Abstract:
The invention pertains to a rolling element bearing for a product conveyor and/or product processing element of a harvesting machine, with the bearing including a rolling element chamber and an antechamber, that protects the rolling elements from the penetration of plant juices. A first lubricant feed is provided for supplying lubricant to the rolling elements and a separate second lubricant feed is provided for supplying lubricant to the antechamber.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to rolling element bearings, and more particularly relates to a seal and lubricating arrangement for such bearings.  
         BACKGROUND OF THE INVENTION  
         [0002]    A conveyor roller of a field chopper is described in document DD 121 704 in which several grease chambers are located in front of a bearing in the direction of the conveyor roller, with the bearing being in the form of an adjusting-ring bearing. The grease chambers are used to protect the adjusting-ring bearing against penetration of plant juices that can cause corrosion and destruction of the adjusting-ring bearing. The single grease feed is connected with the central lubricant feed and supplies the adjusting ring bearing with grease that also moves from the adjusting-ring bearing through seals into the grease chamber. In this regard, it is considered to be a disadvantage that the adjusting-ring bearing has to be supplied with a relatively high lubricant pressure so that the grease chamber will be supplied with enough grease. Thus, high grease consumption will result, and the adjusting-ring bearing can be damaged by excessive grease pressure or excessive lubricant.  
         SUMMARY OF THE INVENTION  
         [0003]    According to the present invention, there is provided an improved bearing arrangement for use in a corrosive environment such as that of product conveying and/or product processing elements of a crop harvesting machine.  
           [0004]    A primary object of the invention is to provide a rolling element bearing constructed such that satisfactory lubrication of the antechamber is possible without excessive lubrication of the rolling elements.  
           [0005]    A more specific object of the invention is to provide an improved rolling element bearing having an antechamber protecting the rolling elements against penetration of corrosive fluid, such as plant juices, wherein the antechamber is connected with a first lubricant feed, and the chamber containing the rolling elements is connected with a second lubricant feed. In this manner, the antechamber and the rolling elements, which may be ball bearings, tapered roller bearings or needle bearings, can be separately supplied with lubricant (usually grease). It would also be possible to use sliding bearing elements instead of the rolling bearing elements.  
           [0006]    Another object of the invention is to provide a rolling bearing, as set forth in one or more previous objects, wherein the antechamber is connected to the first lubricant feed via a first duct, while the chamber containing the rolling elements is connected to the second lubricant feed via a second duct having no direct connection with the first duct.  
           [0007]    These and other objects of the invention will become apparent from a reading of the ensuing description together with the appended drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a schematic, left side elevational view of a harvesting machine that is representative of the machines with which the present invention is particularly adapted for use.  
         [0009]    [0009]FIG. 2 is a cross section of a bearing constructed according to the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0010]    A harvesting machine  10 , shown in FIG. 1, as a kind of self-propelled field chopper, is constructed on a chassis  12  that is supported by front and rear pairs of wheels  14  and  16 . Operation of the harvesting machine  10  is done from the operator&#39;s cab  18 , where a crop pickup device  20 , in the form of a corn harvester, is visible. By using the crop pickup device  20 , the product picked up from the ground, e.g., corn, grass or the like, is sent to a chopper drum  22  that chops it into small pieces and moves it to a conveyor device  24 . The product leaves the harvesting machine  10  and passes by means of a rotatable delivery chute  26  to a trailer moving alongside. Between the chopper drum  22  and the conveyor device  24  there is a kernel processor or after-crusher device  28  by means of which the product to be conveyed is supplied tangentially to the conveyor device  24 . The after-crusher device  28  has lower and upper rollers  30  and  32 , respectively, which are rotating in mutually opposing directions.  
         [0011]    One potential problem of the after-crusher device  28  and also of the other product conveyor and/or product processing elements of the harvesting machine  10 , for example, the conveyor device  24  and the intake rollers (not shown) that are located ahead of, and deliver a crop mat to, the chopper drum  22 , is that during conveyance or processing of the crop, plant juices are produced that get into the bearings of the product conveyor and/or product processing elements and can destroy them due to corrosion.  
         [0012]    In order to prevent the penetration of plant juices into the bearing rollers, opposite ends of the lower roller  30  of the after-crusher device  28  are each equipped with a bearing  34  that is illustrated in detail in FIG. 2. Also, the upper roller  32  can be equipped with a bearing  34  of this kind.  
         [0013]    The roller  30  features a hollow cylindrical casing  38  into which an end support ring  40  is inserted. The support ring  40  supports a stub shaft  36 . Between the support ring  40  and the bearing  34  there is a support ring  42  arranged on the stub shaft  36  that is intended to protect the bearing  34  from plant juices. The bearing  34  features an inner ball race  44  that is seated on the stub shaft  36 , and an outer ball race  46  that surrounds the inner ball race  44 . Between the inner ball race  44  and the outer ball race  46  are two rows of balls  48  designed as rolling bearings, with each row of balls being held in a cage  50  and roll in corresponding, opposed sets of axially spaced, curved rolling tracks. The inner ball race  44  is secured to the stub shaft  36  by a clamping ring  52 . The clamping ring  52 , or the part of the stub shaft  36  extending out beyond it to the right in the figure, can also be used for attachment of a belt pulley or of another kind of drive device. The outer ball race  46  is surrounded radially by a bearing housing  54 , which in turn is attached to a side wall  56  of the product conveyor duct of the harvesting machine  10 .  
         [0014]    Between the bearing housing  54  and the inner ball race  44  there is a first seal  58 , in the form of a ring that is connected to the bearing housing  54  and extends radially inward almost to the exterior of the inner ball race  44 . A second seal  60  in the form of a ring extending radially outward from the inner ball race  44 , whose outer region curves axially away from the roller  30 , is spaced axially outward farther from the roller than the first seal  58 . The first seal  58  and the second seal  60  form a labyrinth seal. A third seal  62  with flexible lips  62  resting against the inner ball race  44  in turn is farther from the roller  30  than the second seal  60  and is joined to the outer ball race  46 . The three seals  58 ,  60 ,  62  prevent plant juices from reaching the bearing balls  48 . On the opposite side of the bearing  34  from the roller  30 , there are three additional seals  64 ,  66 ,  68  that are essentially symmetrical with the three seals  58 ,  60 ,  62 . The outer seal  68 , however, is located opposite the clamping ring  52 .  
         [0015]    Between the first seal  58 , the second seal  60  and the third seal  62  there is an annular antechamber  70  that is supplied with grease via a first lubricant feed  72  that is coupled to the antechamber  70  by a duct  74  passing radially through the bearing housing  54 . The balls  48  are supplied with grease via a second lubricant feed  76  coupled to a duct  78  passing radially through the bearing housing  54 . Also, an annular outer antechamber  80  between the three seals  64 ,  66  and  68  is supplied with grease via the second duct  78 , passing through the space between the balls  48  and under the flexible lips of the outer seal  64 . The separate lubricant feeds  72  and  76  make it possible to supply the antechamber  70  and the balls  48  with grease separately, so that the supplied quantities of grease can be measured out according to the particular requirements. The amount of grease can be specified by means of the time interval between lubrications, or by the particular amount of grease supplied. Thus, the antechamber  70  can be supplied with a relatively large amount of grease to compensate for the spent, old grease that is forced out of the antechamber  70  along with the plant juices, whereas the balls  48  receive relatively little grease and at a lower pressure, which will extend their service life. The lubricant feeds  72 ,  76  are preferably connected with a central lubricant supply  82  of the harvesting machine  10 .  
         [0016]    It should be mentioned also that the outer antechamber  80  could be supplied with grease from an associated third lubricant feed and a corresponding separate duct. The lubricant feeds  72  and  76  need not be located diametrically opposite each other, as shown in the figure, but rather can be angularly offset from each other by just a few degrees.  
         [0017]    Having described the preferred embodiment, it will become apparent that various modifications can be made without departing from the scope of the invention as defined in the accompanying claims.