Sleeve forging and ring rolling tool and method for conical bearing

Abstract

The invention relates to the technical field of conical bearing sleeve forging machining, in particular to a sleeve forging ring rolling tool and method for a conical bearing. Comprising a rolling wheel and a core roller matched with the rolling wheel, and the rolling wheel and the core roller are matched to form a rolling cavity. An L-shaped cavity is formed in the outer wall of the rolling wheel, the core roller comprises a conical section matched with the cavity, a transverse part of the L-shaped cavity is arranged in an inclined mode, and the inclined direction of the transverse part of the L-shaped cavity is opposite to the inclined direction of the conical section. Through the structural innovation of the small-taper core roller cooperating with the reversely-inclined L-shaped cavity and the process optimization of bidirectional cooperative feeding, efficient, high-precision and low-cost manufacturing of the conical bearing ring is achieved, the service life of the tool is effectively prolonged, the comprehensive performance index is remarkably superior to that of a traditional ring rolling process, and the production efficiency is improved. And the method is particularly suitable for large-scale production of high-end bearings.

Description

Technical Field

[0001] The invention relates to the technical field of sleeve forging processing of tapered bearings, and in particular to a sleeve forging and rolling tool and method for tapered bearings. Background Art

[0002] Forging and rolling technology for tapered bearing sleeves is an important process in the field of precision machinery manufacturing. Traditional processes mainly use forging combined with turning or one-way rolling. Although these methods are mature, they have obvious technical bottlenecks.

[0003] like Figure 5 As shown in the figure, in terms of tooling structure, the existing technology generally adopts a large-taper core roller design, which leads to excessive radial force, severe stress concentration and easy breakage, and the mold life is usually less than 30,000 times; a matching U-shaped groove structure is provided on the outer wall of the rolling wheel, and the transverse part of the L-shaped cavity of the rolling wheel is mostly horizontally designed, which has poor metal flow control ability and causes excessive subsequent processing allowance.

[0004] In addition, the large-taper core roller is designed with the large-diameter end facing outward. At this time, in the previous process, the aperture of the forging punching is required to be larger, that is, a larger aperture can be placed on the core roller, which increases the difficulty of the previous process. The large-diameter punching requires a larger tonnage press or a more complex mold structure, and the equipment investment cost increases significantly.

[0005] Furthermore, if Figure 5 As shown, during the rolling process, the core roller and the rolling wheel cooperate to form a closed cavity. Both ends of the material are in contact with the working surface of the rolling wheel. The rolling wheel is subject to significant wear and tear, requiring frequent downtime for replacement or grinding. This is because the working surface profile of the rolling wheel changes as it wears, resulting in uneven wall thickness of the material. Furthermore, hard particles produced by wear on the rolling wheel surface may embed into the material surface, forming a source of microcracks. During subsequent heat treatment or service, these defects may expand into macrocracks, leading to premature product failure, reduced yield, and increased service risks.

[0006] In terms of process efficiency, the uneven metal flow during unidirectional rolling requires three to four passes, taking up to 30-40 seconds per piece. Furthermore, controlling the temperature window is difficult, which can easily lead to quality issues such as coarse grains and work hardening. More prominent is the issue of product qualification rate. Conventional processes achieve a porosity expansion rate as high as 12-15%, inner hole roundness errors exceeding 0.1mm, and contact angle deviations of ±1.5°, severely limiting the performance of high-end bearings. Regarding economic efficiency, rapid mold wear and tear results in 15% of downtime, collectively constraining the industry's development. While existing patented technologies attempt to mitigate these issues through limited improvements such as core roller cooling, multi-stage rolling wheels, or hydraulic control, none have fundamentally resolved the core technical conflict between metal flow control and mold life. With the increasing performance requirements for bearings in industries such as automotive and wind power, developing a new sleeve forging and rolling technology that simultaneously meets the requirements for high precision, high efficiency, and a high qualification rate (>95%) has become a critical technical bottleneck that needs to be overcome. Summary of the Invention

[0007] The present invention provides a sleeve forging and rolling tool and method for a tapered bearing, so as to solve the technical problems in the prior art of short service life of the rolling tool and high expansion rate of the hole through the rolling process of the tool.

[0008] To solve the above problems, the present invention provides a tool and method for forging and expanding a tapered bearing, which adopts the following technical solutions: A sleeve forging and rolling tool for a tapered bearing comprises a rolling wheel and a core roller matched with the rolling wheel. The rolling wheel and the core roller cooperate to form a rolling cavity.

[0009] An L-shaped cavity is formed on the outer wall of the rolling wheel, and the core roller includes a tapered section that matches the cavity. The transverse portion of the L-shaped cavity is tilted and the tilt direction is opposite to the tilt direction of the tapered section.

[0010] When the rolling wheel and the core roller cooperate to perform rolling, an open rolling cavity is formed between the L-shaped cavity and the core roller.

[0011] Furthermore, the vertical portion of the L-shaped cavity is perpendicular to the horizontal portion.

[0012] Furthermore, a chamfer with a radius of 2.5 mm is formed at the joint between the vertical portion and the horizontal portion of the L-shaped cavity.

[0013] Furthermore, the angle between the hypotenuse formed by the tapered section on the core roller and the axis of the core roller is α, and 3°≤α≤5°.

[0014] Furthermore, the angle between the transverse portion of the L-shaped cavity and the axis of the core roller is β, and the angle between the hypotenuse formed by the inner ring of the finished jacket and the central axis is γ, wherein γ=α+β.

[0015] A method for forging and rolling a tapered bearing is provided, wherein the method is implemented using the above-mentioned tooling for forging and rolling a tapered bearing, and comprises the following steps: The sleeve material to be rolled is placed on the core roller, the rolling wheel is fed gradually downward along the radial direction of the core roller and the core roller is fed gradually along its axial direction, and the sleeve forging and rolling are completed through the synchronous action of the inner ring and the outer ring.

[0016] Furthermore, the feeding speed of the rolling wheel is 1.0-2.5 mm / s.

[0017] Furthermore, the feeding speed of the core roller is 0.3-0.8 mm / s.

[0018] Furthermore, when the jacketing is rolled, the initial forging temperature is ensured to be 1050°C-1150°C and the final forging temperature is ensured to be 800°C-850°C.

[0019] The beneficial effects of the sleeve forging and rolling tool and method for tapered bearings provided by the present invention are: 1. In this invention, the transverse portion of the L-shaped cavity and the tapered section of the core roller are designed with opposite inclinations. Through precise matching, this achieves combined radial and axial plastic flow, saving over 30% of labor hours. Metal flow is bidirectionally guided by the rolling wheel and core roller, resulting in balanced radial and axial deformation, improved wall thickness uniformity by approximately 30%, and reduced porosity from 12% to below 5%.

[0020] Specifically, the matching relationship of γ=α+β ensures that the direction of metal flow is consistent with the geometric requirements of the finished product. The metal flow is more uniform and the inner hole is prevented from expanding due to excessive pressure on one side.

[0021] 2. In the present invention, the tapered section on the core roller only bears a small angle, which greatly reduces the radial shear force, reduces the peak stress of the core roller, and transfers the maximum stress point from the root to the middle, effectively reducing fatigue cracks and easy fracture, and greatly improving the service life; Furthermore, the tapered section on the core roller is designed with the smaller diameter end facing outward. This allows for the pre-punching process of the expanded nesting material, which is then placed on the core roller, to reduce the need for large diameter holes. This reduces the difficulty of the pre-punching process, the required punching force, and the requirements for mold strength and equipment tonnage. This not only reduces equipment investment costs, but also reduces the risk of mold wear and breakage caused by large-diameter punching, thereby improving process stability.

[0022] During the rolling process, a smaller initial pore size can make the material deform more uniformly and reduce the Defects such as cracks and wrinkles caused by excessive shape.

[0023] 3. In the present invention, during the rolling process, one end of the rolling cavity formed by the L-shaped cavity and the core roller is open to the outside. At this time, during the rolling process, there is no contact between one end of the sleeve and the rolling wheel, that is, there is no friction, and the contact area is reduced by 30%-40%, which effectively reduces the wear on the working surface of the rolling wheel and significantly improves the service life of the tooling.

[0024] 4. In the process of the present invention, at the initial forging temperature of 1050°C-1150°C, the plasticity of the bearing steel is excellent. The coordinated feed rate of the rolling wheel and the core roller can avoid micro cracks caused by excessive strain rate. The coordinated coordination of the specific feed rate achieves balanced axial and radial flow and makes the wall thickness more uniform. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other objects, features and advantages of the exemplary embodiments of the present invention will become readily understood by reading the following detailed description with reference to the accompanying drawings. In the accompanying drawings, several embodiments of the present invention are shown in an illustrative and non-limiting manner, and the same or corresponding reference numerals represent the same or corresponding parts, wherein: Figure 1 This is a schematic diagram of the use state of the sleeve forging and rolling tool of the tapered bearing of the present invention; Figure 2 is a cross-sectional view of the core shaft of the present invention; Figure 3 It is a partial cross-sectional view of the rolling wheel in the present invention; Figure 4 It is a cross-sectional view of the finished nesting material in the present invention; Figure 5 It is a schematic diagram of the processing state in the prior art; Figure 6 This is a flow chart of the overall processing steps of the outer ring of the bearing sleeve in this embodiment.

[0026] Description of reference numerals: 1. Rolling wheel; 11. L-shaped cavity; 111. Horizontal portion; 112. Vertical portion; 2. Mandrel; 21. Conical section; 3. Rolling cavity. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Those skilled in the art should know that the embodiments described below are part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0028] Any number of elements in the drawings is for illustration and not limitation, and any naming is for distinction only and does not have any limiting meaning.

[0029] The principles and spirit of the present invention are explained in detail below with reference to several representative embodiments of the present invention.

[0030] An embodiment of a sleeve forging and rolling tool for a tapered bearing provided by the present invention: like Figures 1 to 4 As shown, The invention comprises a rolling wheel 1 and a core roller 2 matched with the rolling wheel 1 , wherein the rolling wheel 1 and the core roller 2 cooperate to form a rolling cavity 3 .

[0031] The outer wall of the rolling wheel 1 is formed with an L-shaped cavity 11, and the core roller 2 includes a tapered section 21 that cooperates with the L-shaped cavity 11. The transverse portion 111 of the L-shaped cavity 11 is tilted and the tilt direction is opposite to the tilt direction of the tapered section 21.

[0032] The vertical portion 112 of the L-shaped cavity 11 is perpendicular to the horizontal portion 111 .

[0033] The joint between the vertical portion 112 and the horizontal portion 111 of the L-shaped cavity 11 is formed with a rounded corner with a radius of 2.5 mm.

[0034] In this embodiment, the angle between the hypotenuse formed by the tapered section 21 on the core roller 2 and the axis of the core roller 2 is α, and α is 3°.

[0035] Among them, the conical section 21 on the core roller 2 only bears a small angle, which greatly reduces the radial cutting force, reduces the peak stress of the core roller 2, and transfers the maximum stress point from the root to the middle, effectively reducing fatigue cracks and easy breakage, and greatly improving the service life.

[0036] In addition, the tapered section 21 on the core roller 2 has a smaller diameter at the end facing outward. When the expanded nesting material is placed on the core roller 2, the punching process in the nesting section does not require a large diameter. This reduces the difficulty of the previous process, the punching force required, and the requirements for mold strength and equipment tonnage. This not only reduces equipment investment costs, but also reduces the risk of mold wear and breakage caused by large-diameter punching, thereby improving process stability.

[0037] During the rolling process, a smaller initial pore size can make the material deform more uniformly and reduce defects such as cracks and wrinkles caused by excessive local deformation.

[0038] The included angle between the transverse portion 111 of the L-shaped cavity 11 and the axis of the core roller 2 is β, and the included angle γ between the hypotenuse formed by the inner ring of the finished nesting material and the central axis is 16°, where γ=α+β.

[0039] The present invention's rolling fixture features an inversely inclined design between the transverse portion 111 of the L-shaped cavity 11 and the tapered core roller section 21. This geometric interference generates composite radial and axial plastic flow. When γ = α + β, the bevel angle of the finished inner ring precisely matches the bearing contact angle requirement, eliminating secondary machining.

[0040] The β inclination angle of the transverse portion 111 of the L-shaped cavity 11 guides the metal flow in the axial direction and reduces radial accumulation. The reverse inclination angle α of the tapered section 21 on the core roller 2 provides reverse constraint, ensuring balanced expansion of the metal in both radial and axial directions and preventing localized excessive deformation.

[0041] The matching relationship of γ=α+β ensures that the direction of metal flow is consistent with the geometric requirements of the finished product, reduces unnecessary radial expansion, and ultimately achieves more uniform metal flow, avoiding the expansion of the inner hole due to excessive pressure on one side.

[0042] In this embodiment, when the rolling wheel 1 and the core roller 2 cooperate to perform rolling, an open rolling cavity 3 is formed between the L-shaped cavity 11 and the core roller 2 .

[0043] Specifically, such as Figure 1 As shown, during the rolling process, the right end of the rolling cavity 3 formed by the L-shaped cavity 11 and the core roller 2 is open to the outside. At this time, during the rolling process, there is no contact between the right end of the sleeve and the rolling wheel 1, that is, there is no friction, and the contact area is reduced by 30%-40%, which effectively reduces the wear on the working surface of the rolling wheel 1 and significantly improves the service life of the tooling.

[0044] A method for forging and rolling a tapered bearing is provided, wherein the method is implemented using the above-mentioned tooling for forging and rolling a tapered bearing, and comprises the following steps: The sleeve material to be rolled is placed on the core roller 2, and the rolling wheel 1 is fed downward step by step along the radial direction of the core roller 2 and the core roller 2 is fed forward step by step along its axial direction, and the sleeve forging and rolling are completed through the synchronous action of the inner ring and the outer ring.

[0045] Specifically, the outer ring of the bearing is processed by this process, such as Figure 6 , which is the overall processing procedure, and the rolling operation is carried out after flattening.

[0046] Traditional processes use only radial feed with a rolling wheel, resulting in slow metal flow and requiring multiple reciprocating rolls to achieve the target dimensions, resulting in a long production time per piece. Furthermore, axial deformation relies on the metal's natural extension, which can easily lead to insufficient mold filling and require subsequent shaping.

[0047] In the process of this embodiment, the metal is actively stretched axially while expanding radially, thereby improving deformation efficiency.

[0048] The feeding speed of the rolling wheel 1 is 1.0-2.5 mm / s.

[0049] Wherein, the feeding speed of the core roller 2 is 0.3-0.8 mm / s.

[0050] Among them, when the nesting material is rolled, the initial forging temperature is guaranteed to be 1050℃-1150℃, and the final forging temperature is guaranteed to be 800℃-850℃.

[0051] Specifically, in a high temperature environment of 1050°C-1150°C, the plasticity of the bearing steel is good, and the micro cracks caused by excessively high strain rate can be avoided through the coordinated feeding progress of the rolling wheel 1 and the core roller 2.

[0052] It should be noted that the aforementioned coordinated feed speeds achieve balanced axial and radial flow and a more uniform wall thickness. When the feed speed of the rolling wheel 1 is fast and the feed speed of the core roller 2 is slow, insufficient axial flow will occur, ultimately leading to radial expansion holes and localized stress concentration on the core roller 2. When the feed speed of the rolling wheel 1 is slow and the feed speed of the core roller 2 is fast, excessive axial stretching is likely to occur.

[0053] According to the above description of this specification, those skilled in the art may also understand that the terms used below, such as "up", "down", "front", "back", "left", "right", "width", "horizontal", "top", "bottom", "inside", "outside" and other terms indicating orientation or positional relationships are based on the orientation or positional relationships shown in the drawings of this specification. They are only for the purpose of facilitating the explanation of the scheme of the present invention and simplifying the description, rather than explicitly or implicitly indicating that the devices or elements involved must have the specific orientation, be constructed and operated in a specific orientation. Therefore, the above-mentioned orientation or positional relationship terms cannot be understood or interpreted as limitations on the scheme of the present invention.

[0054] In addition, in the description of this specification, “a plurality of” means at least two, for example, two, three or more, etc., unless otherwise clearly and specifically defined.

Claims

1. A forging and rolling tool for a tapered bearing, comprising a rolling wheel (1) and a core roller (2) cooperating with the rolling wheel (1). It is characterized by: The rolling wheel (1) and the core roller (2) cooperate to form a rolling cavity (3); The outer wall of the rolling wheel (1) is formed with an L-shaped cavity (11), and the core roller (2) includes a The tapered section (21) of the L-shaped cavity (11) is provided with a transverse portion (111) that is inclined and has an inclination direction opposite to that of the tapered section (21); When the rolling wheel (1) and the core roller (2) cooperate to perform rolling, the L-shaped cavity (11) and the core roller (2) cooperate to form a The expanded cavity (3) is formed into an open type.

2. The forging and rolling tool for tapered bearings according to claim 1, characterized in that: The vertical L-shaped cavity (11) The lateral portion (112) is perpendicular to the lateral portion (111).

3. The sleeve forging and rolling tool for tapered bearings according to claim 2, characterized in that: The vertical L-shaped cavity (11) A chamfer with a radius of 2.5 mm is formed at the joint between the forward portion (112) and the transverse portion (111).

4. The forging and rolling tool for tapered bearings according to claim 1, characterized in that: The core roller (2) is tapered The angle between the oblique side formed by the segment (21) and the axis of the core roller (2) is α, and 3°≤α≤5°.

5. The sleeve forging and rolling tool for tapered bearings according to claim 4, characterized in that: The L-shaped cavity (11) has a horizontal The included angle between the axial line of the axial portion (111) and the core roller (2) is β, and the included angle between the hypotenuse formed by the inner ring of the finished sleeve and the central axis is γ, wherein γ=α+β.

6. A method for sleeve forging and rolling of a tapered bearing, characterized in that: The rolling method adopts any one of claims 1 to 5 The above-mentioned sleeve forging and rolling tooling of the tapered bearing is realized, comprising the following steps: The sleeve material to be rolled is placed on the core roller (2), the rolling wheel (1) is fed gradually downward along the radial direction of the core roller (2), and the core roller (2) is fed gradually along its axial direction, and the sleeve forging and rolling are completed through the synchronous action of the inner ring and the outer ring.

7. The sleeve forging and rolling method of a tapered bearing according to claim 6, characterized in that: The rolling wheel (1) The feed speed is 1.0-2.5mm / s.

8. The sleeve forging and rolling method of a tapered bearing according to claim 7, characterized in that: The feeding of the core roller (2) The speed is 0.3-0.8mm / s.

9. The sleeve forging and rolling method of a tapered bearing according to claim 6, characterized in that: When the nesting material is rolled, the initial forging temperature is guaranteed to be 1050℃-1150℃ and the final forging temperature is 800℃-850℃.

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