Abstract:
A stator for a linear motor is described. The stator has a stator member with a coil arrangement, a connecting member with external terminals, a sensor arrangement having at least one Hall sensor, and terminals for the sensor arrangement, as well as a holding member. The holding member is subdivided into a connecting member insertion portion and a stator member insertion portion and has holding devices for disposing the stator member and the connecting member stationarily, releasably and in an accurate position with regard to each other.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This is a U.S. national stage of application No. PCT/EP2008/006240, filed on Jul. 29, 2008. Priority is claimed on German Application No.: 10 2007 038 847.2, filed Aug. 16, 2007 the content of which is incorporated here by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a stator of a linear motor, in particular for driving sliding doors. 
         [0004]    2. Description of the Related Art 
         [0005]    Linear drives for sliding door systems are well known. To determine a position of a sliding door leaf driven by a linear drive, Hall sensors, disposed within the stator, are used. Usually, they are incorporated into a coil arrangement of the stator of the respective linear motor. 
         [0006]    It is disadvantageous that, at the time of manufacturing the stator, the Hall sensors need to be incorporated into the coil arrangement. This circumstance leads to fact that the Hall sensors can not be tested separately from the coil arrangement. If the coil arrangement is configured as a module and, is molded by a casting compound, a future exchange of defective Hall sensors is not possible. Furthermore, dimensioning the sensitivity of the Hall sensor system needs to be known at the time of manufacturing the coil arrangement. A future adaptation is either not possible or only possible by recalibrating the evaluation circuit, which is expensive. 
       SUMMARY OF THE INVENTION 
       [0007]    An object of the invention is to reduce the shortfalls of the state-of-the-art. 
         [0008]    According to one embodiment of the invention, a stator for a linear motor comprises a stator member, which has a coil arrangement, a connecting member which has external terminals, a sensor arrangement with at least one Hall sensor and external terminals for this sensor arrangement, and a holding member for receiving the stator member and the connecting member. The holding member is subdivided into a connecting member insertion portion and a stator member insertion portion. The holding member has holding devices, which allow for a stationary, accurately positioned, and releasable disposition of the stator member and of the connecting member with regard to each other. 
         [0009]    The separation into a stator member and a connecting member has the advantage of the stator member being solely responsible for generating the alternating magnetic field. The sensor system is accommodated in the connecting member. The sensor system does not have to be present at the time of manufacturing the stator member. Both members, the stator member and the connecting member, respectively the sensor system can be tested in parallel and separately from each other, i.e. individually, which is in particular advantageous if there are different manufacturers for the stator member and the sensor system. 
         [0010]    In addition, it is possible to exchange the sensor system in the event of failure, without having to exchange the entire stator member, representing additional cost advantages. 
         [0011]    Furthermore, the inventive stator preferably has at least two attachment portions. The attachment portions are configured such that the stator can be mounted by these portions to a carrying profile, which in turn is or will be attached at a wall or at a ceiling. 
         [0012]    Mounting the holding member is realized by fixing means. According to the invention, these fixing means may be formed by clamping screws, which, during screwing, are propped up against an inside wall of a carrying profile, the holding member being propped up against an opposite side at the carrying profile. This provides the possibility to change the position of the stator, even after the stator is installed. 
         [0013]    As an alternative, the fixing means may comprise screws, which, during installation, are screwed into a housing of the carrying profile. This provides the possibility to omit the described support for the stator at the carrying profile, and to be able to utilize a holding member, which, at least in the sidewall areas, is less stable, resulting in cost advantages. 
         [0014]    According to one embodiment of the invention, the holding member preferably has a separation wall, which effects a subdivision of the holding member into the connecting member insertion portion and the stator member insertion portion and is disposed between the connecting member and the stator member. As an alternative, this separation may be achieved by one of the at least two attachment portions. This separation into two independent portions allows for separately optimizing the holding member with regard to the installation of the connecting member and the stator member. 
         [0015]    Preferably, the separation wall comprises lead-throughs for lines, which serve to fix connecting lines which are to be coupled between the connecting member and the stator member. Thereby, the lines are reliably held and a risk of damaging one of the connecting lines is considerably reduced, if not eliminated at all. In addition, this simplifies mounting the inventive stator at the carrying profile because it can be mounted to the carrying profile as a whole. 
         [0016]    The holding devices may comprise spring elements by which the stator member is resiliently pressed against a side of the separation wall, respectively of the attachment portion, facing the stator member. This leads to an accurately positioned disposition of the stator member. 
         [0017]    As an alternative or in addition, the holding devices may have at least one holding projection, configured in the stator module insertion portion and in a sidewall of the holding member, which projection is disposed to extend from the sidewall in the direction of another opposite sidewall of the holding member. A coil former of the coil arrangement of the stator member has at least one holding recess such that, when inserting the stator member into the stator module insertion portion of the holding member, the at least one holding recess reaches engagement with the at least one holding projection. Thereby, a particular simple installation and an accurately positioned disposition of the stator member are possible. 
         [0018]    As an alternative, at least two adjacent coils of the coil arrangement, at least at opposite corners facing each other, may have respectively one sparing. The sparings are configured such that, with the stator member being assembled, they result in the shape of the above described holding recess, and, during insertion into the holding member, reach engagement with a respective holding projection. 
         [0019]    This has the advantage that, instead of a recess, a sparing may be provided in the respective corner, for example by a chamfering. 
         [0020]    Preferably each coil has one of the described recesses or sparings at the respective same location. This allows for having to produce only one type of coil former, which considerably reduces the cost with regard to the number of required manufacturing tools and thus makes possibly additional production machines redundant. 
         [0021]    According to one embodiment of the invention, the separation wall preferably ends below an upper termination of one of the attachment portions. A space is thereby created above the separation wall between sidewall sections of the holding member, respectively between a respective sidewall section and the at least one attachment portion located in the vicinity of the separation wall or integrally configured with it. The space can be used for running cables and/or individual lines across the coil arrangement, for example to a second stator. The space thus forms a cable duct. 
         [0022]    According to one embodiment of the invention, the holding devices may comprise holding noses or projections, which are disposed in the connecting member insertion portion of the holding member. The connecting member is clipped between the holding noses, allowing for a very simple installation of the connecting member. 
         [0023]    Furthermore, the holding devices may comprise a spring element by which the connecting member is resiliently pressed against a side of the separation wall, respectively of the one attachment portion, facing away from the stator member, which circumstance serves to accurately position the connecting member with regard to the separation wall, respectively the attachment portion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    Further features and advantages of the invention will result from the following description of preferred embodiments, in which: 
           [0025]      FIG. 1  is a perspective view of a stator according to an embodiment of the invention; 
           [0026]      FIG. 2  is a plan view of the stator of  FIG. 1  from above; 
           [0027]      FIGS. 3A-3C  are the stator of  FIG. 2  in an enlarged section with locking elements according to different embodiments of the invention; 
           [0028]      FIG. 4  is a sectional view of a connecting member insertion portion along a line  4 - 4  of the stator illustrated in  FIG. 2 ; 
           [0029]      FIGS. 5A-5D  are pre-tensioning devices in different embodiments; 
           [0030]      FIG. 6  is a sectional view along a line  6 - 6  of the stator illustrated in  FIG. 2 , inserted in a carrying profile; 
           [0031]      FIGS. 7A and 7B  are a sectional views along a line  7 - 7  of the stator illustrated in  FIG. 2  in different embodiments, respectively in two mounting conditions and inserted in a carrying profile; 
           [0032]      FIG. 8  is a sectional view along a line  8 - 8  of the stator illustrated in  FIG. 2 , and 
           [0033]      FIG. 9  is a stator with a holding member according to a second embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]      FIG. 1  is a stator  1  according to a first embodiment of the invention together with a rotor  2 . The rotor  2  comprises of a row of magnets or is made from magnetizable material. Usually, the rotor  2  is attached at a non-illustrated sliding door leaf. 
         [0035]    The stator  1  comprises three parts: a stator member  10 , a connecting member  20 , and a holding member  100 . 
         [0036]    The stator member  10  has a coil arrangement  11 , which is provided with a magnetic keeper  15  in a known manner. The stator member  10  generates an alternating magnetic field for moving the rotor  2  along a longitudinal extension of the stator member  10 . In addition, if desired, it may assume a carrying function, for example with regard to a sliding door leaf to be moved. 
         [0037]    The stator member  10  is received in the holding member  100 . The holding member  100 , seen in a longitudinal direction, i.e. in ±x-direction in  FIG. 1 , has two portions located one behind the other, a connecting member insertion portion  108  and a stator member insertion portion  109 . 
         [0038]    As can be seen in  FIG. 1 , the stator member  10 , seen in y-direction, has a magnetic keeper  15  on its rear side, which is preferably composed of laminated core members. 
         [0039]    Furthermore, the stator member  10  has a coil former  12 , about which non-illustrated windings are wound. Preferably, the coil formers  12  are fitted onto the keeper  15  and more preferably they are molded with it to form a module. 
         [0040]    At an end of the holding member  100 , remote from the connecting member insertion portion  108 , preferably one terminal wall section  114  is disposed, respectively configured. 
         [0041]    Furthermore, preferably at least two attachment portions  106  are provided, for mounting the stator  1  at a non-illustrated carrying profile. One of the at least two attachment portions  106  is preferably disposed between the connecting member insertion portion  108  and the stator member insertion portion  109 , whereas the second attachment portion is preferably disposed in the vicinity of the terminal wall section  114  and is preferably integrally configured with it. 
         [0042]    For the purpose of separating the connecting member insertion portion  108  from the stator member insertion portion  109 , preferably a separation wall  101  is provided which extends from a lower portion of the holding member  100  in y-direction and in ±z-direction. The other one of the at least two attachment portions  106  is preferably disposed in the vicinity of the separation wall  101  and is preferably integrally configured with it. 
         [0043]    The stator member  10  is inserted into the insertion portion  109  and is supported, preferably resiliently pre-tensioned against a side of the separation wall  101 , with respect to the other attachment portion  106 , facing the stator member  10 . A constant distance to the separation wall  101 , with respect to the other attachment portion  106 , is achieved. In this case, the separation wall  101  or the other attachment portion  106  preferably serves as a prop-up surface for the stator member  10  and/or for the connecting member  20 . 
         [0044]    As shown in  FIGS. 3   a  to  3   c , positioning the stator member  10  may be achieved by an engagement of at least one coil former  12  of the coil arrangement  11  with at least one sidewall  103  of the holding member  100 . For this purpose, at least the one sidewall  103  has a projection  105 , for example in the shape of an engagement nose or projection, in an area in which it is disposed adjoining a coil former  12 . The adjoining disposed coil former  12  has a preferably complementarily configured recess  13  at a corresponding location. Upon inserting the coil former  12 , the at least one projection  105  reaches engagement with the corresponding recess  13 . 
         [0045]    To improve the stability of the positioning, a similar projection  105  may be configured at the opposite sidewall  103  and a second recess  13  at the corresponding side of the respective coil former  12 . 
         [0046]    The recesses  13  may likewise be provided at different coil formers  12 , as shown on the right side in  FIG. 3   a . This is advantageous in that respectively only one side of at least two coil formers  12  needs to be provided with a recess  13 . 
         [0047]    If each coil former  12  is respectively provided with two recesses  13 , cost advantages are achieved in that only one type of coil former  12  needs to be manufactured; consequently only one manufacturing tool is required. 
         [0048]    According to another alternative shown in  FIG. 3   b , at a respective corner of a coil former  12 , sparing  14  is provided instead of recesses  13 . The associated projection  105  is disposed or configured correspondingly offset in the sidewall  103 . 
         [0049]    According to an alternative shown in  FIG. 3   c , the respective projection  105  is disposed such that, seen in the z-direction in  FIG. 3   c , a central line of a respective projection  105  is disposed between edges of two directly adjacent coil formers  12 , which edges face each other. The two directly adjacent coil formers  12  have respectively one sparing  14 , for example in the shape of a triangle, disposed at the corners, which face each other and are directly adjacent to the projection  105 . The sparings  14  form respectively one half of a recess  13 . By two directly adjacent coil formers  12 , one recess  13  is formed analogously to the one shown in  FIG. 3   a.    
         [0050]    The described projections  105  may be configured to be continuous, when seen in y-direction in  FIGS. 3   a  to  3   c , whereby the respective recesses  13 , or sparings  14  need to be configured such that, seen in y-direction in  FIGS. 3   a  to  3   c , a continuous hollow space exists between coil former  12  and a respective sidewall  103 . 
         [0051]    The projections  105  are preferably arranged in a lower area of the holding member  100  such that such a continuous hollow space is not required. 
         [0052]    In the event the coil former  12  should have some play after being inserted into the holding member  100 , there is a risk of the coil former  12  changing its position. An additional non-illustrated pre-tensioning device may be provided such that the stator member  10  is supported resiliently pre-tensioned. 
         [0053]    To position the connecting member  20  with regard to the stator member  10  as precisely as possible, as shown in  FIG. 4 , an attachment device in the shape of holding noses  112  is provided. The holding projections  112  are disposed in a lower portion of the holding member  100  and are disposed or configured to face each other. The connecting member  20  is clipped into the holding projections or noses  112 , which represents a very simple mounting. 
         [0054]    In the event there is play between the connecting member  20  and one of the holding noses  112  in the installed condition, analogously to the stator member  10 , the connecting member  20  may be likewise supported resiliently pre-tensioned. 
         [0055]    The described solution with the projection  105  for the stator member  10  is applicable to the connecting member  20  as well. Usually the connecting member  20  has a circuit board. Accordingly, the circuit board or a respective bottom part of the connecting member  20  has the respective recess(es)  13  or sparing(s)  14 . 
         [0056]    The described solution with the holding projections  112  for the connecting member  20  is applicable to the stator member  10  as well. In this case, the stator member  10  does not require any recesses  13  or sparings  14 . In this case, the sidewalls  103  preferably have holding projections  112 , respectively at least two holding projections  112  being disposed or configured preferably at each sidewall  103  and point into the direction of the respective other sidewall  103 . 
         [0057]    With regard to the spring pre-tensioning, different solutions are indicated by way of example for the stator member  10  in  FIG. 5 . Analogously they are applicable to the connecting member  20 . 
         [0058]    As illustrated in  FIG. 5A  a pre-tensioning device according to a first embodiment of the invention, is formed by a spring projection  113 , which is preferably cut out of the wall section  114  or formed therein. It extends in in the −z-direction in  FIG. 5A , and its free end protrudes in the −x-direction, i.e. in the direction of the stator member  10 , respectively of the connecting member  20 . 
         [0059]    According to a second embodiment shown in  FIG. 5B , the pre-tensioning device is likewise formed by means of a spring projection  113 ′ cut out of the wall section  114  of the holding member  100 . The spring projection  113 ′ is configured to protrude in a central area into the direction of the stator member  10  or of the connecting member  20 . The difference to the embodiment shown in  FIG. 5A  is that the spring projection  113 ′ has no free end. 
         [0060]    As an alternative, the pre-tensioning device  30  may be formed by a separately configured spring. According to a variant shown in  FIG. 5C , it is preferably a spring element  113  configured as a hinge spring. However, it may as well be formed by means of a helical spring, as shown in  FIG. 5D , which is propped up at the wall section  114 . 
         [0061]    Obviously, other spring arrangements are possible as long as they urge the stator member  10 , respectively the connecting member  20  into the direction of the respective other member  20 , or  10 . 
         [0062]      FIG. 6  shows a sectional view of the stator  1  along the sectional line  6 - 6  in  FIG. 2 . As can be seen, the stator  1  is inserted into a carrying profile  40 . Only the portion of the carrying profile  40 , intended to receive the stator  1  is illustrated. Even if the carrying profile  40  is illustrated as being closed at the top, above the stator  1 , it may be configured in any optional way. 
         [0063]    As shown in  FIG. 6 , the stator  1  is simply inserted or introduced into the carrying profile  40  and rests on projections  41 , respectively configured on the sides in  FIG. 6 . 
         [0064]    As shown in  FIG. 6 , the attachment portions  106 , and possibly the separation wall  101 , respectively the non-illustrated wall section  114 , terminate in a central section, preferably above the connecting member  20  and the stator member  10 , in this view located behind the separation wall and therefore not visible. If one separation wall  101  and/or one wall section  114  are present, those terminate in areas laterally of the respective attachment portion  106 , in  FIG. 6  respectively below the attachment portions  106 . This means that respectively one hollow space is created in the areas lateral to the attachment portions  106  and lateral to the walls of the carrying profile  40 . These areas are preferably provided for allowing to run or install cables  3  or individual lines  4  there through. 
         [0065]    This is particularly favourable, if, for example, two stators  1  are to be controlled by the same control circuit. A second application case could be, if power lines and/or data lines are to be run to sensors, such as smoke detectors, hall sensors  200 , or the like. 
         [0066]    For connecting the stator member  10  to the connecting member  20 , in the case of a separation wall  101 , lead-throughs  102  for lines are provided in the wall at least in an area lateral to the respective attachment portion. In the simplest configuration, they consist of wedge-shaped slots, into which the respective connecting line  110  is pressed and thus fixed. According to a further embodiment of the invention, the insulation of the respective connecting line  110  is cut in. 
         [0067]    As shown in  FIG. 6 , the sidewalls  103  of the holding member  100  preferably end at a height corresponding to the attachment portions  106 , at least in areas corresponding to the respective attachment portion  106 . Thus, in conjunction with the keeper of the non-illustrated coil arrangement  11 , a reception space in the shape of a cable duct is created for the cables  3  or lines  4 . Thereby the cables  3 , respectively the lines  4  may be incorporated into the stator  1 , i.e. run inside the latter, before the stator is mounted to the carrying profile  40 . 
         [0068]    To stationarily mount the stator  1 , according to a first embodiment of the invention shown in  FIG. 7A , the preferably two attachment portions  106  have a through-opening  42 , which, in  FIG. 7A , extends vertically and has a female thread. An attachment screw  107 , in this case in the shape of a threaded pin with a hexagon socket, is screwed into the through-opening  42  from the bottom in  FIG. 7A . When installing the stator  1 , the attachment screw  107  is thus accessible from the bottom. 
         [0069]    During installation, a hole  115  is pre-drilled into the carrying profile  40  at a desired location with an interior diameter, which is smaller than or equal to an exterior diameter of a thread of the attachment screw  107 . 
         [0070]    When mounting the stator  1 , upon screwing, the attachment screw  107  cuts into the carrying profile  40 , leading to the condition shown on the right hand side in  FIG. 7A . 
         [0071]    As an alternative, the through-opening  42  in the attachment portion  106  is configured without a thread and has a diameter, which is equal to or slightly larger than an exterior diameter of the thread of the threaded pin  107 . At a lower end, i.e. at its head end, the attachment screw  107  preferably has a larger exterior diameter than at its threaded portion, and the through-opening  42  has a larger interior diameter in an area for the head of the attachment screw  107 . The attachment screw  107  is thus simply screwed tight in the carrying profile  40 , however not in the attachment portion  106 . 
         [0072]    Any kind of attachment screw, for example a counter-sunk bolt, is useable instead of the threaded pin  107 . Furthermore, a clamping can be provided, as long as it offers sufficient reliability for mounting and fixing the stator  1  in the carrying profile  40 , in particular during operation with interaction with a rotor  2 . 
         [0073]    In comparison with the solution illustrated in  FIG. 7A , instead of screwing into the carrying profile  40 , according to the solution shown in  FIG. 7B , it can be intended for the attachment screw  107  to be propped up against an upper interior side of the carrying profile  40 . A screwing of the attachment screw  107  results in a clamping of the stator  1  between said upper interior side and holding projections  41  of the carrying profile  40 , on which the holding member  100  comes to rest at lower edge areas. This solution is advantageous in that the stator  1  can be mounted and fixed non-destructively (with regard to the carrying profile  40 ), a circumstance that further simplifies and improves a subsequent displacement of the stator  1 . No possible holes, already existing in the carrying profile  40 , need to be respected. 
         [0074]      FIG. 8  shows a sectional view along a line  8 - 8  of the stator illustrated in  FIG. 2 . The coil former  12  comprises a diagrammatically illustrated winding  16 , the keeper  15  being essentially centrally disposed in  FIG. 8 . The sidewalls  103  are preferably configured to have a smaller distance to each other in a lower area than in an area higher up. It is thereby possible to insert the stator member  10  in a simple and tilt-free manner. 
         [0075]    According to a second embodiment of the invention shown in  FIG. 9 , the holding member  100 ′ has sidewalls  103 , which extend over an entire extension of at least the stator member insertion portion  109  and end at the same height, and preferably such like the at least two attachment portions  106 . At least in sections, connections in the shape of webs  111  are configured between the sidewalls  103 ′, which webs, on the one hand, impart a higher rigidity to the holding member. On the other hand, they keep possibly installed cables  3  and/or lines  4  on the bottom of the above described reception space, such that, during installing or uninstalling the stator  1  from the carrying profile  40 , they do not slip easily out of the carrying profile  40  or are damaged in the process. The webs  111  are preferably configured integrally with the sidewalls  103 . 
         [0076]    Instead of the webs  111 , a complete covering may be provided such that at least the stator member  10  is entirely enclosed. Such a complete covering may be formed by means of a cover part, which is preferably clipped onto the holding member  100 . 
         [0077]    In addition to sliding door drives, the stator illustrated herein is applicable with linear motors, which are utilized as a drive system for telescopic sliding doors, curved sliding doors, revolving doors, folding leaf doors, and mobile partitioning walls or the like. 
         [0078]    Thus, while there have shown and described and pointed out fundamental novel features of the invention as applied to a preferred embodiment thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices illustrated, and in their operation, may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto.