# US 2014/0152086 A1 · Undercarriage track link

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- Number: US 2014/0152086 A1
- Document ID: US20140152086A1
- Status: Published application
- Kind: A1
- Application number: 13/690,615
- Filed: 2012-11-30
- Published: 2014-06-05
- Earliest claimed: 2012-11-30
- Assignees: Caterpillar Inc.
- Applicants: Caterpillar Inc.
- Inventors: Robert Lee Meyer; Michael Dean Hasselbusch; Gergory Wayne Tomlins
- Web page: https://patentgrep.com/patent/US20140152086A1

## CPC

- B62D 55/21: Links connected by transverse pivot pins
- C21D 1/18: Hardening (C21D1/02 takes precedence); Quenching with or without subsequent tempering (quenching devices C21D1/62)
- C21D 1/22: Martempering
- C21D 9/0068: {for particular articles not mentioned below}
- C21D 9/0087: {for chains, for chain links}
- B62D 55/14: Arrangement, location, or adaptation of rollers
- C21D 2211/008: Martensite
- B62D: MOTOR VEHICLES; TRAILERS (steering, or guiding on a desired track, of agricultural machines or implements A01B69/00; wheels, castors, axles, increasing wheel adhesion B60B; vehicle tyres, tyre inflation or tyre changing B60C; connections between vehicles of a train or the like B60D; vehicles for use on rail and road, amphibious or convertible vehicles B60F; suspension arrangements B60G; heating, cooling, ventilating or other air treating devices B60H; windows, windscreens, non-fixed roofs, doors or similar devices, protective coverings for vehicles not in use B60J; propulsion plant arrangements, auxiliary drives, transmissions, controls, instrumentation or dashboards B60K; electric equipment or propulsion of electrically-propelled vehicles B60L; power supply for electrically-propelled vehicles B60M; passenger accommodation not otherwise provided for B60N; adaptations for load transportation or to carry special loads or objects B60P; arrangement of signalling or lighting devices, the mounting or supporting thereof or circuits therefor, for vehicles in general B60Q; vehicles, vehicle fittings or vehicle parts not otherwise provided for B60R; servicing, cleaning, repairing, supporting, lifting, or manoeuvring, not otherwise provided for, B60S; brake arrangements, brake control systems or parts thereof B60T; air-cushion vehicles B60V; motor-cycles, accessories therefor B62J, B62K; testing of vehicles G01M)
- C21D: MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING (surface treatment of metallic material involving at least one process provided for in class C23 and at least one process covered by this subclass C23F17/00; unidirectional solidification of eutectic materials or unidirectional demixing of eutectoid materials C30B)

## Abstract

A track link is disclosed for use with an undercarriage of a machine. The track link may have a body with a first surface and a second surface opposite the first surface. The track link may also have a shoe face extending between the first and second surfaces at a side of the body, and a roller rail extending between the first and second surfaces at a side of the body opposite the shoe face, The body may have a substantially uniform hardness of about 45 to 55 Rkw C between the shoe face and the roller rail.

## Claims

### Claim 1

A track link, comprising:
a body having a first surface and a second surface opposite the first surface;
a shoe face extending between the first and second surfaces at a side of the body; and
a roller rail extending between the first and second surfaces at a side of the body opposite the shoe face,
wherein the body has a substantially uniform hardness of about 45 to 55 Rkw C between the shoe face and the roller rail.

### Claim 2 (depends on 1)

The track link of claim 1, further including:
a first pin opening extending from the first surface to the second surface; and
a second pin opening extending from the first surface to the second surface and spaced apart along a length direction of the body.

### Claim 3 (depends on 2)

The track link of claim 2, wherein the first and second surfaces are substantially planar and parallel to one another.

### Claim 4 (depends on 3)

The track link of claim 3, wherein the track link further includes a mounting hole extending from the shoe face into the body toward the roller rail.

### Claim 5 (depends on 4)

The track link of claim 4, wherein the mounting hole is threaded.

### Claim 6 (depends on 1)

The track link of claim 1, wherein the roller rail projects away from the body at the first surface.

### Claim 7 (depends on 2)

The track link of claim 2, further including:
a first window extending from the first surface toward the second surface;
a second window extending from the first surface toward the second surface; and
a seat formed within each window.

### Claim 8 (depends on 1)

The track link of claim 1, wherein the body is made from at least one of SAE 15B35 or SAE 41B35 steel.

### Claim 9 (depends on 1)

The track link of claim 1, wherein the body is made of steel having a composition, by weight percent, of about 0.20 to 0.45% carbon, about 0.4 to 1.5% manganese, about 0.5 to 2.0% silicon, about 0,01 to 2.0% chromium, about 0.15 to 1.2% molybdenum, about 0.01 to 0,40% vanadium, about 0.01 to 0.25% titanium, about 0.005 to 0.05% aluminum, about 0.0001 to 0,010% boron, less than about 0.002% oxygen, about 0.005 to 0.017% nitrogen, and a balance of essentially iron.

### Claim 10

A process of forming a track link, comprising:
fabricating a steel form with a first surface and a second surface opposite the first side;
heating the steel form to create an austenite crystal structure throughout the steel form;
quenching the steel form to create a martensite crystal structure throughout the steel form:
tempering the steel form to create a substantially uniform hardness of 45 to 55 Rkw C throughout the steel form; and
machining the steel form after the fabricating, heating, quenching, and tempering.

### Claim 11 (depends on 10)

The process of claim 10, wherein machining includes;
cutting a shoe face into the steel form; and
cutting a roller rail into the steel form opposite the shoe face.

### Claim 12 (depends on 11)

The process of claim 11, wherein heating includes heating the steel form for approximately 30-60 minutes at approximately 750-1000° C.

### Claim 13 (depends on 11)

The process of claim 11, wherein heating includes heating the steel form in a furnace.

### Claim 14 (depends on 11)

The process of claim 11, wherein cutting of the shoe face and roller rail is performed with a cutting tool cooled by liquid nitrogen or liquid carbon dioxide.

### Claim 15 (depends on 11)

The process of claim 11, wherein machining further includes:
cutting a first pin opening from the first surface to the second surface at a first lengthwise end of the steel form; and
cutting a second pin opening from the first surface to the second surface at an opposing second lengthwise end of the steel form.

### Claim 16 (depends on 11)

The process of claim 11, wherein the steel form is fabricated from at least one of SAE 15B35 and SAE 41B35 steel.

### Claim 17 (depends on 11)

The process of claim 11, wherein tempering the steel form includes heating the steel form at a temperature of approximately 150-200° C.

### Claim 18 (depends on 17)

The process of claim 17, wherein tempering is performed for approximately 30-60 minutes.

### Claim 19 (depends on 11)

The process of claim 11, wherein the steel form has a composition, by weight percent, of about 0.20 to 0.45% carbon, about 0.4 to 1.5% manganese, about 0.5 to 2.0% silicon, about 0.01 to 2.0% chromium, about 0.15 to 1.2% molybdenum, about 0.01 to 0.40% vanadium, about 0.01 to 0.25% titanium, about 0.005 to 0.05% aluminum, about 000001 to 0.010% boron, less than about 0.002% oxygen, about 0.005 to 0.017% nitrogen, and a balance of essentially iron.

### Claim 20

An undercarriage assembly, comprising:
a track roller frame;
a plurality of track links, each track link of the plurality of track links pivotally connected to an adjacent track link of the plurality of track links via a respective pivot joint, such that the plurality of track links forms an endless chain; and
a plurality of rollers, configured to engage the plurality of track links,
wherein:
each track link of the plurality of track links includes:
a body having a first surface and a second surface opposite the first surface;
a shoe face extending between the first and second surfaces at a side of the body; and
a roller rail extending between the first and second surfaces at a side of the body opposite the shoe face;
the body has a substantially uniform hardness of about 45 to 55 Rkw C between the shoe face and the roller rail; and
the body is made of steel having a composition, by weight percent, of about 0.20 to 0.45% carbon, about 0.4 to 1.5% manganese, about 0.5 to 2.0% silicon, about 0.01 to 2.0% chromium, about 0.15 to 1.2% molybdenum, about 0.01 to 0.40% vanadium, about 0.01 to 0,25% titanium, about 0.005 to 0.05% aluminum, about 0.0001 to 0.010% boron, less than about 0.002% oxygen, about 0.005 to 0.017% nitrogen, and a balance of essentially iron.