Abstract:
This invention relates to an improved vehicle wheel hub and bearing retention system and method for producing the same, the vehicle wheel hub and bearing retention system including a wheel hub, a bearing unit, and a bearing retention and preload device. The wheel hub includes an inboard end, an outboard end, and a main body. The bearing unit is provided onto a bearing seat of the wheel hub. The material of the inboard end of the wheel hub is re-shaped against the bearing retention and preload device to thereby secure the device on the wheel hub and prevent axial and radial movement of said device relative to the wheel hub. The method for producing a vehicle wheel hub and bearing retention system comprising the steps of: (a) providing a wheel hub defining a longitudinal axis and including an inboard end, an outboard end, and a main body, the wheel hub defining a bearing seat and a wheel hub shoulder; (b) providing a bearing unit onto the bearing seat of the wheel hub adjacent the wheel hub shoulder; (c) providing a bearing unit retention and preload device on the opened inboard end of the wheel hub adjacent the bearing unit; and (d) re-shaping the material of the inboard end of the wheel hub against the bearing unit retention and preload device to thereby secure the bearing unit retention and preload device on the wheel hub and prevent axial movement of the bearing unit relative to the wheel hub.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of Ser. No. 09 328,094 filing date Jun. 8, 1999 now U.S. Pat. No. 6,089,673. 
     This application is a continuation of PCT/US97/22590, filed Dec. 10, 1997, which claims the benefit of U.S. Provisional Application Ser. No. 60/033,453, filed Dec. 10, 1996. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention relates in general to vehicle wheel hub and bearing retention systems and in particular to an improved structure for such a vehicle wheel hub and bearing retention system and method for producing the same. 
     One example of a known vehicle wheel hub and bearing retention system, indicated generally at  10 , is illustrated in prior art FIG.  1 . As shown therein, the prior art vehicle wheel hub and bearing retention system  10  is associated with a wheel (not shown) of a vehicle and includes a wheel hub  12  and a bearing unit  14 . The wheel hub  12  defines a longitudinal axis X and includes a generally stepped body having an opened inboard end  16 , an opened outboard end  18 , and a generally axially extending main body  20  having a radially outwardly extending flange  22 . The wheel hub  12  is provided with a bearing seat  24  for receiving the bearing unit  14 . 
     The flange  22  of the wheel hub  12  has a plurality of circumferentially spaced lug bolt receiving holes  22 A formed therein (only two of such lug bolt receiving holes  22 A are illustrated in FIG.  1 ). A lug bolt  26  is disposed in each of the lug bolt receiving holes  22 A to secure a brake rotor (not shown) and the vehicle wheel to the wheel hub  12  for rotation therewith. The outboard end  18  of the wheel hub  12  is adapted to receive a dust cover (not shown) to prevent dirt, mud, water, and other debris from entering into the interior of the wheel hub  12  through the opened outboard end  18 . 
     The illustrated bearing unit  14  is a pregreased, sealed-for life, one-piece cartridge style bearing pack assembly and includes an outwardly extending flange  28 . The flange  28  has a plurality of circumferentially spaced mounting bolt receiving holes  28 A formed therein (only one of such mounting bolt receiving holes  28 A is illustrated in FIG.  1 ). A mounting bolt (not shown) is disposed in each of the mounting bolt receiving holes  28 A to secure the bearing unit  14  to a non-rotatable component of the vehicle, such as the steering knuckle (not shown), so as to rotatably support the wheel hub  12  relative thereto. 
     A spanner nut  30  is installed on the wheel hub  12  adjacent the opened inboard end  16  thereof to secure the bearing unit  14  on the wheel hub  12  and to preload the bearing unit  14 . As shown in prior art FIG. 3, the spanner nut  30  is a generally annular shaped nut and includes an inner end wall  32 , an outer end wall  34 , an inner cylindrical side wall  36 , and an outer cylindrical side wall  38 . The outer end wall  34  of the spanner nut  30  defines an engagement surface which is oriented generally perpendicular to the longitudinal axis X of wheel hub  12 . The engagement surface  34  is adapted to engage an inboard end surface  14 A of the bearing unit  14  when the spanner nut  30  is installed and tightened on the wheel hub  12 , as will be described below. The spanner nut  30  is preferably formed from stainless steel or carbon steel, and may be electroplated with zinc for corrosion protection. However, the spanner nut  30  can be formed from other materials, such as for example, aluminum. 
     As best shown in prior art FIG. 2, the spanner nut  30  is further provided a plurality of slots  40  (four slots  40  being illustrated in prior art FIG. 2) formed in the outer cylindrical side wall  38 . The slots  40  extend from the inner end wall  32  to the outer end wall  34  of the spanner nut  30  and are adapted to allow a conventional tool (not shown) to be used to tighten the spanner nut  30  on the wheel hub  12 . To accomplish this, the inner cylindrical side wall  36  of the spanner nut  30  is provided with internal threads  36 A. The internal threads  36 A of the spanner nut  30  mate with external threads  12 A provided on the wheel hub  12  adjacent the inboard end  16  thereof As is known, the spanner nut  30  is tightened against the inboard end surface  14 A of the bearing unit  14  to a predetermined torque in order to exert a predetermined clamp load on the bearing unit  14 . 
     The prior art vehicle wheel hub and bearing retention system  10  is subjected to various loads during vehicle operation. Typically, the loads which the prior art vehicle wheel hub and bearing retention system  10  are subjected to include radial loads, bending loads, and torsional loads. Depending on the magnitude of the associated loads and the rotational motion of the associated wheel hub  12  during vehicle operation, the spanner nut  30  can rotate and loosen from its installed position resulting in the loss of the preset bearing preload. Thus, it would be desirable to provide an improved structure for a vehicle wheel hub and bearing retention system which improves the retention of the bearing unit on the wheel hub in order to maintain a preset bearing preload and yet is simple and inexpensive. 
     SUMMARY OF THE INVENTION 
     This invention relates to an improved vehicle wheel hub and bearing retention system and method for producing the same, the vehicle wheel hub and bearing retention system including a wheel hub, a bearing unit, and a bearing retention and preload device. The wheel hub includes an inboard end, an outboard end, and a main body. The bearing unit is provided onto a bearing seat of the wheel hub. The material of the inboard end of the wheel hub is re-shaped against the bearing retention and preload device to thereby secure the device on the wheel hub and prevent axial and radial movement of said device relative to the wheel hub. The method for producing a vehicle wheel hub and bearing retention system comprising the steps of: (a) providing a wheel hub defining a longitudinal axis and including an inboard end, an outboard end, and a main body, the wheel hub defining a bearing seat and a wheel hub shoulder; (b) providing a bearing unit onto the bearing seat of the wheel hub adjacent the wheel hub shoulder; (c) providing a bearing unit retention and preload device on the opened inboard end of the wheel hub adjacent the bearing unit; and (d) re-shaping the material of the inboard end of the wheel hub against the bearing unit retention and preload device to thereby secure the bearing unit retention and preload device on the wheel hub and prevent axial movement of the bearing unit relative to the wheel hub. 
     Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of a portion of a prior art vehicle wheel hub and bearing retention system. 
     FIG. 2 is an elevational view of a prior art spanner nut used on the prior art vehicle wheel hub and bearing retention system of FIG.  1 . 
     FIG. 3 is a sectional view of the prior art spanner nut taken along line  3 — 3  of FIG.  2 . 
     FIG. 4 is a sectional view of a portion of a first embodiment of an improved vehicle wheel hub and bearing retention system constructed in accordance with this invention. 
     FIG. 5 is a sectional view of a portion of the wheel hub shown in FIG. 4 illustrating the structure of the opened inboard end of the wheel hub prior to subjecting the opened inboard end to a metal forming process in accordance with this invention. 
     FIG. 6 is an elevational view of the bearing unit retention and preload device shown in FIG.  4 . 
     FIG. 7 is a sectional view of the bearing unit retention and preload device taken along line  7 — 7  of FIG.  6 . 
     FIG. 8 is a block diagram showing a sequence of steps for producing the improved vehicle wheel hub and bearing retention system shown in FIG.  4 . 
     FIG. 9 is a sectional view of a portion of a second embodiment of an improved vehicle wheel hub and bearing retention system constructed in accordance with this invention. 
     FIG. 10 is a sectional view of a portion of the wheel hub shown in FIG. 9 illustrating the structure of the opened inboard end of the wheel hub prior to subjecting the opened inboard end to a metal forming process in accordance with this invention. 
     FIG. 11 is an elevational view of the bearing unit retention and preload device shown in FIG.  9 . 
     FIG. 12 is a sectional view of the bearing unit retention and preload device taken along line  12 — 12  of FIG.  11 . 
     FIG. 13 is a block diagram showing a sequence of steps for producing the improved vehicle wheel hub and bearing retention system shown in FIG.  9 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to FIGS. 4 through 7, there is illustrated a first embodiment of an improved vehicle wheel hub and bearing retention system, indicated generally at  50 , in accordance with this invention. The illustrated vehicle wheel hub and bearing retention system  50  is associated with a wheel (not shown) of a vehicle. The general structure and operation of the vehicle wheel hub and bearing retention system  50  is conventional in the art. Thus, only those portions of the vehicle wheel hub and bearing retention system  50  which are necessary for a full understanding of this invention will be explained and illustrated in detail. Also, although this invention will be described and illustrated in connection with the particular vehicle wheel hub and bearing retention system  50  disclosed herein, it will be appreciated that this invention may be used in connection with other vehicle wheel hubs and/or bearing assemblies. 
     The illustrated vehicle wheel hub and bearing retention system  50  includes a wheel hub  52  and a bearing unit  54 . The wheel hub  52  defines a longitudinal axis Z and includes a generally stepped body having an opened inboard end  56 , an opened outboard end  58 , and a generally axially extending main body  60 . 
     The main body  60  of the wheel hub  52  is provided with a radially outwardly extending flange  62  and a bearing seat  64  for receiving the bearing unit  54 . The flange  62  of the wheel hub  52  includes a plurality of circumferentially spaced lug bolt receiving holes  62 A formed therein (only two of such lug bolt receiving holes  62 A are illustrated in FIG.  4 ). A lug bolt  66  is disposed in each of the lug bolt receiving holes  62 A to secure a brake rotor (not shown) and a vehicle wheel (not shown) to the wheel hub  52  for rotation therewith. The opened outboard end  58  of the wheel hub  52  is adapted to receive a dust cover (not shown) to prevent dirt, mud, water, and other debris from entering into the interior of the wheel hub  52  through the opened outboard end  58 . 
     As shown in FIG. 5, the wheel hub  52  is initially provided with a reduced diameter non-threaded section  70  directly adjacent the opened inboard end  56  thereof. The wheel hub section  70  has a generally constant thickness T, defines a predetermined outer diameter D 1 , and extends a predetermined axial distance X 1 . The wheel hub  52  is further provided with a section  72  directly adjacent the section  70 . The section  72  of the wheel hub  52  is provided with external threads  72 A. Also, the structure of the non-threaded wheel hub section  70  can be other than illustrated if desired. 
     The illustrated bearing unit  54  is a pregreased, sealed-for life non-serviceable cartridge style bearing pack assembly and is pressed onto the bearing seat  64  of the wheel hub  52 . The bearing unit  54  includes an outer race  54 A, a pair of inner races  54 B and  54 C, and a plurality of bearings  54 D and  54 E, shown in this embodiment as tapered roller bearings, installed between the inner races  54 B and  54 C and the outer race  54 A. However, the bearing unit  54  can be other than illustrated if desired. 
     The outer race  54 A of the bearing unit  54  includes an radially outwardly extending flange  68  having a plurality of circumferentially spaced mounting bolt receiving holes  68 A formed therein (only one of such mounting bolt receiving holes  68 A is illustrated in FIG.  4 ). A mounting bolt (not shown) is disposed in each of the mounting bolt receiving holes  68 A to secure the bearing unit  54  to a non-rotatable component of the vehicle, such as the steering knuckle (not shown), so as to rotatably support the wheel hub  52  relative thereto. 
     A bearing unit retention and preload device, indicated generally at  78 , is installed on the wheel hub  52  adjacent the inboard end  56  thereof to secure and preload the bearing unit  54  on the wheel hub  52 . In the illustrated embodiment, the bearing unit retention and preload device  78  includes a generally annular retention nut  80 . As shown in FIG. 7, the retention nut  80  includes an inner end wall  82 , an outer end wall  84 , an inner cylindrical side wall  86 , and an outer cylindrical side wall  88 . The outer end wall  84  of the retention nut  80  defines an engagement surface which is oriented generally perpendicular to the longitudinal axis Z of wheel hub  52 . The engagement surface  84  of the retention nut  80  is adapted to engage an inboard end surface  54 F of the bearing unit  54  when the retention nut  80  is installed and tightened on the wheel hub  52 , as will be described below. The retention nut  80  is preferably formed from stainless steel or carbon steel, and may be electroplated with zinc for corrosion protection. However, the retention nut  80  can be formed from other materials, such as for example, aluminum. 
     In the illustrated embodiment, the retention nut  80  is provided with a plurality of slots  90  (four slots  90  being illustrated in FIG. 6) formed in the outer cylindrical side wall  88 . The slots  90  extend from the inner end wall  82  to the outer end wall  84  of the retention nut  80  and are adapted to allow a conventional tool to be used to install and tighten the retention nut  80  on the wheel hub  52 . To accomplish this, the inner cylindrical side wall  86  of the retention nut  80  is provided with internal threads  86 A. The internal threads  86 A of the retention nut  80  mate with the external threads  72 A provided on the section  70  of the wheel hub  52 . As is known, the retention nut  80  is tightened against the inboard end surface  54 F of the bearing unit  54  to a predetermined torque in order to exert a predetermined clamp load on the bearing unit  54 . 
     In the illustrated embodiment, the retention nut  80  preferably further includes a plurality of indentations or notches  92  (four equidistantly spaced indentations  92  being illustrated in FIG. 6) provided therein. As shown in FIG. 7, the indentations  92  extend radially outwardly from the inner cylindrical side wall  86 , and axially inwardly from the inner end wall  82  toward the outer end wall  84 . Alternatively, the number, spacing, and/or the configuration of the indentations  92  can be other than illustrated if desired. As will be discussed, the indentations  92  are adapted to allow the material of the wheel hub  52  to be displaced therein in order to positively lock the retention nut  80  in place on the wheel hub  52 . 
     Turning now to FIG. 8, the method for producing the vehicle wheel hub and bearing retention system  50  of this invention will be discussed. Initially, in step  100 , the bearing unit  54  is pressed onto the bearing surface  64  of the wheel hub  52  and advanced (to the right in FIG. 4) until the inner race  54 C engages a wheel hub shoulder  52 A. Next, in step  102 , the retention nut  80  is installed on the non-threaded section  70  of the opened inboard end of the wheel hub  52  (the shape of the section  70  of the inboard end of the wheel hub  52  being shown in FIG. 5 when the retention nut  80  is initially installed during step  102 ). During step  102 , the retention nut  80  is advanced (to the right in FIG. 4) to the threaded section  72 A and is threadably tightened thereon to exert a predetermined clamp load on the bearing unit  54  as described above. Following this, in step  104 , the section  70  of the opened inboard end of the wheel hub  52  (shown in phantom in FIG. 4 prior to performing step  104 ), is subjected to a metal forming process to secure the retention nut  80  thereon and produce the vehicle wheel hub and bearing retention system  50  of this invention. 
     To accomplish this, the wheel hub  52  is supported on a suitable fixture not shown) and a metal forming tool  110  (shown in phantom in FIG. 4) is provided. The metal forming tool  110  is oriented at an angle A relative to the axis Z of the wheel hub  52  and is mounted on a support member (not shown) which allows the metal forming tool  110  to be selectively movable toward (and away from) the wheel hub  52 . As will be discussed, the metal forming tool  110  is provided with a tool end  110 A having a predetermined contour which is effective to impart a predetermined contour to the section  70  of the wheel hub  52  during step  104 . 
     During the metal forming process of step  104 , an end  70 A of section  70  of the wheel hub  52  is engaged by the tool end  110 A of the metal forming tool  110 . As the forming tool  110  is orbited or moved (as shown by arrow R), the material of the section  70  of the wheel hub  52  is engaged and reshaped generally radially outwardly by the tool end  100 A against the adjacent inner end wall  82  of the retention nut  80  to produce the final shape of the opened inboard end  56  of the wheel hub  52  shown in FIG.  4 . During step  104 , the forming tool  110  is operative to increase the radial dimension of the section  70  of the wheel hub  52  to form a predetermined finished section  56  of the wheel hub  52  which generally corresponds to the shape of the tool end  110 A. As a result, the metal forming process of step  104  secures the retention nut  80  on the wheel hub  52 . Also, during the metal forming process of step  104 , the material of the section  70  of the wheel hub  52  is displaced into and fills the indentations  90  of the retention nut  80 , thereby providing a positive mechanical lock of the retention nut  80  on the wheel hub  52 . Alternatively, other metal forming processes can be used if desired. 
     Turning now to FIGS. 9-13 and using like reference numbers to indicate corresponding parts, a second embodiment of an improved vehicle wheel hub and bearing retention system, indicated generally at  50 ′, and method for producing the same in accordance with this invention will be discussed. 
     The vehicle wheel hub and bearing retention system  50 ′ includes a bearing unit retention and preload device, indicated generally at  78 ′, installed on the wheel hub  52 ′ to secure and preload the bearing unit  54  thereon. In the illustrated embodiment, the bearing unit retention and preload device  78 ′ includes a generally annular retention ring  80 ′. 
     As shown in FIG. 12, the retention ring  80 ′ includes an inner end wall  82 ′, an outer end wall  84 ′, an inner cylindrical side wall  86 ′, and an outer cylindrical side wall  88 ′. The outer end wall  84 ′ of the retention ring  80 ′ defines an engagement surface which is oriented generally perpendicular to the longitudinal axis Z of wheel hub  52 ′. The engagement surface  84 ′ of the retention ring  80 ′ is adapted to engage an inboard end surface  54 F of the bearing unit  54  when the retention ring  80 ′ is installed and tightened on the wheel hub  52 ′, as will be described below. The inner cylindrical side wall  86 ′ of the retention ring  80 ′ defines a retention ring inner diameter D 4 . The retention ring  80 ′ is preferably formed from a material which is harder than material of the inner race  54 B of the bearing unit  54 . Also, the retention ring  80 ′ is preferably formed from stainless steel or carbon steel, and may be electroplated with zinc for corrosion protection. However, the retention ring  80 ′ can be formed from other materials, such as for example, aluminum. 
     In the illustrated embodiment, the retention ring  80 ′ can be provided with a plurality of indentations  92 ′ (four equidistantly spaced indentations  92 ′ being illustrated in FIG. 11 in phantom) provided therein. As shown in FIG. 12, the indentations  92 ′ extend radially outwardly from the inner cylindrical side wall  86 ′, and axially inwardly from the inner end wall  82 ′ toward the outer end wall  84 ′. Alternatively, the retention ring  80 ′ does not have to include the indentations  92 ′, or the number, spacing, and/or the configuration of the indentations  92 ′ can be other than illustrated if desired. As will be discussed, the indentations  92 ′ are adapted to allow the material of the wheel hub  52 ′ to be displaced therein in order to positively lock the retention ring  80 ′ in place on the wheel hub  52 ′. 
     Turning now to FIG. 13, the method for producing the vehicle wheel hub and bearing retention system  50 ′ of this invention will be discussed. Initially, in step  100 ′, the bearing unit  54  is pressed onto the bearing surface  64 ′ of the wheel hub  52 ′ and advanced thereon (to the right in FIG. 9) until the inner race  54 C engages a wheel hub shoulder  52 A′. Next, in step  102 ′, the retention ring  80 ′ is installed on the non-threaded section  70 ′ of the opened inboard end of the wheel hub  52 ′ (the shape of the section  70 ′ of the inboard end of the wheel hub  52 ′ being shown in FIG. 10 when retention ring  80 ′ is initially installed during step  102 ′). Preferably, to accomplish this, the retention ring inner diameter D 4  is slightly greater than the outer diameter D 1 ′ of the section  70 ′ of the wheel hub  52 ′ so as to provide a slip-fit or clearance-fit of the retention ring  80 ′ thereon. Alternatively, the retention ring inner diameter D 4  can be slightly less than or generally equal to the outer diameter D 1 ′ of the wheel hub  52 ′ so as to provide a press-fit thereon. 
     Next, in step  104 ′, the section  70 ′ of the opened inboard end of the wheel hub  52 ′ (shown in phantom in FIG. 9 prior to performing step  104 ′), is subjected to a metal forming process to secure the retention ring  80 ′ thereon and to simultaneously preload the bearing unit  54 ′ and thereby produce the vehicle wheel hub and bearing retention system  50 ′ of this invention. 
     To accomplish this, the wheel hub  52 ′ is supported on a suitable fixture (not shown) and a metal forming tool  110  (shown in phantom in FIG. 9) is provided. The metal forming tool  110  is oriented at an angle A relative to the axis Z of the wheel hub  52 ′ and is mounted on a support member (not shown) which allows the metal forming tool  110  to be selectively movable toward (and away from) the wheel hub  52 ′. As will be discussed, the metal forming tool  110  is provided with a tool end  110 A having a predetermined contour which is effective to impart a predetermined contour to the section  70 ′ of the wheel hub  52  during step  104 ′. 
     During the metal forming process of step  104 ′, an end  70 A′ of section  70 ′ of the wheel hub  52 ′ is engaged by the tool end  110 A of the metal forming tool  110 . As the forming tool  110  is orbited (as shown by arrow R), the material of the section  70 ′ of the wheel hub  52 ′ is engaged and reshaped generally radially outwardly by the tool end  100 A against the adjacent inner end wall  82 ′ of the retention ring  80 ′ to produce the final shape of the opened inboard end  56 ′ of the wheel hub  52 ′ shown in FIG.  9 . During step  104 ′, the forming tool  110  is operative to increase the radial dimension of the section  70 ′ of the wheel hub  52 ′ and to form a predetermined finished section  56 ′ of the wheel hub  52 ′ which generally corresponds to the shape of the tool end  110 A. As a result, the metal forming process of step  104 ′ secures the retention ring  80 ′ on the wheel hub  52 ′. Also, in this embodiment, during step  104 ′, the metal forming process is selectively controlled so that the retention ring  80 ′ is operative to exert a predetermined clamp load on the bearing unit  54 . Thus, step  104 ′ is operative to secure the retention ring  80 ′ on the wheel hub  52 ′ and to simultaneously preload the bearing unit  54 . In addition, during the metal forming process of step  104 ′, the material of the section  70 ′ of the wheel hub  52 ′ is displaced into and fills the indentations  90 ′ of the retention ring  80 ′ thereby providing a positive mechanical lock of the retention ring  80 ′ on the wheel hub  52 ′. Alternatively, other metal forming processes can be used if desired. 
     One advantage of this invention is that the metal forming process is operative to positively secure the bearing unit retention and preload device  78  and  78 ′ on the respective wheel hub  52  and  52 ′ in a predetermined installed position and prevent axial and radial movement of the device relative thereto. As a result, the bearing unit retention and preload device  78  and  78 ′ of this invention is operative to maintain the predetermined clamp load against the associated bearing unit  54 . Another advantage of this invention is that since the bearing unit  54  is preferably a non-serviceable bearing unit, the metal forming process of the section  70  and  70 ′ of the respective wheel hub  52  and  52 ′ against the bearing unit retention and bearing preload device  78  and  78 ′ produces a tamper-proof wheel hub and bearing retention assembly  50  and  50 ′. 
     In accordance with the provisions of the patent statutes, the principle and mode of operation of this invention have been described and illustrated in its preferred embodiments. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.