Abstract:
A removable particle collector for an apparatus which separates metal particles from lubricating oil. A valve assembly has a bore that provides a passage into the reservoir from outside. A valve element is normally biased against a valve seat to close the bore. A plug has a stem which when inserted into the valve assembly bore forces the valve element away from the valve seat. A portion of the stem is magnetized to attract ferromagnetic particles in the reservoir. A plurality of balls rotatably project from a surface on either the valve assembly or the plug and are received in a plurality of locking grooves in the other of the valve assembly and the plug to secure those components together. The balls are lubricated by fluid from the reservoir and can rotate to reduce wear which could loosen the components.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Not Applicable 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to apparatus for separating metal particles from lubricating oil in which the particles are suspended, and to devices for collecting and measuring the quantity of separated metal particles in such apparatus. More particularly the present invention is related to quick connect and disconnect mechanisms to attach the collecting and measuring device to the particle separating apparatus in a removable manner. 
   2. Description of the Related Art 
   Mechanical power transmission equipment is subject to wear due to friction caused by the contact of moving parts under pressure at relatively high speeds. This results in abrasive wearing of component surfaces with the resulting release of small particles. Such “wear particles” are generally less then twenty microns in size and become suspended in the oil used to lubricate the moving components. 
   It is desirable to remove such particles from suspension in the lubricating oil to prevent them from being re-circulated with the oil and further contributing to the abrasion of the moving parts. U.S. Pat. No. 4,199,443 discloses an apparatus for removing the particles suspended in the lubricating oil. In this type of mechanism, the oil tangentially enters a cylindrical housing thereby producing rotary downward motion of the oil which creates a vortex in the housing. That vortex flow causes the heavier particles to be transported by centrifugal force against an outer wall and to the bottom of the housing where the particles accumulate. A filter is provided to remove particles which would otherwise remain suspended in the oil flowing through the apparatus. 
   A collector is mounted at the bottom of the chamber to gather the accumulated particles. A common type of collector incorporates a permanent magnet to attract ferromagnetic particles from moving machine parts that are made of steel. Periodically, a mechanic removes the collector to inspect the accumulation of particles thereon and determine an amount of wear of the machine components. Another type of collector includes a sensor with electrical contacts adjacent the permanent magnet and the accumulation of metal particles forms an electrical bridge between the contacts. The amount of metal particle accumulation can be determined by measuring the electrical conductivity between those contacts. 
   All types of these collectors must be periodically detached from the separator housing in order to remove the accumulated particles. As a consequence, a quick connect and disconnect mechanism has been employed to attach the collector to the housing of the particle separator. A “bayonet” connector commonly is used in which two or more cylindrical pins are fixed to either the collector device or a mating fitting secured to the housing. The other component included a like number of grooves, often having a J or L shape, with each groove receiving one of the pins. 
   The cylindrical pins tended to wear due to vibration of the machinery on which the particle removal apparatus was located. The vibration applied forces in orthogonal directions on the pin. The vibration induced wear loosened the fit between the particle collector and the separator housing. Such loosening of the collector enabled the lubricating oil to leak from the apparatus. If such pin wear was allowed to continue undetected, the collector occasionally detached from the separator housing. 
   As a consequence, it is desirable to provide an alternative quick connect and disconnect mechanism for holding such collectors onto particle separators. 
   SUMMARY OF THE INVENTION 
   A collector is provided to gather metal particles in a reservoir of an apparatus which separates the particles from lubricating oil. The collector includes a valve assembly with a bore that forms a passage between inside and outside of the reservoir. The valve assembly has a cylindrical first surface outside the reservoir. A plug has a stem that is removably received within the bore of the valve assembly and has a body with a cylindrical second surface which mates with the first surface. 
   A plurality of balls rotatably project from one of the first surface and second surface. The other of the first surface and second surface has a plurality of locking grooves, in which the plurality of balls are releasably received to secure the valve assembly and plug together. 
   The design of the preferred embodiment of the collector is such that lubricating oil from the reservoir is able to flow to the balls, This lubrication of the balls and the balls ability to rotate while securing the collector components together reduces wear which tends to loosen the connection between those components. 
   Another preferred aspect of the present collector is magnetizing a portion of the plug stem to attract ferromagnetic particles in the reservoir. Electrodes may be provided on the magnetized portion of the plug stem to electrically sense the accumulation of the ferromagnetic particles. 
   Another embodiment of the present invention provides a collector for non-ferromagnetic particles in the reservoir. This collector has a screen through which the lubricating oil flows to thereby trap the particles. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a cross-sectional view through a valve assembly of a collector that incorporates a connector according to the present invention; 
       FIG. 2  is an isometric view of the valve assembly; 
       FIG. 3  is an isometric view of an alternative connector arrangement on the valve assembly; 
       FIG. 4  is a cross-sectional view of the collector with a plug attached to the valve assembly; 
       FIG. 5  is an isometric view of the collector plug; 
       FIG. 6  is an fragmented cross-sectional view which shows a ball securing the plug to the valve assembly; 
       FIG. 7  is a cross-sectional view along line  7 — 7  in  FIG. 5 ; 
       FIGS. 8–10  are isometric views of three alternative types of connector plugs; 
       FIG. 11  is an isometric view of an alternative design of a valve assembly incorporating the present invention; 
       FIGS. 12–15  illustrate four types of collector plugs that can be utilized with the alternative valve assembly in  FIG. 11 ; 
       FIG. 16  is a cross-sectional view through a valve assembly of a collector for non-ferromagnetic particles; 
       FIG. 17  is an isometric view of a plug that mates with the valve assembly in  FIG. 16 ; and 
       FIG. 18  is a cross-sectional view of the plug inserted into the valve assembly. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   With initial reference to  FIG. 1 , a particle collector  10  has a valve assembly  12  which is threaded into an aperture  14  in a reservoir  16  or other section of a machine lubrication system which contains lubricating oil  18 . The valve assembly  12  has a tubular housing  20  with a hexagonal flange  22  that abuts the outer surface of the reservoir  16 . The tubular housing  20  has a threaded section  15  which engages threads in the reservoir aperture  14  to the hold the valve assembly  12  in place. An annular seal  24  blocks fluid from passing through the aperture  14 . 
   With additional reference to  FIG. 2 , an interior section  26  of the housing  20  which extends into the lubricating oil  18  has three rectangular apertures  28  in the curved outer wall, thereby providing paths through which the lubricating oil enters the longitudinal bore  30  of in the tubular housing  20 . A valve element  32  is slidably received within the interior section  26  and is biased by a spring  34  against a valve seat  36  formed in the bore  30 . Engagement of the valve assembly  32  with the valve seat  36  closes the bore  30  preventing the lubricating oil from flowing between the interior section  26  and an exterior section  38  of the valve assembly housing  20 . The interior end  40  of the tubular housing  20  is closed by a plate  42  which is secured across the bore opening and which is engaged by one end of the spring  34 . 
   As seen in  FIG. 2 , the exterior section  38  of the tubular housing  20  has three generally J-shaped locking grooves  44  spaced equidistantly around the outer circumferential surface. The grooves  44  are slanted about that surface thus resembling a “check mark”. Alternatively, as shown in  FIG. 3 , the locking grooves  44  may more closely resemble the letter J with an elongated section  69  extending parallel to the longitudinal axis of the valve assembly  12  from the end of the plug. A notch  70  is located at the inner end of the elongated section  69  and extends to one side thereof. As will be described, each of these locking grooves  44  receives a ball located on a mating plug of the quick connector  10  in order to secure the plug on the valve assembly  12 . 
   Referring to  FIGS. 4 and 5 , a plug  50  is inserted through the exterior section  38  of the valve assembly  12 . The plug  50  has a cylindrical stem  52  which extends into the bore  30  of the tubular housing  20 . A nose  54  projects from the interior end of the stem  52  abutting the valve element  32  of the valve assembly  12 . When the plug  50  is fully inserted into the valve assembly  12 , the nose  54  pushes the valve element  36  away from the valve seat  36  and against the force of spring  34 . This opens the bore  30  of the tubular housing  20 . 
   The exterior end of the plug stem  52  has an integral body in the form of a cap  56  extending there around and encircling the exterior section  38  of the valve assembly  12 . An annular retainer  58  is press fitted within the interior of the cap  56 . A first sealing ring  60  provides a water tight interface between the retainer  58  and the interior of the cap  56 . The interior diameter of the annular retainer  58  engages a second sealing ring  62  located in a groove around the exterior section  38  of the valve assembly  12  to provide a fluid seal there between. With additional reference to  FIG. 6 , the retainer  58  has three notches  64  spaced radially at equal increments around its interior diameter. A ball  66  is captivated in each of the notches  64  in the retainer  58 . Specifically, the retainer  58  has notch lips  67  and  68  that extend around the ball to prevent it from traveling toward the stem  52  when the plug  50  is removed from the valve assembly  12 . 
   When the plug  50  is inserted into the valve assembly  12 , it is aligned rotationally so that each ball  66  enters an elongated section  69  of one of the locking grooves  44  in the exterior section  38  of the valve assembly. As the plug  50  is pushed farther into the valve assembly  12 , it is rotated so that each of the balls  66  follows elongated section  69  of the locking groove  44 . When the balls  66  reach the interior end of the locking grooves  44 , the plug  50  can not be rotated further about the valve assembly  12 . In this position, the installer releases the plug  50  which results in the force of spring  34  pushing the valve element  32  and the plug nose  54  slightly outward so that the balls  44  enter the notch  70  at the inner end of each locking groove  44 . The balls  66  are captivated in the notches  70 , thereby securing the plug  50  on the valve assembly  12 . 
   The force which the spring  34  exerts on the plug  50  minimizes the effects of vibration along the axis of the plug. The spring force also effects the vector load on the balls  66  which wedges the balls between the valve housing  20  and the plug  50  to fix the plug radially within the valve assembly. Referring to  FIG. 6 , the spring force is transferred along a line between point  71  where the ball  66  contacts the retainer  58  and point  72  at which the ball  66  contacts the locking groove  44  in the valve assembly  12 . That line for each of the balls  66  intersects the longitudinal axis  45  of the plug  50  thereby centering the plug in the valve assembly bore  30  thereby minimizing the vibrational effects acting on the plug. The contours of the notches  64  and the locking grooves  44  are such that each ball  66  contacts those surfaces in only two places, which minimizes vibration in the X and Y directions. 
   With reference to  FIGS. 5 and 7 , an annular groove  74  extends around the stem  52  of the plug  50 . The bottom of this groove  74  has flat portions  75  so that the cross-section of the stem  52  at this point has the shape of a triangle with rounded apexes, as seen specifically in  FIG. 7 . A resilient, annular spacer  76  extends around the plug stem  52  within the groove  74  to dampen vibration of the stem within the bore  30  of the valve assembly  12  (see  FIG. 3 ). Note that the triangular shape of the plug stem inside the groove  74  creates gaps  77  between the spacer  76  and the valve assembly bore  30  at three points around the plug stem  52 . These gaps  77  allow lubricating oil that enters through apertures  28  to flow between the plug stem  52  and the valve assembly  12  into the cap  56  of the plug  50  and around the balls  66 . This oil flow lubricates the balls, thereby reducing their wear that would otherwise result from vibrational forces. The second sealing ring  62 , around the exterior section  38  of the valve assembly  12 , prevents this lubricating oil from leaking through the particle collector  10 . 
     FIG. 5  illustrates a basic version of the plug in which the nose  54  and adjacent section of the valve stem  52  are magnetized to form a permanent magnet. These magnetized portions of the plug  50  attract ferromagnetic particles suspended in the fluid  18  in the reservoir  16  which then collect on those portions. With this type of particle collector, a mechanic periodically removes the plug  50  to inspect the quantity of particles which have accumulated on the permanent magnet section. These particles may be removed from the plug before it is replaced on the valve assembly  12 . Note with respect to  FIG. 1  that when the plug  50  is removed from the valve assembly  12 , the spring  34  forces the valve element  32  against the seat  36 , thereby preventing escape of lubricating oil  18  from the reservoir  16 . 
     FIG. 8  illustrates an alternative collector plug  80  which incorporates a particle sensor. In this component, the permanent magnetic nose  54  extends from a shoulder surface  82  of the plug stem  52 . A pair of annular electrodes  83  and  84  are formed on the shoulder  82  extending around the nose  54 . The electrodes  83  and  84  are connected to wires which run through the interior of the plug stem  52  to an electrical connector  85  at the exterior end of the plug. A cable that mates with the electrical connector  85  connects the electrodes  83  and  84  to equipment which senses current flow between the electrodes. As metal particles accumulate on the end of the plug stem  52 , an electrical path is formed between electrodes  83  and  84 . The conductivity of that electrical path increases with the accumulation of metal particles, so that the amount of particle accumulation can be sensed by measuring that conductivity without removing the plug  87  from the valve assembly  12 . 
     FIG. 9  illustrates another collector plug  86  which has an electrical particle sensor around the magnetized nose  54 . This collector plug  86  includes two electrodes  87  and  88  extending around a circumferential surface at the inner end of the plug stem  52 . The electrodes  87  and  88  are connected to wires which run through the interior of the plug stem  52  to an electrical connector  85  at the outer end of the plug  86 . As with the embodiment in  FIG. 7 , the accumulation of metal particles at the inner end of the plug stem, due to its magnetization, creates an electrical path between the two electrodes  87  and  88 . 
     FIG. 10  illustrates a further type of plug  90  which attaches a hose or tube  92  to the reservoir  16 . Specifically, plug  90  has a tubular housing  94  extending through the cap  95  with the tube  92  connected to the exterior end of the tubular housing. An end ring  96  is spaced from the interior end of the tubular housing  94  by a pair of posts  97  (only one of which is visible in the drawings). When the plug  90  is inserted through the valve assembly  12  in a manner similar to plug  50  in  FIG. 3 , the end ring  96  pushes the valve element  32  inward away from the valve seat  36 . This enables fluid  18  from the reservoir  16  to enter the space between the end ring  96  and the tubular housing  94  and flow through the bore in the stem  94  into the tube  92 . This plug and tube assembly shown in  FIG. 10  can be utilized to introduce fluid into the reservoir  16  or remove fluid there from. It will be appreciated that a valve mechanism can be attached to the other end of the tube  92  in order to control the flow of oil through the tube. 
   Referring to  FIG. 11 , an alternative version of the valve assembly  100  has a structure similar to that of the valve assembly  12  shown in  FIGS. 1–3 . However, this alternative valve element  100  does not have locking grooves on the outer surface of the exterior section  102 . Instead, three balls  104  are held by a retainer  106  inside the bore of the valve assembly  100 . The retainer  106  is similar to retainer  58  described with respect to the previous embodiment and captivates the balls  104  within the valve assembly  100 . The balls engage grooves in the plug that mates with the valve assembly  100  thereby securing those components together. 
   Specifically,  FIGS. 12 ,  13 ,  14  and  15  illustrate plugs  110 ,  112 ,  114  and  116  which correspond to the plugs in  FIGS. 5 ,  8 ,  9  and  10  respectively. Each of these plugs  110 – 116  has a cylindrical body  118  with an exterior surface in which three locking grooves  120  are located to receive the balls  104  of the valve assembly  100 . The locking grooves  120  have a J-shape which can either be aligned with the axis of the plug or slanted with respect thereto to have a check mark appearance. Each of these alternative plugs  110 – 116  has an annular spacer  122  which allows lubricating oil to flow from the reservoir along the plug stem to the balls  104  in grooves  120 . This lubrication not only reduces wear of the abutting Surfaces, it also enables the balls to rotate in place due to the vibration thereby distributing what wear does occur over the entire surface of the ball. Therefore, unlike the fixed pins used in previous connectors, surface contact and wear are not limited to one section of each ball. An additional exterior seal  124  is provided around the plug&#39;s cylindrical body  118  to engage the valve assembly  100  and prevent that oil from leaking from the connector. 
   With reference to  FIG. 16 , a third version of a particle collector  200  is provided for gathering non-ferromagnetic particles. With this version, the valve assembly  202  is threaded into an aperture in the particle separator  204  and extends into a tubular member  206 . The lubricating oil flowing in the particle separator  204  enters an internal cavity  208  in the tubular member  206  and exits into the particle separator reservoir  219  through the second apertures  217  in the tubular member. 
   The valve assembly  202  has an interior tubular section  212  the end of which projects into the particle separator cavity  208  and has a plurality of apertures first spaced axially around the tubular section  212 . The first apertures  214  form passages between the internal cavity  208  in the tubular member  206  and the longitudinal bore  216  of the valve assembly  202 . A valve element  218  is slidably located within the longitudinal bore  216  and is biased by a spring  220  against a valve seat  222 . When the valve element  218  engages the valve seat  222 , the interior portion of the longitudinal bore  216  is closed off from the exterior portion in the same manner as with the previously described valve assemblies. 
   The exterior section  223  of the valve assembly  202  has a tubular construction which is identical to that of the exterior section  38  of the valve assembly  12  shown in  FIGS. 1 and 2 . Specifically, there are three locking grooves  225  spaced at equal increments axially around the exterior surface of the valve assembly&#39;s outer end. 
   When a plug is not inserted into the valve assembly  202  as seen in  FIG. 16 , lubricating oil flowing in the particle separator  204  enters an internal cavity  208  in the tubular member  206  from which the oil continues to flow into the longitudinal bore  216  of the valve assembly  202  entering through first apertures  214  The oil exits the longitudinal bore  216  through a plurality of second apertures  217  in the valve assembly and apertures  210  in the tubular member  206 , thereby flowing into the particle separator reservoir  219 . 
   With reference to  FIG. 17 , a collector plug  230  has a body  238  from which a stem portion  232  projects. The interior end of the stem portion  232  has a cylindrical screen  234  fabricated of a non-electrically conducted material, such as a rigid plastic mesh. A metal ring  236  extends around the open end of the cylindrical screen  234  to form a first sensing electrode. A second sensing electrode  240  extends around the end of the stem  232  at the junction with the screen  234 . Wires lead from the ring  236  and electrode  240  to a connector  242  at the exterior end of the plug  230 .  100471  With reference to  FIG. 18 , the plug  230  has three balls  244  held within notches of a retainer  246  of the body  238 . When the plug  230  is inserted into the valve assembly  202 , it is aligned rotationally so that each ball  244  enters one of the locking grooves  222  in the valve assembly. The plug  230  is rotated as it is pushed farther onto the valve assembly, so that each ball  244  follows the locking groove  225 . When the balls reach the interior ends of locking grooves, and the plug  230  cannot be rotated further about the valve assembly  202 , the plug is released. At that time, the force exerted oil the plug  230  by valve assembly spring  220  forces the balls into the notches at the end of the groove, thereby securing the plug onto the valve assembly in the same manner as described herein in respect of the plugs. 
   As the stem  232  of plug  230  is inserted into the bore  216  of the valve assembly  202 , the ring  236  pushes the valve element  218  inward against the force of the spring  220 . When the plug  230  is fully inserted into the valve assembly, as shown in  FIG. 18 , transverse apertures  250  the valve element  218  are aligned with the first apertures  214  in the valve assembly. This alignment provides a path between the particle separator cavity  208  and the interior of the valve element  218  which opens into center of the ring  236  and cylindrical screen  252  of the plug. This allows lubricating oil to flow into the interior of region  252  of the plug screen  234 . The lubricating oil continues to flow laterally through the screen  234 , second apertures  217  in the valve assembly  202 , and apertures  210  in the tubular portion  206  of the particle separator. Therefore, the lubricating oil is circulated through the plug screen  234  before entering the reservoir  219  and the screen traps particles suspended in the lubricating oil. The accumulation of the metal particles on the screen  234  effects the conductivity between the end ring  236  and the electrode ring  240  on the plug  230 . As described previously, that conductivity and thus the accumulation of non-ferromagnetic metal particles can be sensed by external circuitry. 
   In an alternative variation of the particle collector  200  in  FIGS. 16–17  the locking grooves can be formed in the plug body  238  and the balls mounted in the exterior section  223  of the valve assembly  202 . Both variations of the ball and groove locking mechanism for the valve assembly  202  and collector plug  230  have the same advantages over prior connecting mechanisms as described with respect to the other versions of the present invention. 
   The foregoing description was primarily directed to a preferred embodiment of the invention. Although some attention was given to various alternatives within the scope of the invention, it is anticipated that one skilled in the art will likely realize additional alternatives that are now apparent from disclosure of embodiments of the invention. Accordingly, the scope of the invention should be determined from the following claims and not limited by the above disclosure.