Patent Application
20110116731
The present disclosure relates to an elastomeric bushing assembly which attaches two components together. More particularly, the present disclosure relates to an elastomeric bushing assembly that increases the overall compression of the elastomeric bushing at assembly to better resist both axial and torsional loads.
This section provides background information related to the present disclosure which is not necessarily prior art.
Automotive, truck, bus and other heavy duty applications are commonly designed using an independent front and/or an independent rear suspension system to connect the chassis of the vehicle (the unsprung portion) and the body of the vehicle (the sprung portion). The independent suspension systems normally include an upper control arm, a lower control arm and a hub or knuckle which supports the tire of the vehicle. Each control arm is attached to the frame or other structural component of the vehicle using one or more elastomeric bushing assemblies. Other applications for elastomeric bushing assemblies include, but are not limited to, torque limiting rods, stabilizer bars and other connecting points in the vehicle. The elastomeric bushing assemblies provide joint stabilizer flexibility and isolation from high dynamic load applications.
Each elastomeric bushing assembly typically consists of an outer metal tube that is pressed into a control arm or into one component of the vehicle, an elastomeric bushing disposed within the outer metal and an inner metal which extends through the elastomeric bushing. The inner metal is typically attached to a bracket on a frame or another component of the vehicle. As the vehicle travels, relative movement between the sprung portion and the unsprung portion of the vehicle is accommodated by flexing of a spring such as a coil spring, a torsion bar, an air spring or by some other resilient device. The movement of the sprung portion of the vehicle in relation to the unsprung portion of the vehicle causes rotation, pivoting and/or flexing of the elastomeric bushing assemblies at the connections for the control arms, the stabilizer bars, the torque limiting rods or the other components including elastomeric bushing assemblies.
The isolation provided by the elastomeric bushing assemblies involves complex loadings but the articulation of the elastomeric bushing assemblies is normally resolved into four directions of motion. The four directions of motion include radial motion, axial motion, torsional motion and conical motion. Typically, an elastomeric bushing is designed such that the major loading acts in the radial direction.
The continued development of elastomeric bushing assemblies is directed toward improving their load resistance capabilities while simplifying construction, reducing costs and improving the durability of the elastomeric bushing assemblies.
This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
The present disclosure provides the art with an elastomeric bushing assembly having a pair of cup-shaped outer metals which define a gap between them prior to the installation of the elastomeric bushing assembly into a suitable recess located in its respective articulated component. The elastomeric bushing is bonded to both of the outer metal cups. During the assembly of the elastomeric bushing assembly into the suitable recess, the gap between the two cups is reduced or eliminated and the two cup-shaped outer metals approach each other or contact each other. The elastomeric bushing is further compressed when the gap is reduced or eliminated. The further compression of the elastomeric bushing relieves localized elastomer stresses and builds the overall compression that resists axial, radial, torsional and conical loads.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
Example embodiments will now be described more fully with reference to the accompanying drawings.
Referring now to the drawings in which like reference numerals designate like or corresponding parts throughout the several views, there is illustrated in
Coil spring 20 supports the load for the sprung portion of the vehicle and shock absorber 22 dampens the movement of the wheel with respect to frame or supporting structure 12 as is well known in the art. A torque rod or anti-roll bar 28 can be disposed between frame or supporting structure 12 and hub or knuckle 18 to assist in the control of the wheel with respect to frame or supporting structure 12 as is well known in the art.
Referring now to
While the present disclosure is being illustrated as having two elastomeric bushing assemblies 46 disposed between upper control arm 14 and 16 and frame or supporting structure 12 and one elastomeric bushing assembly 46 disposed between lower control arm 16 and frame or supporting structure 12, it is within the scope of the present disclosure to utilize elastomeric bushing assembly 46 between any two components that require one of the components to pivot with respect to the other component. In addition, while the present disclosure is being described as having three identical elastomeric bushing assemblies 46 disposed between control arms 14 and 16 and frame or supporting structure 12, it is within the scope of the present disclosure to utilize a different design for each elastomeric bushing assembly 46. Also, while the present disclosure is being illustrated in conjunction with an independent suspension system, it is within the scope of the present disclosure to utilize elastomeric bushing assembly 46 in other suspension designs including, but not limited to, leaf spring suspension systems.
Referring now to
Inner component 60 is illustrated as a metal bar pin which includes a generally cylindrical center section 70 and a pair of generally rectangular sections 72, one generally rectangular section 72 being disposed at opposite ends of cylindrical center section 70. While inner component 60 is illustrated as a metal component, it is within the scope of the present disclosure to use other materials for inner component 60. Each generally rectangular section 72 has an aperture 74 extending through it which is used to secure elastomeric bushing assembly 46 to the appropriate bracket. While inner component 60 is illustrated as a bar pin having a generally cylindrical center section 70, it is within the scope of the present disclosure to have different inner components including, but not limited to, a cylindrical bar, a tubular bar or any other inner component known in the art. If a tubular inner component is used, typically a through bolt extending through the inner component is used to secure the elastomeric bushing assembly to the vehicle.
Elastomeric bushing 62 is an elastomeric annular member which is located between inner component 60 and outer components 64. The uncompressed wall thickness of annular elastomeric bushing 62 is larger than the space between inner component 60 and outer components 64 such that a specified percent compression is applied to elastomeric bushing 62 when it is assembled into elastomeric bushing assembly 46. The assembly of elastomeric bushing 62 is accomplished by first bonding elastomeric bushing 62 to outer components 64 and then inserting inner component 60 into elastomeric bushing 62. The compression of elastomeric bushing 62 provides the specified percent compression of elastomeric bushing 62 and inner component 60 is bonded to elastomeric bushing 62 during assembly in order to resist relative motion between the two components. While the present disclosure illustrates a bond between elastomeric bushing 62 and inner component 60, it is within the scope of the present disclosure to provide a mechanical bond due to the compression of elastomeric bushing 62 between elastomeric bushing 62 and inner component 60.
Outer components 64 are each a cup-shaped component which is illustrated as a metal cup-shaped component. While outer components 64 are illustrated as metal components, it is within the scope of the present disclosure to use other materials for outer components 64. As illustrated in
Referring now to
Referring now to
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the invention, and all such modifications are intended to be included within the scope of the invention.
