Connector arrangement for compact servomotor

A plug connector device (11, FIG. 2) for medium voltage (e.g. 220 volts) compact servomotors has a power plug unit (16) and a control signal plug unit (17), each with connectable/disconnectable outer and inner plugs (49,48 and 52,51), the units lying in a single connector housing that is supported around a wire-passing aperture (14) in a motor housing part (13) and that pivots to different angular positions.

BACKGROUND OF THE INVENTION

Current compact medium voltage (e.g. 220 volts) servomotors are connected to two separate pin-and-socket type connectors, one for power and the other for control signals. The two connectors which are separately mounted, occupy considerable space, especially compared to the compact servomotor itself. It has been suggested that the two connectors be arranged coaxially, but this would add considerable expense. A low cost and compact connector arrangement that connected power and control signal cable conductors to corresponding wires of a compact servomotor, using separate mateable plugs for isolation, would be of value. It also would be of value if the cables could extend in any of a plurality of directions from the motor.

SUMMARY OF THE INVENTION

In accordance with one embodiment of the invention, a compact and angularly adjustable servomotor system is provided that receives power and signal currents though wires extending though a wire-passing aperture in the motor housing, such currents passing though corresponding power and control signal cables and mateable connectors to the wires. The system includes a connector housing that has an inner end portion with an opening that is aligned with the wire aperture in the motor housing. The housing also has an outer end portion into which power and control signal cables extend. The shell holds mating pin-and-socket type inner and outer plugs of both a power plug unit and a control signal plug unit. The shell includes upper and lower metal shell parts that can be separated to install, remove, connect, and disconnect the plugs, and the shell halves then can be held together.

The shell is mounted on the motor housing so the shell can be pivoted to a selected position about the vertical axis of the wire-passing aperture in the motor housing, to allow the cables to extend in a desired horizontal direction from the shell. In one system, an adaptor is mounted on the motor housing and has an adaptor bore aligned with the wire-passing aperture. The lower shell half has a tubular portion that extends down into the adaptor bore. The tubular portion has a radially-outward flange at its lower end. A screw that extends though a threaded hole in the adaptor, has a screw end that moves over the flange to trap the shell in place on the adaptor and motor housing. The screw can be loosened slightly so the shell can be turned about the axis to extend in a desired direction, with the screw then tightened again to fix the direction.

In another system, screw holes are formed in the motor housing around the wire-passing aperture. The inner end of the lower shell has corresponding screw holes, so the shell can be fixed to the motor housing by screws. The screw holes are uniformly angularly spaced about the wire passing aperture, so the shell can be fastened at any one of a plurality of angular positions.

In another design, a clip ring is used to fasten a downwardly-extending tubular portion of the inner end of the lower housing shell to an adaptor mounted on the motor housing. The clip ring is installed in an adaptor groove. Radially inward projections of the clip ring pass through slots in the adaptor groove and enter portions of a groove in the tubular portion of the lower shell half. The clip ring has a projection that holds the shell in a selected angular position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Limited Description

FIG. 1shows a servo motor system10of the present invention, which includes a compact servo motor with a motor housing13, and a plug connector device11attached to the motor housing. The plug connector device11guides a power cable38and a control signal cable39so they extend to, and so they releasable connect to, corresponding wires of the motor. The plug connector device can be pivoted about a vertical axis70on the motor housing to guide the cables so they extend in any one of a group of compass directions (directions angled about the axis). Such pivoting about axis70is indicate by arrows A.

FIG. 2shows that the plug connector device includes a metal connector housing15having a lower housing part or shell28and an upper housing part, or shell, or cover29. The connector housing has a small vertical thickness, a larger width, and a still larger length in the direction of arrows I, O. The housing has an outer end72from which the cables extend, and has an inner end74that connects to the motor housing13. The motor housing has a bushing or aperture14. Power and control signal wires indicated at76and78extend though the aperture. Inward and outward directions are indicated by arrows I and O, while upward and downward directions are indicated by arrows U and D. The system can be used in any orientation, and the arrows and descriptions of “up”, “down”, etc. are made only to help describe the system.

A power plug unit16and a control signal plug unit17lie in the connector housing15. The power plug unit16includes inner and outer power plugs48,49that connect by engagement of pin and socket contacts of the plugs. Similarly, the control signal plug unit17includes inner and outer control signal plugs51,52with pin and socket contacts.FIGS. 5A and 5Bshow the pins of the outer plug connectors.FIG. 2shows that the cables have power and control signal conductors80,82that connect to contacts of the outer plugs49,52. The power and signal wires76,78connect to contacts of the inner plugs48,51. The inner and outer plugs of each unit are preferably mated before the units are installed in the lower shell28and the shells are connected together. The shells are shown connected together by screws that pass though three holes79.

The motor housing13shown inFIG. 2forms the aperture14though which the power and control signal wires extend. The axis70lies on the axis of the aperture. The lower shell has an inner end or end portion84that must be mounted on the motor housing13. The lower shell has an opening18at its inner end that must lie aligned with the motor housing aperture. As mentioned above, it is highly desirable that the connector housing15be capable of pivoting about the axis70to different angular positions.

As shown inFIG. 3A, applicant provides an adaptor12which is mounted on the motor housing13. The motor housing is formed with four threaded holes that receive four screws21that pass though adaptor holes. The adaptor has a bore19that is aligned with the motor housing aperture. As shown inFIG. 4, the lower shell has a tubular part90and has a radially outwardly-extending (with respect to axis70) flange35whose upper surface forms an upwardly-facing shoulder.FIG. 3Ashows that the adaptor has a pair of projections23,24at one side of its bore and has a screw26at its opposite side. With the screw loose, the lower shell tubular part can be moved down into the adaptor bore19. Then, as shown inFIG. 4, the screw26is tightened to fix the connector housing15in place. The screw can be loosened slightly to allow the connector housing to be turned to extend at a different angle, and the screw then can be tightened to fix that angle. The general arrangement of two projections and a screw is known for holding parts together, but has not been used to hold a plug connector device to an adaptor on an apparatus such as a motor.

FIG. 11shows that a metal shield243is placed between the power and plug units lying in the connector housing.

FIG. 7shows another embodiment of the invention wherein the lower shell128has an inner end184that is mounted on the motor housing113without an adaptor. The motor housing is formed with threaded holes177, and screws178that pass through holes in lower walls of the lower shell. The screws are threadably engaged with the threaded holes177of the motor housing. The holes in the motor housing and the screw-receiving holes in the lower shell are uniformly spaced about the axis70of the wire-passing aperture in the motor housing. This allows the plug connector housing115to be installed in any one of a plurality of angular orientations about the axis70. The particular system shown has four holes in the motor housing and four holes in the inner end of the lower shell, which allows rotating to four positions spaced 90° apart about the axis70.

FIG. 8illustrates another system wherein an adaptor212is mounted by screws onto the motor housing213, and the lower shell inner end284is mounted on the adaptor by a clamping ring or clip280. The clip is preferably formed of stainless steel. As shown inFIG. 10B, the clip has a pair of widened ends281that can be resiliently spread apart. The clip also has a middle or eye284with a hole and with at least one latching tooth286.

As shown inFIG. 12, the clip is first installed in a radially outer groove300in the adaptor212. The lower shell inner end has a downwardly-extending tubular part302that fits into a bore304in the adaptor. The tubular part has an inner groove306. The adaptor groove has three slots289,289,288and the clip widened ends281and tooth286each projects through one of the slots into the inner groove306. In this way, the clip prevents the lower shell inner end tubular part from pulling up, so long as the clip is fully installed.

The inner groove306, which lies on the tubular part that extends from the lower shell, has a plurality of indentations, shown at320inFIG. 10B. When the clip is fully installed, the latching tooth286lies in one of the indentations and resists pivoting of the plug connector housing about the axis70. However, the plug connector housing can be forced to rotate, and the clip serves as a spring-biased latch that holds the plug connector housing in the position to which it is pivoted.

DETAILED DESCRIPTION

In accordance withFIG. 1, in a first exemplary embodiment, a plug connector device11is attached via an adapter12to a housing part13of an undepicted compact servomotor so as to be rotatable in the direction of double arrow A and as well as detachable. Plug connector device11, as can be seen inFIG. 2, has a first plug connector unit16for the operating voltage of the servomotor and a second plug connector unit17for the control signals of the servomotor, both units being accommodated in a single, joint connector housing15. Both motor housing part13as well as joint connector housing15have a bushing14,18for the electrical leads to the servomotor, a through bore hole19of adapter12being arranged between bushings14and18, preferably in rough alignment with them.

Adapter12has the shape of a roughly square, flat disk that is furnished with through bore hole19, the disk in the exemplary embodiment depicted being attached by four screws21to an exterior surface22of motor housing part13. It is obvious that adapter12can also be molded on motor housing part13. Adapter12, which occupies a significant portion of relevant exterior surface22of motor housing part13, is provided on the interior circumference of through bore hole19with two radial projections23and24, whose radial interior surfaces are also circular. Two radial projections23and24are spaced at an acute angle with respect to the radius of the bore hole; in addition, they are relatively narrow. Their width is less than the axial dimensions of the interior circumference of through bore hole19and of the width of adapter12, their surfaces aligning with the surface of the adapter. A fixing screw26in the form of a setscrew is radially introduced so as to be able to be screwed in and out from outside and is situated roughly diametrically opposite two adjoining radial projections23and24, i.e., from their midpoint.

Connector housing15is in two parts, i.e., it is composed of a lower shell28and a cover shell29, cover shell29being able to be detachably screwed onto lower shell28. Facing away from cover shell29, lower shell28around its bushing18has an annular projection31, which is provided with an annular undercut32(FIG. 4). The exterior diameter of annular projection31is the same as or smaller than the remaining interior diameter between radial projections23and24, on the one hand, and the interior circumferential area on unscrewed fixing screw26of adapter12, on the other hand. In this way, in accordance withFIG. 3B, annular projection31of lower shell28of connector housing15can be inserted into adapter12in the direction of arrow B. If, after this insertion, as depicted inFIG. 3B, fixing screw26is screwed into undercut32so as to engage, annular projection31and therefore lower shell28is displaced in the direction of arrow C toward two; radial projections23and24, which contact annular undercut32on annular projection31. In this way, lower shell28is held at three locations within annular undercut32of annular projection31, namely at both radial projections23and24, on the one hand, and at fixing screw26, situated roughly diametrically opposite, on the other hand. Annular undercut32on annular projection31, like both radial projections23and24and like the tip of fixing screw26, is provided with a beveled surface33,34, by which annular projection31is pressed toward exterior surface22of motor housing part13, which is covered with a sealing ring35; in this manner, a tightly sealed connection of housing lower shell28on motor housing part13is assured via its annular projection31. When fixing screw26is loosened, it is possible without damaging the seal to rotate lower shell28and therefore entire connector housing15with respect to motor housing part13in the direction of the aforementioned double arrow A due to the aforementioned three-point connection that engages from different sides radially.

Lower shell28of connector housing15has an elongated shape that is rounded in front and rectangular in the rear, as can be seen inFIGS. 1 through 3. Annular projection31is arranged in the area of the rounded shape in front, whereas in the area of the rectangular edge in the rear, two semicircular cutouts36and37are formed next to each other, into which cable clamps41,42are inserted for the feeding through of two adjacent cables38and39.

Lower shell28of connector housing15, which is molded out of plastic and/or metal, is provided with a shielding separating wall43in the longitudinal direction and, on both sides of this shielding separating wall43in two receiving spaces44and45thus remaining, with front and rear fixing projections46and47. Into these receiving spaces44and45, first plug connector unit16and second plug connector unit17are inserted and supported (FIG. 2) in a joined state that is constituted by one socket plug48,51and one pin plug49,52. It is obvious that, although it is not depicted, the likewise undepicted wires of both cables38and39are joined to the pin plugs49,52in question, whereas the other ends of first and second plug connector units16,17, depicted here as socket plugs48,51, are joined to likewise undepicted electrical leads for the operating voltage and the control signals to the servomotor.

First and second plug connector units16and17are mounted within the connector housing15in the following manner. If the undepicted wires leading from the servomotor are pulled out through bushing14in motor housing part13, they can be joined to socket plug48of first plug connector unit16and to socket plug51of second plug connector unit17. It is obvious that in this state, adapter12is already mounted and the wires are led out through adapter12. It is then possible to fixedly connect these wires to socket plug48,51. Thereafter, socket plugs48and51, in sequence, are pushed through sufficiently large bushing18of connector housing15, i.e., from its lower shell28. After pin plugs49,52are connected to the wires of relevant cables38,39, the former are connected to respective socket plugs.48,51and are introduced into the above-mentioned receptacle spaces44,45. In this assembly step or in a preceding one, lower shell28can be joined to adapter12in the manner depicted above. Thereafter, according toFIG. 2, cover shell29is placed onto lower shell28and is screwed down at, for example, three points. In this context, clamps41and42, i.e., cables38and39, are supported in clamping fashion between lower shell28and cover shell29of connector housing15. It is clear that socket plugs48and/or51and pin plugs49and/or52can be exchanged.

In the exemplary embodiment depicted inFIGS. 1 through 6, undepicted latching means can be provided on connector housing15, for example, on annular projection31and on adapter12, in order to achieve preferential positions of, for example, 15°-, 30°-, 45°-steps or the like, when connector housing15is rotated with respect to motor housing part13in accordance with double arrow A.

According toFIGS. 5A and 5B, socket and pin plugs48,51and49,52, are provided with a latching catch and a latching recess56,57, and58,59. In addition, in the joined state, a planar exterior contour results of two plugs48and51,59and52, which are joined to form first plug connector unit16and second plug connector unit17, respectively. To separate the plugs, it is possible to undo the latching connection56through59by applying tensile force.

FIG. 6shows a socket plug51for the control signal wires, socket plug51being configured in two parts with respect to its insulation housing. An interior part61is provided with an upper and a lower row of axial, undercut channels62,63, which are open towards the upper and lower sides over a width of less than the channel diameter. Into these undercut channels62and63it is possible to insert socket contacts64and65from above and from below. In this context, the axially central undercut assures that socket contacts64,65are axially unmovable. This interior part61that is equipped with the socket contacts can then be inserted into a hollow insulating body66and held, for example, in a clamping or latching fashion. It is clear that not only socket plug51for the control signal contacts but also socket plug48for the operating voltage contacts can be configured in this manner. In addition, pin contacts49,52can also be manufactured in this way.

In the second exemplary embodiment, depicted inFIG. 7, of a plug connector device111, which is attached to a motor housing part113via an adapter112, connector housing115is externally configured similar to connector housing15in accordance with the first exemplary embodiment, i.e., it is composed of a lower shell128and a cover shell29.

In this connector housing115, lower sh-ell128provides space for a total of four plug connector units116,117,117′ and117″, which are joined to two cables138and139at the input side. Whereas in the first exemplary embodiment in addition to plug connector unit16(here116) for the voltage supply only one plug connector unit17was provided for the signal lead, in this second exemplary embodiment three plug connector units117,117′,117″ are provided for the signal lead. Cover shell129is provided with a seal171. In addition, cable clamps141and142are moved within lower shell128, whereas on the exterior side guideway half shells172and173are provided, which support cables138,139using crimping sleeves174and rubber seals175.

A further difference between this second exemplary embodiment (FIG. 7) and the first exemplary embodiment (FIG. 2) lies in the fact that adapter112is molded on lower shell128of plug connector unit111and is provided with a total of four bore holes177for attaching adapter112and lower shell128to motor housing part113in its threaded bore hole178. Bore holes177in molded adapter112are accessible from the base of lower shell128. In other words, connector housing115, in the open state and before the insertion of plug connector units116,117,1177and117″, can be fixedly screwed on motor housing part113. Because in this variant four through bore holes177are provided in adapter112and four threaded bore holes178are provided in motor housing part113, in each case an identical distance from each other, connector housing115is fixedly screwed in such a manner that, although it is non-rotatable, nevertheless the position of connector housing115can be selected in positions 0°, 90°, 180°, 270°, and 360° with respect to motor housing part113.

Plug connector units116,117,117′,117″ are selected in accordance with the representations inFIGS. 5A,5B, and6, with the difference that the plug connector units for the signal leads do not have 12 poles but rather in the exemplary embodiment only have six poles, but for that reason are provided in threes.

In theFIGS. 8 to 10, a plug connector unit211according to a third exemplary embodiment is depicted. In this exemplary embodiment, the interior space of connector housing215is configured in accordance with connector housing115and consequently is furnished with a total of four plug connector units216,217,217′,217″. The further interior configuration of connector housing215corresponds to that of connector housing115, such as seal271, guideway half shells272,273, crimping sleeves274,275, rubber seals275, etc.

In this third exemplary embodiment of the present invention, connector housing215, similar to connector housing15of the first exemplary embodiment, is rotatably supported on the motor housing part213so as to be able to be latched in variously stepped angular positions. For this purpose, a baseplate279of an adapter212is fixedly screwed on motor housing part213using four screws. In addition, the lower side of lower shell228of connector housing215is provided with an annular projection231, whose exterior diameter is smaller than the interior diameter of adapter212and therefore can be inserted into the adapter.

To achieve the axial, fixed, and rotatable connection of annular projection231of connector housing216on adapter212that is attached to motor housing part213, a clamping ring280like a Seeger circlip ring is provided (FIGS. 10A and 10B). Clamping ring280is open on one side and has on both of its free ends a radially inwardly projecting widened area281, whose interior surface on the transition to the annular area282of clamping ring280is provided with a spring-action step283. The center of clamping ring280is configured as an eye284having a bore hole285, eye284having a latch, or latching tooth286, that is oriented radially towards the interior. For receiving clamping ring280, annular projection231, which axially projects from lower shell228, has an exterior annular groove287, which on three circumferential areas is provided with a central cutout288and two end-side cutouts289from the base of annular groove287extending towards the interior. Central cutout288functions to permit the penetration of an interior area of eye284, that is provided with latching tooth286, whereas two end-side cutouts289function to permit the penetration of the widened area281that is provided with step283.

Inserting clamping ring280into annular groove287is accomplished from the position depicted inFIG. 8in the direction of arrow D, the interior edge of widened area281initially sliding by on the base of the areas of annular groove287in question and initially pre-latching in end-side cutout289(FIG. 10B). In this pre-latching position widened areas281in end-side cutouts289are found in a pre-latched condition, such that steps283, due to the radial biasing of the annular clamping ring areas, latch behind the interior edge of end-side cutout289. In this pre-latching position, both latching tooth286as well as the interior areas of widened areas281are radially set back from the interior circumference of annular projection231of lower shell228. Therefore, in this pre-latching position, clamping ring280cannot engage in adapter212so that lower shell228can be axially inserted over adapter212and can be covered in the circumferential direction with respect to the adapter.

Adapter212, whose cylindrical part291, projecting from baseplate279, engages in annular projection231, has an annular groove292, whose base is provided with a toothing293. If the end face of annular projection231rests on baseplate279, which is screwed fixedly to motor housing part213, then annular groove292that is provided with toothing293is located at the axial height of and is radially aligned with annular groove287of annular projection231, and with its cutout288and289. If clamping ring280from its pre-latching position (FIG. 10B) is further displaced in the direction of arrow D, then both widened areas281arrive at toothing293in annular groove292, i.e., move out of the latching connection in the end-side cutout289of annular projection231. At the same time, latching tooth286of eye284arrives in toothing293of cylindrical part291, so that connector housing215is fixedly secured on adapter212so as to be nonrotatable (FIG. 10A).

It is then possible once again to rotate connector housing215with respect to adapter212, i.e., motor housing part213, if clamping ring280is pulled back opposite the direction of arrow D into its pre-latching position as depicted inFIG. 10B, or preferably if by rotating connector housing215using a great expenditure of force, clamping ring280pulls back independently. In accordance with the selected toothing, a rotation can be carried out in stepwise fashion in virtually any angular position of connector housing215with respect to motor housing part213.

Beneath annular groove292that is provided with toothing293, adapter212has a further annular groove, that is not depicted in detail, for receiving one or more sealing rings.

FIG. 11depicts one variant in which a grounding clip295is attached to metal lower shell228and is configured such that by correspondingly designing one plug249of plug connector unit216, a horizontal grounding pin296comes into direct contact with grounding clip295when plug connector unit216is inserted.

Furthermore,FIG. 11also shows a shielding wall243, which is either fixedly provided or can be placed in two different positions in lower shell228. In this context, it is possible to arrange shielding wall243either in the position depicted inFIG. 11, i.e., between second plug connector unit217′ and third plug connector unit217″ and/or between third plug connector unit217″ and plug connector unit216. The measures cited with regard toFIG. 11can also be undertaken with respect to lower shell128in accordance withFIG. 7.

In the exemplary embodiments of plug connector device11,111,211depicted in the drawing, connector housing15,115,215is subdivided horizontally into a lower shell28,128,228and a cover shell29,129,229. According to another undepicted exemplary embodiment of the present invention, the connector housing is subdivided in a vertical longitudinal plane such that the two connector housing parts, configured symmetrically or asymmetrically, can be brought together in the plane of the adapter or of the exterior surface of motor housing part13,113,213. In this context, the plug connector units are preferably accommodated in one of the two connector housing parts, whereas the other connector housing part is empty and, if necessary, receives the area of the plug connector units that extends beyond the separating plane. In this exemplar embodiment, the adapter on its exterior circumferential side is provided with an annular undercut on one annular exterior circumference, into and over which the two connector housing parts can be slipped from the radial sides of the adapter. Both connector housing parts are rotatably but not detachably supported on the adapter.

In a further variant of this exemplary embodiment of the connector housing that is subdivided in a vertical plane, the plug connector units are either arranged, as in the depicted exemplary embodiments, in one horizontal plane next to each other, or they are arranged within one of the two connector housing parts one on top of the other, a horizontal separating wall that functions as an electromagnetic shield being arranged between the two plug connector units that are disposed one on top of the other.