Patent Publication Number: US-2015075319-A1

Title: Timing pin module for use on an engine during service

Description:
TECHNICAL FIELD 
     The present disclosure relates generally to the timing of an engine. More specifically, the present disclosure relates to a timing pin module for use to establish top dead center in preparation for servicing an engine. 
     BACKGROUND 
     Engines are commonly known to include valves, a crankshaft, a flywheel, and an outer cover. During service and/or repair of an engine, the valves are required to be adjusted relative to an angular orientation of the crankshaft, for proper operation of the valves. This process that adjusts the valves relative to the angular orientation of the crankshaft is termed as the “timing” of the engine. While the engine is timed, the crankshaft and the flywheel are locked in a particular orientation (generally the top dead center position) so that the valves are adjusted relative to that particular orientation of the crankshaft. A timing pin module is generally used as a tool to fix the orientation of the flywheel of the engine with the block or fixed shroud which coincides with the top dead center position of the engine. The timing pin module is positioned within the outer cover and is made to pass through an aperture in the flywheel to position the flywheel which in turn positions the engine crank at top dead center. By this means, the crankshaft is positioned in the top dead center position. 
     Conventionally, the timing pin module is positioned proximal to various other components of the engine, such as an electronic control module (ECM), and/or a dipstick. Due to space limitations and lengthy size of the timing pin module, certain components must be disassembled from the engine, such as the dipstick and/or ECM, before the timing pin module is installed. This increases service time and rework for an operator servicing the engine. This results in increased service cost. 
     United States Patent, U.S. Pat. No. 5,440,947 discloses a timing pin apparatus to lock a flywheel of an engine with a bell housing of the engine. The timing pin apparatus includes a pin, a first spring means to bias the pin in a first direction, and a second spring means to bias the pin in a second direction. The first and second spring means are arranged linearly and form a lengthy arrangement. Moreover, since this mechanism is designed to stay in place and be retracted when service is complete however if this mechanism is triggered during operation of the machine, as a result, damage to the engine and this device is likely. What is needed is a timing pin apparatus to cost effectively position the flywheel with the housing of the engine, and to do so with little if any risk to the device triggering when the engine is in operation. The present disclosure provides a pin assembly that overcomes one or more of the aforementioned problems. 
     SUMMARY OF THE INVENTION 
     Various aspects of the present disclosure are directed to a timing pin module for an engine. The timing pin module includes a mount end and an engagement end and designed to mount on the engine to establish a top dead center position of a crankshaft within the engine. The engine includes a housing cover and a flywheel. The housing cover of the engine has an aperture to receive the timing pin module. The flywheel has an aperture to receive the engagement end of the timing pin module to lock the flywheel and the crankshaft in the top dead center position as the flywheel is selectively rotated within the engine. The timing pin module includes an adapter, a pin, and a resilient member. The adapter is disposed on the mount end of the timing pin module and includes a through hole. The adapter being mountable to the housing cover of the engine within the aperture of the housing cover. The pin includes a longitudinal axis, a first end disposed on the engagement end of the timing pin module, and a second end disposed on the mount end of the timing pin module. The pin being slideably disposed within the through hole of the adapter and being adapted to move between a retracted position and an extended position. The pin having a flywheel retention portion disposed on the first end of the pin. The resilient member having a first end engaged with the pin and a second end in engagement with the adapter. The first end of the pin being urged away from the adapter through the resilient member. Further, the first end of the pin engageably retains the flywheel through the aperture in the flywheel to establish the top dead center position of the crankshaft coinciding with the pin being in the extended position. Moreover, the first end of the pin being urged in slidable contact with a portion of the flywheel by the resilient member coinciding with the pin being in the retracted position in response to selective rotation of the flywheel and the flywheel and crankshaft not in the top dead center position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a partial perspective view of an engine showing a housing cover, a flywheel, and a timing pin module, the housing cover and the timing pin module in section according to the present disclosure; 
         FIG. 2  is a perspective view of the timing pin module of  FIG. 1  illustrating various components of the timing pin module; 
         FIG. 3  is an exploded view of the timing pin module of  FIG. 2  illustrating the structure and arrangement of various components of the timing pin module; 
         FIG. 4  is an enlarged sectional view of the timing pin module and surrounding portions of the engine as shown in  FIG. 1 , illustrating the timing pin module in a retracted position relative to the flywheel of the engine; and 
         FIG. 5  is an enlarged sectional view of the timing pin module and surrounding portions of the engine as shown in  FIG. 1 , illustrating the timing pin module in an extended and engaged position relative to the flywheel of the engine. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , there is shown an internal combustion engine  100  for use to power a machine or generator. The machine may embody a construction machine, a forest machine, a marine machine, a stationary machine, and/or any other similar machine. The engine  100  commonly includes a crankshaft (not shown), a flywheel  102 , and a housing cover  104 . 
     The crankshaft (not shown) and the flywheel  102  are suitably arranged with other components of the engine  100  to efficiently run the engine  100 , as is customary. The housing cover  104  is a stationary housing of the engine  100  and is adapted to generally cover and protect the flywheel  102 . However, it will be understood that the present disclosure contemplates that a portion of the posterior of the engine block which overlays the flywheel  102 , or a flange which is bolted to the engine block to overly the flywheel  102  may also be defined as the housing cover  104  to suitably receive a timing pin module  112  therein as will be further described below. More specifically, the housing cover  104  overlays the flywheel  102 , albeit gap  108  exists between a pin-facing surface  106  of the flywheel  102  and an inner portion  110  of housing cover  104  ( FIGS. 4-5 ). 
     Furthermore, the crankshaft (not shown) and the flywheel  102  may require to be specifically oriented and even locked to the housing cover  104  to ensure the engine  100  is in a top dead center position to properly initiate timing of the engine  100 . Therefore, during non-operation, a timing pin module  112  may be installed on the engine  100 , to lock the flywheel  102  and the crankshaft (not shown) in the top dead center position to initiate setting the timing of the engine  100 . More specifically, the housing cover  104  of the engine  100  includes an aperture  118 , to receive the timing pin module  112 . As best seen in  FIGS. 4-5 , the timing pin module  112  includes an adapter  202  having an external threaded portion  114  which is designed to extend into aperture  118  and thread directly with internal threaded portion  116  of housing cover  104 . The flywheel  102  of the engine  100  also includes an aperture  120 , in the pin-facing surface  106  of the flywheel  102 . The aperture  120  of the flywheel  102  is positioned so that the crankshaft (not shown) is in the top dead center position when the aperture  120  of the flywheel  102  faces the aperture  118  of the housing cover  104 . 
     The timing pin module  112  is designed to mount on the engine  100 , and to establish the top dead center position of the crankshaft (not shown) and the flywheel  102 , within the engine  100 . The timing pin module  112  may be installed in the aperture  118  of the housing cover  104 , and faces the pin-facing surface  106  of the flywheel  102 . The timing pin module  112  includes a mount end  122  and an engagement end  124 . The mount end  122  may be fixedly positioned in the aperture  118  of the housing cover  104  to mount the timing pin module  112  on to the engine  100 . The engagement end  124  is resiliently positioned against the flywheel  102  of the engine  100 . The engagement end  124  of the timing pin module  112  may be received by the aperture  120  of the flywheel  102  to lock the flywheel  102  in the top dead center position as the flywheel  102  is selectively rotated. 
     Referring to  FIG. 2 , there is shown the timing pin module  112 . The timing pin module  112  may be safely kept in a tool box, and installed the engine  100 , when required. More specifically, the timing pin module  112  is otherwise kept in the toolbox and mounted on the engine  100  to lock the flywheel  102 , during servicing of the engine  100 . The timing pin module  112  includes the adapter  202 , a pin  204 , and a resilient member  206 . The adapter  202 , the pin  204 , and the resilient member  206 , are arranged in a manner so that the pin  204  is movable between an extended position and a retracted position. 
     Referring to  FIG. 3 , there is shown the timing pin module  112  that illustrates the adapter  202 , the pin  204 , and the resilient member  206 , of the timing pin module  112 , in exploded form. The adapter  202  of the timing pin module  112 , is a cylindrical guide-member disposed on the mount end  122  of the timing pin module  112 . The adapter  202  may include a though hole  302  that slideably supports the pin  204  of the timing pin module  112 . Further, the adapter  202  is mountable to the housing cover  104  of the engine  100 , to mount the timing pin module  112  on the engine  100 , when required. In assembly, the adapter  202  may be in threaded engagement with the aperture  118  of the housing cover  104 . In this way, the timing pin module  112  may be mounted on to the engine  100 . 
     The pin  204  is slideably disposed within the through hole  302  of the adapter  202 . The pin  204  includes a first end  304 , a second end  306 , and a longitudinal axis X-X. The first end  304  of the pin  204  is disposed on the engagement end  124  of the timing pin module  112 . The second end  306  of the pin  204  is disposed on the mount end  122  of the timing pin module  112 . The pin  204  is adapted to resiliently move between the retracted position and the extended position along the longitudinal axis X-X. The pin  204  also includes a flywheel retention portion  308  along the first end  304 . The flywheel retention portion  308  locks with the aperture  120  of the flywheel  102 , in the extended position of the pin  204 . 
     The resilient member  206 , such as a spring member, is positioned to resiliently move the pin  204  between the retracted position and the extended position, along the longitudinal axis X-X. The resilient member  206  is axially aligned with the pin  204 , and is disposed along a periphery of the pin  204 . The resilient member  206  includes a first end  310  and a second end  312 . The first end  310  of the resilient member  206  is in fixed engagement with the pin  204 . The second end  312  of the resilient member  206  is in fixed engagement with the adapter  202 . It may be noted that the first end  310  of the resilient member  206  is in fixed engagement with the pin  204 , via a lock nut  314 . More specifically, the lock nut  314  may be fixedly attached to an outer perimeter of the pin  204 , while the first end  310  of the resilient member  206  is connected to the lock nut  314 . It may be contemplated that the lock nut  314  is shown as independent of the pin  204 . However, the lock nut  314  may be an integral component of the pin  204 . The specific structure and arrangement of the adapter  202 , the pin  204 , and the resilient member  206  enables the first end  304  of the pin  204  to be urged away from the adapter  202 . 
     Referring to  FIG. 4 , there is shown the timing pin module  112  mounted on the engine  100  while the pin  204  is in retracted position. The timing pin module  112  may be installed in the aperture  118  of the housing cover  104 , along the adapter  202  of the timing pin module  112 . More specifically, the adapter  202  is installed within the aperture  118  of the housing cover  104 , to mount the timing pin module  112 . When the flywheel  102  and the crankshaft (not shown) are not in the top dead center position, the pin  204  of the timing pin module  112 , is in retracted position. In the retracted position, the first end  304  of the pin  204  is urged to be in sliding contact with a portion  402  of the flywheel  102 , in response to a selective rotation of the flywheel  102 . 
     Referring to  FIG. 5 , there is shown the timing pin module  112  mounted on the engine  100 , while the pin  204  is in extended position. As noted above, the timing pin module  112  may be installed in the aperture  118  of the housing cover  104 , along the adapter  202  of the timing pin module  112 . As the flywheel  102  and the crankshaft (not shown) reach the top dead center position, the pin  204  moves to its extended position. In the extended position, the first end  304  of the pin  204  engageably retains the flywheel  102  through the aperture  120  in the flywheel  102 . More specifically, the flywheel retention portion  308  of the pin  204  retains the flywheel  102  in the top dead center position. 
     INDUSTRIAL APPLICABILITY 
     In operation, the engine  100  may routinely require service and/or repair. During service and/or repair, it may be required to lock the crankshaft (not shown) and the flywheel  102  in the top dead center position and then adjust intake and exhaust valves corresponding to the top dead center position. The timing pin module  112  is installed in the aperture  118  of the housing cover  104 , to establish the top dead center position of the crankshaft (not shown) and the flywheel  102 . It may be noted that the timing pin module  112  is otherwise safely kept in its unitary form in the tool box, when not being used. Since, the timing pin module  112  is safely kept in the tool box during normal operations of the engine  100 , the timing pin module  112  does not experience any damage that may be likely to be caused by various other components of the engine  100 . 
     The timing pin module  112  is installed along the adapter  202  of the timing pin module  112 . More specifically, the adapter  202  may be mounted in the aperture  118  of the housing cover  104 . Moreover, as the resilient member  206  is installed around the periphery of the pin  204 , the timing pin module  112  is relatively compactly packed as compared to conventional timing pin modules. This enables the timing pin module  112  to be installed in the aperture  118  of the housing cover  104 , without disassembling any other component (ECM and/or dipstick) of the engine  100 . Thereby, the service cost and effort are highly reduced. More specifically, the specific compact design of the timing pin module  112  facilitates easy and quick installation of the timing pin module  112  on to the engine  100 , thereby reducing the service cost. 
     Furthermore, as the timing pin module  112  is installed, the flywheel  102  may not be in the top dead center position. While the flywheel  102  is not in the top dead center position, the pin  204  is in retracted position. In the retracted position, the first end  304  of the pin  204  is urged to make sliding contact with the portion  402  of the flywheel  102 . This is due to the resilient push provided by the resilient member  206 . The flywheel  102  is then selectively rotated to reach the top dead center position. As the flywheel  102  reaches the top dead center position, the resilient member  206  urges the pin  204  to be in the extended position. In the extended position, the first end  304  of the pin  204  engageably retains the flywheel  102  through the aperture  120  in the flywheel  102 , to lock the flywheel  102  in the top dead center position. 
     It should be understood that the above description is intended for illustrative purposes only and is not intended to limit the scope of the present disclosure in any way. Those skilled in the art will appreciate that other aspects of the disclosure may be obtained from a study of the drawings, the disclosure, and the appended claim.