Patent Application
20160333919
The present disclosure relates to key lock inserts, and more specifically to a method and system for installing the keylock insert efficiently within a remanufactured or repaired hole.
Threaded holes (also called tapped holes) are designed for securing various components of a machine, such as a flywheel fastened to an engine crankshaft, by the use of threaded fasteners. During operations, the threaded holes may get damaged due to induced stresses and cyclic loads. The threaded holes may also be damaged due to harsh working conditions, such as rusting, or heat. As a result, the components tend to malfunction due to lack of support from the threaded fasteners, and hence cause the machine downtime. Therefore, there is a need for remanufacturing damaged holes to original specifications for reuse.
During remanufacturing, damaged threads of the damaged holes are repaired by reboring the damaged holes and using a keylock insert for reusing the damaged holes. Conventionally, the installation of the keylock insert requires special tools and skilled operators to property install the keylock insert within the tapped holes. Further, special procedures are followed for proper alignment of the keylock insert within the tapped hole.
Currently, during the installation of the keylock insert, a hammer is commonly used to make pins of the keylock insert flush within the tapped hole and lock into the threads of the tapped holes. However, hammering of the pins may damage the threads of both the tapped hole and the key lock insert. Moreover, hammering of the pins may also damage the pins and, in turn, make the keylock insert inefficient. Furthermore, hammering is cumbersome for the operator and there are chances of misalignment of the key lock insert with respect to a vertical axis of the tapped hole. As a result, the conventional techniques suffer from inefficiency, lack of reliability and involve additional rework.
Therefore, there is a need for a method and system for installing the keylock insert within the tapped hole.
In one aspect of the present disclosure, a method for installing a keylock insert into a tapped hole of a structure is disclosed. The keylock insert having a first end, a second end, internal threads, external threads, and a plurality of pins extending away from the first surface along an axis of the keylock insert. The method comprises positioning the second end of the keylock insert parallel to a mounting surface of the structure and the axis of the keylock insert being oriented along an axis of the tapped hole. The method further comprises fastening the key lock insert into the tapped hole, such that threads of the tapped hole being mated with the external threads of the keylock insert, and securing the keylock insert within the tapped hole by a fastening system, the fastening system deforming and compressing the plurality pins of the keylock insert between the tapped hole and the external threads of the keylock insert.
In another aspect of the present disclosure, a fastening system for installing a keylock insert into a tapped hole is disclosed. The system includes a bolt having a head portion and a cylindrical portion, the cylindrical portion having threads extending thereon, a thrust bearing having a first race and a second race, the thrust bearing having an inner surface and an outer surface, the inner surface having a hollow cavity for receiving the bolt, and at least one washer coupled to the thrust bearing via the second race. Then at least one washer is configured to apply a uniform thrust to compress a plurality of pins of the keylock insert into the tapped hole and protect the bearing from damage. Further locking the plurality of pins between threads of the lapped hole and external threads of the keylock insert in a manner that the keylock insert being permanently fixed in a way that an axis of the keylock insert overlaps with an axis of the lapped hole.
Other features and aspects of this disclosure will be apparent from the following description and the accompanying drawings.
Referring to
The tapped holes 12 are provided to receive a keylock insert 18. The key lock insert 18 having external threads 20, internal threads 22, a first hollow cavity 24, a first end 26, a second end 28, a number of keys 30 (also called pins 30), a number of grooves 32 extending from the first end 26 till the second end 28. The keylock insert 18 is used to repair damaged or worn out threads by inserting the keylock insert 18 in the damaged thread. The grooves 32 are provided to receive the keys 30 in an axial direction ‘D’. Further, the keylock insert 18 may include chamfers (not shown) on the second end 28 to aid in fitment. During assembly, the external threads 20 of the keylock insert 18 are mated with the threads 16 of the tapped holes 12. As an example, the keylock insert 18 may be manually tightened inside the lapped hole 12 until the first end 26 is parallel and coplanar with the mounting surface 14 of the component 10. During fastening of the keylock insert 18, the keylock insert 18 is positioned within the tapped holes 12 in a manner that the second end 28 of the keylock insert 18 is parallel to the mounting surface 14 of the structure 10 and the axis X-X′ of the keylock insert 18 being oriented along axis Y-Y′ of the tapped holes 12.
Referring to
The washer 42 includes a fourth surface 62, a fifth surface 64, and a third hollow cavity 66 (also refer to
Referring to
Currently, hammering is a challenge for a machinist for inserting the keys 30 of the keylock insert 18. Uniform and gradual insertion of the keys 30 using the fastening system 34 reduces the risk of damage to the keys 30, the threads 16 and the external threads 20 of the keylock insert 18.
The washer 42 assisted by the thrust bearing 40 provides a uniform axial load on the keys 30, and hence mitigates the risks of damage to the threads 16 and the external threads 20. The machinist may hand screw the keylock insert 18 into the tapped holes 12 and tighten the keylock insert 18 in a single go in order to save assembly time and without requiring any specially trained personnel. The fastening system 34 may be easily manufactured with a low cost.
While aspects of the present disclosure have been particularly shown and described with reference to the embodiments above, it will be understood by those skilled in the art that various additional embodiments may be contemplated by the modification of the disclosed machines, systems and methods without departing from the spirit and scope of what is disclosed. Such embodiments should be understood to fall within the scope of the present disclosure as determined based upon the claims and any equivalents thereof.
