Patent Publication Number: US-2009217493-A1

Title: Hoop retaining ring

Description:
RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/032,311, to Michael Greenhill, entitled “Hoop Retaining Ring,” filed on Feb. 28, 2008, currently pending. 
    
    
     BACKGROUND 
     The present technology generally relates to retaining rings that can be used either externally on a shaft or internally within a bore. 
     Generally, retaining rings are fastening devices that fit on a shaft or in a bore to retain components in an axial position on the shaft or in the bore where they are situated. There are several types of retaining rings. Examples of retaining rings include “circlips” that are stamped from sheet or strip metal, “spiral” retaining rings that can be single or multiple turns and are formed from flat wire, “round wire” retaining rings formed from round wire, and others. Retaining rings conventionally have an axial thickness that is smaller than their radial width. This means that the distance that such clips extend in a direction perpendicular to the shaft, the radial width, is greater than the distance they extend along the shaft, the axial thickness. 
     Conventional retaining rings are positioned in a groove that has been machined into the exterior surface of a shaft or the interior surface of a bore. The ring, as installed in its operating position in the groove, forms a shoulder that components ride up against, thereby, preventing the components from moving axially past the ring. Conventional retaining rings are designed to accommodate thrust loads in a purely axial direction. 
     Retaining rings are preferably removable. Accordingly, components on a shaft that are held in position by a retaining ring may be removed from the shaft by first removing the retaining ring and then sliding the components past the groove in which the retaining ring was positioned. 
     The design of a groove in which a retaining ring will be positioned is generally determined by the configuration of the retaining ring selected. For example, a conventional retaining ring is seated in a groove that is typically a depth of approximately 30%-50% of the retaining ring&#39;s radial width. Retaining rings seated in such a groove typically extend radially above a shaft, or within a bore, a distance of approximately 50%-70% of the retaining ring&#39;s radial width. 
     In general applications, the thrust capacity of a retaining ring that is installed in its groove increases as the depth of the groove increases. The main reason is grooves that are more shallow tend to result in the ring twisting or dishing as load is applied.  FIG. 3 , for example, illustrates a typical retaining ring  32 , in a groove on a shaft  30 , with a thrust load being applied by a component  34 . As the component  34  applies a thrust load to the retaining ring  32 , the ring shifts to the position  32   a , resulting in axial shift of the component  34  by an amount X. The groove continues to deform rapidly as load is further applied to the ring, increasing the dishing of the ring that eventually contacts and mushrooms the groove wall causing failure as the ring extrudes out. Deformation of the groove wall is illustrated, for example, in  FIG. 7 . As shown, a component  72  is applying a thrust load to retaining ring  74 , which is positioned in a groove in shaft  70 . The retaining ring  74  is dishing by an amount D, causing a deformation  76  in the shaft. Such dishing is the most common failure mode of any rectangular section retaining ring. Groove deformation, such as that illustrated in  FIG. 7 , can occur in instances where the shaft or bore is formed of materials such as aluminum, cold rolled steel, low carbon or mild steel or other softer materials. In situations like this, design engineers will often specify custom rings made specifically for deeper grooves or rings with an increased thickness to fit into wider grooves, thereby providing increased thrust capacity. Such rings are much harder to remove from the groove and are often damaged when removing or reinstalling 
     One option for mechanical designers is to increase the depth of the groove to maximize thrust capacity of the assembly. The trade-off is that increased groove depth results in decreased shaft wall thickness at the retaining ring position, thus weakening the shaft. In many applications, the groove depth is restricted by the size of the shaft and the construction of the shaft. In the case of a thin walled sleeve, the radial cross-section of the shaft (i.e. the wall of the tube) would limit the depth of the groove. In this situation, designers are often prevented from using retaining rings because rings are often designed for grooves that would be too deep for the application. Sometimes engineers design special retaining rings for use in such applications, which tends to result in limiting thrust capacity. 
     Many ring manufacturers offer a choice of retaining rings for different thrust capacities. In the situation of a light duty application, the groove depth would be shallower than for other rings designed to handle higher thrust capacity. Groove standards were established many years ago by U.S. military and aircraft specifications Many retaining ring manufacturers adopted these specifications for imperial ring manufacturing. DIN Standards for retaining ring grooves were also established years ago in Europe as European engineering standards, and many OEM&#39;s have adopted these metric specifications as standard. In either standard, the retaining rings and grooves are designed to handle heavy thrust loads. This being the case, the majority of retaining rings specified worldwide are designed using the established world standards for heavy thrust capacity applications. 
     Components being retained on a shaft, or within a bore, generally have a radial width that is greater than the radial section of the retaining ring that extends radially beyond the shaft or bore in which the retaining ring is seated. The surface of the component that contacts the ring is often flat and presses evenly across the entire radial section of the retaining ring. In some applications, however, the component that presses against the retaining ring may not be even, or may have a radius or chamfer that doesn&#39;t press evenly against the radial section of the ring. Examples of such situations include times when a component has a chamfered or radiused edge, and when the component is not concentric to the shaft or bore such that there is a clearance between the two components. As illustrated in  FIG. 1 , for example, a retaining ring  12  is positioned in a groove on shaft  10 , and a component  14  having a chamfered edge is in contact with the retaining ring  12 . In  FIG. 2 , a retaining ring  22  is in a groove on shaft  20 , and a component  24  having a radiused edge is in contact with the retaining ring  22 . In  FIG. 4 , a retaining ring  42  is in a groove on a shaft  40 , with component  44  in contact with the retaining ring. There is a clearance C between the component  44  and the shaft  40 .  FIG. 5  illustrates a retaining ring  52  in a groove on a shaft  50 , and a component  54  in contact with the retaining ring  52 . The sides of the groove in the shaft  50  are uneven, resulting in a step of an amount S between one side of the groove and the other. In each of the situations illustrated in  FIGS. 1 ,  2 ,  4  and  5 , a moment arm can result, which tends to dish the ring and cause ring failure. Generally, the objective of a mechanical design is to avoid such conditions. 
     The shaft material, and thus the strength of the groove wall, also plays a role in design assemblies utilizing retaining rings. About 95% of applications tend to utilize heat-treated and hardened retaining rings in groove materials that are significantly softer than the ring material. In instances where the shaft or bore is formed of hardened material, such as hardened steel, ring shear can occur.  FIG. 6  illustrates an example of ring shear. As illustrated in  FIG. 6 , ring  64 , positioned in a groove on shaft  60  made of hardened steel, has sheared due to the thrust load applied to the ring  64  by component  62 . In such instances, as external force is applied to the ring  64  by the component  62 , the ring  64  can start to dish, but the hardened material of the shaft  60  does not deform or mushroom like soft steel tends to under such circumstances. When the force applied by the component  62  becomes sufficiently high, the retaining ring  64  can shear. 
     BRIEF SUMMARY 
     The present technology generally relates to retaining rings that can be used either externally on a shaft or internally within a bore. Such retaining rings can be utilized to retain a component adjacent to a shaft or bore, thus forming an assembly. 
     In one aspect a retaining ring for use externally on a shaft or internally within a bore is provided, the retaining ring including a rectangular cross-section having an axial thickness and a radial width, where the axial thickness is greater than the radial width. 
     In another aspect, an assembly utilizing a retaining ring to retain a component adjacent to a shaft or bore is provided that includes a groove for receiving a retaining ring, a retaining ring received within the groove, and an adjacent component in contact with the retaining ring that is retained adjacent to the shaft or bore by the retaining ring. The groove can be located on a shaft or in a bore. The retaining ring can include a rectangular cross-section having an axial thickness and a radial width, where the axial thickness greater than the radial width. 
    
    
     
       BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS 
       Specific examples have been chosen for purposes of illustration and description, and are shown in the accompanying drawings, forming a part of the specification. 
         FIG. 1  is a cross-sectional view of a known retaining ring positioned in a groove on a shaft in contact with a chamfered component. 
         FIG. 2  is a cross-sectional view of a known retaining ring positioned in a groove on a shaft in contact with a radiused component. 
         FIG. 3  is a cross-sectional view of a known retaining ring positioned in a groove on a shaft in contact with a component, where the retaining ring is dishing. 
         FIG. 4  is a cross-sectional view of a known retaining ring positioned in a groove on a shaft in contact with a chamfered component, where there is a clearance between the shaft and the component. 
         FIG. 5  is a cross-sectional view of a known retaining ring positioned in a groove on a shaft in contact with a chamfered component, where the groove includes a step. 
         FIG. 6  is a cross-sectional view of a known retaining ring positioned in a groove on a shaft in contact with a component, where the ring has sheared. 
         FIG. 7  is a cross-sectional view of a known retaining ring positioned in a groove on a shaft in contact with a component, where the groove has become deformed. 
         FIG. 8  is a perspective view of one embodiment of a retaining ring of the present technology positioned in a groove on a shaft. 
         FIG. 9A  is a top elevational view of one embodiment of a retaining ring of the present technology that can be utilized in a groove on a shaft. 
         FIG. 9B  is a side elevational view of the retaining ring of  FIG. 9A . 
         FIG. 10  is a perspective view of one embodiment of a retaining ring of the present technology positioned in a groove in a bore. 
         FIG. 11A  is a top elevational view of one embodiment of a retaining ring of the present technology that can be utilized in a groove in a bore. 
         FIG. 11B  is a side elevational view of the retaining ring of  FIG. 11A . 
         FIG. 12A  is a cross-sectional view of one embodiment of a retaining ring of the present technology positioned in a groove on a shaft in contact with a chamfered component. 
         FIG. 12B  is a cross-sectional view of the retaining ring of  FIG. 12A , showing the directional components of the thrust exerted by the component. 
         FIG. 13  is a cross-sectional view of one embodiment of a retaining ring of the present technology positioned in a groove on a shaft in contact with a radiused component. 
         FIG. 14  is a cross-sectional view of one embodiment of a retaining ring of the present technology positioned in a groove on a shaft in contact with a square edged component. 
         FIG. 15  is a cross-sectional view of one embodiment of a retaining ring of the present technology positioned in a groove on a shaft in contact with a component that overhangs the retaining ring. 
         FIG. 16  is a perspective view of one embodiment of a retaining ring of the present technology positioned in a groove on a shaft. 
         FIG. 17A  is a perspective view of one embodiment of a retaining ring of the present technology. 
         FIG. 17B  is a top elevational view of the retaining ring of  FIG. 17A . 
     
    
    
     DETAILED DESCRIPTION 
     Retaining rings are generally used by positioning them in a groove that is located on a shaft or within a bore. In various applications, retaining rings can be utilized to retain a component adjacent to a shaft or bore, thus forming an assembly. Such assemblies can include a groove for receiving a retaining ring, the groove being located on a shaft or in a bore, a retaining ring, and a component in contact with the retaining ring that is retained adjacent to the shaft or bore by the retaining ring. 
     In preferred embodiments, the retaining rings disclosed herein have a smaller radial profile than conventional retaining rings, and can be positioned in grooves having shallower depths. Preferably, thrust loads applied to the retaining rings disclosed herein have both an axial and a radial component. 
     The unique retaining rings of the present technology preferably have a rectangular cross-section having an axial thickness, in a direction along the shaft or bore, and a radial width, in a direction perpendicular to the shaft or bore. The axial thickness of the retaining rings is greater than the radial width. 
       FIGS. 8 ,  9 A and  9 B illustrate some embodiments of external retaining rings for installation in a groove on a shaft.  FIG. 8  shows an external retaining ring  82  positioned in a groove on a shaft  80 . Shaft  80  is cylindrical, and has a groove extending around its circumference to receive the retaining ring  82 .  FIGS. 9A and 9B  show an external retaining ring  90  that can also be positioned in a groove on a shaft. Retaining ring  90  has a first end  91 , a second end  92  that is separated from the first end by a distance  93 , a radial width  94 , and an axial thickness  96 . The axial thickness  96  of the retaining ring  90  is greater than the radial width  94  of the retaining ring  90 . The retaining ring is circular, or substantially circular, in shape, to fit within a groove on a cylindrical shaft, and the retaining ring  90  has an inner diameter  95 . The inner diameter  95  of the external retaining ring  90  can be sized to fit the diameter of the groove on the shaft, and preferably forms a tight or snug fit in the groove. 
     The retaining ring  90  can have any dimensions suitable for the intended application. In some example, retaining ring  90  can be formed from one turn of metal having a rectangular cross section. In a first example, the retaining ring  90  can have a radial thickness of from about 0.0235 inches to about 0.0265 inches, an axial thickness of from about 0.084 inches to about 0.092 inches, a separation between the first end  91  and the second end  92  of from about 0.015 inches to about 0.065 inches, and an inner diameter of from about 0.696 inches to about 0.711 inches. A retaining ring  90  having such dimensions can be utilized, for example, on a shaft having a diameter of about 0.75 inches, with a groove having a groove diameter of about 0.726 inches and a minimum groove axial thickness of about 0.093 inches. In a second example, the retaining ring  90  can have a radial thickness of from about 0.033 inches to about 0.037 inches, an axial thickness of from about 0.146 inches to about 0.154 inches, a separation between the first end  91  and the second end  92  of from about 0.020 inches to about 0.090 inches, and an inner diameter of from about 1.416 inches to about 1.436 inches. A retaining ring  90  having such dimensions can be utilized, for example, on a shaft having a diameter of about 1.5 inches, with a groove having a groove diameter of about 1.466 inches and a minimum groove axial thickness of about 0.156 inches. In a third example, the retaining ring  90  can have a radial thickness of from about 0.044 inches to about 0.048 inches, an axial thickness of from about 0.220 inches to about 0.230 inches, a separation between the first end  91  and the second end  92  of from about 0.025 inches to about 0.150 inches, and an inner diameter of from about 2.865 inches to about 2.895 inches. A retaining ring  90  having such dimensions can be utilized, for example, on a shaft having a diameter of about 3 inches, with a groove having a groove diameter of about 2.955 inches and a minimum groove axial thickness of about 0.232 inches. 
       FIGS. 10 ,  11 A and  11 B illustrate some embodiments of internal retaining rings for installation in a groove within a bore.  FIG. 10  shows a cut-away of a bore  102 , and an internal retaining ring  100  positioned in a groove within the bore  102 .  FIGS. 11A and 11B  show an internal retaining ring  110  that can also be positioned in a groove in a bore. Retaining ring  110  has a first end  112 , a second end  114  that is separated from the first end by a distance  116 , a radial width  118 , and an axial thickness  122 . The axial thickness  122  of the retaining ring  110  is greater than the radial width  118  of the retaining ring  110 . The retaining ring  110  is circular, or substantially circular, in shape, to fit within a groove in a cylindrical bore, and the retaining ring  110  has an outer diameter  120 . The outer diameter  120  of the internal retaining ring  110  can be sized to fit within the circumferential dimension of the groove in the bore. 
     The retaining ring  110  can have any dimensions suitable for the intended application. In some examples, retaining ring  110  can be formed from one turn of metal having a rectangular cross section. In a first example, the retaining ring  110  can have a radial thickness of from about 0.0235 inches to about 0.0265 inches, an axial thickness of from about 0.084 inches to about 0.092 inches, a separation between the first end  112  and the second end  114  of from about 0.015 inches to about 0.065 inches, and an outer diameter of from about 0.789 inches to about 0.804 inches. A retaining ring  110  having such dimensions can be utilized, for example, in a bore having an inner diameter of about 0.75 inches, with a groove having a groove diameter of about 0.774 inches and a minimum groove axial thickness of about 0.093 inches. In a second example, the retaining ring  110  can have a radial thickness of from about 0.0235 inches to about 0.0265 inches, an axial thickness of from about 0.084 inches to about 0.092 inches, a separation between the first end  112  and the second end  114  of from about 0.015 inches to about 0.065 inches, and an outer diameter of from about 1.044 inches to about 1.064 inches. A retaining ring  110  having such dimensions can be utilized, for example, on a shaft having a diameter of about 1.0 inches, with a groove having a groove diameter of about 1.024 inches and a minimum groove axial thickness of about 0.093 inches. In a third example, the retaining ring  110  can have a radial thickness of from about 0.033 inches to about 0.037 inches, an axial thickness of from about 0.146 inches to about 0.154 inches, a separation between the first end  112  and the second end  114  of from about 0.020 inches to about 0.090 inches, and an outer diameter of from about 1.564 inches to about 1.584 inches. A retaining ring  110  having such dimensions can be utilized, for example, on a shaft having a diameter of about 1.5 inches, with a groove having a groove diameter of about 1.534 inches and a minimum groove axial thickness of about 0.156 inches. 
     Preferred embodiments of retaining rings have a natural spring tension, or radial force, to facilitate the ring seating itself in a groove. The stability of a retaining ring can be increased by increasing its axial thickness, which increases the natural spring tension of the retaining ring. However, as ring stability increases, the flexibility decreases. A desired level of stability and flexibility can be achieved so that the retaining ring retains its position in a groove, but is also sufficiently flexible so that it can be easily installed and removed. Some examples of preferred retaining rings can have a ratio of axial thickness to radial width of about 20:1 or less, and preferably about 3:1 or greater. Ratios over 3:1 can increase the stability of the retaining ring, but an increase in the axial thickness results in an increase in the groove thickness required to receive the retaining ring. 
     Additionally, it is preferred that retaining rings of the present technology be circular, or substantially circular, in order to fill as much of the groove depth as possible. In some examples, a minimum of 85% of the circumference of the retaining ring can have a maximum standoff between the ring and the groove of up to about 0.002 inches. In other examples, a maximum of 15% of the circumference of the retaining ring can have a maximum standoff between the ring and the groove of up to about 0.004 inches. 
     The preferred groove depth for retaining rings disclosed herein can be significantly less than groove depths normally associated with conventional retaining rings. Accordingly, retaining rings of the present technology can be mounted or positioned in a relatively shallow groove. Conventionally, it is common practice to specify a groove depth of from about 30% to about 50% of a conventional retaining ring&#39;s radial width. The same specification can be utilized with retaining rings of the present technology. However, because the radial width of the current retaining rings can be substantially less than the radial width of conventional retaining rings, the resultant groove depth can be substantially reduced as compared to conventional groove depths. The shallow groove depth that can be utilized to mount retaining rings of the present technology can provide significant advantages in thin walled sleeves. In at least one example, where groove depth is calculated at a 50% value, a 1 inch diameter retaining ring can extend about 0.012 inches radially above a shaft or bore and about 0.012 inches deep forming the groove depth. Because the groove is shallow, there is not the conventional amount of groove depth to seat the ring in position. Accordingly, it is preferred that the corners of the groove be sharply defined, so that the retaining ring can be seated properly in a manner that abuts a substantial portion of the groove wall, and preferably the entire groove wall. 
     Retaining rings of the present technology do not tend to dish or twist when force is applied, which can allow for much greater thrust capacity of the assembly in which the retaining ring is installed. Without being bound by any particular theory, it is believed that the mechanical advantage created by the form of the retaining rings of the present technology resists dishing, and that the moment arm of a conventional retaining ring can be significantly reduced or eliminated such that the thrust capacity depends at least primarily on the support provided by the groove. The thrust capacity of the assembly can thus be determined by the groove specifications, including edge margin. Edge margin is the distance the groove is placed away from the end of the shaft or bore. Calculations of edge margin are generally considered in determining the thrust capacity of the assembly. Groove failure are also generally considered in determining thrust capacity of the retaining rings of the present technology, but unlike conventional retaining rings, dishing is not present thus allowing for greater capacity of the groove. Another consideration occurs when the groove material is heat treated to a hardness equal to or greater than the retaining ring. In such examples, the thrust capacity of the retaining ring can be determined and limited by ring shear since the groove will not deform with an applied force. 
     Retaining rings of the present technology are preferably utilized in assemblies where the thrust load applied by the adjacent component will be bi-directional, having both an axial portion and a radial portion. Without being bound by any particular theory, it is believed that the unique design parameters of the presently disclosed retaining rings result in increased thrust capacity under such conditions. As illustrated in  FIGS. 12A and 12B , the adjacent component  124  abutting the retaining ring  122 , which is positioned in a groove on a shaft  120 , can have an angular contact surface that contacts the retaining ring  122  at a contact point  126 . The thrust  128  of the component  124  as exerted on the retaining ring at the contact point  126  has an axial portion  128   a  and a radial portion  28   b . In another example, as illustrated in  FIG. 13 , an adjacent component  134  can have a radiused edge that makes contact with a retaining ring  132  at a contact point  138 . Retaining ring  132  is positioned in a groove on shaft  130 . In some examples, as illustrated in  FIG. 14 , where a retaining ring  142  is positioned in a groove on a shaft  140 , a direct contact between an adjacent component  144  and a retaining ring  142 , such as the type of contact typically utilized with conventional retaining rings, can occur at a contact surface  146 . Such direct contact can be suitable for some applications, although the thrust capacity of the retaining ring  142  can be reduced as compared to the maximum potential thrust capacity of the retaining ring  142 . 
       FIG. 15  illustrates an application where a retaining ring  152  is positioned in a groove on a shaft  150 . An adjacent component  154 , having a chamfered edge, contacts the retaining ring  152  at a contact point  156 , and a portion of the adjacent component  154  overlaps the retaining ring  152  by an amount  158 . Because of the low radial profile of retaining ring  152 , the adjacent component  154  can overhang the retaining ring  152 , which can assist in preventing the retaining ring from coming out of the groove for such things as vibration, shock loads, or rotational capacity. The contact angle between the retaining ring and the adjacent component can be any suitable angle to accomplish a desired amount of overlap. With conventional retaining rings, such overlap is avoided, which can result in a retaining ring coming out of its groove as a result of vibration, rotation or other external force and potentially damage the assembly. 
     Retaining rings are preferably removable, so that they can be removed in the field to allow removal of the components that they support. Retaining rings of the present technology tend to be significantly easier to install and remove from their grooves than conventional retaining rings. Without being bound by any particular theory, it is believed that because retaining rings of the present technology have a thin radial width, they tend to be pliable because they deflect with respect to the thinner dimension of the cross-section as opposed to a thicker dimension. Conventional retaining rings have a much wider radial dimension, and are thus more difficult to deflect since they deflect around that thicker dimension of the ring. 
     With respect to installing and removing retaining rings, the industry has developed tools that are used to manipulate retaining rings. In the design of some retaining rings, there are holes in the ends of each ring for use with pliers designed for retaining rings. The pliers have round tips that fit into the ring&#39;s holes that will expand or contract the ring for installation or removal. Other rings may be removed using a blunt object such as a screwdriver or dental pick.  FIGS. 16 ,  17 A and  17 B illustrate retaining rings of the present technology having features that can accommodate the use of tools in removing the rings from a groove on a shaft or within a bore. It is particularly preferred that retaining rings for use within a bore be formed with such features, to assist in ensuring easy removal by preventing the retaining ring from spinning within the groove during removal. 
       FIG. 16  illustrates a retaining ring  172  on a shaft  170 . Retaining ring  172  has removal holes  178  and  180  at the ends of the retaining ring  172 , to facilitate the removal of the ring using conventional snap ring pliers. The pliers have tips that fit into the holes and the ring may be expanded or contracted by squeezing the ring or expanding the ring. In particular, the retaining ring  172  has a radial width  174 , an axial thickness  176 , a first end  182  having a first removal hole  178 , and a second end  184  having a second removal hole  180 . 
       FIGS. 17A and 17B  show an example of a retaining ring  180  having a radial width  182  and an axial thickness  184 . At least one end of the retaining ring  180  also includes a bend  186 , to provide a small space between the ring and the groove for a screwdriver or other blunt object to enter, to pry the ring radially and remove it. The bend can be located at the first end or the second end of the retaining ring  180 . Alternatively, the retaining ring could include a bend at both the first and the second end of the retaining ring. 
     Retaining rings of the present technology can be produced from materials that are commonly used in the retaining ring industry, including but not limited to metals that can achieve spring properties, such as, for example, high carbon spring steel, full hard  302  stainless steel, beryllium copper, phosphor bronze and inconel. 
     Applications for retaining rings of the present technology are virtually unlimited. Bearings, for example, are commonly situated on a shaft and located against a retaining ring in an assembly. The retaining ring needs to be removed in the field to take the bearing off and be able to replace it. Bearings typically have a large radius on their corner that would apply a load against the retaining ring, resulting in both axial and radial loading. Conventional retaining rings provide limited thrust capacity in such applications because they are designed to accommodate only axial loads, whereas the currently disclosed retaining rings can provide increased thrust capacity because they are designed to accommodate thrust loading in both an axial and radial direction. In the case of a thin walled sleeve, it is often a limitation that the groove be kept as shallow as possible. Engineers over the years have had to design in special retaining rings that accommodate shallow grooves, but the depth of the groove needs to be at a certain dimension to handle the thrust capacity primarily as a result of the moment arm resulting from ring dishing. With the use of retaining rings of the present technology, this can be less of a concern, because the groove depth needed to accommodate the retaining ring is shallower. Still another application would be what is termed an o.d./i.d. lock system. In this design a shaft and a bore are assembled together with a retaining ring that is buried within a groove in the shaft and the bore. In typical designs, the groove on one side, either the shaft or bore, is made to normal specifications. The groove on the other component in that assembly has a groove that is at least twice the radial width of the ring to allow the ring to bury itself during assembly. With conventional retaining rings, the groove depth can thus become a serious limiting factor in the design. When utilizing a hoop retaining ring in such applications, the overall requirement for the groove depth is reduced because the normal specification for groove depth is more shallow. 
     EXAMPLES 
     Tables 1-4 below contain testing results for tests conducted on exemplary retaining rings of the present technology, as well as on comparative examples of conventional retaining rings. Tables 1 and 2 contain the test results for the exemplary retaining rings of the present technology. Tables 3 and 4 contain the test results for the comparative examples of conventional retaining rings. The columns labeled Contract Force and Expand Force of each of the tables shows the force required to expand or contract the retaining rings. As can be seen by the data, the force required to install or remove the exemplary retaining ring is substantially less than for the comparative examples. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Example Retaining Rings 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 THRUST 
                 THRUST 
               
               
                 Hoop 
                   
                   
                   
                   
                   
                   
                 LOAD BASED 
                 LOAD BASED 
               
               
                 Retaining 
                   
                 BORE 
                 WIRE 
                 COMPRESSED 
                 CONTRACT FORCE 
                 GROOVE 
                 ON RING 
                 ON GROOVE 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 Ring 
                 FREE O.D. 
                 DIA. 
                 SIZE 
                 TO 
                 sample #1 
                 sample #2 
                 DEPTH 
                 SHEAR 
                 DEFORMATION 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 .789-.804 
                 .750 
                 .024 × .088 
                 .740 
                 1.8 LBS 
                 1.8 LBS 
                 .012 
                 2147 LBS 
                 635 LBS 
               
               
                 2 
                 1.044-1.064 
                 1.00 
                 .024 × .088 
                 .990 
                  .9 LBS 
                  .9 LBS 
                 .012 
                 2863 LBS 
                 847 LBS 
               
               
                 3 
                 3.105-3.135 
                 3.00 
                 .045 × .225 
                 2.900 
                 2.5 LBS 
                 2.3 LBS 
                 .0225 
                 16108 LBS  
                 4768 LBS  
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Example Retaining Rings 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 THRUST 
                 THRUST 
               
               
                 Hoop 
                   
                   
                   
                   
                   
                   
                 LOAD BASED 
                 LOAD BASED 
               
               
                 Retaining 
                   
                 SHAFT 
                 WIRE 
                 EXPANDED 
                 EXPAND FORCE 
                 GROOVE 
                 ON RING 
                 ON GROOVE 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 Ring 
                 FREE I.D. 
                 DIA. 
                 SIZE 
                 TO 
                 sample #1 
                 sample #2 
                 DEPTH 
                 SHEAR 
                 DEFORMATION 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 4 
                 .696-.711 
                 .750 
                 .024 × .088 
                 .760 
                 5 LBS 
                 6 LBS 
                 .012 
                 2147 LBS 
                 635 LBS 
               
               
                 5 
                 .936-.956 
                 1.00 
                 .024 × .088 
                 .1010 
                 2 LBS 
                 2 LBS 
                 .012 
                 2863 LBS 
                 847 LBS 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Comparative Controls 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 THRUST 
                 THRUST  
               
               
                   
                   
                   
                   
                   
                   
                   
                 LOAD BASED 
                 LOAD BASED 
               
               
                 Circlip 
                   
                 BORE 
                 WIRE 
                 COMPRESSED 
                 CONTRACT FORCE 
                 GROOVE 
                 ON RING 
                 ON GROOVE 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 Ring 
                 FREE O.D. 
                 DIA. 
                 SIZE 
                 TO 
                 sample #1 
                 sample #2 
                 DEPTH 
                 SHEAR 
                 DEFORMATION 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 1 
                 .529-.542 
                 .500 
                 .035 × .055 
                 .490 
                 34.2 LBS 
                 34.3 LBS 
                 .012 
                 1886 LBS 
                  423 LBS 
               
               
                 2 
                 1.000-1.015 
                 .937 
                 .043 × .085 
                 .927 
                 38.7 LBS 
                 38.6 LBS 
                 .024 
                 4312 LBS 
                 1582 LBS 
               
               
                 3 
                 1.529-1.544 
                 1.437 
                 .054 × .128 
                 1.427 
                 63.9 LBS 
                 63.7 LBS 
                 .039 
                 8355 LBS 
                 3856 LBS 
               
               
                 4 
                 2.007-2.027 
                 1.875 
                 .065 × .158 
                 1.865 
                 83.5 LBS 
                 83.7 LBS 
                 .056 
                 13044 LBS  
                 7418 LBS 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 4 
               
             
            
               
                   
               
               
                 Comparative Controls 
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                   
                   
                   
                   
                   
                   
                   
                 THRUST 
                 THRUST 
               
               
                   
                   
                   
                   
                   
                   
                   
                 LOAD BASED 
                 LOAD BASED 
               
               
                 Circlip 
                   
                 SHAFT 
                 WIRE 
                 EXPANDED 
                 EXPAND FORCE 
                 GROOVE 
                 ON RING 
                 ON GROOVE 
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 Ring 
                 FREE I.D. 
                 DIA. 
                 SIZE 
                 TO 
                 sample #1 
                 sample #2 
                 DEPTH 
                 SHEAR 
                 DEFORMATION 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
               
            
               
                 5 
                 .511-.524 
                 .562 
                 .035 × .055 
                 .572 
                 23.0 LBS 
                 23 LBS 
                 .015 
                  2113 LBS 
                  565 LBS 
               
               
                 6 
                  .991-1.004 
                 1.052 
                 .043 × .085 
                 1.072 
                 30.0 LBS 
                 29 LBS 
                 .024 
                  4915 LBS 
                 1794 LBS 
               
               
                 7 
                 1.497-1.517 
                 1.625 
                 .065 × .158 
                 1.535 
                 79.0 LBS 
                 79 LBS 
                 .046 
                 11384 LBS 
                 5277 LBS 
               
               
                 8 
                 2.023-2.048 
                 2.187 
                 .072 × .200 
                 2.197 
                 76.0 LBS 
                 77 LBS 
                 .059 
                 16968 LBS 
                 9113 LBS 
               
               
                   
               
            
           
         
       
     
     From the foregoing, it will be appreciated that although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit or scope of the invention. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting, and that it be understood that it is the following claims, including all equivalents, that are intended to particularly point out and distinctly claim the subject matter regarded as the invention.