Patent Publication Number: US-2019195402-A1

Title: Connection device, in particular for the realization of a rotary connection for a connection component

Description:
The invention relates to a connection device, in particular for implementing a rotary connection for a connection component, having a housing, which has a connection point for a fluid-conveying line, such as a pneumatic line, and a bearing arrangement, by means of which a hollow shaft or axis-shaped connector part is mounted so as to be rotatable relative to the housing and which forms a further connection point for the relevant further connection component. 
     Such devices are used, for example, for connecting connection components in the form of two hose lines or for connecting a hose line to a fixed line connection, wherein bending or torsional loads possibly occurring on the line components forming the line sections are reduced or avoided due to the rotatability of the connection points provided by the bearing arrangement. Different media, such as gases or liquids, can be routed through the line sections. 
     A connection device of the type mentioned above is known from DE 20 2009 005 674 U1. In this device the bearing arrangement is formed by an inner wall section of a hollow shaft-like connector part forming a slide bearing, which connector part comprises a housing part formed by a rotary body. With this arrangement, no sufficient stability of the connection area between the housing and the rotatable connector part, in particular no operational reliability for longitudinal forces acting between the connector parts, can be achieved because of the axial displacement permitted by the slide bearing section. 
     Based on this prior art, the invention addresses the problem of providing a generic connection device, which is characterized by a high mechanical stability in a compact and media-tight design. 
     According to the invention, this problem is solved by a connection device having the features of claim  1  in its entirety. 
     According to the characterizing part of claim  1 , a significant feature of the invention is that the bearing arrangement comprises at least one roller bearing, the outside of the outer race of which is in contact with the housing and the outside of the inner race of which bears on the rotatable connector part. With this arrangement, where the inner race is secured on the rotatable connector part, which inner race is preferably secured to the rotatable connector part by a pressing process, such that it cannot be displaced axially, a rotary bearing between the housing and connector part can be formed, which bearing is particularly robust with respect to axial forces and bending forces. 
     In particularly advantageous exemplary embodiments, the bearing arrangement has, in addition to the roller bearing, a slide bearing, whose inner peripheral side encompasses the rotatable connector part, the end face of which rests against a press-fit ring of the housing, which encompasses the end of the connector part while maintaining radial and axial spacing, the slide bearing otherwise being mounted in a spacer ring. Two axially spaced bearings result in a particularly high bending strength of the bearing, wherein the slide bearing held in a spacer ring is secured in the axial direction by the frontal contact against a press-fit ring firmly attached to the housing. 
     A ball bearing can advantageously be provided as a roller bearing. 
     In advantageous exemplary embodiments, the spacer ring is radially sealed with the slide bearing facing the housing, in particular using an O-ring, and rests against a further seal in the axial direction, in particular in the form of a shaft seal, which encompasses the connector part and which has a contact surface for a spacer ring opposite the spacing ring, which engages with the outer race of the ball bearing at the end face thereof. This arrangement ensures a permanently high media tightness of the rotatable connection between the housing and connector part. 
     The arrangement can advantageously be made such that the spacing ring is angular viewed in cross-section, is in contact with the further seal in the area of one of its legs and has an axial spacing to a radially protruding bearing shoulder of the connector part opposite the seal, with which shoulder the connector part rests against the inner race of the roller bearing at the end face. In this way, the spacer ring is axially secured to the housing between the press-fit ring and the spacing ring. 
     In advantageous exemplary embodiments, the housing is formed of two parts, wherein one housing part has the bearing arrangement and the other housing part has the associated connection point and wherein the slide bearing of the press-fit ring rests at least partially against the distance ring in the area of the connection of the two housing parts. 
     Furthermore, the connection point of the rotatably mounted connector part, which is axially fixed in the housing by means of the bearing arrangement, can protrude from the housing with its associated connection point, wherein at the location of the penetration of the connector part, a ring opening is created between the housing and connector part, which serves for the penetration of parts of the connection component, the end faces of which rest against the inner race of the roller bearing and can be firmly attached to the connector part. This connection can advantageously be formed by a screw connection. 
     Advantageously, the arrangement may be made such that a further sealing ring is arranged between the press-fit ring and the further housing part and also on the further housing part in the area of the transition to the connection point for the fluid-conveying line. 
     According to claim  9 , the subject matter of the invention also relates to a connection arrangement comprising at least one connection device according to one of the claims  1  to  8  and a connection component coupled thereto, which is connected to the connection device in a fluid-conveying manner and can move relative to the same by means of the bearing arrangement and the connector part mounted rotatably to that extent. 
     The housing structure of the connection component associated with this connection arrangement can have a linear or angular design and may have a quick coupling for supporting a further fluid-conveying line at its free end. Such a quick coupling may be designed in the known manner of a collet device actuatable by means of a clamping nut. 
     Below the invention is explained in detail with reference to exemplary embodiments shown in the drawing. 
    
    
     
       In the drawings: 
         FIG. 1  shows a perspective oblique view of an exemplary embodiment of the connection device according to the invention; 
         FIG. 2  shows a longitudinal section through one half of the exemplary embodiment; 
         FIG. 3  shows a perspective oblique view of the exemplary embodiment of the connection device having a connection component of linear design connected thereto; 
         FIG. 4  shows a longitudinal section of the content shown in  FIG. 3 . 
         FIG. 5  shows a perspective oblique view of the exemplary embodiment of the connection device having a connection component of angular design connected thereto; 
         FIG. 6  shows a central angle section of the content shown in  FIG. 5 . 
     
    
    
       FIGS. 1 and 2  show an exemplary embodiment of the connection device according to the invention without the connection component connected thereto. The device has a housing  1 , which consists of a metallic material, such as a bronze alloy, and is composed of two housing parts  3  and  5 . A connection point  7  is formed at the end of the housing part  3  located on the left in  FIGS. 1 and 2 , which has a male thread  9  for a screw connection with a connection component not shown. The housing part  3  designed as a hollow body has a coaxial through hole  11 , which opens to the outside at the connection point  7  and widens to approximately twice the diameter at approximately half the length of the housing part  3  forming a shoulder  13  in a radial plane. In the extended end part of the drilled hole  11 , the end part  15  of the housing part  3 , the outer circumference of which is extended, has a hexagon head  17 . 
     The second housing part  5  has the shape of a circular cylindrical sleeve with a through-opening  21  concentric to the axis  19 , which is located at a radially inward projecting end rim  23  of the tubular body of the housing part  5  at the end that is on the right in  FIGS. 1 and 2 . At the end area facing the first housing part  3 , the housing part  5  is fixedly attached at  25  by pressing to the end part  15  of the first housing part  3 , which extends over the end area. At the opposite end of the connection point  7 , a second connection point is formed on a connector part in the form of a hollow shaft  24 , which is rotatably mounted in the housing  1  and forms the fluid-conveying continuation of the drilled hole  11  of the first housing part  3 . At the hollow shaft  24 , the connection point for the connecting component, which again is not shown, is formed by a male thread  27 , which is located on the end section of the hollow shaft  24  extending out of the housing part  5 . The diameter of the drilled hole  21  of the housing part  5  provided for the passage of the hollow shaft  24  is dimensioned such that an annular gap  29  is formed between the hollow shaft  24  and the end rim  23  of the housing part  5 . 
     The hollow shaft  24 , which continues the flow path of the drilled hole  11  essentially without offset, is rotatably mounted in the second housing part  5  by means of a bearing arrangement  31 , which is formed of a package of several components, which package is arranged on the end portion of the hollow shaft  24  mounted inside the housing part  5  and which extends between the hollow shaft  24  and the shell  33  of the housing part  5  substantially over the entire axial length of the latter. In sequence in  FIG. 2  from right to left, the component package of the bearing arrangement  31  has a ball bearing  35 , an angular spacing ring  37 , a shaft seal  39 , an O-ring  41  and a slide bearing  43 , wherein the shaft seal  39 , the O-ring  41  and the slide bearing  43  are mounted in a spacer ring  45 . In approximately the central area of the longitudinal section of the hollow shaft  24  supporting the bearing arrangement  31 , the hollow shaft has a radially outward projecting shoulder in the form of a ring  47  having a square cross-section. To manufacture the connection device, the procedure is such that the hollow shaft  24 , including the package of the bearing arrangement  31 , is installed in the housing part  5 , before the housing  1  is closed by pressing the housing parts  3  and  5  together. To this end, first hollow shaft  24  and ball bearings  35  are pressed together such that the inner race  49  of the latter rests against the ring  47  of the hollow shaft  24 . On the opposite side of the ring  47 , the other components of the bearing arrangement  31  are preassembled on the hollow shaft  24 , after which they are inserted together with the package of the bearing arrangement  31  from the open side of the housing part  5 . In doing so, the radially outer leg  51  of the angular spacing ring  37  comes to rest against a shoulder  53  of the inside of the shell  33  and to rest against the outer race  55  of the ball bearing  35 . In this position of the spacing ring  37  its radially inside leg is located at an axial distance from the radially protruding ring  47  of the hollow shaft  24 . The spacer ring  45  with the associated shaft seal  39 , the O-ring  41  and the slide bearing  43  rest against the spacing ring  37  at the side facing away from the ring  47 . 
     Before closing the housing  1  by pressing the housing parts  3  and  5  together at  25 , an O-ring  59  and a press-fit ring  61  are inserted on the inside of the end part  15 , the side of the press-in ring facing away from the bearing arrangement  31  resting against the shoulder  13  of the housing part  3 . On the side facing the bearing arrangement  31 , the press-fit ring  61  has an annular surface  63  in a radial plane for contact on the spacer ring  45  and the slide bearing  43 . A coaxial recess  65  adjoins the radially inner end of the annular surface  63 , which recess forms a free space for the shaft end  67  of the hollow shaft  24 , into which free space the shaft  24  extends without contact with the press-fit ring  61  when the housing  1  is closed. For this purpose, the press-fit ring  61  is fixed in position by the closing process of the housing  1 . As shown in  FIG. 2 , when the housing  1  is closed, the bearing arrangement  31  is positively secured axially between the annular surface  63  of the press-fit ring  61  and the opening rim  23  of the housing part  5 . The slide bearing  43 , which is secured in the spacer ring  45  by the abutting annular surface  63  of the press-fit ring  61 , is formed of a material having a high abrasion resistance and a low coefficient of friction, in the present example of a thermoplastic material, such as polyoxymethylene (POM), a material characterized by low coefficient of friction and dimensional stability. Due to the free gap between the radially protruding ring  47  of the shaft  24  and the spacing ring  37  and due to the recess  65  in the press-fit ring  61 , into which the shaft end  67  extends without contact thereby forming a gap, the hollow shaft  24  can be easily rotated in the housing  1 . 
       FIGS. 3 and 4  show the housing  1  in connection with a connection component  71 , which is connected to the connection point formed by the free end of the hollow shaft  24  by screwing it onto the male thread  27 . The connection component  71  has a hollow body  72  with a coaxial inner channel  73 , which continues the fluid path of the hollow shaft  24  when connected. As  FIG. 4  shows, the hollow body  72  at the end facing the housing  1  has a section  75  of reduced wall thickness, which, in the screwed-on state shown in  FIG. 4 , extends into the annular gap  29  at the passage opening  21  of the housing part  5  and rests against the inner race  49  of the ball bearing  35 . The channel  73  has a constriction in the form of a radially inwardly protruding ring  77 , which has a flat contact surface  79  on one side, which abuts the end of the hollow shaft  24  in the screwed-on state ( FIG. 4 ). An inclined surface  81 , against which the end of a conduit connected by means of the connection component  71 , such as a hose line, rests, forms the opposite side of the ring  77 , which surface extends through an O-ring  83 . The connection component  71  has a quick coupling  85  for the attachment of such a hose, which quick coupling is formed by a collet device of conventional design in the example shown, which has a basket of flexible chuck levers  87 , which can be actuated by a clamping sleeve  88  for the clamping operation. 
       FIGS. 5 and 6  show a modified example, in which an angular connection component  89  is connected at the connection point formed by the free end of the hollow shaft  24 , which component continues the fluid connection in the direction of an axis  91 , which runs at right angles to the axis  19  of the housing  1 . The connection component  89  has a connection body  92 , which, like the hollow body  72  of the connection component  71 , has an inner channel  73  as a continuation of the fluid path of the hollow shaft  24 . Like the hollow body  72 , the connecting body  92  is screwed to the male thread  27  of the hollow shaft  24 , wherein, as in the previous example, an end section  75  passes through the passage opening  21  in the housing part  3  and rests against the inner race  49  of the ball bearing  35 . The channel  73  in the connection body  92  has a branch coaxial with the axis  91 , having a female thread  93  to which a threaded ring  94  is screwed, to which in turn, the hollow body  72  of the quick coupling  85  is screwed.