Patent Publication Number: US-2018043422-A1

Title: Frame assembly and method for mounting a rear main seal to a crankshaft of a porsche

Description:
BACKGROUND 
     The following background information may present examples of specific aspects of the prior art (e.g., without limitation, approaches, facts, or common wisdom) that, while expected to be helpful to further educate the reader as to additional aspects of the prior art, is not to be construed as limiting the present invention, or any embodiments thereof, to anything stated or implied therein or inferred thereupon 
     The following is an example of a specific aspect in the prior art that, while expected to be helpful to further educate the reader as to additional aspects of the prior art, is not to be construed as limiting the present invention, or any embodiments thereof, to anything stated or implied therein or inferred thereupon. 
     The present invention is directed to frame assembly and method for mounting a rear main crankshaft seal to a rear region of a crankshaft for a Porsche™. 
     The inventor is a Porsche™ enthusiast that enjoyed both driving and working on Porsches, and specifically the Porsche Boxter 996™ made in the years of 1997-2010 and the Porsche Carrera 911™ made in the years 2005-2010. 
     The inventor was aware that one of the most problematic aspects of the Porsche™ was the rear main crankshaft seal. This seal is used to prevent oil from leaking at the rear region of the crankshaft. The inventor knew that, in the case of a smaller, high viscosity vehicle with a manual transmission, such as the Porsche™, a faulty or worn rear main crankshaft seal can allow oil to leak onto the clutch, causing slipping and chattering. 
     Through experimentation, the inventor understood that the rear main crankshafts seal offers proven sealing ability, excellent heat resistance and easy installation. The seals were fabricated primarily from molded synthetic rubber. 
     Unfortunately, the inventor knew that after a duration of 70,000 miles, heat and pressure work to deform, oxidizes, or completely deteriorate this rubber material. This was especially problematic in a high performance sports vehicle, such as a Porsche™. Thus, the inventor attempted to invent a frame assembly that is effective for maintaining the annular shape of the seal, and lubricating the seal. 
     The inventor recognized a problem in that the elastomer properties of the seal were susceptible to high temperatures. The inventor decided to encase the seal in a metal cylinder. 
     Through additional research, the inventor learned that the seal rested in a groove at the rear region of the crankshaft, generally around a pilot shaft bearing. The inventor decided to add a flange to one end of the cylinder that would catch onto the edge of the groove, so as to create a more secure housing of the cylinder. 
     However, the cylinder and the seal contained within vibrated excessively. So the inventor decided to add two brackets that would fasten the edges of the cylinder to the crankshaft. The brackets were disposed opposite of each other and screwed into mounting holes in the crankshaft. 
     The inventor realized that the life expectancy of the seal was short, even with the protective metal cylinder. The inventor decide to coat the inner surface of the cylinder with a lubricant that would transfer to the seal. This would protect against heat hardening and oxidation of the elastomer material of the seal 
     For the foregoing reasons, there is a frame assembly and method for mounting a rear main crankshaft seal to a rear region of a crankshaft for a Porsche™. The assembly provides an annular cylinder that firmly encircles a Porsche™ rear main crankshaft seal. The cylinder and the retained seal are configured to press into a crankshaft groove that forms at the rear region of the crankshaft. The cylinder maintains the seal in an annular shape, even after a long duration of use. The cylinder comprises a lubricant that coats the seal. Two brackets fasten the cylinder and the retained seal in a crankshaft groove at the crankshaft. 
     Oil seal and gasket fitting system and methods have been utilized in the past; yet none with the characteristics of the present invention. See U.S. Pat. Nos. 3,755,875, 5,588,656; and 6,543,113. 
     For the foregoing reasons, there is a frame assembly and method for mounting a Porsche™ rear main crankshaft seal to a rear region of a crankshaft for a Porsche™. 
     SUMMARY 
     The present invention describes a frame assembly and method for mounting a rear main crankshaft seal to a crankshaft of a Porsche™. The frame assembly provides a rigid, annular cylinder that firmly encircles a rear main crankshaft seal. The cylinder and the retained seal are configured to press into a crankshaft groove that forms at the rear region of the crankshaft. In this manner, the seal the assembly forms a protective frame around the seal that extends the life of the seal. 
     The frame assembly provides at least one bracket that mounts the cylinder and the retained seal in a crankshaft groove that forms at a rear region of a crankshaft. The annular shape of the cylinder prevents deformation of the seal, even after an extended duration of use. The cylinder may also be coated with a lubricant to help prevent heat hardening and oxidation of the substantially elastomeric seal. 
     In one embodiment, a frame assembly for mounting a Porsche rear main crankshaft seal comprises a generally annular cylinder. The cylinder is defined by a first end and a second end. The second end comprises a flange. The cylinder is further defined by an outer surface having an outer diameter, and an inner surface having an inner diameter. The inner diameter is generally smaller than the outer diameter. The inner surface of the cylinder is configured to engage the rear main crankshaft seal, whereby the seal is disposed proximal to the first end of the cylinder. A snug fit between the inner surface of the cylinder and the seal helps retain the seal in the cylinder, and in conformance with the annular shape of the cylinder. 
     In some embodiments, the assembly further comprises at least one bracket configured to enable mounting of the cylinder and the retained seal to a rear region of a crankshaft for a Porsche™. The at least one bracket is defined by a first panel and a second panel disposed perpendicularly to each other. The first panel joins with the flange of the second end of the cylinder. The second panel may include an aperture. At least one fastener is configured to pass through the aperture of the second panel to fasten the cylinder and the retained seal in the rear region of the crankshaft. 
     In another aspect, the inner diameter of the cylinder is about 90 millimeters. 
     In another aspect, the outer diameter of the cylinder is about 110 millimeters. 
     In another aspect, the first panel of the at least one bracket has a generally L-shape. 
     In another aspect, the at least one bracket comprises two brackets. 
     In another aspect, the at least one fastener comprises two fasteners. 
     In another aspect, the at least one fastener comprises a threaded bolt. 
     In another aspect, the at least one fastener is configured to fasten the at least one bracket and the cylinder to a rear region of a crankshaft. 
     In another aspect, the assembly is configured to enable mounting of a rear main crankshaft seal for a Porsche™. 
     In another aspect, the cylinder is shaped and sized to snugly fit inside a crankshaft groove in a rear region of a crankshaft for the Porsche™. 
     In another aspect, the inner surface of the cylinder is configured to engage the rear main crankshaft seal, whereby the rear main crankshaft seal is disposed proximal to the first end of the cylinder. 
     In another aspect, the inner surface of the cylinder comprises a lubricant. 
     In another aspect, the cylinder is configured to mount the rear main crankshaft seal in a crankshaft groove. 
     In another aspect, the Porsche™ includes at least one member selected from the group consisting of: a Porsche Boxter 996™ made in the years of 1997-2010 or a Porsche Carrera 91™ made in the years 2005-2010. 
     In another aspect, the material of the rear main crankshaft seal includes at least one member selected from the group consisting of: polyacrylate, nitrile rubber, silicone, polytetrafluoethylene rubber, and molded synthetic rubber. 
     In another aspect, the assembly is an aftermarket component. 
     In one aspect, a method for mounting a rear main crankshaft seal to a rear region of a crankshaft for a Porsche™, comprises:
         removing a flywheel from a rear region of a crankshaft;   disengaging an expired rear main crankshaft seal from a crankshaft groove;   providing a frame assembly having a generally annular cylinder and at least one bracket;   lubricating an inner surface of the cylinder;   positioning a new rear main crankshaft seal in the inner surface of the cylinder,   whereby the new rear main crankshaft seal substantially maintains the annular shape of the cylinder;   mounting the cylinder and the retained new rear main crankshaft seal in the crankshaft groove; and   fastening the at least one bracket to the rear region of the crankshaft.       

     One objective of the present invention is to mount a rear main crankshaft seal in a rear region of a Porsche™ crankshaft; and especially when the seal expires after 70,000 miles. 
     Another objective of the present invention is to prevent the seal from deforming to an oval shape by retaining the seal in the annular shape of the cylinder. 
     Another objective of the present invention is to lubricate the seal. 
     Yet another objective of the present invention is to provide at least one bracket for securely fastening the cylinder and the seal that is retained in the cylinder to the rear region of the crankshaft. 
     Yet another objective is to provide an inexpensive assembly for replacing and mounting a seal in the rear region of the crankshaft of the Porsche Boxter 996™ made in the years of 1997-2010 and the Porsche Carrera 911™ made in the years 2005-2010. 
    
    
     
       DRAWINGS 
       These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and drawings where: 
         FIG. 1  is a perspective view of an exemplary frame assembly for mounting a rear main crankshaft seal to a rear region of a crankshaft for a Porsche™; 
         FIG. 2  is a sectioned view of an exemplary frame assembly for mounting a rear main crankshaft seal to a rear region of a crankshaft for a Porsche™; 
         FIG. 3  is a perspective view of the frame assembly shown in  FIG. 1  being positioned proximally to a crankshaft groove for mounting; 
         FIG. 4  is a sectioned view of the frame assembly shown in  FIG. 1  mounted into the crankshaft groove at the rear region of the crankshaft; 
         FIG. 5  is a perspective view of the frame assembly shown in  FIG. 1  mounted into the crankshaft groove at the rear region of the crankshaft; and 
         FIG. 6  is a flowchart diagram of an exemplary method for mounting a rear main crankshaft seal to a rear region of a crankshaft for a Porsche™. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention, referenced in  FIGS. 1-6 , is directed to a frame assembly  100  and method  200  for mounting a rear main crankshaft seal  200  to a crankshaft  202  of a Porsche™. As  FIG. 1  references, the assembly  100  and method  200  provide an annular cylinder  102  that snugly encircles and at least partially encases a rear main crankshaft seal  200  used in a Porsche™. The cylinder  102  and the retained seal  200  are configured to press into a crankshaft groove  204  that forms at the rear region of the crankshaft  202 . At least one bracket  114   a ,  114   b  fastens the cylinder  102  and the retained seal  200  to the rear region of the crankshaft  202 . In this manner, the assembly  100  forms a protective frame around the seal  200  that extends the life of the seal  200 . 
     The frame assembly  100  is designed for a specific few types of Porsches™, including: the Porsche Boxter 996™ made in the years of 1997-2010 and the Porsche Carrera 911™ made in the years 2005-2010. 
     The frame assembly  100  and method  200  provide numerous advantageous to replacing and mounting the rear main crankshaft seal  200  in the Porsche™ crankshaft. Firstly, the seal  200  is forced to conform to the annular shape of the cylinder  102 , which prevents the seal  200  from deforming to an oval shape, even after the seal  200  has been used for over 70,000 miles.  FIG. 2  shows the seal  200  conforming to the shape of the cylinder  102 . Yet another advantage provided by the frame assembly  100  and method  200  is that an inner surface  112  of the cylinder  102  may contain, or be coated with a layer of a lubricant that transfers to the seal  200 . The lubricant helps prevent heat hardening and oxidation of the substantially elastomeric seal  200 . 
     Those skilled in the art will recognize that rear main crankshaft seals prevent oil from leaking at the rear region of the crankshaft. In the case of a smaller, high viscosity vehicle with a manual transmission, i.e., Porsche™, a faulty or worn rear main crankshaft seal can allow oil to leak onto the clutch, causing slipping and chattering. The rear main crankshafts seals offers proven sealing ability, excellent heat resistance and easy installation. Molded synthetic rubber is the material most commonly used for the rear main crankshaft seal. However, after a duration of 70,000 miles, heat and pressure work to deform, oxidizes, or completely deteriorate this rubber material. This can be especially problematic in a high performance sports vehicle, such as a Porsche™. Thus, the frame assembly  100  is effective for maintaining the annular shape of the seal  200 , and lubricating the seal  200  while the seal  200  is snugly retained within the inner surface  112  of the cylinder  102 . 
     Looking now at  FIG. 3 , the frame assembly  100  comprises a generally annular cylinder  102  that is shaped and sized to snugly fit inside a crankshaft groove  204  in a rear region of a crankshaft for a Porsche™. The cylinder  102  has a depth of a few inches and an outer surface  110  that snugly engages an inner perimeter area of the crankshaft groove  204 . In some embodiments, the cylinder  102  may be fabricated substantially from a metal alloy that can withstand high temperatures, which are experienced in crankshafts, and provide protection for the seal  200 . 
     Looking back at  FIG. 1 , the cylinder  102  is defined by a first end  104  and a second end  106 . The ends  104 ,  106  form the opposite edges of the cylinder  102 . The first end  104  terminates at a generally flat edge. The second end  106  terminates at a flange  108  that extends outwardly, towards the outer surface  110  of the cylinder  102 . When the cylinder  102  is positioned in the crankshaft groove  204  at the rear region of the crankshaft  202 , the flange  108  engages the perimeter area of the crankshaft groove  204 . 
     The cylinder  102  is further defined by an outer surface  110  having an outer diameter, and an inner surface  112  having an inner diameter. The inner surface  112  of the cylinder  102  is configured to engage the rear main crankshaft seal  200 . In one embodiment, the seal  200  is positioned more proximally to the first end  104  of the cylinder  102  than the second end  106 . A snug fit between the inner surface  112  of the cylinder  102  and the seal  200  helps retain the seal  200  in the cylinder  102 , and in conformance with the annular shape of the cylinder  102 . 
     The inner diameter of the cylinder  102  is generally smaller than the outer diameter. In one embodiment, the inner diameter of the cylinder  102  is about 90 millimeters. The outer diameter of the cylinder  102  is about 110 millimeters. In one embodiment, the inner surface  112  comprises a lubricant. When the seal  200  is pressed into the inner surface  112 , the lubricant coats the seal  200  to protect the elastomer material against heat hardening and oxidation. 
     As  FIG. 4  illustrates, the assembly  100  further comprises at least one bracket  114   a ,  114   b  configured to enable mounting of the cylinder  102  and the retained seal  200  to a rear region of a crankshaft for the Porsche™. The rear region  202  where the seal  200  mounts is generally around the pilot shaft bearing of the crankshaft. In one embodiment, two bracket  114   a ,  114   bs  are used for mounting the cylinder  102  to the crankshaft. 
     The at least one bracket  114   a ,  114   b  is defined by a first panel  116   a ,  116   b  and a second panel  118   a ,  118   b  disposed perpendicularly to each other. The first panel  116   a ,  116   b  has a generally L-shape. The first panel  116   a ,  116   b  joins with the flange  108  of the second end  106  of the cylinder  102 . In one embodiment, the first panel  116   a ,  116   b  and the flange  108  are fixedly joined. In other embodiments, the first panel  116   a ,  116   b  and the flange  108  are detachably attached, through screws, magnets, or welds. 
     The second panel  118   a ,  118   b  may include an aperture. At least one fastener  120   a ,  120   b  is configured to pass through the aperture of the second panel  118   a ,  118   b  to fasten the cylinder  102  and the retained seal  200  in the rear region of the crankshaft  202 . In one embodiment, the brackets  114   a ,  114   b  are disposed at opposite areas of the cylinder  102  and screwed directly into mounting holes in the crankshaft. 
       FIG. 5  illustrates the cylinder  102  and the retained seal  200  fastened to the rear region of the crankshaft  202 . The first end  104  of the cylinder  102  engages the back of the crankshaft groove  204 . The second end  106  of the cylinder  102  terminates at the flange  108 , which overhangs the perimeter area of the crankshaft groove  204 . 
     In one embodiment, the at least one fastener  120   a ,  120   b  comprises two fasteners  120   a ,  120   b  configured to pass through each aperture in two brackets  114   a ,  114   b . The fastener  120   a ,  120   b  may include, without limitation, a screw, a threaded bolt, a weld, a magnet, and a wire. 
       FIG. 6  illustrates a flowchart diagram of an exemplary method  200  for mounting a rear main crankshaft seal to a crankshaft of a Porsche™. The method  200  may include an initial Step  202  of removing a flywheel from a rear region of a crankshaft  202 . The rear main crankshaft seal  200  is located behind the flywheel, which requires the flywheel to be removed to change the seal  200 . Generally, a flywheel lock is used to remove bolts that hold down the flywheel. 
     The method  200  may further comprise a Step  204  of disengaging an expired rear main crankshaft seal from a crankshaft groove  204 . A Step  206  includes providing a frame assembly  100  having a generally annular cylinder  102  and at least one bracket  114   a ,  114   b . The frame assembly  100  mounts a rear main crankshaft seal  200  to a rear region of a crankshaft  202  for a Porsche™. 
     In some embodiments, a Step  208  comprises lubricating an inner surface  112  of the cylinder  102 . The lubricant may include an oil or other synthetic lubricant that extends the life of the seal  202 . A Step  210  includes positioning a new rear main crankshaft seal  200  in the inner surface  112  of the cylinder  102 , whereby the new rear main crankshaft seal  200  substantially maintains the annular shape of the cylinder  102 . A snug fit between the inner surface  112  of the cylinder  102  and the new seal helps retain the new seal in the cylinder  102 , and in conformance with the annular shape of the cylinder  102 . 
     In some embodiments, a Step  212  may include mounting the cylinder  102  and the retained new rear main crankshaft seal  200  in the crankshaft groove  204 . The second end  106  terminates at a flange  108  that extends outwardly, towards the outer surface  110  of the cylinder  102 . When the cylinder  102  is positioned in the crankshaft groove  204  at the rear region of the crankshaft  202 , the flange  108  engages the perimeter area of the crankshaft groove  204 . 
     A final Step  214  includes fastening the at least one bracket  114   a ,  114   b  to the rear region of the crankshaft. The bracket  114   a ,  114   b  enables mounting of the cylinder  102  and the retained seal  200  to a rear region of a crankshaft  202  for the Porsche™. The rear region  202  where the seal  200  mounts generally surrounds the pilot shaft bearing of the crankshaft. The brackets  114   a ,  114   b  are disposed at opposite areas of the cylinder  102  and screwed directly into mounting holes in the crankshaft. 
     While the inventor&#39;s above description contains many specificities, these should not be construed as limitations on the scope, but rather as an exemplification of several preferred embodiments thereof. Many other variations are possible. For example, the frame assembly  100  may be adapted for securing main crankshaft seals for different models of vehicles. Accordingly, the scope should be determined not by the embodiments illustrated, but by the appended claims and their legal equivalents.