 form-3.pdf

0912-mas-1999 form-4.pdf

0912-mas-1999 form-5.pdf

0912-mas-1999 others.pdf

0912-mas-1999 petition.pdf