Patent Publication Number: US-2019168557-A1

Title: Lightweight pusher/tag axle

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. application Ser. No. 15/348,074 filed on Nov. 10, 2016 which claims the benefit, under 35 U.S.C. 119(e), of the provisional application granted Ser. No. 62/263,926 filed on Dec. 7, 2015 and non-provisional application No. 14/938,517 filed on Nov. 11, 2015, the entire disclosures of which are hereby incorporated by reference. 
    
    
     FIELD 
     The present disclosure relates to a non-driven axle for a vehicle or a trailer that reduces the weight of the vehicle or trailer while remaining capable of being lifted without interfering with the operation of a drive axle. 
     BACKGROUND 
     Commercial vehicles or trailers having two or more rear axles allow such vehicles to carry greater loads when compared to vehicles and trailers having a single axle. Further, tractive effort and load distribution can be increased in these vehicles. 
     Any axle beyond one may be a drive axle or a dead axle. When an additional axle is a dead axle, it may be positioned before (a pusher axle) or after (a tag axle) a drive axle. Further, the additional axle may be configured as a lift axle. However, vehicles and trailers including additional axles have many drawbacks as a result of the presence of the additional axles. 
     Conventional installations of additional non-driven axles tend to be heavy. Despite a lack of drive components, such designs still greatly increase the overall weight of the vehicle or trailer. Consequently, the efficiency of the vehicle is negatively affected. 
     When it is desired that an additional non-driven axle is configured as a pusher axle, the axle also must be configured to not interfere with a driveshaft used with the driven axle. Most commonly, the axle is designed to include a “bend” that accommodates a path of the driveshaft. To further complicate the pusher axle configuration, many pusher axles are also configured to be lift axles. When an additional axle is configured as both a pusher and a lift axle, the axle design must accommodate the driveshaft as the non-driven axle moves from a lowered to a raised position. 
     It would be advantageous to develop a non-driven axle for a vehicle or a trailer that reduces the weight of the vehicle or trailer while capable of being lifted without interfering with the operation of a drive axle. 
     SUMMARY 
     A non-driven axle including a first arm portion, a second arm portion, and a substantially U-shaped central portion. The first arm portion has a first wheel hub rotatably mounted thereto. The second arm portion has a second wheel hub rotatably mounted thereto. The second arm portion is on an axial end of the central portion opposite the first arm portion. The substantially U-shaped central portion is positioned between the first arm portion and the second arm portion and includes a main portion and a radially inner portion. The main portion is a hollow, arcuate member having an U-shaped cross-section and the radially inner portion is a substantially U-shaped member disposed against and coupled to an open side of the main portion. 
     In another embodiment, a non-driven axle includes a first arm portion, a second arm portion, and a substantially ring-shaped central portion. The first arm portion has a first wheel hub rotatably mounted thereto. The second arm portion has a second wheel hub rotatably mounted thereto. The second arm portion is on an axial end of the central portion opposite the first arm portion. The substantially ring-shaped central portion is disposed between the first arm portion and the second arm portion. The central portion includes a main portion and a radially inner portion. The main portion is a hollow, ring-shaped member having an U-shaped cross-section and the radially inner portion is disposed within and coupled to the main portion. 
     In yet another embodiment, a non-driven axle includes a first arm portion, a second arm portion, and a substantially ring-shaped central portion where the central portion includes a main portion and an inner ring bearing assembly. The main portion is a hollow, ring-shaped member having an U-shaped cross-section. The inner ring bearing assembly includes a tube portion, a bearing support structure, and a center bearing disposed within and coupled to the main portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above, as well as other advantages of the present embodiments, will become readily apparent to those skilled in the art from the following detailed description when considered in the light of the accompanying drawings in which: 
         FIG. 1A  is a front elevation view of an axle according to one preferred embodiment; 
         FIG. 1B  is a partial, sectional view of the axle shown in  FIG. 1A , along the line  1 B- 1 B of  FIG. 1A ; 
         FIG. 2A  is a side perspective view of an axle and a driveshaft according to another preferred embodiment; 
         FIG. 2B  is a side elevation view of the axle and driveshaft shown in  FIG. 2B ; 
         FIG. 3A  is a side perspective view of an axle and a portion of a section of a jointed driveshaft according to another preferred embodiment; and 
         FIG. 3B  is a side elevation view of the axle and the jointed driveshaft shown in  FIG. 3A , further including a vehicle transmission and a drive axle. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     It is to be understood that the embodiments may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions, directions, orientations or other physical characteristics relating to the embodiments disclosed are not to be considered as limiting, unless expressly stated otherwise. 
       FIG. 1A  illustrates an axle  100  according to a preferred embodiment. The axle  100  is a non-driven axle for use with a vehicle or a trailer. The axle  100  may be configured for use as a pusher or a tag axle. The axle  100  may be in engagement with a lift system  10  for placing and removing the axle  100  from a position where at least two wheels (not shown) rotatably mounted to the axle  100  contact a surface that the vehicle or trailer is traversing. The axle  100  includes a first arm portion  102 , a second arm portion  104 , and a central portion  106 . The central portion  106  connects the first arm portion  102  and the second arm portion  104 . The axle  100 , as depicted, is formed by welding a plurality of cast or forged components together; however, it is understood that the components of the axle  100  may be formed using other processes including, but not limited to, cold working or stamping. The axle  100  is preferably formed from a steel; however, it is understood that other rigid materials may be used. 
     The first arm portion  102  is a hollow, radially extending elongate portion of the axle  100 . As shown in  FIG. 1A , the cross-sectional shape of the first arm portion  102  is circular; however, it is understood that other cross-sectional shapes including, but not limited to, square, rectangular, or oval, may also be used. A distal end  108  of the first arm portion  102  is configured for rotatably mounting a wheel hub (not shown) thereto. A brake flange  110  is securely coupled to the first arm portion  102 , such as through a weld. It is understood that the first arm portion  102  may be configured in another manner, depending on an intended use of the axle  100 . For example, the first arm portion  102  may be configured with a suspension bracket to facilitate engagement with a lift system  10  or an air suspension system (not shown). 
     The second arm portion  104  is a hollow, radially extending, elongate portion of the axle  100  on the axially opposite end of the central portion  106  than the first arm portion  102 . As shown in  FIG. 1A , the cross-sectional shape of the second arm portion  104  is circular; however, it is understood that other cross-sectional shapes including, but not limited to, square, rectangular, or oval, may also be used. A distal end  112  of the second arm portion  104  is configured for rotatably mounting a wheel hub (not shown) thereto. A brake flange  114  is securely coupled to the second arm portion  104 , such as through a weld. It is understood that the second arm portion  104  may be configured in another manner, depending on an intended use of the axle  100 . For example, the second arm portion  104  may be configured with a suspension bracket to facilitate engagement with a lift system  10  or an air suspension system (not shown). 
     The central portion  106  is a hollow, substantially U-shaped assembly connecting the first arm portion  102  and the second arm portion  104 . The central portion  106  projects radially outward and away from the first and second arm portions  102 ,  104 . The central portion  106  includes a main portion  116 , a radially inner portion  118 , and a suspension bracket  120 . The radially inner portion  118  and the suspension bracket  120  are directly coupled to the main portion  116 . The radially inner portion  118  and the suspension bracket  120  may be coupled to the main portion  116  through welding; however, it is understood that other manners of coupling can be used. The radially inner portion  118  has fluid tight seal with the main portion  116 . As shown in  FIGS. 1A and 1B , the central portion  106  can also include at least one reinforcing member  122  disposed between the main portion  116  and the radially inner portion  118 . 
     The main portion  116  is a hollow, arcuate member joining the first arm portion  102  and the second arm portion  104 . As shown in  FIG. 1SA , the main portion  116  may have a substantially arched cross-section that transitions into the cross-sectional shape of the first arm portion  102  at a first transition portion  124 . The arched cross-section also transitions into the cross-sectional shape of the second arm portion  104  at a second transition portion  126 . 
     The radially inner portion  118  is an arched member disposed against and coupled to an open side of the main portion  116 . The radially inner portion  118  is preferably formed from plate steel and is welded to the main portion  116 ; however, it is understood that the radially inner portion  118  may be formed in another manner and coupled to the main portion  116  in any conventional manner. As shown in  FIG. 1B , in one embodiment, the radially inner portion  118  is a flat, plate having a width greater than a width of the main portion  116  providing a surface to which the at least one reinforcing member  122  may be attached to. 
     The reinforcing member  122  can be an arcuate member welded to both the main portion  116  and the radially inner portion  118 ; however, it is understood that a design of the main portion  116  or the radially inner portion  118  may include a similar feature. As shown in  FIGS. 1A-1B , the axle  100  can include two reinforcing members  122   a,    112   b.  The reinforcing member  122   a,    122   b  can be bands that extend along the outer surface of the main portion  116 . Reinforcing members  122   a,    122   b  can be positioned at the intersection of the main portion  116  and the radially inner portion  118  to reinforce the seam created at the intersection. 
     The suspension bracket  120  is a member disposed against and welded to the main portion  116  at a central location radially outward from and radially opposite the radially inner portion  118 . The suspension bracket  120  facilitates engagement between the axle  100  and to a portion of the lift system  10 . Further, the suspension bracket  120  may be configured to engage with an air suspension system (not shown). It is understood that the suspension bracket  120  may also be located on another portion of the axle  100  or that the suspension bracket  120  may include a pair of spaced apart members disposed opposite from one another on the axle  100 . 
     In use, the axle  100  may be utilized as a tag or a pusher axle in a tandem axle assembly (not shown). When utilized as a pusher axle, the axle  100  defines a driveshaft operation area  128  within, radially inward from the radially inner portion  118  and axially between the first arm portion  102  and the second arm portion  104 . The driveshaft operation area  128  provides clearance for the operation of a driveshaft  130  while permitting the axle  100  and an associated drive axle (not shown) to move as part of a vehicle suspension system (not shown). Further, the driveshaft operation area  128  provides clearance between the driveshaft  130  and the axle  100  for a lifting and a lowering of the axle  100  as performed by the lift system  10 . More particularly, the driveshaft operation area  128  provides a predetermined distance between the driveshaft  130  and the axle  100  even when the axle  100  is raised, lowered or moved during vehicle operation. 
     When the axle  100  is configured to provide clearance for lifting and lowering of the axle  100  as performed by the lift system  10 , a control system (not shown) may direct the lift system  10  to operate in response to a detection by a sensor or a plurality of sensors  101  that a load of the vehicle incorporating the axle  100  has changed. The sensors  101  are in communication with the control system that is in communication with the lift system  10 . In one embodiment, the sensors are load sensors  101  including, but not limited to, force sensors arranged on the axle  100  for detecting one or more load indication parameters. 
     As a first non-limiting example, in response to a detected decrease in load by the control system, the lift system  10  may be engaged to place the axle  100  in a lifted condition, where wheels associated with the axle  100  do not engage a surface that the vehicle is traversing. Placing the axle  100  in the lifted condition provides the vehicle the benefits of reduced tire wear for diminished loads, an improvement to a fuel efficiency of the vehicle, and a reduced toll cost (where such toll costs are dependent on a number of engaged axles). Further, as a second non-limiting example, in response to a detected increase in load by the control system, the lift system  10  may be engaged to place the axle  100  in a dropped condition, where wheels associated with the axle  100  engage a surface that the vehicle is traversing. Placing the axle  100  in the dropped condition provides the vehicle the benefits of distributing a load of the vehicle between the axle  100  and a drive axle (not shown). 
       FIGS. 2A and 2B  illustrate an axle  200  according to another preferred embodiment. As shown in  FIGS. 2A and 2B , the axle  200  includes similar components to the axle  100  illustrated in  FIGS. 1A and 1B . Similar features of the embodiment shown in  FIGS. 2A and 2B  are numbered similarly in series, with the exception of the features described below. 
     The axle  200  is a non-driven axle for use with a vehicle or a trailer. The axle  200  may be configured for use as a pusher or a tag axle. The axle  200  may be in engagement with a lift system (not shown) for placing and removing the axle  200  from a position where at least two wheels (not shown) rotatably mounted to the axle  200  contact a surface that the vehicle or trailer is traversing. The axle  200  includes a first arm portion  202 , a second arm portion  204 , and a central portion  230 . The axle  200  is formed by welding a plurality of cast or forged components together; however, it is understood that the components of the axle  200  may be formed using other processes, such as cold working or stamping. The axle  200  is preferably formed from a steel; however, it is understood that other rigid materials may be used. 
     The central portion  230  is a hollow, substantially ring-shaped assembly connecting the first arm portion  202  and the second arm portion  204 . The central portion  230  includes a main portion  232  and a radially inner portion  234 . In one embodiment, as shown in  FIGS. 2A-2B , the radially inner portion  234  is substantially ring-shaped and has a constant thickness. The radially inner portion  234  is welded to an inner surface of the main portion  232 ; however, it is understood that the radially inner portion  234  may be coupled to the main portion  232  in another manner. The radially inner portion  234  has a fluid tight seal with the main portion  232 . 
     The main portion  232  is a hollow, substantially ring-shaped member joining the first arm portion  202  and the second arm portion  204 . The main portion  232  has an arched shaped cross-section that transitions into the cross-sectional shape of the first arm portion  202  at a first transition portion  236 . The U-shaped cross-section also transitions into the cross-sectional shape of the second arm portion  204  at a second transition portion  238 . The main portion  232  defines a driveshaft operation area  240  that extends through the center thereof. An inner surface of the radially inner portion  234  defines an aperture  242  formed therein which defines the driveshaft operation area  240 . 
     The radially inner portion  234  is a ring-shaped member disposed within and welded to the main portion  232 ; however, it is understood that the radially inner portion  234  may be coupled to the main portion  232  in another manner. The radially inner portion  234  has a constant thickness that is substantially equal to or larger than the diameter of the main portion  232 . 
     In use, the axle  200  may be utilized as a tag or a pusher axle in a tandem axle assembly (not shown). When utilized as a pusher axle, the axle  200  defines the driveshaft operation area  240  through the main portion  232  and axially between the first arm portion  202  and the second arm portion  204 . The driveshaft operation area  240  provides clearance for the operation of a driveshaft  244  while permitting the axle  200  and an associated drive axle (not shown) to move as part of a vehicle suspension system (not shown). Further, the driveshaft operation area  240  provides clearance for lifting and lowering of the axle  200  as performed by the lift system (not shown). More particularly, the driveshaft operation area  240  provides a predetermined distance between the driveshaft  244  and the axle  200  even when the axle  200  is raised, lowered or moved during vehicle operation. 
     When the axle  200  is configured to provide clearance for a lifting and a lowering of the axle  200  as performed by the lift system, a control system (not shown) may direct the lift system to operate in response to a detection by a sensor or a plurality of sensors that a load of the vehicle incorporating the axle  200  has changed. The sensors are in communication with the control system which is in communication with the lift system. 
     As a first non-limiting example, in response to a detected decrease in load by the control system, the lift system may be engaged to place the axle  200  in a lifted condition, where wheels associated with the axle  200  do not engage a surface that the vehicle is traversing. Placing the axle  200  in the lifted condition provides the vehicle the benefits of reduced tire wear for diminished loads, an improvement to a fuel efficiency of the vehicle, and a reduced toll cost (where such toll costs are dependent on a number of engaged axles). Further, as a second non-limiting example, in response to a detected increase in load by the control system, the lift system may be engaged to place the axle  200  in a dropped condition, where the wheels associated with the axle  200  engage a surface that the vehicle is traversing. Placing the axle  200  in the dropped condition provides the vehicle the benefits of distributing a load of the vehicle between the axle  200  and a drive axle (not shown). 
       FIGS. 3A and 3B  illustrates an axle  300  (shown in cross-section in  FIG. 3B ) according to another preferred embodiment. The axle  300  includes similar components to the axle  200  illustrated in  FIGS. 2A and 2B . Similar features of the embodiment shown in  FIGS. 3A and 3B  are numbered similarly in series, with the exception of the features described below. The axle  300  is a non-driven axle for use with a vehicle or a trailer. The axle  300  as shown in  FIG. 3A  is configured for use as a pusher axle. The axle  300  may be in engagement with a lift system (not shown) for placing and removing the axle  300  from a position where at least two wheels (not shown) rotatably mounted to the axle  300  contact a surface that the vehicle or trailer is traversing. 
     The axle  300  includes a first arm portion  302 , a second arm portion  304 , and a central portion  350 . The central portion  350  connects the first arm portion  302  and the second arm portion  304 . The axle  300  is formed by welding a plurality of cast or forged components together; however, it is understood that the components of the axle  300  may be formed using other processes including, but not limited to, cold working or stamping. The axle  300  is preferably formed from a steel; however, it is understood that other rigid materials may be used. As shown in  FIG. 3A , the axle  300  includes a center bearing  352  mounted in the axle  300 . A section of a jointed driveshaft  354  is mounted in the center bearing  352 . The jointed driveshaft  354  facilitates driving engagement between a vehicle transmission  356  and a drive axle  358 . 
     The central portion  350  is a hollow, substantially ring-shaped assembly between the first arm portion  302  and the second arm portion  304 . The central portion  350  includes a main portion  360  and an inner ring bearing assembly  362 . A portion of the inner ring bearing assembly  362  is welded to the main portion  360 ; however, it is understood that the inner ring bearing assembly  362  may be coupled to the main portion  360  in another manner. 
     The main portion  360  is a hollow, substantially ring-shaped member joining the first arm portion  302  and the second arm portion  304 . The main portion  360  has an arched shaped cross-section that transitions into the cross-sectional shape of the first arm portion  302  at a first transition portion  364 . The U-shaped cross-section also transitions into the cross-sectional shape of the second arm portion  304  at a second transition portion  366 . The main portion  360  defines a driveshaft operation area  368  through the center thereof therethrough. 
     The inner ring bearing assembly  362  is disposed within and welded to the main portion  360 ; however, it is understood that the inner ring bearing assembly  362  may be coupled to the main portion  360  in another manner. The inner ring bearing assembly  362  includes a radially inner portion  370 , a bearing support structure  372 , and the center bearing  352 . 
     The radially inner portion  370  is a ring-shaped member disposed within and welded to the main portion  360  and the bearing support structure  372 . The radially inner portion  370  has a constant thickness that is substantially equal to or larger than the diameter of the main portion  360 . 
     The bearing support structure  372  is a hollow member having at least two support members  376  extending radially therefrom. The support members  376  are welded to the radially inner portion  370  and a bearing mount  378 . As shown in  FIG. 3B , the bearing support structure  372  includes two support members  376 , but it is understood that another number or a single support member covering an interior of the radially inner portion  370  may also be used. The bearing mount  378  is a hollow member into which the center bearing  352  is disposed. An outer race of the center bearing  352  is engaged with the bearing mount  378  to prevent rotation thereof within the bearing mount  378 , such as through a press fit, but it is understood that other methods and configurations may be used to prevent rotation of the center bearing  352 . Further, the center bearing  352  may be flexibly (but not rotationally) mounted in the bearing mount  378  using an elastomeric material. Flexibly mounting of the center bearing  352  permits the axle  300  to be raised or lowered accounting for any misalignment between the center bearing  352  and the jointed driveshaft  354  during such a process. 
     The center bearing  352  receives a section of the jointed driveshaft  354 . The center bearing  352  is a roller bearing configured for mounting a portion of the jointed driveshaft  354  therein for rotatably supporting the jointed driveshaft  354  during operation of a vehicle the axle  300  is incorporated in. Alternately, the center bearing  352  may be configured as a spherical bearing which permits a portion of the center bearing  352  to rotate with the jointed driveshaft  354  as the axle  300  is raised or lowered. 
     As shown in  FIGS. 3A and 3B , an inner race of the center bearing  352  is engaged with an outer surface of the jointed driveshaft  354  to prevent rotation therebetween, while also allowing the center bearing  352  to move axially along a portion of the section of the jointed driveshaft  354 . In response to the axle  300  being raised or lowered, a position of the center bearing  352  along the jointed driveshaft  354  may need to be adjusted. A plurality of bearings  379  (or similar guide features) are partially disposed in recesses  380  in the inner race of the center bearing  352  and axial races  381  formed in the outer surface of the jointed driveshaft  354 . When the axle  300  is raised or lowered, the bearings  379  rotate within the recesses  380  and move along the axial races  381  in response to movement of the jointed driveshaft  354 . While not shown in  FIGS. 3A and 3B , the jointed driveshaft  354  and the bearing support structure  372  may be fitted with a flexible slip joint cover to ensure that the bearings  379  and the center bearing  352  are operated in a clean environment. 
     In use, the axle  300  is utilized as a pusher axle in a tandem axle assembly (not shown). The axle  300  including the inner ring bearing assembly  362  defines the driveshaft operation area  368  through the main portion  360  and between the first arm portion  302  and the second arm portion  304 . The driveshaft operation area  368  provides clearance for the operation of the jointed driveshaft  354  while permitting the axle  300  and the associated drive axle  358  to move as part of a vehicle suspension system (not shown). Further, the driveshaft operation area  368  provides clearance for a lifting and a lowering of the axle  300  as performed by the lift system (not shown). 
     When the axle  300  is configured to provide clearance for a lifting and a lowering of the axle  300  as performed by the lift system, a control system (not shown) may direct the lift system to operate in response to a detection by a sensor or a plurality of sensors that a load of the vehicle incorporating the axle  300  has changed. The sensors are in communication with the control system which is communication with the lift system. As a first non-limiting example, in response to a detected decrease in load by the control system, the lift system may be engaged to place the axle  300  in a lifted condition, where wheels associated with the axle  300  do not engage a surface the vehicle incorporating the axle  300  is incorporated in is traversing. Placing the axle  300  in the lifted condition provides the vehicle the benefits of reduced tire wear for diminished loads, an improvement to a fuel efficiency of the vehicle, and a reduced toll cost (where such toll costs are dependent on a number of engaged axles). Further, as a second non-limiting example, in response to a detected increase in load by the control system, the lift system may be engaged to place the axle  300  in a dropped condition, where wheels associated with the axle  300  engage a surface the vehicle incorporating the axle  300  is incorporated in is traversing. Placing the axle  300  in the dropped condition provides the vehicle the benefits of distributing a load of the vehicle between the axle  300  and a drive axle (not shown). 
     In accordance with the provisions of the patent statutes, the present designs have been described in what is considered to represent the preferred embodiments. However, it should be noted that these embodiments can be practiced otherwise than as specifically illustrated and described without departing from its scope or spirit.