Metal build-up apparatus

Abstract

An apparatus for depositing metal by welding on a rotary machine element for rebuilding the same features a coupling to be connected with one end of the machine element for rotation therewith and having an inlet tube extending therefrom which extends axially into a central lubricant passage of the machine element upon connection thereto for supplying a coolant to the machine element. A seal on the end of the inlet tube tightly engages the inner wall of the central lubricant passage for preventing back flow of the coolant and the inlet tube is of such length that the seal is disposed between radial lubricant passages interconnecting with the central lubricant passage, whereby coolant flows therebetween and back along the outer periphery of the inlet tube. The coupling includes passages for exhausting the coolant there through to an exhaust line.

Description

BACKGROUND OF THE INVENTION

1. Field of The Invention

The present invention relates generally to apparatus for rebuilding worn machine elements by depositing and welding build-up metal thereon, and more particularly to an improved apparatus for cooling rotary machine components of such elements under deposition of build-up metal on the worn surface thereof for such re-building purposes.

2. The Prior Art

It is common practice to re-build various worn machine components by depositing hard build-up metal onto the worn surface of the machine elements preparatory to another extended period of use. Track rollers for engaging tracks may be considered as a typical example of such a machine element which may be re-built in this manner. In conventional practice for building-up metal onto the worn parts of track rollers, the track rollers are completely disassembled and the build-up metal is deposited onto the worn surface of the disassembled roller rims. However, this technique is not practical, because the temperature of the roller rim is elevated to a heat distortion level during the course of applying the build-up metal. Thus, the welding operation must be stopped after each single loop of the build-up metal is deposited onto the worn surface of the rotary machine element, and it is removed from the welding apparatus for cooling, or the welding operation of the build-up metal must be stopped by halves, such that the re-building operation may be shifted to another machine element while the first is cooling. Also, disassembling and re-assembling of the component parts of the track rollers is required according to past practice, which results in a considerable decrease of the working efficiency.

Another previously known technique for building-up such track rollers involves placing the roller approximately half-way into a water bath as it is in an assembled condition. However, by this technique, submerged arc welding may not be practical, and the welding areas are too cooled in the water bath to use a welding rod which requires preheating and gradual cooling. Also, this technique involves difficulties in the welding operation resulting from the necessity of shielding and the generation spatter and the like.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a cooling apparatus for permitting a worn rotary machine element to be built-up without disassembling the machine element, thereby greatly increasing the working efficiency of the re-building operation.

Another object of the present invention is to provide a cooling apparatus for permitting a worn rotary machine element to be built-up without threat of heat distortion of an internal structure of the machine element, such as seals and the surface of the machine element on which the build-up metal is to be deposited by welding.

Still another object of the present invention is to provide a cooling apparatus for enabling a worn rotary machine element to be automatically or semi-automatically built-up by arc welding, submerged arc welding, open, gas shield and so on, while the machine element is continuously rotated at a relatively slow speed in synchronism with the deposition of build-up metal onto the worn surface of the machine element.

Briefly, the foregoing and other objects are attained in accordance with the present invention by the provision of a cooling apparatus including a coolant supply tube extended axially into a central bore of a rotary machine element so as to define a dual-passage structure within the bore for continuously circulating liquid coolant through lubricating passages of the rotary machine component during the re-building operation thereof with deposition of metal by welding, whereby to prevent heat distortion of the machine element during the re-building operation by welding. Further, according to the present invention, the coolant supply tube is inserted into the central bore of the machine element from a port for filling the machine element with lubricant which is located at an end axle thereof and normally closed by a plug. The liquid coolant is introduced into the rotary machine element from the coolant supply tube and is exhausted through a passage defined between the exterior of the coolant supply tube and the walls of the central bore to an exhaust line.

BRIEF DESCRIPTION OF THE DRAWING

Various other objects, features and attendant advantages of the present invention will be more fully appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawing, wherein like reference characters designate like or corresponding parts throughout the several Figures, and in which:

FIG. 1 is a diagrammatic view of an apparatus for re-building machine elements in accordance with the principles of the present invention;

FIG. 2 is an enlarged partial sectional view of a rotary machine element connected to a cooling apparatus of the present invention and showing a flow of liquid coolant through the machine element;

FIG. 3 is an enlarged sectional view of a coupling and a plunger of the cooling apparatus to be connected to the rotary machine element for circulating the liquid coolant, which are shown in a separated condition; and

FIG. 4 is an enlarged sectional view of a coupling and a plunger of the cooling apparatus to be connected to the rotary machine element for circulating liquid coolant in accordance with another embodiment of the present invention, the coupling and the plunger being shown in a mating condition.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawings, which illustrate an apparatus for re-building track rollers used in bulldozers, tractors and the like as a specific example of the present invention, and more particularly to FIG. 1 thereof, there is shown a track roller generally indicated by the reference numeral 10 undergoing re-building while a liquid coolant is circulated therethrough by a cooling apparatus generally indicated by the reference numeral 30 of the present invention. The track roller 10 is rotatably supported on a welding work table, not shown, by a driving unit generally indicated by reference numeral 50 and the cooling apparatus 30 in such a manner that a spindle 51 of the driving unit 50 and a plunger 31 of the cooling apparatus 30 are axially aligned with a rotating axle 11 of the track roller 10 at both ends thereof. The track roller 10 is rotated by the driving unit 50, which includes a revolving disk 52 connected to a motor 53 by means of a reduction gear 54 and having a chucking member 55 for engaging an end surface of the track roller 10 so that the track roller 10 may be rotated with the plunger 31 associated therewith. While revolving the track roller 10, worn surfaces 12 of the track roller 10 are re-built with a deposition of hard build-up metal by application of torches 71 and 72 of a welding apparatus.

The plunger 31 for axially supporting the one end of the track roller 10 may be reciprocated within a pneumatic or hydraulic cylinder 32 supported by a frame 33, and concentric dual passages 34 and 35 shown in FIG. 2, for introducing liquid coolant or air from supply sources through an intake line 36 and a rotary joint 37 into lubricant passages within the track roller 10 and for exhausting the circulated liquid coolant through an exhaust line 38, are formed in an axial direction within the plunger 31. The plunger 31 can be axially connected to the axle 11 of the track roller 10 with an intermediary coupling 40 so that the internal passages 34 and 35 of the plunger 31 may be communicated with an axial bore 13 of the track roller 10 for circulating the liquid coolant through the lubricating passages of the track roller 10. The structure of the plunger 31, the coupling 40, and the track roller 10 through which the fluid coolant is circulated, will be hereinafter explained in greater detail.

As further shown in FIG. 2, the track roller 10 includes external rims 14 supportably carried on the axle 11 having the axially extending central bore 13 with a port 15 for filling the track roller 10 with lubricant, which is normally closed by a plug, not shown, and branch passages 16 and 17 radially extending from the central bore 13 to right and left bearings generally indicated by reference numerals 18 and 19 of the roller 10, which are preferably made of gunmetal bushings 20 and 21 and iron bushings 22 and 23, respectively, including radial openings 24 and 25 about their periphery for accomodating movement of the lubricant.

The coupling 40 for connecting the plunger 31 of the cooling apparatus 30 to the interior passage 13 of the track roller 10 is threaded at the stem portion 41 thereof to be threadably received in the port 15 of the central bore 13 of the axle 11. The coupling 40 includes an inlet tube 42 which extends axially into the central bore 13 in the axle 11 and carries a seal 43 for providing a seal between the exterior of the tube 42 and the interior of the bore 13 for preventing back flow of the liquid coolant, and also it is provided with passages 44 for exhausting the circulated liquid coolant to an external reservoir, not showh, the passages 44 being in concentric relationship with the inlet tube 42. Thus, the inlet tube 42 defines an exterior passage 45 within the central bore 13 which is concentric about the tube 42 and is connected to the passages 44 of the coupling 40, as is clearly shown in FIGS. 2 and 3. The length of the inlet tube 42 is determined so that the seal 43 of the inlet tube 42 may be positioned between the right and left lubricating branch passages 16 and 17. As shown in both embodiments illustrated in FIGS. 3 and 4, the coupling 40 includes an end surface 46 mating tightly with a plunger head 47, which may be of a funnel or conical shape depending upon the shape of the plunger head 47 with an incline of approximately 30.degree. to 330.degree..

A coolant receiving port 48 communicating with the inlet tube 42 is formed on the surface 46 of the coupling 40 at its center and a plurality of coolant exhausting ports 49 communicating with the passages 44 are formed midway along the slanted surface around the coolant receiving port 48.

At the center of the plunger head 47, a coolant supplying port 60 communicating with an inlet tube 61 disposed within the plunger 31, which can be connected to the coolant receiving port 48 of the coupling 40, is formed, and a plurality of coolant exhausting ports 62 communicating with the external passage 35 defined by the exterior of the inlet tube 61 and the interior of an outlet tube 64 are formed on the plunger head at positions corresponding to the positions of the coolant exhausting ports 49 of the coupling 40. Accordingly, the inlet line and the exhaust line for introducing the liquid coolant into the lubricating passages of the track roller are formed in the coupling and the plunger when they are connected. The plunger head 47 and the outlet tube 64 are rotatable within a cylindrical casing 65 by the provision of bearings 66 and 67 disposed on the outer periphery of the outlet tube 64.

Referring now to the operation of the apparatus in accordance with the present invention, the coupling 40 is threaded into the port 15 of the track roller 10 to have the inlet tube 42 extended axially into the central bore 13 of the axle 11 of the track roller 10 on which the build-up metal is deposited prior to the re-building operation, as shown in FIG. 2. Then, the track roller 10 is supported by the spindle 51 and the plunger 31 contacting with tne end surface 46 of the coupling 40 in axial alignment with the axle 11 of the roller 10, and high pressure liquid coolant, approximately at 7Kg/cm.sup.2 and 10l/min. is supplied from the intake line 36. The liquid coolant flows through the rotary joint 37, the inlet tube 61, the coolant supplying port 60, the coolant receiving port 48 of the coupling 40, the inlet tube 42 and is introduced into the central bore 13 of the track roller 10. Since the seal 43 of the inlet tube 42 is positioned between the right and left lubricating branch passages 16 and 17, the coolant ejected from the end of the inlet tube 42 is introduced to the left side bearing 18 through the branch passage 16, and is returned to the passage 45 defined by the exterior of the inlet tube 42 and the interior of the central bore 13 from the right side branch passage 17 through the right side bearing 19. Then, the coolant is exhausted through the passages 44, the exhausting ports 49 of the coupling 40, the exhausting port 62 of the plunger 31, and the external passage 35 of the plunger 31 to the exhaust line 38. Accordingly, the coolant continuously circulating through the lubricating passages within the track roller 10 removes heat from the surface which is undergoing a re-building operation by the welding torches 71 and 72, and the welded surface of the track roller is not heated up to a transformation point, such as to a temperature of 440.degree.C, and the temperature of the coolant within the roller 10 is maintained below 50.degree.C. Thus, the internal structures of the roller 10, such as seals 27, shown in FIG. 2, are not adversely affected by the heat. After finishing the welding operation, supply of the coolant is stopped, and compressed air is introduced into the inlet tube 42. The liquid coolant remaining within the track roller 10 is evaporated by the remaining heat of the track roller 10 and thus can be completely exhausted from the track roller 10 by the compressed air.

Referring to FIG. 4 and the embodiment illustrated therein, it can be seen that the passage 44 in this case, leading from the exterior passage 45 formed within bore 13, is a concentric passage formed about tube 42 within the stem 41 of the coupling 40, being substantially concentric with the passage 45. Further, the lines connecting the passage 44 with parts 49 are more direct in this case than in the embodiment of FIG. 3, wherein a common radial line or opening is utilized instead of the diagonal approach shown in FIG. 4.

Obviously, many other modifications and variations of the present invention are possible in light of the above teachings. For example, the rotary joint 37 may be connected directly to the plunger head 47 so as to rotate the plunger head 47 at the rotary joint 37, and also the intake line and the exhaust line may be reversed. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.

Claims

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An apparatus for depositing metal by welding on a rotary machine element for rebuilding the same, comprising:

means for supporting said rotary machine element being in axial alignment with an axle thereof and for rotating said rotary machine element as metal is deposited upon a worn surface of said rotary machine element;

a coupling coupled to a port of a central lubricant passage of said rotary machine element having an inlet tube axially extending into said central lubricant passage for providing coolant to a plurality of lubricant passages interconnected to said central lubricant passage, said coupling including a discharge passage for exhausting said coolant from said lubricant passages and provided with a conical shaped end surface;

plunger means reciprocal within a cylinder and being rotatable with said rotary machine element during a re-building operation having a head mating tightly with said end surface of said coupling for supporting said rotary machine element with said axle thereof being axially aligned with said plunger, said plunger having axially extending passages being connectable to said inlet tube of said coupling and said discharge passage of said coupling for supplying said coolant from an intake line through said inlet tube to said lubricant passages of said rotary machine element and exhausting said coolant through said discharge passage to an exhaust line; and

a welding apparatus for depositing metal on said worn surface of said rotary machine element.

2. An apparatus for depositing metal by welding on a rotary machine element according to claim 1, wherein said inlet tube of said coupling axially extending into said central lubricating passage of said rotary machine element includes a seal positioned between right and left branch lubricating passages of said rotary machine element upon being disposed within said central lubricating passage for preventing a back flow of said coolant ejected from said inlet tube.

3. An apparatus for depositing metal by welding on a rotary machine element according to claim 1, wherein said plunger is connected to an air supplying source for removing coolant remaining within said lubricant passages of said rotary machine element after the re-building operation has been completed.

4. An apparatus for depositing metal by welding on a rotary machine element for rebuilding the same as set forth in claim 1 wherein said plunger further comprises sealing means disposed within said mating head and about said axially extending passages.

5. An apparatus for circulating coolant through a plurality of interconnected lubricant passages including a main central lubricant passage of a rotary machine element under deposition of build-up metal by welding comprising:

a coupling coupled to a port of said central lubricant passage of said rotary machine element having an inlet tube axially extending into said central lubricant passage for providing said coolant to said lubricant passages connected to said central lubricant passage, said coupling having a discharge passage for exhausting said coolant from said lubricant passages and being provided with a conical-shaped end surface; and

plunger means reciprocal within a cylinder and rotatable with said rotary machine element under a re-building operation having a head mating tightly with said conical-shaped end surface of said coupling for supporting one end of said rotary machine element axially in alignment with an axle of said rotary machine element, said plunger having axially extending passages to be connected to said inlet tube of said coupling and said discharge passage of said coupling for respectively supplying said coolant from an intake line through said inlet tube to said lubricant passages of said rotary machine element and exhausting said coolant through said discharge passage to an exhaust line.

6. An apparatus for circulating coolant through a plurality of interconnected lubricant passages of a rotary machine element under deposition of build-up metal by welding according to claim 5, wherein said inlet tube axially extending into said central lubricating passage includes a seal disposed about the periphery of said inlet tube at one end thereof which is adapted to be positioned between right and left branch lubricating passages radially connecting with said central lubricant passage of said rotary machine element for preventing back flow of said coolant being ejected from said inlet tube into said central lubricant passage.

7. An apparatus for circulating coolant through a plurality of interconnected lubricant passages of a rotary machine element under deposition of build-up metal by welding according to claim 5, wherein said plunger is connected to an air-supplying source for removing coolant remaining within said lubricant passages of said rotary machine element after a re-building operation has been completed.

8. An apparatus for circulating coolant through a plurality of interconnected lubricant passages of a rotary machine element under deposition of build-up metal by welding as set forth in claim 5 wherein said plunger further comprises sealing means disposed within said mating head and about said axially extending passages.