Assembling method of large-scale full-complement CARB bearing

Abstract

The invention belongs to the technical field of bearing assembly, and discloses an assembly method of a large full complement CARB bearing. The method comprises the following steps: firstly, establishing full complement CARB bearing geometric surface modeling; and carrying out mathematical modeling and analysis in the assembling process. A motion reversal principle is innovatively adopted, an assembly process is converted into a disassembly inverse motion, a coordinate transformation matrix under a roller axial deviation angle is constructed, and roller-outer ring contact constraint and inner ring relative motion are accurately described. By calculating the spatial distance between the curvature center coordinate of the inner raceway after offset and the assembly judgment base point, the radial clearance equivalent condition is creatively put forward to serve as the assembly feasibility criterion. According to the method, the minimum assembly deviation angle can be quantitatively solved, the efficiency of a full complement bearing assembly process is remarkably improved, and theoretical support is provided for digital assembly of a high-density rolling bearing.

Description

Technical Field

[0001] This invention belongs to the field of bearing assembly technology and relates to an assembly method for a large full complement CARB bearing. Background Technology

[0002] In a complex industrial transmission system, shafts inevitably experience slight bending or misalignment due to load or thermal expansion and contraction. Ordinary cylindrical roller bearings cannot tolerate such deviations, while traditional self-aligning roller bearings, although capable of self-alignment, have limitations in load-bearing capacity. The emergence of CARB bearings provides a unique solution in this context. The core of CARB is its unique single-row symmetrical barrel rollers, which not only rotate to bear the load but also easily slide axially along the inner ring raceway when needed. This is distinctly different from the double-row asymmetrical roller structure of traditional self-aligning bearings and is the physical basis for achieving its key characteristics.

[0003] Currently, there are several main assembly methods for CARB bearings: Press fitting: Pressure is applied only to the outer ring, pressing it into the bearing housing bore. A special press fitting sleeve is used to ensure that the pressure is applied evenly to the end face of the outer ring, and pressure must not be applied to the inner ring. Heat fitting (outer ring heating): The entire outer ring of the bearing is uniformly heated to a specified temperature to achieve the required expansion. Press fitting requires precise installation equipment to strictly ensure requirements such as fit tolerances and assembly perpendicularity. Heat fitting is not suitable for bearings of all sizes and seals. For large CARB bearings, heating may cause permanent deformation or failure of the seals, therefore heat fitting is generally not suitable. Summary of the Invention

[0004] To address the shortcomings of existing assembly methods and overcome the limitations of heat fitting and press fitting methods for bearings of all sizes and seals, as well as their high cost, this invention provides a mathematical model and assembly path for bearing assembly to solve the difficult assembly problem of large full complement roller CARB bearings.

[0005] The technical solution of this invention:

[0006] An assembly method for a large full complement CARB bearing, comprising the following steps:

[0007] (1) Modeling the geometric surface of a full-load CARB bearing;

[0008] Establish a Cartesian coordinate system for the outer ring of a full-load CARB bearing. Let be the coordinate system of the outer circle; the center of the outer circle is the origin. The axial direction of the outer ring is The radial direction of the outer ring of the shaft is... shaft and axis;

[0009] Coordinates of any point on the outer raceway The surface equation of the outer raceway satisfies the following equations:

[0010]

[0011] in, Let be the radius of the highest point of the outer raceway groove; the surface equation of the outer raceway describes the surface of the outer raceway, and its cross-section has a radius of . The arc;

[0012] Establish a Cartesian coordinate system for the inner ring of a full-load CARB bearing. Let be the coordinate system of the inner circle; the center of the inner circle is the origin. The axial direction of the inner ring is The radial direction of the inner ring of the shaft is... shaft and axis;

[0013] Coordinates of any point on the inner raceway The surface equation of the inner raceway satisfies the following equations:

[0014]

[0015] in, Let be the radius of the lowest point of the inner raceway groove; the surface equation of the inner raceway describes the surface of the inner raceway, and its cross-section has a radius of . The arc;

[0016] Establish a Cartesian coordinate system for the rollers of a full-load CARB bearing Let be the coordinate system of the roller; the center of the roller is the origin. The axial direction of the roller is The radial direction of the shaft and rollers is shaft and axis;

[0017] coordinates of any point on the roller The surface equation of the roller satisfies the following equations:

[0018]

[0019] in, Let be the roller radius; the surface equation of the roller describes the roller surface, and its cross-section has a radius of . The arc;

[0020] (2) Mathematical modeling and analysis of the assembly process;

[0021] A mathematical model of the assembly process of a fully loaded CARB bearing is established using the inversion method, that is, the bearing assembly process is regarded as the reverse process of disassembling the bearing.

[0022] In the actual assembly process, the outer ring is in a fixed position, and the rollers and inner ring are installed into the outer ring. The mathematical model of the assembly process of a full complement CARB bearing is as follows: First, the coordinates of the outer ring, inner ring, and rollers are represented in the coordinate systems of the outer ring, inner ring, and rollers, respectively. Then, the coordinates of the inner ring and rollers are transformed to the coordinate system of the outer ring through a pose transformation method. The coordinate system of the outer ring is taken as the generalized Cartesian coordinate system, and the coordinate systems of the inner ring and rollers are taken as local coordinate systems.

[0023] 1) Initial state and coordinate transformation:

[0024] In the coordinate system of the outer ring, rollers are sequentially loaded along the circumferential direction of the outer ring raceway. Under the influence of gravity, the loaded rollers gather at the bottom region of the outer ring raceway. The coordinates of the center position of the first loaded roller, i.e., the origin of the roller's coordinate system, are defined as follows at the initial moment:

[0025]

[0026] 2) Roller offset motion:

[0027] During assembly, the roller needs to move axially around the tangent of the contact point of the outer raceway while ensuring that the roller surface remains in contact with the raceway surface. The offset angle is... During the offset motion, the constraint roller maintains constant contact with the outer raceway surface; the homogeneous transformation matrix of the roller's coordinate system relative to the outer raceway coordinate system is:

[0028] [ 1 0 0 0 0 cos θ − sin θ − cos θ ( R outside + r g ) 0 sin θ cos θ − sin θ ( R outside + r g ) 0 0 0 1 ]

[0029] 3) Relative motion of the inner circles:

[0030] The inner ring moves synchronously relative to the coordinate system of the roller, with an offset angle of . The homogeneous transformation matrix of the inner ring coordinate system relative to the roller coordinate system for this offset motion is:

[0031] [ 1 0 0 0 0 cos θ − sin θ cos θ ( R inside + r g ) 0 sin θ cos θ sin θ ( R inside + r g ) 0 0 0 1 ]

[0032] 4) Position of the center of curvature of the inner raceway after offset:

[0033] Offset Angle Afterwards, the center of curvature of the inner raceway The coordinates in the outer coordinate system are obtained through cascaded transformations:

[0034] ( x 3 y 3 z 3 1 ) = [ 1 0 0 0 0 cos θ − sin θ − cos( R outside + r g ) 0 sin θ cos θ − sin( R outside + r g ) 0 0 0 1 ]

[0035] 5) Assembly feasibility criteria:

[0036] The constraint during assembly is: when the inner ring is offset to an angle... At that time, there must be a radius greater than the roller radius. The space allows the next roller to be inserted radially along the inner raceway surface; a radial clearance greater than the roller diameter is equivalent to calculating the distance from the center of curvature of the inner raceway to a reference point on the roller surface. The reference point is assembly judgment base point P;

[0037] The position of assembly judgment base point P needs to be determined based on the roller geometry and assembly path, and its coordinates are expressed as follows:

[0038]

[0039] in, The radius is the point where the outer raceway intersects with both ends of the bearing.

[0040] distance The calculation formula is:

[0041]

[0042] Assembly is complete when the geometric relationships satisfy the following formula. .

[0043] The beneficial effects of this invention are as follows: This invention addresses the assembly process of large full complement CARB bearings by providing mathematical equations for the raceway and roller surfaces. It utilizes a homogeneous transformation matrix to accurately describe the positional relationship between the roller offset motion and the inner ring synchronous offset motion. By analyzing the spatial positional relationship between the inner ring raceway curvature center and the roller reference point under different offset angles, this invention can obtain the optimal assembly angle and assembly path that meet radial clearance requirements, providing a reasonable and repeatable assembly process for large full complement CARB bearings. Compared with traditional press-fitting and heat-fitting methods, this invention can complete assembly at room temperature, without relying on high-precision press-fitting equipment and strict assembly perpendicularity requirements. It also avoids the problem of permanent deformation or failure of seals caused by heating the entire large sealed bearing, thus significantly reducing assembly difficulty and equipment investment, and reducing assembly costs. Furthermore, the geometric modeling method, homogeneous transformation modeling approach, and assembly feasibility criteria proposed in this invention have good versatility and can be adjusted according to different specifications and structural parameters, providing a unified theoretical basis and quantitative analysis tool for the assembly process design, structural optimization, and parameter selection of various large full complement CARB bearings. Attached Figure Description

[0044] Figure 1 These are the external dimensions of the CARB bearing.

[0045] Figure 2It is the generalized coordinate system of the CARB bearing.

[0046] Figure 3 This is the local coordinate system of the inner ring of the CARB bearing.

[0047] Figure 4 It is the local coordinate system of the CARB bearing rollers.

[0048] Figure 5 This is a schematic diagram of the inner coordinate system transformation.

[0049] Figure 6 This is a schematic diagram of the assembly base points.

[0050] Figure 7 This is a schematic diagram of the actual assembly.

[0051] Figure 8 This involves creating a flowchart of the bearing structure. Detailed implementation method.

[0052] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and technical solutions.

[0053] An assembly method for a large full complement CARB bearing, comprising the following steps:

[0054] (1) Modeling the geometric surface of a full-load CARB bearing;

[0055] Establish a Cartesian coordinate system for the outer ring of a full-load CARB bearing. Let be the coordinate system of the outer circle; the center of the outer circle is the origin. The axial direction of the outer ring is The radial direction of the outer ring of the shaft is... shaft and axis;

[0056] Coordinates of any point on the outer raceway The surface equation of the outer raceway satisfies the following equations:

[0057]

[0058] in, Let be the radius of the highest point of the outer raceway groove; the surface equation of the outer raceway describes the surface of the outer raceway, and its cross-section has a radius of . The arc;

[0059] Establish a Cartesian coordinate system for the inner ring of a full-load CARB bearing. Let be the coordinate system of the inner circle; the center of the inner circle is the origin. The axial direction of the inner ring is The radial direction of the inner ring of the shaft is... shaft and axis;

[0060] Coordinates of any point on the inner raceway The surface equation of the inner raceway satisfies the following equations:

[0061]

[0062] in, Let be the radius of the lowest point of the inner raceway groove; the surface equation of the inner raceway describes the surface of the inner raceway, and its cross-section has a radius of . The arc;

[0063] Establish a Cartesian coordinate system for the rollers of a full-load CARB bearing Let be the coordinate system of the roller; the center of the roller is the origin. The axial direction of the roller is The radial direction of the shaft and rollers is shaft and axis;

[0064] coordinates of any point on the roller The surface equation of the roller satisfies the following equations:

[0065]

[0066] in, Let be the roller radius; the surface equation of the roller describes the roller surface, and its cross-section has a radius of . The arc;

[0067] (2) Mathematical modeling and analysis of the assembly process;

[0068] A mathematical model of the assembly process of a fully loaded CARB bearing is established using the inversion method, that is, the bearing assembly process is regarded as the reverse process of disassembling the bearing.

[0069] In the actual assembly process, the outer ring is in a fixed position, and the rollers and inner ring are installed into the outer ring. The mathematical model of the assembly process of a full complement CARB bearing is as follows: First, the coordinates of the outer ring, inner ring, and rollers are represented in the coordinate systems of the outer ring, inner ring, and rollers, respectively. Then, the coordinates of the inner ring and rollers are transformed to the coordinate system of the outer ring through a pose transformation method. The coordinate system of the outer ring is taken as the generalized Cartesian coordinate system, and the coordinate systems of the inner ring and rollers are taken as local coordinate systems.

[0070] 1) Initial state and coordinate transformation:

[0071] In the coordinate system of the outer ring, rollers are sequentially loaded along the circumferential direction of the outer ring raceway. Under the influence of gravity, the loaded rollers gather at the bottom region of the outer ring raceway. The coordinates of the center position of the first loaded roller, i.e., the origin of the roller's coordinate system, are defined as follows at the initial moment:

[0072]

[0073] 2) Roller offset motion:

[0074] During assembly, the roller needs to move axially around the tangent of the contact point of the outer raceway while ensuring that the roller surface remains in contact with the raceway surface. The offset angle is... During the offset motion, the constraint roller maintains constant contact with the outer raceway surface; the homogeneous transformation matrix of the roller's coordinate system relative to the outer raceway coordinate system is:

[0075] [ 1 0 0 0 0 cos θ − sin θ − cos θ ( R outside + r g ) 0 sin θ cos θ − sin θ ( R outside + r g ) 0 0 0 1 ]

[0076] 3) Relative motion of the inner circles:

[0077] The inner ring moves synchronously relative to the coordinate system of the roller, with an offset angle of . The homogeneous transformation matrix of the inner ring coordinate system relative to the roller coordinate system for this offset motion is:

[0078] [ 1 0 0 0 0 cos θ − sin θ cos θ ( R inside + r g ) 0 sin θ cos θ sin θ ( R inside + r g ) 0 0 0 1 ]

[0079] 4) Position of the center of curvature of the inner raceway after offset:

[0080] Offset Angle Afterwards, the center of curvature of the inner raceway The coordinates in the outer coordinate system are obtained through cascaded transformations:

[0081] ( x 3 y 3 z 3 1 ) = [ 1 0 0 0 0 cos θ − sin θ − cos( R outside + r g ) 0 sin θ cos θ − sin( R outside + r g ) 0 0 0 1 ]

[0082] 5) Assembly feasibility criteria:

[0083] The constraint during assembly is: when the inner ring is offset to an angle... At that time, there must be a radius greater than the roller radius. The space allows the next roller to be inserted radially along the inner raceway surface; a radial clearance greater than the roller diameter is equivalent to calculating the distance from the center of curvature of the inner raceway to a reference point on the roller surface. The reference point is assembly judgment base point P;

[0084] The position of assembly judgment base point P needs to be determined based on the roller geometry and assembly path, and its coordinates are expressed as follows:

[0085]

[0086] in, The radius is the point where the outer raceway intersects with both ends of the bearing.

[0087] distance The calculation formula is:

[0088]

[0089] Assembly is complete when the geometric relationships satisfy the following formula.

[0090]

[0091] To verify the feasibility and applicability of the large full-load CARB bearing assembly method of the present invention, a full-load CARB bearing for a large wind turbine main shaft is used as an example for illustration. This bearing has a sealed structure, an outer diameter of approximately 850 mm, an inner diameter of approximately 600 mm, a bearing width of approximately 230 mm, 36 rollers, and a roller diameter of 24 mm.

[0092] Substituting the geometric parameters of the specific bearings mentioned above into the equations of the outer ring raceway, inner ring raceway, and roller surface, and combining this with the homogeneous transformation matrices of the roller offset motion and the inner ring synchronous offset motion, the offset angle is... Numerical calculations were performed within the specified range. The calculation results show that when the roller offset angle... Inner ring offset angle At that time, the calculation yielded At this point, there is sufficient radial clearance, allowing the next roller to be inserted radially along the inner raceway. Assembly is feasible, and the actual assembly is as follows: Figure 7 As shown.

[0093] Therefore, under the bearing structural parameters given in this embodiment, the method of the present invention can directly provide the offset angle range that satisfies the assembly criteria and the optimal combination of assembly angles through a mathematical model, avoiding the need for repeated trial assembly based on experience. This example verifies the correctness of the assembly model and assembly feasibility criteria of the present invention, proving that the method of the present invention can be used to guide the assembly process design and assembly path optimization of specific large full complement CARB bearings.

Claims

1. A method for assembling a large full complement CARB bearing, characterized in that, The steps are as follows: (1) Modeling the geometric surface of a full-load CARB bearing; Establish a Cartesian coordinate system for the outer ring of a full-load CARB bearing. Let be the coordinate system of the outer circle; the center of the outer circle is the origin. The axial direction of the outer ring is The radial direction of the outer ring of the shaft is... shaft and axis; Coordinates of any point on the outer raceway The surface equation of the outer raceway satisfies the following equations: ； in, Let be the radius of the highest point of the outer raceway groove; the surface equation of the outer raceway describes the surface of the outer raceway, and its cross-section has a radius of . The arc; Establish a Cartesian coordinate system for the inner ring of a full-load CARB bearing. Let be the coordinate system of the inner circle; the center of the inner circle is the origin. The axial direction of the inner ring is The radial direction of the inner ring of the shaft is... shaft and axis; Coordinates of any point on the inner raceway The surface equation of the inner raceway satisfies the following equations: ； in, Let be the radius of the lowest point of the inner raceway groove; the surface equation of the inner raceway describes the surface of the inner raceway, and its cross-section has a radius of . The arc; Establish a Cartesian coordinate system for the rollers of a full-load CARB bearing Let be the coordinate system of the roller; the center of the roller is the origin. The axial direction of the roller is The radial direction of the shaft and rollers is shaft and axis; coordinates of any point on the roller The surface equation of the roller satisfies the following equations: ； in, Let be the roller radius; the surface equation of the roller describes the roller surface, and its cross-section has a radius of . The arc; (2) Mathematical modeling and analysis of the assembly process; A mathematical model of the assembly process of a fully loaded CARB bearing is established using the inversion method, that is, the bearing assembly process is regarded as the reverse process of disassembling the bearing. In the actual assembly process, the outer ring is in a fixed position, and the rollers and inner ring are installed into the outer ring. The mathematical model of the assembly process of a full complement CARB bearing is as follows: First, the coordinates of the outer ring, inner ring, and rollers are represented in the coordinate systems of the outer ring, inner ring, and rollers, respectively. Then, the coordinates of the inner ring and rollers are transformed to the coordinate system of the outer ring through a pose transformation method. The coordinate system of the outer ring is taken as the generalized Cartesian coordinate system, and the coordinate systems of the inner ring and rollers are taken as local coordinate systems. 1) Initial state and coordinate transformation: In the coordinate system of the outer ring, rollers are sequentially loaded along the circumferential direction of the outer ring raceway. Under the influence of gravity, the loaded rollers gather at the bottom region of the outer ring raceway. The coordinates of the center position of the first loaded roller, i.e., the origin of the roller's coordinate system, are defined as follows at the initial moment: ； 2) Roller offset motion: During assembly, the roller needs to move axially around the tangent of the contact point of the outer raceway while ensuring that the roller surface remains in contact with the raceway surface. The offset angle is... During the offset motion, the constraint roller maintains constant contact with the outer raceway surface; the homogeneous transformation matrix of the roller's coordinate system relative to the outer raceway coordinate system is: [ 1 0 0 0 0 cos θ − sin θ − cos θ ( R outside + r g ) 0 sin θ cos θ − sin θ ( R outside + r g ) 0 0 0 1 ] ； 3) Relative motion of the inner circles: The inner ring moves synchronously relative to the coordinate system of the roller, with an offset angle of . The homogeneous transformation matrix of the inner ring coordinate system relative to the roller coordinate system for this offset motion is: [ 1 0 0 0 0 cos θ − sin θ cos θ ( R Inside + r g ) 0 sin θ cos θ sin θ ( R Inside + r g ) 0 0 0 1 ] ； 4) Position of the center of curvature of the inner raceway after offset: Offset Angle Afterwards, the center of curvature of the inner raceway The coordinates in the outer coordinate system are obtained through cascaded transformations: ( x 3 y 3 z 3 1 ) = [ 1 0 0 0 0 cos θ − sin θ − cos( R outside + r g ) 0 sin θ cos θ − sin( R outside + r g ) 0 0 0 1 ] ； 5) Assembly feasibility criteria: The constraint during assembly is: when the inner ring is offset to an angle... At that time, there must be a radius greater than the roller radius. The space allows the next roller to be inserted radially along the inner raceway surface; a radial clearance greater than the roller diameter is equivalent to calculating the distance from the center of curvature of the inner raceway to a reference point on the roller surface. The reference point is assembly judgment base point P; The position of assembly judgment base point P needs to be determined based on the roller geometry and assembly path, and its coordinates are expressed as follows: ； in, The radius is the point where the outer raceway intersects with both ends of the bearing. distance The calculation formula is: ； Assembly is complete when the geometric relationships satisfy the following formula. 。

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