Title of Invention

GODET UNIT FOR GUIDING AND ADVANCING A YARN

Abstract

Godet unit for guiding and advancing a yam The invention relates to a godet unit for guiding and advancing a yam with a rotating godet jacket. The godet jacket is mounted to a rotor shaft, which is driven by means of a three-phase motor. The three-phase motor is activatable via a frequency inverter, the frequency inverter being provided with a housing, whose interior accommodates the electronic subassemblies of the frequency inverter in stationary and heat transferring manner. In accordance with the invention, the housing of the frequency inverter is firmly connected to the housing of the three-phase motor.

Full Text

GODET TWIT FOR GUIDING AND ADVANCING A YARN The invention relates to a godet unit for guiding and advancing a yarn as defined in the preamble of claim 1. Such godet units are known and commonly used in particular for guiding and advancing synthetic filament yarns. DB 37 01 077 Al discloses such a godet unit, wherein the godet jacket is connected to a rotor of an electric motor and driven by same. For regulating the rotational speed of the known godet unit, it is necessary that the electric motor be activated by a frequency inverter. In this connection, it must be ensured that the preselected operating speeds remain constant on the godet unit and that they are reproducible. As can be noted from "Textilpraxis International", 1992, pages 3 7-3 8, the frequency inverter is accommodated in a control cabinet separated from the godet unit and connected via cables to the electric motor > of the godet unit. The consequence thereof are long, inverter-fed motor lines, which require increased protection. Furthermore, it is necessary to guide the rotational speed signals of the godet unit over long distances through the machine, which brings along an increased susceptibility to breakdown. It is therefore the object of the invention to further develop the known godet unit such as to minimise cabling requirements and susceptibility to breakdown. A further object of the invention is to realize a frequency inverter that is adapted to the surroundings of the godet unit. In accordance with the invention this object is achieved by the elements of claim 1. Accordingly, the frequency inverter with its electronic subassemblies is encased in stationary and heat transferring manner in a housing, whose surface is constructed for dissipating heat. The housing is firmly connected with a housing accommodating a three-phase motor. This construction allows to realize a very compact godet unit, which hae the special advantage that the supply of alternating current to the motor occurs directly in the godet unit. Consequently! long supply lines of ac voltage are no longer"needed, thus eliminating the susceptibility to breakdown of the supply. The direct addition o£ the frequency inverter to the three-phase motor has also the advantage that the rotational speed signals from the drive to the frequency inverter are transmitted directly in the godet unit over a very short distance. This makes it possible to maintain the operating speeds of the godet very accurately, which is o£ advantage in particular in the case of draw zones comprising a plurality of godets, Advantageously, the encasement of the frequency inverter is designed and constructed such that vibrations as occur in a godet do not lead to breakdowns ia the electronic layout. Furthermore, internal losses within the frequency inverter that are converted to heat, are advantageously dissipated via the housing. In a higher driving power range from about 500 W to 12 kw, losses from 20 w to 500 W are already incurred, which would lead without heat dissipation very rapidly to a high temperature for the electronic components. The present godet unit has furthermore the advantage that the electronic devices are engineered more purposefully and thus coat-favorably with respect to the kind of drive, and that they can be manufactured at little cost* An advantageous further development of the invention provides that the three-phase motor and the housing of the frequency inverter are arranged in axial relationship to one another/ which is more favorable, in particular with respect to compactness and heat transfer. A further advantageous embodiment of the godet unit provides that the housing of the frequency inverter is furnished with cooling ribs- This is advantageous, in particular in a godet unit operating in a higher power range. A specially advantageous further development of the invention provides that the housing of the frequency inverter consists of a bottom part and a top part which are furnished with different cooling ribs, and which ate insulated from one another against heat. This permits corresponding outward dissipation of losses that variously arise in the subassemblies of the frequency inverter, without heating additionally electronic components sensitive to leaser losses- Thus, in a frequency inverter substantial losses of power occur in the power component, which are by a factor of 50 higher than the loss of power incurred in the control electronic devices contained in the frequency inverter. As a result of the heat insulation between the bottom and the top part, the operating temperature in the interior of the housing is maintained advantageously at an acceptable level. The coupling of the power semiconductors with the top part having a large cooling surface and the coupling of the control electroaic devices with the bottom part having a small cooling surface is especially advantageous for a controlled heat transfer and heat dissipation. In a preferred variant of the godet unit in accordance with the invention, a fan ie arranged in the housing of the. frequency inverter. This allows to accomplish that the heat transfer of the loss energy of the power component and the loss energy of the control electronic devices to the housing walls are improved. Furthermore, this allows to keep the operating temperature at a level that is acceptable for the control electronic devices, even in a higher power range of as much as 12 kW. To extract the dissipation heat from within the housing of the frequency inverter, it will be also advantageous, when the installation space of the housing occupies, compared to the cross section of the housing, a relative proportion which amounts preferably to about one third of the cross sectional area. This allows to attain an optimum of heat dissipating surface of the housing. Another advantageous further development of the godet unit includes a godet housing which ie slipped in cup-shape over the frequency inverter and the three-phase motor, and which is mounted with its open end to the godet flange or the three-phase motor. This arrangement allows to realize a very compact structural unit, which provides the three-phase motor and the frequency inverter with an additional protective casing to keep away vapors and lint. In particular, it is accomplished that the housing surface of the frequency inverter with its cooling ribs is not subjected to any contaminations and that, thus, a heat exchange with ambient air can occur freely. Another advantageous further development of the godet unit accommodates a fan wheel with a drive unit in the godet housing, which is slipped in cup-shape over the frequency inverter and the three-phase motor. This fan wheel permits generation of a cooling air current;, which flows along the cooling ribs of the frequency inverter housing and amplifies the dissipation of heat. To this end, the closed end of the godet housing is provided with openings ao as to facilitate an exchange of air. This ie advantageous in particular in the case of godet unite being operated in a higher power range, or in the case of godet unite having a heated jacket. To generate a circulating cooling current, the mount of the godet housing to the godet flange or the housing 'of the three-phase motor is made air permeable. This permits in addition an improved cooling of the three-phase motor. To generate a purposeful cooling current along the cooling ribs of the inverter housing, it will be especially advantageous, when the fan is supported on a cover, which is arranged in axial direction directly on the inverter housing. However, it is also possible to support the fan on the godet housing. This version has the advantage that vibrations generated by the fan are unable to propagate directly to the housing of the frequency inverter* In godet units, which are operated at very high speeds, it is necessary that the bearings of the rotor shaft are provided with lubricating oil. To this end, an oil pump is used, which is arranged likewise in the godet housing, preferably in axial direction behind the fan. This arrangement permits to realize very short supply paths that are to be covered between the oil pump and the godet bearing. As a result of the invention, a godet unit is created, which can be used universally at any desired location in a spinning line or a textile machine. The operation of the godet unit requires only a supply of ac voltage as well as a data transmission to a central machine control unit. The regulation of the rotational speed occurs automatically in the godet unit. Additional, advantageous further developments of the godet unit in accordance with the invention are defined in the dependent claims. In the following, embodiments are described in more detail with reference to the attached drawings, in which: Figure 1 shows a godet unit of the present invention with an integrated drive and a frequency inverter; Figure 2 is a cross sectional view of a frequency inverter with housing/ Figures 3 and 4 show further embodiments of a godet unit with integrated drive and frequency inverter; and Figure S is a schematic, cross sectional view of a frequency inverter with a housing and a fan. Figure l shows a godet unit with an integrated drive and frequency inverter. The godet unit comprises a godet flange 1 which has a bore 32 for receiving bearings 5 that support a rotor shaft 4. Mounted to godet flange 1 is a projecting, tubular shaft 2 coaxial with bore 32, the rotor shaft 4 extending concentrically with an air gap through the projecting, tubular shaft 2. The rotor shaft 4 projects with its free end beyond the free end of tubular shaft 2. This end of rotor shaft 4 mounts a godet jacket 3, The godet jacket 3 is cup-shaped with a front wall 9 thereof having a bore 10 and an extension 9.1. The free end of rotor shaft 4 is provided with a taper 7. Over this taper, extension 9.1 of godet jacket 3 is slipped and firmly connected to the rotor shaft by means of a clamping element 8. The godet jacket 3 is slipped over projecting, tubular shaft 2, so that an installation space 6 ia formed between godet jacket 3 and shaft 2. Depending on the application of the godet, the installation space 6 may accommodate a heating element for heating the godet jacket. Depending on the heating element, the godet jacket could be heated by radiation, convection, or induction* On the side opposite to the godet jacket, a three-phase motor 30 is mounted to godet flange 1. The three-phase motor 30 has a housing 12 which accommodates a stator with a winding 15. In concentric relationship with stator 15, a rotor winding 1* is mounted on a recessed rotor section 13 at the other end of rotor shaft 4, Energy is supplied to the three-phase motor 30 via a plug connection 19 which connects a frequency inverter 31 to the three-phase motor 30. The frequency inverter 31 with its housing 17 is coupled directly in axial direction to the housing 12 of the three-phase motor, Between housing 12 and housing 17 of frequency inverter 31 an insulating plate 33 may be arranged for damping vibrations. Accommodated in housing 17 of the frequency inverter are electronic subassemblies, such as a power component and control electronic devices. The frequency inverter 31 is connected by means of plug connections 20.1 and 2Q,2 to a supply line 27 and a control line 28 of a central unit of a machine control or a control cabinet. The housings 12 and 17 are accommodated in a godet housing 11, the latter being slipped thereover in cup-shape and mounted to godet flange 1. This embodiment of the godet unit (not shown) is suitable to operate godet* at a low wattage. The stationary heat exchange between the housing surface of frequency inverter 31 and the ambient air suffices to maintain an acceptable temperature level. In godet unit* operating in a higher power range --as shown in Figure l -- a fan wheel 21 is arranged in the axial extension to the three-phase motor and frequency inverter on a front wall 34 of godet housing 11. The fan wheel 21 is mounted on a fan shaft 22 supported in front wall 34 of the godet housing, and it is driven by means of a fan motor 33.. The fan motor 23 is connected via plug connections 24 and 2S to a supply line 26. Thus, the cooling of the drive of the godet unit is separate from the supply of the drive. In operation, the frequency inverter 31 is supplied with direct current. The three-phase current changed by frequency inverter 31 activates three-phase motor 30, so that the rotor shaft 4 is driven at a predetermined speed. The rotational speed of rotor shaft 4 is detected by means of a speed sensor 29 and supplied, via a signalling line 35 to the control electronic devices o£ the frequency inverter. In this compact arrangement, the interface between the three-phase motor and the frequency inverter is inaccessible. Consequently, for purposes of monitoring, the control electronic devices of the frequency inverter have been programmed in advantageous manner, ao that process-relevant parameters/ such as rotational speed and current, can be inquired via a serial port and be supplied to a central unit. Figure 2 is a cross sectional view of the frequency inverter of Figure 1. In thiB Figure, the godet housing XI is omitted. The housing 17 consists o£ a top part 36 and a bottom part 37. The top part 36 and the bottom part 37 are interconnected via a heat insulation 44 and form in the interior an installation chamber 41. Formed on the outer surface of top part 36 are cooling ribs 38. Formed on the outer surface o£ the bottom part are cooling ribs 39. Arranged in installation chamber 41 are the electronic subassemblies. In this arrangement, a printed circuit card 55 of the power component with a transistor 40 is secured in vibrationproof manner by means of mounting elements 56 directly to the top part 36, whereas a printed circuit card 43 of the control electronic devices is connected to bottom part 37 by means of mounting elements 57. The printed circuit card 55 and fehe printed circuit card 43 are interconnected via a plug connection 58, To improve the heat transfer between printed circuit card 43 and bottom part 37, the space therebetween may advantageously be filled at least in places with a highly heat conductive materialr which acts as an electrical insulator. Since the power semiconductors release a significant portion of the dissipation power of the frequency inverter, a temperature gradient develops in the installation chamber 41. Thus, a temperature of about 130°C adjusts itself on the inner side of top part 36 and a temperature of about 70° on the inner side of bottom part 37. To avoid that the temperature on the bottom part is increased in addition by power semiconductors 40, a heat insulation 44 is arranged between top part 36 and bottom part 37« Furthermore, the cooling surface formed by cooling ribs 38 is substantially larger than the cooling surface formed by cooling ribs 3d. This arrangement has the advantage that the dissipation heat can be extracted directly at its place of origination. Furthermore, it is avoided that the acceptable temperature of electronic components having a limited temperature stability is not exceeded, which applies in particular to the control electronic devices Figures 3 and 4 illustrate further embodiment* of a godet unit. The mechanical layout of the godet unit is identical with the godet unit of Figure 1, so that the description of Figure 1 is herewith incorporated by reference. Therefore, like parts are provided with like numerals. In the embodiment of Figure 3, the housing 12 of three-phase motor 30 and an adapter plate 4S are mounted to godet flange 1 by means of anchor bolts 46, Furthermore, the' frequency inverter housing 17 and a cover 47 which is mounted to the side of the inverter facing away from the three-phase motor, are connected to adapter plate 45 by means of an anchor bolt 53. The cover 47 mounts the fan motor 33 with fan shaft 22 and fan wheel 21. Provided on front wall 34 of godet housing 11 is a clamp terminal 48. The supply of power to the godet unit is ensured via plug connection 49 and plug 50 with a line 51. The supply of power and activation of the inverter proceed from terminal box 48 via line 52 to plug connection 58. The fan motor 23 is energized from terminal box 48 via line 54. This arrangement has the advantage that the adapter plate 45 permits suppression of vibrations between the godet flange and the frequency inverter. In the arrangement shown in Figure 3, the adapter plate 45 can also be used with advantage as a cover for the inverter housing. In this connection, it is to be noted that the interelement protection IP 54 or IP 64 be maintained, which is realized by inserting seals between the adapter plate and the inverter housing. In addition, the godet unit brings about the advantage that it can be installed from the operating side of the machine through a round opening in the machine frame. Likewise, as has been described with reference to Figure 3, in the embodiment of Figure 4 the housing 17 of the frequency inverter is mounted to adapter plate 45 by means of anchor bolt 53. Simultaneously, anchor bolts 53 secure cover 47 which is arranged in axial direction on the opposite front side of housing 17 accommodating frequency inverter 31. The cover 47 is provided with a frame 52. The cover 47 and frame 62 Berve to accommodate fan 21 as well as an oil pump 61 and terminal box 48 with plug 49. via an oil line 63, the oil pump 61 connects to bearings 5 of rotar shaft 4. In this arrangement, the godet housing 11 is mounted with its free end to housing 12 of the three-phase motor, and it encloses all units. At its closed and, the godet housing 11 has an opening fo* plug connection 49 and plug 50. In the wall of godet housing 11, at,the closed end thereof, openings 60 are arranged. These openings facilitate a cooling air current, which is generated by means of fan 21 in the interior of the godet housing. In this instance, the godet housing 11 can be mounted to the three-phase motor housing 12 such as to permit an exchange of air. Thus, a permanent cooling air current 64 flows through the axially aligned cooling ribs of housing 17 accommodating the frequency inverter. Likewise, an air current is directed to the three-phase motor 30, thereby cooling same. This configuration of a cooling system permits the godet unit of the present invention to be realised for a maximum power range of as much as 12 kw. In this case, it may be advantageous to effect within the housing 17 of frequency inverter 31 a forced air cooling of the electronic components. To this end/ an embodiment is shown in Figure 5. The housing as well as the components are identical with those in the embodiment of Figure 2, so that the description thereof is herewith incorporated by reference. Unlike the version shown in Figure 2, the printed circuit card 43 is secured by means of mounting elements 57 to the power component. In the space between the printed circuit card 43 and the bottom part 37, a fan 59 is supported in the wall of bottom part 37. The fan 59 generates an air current inside installation chamber 41, and it is operated by means of a fan drive 65. This measure of a forced air cooling in installation chamber 41 allows to accomplish that the dissipation of heat to the wall of housing 17 is improved. The forced air cooling of the electronic components within housing 17 can advantageously be assisted by a special configuration of the bottom part and top part. The godet unit of the present invention can be used in the spinning process or in a textile machine at any location provided for this purpose. The special configuration of the frequency inverter facilitates controlling environmental conditions with respect to temperature, contamination, and vibration. Likewise, the encasement permits compliance with the types of protection against moisture, lint and dust. As a drive, it is preferred to vae synchronous, or even asynchronous motors. Godet flange Tubular shaft Godet jacket Rotor shaft Bearing Installation space Taper Clamping element Front wall Extension Bore Godet housing Housing Recessed rotor section Rotor winding Stator winding Control electronics Housing Power semiconductor Plug connection Plug connection Pan wheel Fan shaft Pan motor Plug connection Plug Power cable Supply line Signalling line Rotational speed sensor Three-phase motor Frequency,inverter Bore Insulating plate Front wall Signalling line Top part Bottom part Cooling ribs Cooling ribs TraneiBtor Installation chamber Control electronic devices/printed circuit card Heat insulation Adapter plate Anchor bolt Cover Clamp terminal, terminal box Plug connection Plug Line Line Anchor bolt Line Printed circuit card Mounting element. Mounting elament Plug connection Ventilation, fan Openings oil pump Frame Oil line Air current Pan drive WE CLAIM 1. Godet unit for guiding and advancing a yarn with a rotating godet jacket (3) which is connected with a rotor shaft (4) of a three-phase motor (30), the three phase motor (30) being activatable via a frequency inverter (31) with electronic subassemblies* (18, 43), characterized in that the electronic subassemblies (18, 43) of the frequency inverter (31) are encased in stationary and heat transferring manner in a housing (17), whose surface is designed and constructed for dissipating heat, and that the housing (17) is firmly connected with a housing (12) of the three-phase motor (30) . 2. Godet unit as defined in claim 1, characterised in that the housing (17) of frequency inverter (31) is arranged axially relative to housing (12) of three-phase motor (30). 3. Godet unit as defined in claim 2, characterized in that the housing (17) of frequency inverter (31) is mounted to an adapter plate (45). 4. Godet unit as defined in claim 3, characterized in that the adapter plate (45) and the housing (12) of three-phase motor (30) are mounted to a godet flange (1) . 5. Godet unit as defined in one of claims 1-4, characterized in that the housing (17) is provided on is surface with coaling ribs (38, 39), which extend externally in axial direction, and that the electronic subassemblies (18, 43) are arranged on the inner side of the housing (17) facing the cooling ribs (38# 39) . 6. Godet unit as defined in claim bf characterized in that the housing (17) consists of a bottom part ■ (37) and a top part (36), that the bottom part (37) and the top part (36) are provided on their surface with cooling rib3 (38, 39), which are formed on the bottom part (37) and on the top part (36) differently in shape and/or number, and that the bottom part (37) is heat insulated against the top part (36). 7. Godet unit as defined in claim 6, characterised in that a power component (18) of the frequency inverter (31) is mounted in heat transferring manner to the top part (36) . 8. Godet unit as defined in one of claims 6 or 7, characterized in that a control electronic device (43) of the frequency inverter (31) is arranged in heat traneferring manner on the bottom part (37). 9. Godet unit as defined in one of claims 6 or 7, characterized in that the control electronic device (43) of the frequency inverter (31) is mounted stationarily to the power component (16) • 10. Godet unit as defined in one of claims 1-9, characterized in that s the housing (12) of frequency inverter (31) accommodates a fan (59). 11. Godet unit as defined in one ot claims 1- 10, characterized in that the housing (17) of frequency inverter (31)' consists of aluminum, 12. Godet unit as defined in one of claims 1- 11, characterized in that the housing (17) of frequency inverter (31) has a cross aection forming a circular enclosure. 13. Godet unit as defined in claim 12, characterized in that in the housing (17) an installation chamber (41) is formed, which occupies a proportionate area smaller than 40%, preferably about 30%, of the surrounding housing cross section* 14. Godet unit as defined in one of claims 1- 13, characterized in that a godet housing (11) is slipped in cup-shape over the frequency inverter (31) and the three-phase motor (30), and that the open end of godet housing (11) is mounted to the godet flange (1) or to the housing (12) of three-phase motor (30). 15. Godet unit as defined in claim 14, characterized in that the godet housing (11) is provided at its closed end with openings (60), and that the godet housing (ll) accommodates a fan wheal (21) with a drive unit (22, 23) > 16. Godet unit as defined in claim 15/ characterized in that the fan wheel is supported on a cover (4?),' and that the cover (47) itself is mounted axially with the housing (17) to the adapter plate (45) . 17. Godet unit as defined in one of claim© 14- 16. characterized in that the godet housing (11) accommodates an oil pump (€1) for supplying the godet bearing (5) with lubricating oil. 18. Godet unit ae defined in one of claims 14- 17, characterized in that: a plug connection (24, 25) is arranged in godet housing (11), so as to facilitate a power transmission and a signal transmission to a central unit. 19. Godet unit for guiding and advancing a yarn, substantially as herein described, with reference to the accompanying drawings.

Documents:

1432-mas-1997- abstract.pdf

1432-mas-1997- claims duplicate.pdf

1432-mas-1997- claims original.pdf

1432-mas-1997- correspondence others.pdf

1432-mas-1997- correspondence po.pdf

1432-mas-1997- description complete duplicate.pdf

1432-mas-1997- description complete original.pdf

1432-mas-1997- drawings.pdf

1432-mas-1997- form 1.pdf

1432-mas-1997- form 26.pdf

1432-mas-1997- form 3.pdf

1432-mas-1997- form 4.pdf