A limiting tool for pusher oil seal installation

Abstract

This utility model belongs to the field of tobacco technology, specifically relating to a limiting fixture for installing oil seals in a pusher. It is suitable for installing two oil seals at a preset axial distance in a shaft hole. The fixture includes a fixture body, which sequentially comprises a guide section, a bearing section, and a stepped shoulder. The stepped shoulder serves as a limiting reference for oil seal installation. The outer peripheral wall of the bearing section has multiple circumferentially distributed claws, forming a clamping cavity between the claws and the bearing section for holding the oil seals. The claws also have a radially elastic opening structure to bend the oil seals into a shape suitable for insertion. The fixture also includes a detachable positioning and limiting structure, namely a steel ring fitted around the outer periphery of the fixture body. The distance between the steel ring and the stepped shoulder controls the installation position spacing of the two oil seals. This fixture has a simple structure, precise positioning, and enables rapid, stable, and equidistant installation of oil seals, making it suitable for the installation of high-precision shaft hole seals.

Description

Technical Field

[0001] This utility model relates to the field of tobacco processing equipment technology, specifically to a limiting tool for installing an oil seal on a pusher. Background Technology

[0002] The pusher in the FOCKE 350 hard-pack packaging machine is mainly used to push the shaped cigarette packs or paper boxes out of the drying drum mold and convey them to the downstream conveyor belt. The core components of the pusher include the push shaft and the oil-immersion lubrication mechanism. The push shaft passes through a shaft hole in the oil-immersion lubrication mechanism mounted on the frame and performs reciprocating linear motion within this hole. To ensure sufficient lubrication of the push shaft during high-speed, long-term operation, lubricating oil fills the gap between the shaft hole and the push shaft, forming a lubricating film to reduce friction and wear between the shaft and the shaft hole, ensuring the long-term stable operation of the pusher. Therefore, ensuring good lubricating oil sealing performance between the shaft hole and the push shaft in the oil-immersion lubrication mechanism is crucial to preventing lubricating oil leakage and the intrusion of external impurities, thereby effectively maintaining the integrity of the lubrication system and the stability of the pusher equipment.

[0003] For this purpose, two oil seals are installed at both ends of the shaft hole. The inner oil seal is close to the inside of the equipment to prevent lubricating oil from leaking inward, and the outer oil seal is close to the outside of the oil-immersed lubrication mechanism to prevent dust and scrape oil to the return oil groove. A closed cavity is formed between the two oil seals for oil storage and return.

[0004] The industry commonly uses SKF tools for hammering installation of oil seals, but traditional hammering installation has several technical problems: First, hammering can easily cause the oil seal to tilt or misalign with the shaft, resulting in uneven contact surfaces and local gaps, causing uneven stress and local wear on the oil seal lip, accelerating seal failure and oil leakage; Second, the axial positioning of the inner and outer oil seal elements is difficult to control precisely, and the impact of hammering may cause the relative position of the oil seal to shift, leading to errors in the designed axial spacing, which in turn causes abnormalities in the volume and pressure distribution of the lubricating oil cavity, affecting the lubrication effect and the oil seal's load-bearing capacity, and increasing the risk of oil leakage; Finally, mismatched or improper hammering tools may damage the oil seal body, including edge extrusion deformation, metal shell deformation and scratches, reducing the integrity of the oil seal installation and sealing performance, further exacerbating the risk of leakage.

[0005] It is worth noting that in the pusher of the FOCKE 350 rigid box packaging machine, the distance between the two oil seals must be maintained at approximately 30 mm to ensure proper pre-tightening of the oil seal lips and maintain a stable oil film thickness. When the axial distance deviates from the design value, abnormal oil film flow may occur: if the axial distance is too large, the lubricating oil is prone to uncontrolled flow or leakage between the two oil seals; if the axial distance is too small, the compressive force between the two oil seals increases, leading to increased friction loss. However, existing SKF installation tools cannot achieve precise control of the axial distance between the two oil seals.

[0006] In summary, existing oil seals are mostly positioned by being hammered in with general installation tools, which makes it difficult to ensure coaxiality and spacing control, affecting the stability and reliability of the sealing system.

[0007] This application is submitted to address the above issues. Utility Model Content

[0008] The technical solution adopted in this utility model is as follows:

[0009] A limiting fixture is provided for installing oil seals in a pusher, suitable for installing two oil seals at a preset axial distance in a shaft hole A. The fixture includes:

[0010] The tooling body has a guide section 1, a bearing section 2 and a stepped shoulder 3 arranged sequentially at one end. The stepped shoulder 3 is used as the installation limit reference for oil seal B.

[0011] The outer peripheral wall of the bearing section 2 is provided with a plurality of circumferentially distributed claws 21. The claws 21 and the bearing section 2 form a clamping cavity for clamping the oil seal B. The claws 21 have a radially elastically openable structure for bending the oil seal B into a lip or petal shape so that it can enter the shaft hole A.

[0012] The tooling body is also provided with a positioning and limiting structure, which is a steel ring 4 that can be detachably sleeved on the outer peripheral wall of the tooling body. The top surface of the steel ring 4 abuts against the stepped shoulder 3, and the distance between the bottom surface and the stepped shoulder is a preset axial spacing, which is used to control the installation position spacing of the two oil seals B.

[0013] Preferably, the outer diameter of the guide section 1 is smaller than the inner diameter of the shaft hole A, which is used to guide the tooling to align with the shaft hole and insert smoothly;

[0014] The maximum outer diameter of the bearing section 2 is not greater than the inner diameter of the shaft hole A. The outer diameter of the combined structure after the claw 21 clamps the oil seal B is greater than the inner diameter of the shaft hole A. During installation, it can radially shrink and deform under the action of external force to achieve insertion into the shaft hole. Specifically, during installation, it is squeezed by external force to form an interference fit. During the process of entering the shaft hole, the inner wall of the shaft hole applies a radial compressive force to the claw. When the oil seal reaches the mounting groove of the shaft hole A, the radial compressive force applied by the inner wall of the shaft hole to the claw is reduced to assist in releasing the oil seal into the mounting groove.

[0015] The outer diameter of the stepped shoulder 3 is smaller than the inner diameter of the end of the shaft hole A. When inserted, its end face abuts against the shaft hole port to limit the insertion depth of the tooling and realize the limited installation of the oil seal.

[0016] Preferably, the claw 21 is a metal elastic sheet with an inverted V-shaped cross-section. One end of each claw 21 is fixedly connected to the tooling body, while the other end is freely and elastically open and close. In addition to the inverted V-shaped cross-section, it can also be an inverted "U" shape or other structures. Any structure that can complete the clamping and releasing actions is also within the scope of protection of this patent.

[0017] Preferably, the height of the steel ring 4 is 30mm, and the axial distance between the stepped shoulder 3 and the bottom end face of the steel ring is 30mm, so as to precisely control the axial installation distance between the two oil seals at 30mm.

[0018] Preferably, the steel ring 4 is a limiting structure sleeved on the tooling body, its inner diameter matches the outer diameter of the corresponding installation part of the tooling body, and its bottom end face abuts against the edge of the shaft hole A port in the installation state to form an auxiliary limiting stop.

[0019] Preferably, the free end of the chuck 21 is a spherical or smoothly transitioned structure, which is used to reduce friction and interference during insertion into the shaft hole A and prevent the chuck structure from being lifted or deformed by the inner wall of the shaft hole.

[0020] Preferably, the tooling body further includes a hand-held section 5, located behind the bearing section 2, and the two are connected by an outer diameter difference to form a stepped shoulder 3.

[0021] In use, the internal oil seal is first installed into the mounting groove at the bottom of the shaft hole using a tool without a steel ring. Then, the external oil seal is installed into the mounting groove of the shaft hole near the outside of the oil-immersed lubrication mechanism using a tool with a steel ring, thus forming a double oil seal sealing structure with controlled spacing.

[0022] The advantages of this utility model over the prior art are as follows:

[0023] 1. By setting a stepped shoulder and a detachable steel ring on the tooling body, the installation position of the two oil seals is defined, ensuring that a precise axial distance (such as 30mm) is maintained between them, effectively ensuring the stability of the lubricating oil cavity structure and preventing a decrease in sealing performance.

[0024] 2. The use of a guide section and stepped shoulder structure improves the centering accuracy of tooling insertion, prevents the oil seal from being installed at an angle or eccentrically, and significantly improves the sealing effect and oil seal life.

[0025] 3. This utility model fixture uses jaws to clamp the oil seal. During insertion into the shaft hole, the outer edge of the oil seal held by the jaws is slightly larger than the inner diameter of the shaft hole. Under the radial compression of the inner wall of the shaft hole, the jaws gradually spring back, keeping the oil seal in a clamped state. When the oil seal reaches the preset installation groove position, the radial restriction of the inner wall of the shaft hole on the jaws weakens, and the jaws release the oil seal into the installation groove under the elastic recovery action, thereby achieving the smooth installation of the oil seal. This structure effectively avoids the problems of oil seal deformation, lip damage, or positioning misalignment caused by traditional hammering methods, improving assembly quality and installation consistency.

[0026] 4. The steel ring described in this utility model is a detachable structure. Users can flexibly replace it with a 30mm high steel ring according to different installation requirements to precisely control the axial distance between the two oil seals. The steel ring can be installed using a snap-fit, threaded locking, or other convenient mechanical connection methods to ensure the steel ring is firmly fixed to the tooling body, while facilitating quick disassembly and replacement. This design not only ensures high-precision control of the installation distance but also improves the applicability of the tooling and the flexibility of on-site adjustment. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a longitudinal cross-sectional view of the tooling body of this utility model;

[0029] Figure 2 This is a longitudinal cross-sectional view of the tooling body of this utility model after it is connected to the steel ring;

[0030] Figure 3 This is a longitudinal cross-sectional view of the present invention when the internal oil seal is installed;

[0031] Figure 4 This is a longitudinal cross-sectional view of the present invention when the external oil seal is installed;

[0032] Reference numerals: A, shaft hole; B, oil seal; 1, guide section; 2, bearing section; 21, chuck; 3, stepped shoulder; 4, steel ring; 5, hand-held section. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0035] like Figures 1-4 As shown, this embodiment provides a limiting fixture for installing oil seals in a pusher, suitable for installing two oil seals at a preset axial distance in a shaft hole A. The fixture includes:

[0036] The tooling body has a guide section 1, a bearing section 2 and a stepped shoulder 3 arranged sequentially at one end. The stepped shoulder 3 is used as the installation limit reference for oil seal B.

[0037] The outer peripheral wall of the bearing section 2 is provided with a plurality of circumferentially distributed claws 21. The claws 21 and the bearing section 2 form a clamping cavity for clamping the oil seal B. The claws 21 have a radially elastically openable structure for bending the oil seal B into a lip or petal shape so that it can enter the shaft hole A.

[0038] In a preferred embodiment, the number of claws 21 is three.

[0039] The tooling body is also provided with a positioning and limiting structure, which is a steel ring 4 that can be detachably sleeved on the outer peripheral wall of the tooling body. The top surface of the steel ring 4 abuts against the stepped shoulder 3, and the distance between the bottom surface and the stepped shoulder is a preset axial spacing, which is used to control the installation position spacing of the two oil seals B.

[0040] The outer diameter of the guide section 1 is smaller than the inner diameter of the shaft hole A, and is used to guide the tooling to align with the shaft hole and insert smoothly.

[0041] The maximum outer diameter of the bearing section 2 is not greater than the inner diameter of the shaft hole A. The outer diameter of the combined structure after the claw 21 clamps the oil seal B is greater than the inner diameter of the shaft hole A. During installation, it can radially shrink and deform under the action of external force to achieve insertion into the shaft hole. Specifically, during installation, it is squeezed by external force to form an interference fit. During the process of entering the shaft hole, the inner wall of the shaft hole applies a radial compressive force to the claw. When the oil seal reaches the mounting groove of the shaft hole A, the radial compressive force applied by the inner wall of the shaft hole to the claw is reduced to assist in releasing the oil seal into the mounting groove.

[0042] The outer diameter of the stepped shoulder 3 is smaller than the inner diameter of the end of the shaft hole A. When inserted, its end face abuts against the shaft hole port to limit the insertion depth of the tooling and realize the limited installation of the oil seal.

[0043] The claw 21 is a metal elastic sheet with an inverted V-shaped cross-section. One end of each claw 21 is fixedly connected to the tooling body, and the other end is freely and elastically open and close.

[0044] The height of the steel ring 4 is 30mm, and the axial distance between the stepped shoulder 3 and the bottom end face of the steel ring is 30mm, which is used to precisely control the axial installation distance between the two oil seals at 30mm.

[0045] The steel ring 4 is a limiting structure sleeved on the tooling body. Its inner diameter matches the outer diameter of the corresponding installation part of the tooling body. Its bottom end face abuts against the edge of the shaft hole A port in the installation state to form an auxiliary limiting stop.

[0046] The free end of the chuck 21 is spherical or has a smooth transition structure, which is used to reduce friction and interference during the insertion of the chuck into the shaft hole A and to prevent the chuck structure from being lifted or deformed by the inner wall of the shaft hole.

[0047] The tooling body also includes a hand-held section 5, located behind the bearing section 2, and the two are connected by an outer diameter difference to form a stepped shoulder 3.

[0048] This utility model's limiting fixture uses a stepped shoulder on the fixture body and a detachable steel ring to define the installation position of the oil seal, achieving precise control of the axial distance between two oil seals. The jaw structure of the fixture's bearing section uses elastic metal sheets that can open radially to clamp the oil seal. Through the elastic deformation of the jaws and the radial compression of the inner wall of the shaft hole, stable clamping and smooth release of the oil seal are achieved. The guide section ensures the alignment of the fixture with the shaft hole, preventing the oil seal from being installed tilted or eccentrically. This structural design achieves precise positioning and installation of the oil seal, avoiding installation quality problems caused by impact, misalignment, or deformation in traditional hammering installation, thus improving the sealing performance and service life of the oil seal.

[0049] The process of installing oil seal B using the tooling in this embodiment is as follows:

[0050] First, the internal oil seal B to be installed is clamped between the jaws 21 provided on the bearing section 2 of the fixture body. The jaws 21, through their elastic opening structure, make the oil seal B lip-shaped or petal-shaped, facilitating insertion into the shaft hole A. At this time, the outer edge dimension of the jaws 21 clamping the oil seal B is slightly larger than the inner diameter of the shaft hole A to ensure a stable and reliable clamping process.

[0051] Subsequently, guided by guide section 1, the entire tooling is slowly inserted into shaft hole A. Guide section 1 ensures that the tooling is coaxially aligned with shaft hole A, preventing tilting or eccentricity during insertion. Through manual operation and the thrust during insertion, the jaws 21 are radially compressed by the inner wall of shaft hole A, causing elastic deformation, which allows the clamped oil seal B to be smoothly guided into shaft hole A.

[0052] When the tooling is inserted to the predetermined depth, the end face of the stepped shoulder 3 abuts against the port of the shaft hole A, limiting the insertion depth of the tooling and thus achieving accurate positioning and installation of the oil seal B. At this time, when the internal oil seal B is inserted into the mounting groove at the bottom of the shaft hole A along with the tooling via the claw 21 of the bearing section 2, the radial clamping force of the claw 21 at this position is significantly weakened due to the radial step transition of the mounting groove relative to the inner wall of the shaft hole A, causing the edge of the clamped oil seal B to tend to release. The unclamped edge of the oil seal B first enters the mounting groove and is initially fixed by the radial limiting effect of the groove wall. Subsequently, during the gradual removal of the tooling, the oil seal B completely detaches from the tooling and is fully embedded in the mounting groove, and is finally accurately and stably installed in the predetermined position of the shaft hole A. To ensure smooth release of the oil seal within the mounting slot, the gripping position of the claw 21 when gripping the oil seal B should be designed to expose at least part of the outer edge of the oil seal. This is to prevent the claw 21 from over-covering the oil seal and to ensure that the oil seal can be smoothly released and accurately positioned after being inserted into the mounting slot.

[0053] For the installation of external oil seal B, the steel ring 4 must first be fitted onto the outer circumference of the tooling body. An axial distance (e.g., 30mm) is preset between the bottom end face of the steel ring 4 and the stepped shoulder 3 to ensure that the relative distance between the two oil seals B meets the design requirements.

[0054] Following the same steps, the external oil seal B is installed into the mounting groove near the outer side of the oil-immersed lubrication mechanism in the shaft hole A using a tool with a steel ring 4. The steel ring 4 acts as a limiting structure during installation, preventing the tool from being inserted too deeply and ensuring that the spacing between the oil seals B remains stable and precise.

[0055] After oil seal B is installed, gradually pull out the fixture to release oil seal B, ensuring that oil seal B is accurately positioned without damage. Handheld section 5 facilitates operator grip and guidance, effectively improving stability and safety during installation.

[0056] It should be noted that, to prevent lubricating oil leakage and the intrusion of external impurities, two oil seal elements are usually installed at both ends of the shaft hole. The inner oil seal is located near the inside of the equipment and is mainly used to prevent lubricating oil from leaking outwards; the outer oil seal is located at the shaft hole opening near the side of the oil-immersed lubrication mechanism, serving to prevent dust and scrape and collect oil, and guiding the returned oil to the return oil groove. A closed cavity is formed between the two oil seals for oil storage and return. Since the outer oil seal is located on the outermost side, its installation position is axially upward and outward, and the corresponding shaft hole diameter is usually larger than the installation section of the inner oil seal. Therefore, during assembly, the inner oil seal can be inserted deep into the shaft hole first, avoiding the installation position of the outer oil seal, thus achieving step-by-step assembly and avoiding mutual interference.

[0057] Of course, the above description is not intended to limit the present utility model, nor is the present utility model limited to the examples given above. Any changes, alterations, additions or substitutions made by those skilled in the art within the scope of the present utility model should be protected by the present utility model.

Claims

1. A limiting fixture for installing oil seals in a pusher, suitable for installing two oil seals at a preset axial distance in a shaft hole (A), characterized in that, The tooling includes: The tool body has a guide section (1), a bearing section (2) and a stepped shoulder (3) in sequence at one end. The stepped shoulder (3) is used as the installation limit reference for the oil seal (B). The outer peripheral wall of the bearing section (2) is provided with a plurality of circumferentially distributed claws (21). The claws (21) and the bearing section (2) form a clamping cavity for clamping the oil seal (B). The claws (21) have a radially elastically openable structure for bending the oil seal (B) into a lip or petal shape so that it can enter the shaft hole (A). The tooling body is also provided with a positioning and limiting structure. The positioning and limiting structure is a steel ring (4) that can be detachably sleeved on the outer peripheral wall of the tooling body. The top surface of the steel ring (4) abuts against the stepped shoulder (3), and the distance between the bottom surface and the stepped shoulder is a preset axial spacing, which is used to control the installation position spacing of the two oil seals (B).

2. The limiting fixture for oil seal installation according to claim 1, characterized in that, The outer diameter of the guide section (1) is smaller than the inner diameter of the shaft hole (A), which is used to guide the tooling to align with the shaft hole and insert smoothly; The maximum outer diameter of the bearing section (2) is not greater than the inner diameter of the shaft hole (A). The outer diameter of the combined structure after the claw (21) clamps the oil seal (B) is greater than the inner diameter of the shaft hole (A). During the installation process, it can radially shrink and deform under the action of external force to achieve insertion into the shaft hole. The outer diameter of the stepped shoulder (3) is smaller than the inner diameter of the end of the shaft hole (A). When inserted, its end face abuts against the shaft hole port to limit the insertion depth of the tooling and realize the limited installation of the oil seal.

3. The limiting fixture for oil seal installation according to claim 1, characterized in that, The claw (21) is a metal elastic sheet with an inverted V-shaped cross section. One end of each claw (32) is fixedly connected to the tooling body, and the other end is freely and elastically open and close.

4. The limiting fixture for oil seal installation according to claim 1, characterized in that, The height of the steel ring (4) is 30mm, and the axial distance between the stepped shoulder (3) and the bottom end face of the steel ring is 30mm, which is used to precisely control the axial installation distance between the two oil seals to 30mm.

5. The limiting fixture for oil seal installation according to claim 1, characterized in that, The steel ring (4) is a limiting structure sleeved on the tooling body. Its inner diameter matches the outer diameter of the corresponding installation part of the tooling body. Its bottom end face abuts against the edge of the shaft hole (A) port in the installation state to form an auxiliary limiting stop.

6. The limiting fixture for oil seal installation according to claim 1, characterized in that, The free end of the claw (21) is spherical or has a smooth transition structure to reduce friction and interference during insertion into the shaft hole (A).

7. The limiting fixture for oil seal installation according to claim 1, characterized in that, The tooling body also includes a hand-held section (5), located behind the bearing section (2), and the two are connected by an outer diameter difference to form a stepped shoulder (3).

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