KR820002392B1 - Cartridge type pivotal pin and bushing joint - Google Patents

Abstract

A cartridge pivot pin and bush joint has spaced, dry, self-lubricating bushings(14) between the pin(10) and a metal cylinder(12) surrounding the pin near the ends of the cylinder; dry, self-lubricating annular thrust bearings(16) mounted on the pin at the ends of the cylinder, thrust controlling annular retainer(18) fixed at the pin ends abutting the thrust bearings, & resilient seals(22) in grooves(20) in the retainers. the bushings are pref. of PTFE matrix on a cylindrical metal backing plate. The seal is pref. of polyethylene elastomer.

Description

Ammo-type pivot pin and bushing joint

1 is a partial cross-sectional plan view of one embodiment of an ammunition pivot pin and bushing joint of the present invention.

2 is an enlarged partial cross-sectional view of another embodiment of an ammunition pivot pin and bushing joint of the present invention.

3 is an enlarged cross-sectional view of one embodiment of a dry self-lubricating cylindrical bushing used in the pivot pin and bushing joints of FIGS. 1 and 2;

4 and 4 are enlarged cross-sectional views of yet another embodiment of an annular retainer used for the pivot pin and bushing joints of FIGS. 1 and 2, respectively.

FIG. 5 is an enlarged cross sectional view of an embodiment of the elastic sealing means used in the closed annular groove of the embodiment of FIGS. 4A and 4B.

6 is a fragmentary cross-sectional view of the elastic sealing means of FIG. 5 installed in the closed annular groove of the embodiment depicted in FIGS. 3 and 4b.

It relates to the content of published document 070810 filed with the US Patent Office on the order of the applicant of 1 May 1978 of the present invention.

The present invention relates to improved pivot pin and bushing joints, for example, a variety of hinge arrangements, such as the endless track chain of a caterpillar tractor, successive joints of a lifting and tilting device of a load loader and the like. It can be conveniently adopted in the field. More specifically, the present invention relates to a unique ammo cylinder type pivot pin and bushing joint that more appropriately addresses certain problems associated with prior art structures, in particular sealing, with improved performance.

Although the invention has been described herein with reference to a particular embodiment which is conveniently employed in an endless track of a tractor, it should be understood that the scope of the invention is not limited thereby. The junction of an ammobar type pivot pin and bushing according to the present invention can be employed in various forms and can be used in various hinge parts which can be recognized in view of the specification of the present invention as those skilled in the art.

The general types of pivot pin and bushing joints considered here are well known in the art and in this regard the seriousness of the problem has long been recognized and many developmental actions have been taken. This behavior is typical of patents, for example, U.S. Pat.No.2906562 (Bugman), 2911840 (Muller), 3244457 (Lose), 3336089 (Crickler), 343342 (Rixman), No. 3463560 and No. 3535,588 (Linthma), No.3574419 (Hatch), No. 3595572 (Main Applicant), No.3675936 (Hatch), No. 3680924 (Oat), No. 3731551 (Nelson), No. 3759586 (Oto), 3841718 (Linesma), 3948574 (Bairer), 3958836 (Brown), 3975028 (Satsuma Bayashi), 3985366 (Flow Jack), 4007972 (Bayer) ), 4030730 (Magic), and the like. The present invention is directed to improvements in this regard.

Today's hinge devices, especially those for heavy industry machinery used in building or highway construction, are heavy-duty or have hinged joints under extremely adverse operating conditions. Heavy loads include actuated and rotating actuations on loads on inclined surfaces, which exert various forces, including longitudinal thrust on the joint in several directions. Lubrication of these joints is complicated by extremely adverse operating conditions, including unavoidable dust, sand, rock and other abrasives, etc., which contact the bearing surfaces of the joint under varying weather and temperature conditions and under heavy loads. It is therefore inevitable that the joints should be lubricated and properly lubricated by simple, reliable, effective and economical sealing means under all working conditions. In addition, the bearing surfaces must be sealed against such rust or corrosion caused by ambient conditions as the joints must sometimes be stored for some time under adverse conditions, especially before installation in field work.

The prior art has been solved by eliminating their usefulness or effectiveness or withstanding one or more shortcomings that are problematic or expensive, as described in the foregoing patents. Some may be improperly lubricated or inadequately sealed and settle in a relatively short period of time. However, even if properly lubricated, the touch of the lubricant or the cost of repair or repair of such losses may be unsatisfactory. Undesirable mixing of lubricants and abrasives leads to wear until no lubrication is possible. Sealing to prevent loss of lubricant or injection of impurities is often ineffective because it is too complex or too expensive.

The need for lubrication passages and inlets increases manufacturing costs and design and metallography needs to be understood in consideration of the associated losses in structural strength. Otherwise preparing fluid lubricants increases the complexity of the device in manufacturing and also increases the cost of installation and periodic maintenance.

Some prior art pin-and-bushing joints are inherently noisy and feature large horsepower for satisfactory operation due to excessive friction losses. There is a need for minimal noise pollution and other needs to meet the requirements of OSHA, and the emphasis on energy conservation issues has become an important consideration in modern mechanical design. However, even if the prior art devices meet the working conditions, some are too expensive or inconvenient to install and repair, and some cannot be assembled without at least one split link. Some require constant monitoring of the lubricant. Some are also inflexible in that bearing surfaces are easily rusted by corrosion or other defects prior to installation.

Some prior art joints require a fabrication step or they are otherwise detrimental to the quality of the joint or structure. For example, some pivot pin and bushing joints employ a welding step during manufacture or installation. The heat applied is detrimental to rapid structural influences or otherwise results in losses due to detrimental or dissolution of nonmetallic closures and flowable lubricants.

It is therefore a general object of the present invention to provide an ammunition-type pivot pin and bushing joint that has been improved to narrowly and adequately address the drawbacks associated with prior art devices. Another object is to provide a junction between an ammo cylinder type pivot pin and a bushing that properly seals and self-lubricates impurities. Yet another object of the present invention is to provide a junction of a sealed pivot pin and bushing that is simple to manufacture, convenient to install and repair, and meets the requirements of the field. Another object is to provide a design for the joint of the pivot pin and bushing that can be assembled without a split link.

It is another object of the present invention to provide a joint between the pivot pin and the bushing which self-protects the bearing surface against rust, corrosion and other defects prior to use and extends its life during use. Yet another object is to provide a joint between the pivot pin and the bushing that removes the lubricant passage plug and inlet or otherwise eliminates problems associated with loss of flowable lubricant. It is also an object to provide a joint between a pivot pin and a bushing that is self-lubricating against rotational friction and end thrust friction.

Another object is to provide a device of noiseless operation and low friction loss to provide a joint between a self-lubricating pivot pin and a bushing that requires less energy during normal operation and requires less energy during the normal operation. It is to provide a joint of the pivot pin and the bushing characterized by the sealing surface of the.

Yet another object is to provide a junction between an ammobar type pivot pin and a bush that is tightly fitted to the compression force without the need for any welding or other detrimental work during manufacture, assembly or installation. Another object is to provide a large resistance to early failure under severe field conditions by providing a flexible pin-bushing junction characterized by a dry, self-lubricating method that is adequately sealed against impurities. These and other objects will be apparent from the description below. These objectives include a special implementation consisting of a cylindrical metal pin arranged in the middle of both ends of a large, coaxial hollow metal cylinder and a dry self-lubricating cylindrical bushing adjacent to both ends of the cylinder and between the pin and the cylinder and having a plurality of spaces. This is achieved by the junction of the ammo barrel pivot pin and bushing. The bushings are sufficiently preloaded to be radially compressed to reduce the set of compressibility under the working load, but under such working loads, the relative rotation or relative vibration of the pin relative to the cylinder is still limited to a minimum.

The dry self-lubricating annular thrust bearing is provided with the same center in the axial outward direction on the fin adjacent to both ends of the cylinder. The output regulating annular retainer is pre-loaded so that the thrust bearing is compressed at least against a part of the radially inner portion of the cylinder end by being fixedly compressed axially outwardly on the pin and contacting the thrust bearing (at the time of initial assembly). The retainer also had an annular groove or hole radially closed with the outer circumferential end of the thrust bearing and each end of the groove was arranged toward the end of the cylinder. An elastic closure means is arranged in the groove and acts to seal part of the end of the cylinder through the normal range of relative axial movement under the applied load.

In a detailed embodiment, the pins and cylinders are of hard steel. Retainers can also be made of hard steel, but optionally cold rolled steel, for example A1S1 1018 cold rolled steel. Bushings and thrust bearings are made of Teflon (trademark of E.I.Duponde Nemous and Compagne for plastics composed of tetrafluoroethylene polymers) and the elastic sealing means are made of elastomeric polyurethane. Self-lubricating cylindrical bushings are also metal plated on a suitable steel cylinder. The retainer is well manufactured in at least two pieces. In other words, the inner body of steel metal and the outer circumference are arranged on the circumferential surface and made of copper or bronze, which are relatively soft steel metal, and extend in the axial direction appropriately to the outer circumferential end of the hollow cylinder to form a primary seal therein. do.

Known materials of the structure do not belong to the part of the concept of the present invention and belong to the present invention depending on the use. Materials with similar or equivalent functional characteristics would be sufficient. These materials will be apparent to those skilled in the art of jointing of pivot pins and bushings in light of the present specification.

Appropriate greases, for example "two pairs" of lithium greases, are used in grooves or holes to aid in the insertion of resilient sealing means, to fill and lubricate all voids. The oil from the grease is believed to be absorbed by the polyurethane closure means of the elastomer, thereby improving its lubricity.

The inner surface, which guides and draws both ends thereof to facilitate compression and decompression assembly of the retainer on the pin, has a diameter larger than the middle part. This is easily accomplished by chamfering, rounding, or otherwise curving both ends. The other corners may be similarly rounded or chamfered to facilitate manufacturing or to conveniently design integrally or to design integrally conveniently.

Assembled ammunition seals increase shelf life by eliminating impurities, rust, corrosion or other crystals. To ensure this increased shelf life, parts made from ammunition can be clean and assembled in a clean state.

The invention will be more clearly understood by explaining the preferred embodiments and specifications in conjunction with the drawings in detail.

Dimensions are not required in the drawings and some aspects of the described implementations are explanatory in nature, in terms of graphical representations, graphical representations, and fragmentary cut views. In some instances, mechanical details that are not necessary to understand the invention or other details that are difficult to recognize are omitted or symbolically represented. Of course, it should be understood that the invention is not necessarily limited to the specific embodiments described herein, although the embodiment of FIG. 2 is best represented for carrying out the invention.

Referring to FIG. 1, the junction of the ammo barrel type pivot pin and the bushing is a pivot pin 10, a hollow metal cylinder 12 and a plurality of hollow metal cylinders 12 arranged on the pin 10 in the middle of both ends with the same longitudinal center. It consists of a dry self-lubricating cylindrical bushing 14 which forms a space and is arranged at the same center between the pin 10 and the cylinder 12. The bushing 14 is tightly sandwiched between the pin 10 and the cylinder 12 and is preloaded to be sufficiently compressed to reduce the compression set under the working load, but still the relative rotational movement of the pin 10 and the cylinder 12. However, vibrational movements are limited to a minimum. The dry self-lubricating annular thrust bearing 16 is installed on the pin 10 adjacent to both ends of the cylinder 12 in a wick, and is compressed and fitted so as not to move on the pin 10. Is subjected to a preload to be compressed at least against the radiating portion of the cylinder 12 end.

The degree of preloading of the bushing 14 and the annular thrust bearing 16 depends on various factors including such as the material, geometry, shape and amount of load of the structure. Such preload is empirically well determined for each type of use. The inner diameter of the thrust bearing 16 should be larger than the outer diameter of the pin 10 and also larger than the inner diameter of the cylinder 12. Thus, deformations are allowed to save material and make assembly easier under compression.

The annular retainer 18 has a closed annular groove or hole 20 and the elastic sealing means 22 is arranged in the hole to interrupt the cylinder 12 through a normal range of relative axial and vibrational motions under the working load. It acts to seal some. Grease is also filled in and improves the two functions of sealing and lubrication.

In FIG. 1 the joint of the pivot pin and bushing was used to connect the tractor links 24, 26 adjacent to the links 28, 30, respectively. Tractor links 24 and 26 vibrate relative to links 28 and 30 as the chain rotates around the sprockets of the tractor. In the three bushings 14 shown in FIG. 1 only two outer ones are considered necessary, but depend on the load and the geometry and the related factors.

The junction of the ammobar pivot pin and bushing in FIG. 2 is replaced by a suitable implementation in which the single annular retainer of FIG. 1 is arranged perpendicular to the metal inner body 32 and consists of two parts of a relatively soft metal outer body 33. Same as FIG. 1 except that. As will be apparent from FIG. 4B (described in the horn), the outer body 33 can extend laterally towards the cylinder 12 and form the cylinder 12 to form a primary seal against things such as dust or sand. It is suitable for contacting the surface of). The inner surface of the outer body 33 also serves as an outer wall of the sealed hole 34.

Referring to the preferred embodiment of FIG. 3, the self-lubricating cylindrical bushing 14 is comprised of a Teflon polymer inner cylinder 14a covered by a metal cylinder 14b, the outer cylinder 14b being steel or other suitable supporting metal. It becomes. As mentioned, the bushing 14 is preloaded such that the pin 10 and the cylinder 12 are sufficiently compressed to reduce the compression set under the condition that the joint is under load, but still under the load The relative rotational movement of the pin 10 relative to 12 is allowed to be limited to a minimum.

Referring to FIG. 4A, the thrust regulating annular retainer 18 comprises a hole 20 for elastic closure means. The retainer 18 may be made of steel, molded of powdered metal or otherwise made of other manufacturing methods.

Since the retainer 18 is compressed and decompressed to the pin 10 yarns, the inner corner is chamfered or rounded as indicated by a 20 ° angle and "R" on the inner diameter of FIG. 4a. This will ease compression and decompression operations, minimizing scratches and metal scratches. As is apparent from those skilled in metal forming and assembly, compression decompression problems can be minimized by the proper use of lubricants, and lubricants such as water, oil and grease can evaporate, in particular, reducing compression Use something that you don't want. In a detailed embodiment, materials are lubricated and capable of increasing the adhesion of the metal to the metal in compression and decompression, Loctite combinations (Locktype Coupling, Newington, Connecticut) are used. As shown in FIG. 4A, other corners or corners are rounded or rounded for convenience and to facilitate manufacturing.

In the two-part embodiment of FIG. 4B, the metal inner body 32 can be fabricated more easily and cheaply so that there is less chance of unfair breakage than the embodiment of FIG. 4A. The sealed hole 34 is thus formed by machining steps or shoulders on the outer circumferential surface of the inner body 32 and arranged on the circumferential surface and made of relatively soft metal so as to be compressed and depressed in place. The outer wall of the hole is formed by this. This provides additional flexibility so that the axial length of the outer ring can be easily changed compared to the axial length of the inner body. The inner corners are also chamfered or rounded to make compression and decompression easier and more convenient.

As will be apparent from FIG. 6 described later, the outer ring 33 is formed for primary sealing. However, in one embodiment of FIG. 4A, the primary seal can be designed in the same form, but at a high cost in processing. With regard to one-part structures having the same shape as the two-part design of FIG. 4B, the increased breakage problems during machining can be avoided by molding into more complex structures of suitable powder metals.

Referring to FIG. 5, the resilient sealing means consists of any suitable elastomeric material having the durability required for the type of device to be encountered. Various forms are written but a particularly convenient form for the closure means 22 is shown in FIG. 5. Obviously the sealing means must be elastic and have a durability that corresponds to severe work so that the joints will be subject to the sealing means. In the above-mentioned preferred embodiment the elastic closure means is of polyurethane of elastomer.

FIG. 6 depicts the sealing means 22 being compressed in a two-part retainer hole. A portion of the closure means 22 adjacent to the surface of the retainer is sufficiently curved to contact the end wall of the cylinder 12 for a sealing action so that the surface contacts the cylinder 12 despite normal relative lateral movement and wear. It remains sealed. Therefore, the sealing means of the elastomer are formed, which becomes an important protector when the primary sealing fails or becomes inadequate.

6 also shows more clearly how the outer ring 33 forms the aforementioned primary seal with the adjacent surface of the cylinder 12. In practice, it is desirable for the ring 33 to make substantial contact with the cylinder, thereby forming a wear fit during operation.

As mentioned above, the empty space in the hole, in particular the empty space between the primary and secondary sealing means, is filled with a suitable lubricant grease 35. Grease enhances the sealing effect by forming another obstacle in part to dust and other impurities that enter through the primary seal. Grease also plays a role in lubrication.

6 also shows the correlation with the installation position of the dry self-lubricating annular thrust bearing 16.

These thrust bearings 16 are suitably preloaded in order to minimize any loosening or loosening caused by relative movement or wear caused by maneuvering forces, even at least initially. In the preferred embodiment, the thrust bearing 16 is made of Teflon, and a KNT series self-lubricating thrust bearing sold under the trade name KAHR-LON in Burbank, Calif. These thrust bearings are in effective nonmetal washers that form self-lubricating surfaces on both sides of the bearing, which washers are made of teflon made of phenolic reinforced with high strength.

From the foregoing detailed description, it will be readily apparent to one skilled in the art that the object of the present invention may be achieved. Although only limited embodiments have been described, alternative embodiments and many other applications will be readily apparent to those skilled in the art from the foregoing description. These and other alternatives should be considered equally within the scope and spirit of the invention.

Claims (1)

An abutment portion of an ammunition type pivot pin and bushing consisting of a combination of a cylindrical pin and a large hollow metal cylinder arranged concentrically on the pin in the middle of both ends, the pins adjacent to both ends of the cylinder 12. 10) and the cylinder 12 and are preloaded to be sufficiently compressed to reduce the compression set at the working load of the joint but still have a minimum rotational motion of the pin 10 relative to the cylinder 12 at the working load. Dry self-lubricating cylindrical bushing 14 having a plurality of spaces to be limited to, and a dry self-lubricating annular thrust bearing adjacent to both ends of the cylinder 12 and having substantially the same center and installed on the pin 10. Compression not to move axially outwardly on the pin 10 with an annular groove 20 sealed radially outwardly of the outer radiating tip of the malleable thrust bearing 16 and the malleable thrust bearing 16. A thrust regulating annular retainer 18, which is pressed and contacts the thrust bearing 16 and pre-loads the thrust bearing against at least part of the radially inner portion of the end of the cylinder 12, and the relative axial direction in the state of the working load. Ammunition type pivot pin and bushing, characterized in that it consists of elastic sealing means 22 arranged in the groove 20 and acts to seal part of the end of the cylinder 12 through the normal range of motion and vibration movement. Junction.

Images