Abstract:
A vibratory motor having an elongated housing having opposite ends, an electric motor positioned within the housing between the opposite ends, bearings in the opposite ends, a motor shaft extending into the opposite ends and supported by the bearings, eccentric weight chambers in the opposite ends proximate the bearings and between the bearings and the electric motor, explosion and leak-proof seal assemblies located proximate the eccentric weight chambers and between the eccentric weight chambers and the electric motor, each of the seal assemblies including an oil seal facing an adjacent eccentric weight chamber, and a flame path between the oil seal and the electric motor.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   Not Applicable 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not Applicable 
   BACKGROUND OF THE INVENTION 
   The present invention relates to a vibratory motor having an improved seal assembly which is both explosion-proof and prevents bearing lubricating oil from seeping toward its electric motor. 
   In the past vibratory motors of the type shown in U.S. Pat. No. 6,580,189 included an explosion-proof seal between the electric motor and the lubricated bearings which supported the motor shaft at the ends of an elongated motor housing. However, the prior seal did not prevent bearing lubricating oil from seeping toward the electric motor of the vibratory motor. 
   BRIEF SUMMARY OF THE INVENTION 
   It is one object of the present invention to provide an improved seal assembly between the electric motor and the bearings at the end of an elongated motor housing, with the improved seal assembly being both oil leak-proof and explosion-proof. 
   A related object of the present invention is to provide an improved vibratory motor as described in the immediately preceding paragraph wherein the oil seal does not extend into an adjacent chamber which houses the eccentric weights mounted on the shaft so that there is room in the eccentric weight chamber for a large number of weights. 
   A further related object of the present invention is to configure the explosion-proof seal with a boss which extends toward the electric motor and therefore does not extend into the eccentric weight chamber. Other objects and attendant advantages of the present invention will readily be perceived hereafter. 
   The present invention relates to an improvement in a vibratory motor having an elongated housing having opposite ends, an electric motor positioned within said housing between said opposite ends, bearings in said opposite ends, a motor shaft extending into said opposite ends and supported by said bearings, eccentric weight chambers in said opposite ends proximate said bearings and between said bearings and said electric motor, the improvement comprising explosion and leak-proof seal assemblies located proximate said eccentric weight chambers and between said eccentric weight chambers and said electric motor, each of said seal assemblies including an oil seal facing an adjacent eccentric weight chamber, and a flame path between said oil seal and said electric motor. 
   The various aspects of the present invention will be more fully understood when the following portions of the specification are read in conjunction with the accompanying drawings: 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       FIG. 1  is an end elevational view of the improved vibratory motor of the present invention; 
       FIG. 2  is a cross sectional view taken substantially along line  2 — 2  of  FIG. 1 ; 
       FIG. 3  is an enlarged view of the left end of  FIG. 2 ; 
       FIG. 4  is a cross sectional view taken substantially along line  4 — 4  of FIG.  3  and showing the shape of the eccentric weights; 
       FIG. 5  is a fragmentary cross sectional view taken substantially along line  5 — 5  of FIG.  3  and showing the funnel which receives lubricating oil; 
       FIG. 6  is a fragmentary cross sectional view taken substantially along line  6 — 6  of FIG.  3  and showing an oil conduit; 
       FIG. 7  is a perspective view of the spacer which is used to space the weights from the portion of the motor housing the bearings; 
       FIG. 8  is a perspective view of the explosion-proof and leak-proof seal assembly; and 
       FIG. 9  is a fragmentary enlarged cross sectional view of the joints between the seal assembly and the motor shaft and the motor housing. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Summarizing briefly in advance, the improved vibratory motor  10  is an improvement of the vibratory motor having a self-contained continuous bearing lubrication system of U.S. Pat. No. 6,580,189 in that it adds a sealing assembly thereto which both prevents lubricating oil from leaking toward the electric motor and prevents any flame emanating from the electric motor from reaching the lubricating oil for the bearing. 
   The improved vibratory motor  10  includes an elongated housing  11  having an electric motor  12  mounted substantially at a midpoint thereof. The motor  12  includes a stator  13  and a rotor  14  which is keyed to shaft  15 . The shaft is supported at its opposite end portions by bearings  17  which are continuously lubricated in accordance with the teaching of U.S. Pat. No. 6,580,189. Mounted on shaft  15  is a plurality of eccentric weights  19  having the configuration of FIG.  4 . Each weight includes a pin  20  which is received in a groove  21  of shaft  15  and the weights are clamped onto shaft  15  by tightening screw  22  which bridges the slot  23  of each weight  19 . 
   At this point it is to be noted that the bearing and weight constructions at each end portion of the vibratory motor are mirror images. Therefore, the structure only at the left end portion of  FIG. 2  will be described, and it will be understood that the undescribed structure at the right end of  FIG. 2  is the mirror image thereof. 
   The continuous bearing lubrication structure will be briefly described solely because of the fact that an oil seal is provided as part of the seal assembly to prevent oil from seeping toward the electric motor  12 . The basic portions of this lubrication system is completely described in U.S. Pat. No. 6,580,189, which is incorporated herein by reference. However, there may be minor structural variations between the present continuous lubrication structure and that of the patent. 
   Briefly, bearing  17  is a roller type of bearing which has an inner race, and outer race, and a plurality of roller bearings therebetween. Bearing  17  is mounted into motor housing portion  23  in the following manner. A ring  24  is shrunk-fitted into housing portion  23 . The outer race of bearing  17  is press-fitted into bearing bracket  25  and the inner race of bearing  17  is press-fitted onto shaft  15 . The bearing bracket  25  is then suitably bolted to ring  24  to complete the bearing assembly. 
   The bearing  17  is lubricated in the following manner. A pool of lubricating oil is contained in chamber  27 . As the motor  10  operates, the vibrations will cause the oil in chamber  27  to splash violently and enter the open top  30  of funnel  31  and thereafter pass through tube  32  into the hollow inside  33  of shaft  15 . The oil is thereafter conducted to the roller bearing  17  in the following manner. The oil travels outwardly through four conduits  34  in shaft  15  which are spaced  900  apart and thereafter enters four grooves  35  in shaft  15 . The oil then passes along the outside of the inner race of bearing  17  and through the entire bearing to lubricate it. This is fully described in U.S. Pat. No. 6,580,189. 
   A spacer ring  37  ( FIGS. 3 and 7 ) is shrunk-fitted onto shaft  15  to rotate therewith. Spacer  37  spaces weights  19  away from housing portion  23 . A plurality of indented portions  39  and the smaller diameter portion  40  of spacer  39  receive oil, and there is a clearance  41  between the outer surface  42  of spacer  37  and the adjacent portion of housing  23  which constitutes a passage through which oil enters chamber  43 . The oil then passes from chamber  43  through conduit  44  into chamber  45 . As shaft  15  rotates, the oil will be thrown upwardly by weights  19  through opening  47  ( FIGS. 3 and 5 ) above shelf  49  and will enter chamber  27  from which the lubrication cycle is repeated. It is to be noted that chamber  27  is in communication with its mirror-image counterpart chamber  27 ′ through conduit  50  in housing  11 , thereby equalizing the level of lubricating oil in both of these chambers. As noted above, the basic structure of the continuous lubrication system is set forth in U.S. Pat. No. 6,580,189. 
   In accordance with the present invention, an explosion-proof and leak-proof seal assembly  51  is provided to prevent any flame emanating from motor  12  from entering chamber  43  and for preventing any oil from chamber  43  from passing toward motor  12 . The seal assembly  51  includes an outer rim consisting of rim portion  52  and rim portion  57 . Rim portion  57  is shrunk-fitted into housing  11  and rim portion  52  is bolted to housing  11  by a plurality of bolts  53  which pass through holes  54 . This double fastening is desired because of the violent vibration to which motor  10  is subjected. Rim portion  52  has a face  56  which faces chamber  43 . An O-ring  55  provides a seal between cylindrical rim portion  57  and the adjacent portion of housing  11 . A boss or protuberance  59  extends outwardly beyond shrink-fitted portion  57  toward motor  12 . The end of boss  59  is configured with a counterbore  60  which receives stepped portion  61  of shaft  15  to provide a labyrinth. The overlap between the stepped portion  61  of the shaft and the counterbore  60  is 0.25 inches long and the diametrical clearance is 0.0275 inches and there is an open space at  66  which is 0.125 inches long and 0.3040 inches radially. A flame path  62 , which is essentially a clearance between shaft  15  and boss  59  extends lengthwise for a prescribed distance so that any flame which may enter this clearance from motor  12  will be dissipated before it reaches the end  63  of seal assembly  51 . By way of example, in the present instance, the length of the flame path is 2.3750 inches and the diameter of the shaft is 2.6340 inches and the clearance with the shaft  15  is 0.0275 inches. It will be appreciated that the flame path  62  has to be dimensioned to meet safety requirements. A slightly different construction is at the right side of the shaft where a labyrinth ring  70  is shrunk-fitted onto the shaft  15  to provide a labyrinth with the right seal assembly having the same dimensions as the above-described labyrinth. Also, the flame path has the same dimensions as described above relative to flame path  62 . 
   The seal assembly  51  also carries an oil seal  64  at its end facing chamber  43 . This seal is pressed into the recess at end  63  and an O-ring  65  is placed therebetween. The seal  64  is of the type known under the trademark INPRO/SEAL which is manufactured by the Inpro/Seal Company of Rock Island, Ill. The face  67  of the seal does not extend any distance beyond face  56  of the seal assembly into chamber  43 , thereby leaving room within chamber  43  in the event that an additional eccentric weight  19  is to be mounted on shaft  15 . In this event, the groove  21  might have to be extended. Also, the oil seal should not extend any substantial distance into chamber  43  which would prevent the adding of eccentric weights in chamber  43 . It is to be understood that the foregoing terminology is intended to include the condition wherein the face of the oil seal does not extend into the adjacent eccentric weight chamber at all. 
   While a preferred embodiment of the present invention has been disclosed, it will be appreciated that it is not limited thereto but may be otherwise embodied within the scope of the following claims.