Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims priority to German Patent Application No. 10349773.0, filed Oct. 24, 2003, which application is herein expressly incorporated by reference. 
   BACKGROUND OF THE INVENTION 
   The invention relates to a drive and, more particularly, to an agricultural machinery driveline with a drive housing and a rotatably supported first shaft. The first shaft comprises longitudinal teeth to connect to a second shaft, for example to a shaft journal or a driveshaft. The longitudinal teeth of the first shaft and the longitudinal teeth of the second shaft, together, form a splined connection to transmit torque between the first shaft and the second shaft. 
   In order to avoid symptoms of wear in such prior art drives, the splined connection is greased. However, it has been found in practice that this measure is not always sufficient and that the splined connection is worn prematurely. 
   SUMMARY OF THE INVENTION 
   It is the object of the present invention to propose a drive of the initially mentioned type whose splined connection has a longer service life. 
   In accordance with the invention, a drive in an agricultural machinery driveline includes a drive housing. The drive housing forms an interior and is at least partially filled with a lubricant. A first shaft is rotatably supported in the drive housing around a longitudinal axis. The first shaft extends out of the interior. The first shaft has first longitudinal teeth to connect, in a rotationally fast way, to a second shaft. The second shaft has second longitudinal teeth formed to complement the first longitudinal teeth. One of the two shafts includes a receiving bore arranged coaxially relative to the longitudinal axis. The bore includes one of the shaft&#39;s longitudinal teeth into which the other shaft&#39;s longitudinal teeth are inserted. A lubricant guiding mechanism is in the first shaft or in the drive housing. The guiding mechanism, in the connected condition of the two shafts, connects the interior to the receiving bore. A valve is integrated into the guiding mechanism. The valve can be set between a closed position, to close the lubricant guiding mechanism, and an open position. The valve is transferred from the closed position into the open position by connecting the first shaft to the second shaft. 
   This solution is advantageous since the splined connection is integrated into the lubrication circuit of the drive. The valve ensures that a connection exist between the interior of the drive housing and the receiving bore only if the first shaft and the second shaft are connected to one another. Thus, the uncontrolled escape of lubricant is avoided when the shafts are disconnected. 
   The receiving bore is preferably arranged in the first shaft. Accordingly, the second shaft is inserted into the receiving bore. 
   According to a further embodiment, the valve is designed to close automatically. The valve includes a valve body which is displaceable between a closed position, in which it closes a valve bore, and an open position. Furthermore, the valve body is designed so that, when the second bore is received in the receiving bore, the valve body is supported in the bore and held in the open position. 
   When the shaft journal is introduced into the receiving bore, the shaft journal abuts the valve body. As this occurs, the shaft journal moves the valve body out of the closed position into the open position. 
   The lubricant guiding mechanism can include a bore in the first shaft. The valve is incorporated into the bore. The valve body projects beyond an end face of the first shaft towards the second shaft. The valve body is arranged so that, in the inserted condition, the valve body comes into contact with the second shaft and is held by the second shaft in the open position. 
   Furthermore, the receiving bore can form an inner circumferential face. The lubricant guiding mechanism extends transversely to the longitudinal axis from the interior of the drive housing to the inner circumferential face. 
   According to a further embodiment, a through-bore is arranged in the first shaft. The through-bore forms the receiving bore. The valve is arranged in a bearing bore of the drive housing. The bearing bore serves to receive a bearing axle to support the second shaft. The valve includes a valve body which is displaceable between a closed position and an open position. The valve is loaded towards the closed position where it closes a valve bore. The valve body is designed so that, when the bearing axle is received in the bearing bore, the valve body is supported in the bearing bore and held in the open position. 
   The valve preferably includes a housing and a valve body. The valve body is adjustable in a valve bore, in the form of a through-bore of the housing, along an open position and a closed position. The valve bore has a first bore portion and a second bore portion. The second bore portion diameter is reduced relative to the first bore portion. The valve body is guided in the first bore portion and has an out-of-round cross-section. The diameter of the valve body is smaller inside the second bore portion than the diameter of the second bore portion. In the closed position, the valve body projects from the housing. Furthermore, the valve body includes a sealing portion which comes into contact with a sealing face of the housing between the first bore portion and the second bore portion in the closed position. In a preferred embodiment, the sealing portion includes a sealing ring positioned on the valve body. 
   Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments will be described below with reference to the drawings wherein: 
       FIG. 1  is a longitudinal section view through a first embodiment of an inventive drive; 
       FIG. 2  is a longitudinal section view through the valve according to  FIG. 1 ; 
       FIG. 3  is a front view of the valve according to  FIG. 2 ; 
       FIG. 4  is a perspective view of the valve according to  FIG. 2 ; 
       FIG. 5  is a longitudinal section view of a second embodiment of an inventive drive; and 
       FIG. 6  is a longitudinal section view of a further embodiment of a first and second groove which can be inserted into a drive housing. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     FIG. 1  shows a drive with a drive housing  1  supporting, via deep groove ball bearings  2  and  3 , a first shaft  4  rotatable around a longitudinal axis  13 . The first shaft  4  projects from the drive housing  1 . At a free end of the first shaft, which projects from the drive housing, a receiving bore  5  starts from a first end face  6  of the first shaft  4 . The receiving bore is arranged coaxially relative to the longitudinal axis  13 . As the first shaft  4  extends further, the receiving bore  5  changes into a bore  7  with a reduced diameter. The bore  7  is also arranged coaxially relative to the longitudinal axis  13 . 
   The receiving bore  5  includes first longitudinal teeth  8  in the form of inner teeth. A second shaft  9  is inserted into the receiving bore  5 . The second shaft  9  includes second longitudinal teeth  10  which corresponds to the first longitudinal teeth  8 . The longitudinal teeth  8  and  10  form a splined and a rotationally fast connection between the first shaft  4  and the second shaft  9 . 
   A pin  11  is pressed into the bore  7  of the first shaft  4 . The pin  11  forms part of the first shaft  4 . The pin  11  projects from the bore  7  into the receiving bore  5  and into a central bore  12  of the second shaft  9 . A first joint ring  14  is on the end of the pin  11  which projects from the bore  7  of the first shaft  4 . The first joint ring  14  has a first joint face  15  in the form of a spherical outer face. The first joint ring  14  is positioned inside a second joint ring  16 . The second joint ring  16  has a second joint face  17  in the form of a spherical inner face. The first joint face  15  and the second joint face  17  contact one another at their complementary faces. The second joint ring  16  is positioned in the central bore  12  of the second shaft  9 , so that slight angular deviations can be compensated for between the pin  11  and the second shaft  9 . 
   The drive housing  1  forms an interior  18  which is at least partially filled with a lubricant. The first shaft  4  includes a lubricant channel in the form of a through-bore  19 . The through-bore  19  extends coaxially relative to the longitudinal axis  13  and starts from a second end face  20  which faces away from the first end face  6  and ends in the bore  7  of the first shaft  4 . Furthermore, the pin  11  includes a lubricant channel in the form of a through-bore  22 . The through-bore  22  starts from a first end face  21  of the pin  11  and leads to a second end face  23  of the pin. The first end face  21  is arranged inside the bore  7  of the first shaft  4  so that the pin through-bore  22  communicates with the first shaft through-bore  19 . 
   The pin through-bore  22  has a bore portion  24  with an increased diameter. The bore portion  24  starts from the pin second end face  23  and receive valve  25 . The valve  25  has a housing  26  as well as a valve body  27 . The valve body  27  is axially adjustable along the longitudinal axis  13  in the housing  26  between an illustrated open position and a closed position. The valve body  27  is loaded towards assuming its closed position by a pressure spring  28  which is supported on the pin  11 , on the one hand, and on the valve body  27 , on the other hand. 
   A through-bore  29  is provided in the housing  26 . The through-bore  29  forms a lubricant channel. A sealing face  30  is formed in the through-bore  29 . The sealing face  30 , in the closed position, is contacted by a sealing portion  31  of the valve body  27 . The sealing portion  31  is formed by a sealing ring  32  which is located on the valve body  27 . 
   A switching portion  33 , of the valve body  27 , projects from the through-bore  29  of the housing  26  towards the second shaft  9 . In the open position of the valve body  27  as illustrated, the switching portion  33  axially abuts a cover  34 . The cover  34  is arranged in a bore  35  of the second shaft  9  axially supported against a shoulder  36 . 
   The through-bore  29  of the housing  26  ends in a lubricant chamber  37 . The lubricant chamber  37 , via a radial bore  38  in the second shaft  9 , is connected to the intermediate chamber  39  between the first shaft  4  and the second shaft  9 . The lubricant chamber  37  is partially arranged inside the receiving bore  5 . 
   The lubricant channels, in the form of the through-bores  19 ,  22  and  29 , form a lubricant guiding mechanism which guides lubricant from the interior  18  into the receiving bore  5 . The lubricant flows through the through-bores  19 ,  22  and  29  into the lubricant chamber  37  where it lubricates the joint faces  15 ,  17 . Through the radial bore  38 , the lubricant continues to be guided to the splined teeth where it lubricates the first and second longitudinal teeth  8  and  10 . 
   In order to seal the interior  18 , a sealing ring  41  is provided in the bore  40  of the drive housing  1 . Thus, the first shaft  4  is guided out of the drive housing in a sealed condition. Furthermore, in order to seal the interior  18 , a sealing ring  42  is provided between the first shaft  4  and the second shaft  9 . 
   The valve body  27 , due to the spring force of the pressure spring  28 , is transferred into the closed position when the second shaft  9  is extracted from the receiving bore  5  of the first shaft  4 . Thus, the through-bore  29  is outwardly sealed. Thus, the lubricant cannot escape from the interior  18 . 
     FIGS. 2 ,  3  and  4  show different views of the valve  25  according to  FIG. 1 . The through-bore  29  constitutes a valve bore that includes a first bore portion  43  and a second bore portion  44 . The second bore portion  44  has a smaller diameter than the first bore portion. A guiding portion  45  axially guides the valve body  27  in the first bore portion  43 . The guiding portion  45  is slidingly and radially supported against the inner face of the first bore portion  43 . The cross-section of the guiding portion  45  deviates from the shape of a circle ( FIG. 3 ). Thus through-channels  46  are formed between the guiding portion  45  and the inner wall of the first bore portion  43  and enable lubricant passage. 
   The valve body  27  is guided by the switching portion  33  through the second bore portion  44 . The switching portion  33  has a smaller diameter than the second bore portion  44 . Thus, an annular gap  47  is formed between the switching portion  33  and the inner face of the second bore portion  44 . Thus, lubricant is able to pass through gap  47 . A sealing face  30  is arranged between the first bore portion  43  and the second bore portion  44 . The sealing face  30  has a conical shape. In the closed position as illustrated in  FIG. 2 , the sealing ring  32 , which forms the sealing portion  31  of the valve body  27 , is in sealing contact with the sealing face  30 . The sealing ring  32  is positioned in a circumferential groove  48  of the valve body  27 . When the valve body  27  is transferred from the closed position, as illustrated in  FIG. 2 , into the open position as shown in  FIG. 1 , the sealing ring  32  lifts off the sealing face  30 . Thus, this ensures a through-flow of lubricant. 
     FIG. 5  shows a second embodiment of an inventive drive. A drive housing  101  has deep groove ball bearings  102 ,  103  which rotatably supports a first shaft  104  around a longitudinal axis  113 . The first shaft  104  is guided through an aperture  140  out of the drive housing  101 . The first shaft  104  is sealed by a shaft sealing ring  141 . 
   The first shaft  104  is in the form of a hollow shaft and includes a receiving bore  105  which receives a second shaft  109 . The receiving bore  105  has first longitudinal teeth  108  which engages second longitudinal teeth  110  of the second shaft  109 . This splined connection ensures a rotationally fast connection between the first shaft  104  and the second shaft  109 . The second shaft is also in the form of a hollow shaft which is rotatably arranged on a bearing axle  49 . The bearing axle  49  is guided through a through-bore  50  of the second shaft  109  and is positioned in a bore  51  of the drive housing  101 . Thus, it is possible for the second shaft  109  to be pulled out of the receiving bore  105  of the first shaft  104 , with the second shaft  109  being removed together with the bearing axle  49 . 
   A lubricant channel  52  is provided in the drive housing  101 . The lubricant channel  52  serves as a lubricant guiding mechanism. Lubricant is guided from the interior  118  of the drive housing  101  to the bore  51 . A valve  125  is provided in the region of the bore  51 . The valve  125  corresponds to the valve according to  FIG. 1 , with identical components having been given reference numbers increased by the value of 100. 
   The valve switching portion  133  projects radially inwardly from an inner circumferential face  53  of the bore  51 . Thus, by inserting the bearing axle  49  into the blind bore  51 , the valve body  127  is transferred into the open position. Furthermore, the bearing axle  49  is provided with a groove  54  into which the switching portion  133  projects when the bearing axle  49  is positioned in the bore  51 . Thus, a gap  55  is formed between the bearing axle  49  and the inner circumferential face  53  of the blind bore  51 . The gap  55  ensures that the lubricant is able to flow. The groove  54  extends as far as a lubricant chamber  137  in which the first shaft  104  is supported. The lubricant chamber  137  changes directly into the receiving bore  105 . Thus, when the valve  125  is open, lubricant is ensured to be guided from the interior  118  through the lubricant channel  52 , forming the lubricant guiding mechanism, through the valve  125  along the groove  54  to the receiving bore  105  in order to lubricate the first and second longitudinal teeth  108  and  110 . 
   A shaft sealing ring  58  is provided to ensure that the lubricant chamber  137  is sealed relative to the interior  118 . The shaft sealing ring  56  seals the first shaft  104  relative to the drive housing  101 . Furthermore, a shaft sealing ring  142  is provided between the second shaft  109  and the bearing axle  49  to seal the lubricant chamber  137  towards the outside. 
     FIG. 6  shows a sketch of a further embodiment, illustrating only the first shaft and the second shaft. Any components corresponding to the components of  FIG. 1  have been given reference numbers increased by the value of 200. In this context, reference is made to the description of  FIGS. 1 ,  2 ,  3  and  4 . 
   In this embodiment, the valve  225  is not arranged axially, but radially. In the embodiment according to  FIG. 6 , the second shaft  209  is inserted, from the right, into the receiving bore  105  of the first shaft  104 . A switching cam  57  projects from an end face  58  of the second shaft  209 . The switching cam  57  transfers the valve body  227  from the closed position into the open position upon insertion of the second shaft  209 . A conical end portion  59  is provided on the switching cam to move the valve body  227  between its closed and open position. The switching portion  233  of the valve body  227  is guided along the conical end portion  59  and moves into the open position. Otherwise, the embodiment according to  FIG. 6  corresponds to that of  FIG. 1 . 
   The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.

Technology Category: 2