Patent Application
20160084323
The present invention relates generally to a dampening device for clutch assemblies and specifically to an elastomeric or fluid/viscous damper for reducing or eliminating torsional and bending vibration frequencies during clutch engagement and disengagement.
Automobile transmission systems, specifically automatic transmission systems, include gear elements, such as planetary gears, and selectively engageable friction elements or clutches that are controlled to establish one of several forward speed ratios between the transmission input and output shafts. The input shaft is typically coupled to the vehicle engine through a fluid coupling such as a torque converter, and the output shaft is coupled to the vehicle drive wheels through a differential gear set.
Shifting from a currently established speed ratio to a new speed ratio involves, in most cases, disengaging a clutch associated with the current speed ratio and engaging a clutch associated with the new speed ratio. Engagement and disengagement of a clutch may result in unwanted noise and vibration, such as vibrations caused by contact between the transmission hub and one or more plate components, such as discs or steel pairs.
Therefore, an improvement in the art is needed to address this problem.
A clutch damper is generally provided to dampen unwanted noise and vibration within a clutch assembly. The clutch damper may be connected to a hub located on a shaft within the clutch assembly.
In an embodiment, the clutch damper includes an inertia member and an elastomeric member positioned about the inertia member. The elastomeric member may be connected to an inner wall of a hub, or optionally a mounting ring may be positioned between the elastomeric member and the hub to facilitate mounting to the hub. The mass of the inertia member and thickness and stiffness of the elastomeric member may be tuned to dampen objectionable or unwanted vibration frequencies within the clutch assembly.
In an embodiment, the clutch damper includes a housing comprising a hollow annular ring having a cavity therein. An inertia member is positioned within the cavity along with a viscous fluid. The mass of the inertia member, viscosity of the fluid, and fluid pressure within the cavity may be tuned to dampen objectionable or unwanted vibration frequencies within the clutch assembly.
Operation of the invention may be better understood by reference to the following detailed description taken in connection with the following illustrations, wherein:
While the invention is described herein with reference to several embodiments, it should be clear that the invention should not be limited only to the embodiments disclosed or discussed. The description of the embodiments herein is illustrative of the invention and should not limit the scope of the invention as described or claimed.
The hub 12 may be any appropriate size and shape, such as generally cylindrical, as shown in
The clutch assembly 10 may include a plurality of plates 28, such as friction plates. The plates 28 may be configured to engage the outer surface 22 hub 12 and rotate therewith. For example, the plates 28 may include teeth arranged to engage the gears 26 of the hub 12. The plates 26 may selectively engage an outer housing based on the selected gearing ratio. For example, the clutch assembly 10 may compress the plates 28, using fluid pressure or otherwise, to engage the plates 28 with the outer housing 18 to move in unison with the hub 12.
In operation, the engagement between the plates 28 and the outer housing that occurs when the transmission changes gears may cause unwanted noise and vibrations on the hub 12. For example, the plates 28 may include outer teeth or gears that may engage openings in the outer housing and may cause unwanted ringing or vibration. The hub 12 may therefore be equipped with a damper to reduce the unwanted ringing and vibration.
In an embodiment, the damper 30 may include a mounting ring 32, as shown in
The damper 30 includes an inertia member, such as an inertia member 34. The inertia member 34 may be generally circular or cylindrically shaped, and sized to fit within at least a portion of the mounting ring 32. For example, the inertia member 34 may have an L-shaped cross-section, as shown in
The damper 30 may include an elastomeric member 40. The elastomeric member 40 may be annular shaped and formed out of any appropriate elastomeric material, such as rubber. The elastomeric member may be positioned between the inertia member 34 and the mounting ring 32. For example, the elastomeric member 40 may be positioned between the inner ring 36 and the inside of the mounting ring 32 in a concentric arrangement, allowing the inner ring 36 to protrude through an opening in the annular elastomeric member 40
While the damper 30 is shown and described as including the mounting ring 32, it will be appreciated that the damper 30 may be connected directly to the hub 12 without use of a mounting ring 32. For example, the elastomeric member 40 may be directly connected to the inner surface 24 of the hub 12.
The damper 30 may be tuned to absorb and reduce the system's resonant vibrations. Specifically the mass of the inertia member 34 and thickness and stiffness of the elastomeric member 40 may be tuned to dampen the resonant noise and vibrations caused by the contact between the hub 12 and the outer housing. The damper 30 may be tuned to dampen both torsional and bending frequencies. The inertia member 34 may provide the inertia necessary to control the vibration and the elastomeric member 40 may provide the desired stiffness to dampen the resonant frequencies by converting the vibration energy to heat.
The damper 30 may include a plurality of openings to allow lubrication to enter and flow through the system. The openings may be any appropriate shape and size and may be arranged to allow oil or any lubricant to flow through and around the damper to various components of the clutch assembly 10.
In an embodiment, the inertia ring 34 and elastomeric member 40 may be configured in a stacked arrangement, as shown in
In an embodiment, a mounting ring 32 may be positioned between the elastomeric member 40 and the face 16 of the hub 12. The mounting ring 32 may be connected directly to the inside of the face 16. As shown in
In an embodiment, the clutch assembly 10 may include a viscous damper 50. The viscous damper 50 may be configured to engage the hub 12 and dampen unwanted vibrations using friction and viscosity.
The viscous damper 50 may include a housing 52. The housing 52 may be generally circular or annular to form a hollow ring having a cavity 54 inside. The housing 52 may be sized and shaped to fit within and connect to the hub 12. For example, the housing may connect to the inner surface 24 of the hub 12. Alternatively, the inner surface 24 may form a portion of the housing 52. One surface of the housing 52 may comprise a cover 56. The cover 56 may be removable to provide access to the cavity 54, and may be fixed to the housing 52 by any appropriate means, such as laser welded to the housing. The cover 56 may comprise a generally flat ring configured to connect to the inner surface 24 of the hub 12.
An inertia ring 58 may be located within the cavity 54. The inertia ring 58 may be generally annular and sized and shaped to fit within the cavity with a specified clearance. The clearance or remaining area within the cavity may be filled with a viscous fluid 60, such as silicon or any appropriate viscous fluid. The fluid 60 may be input into the cavity 54 or drained from the cavity 54 through a port 62. The port 62 may be accessible via plug 64, such as a weld plug, that may be inserted into the port 62 once the fluid 60 has been into the cavity.
The viscous damper 50 may be tuned to absorb and reduce torsional frequencies on the hub 12. For example, the mass of the inertia ring 58, thickness or viscosity of the fluid 60, and clearance within the cavity 54 may be adjusted and tuned to dampen resonant frequencies within the system.
The inertia ring 58 may provide the inertia necessary to control the vibration within the clutch assembly 10, while the fluid 60 may dampen the resonant frequencies by converting the vibration energy to heat. The inertia ring 58 may move within the cavity 54 with respect to the fluid 60, thereby creating a friction or shearing force to convert the vibrations to heat.
The invention has been described above and modifications and alterations will occur to others upon a reading and understanding of this specification. The claims as follows are intended to include all modifications and alterations insofar as they come within the scope of the claims or the equivalent thereof.
