Track chassis roller assembly

Abstract

A track chassis roller assembly (17) includes a roller body (18) having an inner cavity (19) extending axially from a first access opening (18a) to a second access opening (18b); a shaft (22) inserted into the inner cavity (19) of the roller body (18) and extending axially from the first end portion (22a) to the second end portion (22b); a first end support (24) attached to a first end portion (22a) of the shaft (22) at a first access opening (18a); a second end support (26) attached to a second end of the shaft (22) at a second access opening (18b); a first rotating lip seal (35) attached to the roller body (18) at a first access opening (18a) and comprising a main sealing lip (43) slidably abutting on said first support (24); a second rotating lip seal (36) attached to the roller body (18) at a second access opening (18b) and comprising a main sealing lip (49) slidably abutting on said second support (26); and at least a first solid oil bearing (31) located in the inner cavity (19) and comprising a radially inner slewing ring (31a) coupled to the shaft (22) and a radially outer slewing ring (31b) coupled to the roller body (18).

Description

Technical Field

[0001] This invention relates to a tracked chassis roller assembly. Background Technology

[0002] Tracked chassis are typically used to operate machines such as earthmoving machines, mining machines, crushing machines, combine harvesters, etc., to allow the machines to move on surfaces that are often uneven or have poor traction.

[0003] Tracked chassis typically include two chain assemblies spaced apart and arranged parallel to each other, configured to receive drive torque and transmit it to the ground. Each chain assembly includes multiple chassis components, which typically include a closed-loop chain on a drive sprocket and an idler pulley (or idler wheel) operably connected to a tensioner assembly. These chassis components also include multiple roller assemblies between the drive sprocket and the idler pulley, configured to guide the chain during movement. The roller assemblies typically include one or more upper roller assemblies and multiple lower roller assemblies.

[0004] Chains typically consist of multiple joints; the term joint refers to a single component of the chain that is hinged to other parts. Typically, each joint includes a pair of links facing each other. These joints are interconnected by pins. Each pin is typically inserted into a hole included in a link and connects the two joints together. A sole is usually mounted on the joint, which is in direct contact with the ground and has the function of releasing traction to the ground and increasing the contact surface between the machine and the ground. The type of sole used depends on the ground on which the machine must operate, the environmental conditions under which the machine must operate, and the specifications recommended by the machine manufacturer.

[0005] Each roller assembly typically includes a roller body through which a shaft passes. The roller body is defined by a radially inner surface facing the shaft and spaced apart from the shaft by a radial clearance. The roller body is rotatable about the shaft, which is fixed relative to the frame of the chassis on which the roller body is mounted.

[0006] To ensure the roller body rotates correctly relative to its respective axis by transmitting load between the roller body and the shaft, an active rolling bearing can be placed in the radial clearance between the shaft and the roller body. As an alternative to the rolling bearing in the clearance, a bushing fitted inside the roller body can be provided. The bushing is typically made of a non-ferrous metal (e.g., bronze) or a bimetallic alloy. The radial clearance is typically filled with lubricant to further reduce friction or dissipate heat generated by friction between the bushing and the roller body and / or the bushing and the shaft contact surfaces, or by dissipating heat generated by the rotation of the ball bearing's swivel rings.

[0007] At the axial end of the roller body, two axial end supports are inserted into the shaft and roller body assembly. These two axial end supports are mounted on the shaft and function to close the radial clearance between the shaft and the roller body.

[0008] To ensure a liquid-tight seal of the radial clearance between the shaft and the roller body, preventing lubricant leakage from the radial clearance and preventing dirt, water, or other contaminants from the external environment from reaching the radial clearance, an active seal body is installed between the axial end bearing support and the roller body.

[0009] Each sealing body acts axially between a corresponding end support and the roller body, and typically consists of a generally annular first half inserted into a seat in the axial end support and a similarly generally annular and substantially mirror-image second half inserted into a seat in the roller body. Each half is inserted into its corresponding seat by a corresponding spring element (typically an O-ring) interposed between the seats, the spring element applying an axial thrust.

[0010] The two half-parts face each other axially at their corresponding sliding contact surfaces. These sliding contact surfaces are machined to remove any roughness, making them as smooth as possible. The two sliding contact surfaces are positioned in contact with each other in such a way that they act as the axial contact interface between the axial end support and the roller body. The two sliding contact surfaces remain axially pressed against each other, ensuring a fluid seal between the two half-parts during rotation of the second half-part (integrated with the roller body) relative to the first half-part (integrated with the shaft). Specifically, the two sliding contact surfaces are held axially pressed against each other under a predetermined load, calculated in such a way that one half-part is allowed to rotate relative to the other half, while simultaneously preventing the passage of liquid and impurities between the two sliding contact surfaces.

[0011] To ensure that the two sliding contact surfaces are fitted with a predetermined load, an axial end support is embedded in the shaft, thereby bringing the axial end support axially closer to the roller body until a predetermined design distance from the roller body is reached. This predetermined design distance is calculated such that the two sliding contact surfaces come into contact with each other, and the elastic element applies an axial thrust equal to the aforementioned predetermined load.

[0012] The applicant has noted that the sealing bodies described above can limit the performance of the roller assembly; in fact, the applicant has verified that sliding contact between these half-parts of the sealing bodies occurs between the metal parts, which can lead to overheating and limit the maximum rotational speed of the roller.

[0013] The applicant has felt the need to create a roller assembly with a higher maximum rotational speed.

[0014] The applicant has recognized that if the oil is removed from the cavity, a liquid seal will not be necessary.

[0015] The applicant has discovered that by using one or more solid oil bearings, it will no longer be necessary to fill the cavity with oil.

[0016] However, the applicant has recognized that while completely removing these sealing bodies would eliminate the sliding contact between the components that limit the maximum rotational speed, it would simultaneously allow external contaminants to penetrate the radial gap between the shaft and the roller body, causing wear and / or corrosion of these components.

[0017] The applicant has discovered that if a seal (which does not guarantee a perfect liquid seal) is used to prevent the entry of external contaminants, it may be possible to avoid sliding contact between the metal bodies that limit the maximum rotational speed. Summary of the Invention

[0018] The present invention therefore relates to a tracked chassis roller assembly.

[0019] A roller body is provided having an inner cavity extending axially from a first inlet opening to a second inlet opening.

[0020] A shaft is provided that is inserted into the cavity of the roller body and extends axially from a first end portion to a second end portion.

[0021] A first end support is provided, which is attached to the first end portion of the shaft at the first inlet opening, and the first end support includes a cylindrical radial outer surface.

[0022] A second end support is provided, which is attached to a second end portion of the shaft at the second inlet opening, and the second end support includes a cylindrical radial outer surface.

[0023] A first rotary lip seal is provided, which is attached to the roller body at the first inlet opening, and the first rotary lip seal includes a main sealing lip that slides adjacent to the radially outer surface of the first support.

[0024] A second rotary lip seal is provided, which is attached to the roller body at the second inlet opening, and the second rotary lip seal includes a main sealing lip that slides abutting against the radially outer surface of the second support.

[0025] At least a first solid oil rolling bearing is provided, which is located in the cavity and includes a radially inner rotating ring coupled to the shaft and a radially outer rotating ring coupled to the roller body.

[0026] The applicant discovered that by connecting the roller body to the shaft via a solid oil bearing, the lubricant is retained within the bearing and the cavity does not need to be filled with oil.

[0027] The first and second rotating lip seals enclose the inner cavity to prevent external contaminants from entering, which could wear or corrode the roller assembly and thus affect its operation.

[0028] The applicant noted that these sealing lips slide on the support body without causing sliding contact between metal parts, thus enabling operation at higher speeds than conventional seals.

[0029] In fact, the applicant has demonstrated that the rotary lip seals effectively prevent external contaminants from entering the inner cavity, and because they do not have sliding contact between two metal components, they can operate at higher rotational speeds than conventional seals.

[0030] The terms “axial,” “axially,” “radial,” and “radially” are used relative to the axis of rotation of the roller assembly.

[0031] Specifically, the terms "axial" and "axially" refer to a reference / quantity arranged / measured or extended in a direction parallel to or coinciding with the axis of rotation of the roller assembly.

[0032] The terms "axially inside / outside" refer to the locations of points closer to and further away from roller assemblies placed along the axis of rotation and equidistant from the axial ends of multiple shafts, respectively.

[0033] The terms “radial” and “radially” refer to a reference / quantity arranged / measured or extended in a direction perpendicular to the axis of rotation of the roller assembly.

[0034] The terms "radial interior" and "radial exterior" refer to positions closer to or further away from the aforementioned axis of rotation, respectively.

[0035] The term “radial overlap” refers to the relative positioning of two components such that the first component is placed radially outward relative to the second component, and such that a radial plane intercepts and passes through the first and second components.

[0036] When two components are involved, the term "radial alignment" refers to the relative positioning of the two components such that the first component is positioned radially outward relative to the second component, and wherein both the first component and the second component extend in the axial direction between a first radial plane and a second radial plane. The two radially aligned components have the same extension in the axial direction.

[0037] When two components are involved, the term “partially radially aligned” refers to the relative positioning of the two components such that the first component is placed radially outward relative to the second component, and wherein two radially spaced apart from each other by axes intercept and pass through the first and second components.

[0038] When referring to points of two components, the term "radial alignment" means the relative positioning between the two components such that the first component is placed radially outward relative to the second component, and the radial plane passes through two points of the two components.

[0039] The term "grafting" refers to the joining of two parts or components through an interference fit, wherein the two parts or components are constrained to each other with respect to rotation and translation.

[0040] The term "rigid" refers to components made of materials such as steel that have a Young's modulus greater than 1000 MPa.

[0041] The track chassis roller assembly of the present invention may include one or more of the following features, either individually or in combination.

[0042] Preferably, all components of the first rotating lip seal are rotatably integrated with the roller body.

[0043] Preferably, all components of the second rotating lip seal are rotatably integrated with the roller body.

[0044] Therefore, the sliding seal contact is positioned between the sealing lip and the shaft support.

[0045] Preferably, a second solid oil bearing is provided, which is placed in the cavity and axially spaced from the first solid oil bearing, the second solid oil bearing including a radially inner swivel ring connected to the shaft and a radially outer swivel ring connected to the roller body.

[0046] Preferably, the roller body includes a first shoulder located in the cavity and facing the first inlet opening.

[0047] Preferably, the roller body includes a second shoulder located in the cavity and facing the second inlet opening.

[0048] Preferably, an annular nut is present, which is mounted on the shaft and configured to axially fasten the first bearing against the first shoulder.

[0049] Preferably, the roller body further includes a retainer mounted on the shaft and configured to axially abut the second bearing on the side opposite to the annular nut.

[0050] Preferably, the roller body includes a first body and a second body, the first shoulder being defined on the first body, and the second body being different from the first body, the second shoulder being defined on the second body.

[0051] Preferably, the roller includes a third body, which is different from the first body and the second body, and is axially inserted between the first body and the second body.

[0052] Preferably, the first body, the second body, and the third body are mechanically connected by interference fit or placed in a simple adjacent manner.

[0053] In this way, the ring nut and retainer fasten the different bodies that form the roller body, fixing them together without the need for welding.

[0054] Preferably, the roller body includes a first sealing seat located at the first inlet opening.

[0055] Preferably, the roller body includes a second sealing seat located at the second inlet opening.

[0056] Preferably, the first rotary lip seal includes a rigid connecting body that is interlocked into the first sealing seat.

[0057] Preferably, the first rotary lip seal includes a main sealing body, which is connected to the connecting body and includes the main sealing lip of the first rotary seal.

[0058] Preferably, the second rotary lip seal includes a coupling body that is interlocked into the second sealing seat.

[0059] Preferably, the second rotary lip seal includes a main sealing body, which is connected to the connecting body and includes the main sealing lip of the second rotary seal.

[0060] Preferably, the connecting body of the first rotary lip seal includes a cylindrical wall and a flange.

[0061] Preferably, the first rotary lip seal includes an auxiliary sealing body, which is axially inserted between the main sealing body and the flange of the first rotary lip seal and radially inserted between the cylindrical wall and the first support member. The auxiliary sealing body includes a radial inner surface, which is slidably placed abutting against the first support member.

[0062] Preferably, the radial inner surface of the auxiliary sealing body of the first rotary lip seal is cylindrical.

[0063] Preferably, the connecting body of the second rotary lip seal includes a cylindrical wall and a flange.

[0064] Preferably, the second rotary lip seal includes an auxiliary sealing body, which is axially inserted between the main sealing body and the flange of the second rotary lip seal and radially inserted between the cylindrical wall and the second support. The auxiliary sealing body includes a radial inner surface, which is slidably placed abutting against the second support.

[0065] Preferably, the radial inner surface of the auxiliary sealing body of the second rotary lip seal is cylindrical.

[0066] Preferably, the auxiliary sealing body of the first rotary lip seal and / or the second rotary lip seal has a rectangular or square shape in a radial cross-sectional view.

[0067] The auxiliary sealing body improves the sealing of the rotary lip seal when there is axial clearance between the shaft and the roller body.

[0068] Preferably, the first rotary lip seal includes a garter spring configured to abut against the first support to secure the corresponding main sealing lip.

[0069] Preferably, the second rotary lip seal includes an annular helical spring configured to abut against the second support to secure the corresponding main sealing lip.

[0070] Preferably, the first rotary lip seal includes an auxiliary sealing lip that slides abut against the radially outer surface of the first support.

[0071] Preferably, the second rotary lip seal includes an auxiliary sealing lip that slides abut against the radially outer surface of the second support.

[0072] Preferably, the auxiliary sealing lip of the first rotary lip seal is axially inserted between the main sealing lip and the auxiliary sealing body.

[0073] Preferably, the auxiliary sealing lip of the second rotary lip seal is axially inserted between the main sealing lip and the auxiliary sealing body.

[0074] Preferably, the main sealing body of the first rotary lip seal includes a connecting portion that is placed in contact with the corresponding connecting body.

[0075] Preferably, the first rotary lip seal includes a rigid insert configured to radially press the coupling portion against the coupling body.

[0076] Preferably, the rigid insert is inserted into the gap between the main sealing lip of the first rotary lip seal and the connection portion of the main sealing body.

[0077] Preferably, the main sealing body of the second rotary lip seal includes a connecting portion that is placed in contact with the corresponding connecting body.

[0078] Preferably, the second rotary lip seal includes a rigid insert configured to radially press the coupling portion against the coupling body.

[0079] Preferably, the rigid insert is inserted into the gap between the main sealing lip of the second rotary lip seal and the connection portion of the main sealing body. Attached Figure Description

[0080] Other features and advantages of the invention will become more apparent from the following description of preferred embodiments of the invention with reference to the accompanying drawings. In these drawings:

[0081] Figure 1 This is a schematic side view of a tracked chassis;

[0082] Figure 2 It is based on the present invention Figure 1 A schematic cross-sectional view of the tracked chassis roller assembly;

[0083] Figure 3 yes Figure 2 A magnified view showing the details of the schematic diagram;

[0084] Figure 4 yes Figure 2 An enlarged view of another detail of the schematic diagram. Detailed Implementation

[0085] Figure 1 This is a schematic side view showing some components of a tracked chassis. The tracked chassis 10 includes two track assemblies 11, in... Figure 1 Only one track assembly is visible in the figure. Each track assembly 11 includes a chain 12, a return wheel 14, and a drive wheel 16. The chain 12 includes multiple links 13 interconnected therebetween by pins and bushings (not shown). The return wheel 14 is partially hidden by the crankcase 15 in the figure. Multiple roller assemblies 17 are arranged between the return wheel 14 and the drive wheel 16. Specifically, one or more upper roller assemblies and multiple lower roller assemblies are arranged to contact the links 13 and adapt to guide the movement of the chain 12.

[0086] The lower roller assembly 17 is arranged in the lower portion of the track assembly 11 and configured to transmit load between the track and the chassis frame (not shown). The upper roller assembly 17 is configured to guide the chain between the drive wheel 16 and the return wheel 14, and is typically present in fewer numbers than the lower roller assemblies. The number of lower roller assemblies 17 varies depending on the type and weight of the machine.

[0087] See Figure 2 This illustrates a preferred embodiment of the lower roller assembly 17 according to the present invention. Specifically, Figure 2 This is a cross-sectional view of the lower roller assembly 17. The cross-section is a longitudinal plane that is transverse to the chain link 13 of the chain 12 and therefore transverse to the direction of movement of the track chassis, passing through the rotation axis X of the roller assembly 17.

[0088] The roller assembly 17 includes a roller body 18, which includes an inner cavity 19 extending axially from a first entry opening 18a to a second entry opening 18b. The first entry opening 18a and the second entry opening 18b are located at opposite axial ends of the roller body 18.

[0089] The roller body 18 consists of three separate bodies: a first body 19a, a second body 19b, and a third body 19c. The first body 19a, the second body 19b, and the third body 19c are connected together by an interference fit or simply placed side by side. The third body 19c is axially inserted between the first body 19a and the second body 19b.

[0090] The roller body 18 is defined by a radial inner surface 20 and a radial outer surface 21. The radial inner surface 20 defines an inner cavity 19 in the radial outward direction. The shape of the radial outer surface 21 is determined by the type of chain 12 with which the roller assembly 17 must interact.

[0091] The roller body 18 is preferably made of low-alloy steel that has been boron alloyed and subjected to at least one heat treatment. Low-alloy steel is steel in which elements other than iron and carbon are present, and none of these other elements are present in amounts greater than 5%.

[0092] The roller assembly 17 also includes a shaft 22 inserted into the cavity 19 of the roller body 18. The shaft 22 extends between a first axial end portion 22a and a second axial end portion 22b and has a radially outer surface 23 facing the radially inner surface 20 of the roller body 18.

[0093] Shaft 22 is preferably made of boron alloy low alloy steel that has undergone at least one heat treatment or micro alloy steel that does not require any heat treatment.

[0094] The axial extension of shaft 22 is longer than its axial extension in the roller body 18. Shaft 22 protrudes slightly from the first entry opening 18a and the second entry opening 18b.

[0095] The shaft 22 is rigidly connected to the chassis frame via a first end support 24 at the first axial end portion 22a, or to a chassis component integrated with the chassis frame.

[0096] The first end support 24 is at least partially inserted into the inner cavity 19 at the first entry opening 18a.

[0097] The first end support 24 includes a smooth cylindrical radially outer surface 24a that faces the radially inner surface 20 at the first entry opening 18a. The radially outer surface 24a extends about the axis of rotation X.

[0098] The first end support 24 has an internal cavity 25. The shaft 22 is inserted into the internal cavity 25 at its first axial end portion 22a.

[0099] The shaft 22 is rigidly connected to the chassis frame via a second end support 26 at the second axial end portion 22b, or to a chassis component integrated with the chassis frame.

[0100] The second end support 26 is at least partially inserted into the inner cavity 19 at the second inlet opening 18b.

[0101] The second end support 26 includes a smooth cylindrical radially outer surface 26a that faces the radially inner surface 20 at the second entry opening 18a. The radially outer surface 26a extends about the axis of rotation X.

[0102] The second end support 26 has an internal cavity 27. The shaft 22 is inserted into the internal cavity 27 at its second axial end portion 22b.

[0103] Shaft 22 is integrated with both the first end support 24 and the second end support 26.

[0104] The first support 24 is fixed to the shaft 22 at the first end portion 22a, for example by a pin (not shown) inserted into a corresponding aligned radial hole (not shown) formed in the first support 25 and the shaft 22.

[0105] This prevents any axial movement of the shaft 22 relative to the first end support 24 and any rotation about the axis of rotation X.

[0106] Similarly, the second support 26 is fixed to the shaft 22 at the second end portion 22b, for example by a pin (not shown) inserted into a corresponding aligned radial hole (not shown) formed in the second support 26 and the shaft 22.

[0107] This prevents any axial movement of shaft 22 relative to the second end support 26 and any rotation about the axis of rotation X.

[0108] The first support member 24 and the second support member 26 are preferably made of steel or spherical cast iron.

[0109] The roller body 18 can be rotatably mounted relative to the shaft 22 about the rotation axis X.

[0110] The first rolling bearing 31 and the second rolling bearing 32 are disposed in the inner cavity 19 of the roller body 18, and function between the shaft 22 and the radial inner surface 20 of the roller body 18 (e.g., Figure 2 (As shown).

[0111] The first and second bearings 31 and 32 are solid oil type.

[0112] The first bearing 31 includes an inner rotating ring 31a mounted on the shaft 22 and an outer rotating ring 31b inserted into the roller body 18. A sealed bearing cavity 31c is defined between the inner rotating ring 31a and the outer rotating ring 31b, in which a plurality of rolling elements 31d (e.g., tapered rollers) are radially accommodated. The bearing cavity 31c is filled with a solid lubricant, i.e., a porous polymer impregnated with a suitable liquid lubricant.

[0113] Similarly, the second bearing 32 includes an inner swivel ring 32a mounted on the shaft 22 and an outer swivel ring 32b inserted into the roller body 18. A sealed bearing cavity 32c is defined between the inner swivel ring 32a and the outer swivel ring 32b, in which a plurality of rolling elements 32d (e.g., tapered rollers) are radially accommodated. The bearing cavity 32c is filled with a solid lubricant, i.e., a porous polymer impregnated with a suitable liquid lubricant.

[0114] During rotation, the porous polymer and liquid lubricant are heated, and the liquid lubricant is released into the bearing cavities 31c and 32c. When the bearings 31 and 32 cool down, the liquid lubricant is reabsorbed by the porous polymer.

[0115] The roller body 18 includes a first shoulder 33a formed in the inner cavity 19 and facing the first inlet opening 18a. The first shoulder 33a is formed on the first body 19a.

[0116] The roller body 18 also includes a second shoulder 33b, which is formed in the inner cavity 19 and faces the second inlet opening 18b. The second shoulder 33b is formed on the second body 19b.

[0117] The two shoulders 33a and 33b face opposite sides.

[0118] The first bearing 31 is inserted into the inner cavity 19. Its inner rotating ring 31a is preferably mechanically interference-fitted onto the shaft 22. Its outer rotating ring 31b is preferably mechanically interference-fitted to the radial inner surface 20. The outer rotating body 31b is placed adjacent to and abuts against the first shoulder 33a.

[0119] Similarly, the second bearing 32 is inserted into the inner cavity 19. Its inner swivel ring 32a is preferably mechanically interference-fitted onto the shaft 22. Its outer swivel ring 32b is preferably mechanically interference-fitted to the radial inner surface 20. The outer swivel ring 32b is placed abutting against the second shoulder 33.

[0120] An annular nut 34 is mounted to the shaft 22 between the first end portion 22a and the first bearing 31. The annular nut 34 is threaded onto the shaft 22. The annular nut 34 is axially adjustable by tightening / loosening. The annular nut 34 is configured to secure the first bearing 31 against the first shoulder 33a. A washer 34a is inserted between the annular nut 34 and the first bearing 31. The annular nut 34 is configured to apply an axial force to the inner swivel ring 31a of the first bearing 31, causing the corresponding outer swivel ring 31b to press against the first shoulder 33a.

[0121] A retainer 34b is mounted on the shaft 22 between the second end portion 22b and the second bearing 32. The retainer 34b includes a retaining ring. The retainer 34b is axially fixed to the shaft 22. The retainer 34b is configured to axially stop the second bearing 32, specifically by means of an abutment on its inner swivel ring 32a. A spacer 34c is placed between the retainer 34b and the second bearing 32.

[0122] When the annular nut 34 is tightened axially along the shaft 22, the first bearing 32 is pressed against the first shoulder 33a by the annular nut 34, while the second bearing 32 is pressed against the second shoulder 33b and stopped by the retainer 34c. Furthermore, the first body 19a is pressed against the third body 19c via the first shoulder 33a, while the third body 19c is pressed against the second body 19b, which is stopped by the second bearing 32, via the second shoulder 33b.

[0123] In this way, the first body 19a, the second body 19b, and the third body 19c are held together.

[0124] The inner cavity 19 of the roller body 18 is closed at the first end support 24 and the second end support 26.

[0125] For this purpose, there are a first rotary lip seal 35 and a second rotary lip seal 36.

[0126] The first rotary lip seal 35 is positioned axially outward relative to the first bearing 31. Similarly, the second rotary lip seal 36 is positioned axially outward relative to the second bearing 32.

[0127] The first rotary lip seal 35 is configured to close the gap between the radially inner surface 20 of the roller body 18 and the radially outer surface 24a of the first support 24 at the first inlet opening 18a. The first rotary lip seal 35 is positioned in sliding contact with the radially outer surface 24a so as to slide thereon during rotation of the roller body 18.

[0128] A first rotary lip seal 35 is housed in a first sealing seat 35a, which is formed on the radially inner surface 20 in a cavity 19 of the roller body 18 and faces the first inlet opening 18a. The first sealing seat 35a includes a cylindrical surface 35b and a shoulder 35c.

[0129] exist Figure 3 The first rotary lip seal 35 shown in the cross-sectional view includes a rigid, preferably metallic, connecting body 38. The connecting body 38 is inserted into a first sealing seat 35a, preferably with an interference fit. The connecting body 38 includes a cylindrical wall 39 abutting against a cylindrical surface 35b, preferably with a mechanical interference fit, and a flange 40 abutting against a shoulder 35c.

[0130] The first rotary lip seal 35 includes a main sealing body 41. The main sealing body 41 is made of a polymeric material, preferably elastic, such as nitrile rubber. The sealing body 41 is arranged radially inside the cylindrical wall 39.

[0131] The sealing body 41 includes a connecting portion 42 that rests against the cylindrical wall 39.

[0132] The main sealing body 41 also includes a main sealing lip 43. The main sealing lip 43 is a conventional sealing lip. The main sealing lip 43 protrudes radially toward and slides against the first support member 24. Specifically, the main sealing lip 43 slides against the radially outer surface 24a of the first support member 24.

[0133] The main sealing body 41 also includes an auxiliary sealing lip 44. The auxiliary sealing lip 44 is axially offset outward relative to the main sealing lip 43. The auxiliary sealing lip 44 is also a conventional sealing lip. The auxiliary sealing lip 44 protrudes radially toward and slidably abuts against the first support member 24. Specifically, the auxiliary sealing lip 44 is slidably abutted against the radially outer surface 24a of the first support member 24.

[0134] The first rotary lip seal 35 also includes a rigid insert 45. The rigid insert 45 is a flange ring. The rigid insert 45 is radially inserted between the connecting portion 42 and the main sealing lip 43. The rigid insert 45 is placed against the main sealing body 41 and is configured to press the connecting portion 42 against the cylindrical wall 39 to adhere the connecting portion 42 to the cylindrical wall 39.

[0135] The first rotary lip seal 35 also includes an annular helical spring 46. The annular helical spring 46 is positioned circumferentially around the main sealing lip 43. The annular helical spring 46 is configured to pull the main sealing lip 43 against the first support member 24.

[0136] The first rotary lip seal 35 includes an auxiliary sealing body 47. The auxiliary sealing body 47 is axially inserted between the main sealing body 41 and the flange 40. The auxiliary sealing body 47 is radially inserted between the cylindrical wall 39 and the first support member 24. The auxiliary sealing body 47 is made of a polymer material, preferably an elastic material, such as nitrile rubber. The auxiliary sealing body 47 includes a radially inner surface 48 that is slidably placed against a radially outer surface 24a.

[0137] Similarly, the second rotary lip seal 36 is configured to close the gap between the radially inner surface 20 of the roller body 18 and the radially outer surface 26a of the second support 26 at the second inlet opening 18b. The second rotary lip seal 36 is slidably positioned in contact with the radially outer surface 26a so as to slide thereon during rotation of the roller body 18.

[0138] The second rotary lip seal 36 is housed in the second sealing seat 36a, which is formed on the radially inner surface 20 in the cavity 19 of the roller body 18 and faces the second inlet opening 18b. The second sealing seat 36a includes a cylindrical surface 35b and a shoulder 35c.

[0139] exist Figure 4 The second rotary lip seal 36, shown in the cross-sectional view, includes a rigid, preferably metallic, connecting body 49. The connecting body 49 is inserted into the second sealing seat 36a, preferably with an interference fit. The connecting body 49 includes a cylindrical wall 50 abutting against a cylindrical surface 36b, preferably with a mechanical interference fit, and a flange 51 abutting against a shoulder 36c.

[0140] The second rotary lip seal 36 includes a main sealing body 52. ​​The main sealing body 52 is made of a polymeric material, preferably elastic, such as nitrile rubber. The main sealing body 52 is arranged radially inside the cylindrical wall 52.

[0141] The main sealing body 52 includes a connecting portion 53 that rests against the cylindrical wall 50.

[0142] The main sealing body 52 also includes a main sealing lip 54. The main sealing lip 54 is a conventional sealing lip. The main sealing lip 54 projects radially toward and slidably abuts against the second support 26. Specifically, the main sealing lip 54 slidably abuts against the radially outer surface 26a of the second support 26.

[0143] The main sealing body 52 also includes an auxiliary sealing lip 55. The auxiliary sealing lip 55 is axially offset outward relative to the main sealing lip 54. The auxiliary sealing lip 55 is also a conventional sealing lip. The auxiliary sealing lip 55 protrudes radially toward and slidably abuts against the second support member 26. Specifically, the auxiliary sealing lip 55 is slidably abutted against the radially outer surface 26a of the second support member 26.

[0144] The second rotary lip seal 36 also includes a rigid insert 56. The rigid insert 56 is a flange ring. The rigid insert 56 is radially inserted between the connecting portion 53 and the main sealing lip 54. The rigid insert 56 is placed against the main sealing body 52 and is configured to press the connecting portion 53 against the cylindrical wall 50 to adhere the connecting portion 53 to the cylindrical wall 50.

[0145] The second rotary lip seal 36 also includes an annular helical spring 57. The annular helical spring 57 is positioned circumferentially around the main sealing lip 54. The annular helical spring 57 is configured to pull the main sealing lip 54 against the second support member 26.

[0146] The second rotary lip seal 36 includes an auxiliary sealing body 58. The auxiliary sealing body 58 is axially inserted between the main sealing body 52 and the flange 51. The auxiliary sealing body 58 is radially inserted between the cylindrical wall 50 and the second support member 26. The auxiliary sealing body 58 is made of a polymer material, preferably an elastic material, such as nitrile rubber. The auxiliary sealing body 58 includes a radially inner surface 59, which is slidably placed against the radially outer surface 26a.

Claims

1. Tracked chassis roller assembly (17), comprising: Roller body (18) having an internal cavity (19) extending axially from a first inlet opening (18a) to a second inlet opening (18b). Shaft (22), which is inserted into the cavity (19) of the roller body (18) and extends axially from the first end portion (22a) to the second end portion (22b); A first end support (24) is attached to the first end portion (22a) of the shaft (22) at the first inlet opening (18a), and the first end support (24) includes a cylindrical radial outer surface (24a). The second end support (26) is attached to the second end portion of the shaft (22) at the second access opening (18b), and the second end support (26) includes a cylindrical radial outer surface (26a). A first rotary lip seal (35) is attached to the roller body (18) at the first inlet opening (18a) and includes a main sealing lip (43) that slides against the radial outer surface (24a) of the first support (24). A second rotary lip seal (36) is attached to the roller body (18) at the second inlet opening (18b), and the second rotary lip seal (36) includes a main sealing lip (49) that slidably abuts against the radially outer surface (26a) of the second support (26); and At least a first solid oil rolling bearing (31) is located in the inner cavity (19) and includes a radial inner swivel ring (31a) connected to the shaft (22) and a radial outer swivel ring (31b) connected to the roller body (18).

2. The track chassis roller assembly (17) according to claim 1, comprising a second solid oil rolling bearing (32) placed in the inner cavity (19) and axially spaced apart from the first bearing (31), the second bearing (32) comprising a radially inner rotating ring (32a) connected to the shaft (22) and a radially outer rotating ring (32b) connected to the roller body (18).

3. The chassis roller assembly (17) according to claim 2, wherein, The roller body (18) includes a first shoulder (33a) and a second shoulder (33b), the first shoulder (33a) being located in the inner cavity (19) and facing the first entry opening (18a), and the second shoulder (33b) being located in the inner cavity (19) and facing the second entry opening (18b). The roller assembly (17) includes an annular nut (34) mounted on the shaft (22) and configured to axially fasten the first bearing (31) against the first shoulder (33a). The roller assembly (17) also includes a retainer (34b) mounted on the shaft (22) and configured to axially abut the second bearing (32) on the side opposite to the annular nut (34).

4. The chassis roller assembly (17) according to claim 3, wherein, The roller body (18) includes a first body (19a) and a second body (19b), the first shoulder (33a) being defined on the first body (19a), the second body (19b) being different from the first body (19a), and the second shoulder (19b) being defined on the second body (19b).

5. The chassis roller assembly (17) according to claim 4, wherein, The roller body (18) includes a third body (19c), which is different from the first body (19a) and the second body (19b), and is axially inserted between the first body (19a) and the second body (19b).

6. The chassis roller assembly (17) according to claim 5, wherein, The first body (19a), the second body (19b) and the third body (19c) are mechanically interference-fitted and / or placed in a simple mutually supportive manner, and are fastened between the first bearing (31) and the second bearing (32).

7. The chassis roller assembly (17) according to any one of the preceding claims, wherein, The roller body (18) includes a first sealing seat (35a) located at the first inlet opening (18a) and a second sealing seat (36a) located at the second inlet opening (18b). The first rotary lip seal (35) includes: A rigid connecting body (38), which is interlocked with the first sealing seat (35a), and The main sealing body (41) is connected to the connecting body (38) and includes the main sealing lip (43) of the first rotary lip seal (35). The second rotary lip seal (36) includes: The connecting body (49) is interlocked with the second sealing seat (36a), and The main sealing body (52) is connected to the connecting body (49) and includes the main sealing lip (54) of the second rotary lip seal (36).

8. The chassis roller assembly (17) according to claim 7, wherein: The connecting body (38) of the first rotary lip seal (35) includes a cylindrical wall (39) and a flange (40). The first rotary lip seal (35) includes an auxiliary sealing body (47) which is axially inserted between the main sealing body (41) and the flange (40) of the first rotary lip seal (35) and radially inserted between the cylindrical wall (39) and the first support (24). The auxiliary sealing body (47) includes a radial inner surface (48) which is slidably placed abutting against the first support (24). The connecting body (49) of the second rotary lip seal (36) includes a cylindrical wall (50) and a flange (51). The second rotary lip seal (36) includes an auxiliary sealing body (58) which is axially inserted between the main sealing body (52) and the flange (51) of the second rotary lip seal (36) and radially inserted between the cylindrical wall (50) and the second support (26). The auxiliary sealing body (58) includes a radial inner surface (59) which is slidably placed abutting against the second support (26).

9. The chassis roller assembly (17) according to any one of the preceding claims, wherein, The first rotary lip seal (35) includes an annular helical spring (46) configured to tighten the corresponding main sealing lip (43) against the first support (24), and the second rotary lip seal (36) includes an annular helical spring (57) configured to tighten the corresponding main sealing lip (54) against the second support (26).

10. The chassis roller assembly (17) according to any one of the preceding claims, wherein, The first rotary lip seal (35) includes an auxiliary sealing lip (44) that slides abut against the radial outer surface (24a) of the first support (24), and the second rotary lip seal (36) includes an auxiliary sealing lip (55) that slides abut against the radial outer surface (26a) of the second support (26).

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