Abstract:
A drive axle assembly is provided which includes a gear housing and differential gear set. An insert is provided which is disposed in a lubricant reservoir of the gear housing. The insert directs lubricant away from the reservoir upon rotation of the differential gear housing.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The field of the present invention is drive axle assemblies and more particularly, drive axle assemblies commonly used in trucks. 
     2. Discussion of Related Art 
     Many trucks have a drive axle assembly which includes a gear housing provided by an integral axle housing. The gear housing has a front opening to allow for connection of its input shaft with an exterior yoke or flange which is in turn connected with a drive shaft of the vehicle. The input shaft powers a pinion gear which is meshed with a ring gear. The ring gear is connected with a differential carrier. The carrier is connected with a spider having spider gears rotatively mounted thereon. The spider gears are meshed with opposing side gears. The side gears are connected with two side journals or half shafts. The half shafts extend laterally outward from the gear housing to drive the drive wheels of the vehicle. The gear housing is either integral with or fixably connected with an axle housing. The axle housing encloses the half shafts. 
     The gear housing has an opening to allow for the insertion of the various components of the differential gear set. An enclosure member is provided to close the opening. The enclosure member and gear housing provides a lubricant reservoir, which is commonly filled with oil. The function of the oil is to lubricate the primary gearing, differential gear set and associated bearings. Oil is allowed to flow through the axle housings and also to lubricate the half shaft bearings which are most adjacent to the connected wheels. The rotation of the ring gear causes the lubricant to be circulated within the gear housing. 
     Various contaminants can be present within the lubricant. Foundry sand may be present due to insufficient cleaning of the housing before the axle assembly operation. Working of the various gears within the gear housing can cause particles of metal to be produced within the lubricant. Such particles can cause undesirable wear upon the gear train and inhibit the proper flow of lubricant throughout the axle assembly. 
     Another consideration in the design of drive axle assemblies is to reduce the temperature of the lubricant to maximize the lubricant&#39;s effective life. The churning of the lubricant within the reservoir by the ring gear causes the lubricant temperature to rise. To cool the lubricant it is desirable that as much lubricant as possible passes out of the gear housing and into the arms of the axle housings or in the suspension within the gear housing atmosphere. Movement of lubricant into the axle housing arms is also desirable to ensure proper lubrication for the inboard and outboard bearings that support the half shafts. 
     To maximize fuel efficiency of the vehicle it is desirable to reduce vehicular weight. Therefore it is desirable to provide a drive axle assembly housing wherein the mass of lubricant within the axle housing can be held to a minimum and reduce component churning efficiency loss that will reduce energy consumption. 
     SUMMARY OF THE INVENTION 
     To make manifest the aforementioned desires, a revelation of the present invention is brought forth. In a preferred embodiment the present invention provides an insert which is placed within the gear housing to displace volume of the lubricant reservoir formed therein. The insert can be fabricated to be hollow or a solid polymeric body, which provides two significant advantages. The first advantage is that a significant amount of lubricant is displaced from its reservoir within the gear housing and is pushed towards the side arms of the axle housing to better lubricate the inboard and outboard bearings of the half shafts. Additionally the insert can have pockets formed therein. The pockets form enclosed pools which are accessible from the top. Placed within the pockets of the insert are magnets. Ferro metallic contaminants within the lubricating oil are held within the pockets by the magnets placed within the pockets. 
     It is an advantage of the present invention to provide a drive axle assembly having an insert which displaces liquid within the lubricant reservoir of the gear housing while providing pockets having magnets located therein for the entrapment of ferro metallic contaminants within the lubrication oil. 
     The above noted and other advantages of the present invention will be more apparent to those skilled in the art as the present invention is further revealed in the accompanying drawings and detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partially sectioned top view of a preferred embodiment axle housing according to the present invention. 
         FIG. 2  is a partially sectioned front elevational view of the axle housing assembly shown in  FIG. 1  illustrating placement of the inventive insert therein. 
         FIG. 3  is a side elevational view of the axle assembly shown in  FIGS. 1 and 2 . 
         FIG. 4  is a perspective view of the insert shown in  FIGS. 1 through 3 . 
         FIG. 5  is a sectional view illustrating the connection between the insert and gear housing. 
         FIG. 6  is a view similar to  FIG. 5  of an alternate preferred embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to  FIGS. 1-5  the drive axle assembly  7  of the current invention has a gear housing  10 . The gear housing  10  is integrally formed by an axle housing  12 . The axle housing  12  has a front opening  14 . The front opening  14  is enclosed by an enclosure member provided by a carrier  15 . The axle housing  12  has a rear opening which is covered by an enclosure member provided by an axle housing cover  16 . The axle housing  12  has two integrally formed side arms  18 . The gear housing  10  along with its connected enclosure members provided by carrier  15  and axle housing cover  16  provides a lubricant reservoir which will be filled with a lubricating oil. 
     Rotatably mounted by front and rear bearings (not shown) within the carrier  15  is an input shaft  20 . The input shaft  20  is connected with a yoke or flange  22  to receive torsional force from a drive shaft (not shown) of the vehicle. A rear end of the input shaft  20  is connected with a pinion gear  26 . Pinion gear  26  is meshed with a ring gear  28 . The ring gear  28  mounts a differential carrier  30 . The carrier  30  mounts a differential spider  32  which has a plurality of spider gears  34  mounted thereon. The spider gears engage with a side gear  36 . The side gear  36  is connected with a half shaft or side journal  38 . Another side gear  40  which is connected with a side journal  42  also meshes with the spider gears  34  completing the differential gearing of the drive axle assembly  7 . 
     The side journal  38  is rotatably mounted within the axle housing by sleeve bearing (not shown). The sleeve bearing is fitted within an extension  37  of the differential carrier  30 . The extension  37  is rotatively supported by a tapered roller bearing  46 . In similar fashion the ring gear  28  has an extension  39 . The ring gear extension  39  is mounted within the axle housing by a bearing  48 . A sleeve bearing (not shown) supports the side journal  42  within the extension  39 . The outboard ends of the side journals  38 ,  42  are supported by tapered roller bearings (not shown) fitted within the side arms  18  of the axle housing  12 . 
     It is apparent to those skilled in the art that many drive axle assemblies have the carrier  15  integrally formed with the axle housing, thus providing a fastener attached axle housing cover. Alternatively, an axle housing cover may be integrally formed with the axle housing with a fastener attached carrier. Both arrangements are within the scope of the present invention. 
     As mentioned previously the gear housing  10 , integral with the axle housing along with its connected enclosure members forms a lubricant reservoir. Disposed within the lubricant reservoir is an insert  70 . The insert  70  (best shown in  FIG. 4 ) can be fabricated from a hollow or solid piece of material. Preferable materials are a lightweight polymeric material such as closed-cell foam, ABS, PVC plastic or other suitable alternatives. The insert  70  has a ring gear pocket  72 , which provides clearance for the ring gear  28  to rotate therethrough. The insert  70  additionally has contaminant pockets  74 ,  76 . The contaminant pockets  74 ,  76  form an enclosed pool. The enclosed pool is accessible from the top. Placed within the bottom of the pockets  74 ,  76  are magnets  82 ,  84 . The pockets  74 ,  76  are positioned underneath the respective bearings  46 ,  48 . Ferro metallic contaminants from the bearings  46  or  48  or from other sources will be captured within the pockets  74 ,  76  by the magnets  82 ,  84 . 
     The insert  70  also has deflector surfaces  90 ,  94  to direct the oil to interact with the ring gear outwardly towards the side arms  18  to lubricate the bearings  46 ,  48  and the outboard bearings. 
     Referring to  FIG. 5 , the insert  70  is connected with the gear housing  10  via, a fastener  96  that passes through a flange  98  of the carrier  15 . The fastener  96  also passes through a ring  100  which abuts a flange  102  of the gear housing. The fastener  96  then threadably enters a bore  104  provided in a thickened portion  106  of the insert  70 . The insert  70  fills a portion of the volume of the lubricant reservoir therefore reducing the total amount of lubricant required. By being hollow, an even greater weight savings is achieved by the insert&#39;s placement within the drive axle assembly. A slight clearance underneath the insert  70  provides a passage  112  that allows magnetic contaminants to be entrapped underneath the insert  70 . 
     Referring additionally to  FIG. 6  with similar parts given like reference numerals, an insert  71  is connected with the gear housing by an adhesive patch  108 . Passage  120  is provided between underlying ribs  122  of the insert  71 . This allows ferro magnetic contaminants to be entrapped underneath the insert  71  by their attraction to the magnet  82 . If desired, the inserts  70 ,  71  may be connected directly with the gear housing  10 , with the opposite enclosure member provided by the axle housing cover  16 , or held in position by portions of the gear housing features. 
     Referring back to  FIG. 4 , insert  70  has a filter media  130  connected thereto to entrap lubricant contaminants. Insert  71  has a filter  132  which is positioned within its pocket  74 . 
     The present invention has been shown in various embodiments. However, it will be apparent to those skilled in the art of the various modifications and changes which can be made to the invention without departing from the spirit or scope of the invention as it is encompassed by the following claims. This includes, but is not limited to multiple piece construction options.