Manufacturing method of hub sealing element

Abstract

In a method for manufacturing a hub seal according to an embodiment of the present invention, a set rotational speed, which is a rotational speed at which a foreign matter entering an upstream space (S) of a hub seal (1) is positioned at a desired foreign matter surface position in the radial direction by rotation of the hub seal (1) about an axis (x), is set; the shape of the side lip (4) is designed such that the torque of the hub seal (1) at the set rotational speed has a desired value, and the hub seal (1) having the designed shape of the side lip (4) is manufactured.

Description

Technical Field

[0001] The invention relates to a method for manufacturing a wheel hub seal. Background Art

[0002] In vehicles such as automobiles, the wheel hub bearings that rotatably support the wheels are in an environment that is directly exposed to foreign matter such as rain, muddy water, and dust. Therefore, in order to achieve the sealing of the space formed between the outer ring and the wheel hub that can rotate relative to the axis, a hub seal as a sealing device has been installed on the wheel hub bearing. The hub seal seals the lubricant inside the wheel hub bearing and prevents foreign matter from entering the interior. In addition, in such a hub seal, due to the demand for low fuel consumption, etc., in order to reduce the torque required for the rotation of the hub seal, it is required to reduce the sliding resistance (torque resistance) of the sealing lip relative to the rotation of the hub seal. Therefore, in the existing hub seals, there is a structure that seeks to reduce the torque resistance (for example, refer to Patent Document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Registered Utility Model No. 3201207 Summary of the invention

[0006] In order to reduce the torque resistance of the hub seal, a countermeasure of reducing the force of the sealing lip fastening the outer peripheral surface of the hub (the lip reaction force of the sealing lip) can be considered. However, since the reduction of the lip reaction force of the sealing lip will reduce the sealing performance, the reduction of the lip reaction force of the sealing lip is limited to maintaining the required sealing performance. As described above, in the hub seal of the existing hub bearing, in order to maintain the required sealing performance, the reduction of the lip reaction force of the sealing lip is limited, and the reduction of the torque of the hub seal is limited. Therefore, for the hub seal of the existing hub bearing, a structure that can reduce the limit of reducing the torque of the hub seal for maintaining the required sealing performance is required.

[0007] An object of the present invention is to provide a method for manufacturing a hub seal capable of reducing the limit of torque reduction of the hub seal in order to maintain required sealing performance.

[0008] Means for solving problems

[0009] In order to solve the above-mentioned problems, the present invention relates to a method for manufacturing a hub seal, wherein the hub seal has a side lip for sealing the space between the outer ring of the hub bearing and the hub, and a set rotational speed is set, which is a rotational speed at which foreign matter intruding into the interior of the hub seal is located at a desired position in a radial direction orthogonal to the axis by rotation around the axis, and the shape of the side lip is designed so that the torque of the hub seal at the set rotational speed has a desired value, and the hub seal is manufactured to form a hub seal with the designed side lip shape.

[0010] In a manufacturing method of a hub seal involved in one aspect of the present invention, the relationship between the position of a foreign object that has invaded the interior of a basic hub seal through rotation around an axis and the radial direction orthogonal to the axis and the rotation speed is determined, and the basic hub seal is a hub seal having a specified shape. In the determined relationship between the position of the foreign object in the basic hub seal and the rotation speed, it is confirmed whether the position of the foreign object at the set rotation speed is the desired position.

[0011] In a manufacturing method of a hub seal involved in one aspect of the present invention, the relationship between the position of a foreign object that has intruded into the interior of a modified basic hub seal through rotation around an axis and the radial direction orthogonal to the axis and the rotation speed is determined, and the modified basic hub seal has a shape obtained by changing the shape of the basic hub seal. In the determined relationship between the position of the foreign object in the modified basic hub seal and the rotation speed, it is confirmed whether the position of the foreign object at the set rotation speed is the desired position.

[0012] In the method for manufacturing a hub seal according to one aspect of the present invention, the shape of the space of the modified basic hub seal which is farther from the space between the outer ring and the hub than the side lip of the basic hub seal is modified.

[0013] In a manufacturing method of a hub seal involved in one aspect of the present invention, the side lip is designed by adjusting at least any one of the thickness of the front end portion of the side lip, the thickness of the root of the side lip, and the length of the root of the side lip so that the torque of the hub seal at the set speed has the desired value.

[0014] In a manufacturing method of a hub seal involved in one aspect of the present invention, the side lip is designed by adjusting at least any one of the thickness of the front end portion of the side lip of the basic hub seal, the thickness of the root of the basic side lip, and the length of the root of the basic side lip so that the torque of the hub seal at the set speed has the desired value.

[0015] In a manufacturing method of a hub seal involved in one aspect of the present invention, the side lip is designed by adjusting at least any one of the thickness of the front end portion of the side lip of the changed basic hub seal, the thickness of the root portion of the changed basic side lip, and the length of the root portion of the changed basic side lip so that the torque of the hub seal at the set speed has the desired value.

[0016] Effects of the Invention

[0017] According to the method for manufacturing a hub seal according to the present invention, it is possible to reduce the limit of torque reduction of the hub seal in order to maintain required sealing performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a diagram showing an example of a hub seal manufactured by the method for manufacturing a hub seal according to the present invention.

[0019] Figure 2 It is enlarged to show Figure 1 An enlarged cross-sectional view of the side lip of the hub seal is shown.

[0020] Figure 3 It is a partial enlarged cross-sectional view of the side lip.

[0021] Figure 4 It is a cross-sectional view of the hub bearing along the axis line for illustrating a usage state of the hub seal mounted on the hub bearing.

[0022] Figure 5 yes Figure 4 A partial enlarged cross-sectional view of the area near the wheel hub seal.

[0023] Figure 6 It is a schematic diagram used to explain the foreign matter throwing-off effect of the wheel hub seal.

[0024] Figure 7 The graphs are for showing the relationship between the torque of the hub seal and the rotation speed of the hub seal, and the relationship between the foreign matter surface position and the rotation speed of the hub seal.

[0025] Figure 8 The graphs are for showing the relationship between the torque of the hub seal and the rotation speed of the hub seal, and the relationship between the foreign matter surface position and the rotation speed of the hub seal.

[0026] Fig. 9 An example of a basic hub seal is shown, and is a cross-sectional view of a section along the axis of the basic hub seal.

[0027] Fig.10 It is a partial cross-sectional view showing, in an enlarged manner, a basic hub seal or a side lip of a modified basic hub seal.

[0028] Fig.11 This is a diagram showing a graph of the relationship between the foreign matter surface position and the rotation speed, which is an example of poor foreign matter rejection performance confirmed in the foreign matter rejection performance confirmation step of the basic hub seal.

[0029] Fig.12 : is a graph showing a curve for indicating the relationship between the thickness of the front end portion of the side lip and the torque performance.

[0030] Fig.13 2 is a diagram showing a curve indicating the relationship between the thickness of the root of the side lip and the torque performance.

[0031] Fig.14 1 is a diagram showing the flow of a hub seal manufacturing process for manufacturing a hub seal.

[0032] Fig.15 1 is a diagram showing the flow of a hub seal manufacturing process for manufacturing a hub seal.

[0033] Fig.16 1 is a diagram showing the flow of a hub seal manufacturing process for manufacturing a hub seal.

[0034] Fig.17 This is a diagram showing another example of a hub seal manufactured by the method for manufacturing a hub seal according to the present invention.

[0035] Fig.18 This is a cross-sectional view of an example of an in-wheel motor unit using a hub seal manufactured by the method for manufacturing a hub seal according to the present invention. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0037] Figure 1 The figure shows an example of a hub seal manufactured by the manufacturing method of the hub seal according to the present invention, and is a cross-sectional view of a section along the axis x of the hub seal 1 manufactured by the manufacturing method of the hub seal according to the present invention. The hub seal manufactured according to the manufacturing method of the hub seal according to the present invention is a sealing device for sealing the space between an outer peripheral side component and an inner peripheral side component at least partially surrounded by the outer peripheral side component, and the outer peripheral side component has a side lip and can rotate relative to each other. The hub seal 1 manufactured by the manufacturing method of the hub seal according to the present invention is specifically used for a hub bearing 50 of an automobile, as described later, and is used to seal the space between an outer ring 51 as an outer peripheral side component that can rotate relative to the axis and a hub 52 as an inner peripheral side component (refer to Figure 3). In addition, the hub seal manufactured by the manufacturing method of the hub seal according to the present invention is not limited to the hub bearing of a vehicle such as an automobile, and the hub seal manufactured by the manufacturing method of the hub seal according to the present invention can also be applied to other bearings other than the hub bearing of a vehicle, such as bearings used in industrial machinery or general machinery.

[0038] In the following, for the convenience of explanation, the arrow a (refer to Figure 1 ) direction (the side in the axial direction) as the outer side, and the arrow b (refer to Figure 1 ) direction (the other side in the axial direction) is taken as the inner side. More specifically, the outer side refers to the side in the direction of the axis x that is away from the space between the outer ring 51 and the hub 52, which is the sealing object space, and the inner side refers to the side in the direction of the axis x that is close to the sealing object space. In addition, in the direction perpendicular to the axis x (hereinafter also referred to as the "radial direction"), the direction away from the axis x ( Figure 1 The side with the arrow c direction as the outer peripheral side is the side close to the axis x ( Figure 1 The side in the direction of arrow d) is regarded as the inner circumference side.

[0039] like Figure 1 As shown, the hub seal 1 includes: a seal body 2 as a first sealing component, which is mounted on the rotating side of the hub bearing 50, that is, the hub 52; and a sleeve 3 as a second sealing component, which is mounted on the fixed side of the hub bearing 50, that is, the outer ring 51. The seal body 2 and the sleeve 3 are annular components around the axis x. The seal body 2 has an annular side lip 4 around the axis x. In the hub seal 1, foreign matter such as rainwater, muddy water, dust, etc. that enters the inside of the hub seal 1 is located at a desired position in the radial direction by rotating around the axis at a preset speed, that is, a set speed. The set speed is, for example, the practical speed of the hub bearing 50 to which the hub seal 1 is installed, which will be described later. In addition, the side lip 4 is designed to have a shape in which the torque of the hub seal 1 at the set speed has a desired value. The torque of the hub seal 1 is the torque required to rotate the hub seal 1 in order to resist the sliding resistance (torque resistance) of the side lip 4 based on the lip reaction force of the side lip 4, that is, the torque required to relatively rotate the seal body 2 and the sleeve 3. The structure of the hub seal 1 is described in detail below.

[0040] For example, Figure 1As shown, the seal body 2 includes a reinforcement ring 10 which is an annular component around the axis x and an elastic body portion 20 which is mounted on the reinforcement ring 10 and is formed by an annular elastic body around the axis x. The elastic body portion 20 has a side lip 4. The side lip 4 is a sealing lip extending from the outside (the side in the direction of arrow a) to the inside (the side in the direction of arrow b) formed in contact with the sleeve 3 when the hub seal 1 described later is mounted on the hub bearing 50. Figure 1 In the figure, the seal body 2 and the sleeve 3 are shown in relative positions in the use state.

[0041] For example, Figure 1 As shown, the reinforcement ring 10 is a metal member having an annular or substantially annular shape with the axis x as the center or substantially the center, and is formed so that the hub 52 of the hub bearing 50 described later as the installation object is pressed into the reinforcement ring 10 and the reinforcement ring 10 is fitted and installed on the hub 52. The reinforcement ring 10 has, for example, a cylindrical portion located on the inner circumference side, namely a barrel portion 11, and an annular portion extending from the outer end of the barrel portion 11 to the outer circumference side, namely an annular portion 12. As described above, the barrel portion 11 is formed in a shape in which the hub 52 is embedded in an interference fit manner so that the reinforcement ring 10 is embedded in the hub 52. In addition, the annular portion 12 has an annular or substantially annular portion extending parallel to or substantially parallel to the radial direction. The elastic body portion 20 is installed on the reinforcement ring 10 from the substantially outer circumference side and the inner side to reinforce the elastic body portion 20. In addition, the material of the reinforcement ring 10 is not limited to metal.

[0042] For example, Figure 1 As shown, the elastic body portion 20 has: a base portion 21, which is a portion mounted on the outer peripheral side of the annular portion 12 of the reinforcement ring 10; and a cylindrical portion 22, which is a portion mounted on the inner peripheral side of the annular portion 12 of the reinforcement ring 10 and the cylindrical portion 11. In the elastic body portion 20, the side lip 4 extends from the base portion 21. The elastic body portion 20 is a component formed integrally of the same elastic material, and the side lip 4, the base portion 21, and the cylindrical portion 22 are parts of the elastic body portion 20 formed integrally.

[0043] Figure 2 FIG. 4 is an enlarged cross-sectional view showing the side lip 4 in an enlarged manner. Figure 2 In FIG. 4 , the side lip 4 is shown in a natural state, the side lip 4 is not in contact with the sleeve 3, and no external force is applied. Figure 1 , 2 As shown, the side lip 4 extends inwardly in an annular shape from the base portion 21 with the axis x as the central axis or substantially the central axis, and the surface of the side lip 4 facing the inner peripheral side (inner peripheral surface 41c) forms a contact surface 4a for sealing the space between the outer ring 51 and the hub 52. In addition, the side lip 4 is formed so that, in the use state of the hub seal 1 described later, the contact surface 4a of the front end portion 41 contacts the contact surface 33 of the sleeve 3 described later with a predetermined interference.

[0044] like Figure 1 , 2 As shown in FIG. 1 , the side lip 4 has a front end portion 41 and a root portion 42. The root portion 42 is a portion connected to the base portion 21 of the side lip 4, and the front end portion 41 is a portion located further toward the front end side (inside) than the root portion 42 of the side lip 4. The root portion 42 extends parallel to or substantially parallel to the axis x, for example, Figure 2 As shown, the front end portion 41 has a cylindrical or substantially cylindrical shape with the axis x as the central axis or substantially the central axis. The front end portion 41 has a shape with the axis x as the central axis or substantially the central axis and the diameter increases as it goes inward along the axis x.

[0045] like Figure 2 As shown, in the cross section of the front end portion 41, the thickness of the end on the front end side (front end 41a) is thickness T1, and the thickness of the end on the root side (root end 41b) is thickness T2. In addition, the root end 41b is a virtual end of the front end portion 41. Figure 2 As shown, the front end portion 41 extends along the extension direction line c1 as an imaginary line in the cross section, and has a shape that is symmetrical or substantially symmetrical about the extension direction line c1. That is, the inner peripheral surface 41c as the surface facing the inner peripheral side of the front end portion 41 and the outer peripheral surface 41d as the surface facing the outer peripheral side of the front end portion 41 are symmetrical or substantially symmetrical about the extension direction line c1. For example, Figure 2 As shown, the extension direction line c1 is a straight line that is inclined toward the inner side and the outer peripheral side relative to the axis x. In addition, the extension direction line c1 may not be a straight line, but may be a curve, a line combining a straight line and a curve, etc. In addition, the inner peripheral surface 41c and the outer peripheral surface 41d may not be partially symmetrical with respect to the extension direction line c1, and may be asymmetrical with respect to the extension direction line c1.

[0046] The thickness T1 and T2 are the widths between the inner peripheral surface 41c and the outer peripheral surface 41d in the direction perpendicular to the extension direction line c1. Figure 2 As shown, the thickness T1 is the width between the inner peripheral front end 41e as the front end 41a in the inner peripheral surface 41c and the outer peripheral front end 41f as the front end 41a in the outer peripheral surface 41d in the direction perpendicular to the extension direction line c1. In addition, the thickness T2 is the width of the root end 41b in the outer peripheral surface 41d, that is, the outer peripheral root end 41h in the direction perpendicular to the extension direction line c1.

[0047] In addition, the length of the front end portion 41 in the direction of the extension direction line c1 is the length L1. Figure 2As shown, the length L1 of the front end portion 41 is the length between the inner peripheral front end 41e and the inner peripheral root end 41g in the direction of the extension direction line c1. In addition, the inner peripheral root end 41g is the root end 41b in the inner peripheral surface 41c. The length L1 of the front end portion 41 may also be the length between the outer peripheral front end 41f and the outer peripheral root end 41h in the direction of the extension direction line c1.

[0048] like Figure 2 As shown, in the cross section of the root 42, the thickness of the root 42 is the same thickness (thickness T3). The thickness of the root 42 may also be substantially the same as the thickness T3. Figure 2 As shown, the root 42 extends along the extension direction line c2 as an imaginary line in the cross section, and has a shape that is symmetrical or substantially symmetrical about the extension direction line c2. That is, the surface facing the inner circumference side of the root 42, i.e., the inner circumference surface 42c, and the surface facing the outer circumference side of the root 42, i.e., the outer circumference surface 42d, are symmetrical or substantially symmetrical about the extension direction line c2. For example, Figure 2 As shown, the extension direction line c2 is a straight line parallel or substantially parallel to the axis x. In addition, the extension direction line c2 may not be a straight line, but may be a curve, a line combining a straight line and a curve, etc. In addition, the inner circumferential surface 42c and the outer circumferential surface 42d may not be partially symmetrical about the extension direction line c2, and may also be asymmetrical about the extension direction line c2. In addition, the extension direction line c2 may also be inclined relative to the axis x.

[0049] The thickness T3 is the width between the inner peripheral surface 42c and the outer peripheral surface 42d in the direction orthogonal to the extension direction line c2. Figure 2 As shown, the thickness T3 is the width between any point on the inner peripheral surface 42c or the outer peripheral surface 42d and the point on the outer peripheral surface 42d or the inner peripheral surface 42c opposite to the point in the direction orthogonal to the extension direction line c2. The thickness T3 may also be the width in the direction orthogonal to the extension direction line c2 between the end (root end 42b) on the side of the base portion 21 in the inner peripheral surface 42c, i.e., the inner peripheral root end 42g and the root end 42b in the outer peripheral surface 42d, i.e., the outer peripheral root end 42h. The thickness T3 may also be the width in the direction orthogonal to the extension direction line c2 between the end (front end 42a) on the side of the front end portion 41 in the inner peripheral surface 42c, i.e., the inner peripheral front end 42e and the front end 42a in the outer peripheral surface 42d, i.e., the outer peripheral front end 42f. In addition, the front end 42a and the root end 42b are imaginary ends of the root 42.

[0050] In addition, the length of the root 42 in the direction of the extension direction line c2 is the length L2. Figure 2As shown, the length L2 of the root 42 is the length between the inner peripheral front end 42e and the inner peripheral root end 42g in the direction of the extension direction line c2. The length L2 of the root 42 can also be the length between the outer peripheral front end 42f and the outer peripheral root end 42h in the direction of the extension direction line c2.

[0051] like Figure 3 As shown, a transition portion 43 may be formed between the front end portion 41 and the root portion 42 to smoothly connect the front end portion 41 and the root portion 42. Figure 3 As shown, a transition portion 44 may be formed between the root portion 42 and the base portion 21 to smoothly connect the root portion 42 and the base portion 21. Specifically, as Figure 3 As shown, the transition portion 43 is an inner circumferential transition surface 43a which is a surface connecting the inner circumferential surface 41c of the front end portion 41 and the inner circumferential surface 42c of the root portion 42, and an outer circumferential transition surface 43b which is a surface connecting the outer circumferential surface 41d of the front end portion 41 and the outer circumferential surface 42d of the root portion 42. Figure 3 As shown in FIG. 4 , the inner circumferential transition surface 43a is formed in a cross section to depict a curve protruding toward the inner circumference. Figure 3 As shown, the outer peripheral transition surface 43b is formed in a shape that describes a curve that is recessed toward the inner peripheral side in cross section.

[0052] Specifically, Figure 3 As shown, the transition portion 44 is an inner circumferential transition surface 44a which is a surface connecting the inner circumferential surface 42c of the root portion 42 and the inner side surface 21a of the base portion 21, and an outer circumferential transition surface 44b which is a surface connecting the outer circumferential surface 42d of the root portion 42 and the inner side surface 21a of the base portion 21. Figure 3 As shown in FIG. 4 , the inner circumferential transition surface 44a is formed in a cross section to depict a curve that is concave toward the outer circumference. Figure 3 As shown, the outer peripheral transition surface 44b is formed in a shape that describes a curve that is recessed toward the inner peripheral side in cross section.

[0053] In this case, for example, Figure 3 As shown, the root end 41b of the front end portion 41 and the front end 42a of the root 42 pass through the imaginary intersection vp1 of the imaginary extension line of the inner peripheral surface 41c of the front end portion 41 and the imaginary extension line of the inner peripheral surface 42c of the root 42 in the cross section, and the imaginary intersection vp2 of the imaginary extension line of the outer peripheral surface 41d of the front end portion 41 and the imaginary extension line of the outer peripheral surface 42d of the root 42.

[0054] like Figure 2As shown, in the front end portion 41, for example, the thickness T1 is greater than the thickness T2, and the front end portion 41 is formed in a shape where the thickness of the front end portion 41 becomes thicker as it moves from the root end 41b toward the front end 41a along the extension direction line c1. In addition, the thickness of the front end portion 41 is the width between the inner peripheral surface 41c and the outer peripheral surface 41d in the direction orthogonal to the extension direction line c1 in the cross section. Figure 2 As shown, the angle (angle θ) between the extension direction line c1 and the extension direction line c2 is greater than 90° and less than 180° (90°<θ<180°).

[0055] In addition, if Figure 2 As shown, in the root portion 42, for example, the thickness T3 is the same over the length L2. In addition, the thickness T3 of the root portion 42 is, for example, smaller than the thickness T2 of the root end 41b of the front end portion 41. In addition, the thickness T3 of the root portion 42 may be greater than the thickness T2 of the root end 41b of the front end portion 41.

[0056] The side lip 4 has the above-mentioned shape. In the state of use described later, the portion of the front end 41a side of the inner peripheral surface 41c of the front end portion 41 contacts the contact surface 33 of the sleeve 3 with a predetermined interference amount (contact surface 4a) to generate a predetermined reaction force (lip reaction force). The interference amount of the sealing lip is the length of the sealing lip in a free state that is not deformed by external force and protrudes from the contact surface that the sealing lip contacts in the state of use. Specifically, the interference amount of the side lip 4 is greater than Figure 2 The contact surface indicated by the imaginary line V, that is, the length of the portion of the inner peripheral surface 41 c of the front end portion 41 of the side lip 4 where the contact surface 33 of the sleeve 3 protrudes in the direction of the axis line x.

[0057] In addition, the side lip 4 has the above-mentioned shape, and as described later, it plays a desired throwing-off effect in the use state. The throwing-off effect refers to the effect of moving foreign matter, especially liquid foreign matter, that has entered the hub seal 1 from the side lip 4 to the outer peripheral side through the centrifugal force generated by the rotation around the axis x.

[0058] The elastic body portion 20 is integrally mounted on the reinforcement ring 10 , and the side lip 4 and the base portion 21 are parts of the elastic body portion 20 integrally formed of the same material and are integrally continuous.

[0059] For example, Figure 1As shown, the sleeve 3 is a metal member in an annular or substantially annular shape with the axis x as the center or substantially the center, and is formed to be pressed into the outer ring 51 of the hub bearing 50 to be installed, which will be described later, and is fitted on the outer ring 51. The sleeve 3 has, for example, a cylindrical portion located on the outer peripheral side, namely a barrel portion 31, and an annular or substantially annular portion extending from the inner end of the barrel portion 31 to the inner peripheral side, namely an annular portion 32. As described above, the barrel portion 31 is formed in a shape that is embedded in the outer ring 51 in an interference fit manner so that the sleeve 3 is fitted in the outer ring 51. In addition, the annular portion 32 has an annular or substantially annular portion extending parallel to or substantially parallel to the radial direction. A contact surface 33 is formed on the annular portion 32, and the contact surface 33 is a surface that contacts the side lip 4 in the use state described later. The contact surface 33 is a surface of the annular portion 32 facing outward, and is an annular plane or substantially plane extending around the axis x in parallel or substantially parallel to a plane perpendicular or substantially perpendicular to the axis x. The material of the sleeve 3 is not limited to metal.

[0060] Next, the use state of the above-mentioned hub seal 1 will be described. Figure 4 is a cross-sectional view of the hub bearing 50 along the axis x for illustrating the use state of the hub seal 1 mounted on the hub bearing 50, Figure 5 yes Figure 4 1 is a partial enlarged cross-sectional view of the hub seal 1 and its vicinity. In the example shown in the figure, the axis of the hub bearing 50 coincides with the axis x of the hub seal 1 , and the hub bearing 50 has a common axis x with the hub seal 1 .

[0061] like Figure 4 As shown, the hub bearing 50 is a conventionally known hub bearing, which is an inner ring rotating hub bearing, and is provided on a vehicle such as an automobile, etc., and rotatably supports the wheel in the axle or suspension device. Specifically, as shown in FIG. Figure 4As shown, the hub bearing 50 includes: an annular outer ring 51 as an outer peripheral member with the axis x as the central axis or substantially the central axis; a hub 52 as an inner peripheral member which is relatively rotatable relative to the outer ring 51 and partially surrounded by the outer ring 51 and with the axis x as the central axis or substantially the central axis; and a plurality of bearing balls 53 arranged in two rows between the outer ring 51 and the hub 52. When the hub bearing 50 is mounted on a vehicle or the like, the outer ring 51 is fixed to, for example, a suspension device of the vehicle, and the hub 52 is relatively rotatable relative to the outer ring 51. Specifically, the hub 52 includes an inner ring 54 and a hub wheel 55, and the hub wheel 55 includes a substantially cylindrical shaft portion 55a extending along the axis x and a wheel mounting flange 55b. The wheel mounting flange 55b is a portion extending in an annular shape from one end of the outer side of the shaft portion 55a toward the outer peripheral side, and is a portion to which a wheel (not shown) is mounted through a plurality of hub bolts 59. The inner ring 54 is fitted to the inner end of the shaft portion 55a of the hub wheel 55 in order to hold the bearing balls 53 in the space between the outer ring 51 and the hub 52. The bearing balls 53 are held by a retainer 56 in the space between the outer ring 51 and the hub 52, that is, in the sealed space S1.

[0062] The outer ring 51 has a through hole 57 extending in the direction of the axis x, and the shaft 55a of the hub wheel 55 of the hub 52 is inserted into the through hole 57, and an annular sealed space S1 extending along the axis x is formed between the shaft 55a and the through hole 57. In addition, a lubricant is applied or injected into the sealed space S1. The inner opening 50a of the hub bearing 50, which is opened inwardly, is formed in the space between the shaft 55a and the through hole 57. The hub seal 1 is installed in the outer opening 50b of the hub bearing 50, which is opened inwardly, is formed in the space between the shaft 55a and the through hole 57. Another sealing device 58 is installed in the outer opening 50b of the hub bearing 50, which is opened inwardly. The hub seal 1 and the sealing device 58 are used to seal the space between the shaft 55a and the inner ring 54 and the through hole 57, thereby preventing the lubricant in the sealed space S1 from leaking to the outside and preventing foreign matter such as rainwater, muddy water, and dust from entering the inside from the outside. The sealing device 58 is a conventionally known sealing device, and a detailed description thereof is omitted. In addition, the hub seal 1 may also be applied as the sealing device 58. The structure of the hub bearing to which the hub seal 1 is applied is not limited to the structure of the hub bearing 50 described above.

[0063] like Figure 4 , Figure 5As shown, specifically, the sleeve 3 of the hub seal 1 is mounted on the cylindrical end 51a on the inner side of the outer ring 51, and further, the reinforcing ring 10 of the seal body 2 of the hub seal 1 is mounted on the cylindrical end 54a on the inner side of the inner ring 54 of the hub 52, and the hub seal 1 is mounted on the hub bearing 50. Specifically, the sleeve 3 is fixed to the outer ring 51 by press-fitting the cylindrical portion 31 into the inner opening portion 50a of the outer ring 51. In addition, the end 54a of the inner ring 54 is pressed into the cylindrical portion 11 of the reinforcing ring 10, and the reinforcing ring 10 is fitted on the inner ring 54, thereby fixing the seal body 2 to the inner ring 54.

[0064] In the use state, the seal body 2 and the sleeve 3 are positioned at a specified interval in the direction of the axis x, and the front end side portion of the inner circumferential surface 41c of the front end portion 41 of the side lip 4 is in slidable contact with the contact surface 33 of the sleeve 3 at the portion (contact surface 4a) corresponding to the above-mentioned specified interference amount. The side lip 4 can prevent foreign matter from entering the sealing space S1, and can prevent the lubricant from flowing out of the sealing space S1. In addition, in the hub seal 1, grease can also be applied to the inner circumferential surface 41c of the side lip 4, thereby, in the use state, grease (not shown) can also be interposed between the contact surface 4a of the side lip 4 and the contact surface 33 of the annular portion 32 of the sleeve 3.

[0065] As described above, in the use state, the contact surface 4a of the side lip 4 contacts the contact surface 33 of the sleeve 3 with a predetermined interference, and a reaction force (lip reaction force F) is generated on the side lip 4 based on the contact. Figure 5 As shown in FIG. 1 , the lip reaction force F of the side lip 4 is the force in the axis x direction applied by the side lip 4 to the contact surface 33 of the annular portion 32 of the sleeve 3 when the hub seal 1 is in use. The lip reaction force F of the side lip 4 becomes the torque resistance of the hub seal 1 rotation. That is, the torque of the hub seal 1 is a value corresponding to the lip reaction force F of the side lip 4. As an example, Figure 2 As shown, the factors of the side lip 4 that determine the lip reaction force F of the side lip 4 include: the length L1 of the front end portion 41 of the side lip 4, the thickness T1, T2 of the front end portion 41 of the side lip 4, the thickness T3 of the root 42 of the side lip 4, the bending angle θ of the side lip 4, and the surface roughness of the inner peripheral surface 41c of the front end portion 41 of the side lip 4.

[0066] The lip reaction force F of the side lip 4 changes according to the rotation speed of the hub 52. This is because, when the hub 52 rotates, the centrifugal force applied to the side lip 4 of the seal body 2 that rotates around the axis x together with the hub 52 generates a force in the direction of causing the side lip 4 to leave the contact surface 33 of the sleeve 3. The centrifugal force applied to the side lip 4 increases as the rotation speed of the hub 52 (seal body 2) increases, and accordingly, the force in the direction of causing the side lip 4 to leave the contact surface 33 of the sleeve 3 also increases, and thus, the lip reaction force F of the side lip 4 decreases as the rotation speed of the hub 52 increases. When the rotation speed of the hub 52 is higher than a predetermined rotation speed, the force in the direction of causing the side lip 4 to leave the contact surface 33 of the sleeve 3 becomes large enough to completely leave the side lip 4 from the contact surface 33 of the sleeve 3, and the side lip 4 leaves the contact surface 33 of the sleeve 3.

[0067] On the other hand, due to the centrifugal force generated by the rotation of the hub 52, a throwing-off effect is generated in the hub seal 1. The so-called throwing-off effect is as follows: Figure 6 As shown, it is the effect of moving foreign matter, especially liquid foreign matter, that enters the hub seal 1 from the side lip 4 side to the outer peripheral side. Through the flinging effect, the position of the foreign matter pressed toward the outer peripheral side, that is, the position of the foreign matter surface, changes according to the rotation speed of the hub 52 (seal body 2). The flinging effect on the foreign matter occurs when the hub 52 rotates at a speed higher than a specified speed. Furthermore, in a region of rotation speed higher than the specified speed, as the rotation speed of the hub 52 increases, the degree of the flinging effect becomes stronger, and the foreign matter surface position is closer to the outer peripheral side, that is, located at a position radially away from the side lip 4 from the axis x. As shown Figure 6 As shown in FIG. 1 , before the rotation speed of the hub 52 reaches the specified rotation speed, the foreign body surface position is located at the position of the sealing surface A in the radial direction. When the hub 52 (seal body 2) rotates at a rotation speed higher than the specified rotation speed, the foreign body surface position moves radially toward the outer peripheral side. In addition, the sealing surface A is the contact surface 4a of the side lip 4 and the contact surface 33 of the sleeve 3 (see FIG. Figure 5 ).

[0068] The degree of the swinging action varies depending on the shape of the space (upstream space S) on the side of the hub seal 1 that is farther from the sealing space S1 than the side lip 4. The upstream space S is Figure 5 The portion indicated by grids in FIG. 1 is a space formed between the seal body 2 and the sleeve 3 on the upstream side of the side lip 4 .

[0069] In the hub seal 1, in the practical rotation speed of the hub bearing 50, the lip reaction force F of the side lip 4 that changes according to the rotation speed of the hub 52 due to the action of the centrifugal force and the position of the foreign body surface that changes according to the rotation speed of the hub 52 due to the action of the centrifugal force are set when the hub bearing 50 is stationary, and the torque resistance of the hub seal 1 rotation in the practical rotation speed range is reduced. In addition, even if the lip reaction force F becomes low and the sealing performance of the side lip 4 is reduced in the practical rotation speed range, in order to produce a foreign body throwing-off effect to prevent foreign bodies from exceeding the side lip 4 and entering the sealing space S1 side, the shape of the upstream space S of the hub seal 1 is determined according to the relationship between the lip reaction force F of the side lip 4 that changes according to the rotation speed of the hub seal 1 due to the action of the centrifugal force and the position of the foreign body surface that changes according to the rotation speed of the hub seal 1 due to the action of the centrifugal force.

[0070] In the hub seal 1, the side lip 4 is shaped so that the relationship between the torque of the hub seal 1 and the rotation speed of the hub seal 1 (seal body 2) becomes, for example Figure 7 In addition, in the hub seal 1, the shape of the upstream space S is such that the relationship between the position of the foreign body surface and the rotation speed of the hub seal 1 becomes, for example, Figure 7 The shape of the relationship is shown by the curve. Figure 7 The foreign body surface position is the distance from the sealing surface A in the radial direction (refer to Figure 5 ) is represented by a distance. In addition, the practical rotation speed of the hub bearing 50 is, for example, above 1000 rpm.

[0071] like Figure 7 As shown, the hub seal 1 can fully press the foreign body surface position toward the outer peripheral side by the swinging action at the practical rotation speed of the hub bearing 50. Therefore, at the practical rotation speed of the hub bearing 50, the foreign body surface position is high, and there is no foreign body near the sealing surface A, or there is very little foreign body near the sealing surface A. Therefore, Figure 7 As shown, at the practical rotation speed of the hub bearing 50, the side lip 4 can be formed in which the lip reaction force F becomes low due to the action of the centrifugal force, and the torque of the hub seal 1 can be reduced. Since there is no foreign matter near the sealing surface A, or there is little foreign matter near the sealing surface A, even if the lip reaction force F of the side lip 4 is reduced to a level that allows foreign matter to enter when the foreign matter surface position exists near the sealing surface A, the foreign matter will not exceed the side lip 4 and enter the sealing space S1 side, and the sealing performance of the hub seal 1 will not be lower than the desired sealing performance.

[0072] On the other hand, when the hub bearing 50 rotates at a speed lower than the practical speed, the degree of the throw-off effect is reduced, and the foreign body surface is located close to the sealing surface A or located on the sealing surface A, resulting in a situation where the foreign body surface is low and foreign matter exists near the sealing surface A. On the other hand, if Figure 7As shown, when the hub bearing 50 rotates at a speed lower than the practical speed, in order to maintain sufficient sealing performance, the lip reaction force F is higher than the lip reaction force F at the practical speed. Therefore, even in the rotation area of ​​the hub bearing 50 where the degree of the throw-off effect is low and the foreign matter surface position is low, the foreign matter will not exceed the side lip 4 and enter the sealing space S1 side, and the sealing performance of the hub seal 1 will not be lower than the desired sealing performance.

[0073] As described above, the hub seal 1, at the practical rotation speed of the hub bearing 50, causes the foreign body surface to be located at a position sufficiently closer to the outer circumference than the sealing surface A by the swinging action, and the foreign body surface is located at a high position. However, according to the form of the hub seal 1, such as Figure 8 As shown, at the practical speed of the hub bearing 50, sometimes only the position of the foreign body surface can be pushed to a certain value. Figure 7 In this case, if Figure 8 As shown, in order to make the lip reaction force F a value sufficient to obtain the desired sealing performance, the lip reaction force F is greater than Figure 7 The shape of the side lip 4 may be determined in a manner that is higher in the case of a problem.

[0074] As described above, the hub seal 1 can reduce the limit of reducing the lip reaction force F of the side lip 4 for maintaining the required sealing performance. Therefore, the hub seal 1 can reduce the limit of reducing the torque of the hub seal 1 for maintaining the required sealing performance. As a result, the hub seal 1 can reduce the torque resistance applied by the side lip 4, thereby reducing the torque of the hub seal 1.

[0075] Next, the manufacturing method of the hub seal according to the present invention is described. The manufacturing method of the hub seal according to the present invention is a manufacturing method of the hub seal that can reduce the limit of the lip reaction force of the side lip for maintaining the required sealing performance, as in the above-mentioned hub seal 1. In the manufacturing method of the hub seal according to the embodiment of the present invention for manufacturing the above-mentioned hub seal 1, the rotation speed, i.e., the set rotation speed, is set so that the foreign matter intruding into the upstream space S of the hub seal 1 is located at the desired foreign matter surface position in the radial direction by the rotation of the hub seal 1 around the axis x, and the shape of the side lip 4 is designed in such a way that the torque of the hub seal 1 at the set rotation speed has a desired value, and the hub seal 1 having the designed side lip 4 shape is manufactured. In addition, as described above, the set rotation speed is, for example, the practical rotation speed of the hub bearing 50 as the installation object of the hub seal 1. The manufacturing method of the hub seal according to the embodiment of the present invention is described in detail below.

[0076] In the manufacturing method of the hub seal involved in the embodiment of the present invention, first, a basic hub seal 5 having a basic form is designed. The basic form is determined according to the shape, size, required performance value, etc. required for the manufactured hub seal. The required shape and size are, for example, the shape and size required by the space of the installation object such as the hub bearing on which the manufactured hub seal is installed. In addition, one of the required performance values ​​is the required torque value of the manufactured hub seal. The required torque value of the hub seal is the required value of the torque required to rotate the hub seal, which is the required value of the torque required to rotate the seal body 2 and the sleeve 3 relative to each other against the torque resistance based on the lip reaction force F of the side lip. Specifically, the required torque value of the hub seal is the maximum value (maximum torque) of the torque required to rotate the hub seal within the practical rotation speed range of the installation object. The maximum torque is, for example, 10N·cm at a practical rotation speed of more than 1000rpm.

[0077] Fig. 9 FIG. 1 shows an example of a basic hub seal 5 , which is a cross-sectional view of a cross section of the basic hub seal 5 along the axis x. Fig.10 FIG. 2 is a partial cross-sectional view showing an enlarged side lip 6 of the basic hub seal 5. Fig. 9 In FIG. 1 , only one side section relative to the axis x is shown. In addition, Fig. 9 The relative positions of the seal body 2 and the sleeve 3 in the use state are shown in FIG. The basic hub seal 5 is different from the hub seal 1 in that only the shape of the side lip is different, such as Fig. 9 , 10 As shown, the side lip 6 has a front end portion 41 with a uniform thickness over a length L1. The size and shape of the reinforcement ring 10 and sleeve 3 of the basic hub seal 5 correspond to the size and shape of the space where the hub seal of the hub bearing 50 to be installed is installed.

[0078] When designing the basic hub seal 5, the degree of foreign matter rejection effect (foreign matter rejection performance) of the designed basic hub seal 5 is confirmed. In confirming the foreign matter rejection performance, as shown in FIG. Figure 7As shown, the relationship between the position of the foreign body surface in the basic hub seal 5 and the rotation speed of the hub seal 1 (the rotation speed of the relative rotation between the seal body 2 and the sleeve 3) is confirmed. The foreign body ejection performance is confirmed by installing the basic hub seal 5 on the hub bearing 50, rotating the hub bearing 50 (the relative rotation between the outer ring 51 and the hub 52), and confirming the foreign body surface position at each rotation speed. The foreign body ejection performance can also be confirmed by installing the basic hub seal 5 on a fixture that simulates the hub bearing 50. In addition, the relationship between the foreign body surface position and the rotation speed of the hub seal or the rotation speed of the hub can be mathematically formulated, and the foreign body ejection performance of the basic hub seal 5 can be calculated based on the mathematical formula, thereby confirming the foreign body ejection performance. In addition, the confirmation of the foreign body ejection performance can be carried out by computer analysis, or by a method different from the above method.

[0079] If the confirmed foreign matter rejection performance of the basic hub seal 5 is a predetermined good performance, the process moves to adjustment and confirmation of the torque performance of the basic hub seal 5. Within the practical rotation speed range of 1000 rpm or more, for example, when the foreign matter surface position is sufficiently high, it is determined to be a good foreign matter rejection performance. For example, if Figure 7 As shown in the curve, within the practical speed range above 1000 rpm, if the foreign body surface position is at a height above the specified radial position, i.e., the reference position Z (Z is, for example, 12 cm), it is judged that the foreign body rejection performance of the basic hub seal 5 is good.

[0080] On the other hand, when the confirmed foreign matter rejection performance of the basic hub seal 5 is not the prescribed good performance, the basic hub seal 5 is redesigned to improve the foreign matter rejection performance of the basic hub seal 5 without adjusting and confirming the torque performance of the basic hub seal 5. In the practical rotation speed range of 1000 rpm or more, for example, when the position of the foreign matter surface does not reach a sufficient height, it cannot be said that the foreign matter rejection performance is good. For example, if Fig.11 As shown in the curve, within the practical speed range above 1000 rpm, if the foreign body surface position is lower than the specified radial position, i.e., the reference position Z (Z is, for example, 12 cm), it is judged that the foreign body rejection performance of the basic hub seal 5 is not good.

[0081] The redesign of the basic hub seal 5 for improving the foreign matter throwing-off performance of the basic hub seal 5 is carried out by changing the structure that affects the foreign matter throwing-off performance of the basic hub seal 5, and designing a modified basic hub seal with a changed structure that affects the foreign matter throwing-off performance of the basic hub seal 5. The structure that affects the foreign matter throwing-off performance of the basic hub seal 5 is, for example, the shape of the upstream space S of the basic hub seal 5. Then, for the modified basic hub seal, the foreign matter throwing-off performance is confirmed in the same way as the confirmation of the foreign matter throwing-off performance of the basic hub seal 5 mentioned above. In the case where the confirmed foreign matter throwing-off performance of the modified basic hub seal is a prescribed good performance, the adjustment and confirmation of the torque performance of the modified basic hub seal is transferred. On the other hand, in the case where the confirmed foreign matter throwing-off performance of the modified basic hub seal is not a prescribed good performance, the modified basic hub seal is redesigned in order to improve the foreign matter throwing-off performance of the modified basic hub seal, and a new modified basic hub seal is designed, similar to the redesign of the basic hub seal 5. In this way, the redesign of the modified basic hub seal is repeatedly performed until the foreign matter discharge performance of the redesigned new modified basic hub seal reaches the prescribed good performance.

[0082] For the basic hub seal 5 or the modified basic hub seal that is judged to have a good foreign matter rejection performance as specified, the torque performance is adjusted and confirmed. The torque performance adjustment and confirmation process is a process of adjusting the morphological elements of the side lip 6 that affect the torque performance of the basic hub seal 5 or the modified basic hub seal, and confirming whether the torque performance of the basic hub seal 5 or the modified basic hub seal having the adjusted side lip 6 meets the above-mentioned required torque value. In addition, the torque performance of the hub seal is the relationship between the rotational speed of the hub seal and the torque required for the rotation of the hub seal at each rotational speed. The lip reaction force F of the side lip becomes the torque resistance to the rotation of the hub seal, affecting the torque performance of the hub seal. Therefore, the morphological element of the side lip that affects the lip reaction force F of the side lip becomes the morphological element of the side lip 6 that affects the torque performance of the hub seal. As mentioned above, the factors of the side lip 6 that determine the lip reaction force F of the side lip 6 include, as an example, the length L1 of the front end portion 41 of the side lip 6, the thicknesses T1 and T2 of the front end portion 41 of the side lip 6, the thickness T3 of the root portion 42 of the side lip 6, the bending angle θ of the side lip 6, and the surface roughness of the inner peripheral surface 41c of the front end portion 41 of the side lip 4 (see Fig.10 ), which are examples of the morphological elements of the side lip that affect the torque performance of the hub seal.

[0083] In the step of adjusting and confirming the torque performance, the morphological elements that determine the lip reaction force F of the side lip 6 are adjusted, the shape of the side lip 6 is adjusted from the basic shape, and the torque performance of the basic hub seal 5 or the modified basic hub seal having the adjusted side lip 6 satisfies the required torque value. The lip reaction force F of the side lip 6 of the basic hub seal 5 or the modified basic hub seal at each rotation speed can be calculated by computer analysis, and the torque of the basic hub seal 5 or the modified basic hub seal is calculated or estimated based on the lip reaction force F of the side lip 6 at each rotation speed calculated by the computer analysis. The lip reaction force F of the side lip 6 at each rotation speed can also be obtained by mounting the basic hub seal 5 or the modified basic hub seal on the hub bearing 50, rotating the hub bearing 50, and measuring the lip reaction force F at each rotation speed. In addition, the basic hub seal 5 or the modified basic hub seal can be mounted on a jig that simulates the hub bearing 50, and the lip reaction force F of the side lip 6 at each rotation speed can be measured. Furthermore, instead of calculating or measuring the lip reaction force F of the side lip 6 , the torque of the basic hub seal 5 may be measured or changed.

[0084] An example of adjusting the torque performance of the hub seal by adjusting the shape elements of the side lip in the step of adjusting and confirming the torque performance will be described. Fig.12 4 is a graph showing a curve for indicating the relationship between the thickness T1 of the front end portion 41 of the side lip 6 and the torque performance. Fig.12 As shown, the larger the thickness T1 of the front end portion 41 of the side lip 6, the lower the torque of the basic hub seal 5 or the basic hub seal change in the high speed region. That is, the larger the value of the thickness T1 of the front end portion 41 of the side lip 6, the greater the centrifugal force acting on the front end portion 41 of the side lip 6, causing the front end 41a of the front end portion 41 of the side lip 6 to leave the contact surface 33 of the sleeve 3.

[0085] Fig.13 4 is a graph showing a curve for indicating the relationship between the thickness T3 of the root portion 42 of the side lip 6 and the torque performance. Fig.13 As shown, the greater the thickness T3 of the root 42 of the side lip 6, the higher the torque in the high speed region. That is, the greater the value of the thickness T3 of the root 42 of the side lip 6, the more difficult it is for the side lip 6 to bend, and even if the centrifugal force acts on the front end 41 of the side lip 6, the front end 41a of the front end 41 of the side lip 6 is difficult to separate from the contact surface 33 of the sleeve 3.

[0086] In addition, the greater the length L2 of the root 42 of the side lip 6, the lower the torque in the high speed region. However, this is the case when the thickness T1 of the front end portion 41 is sufficiently greater than the thickness T3 of the root 42. That is, the greater the value of the length L2 of the root 42 of the side lip 6 with a small thickness, the easier it is for the side lip 6 to bend when the centrifugal force acts on the front end 41 of the side lip 6, and the easier it is for the front end 41a of the front end 41 of the side lip 6 to leave the contact surface 33 of the sleeve 3.

[0087] Based on the relationship between the morphological elements of the side lip 6 and the torque performance, the morphological elements of the side lip 6 are adjusted to estimate the shape of the side lip 6 at which the torque performance of the hub seal meets the required torque value. Then, the lip reaction force F of the side lip 6 having the estimated shape at each rotation speed is calculated or measured, and the torque of the hub seal is calculated or estimated based on the lip reaction force. Then, it is confirmed whether the calculated or measured torque of the hub seal meets the required torque value. The required torque value is, for example, a maximum torque of 10N·cm or less within a practical rotation speed range of more than 1000rpm. In the case where the calculated or measured torque of the basic hub seal 5 or the changed basic hub seal meets the required torque value, the process moves to the confirmation of the sealing performance. On the other hand, in the case where the calculated or measured torque of the basic hub seal 5 or the changed basic hub seal does not meet the required torque value, the morphological elements of the side lip 6 are adjusted again to estimate the shape of the side lip 6 at which the torque performance meets the required torque value. Then, the lip reaction force F of the side lip 6 having the re-estimated shape at each rotation speed is calculated or measured, and the torque of the hub seal is calculated or estimated based on the lip reaction force F, and it is confirmed whether the calculated or measured torque satisfies the required torque value. When the calculated or measured torque of the hub seal satisfies the required torque value, the process moves to confirmation of the sealing performance. On the other hand, when the calculated or measured torque of the hub seal does not satisfy the required torque value, the morphological elements of the side lip 6 are adjusted again, and the lip reaction force F of the side lip 6 having the re-adjusted shape at each rotation speed is calculated or measured, and the torque of the hub seal is calculated or estimated based on the calculated or measured lip reaction force F, and it is confirmed whether the calculated or measured torque satisfies the required torque value. Thereafter, the morphological elements of the side lip 6 are adjusted in the same manner until the torque performance of the basic hub seal 5 or the basic hub seal is changed to a shape that satisfies the required torque value.

[0088] In the process of confirming the sealing performance, the relationship between the foreign matter ejection performance of the basic hub seal 5 or the modified basic hub seal and the torque performance of the basic hub seal 5 or the modified basic hub seal is confirmed to confirm whether the relationship between the foreign matter ejection performance and the torque performance is good. The confirmation of the relationship between the foreign matter ejection performance and the torque performance is, for example, referring to Figure 7 The relationship between the position of the foreign body surface and the rotation speed of the hub seal and the relationship between the torque and the rotation speed of the hub seal are used. Figure 7 As shown, the relationship between the foreign body surface position and the rotational speed is overlapped with the curve representing the relationship between the torque and the rotational speed to confirm the relationship between the foreign body ejection performance and the torque performance. At each practical rotational speed, when the torque relative to the hub seal reaches a foreign body surface position that is considered sufficient, it is determined that the relationship between the foreign body ejection performance and the torque performance is good, and the hub seal 1 is designed as a hub seal for manufacturing a hub seal of this shape. Then, the hub seal 1 is manufactured.

[0089] On the other hand, at each speed of the practical speed, when the foreign body surface position is not considered sufficient relative to the torque, it is judged that the relationship between the foreign body ejection performance and the torque performance is not good. When it is judged that the relationship between the foreign body ejection performance and the torque performance is not good, in order to make the relationship between the foreign body ejection performance and the torque performance good, in order to adjust the foreign body ejection performance (foreign body surface position at each speed), the basic hub seal 5 or the basic hub seal is redesigned and the foreign body ejection performance is confirmed. Alternatively, when it is judged that the relationship between the foreign body ejection performance and the torque performance is not good, in order to make the relationship between the foreign body ejection performance and the torque performance good, the basic hub seal 5 or the basic hub seal is adjusted and confirmed. Alternatively, when it is judged that the relationship between the foreign body ejection performance and the torque performance is not good, in order to make the relationship between the foreign body ejection performance and the torque performance good, in addition to redesigning the basic hub seal 5 or the basic hub seal, and confirming the foreign body ejection performance, the torque performance of the basic hub seal 5 or the basic hub seal is also adjusted and confirmed. In this way, at least one of the redesign of the basic hub seal 5 or the modified basic hub seal, the confirmation of the foreign matter ejection performance, and the adjustment and confirmation of the torque performance of the basic hub seal 5 or the modified basic hub seal is repeatedly performed until it is determined that the relationship between the foreign matter ejection performance and the torque performance is good. At each practical rotation speed, when the foreign matter surface position is considered sufficient relative to the torque, it is determined that the relationship between the foreign matter ejection performance and the torque performance is good, and the hub seal 1 is designed as a hub seal for manufacturing the hub seal of this shape. Then, the hub seal 1 is manufactured.

[0090] Hereinafter, a method for manufacturing the hub seal 1 will be described in detail. Figures 14 to 16 1 is a diagram showing the flow of a hub seal manufacturing process for manufacturing the hub seal 1 .

[0091] like Figures 14 to 16As shown, in the hub seal manufacturing process, the required values ​​for the hub seal 1 are first set (step S1). As described above, the required values ​​for the hub seal 1 are the shape, size, required performance values, etc. required for the hub seal. In the present embodiment, the required shape and size of the hub seal 1 are set based on the form of the hub bearing 50. In addition, the required torque value is set by setting the maximum torque at a practical rotation speed of more than 1000 rpm to 10 N·cm. Next, in step S2, a basic hub seal 5 suitable for the shape and size set in step S1 is designed. As described above, the basic hub seal 5 is different from the hub seal 1 only in the shape of the side lip, and the thickness of the front end portion 41 has the same side lip 6 over the length L1 (refer to Fig. 9 , Fig.10 ).

[0092] Next, the foreign matter rejection performance of the basic hub seal 5 designed in step S2 is confirmed (step S3). In the confirmation of the foreign matter rejection performance in step S3, as described above, the relationship between the rotation speed of the basic hub seal 5 and the foreign matter surface position of the basic hub seal 5 is confirmed (refer to Figure 7 ), determine whether the foreign body ejection performance of the basic hub seal 5 is good. Specifically, within the practical rotation speed range of more than 1000rpm, confirm whether the foreign body surface position is a height above the specified radial position, that is, the reference position Z (Z is, for example, 12cm). Within this practical rotation speed range, if the foreign body surface position is a height above the reference position Z, it is determined that the foreign body ejection performance of the basic hub seal 5 is good ("Yes" in step S3). If it is determined that the foreign body ejection performance of the basic hub seal 5 is good, transfer to the adjustment and confirmation process of the torque performance of the basic hub seal 5 (step S6). On the other hand, within the practical rotation speed range, if the foreign body surface position is lower than the reference position Z, it is determined that the foreign body ejection performance of the basic hub seal 5 is not good ("No" in step S3).

[0093] In step S3, when it is determined that the foreign matter ejection performance of the basic hub seal 5 is not good ("No" in step S3), the basic hub seal 5 is redesigned to improve the foreign matter ejection performance of the basic hub seal 5 (step S4). In step S4, the structure that affects the foreign matter ejection performance of the basic hub seal 5 is changed to design a changed basic hub seal. The structure that affects the foreign matter ejection performance of the basic hub seal 5 is, for example, the shape of the upstream space S of the basic hub seal 5. Then, the foreign matter ejection performance of the changed basic hub seal is confirmed in the same way as step S3 (step S5). In step S5, when it is determined that the foreign matter ejection performance of the changed basic hub seal is not good ("No" in step S5), the process returns to step S4 and the basic hub seal 5 is redesigned again to improve the foreign matter ejection performance of the basic hub seal 5. At this time, in step S5, in order to improve the foreign matter ejection performance of the modified basic hub seal that is judged to have poor foreign matter ejection performance, the modified basic hub seal may be redesigned to design a new modified basic hub seal. In step S5, the design of the modified basic hub seal (step S4) and the confirmation of the foreign matter ejection performance of the modified basic hub seal (step S5) are repeated until it is judged that the foreign matter ejection performance of the modified basic hub seal is good. Then, in step S5, if it is judged that the foreign matter ejection performance of the modified basic hub seal is good ("yes" in step S5), the process is transferred to the adjustment and confirmation process of the torque performance of the modified basic hub seal (step S6).

[0094] In the adjustment and confirmation process of the torque performance of the basic hub seal 5 or the modified basic hub seal, first, the shape of the side lip of the lip reaction force F that satisfies the required torque value set in step S1 is estimated, and based on the estimation, the morphological elements that determine the lip reaction force F are adjusted to adjust the shape of the side lip 6 from the basic shape (step S6). Next, it is confirmed whether the torque performance of the basic hub seal 5 or the modified basic hub seal having the adjusted side lip 6 satisfies the required torque value set in step S1 (step S7). In the case that the torque performance of the basic hub seal 5 or the modified basic hub seal having the adjusted side lip 6 satisfies the required torque value set in step S1 ("yes" in step S7), transfer to the sealing performance confirmation process (step S10).

[0095] On the other hand, when the torque performance of the basic hub seal 5 or the modified basic hub seal having the adjusted side lip 6 does not satisfy the required torque value set in step S1 ("No" in step S7), the shape of the side lip of the lip reaction force F of the basic hub seal 5 or the modified basic hub seal that satisfies the required torque value set in step S1 is estimated again, and based on the re-estimation, the morphological elements that determine the lip reaction force F are adjusted again to adjust the shape of the side lip 6 (step S8). Then, similarly to step S7, it is confirmed whether the torque performance of the basic hub seal 5 or the modified basic hub seal having the side lip 6 re-adjusted in step S8 satisfies the required torque value set in step S1 (step S9). When the torque performance of the basic hub seal 5 or the modified basic hub seal having the re-adjusted side lip 6 satisfies the required torque value set in step S1 ("Yes" in step S9), the process is transferred to the sealing performance confirmation step (step S10).

[0096] On the other hand, in step S9, when the torque performance of the basic hub seal 5 or the modified basic hub seal having the re-adjusted side lip 6 does not satisfy the required torque value set in step S1 ("No" in step S9), the process returns to step S8, the shape of the side lip of the lip reaction force F of the basic hub seal 5 or the modified basic hub seal is estimated again to satisfy the required torque value set in step S1, and based on the re-estimation, the form of the lip reaction force F is adjusted again to adjust the shape of the side lip 6. In step S9, the adjustment of the shape of the side lip 6 and the confirmation of the torque performance of the basic hub seal 5 or the modified basic hub seal having the adjusted side lip 6 are repeated (step S9) until the torque performance of the basic hub seal 5 or the modified basic hub seal having the re-adjusted side lip 6 satisfies the required torque value set in step S1. Then, in step S9, if it is determined that the torque performance of the basic hub seal 5 with the re-adjusted side lip 6 or the changed basic hub seal satisfies the required torque value set in step S1 ("Yes" in step S9), the process is transferred to the sealing performance confirmation process (step S10).

[0097] In the sealing performance confirmation process (step S10), as described above, the relationship between the foreign matter rejection performance of the basic hub seal 5 or the modified basic hub seal and the torque performance of the basic hub seal 5 or the modified basic hub seal is confirmed to confirm whether the relationship between the foreign matter rejection performance and the torque performance is good. Figure 7 As shown, at each practical speed, when the torque relative to the basic hub seal 5 or the basic hub seal is changed to a foreign body surface position that is considered sufficient, it is judged that the relationship between the foreign body rejection performance and the torque performance is good ("Yes" in step S10).

[0098] On the other hand, in the sealing performance confirmation process (step S10), when the torque relative to the basic hub seal 5 or the changed basic hub seal does not reach the foreign body surface position that is considered sufficient, it is judged that the relationship between the foreign body ejection performance and the torque performance is not good ("No" in step S10). In step S10, if it is judged that the relationship between the foreign body ejection performance and the torque performance is not good, the basic hub seal 5 or the changed basic hub seal is redesigned (step S11) in the same way as steps S4 and S5, the foreign body ejection performance is confirmed (step S12), and the foreign body ejection performance (foreign body surface position at each rotation speed) is adjusted so that the relationship between the foreign body ejection performance and the torque performance becomes good. Then, when it is judged that the foreign body ejection performance is good in step S12, the sealing performance is confirmed again (step S10).

[0099] In addition, in step S10, if it is determined that the relationship between the foreign matter ejection performance and the torque performance is not good, then the shape of the side lip 6 is adjusted (step S13), the torque performance of the basic hub seal 5 or the basic hub seal is changed (step S14), and the torque at each rotation speed of the basic hub seal 5 or the basic hub seal is changed is adjusted in the same way as steps S6 and S7. Then, when it is determined that the torque performance is good in step S14, the sealing performance is confirmed again (step S10). In addition, in step S10, if it is determined that the relationship between the foreign matter ejection performance and the torque performance is not good, the foreign matter ejection performance (foreign matter surface position at each rotation speed) adjustment of the above steps S11 and S12 and the torque at each rotation speed adjustment of the above steps S13 and S14 can also be performed to make the relationship between the foreign matter ejection performance and the torque performance good.

[0100] By performing the processing of steps S10 to S14 in this way, a basic hub seal 5 judged to have a good relationship between foreign matter ejection performance and torque performance is derived or the form of the basic hub seal is changed. Next, if it is judged that the relationship between foreign matter ejection performance and torque performance is good ("Yes" in step S10), the hub seal of the derived form is manufactured as the hub seal 1, and the design of the hub seal 1 is completed (step S15). Then, the hub seal 1 is manufactured (step S16), and the hub seal manufacturing process is terminated.

[0101] Thus, according to the manufacturing method of the hub seal involved in the embodiment of the present invention, it is possible to manufacture the hub seal 1 that reduces the limit of the lip reaction force F of the side lip 4 for maintaining the required sealing performance. Therefore, according to the manufacturing method of the hub seal involved in the embodiment of the present invention, it is possible to manufacture the hub seal 1 that can reduce the limit of the torque of the hub seal 1 for maintaining the required sealing performance.

[0102] The above is an explanation of the embodiments of the present invention, but the present invention is not limited to the hub seal 1 and the manufacturing method of the hub seal 1 involved in the above embodiments of the present invention, and includes all the methods included in the concept and claims of the present invention. In addition, the various structures can be appropriately and selectively combined to achieve at least part of the above-mentioned subjects and effects. For example, the shape, material, configuration, size, etc. of each structure in the above embodiments can be appropriately changed according to the specific use of the present invention.

[0103] For example, the hub seal manufactured by the hub seal manufacturing method according to the present invention is not limited to the hub seal 1 used for inner ring rotating hub bearings, but also includes hub seals used for outer ring rotating hub bearings. Fig.17 1 is a diagram showing a hub seal 7 as another example of a hub seal manufactured by the manufacturing method of a hub seal according to the present invention, and is a cross-sectional view of a cross section along the axis x of the hub seal 7. Hereinafter, regarding the hub seal 7, the same reference numerals as those in the hub seal 1 are assigned to the components having the same or similar functions as those of the hub seal 1, and the description thereof is omitted, and the components different from the hub seal 1 are described.

[0104] Specifically, for example, Fig.17 As shown, the hub seal 7 includes: a seal body 8 as a first sealing component, which is mounted on the outer ring (not shown) on the rotating side of the hub bearing (not shown); and a sleeve 9 as a second sealing component, which is mounted on the inner ring (not shown) on the fixed side of the hub bearing. The seal body 8 and the sleeve 9 are annular components around the axis x, and the seal body 8 has an annular side lip 4 around the axis x. The seal body 8 is different from the above-mentioned seal body 2 and is fixed on the outer peripheral side, and the sleeve 9 is different from the above-mentioned sleeve 3 and is fixed on the inner peripheral side.

[0105] The sleeve 9 has the same cross-sectional shape as the sleeve 3, and has a cylindrical portion 34 corresponding to the cylindrical portion 31 of the sleeve 3 and an annular portion 35 corresponding to the annular portion 32 of the sleeve 3. The cylindrical portion 34 is formed in a shape that is embedded in the inner ring in an interference fit manner so that the sleeve 9 is embedded in the inner ring. The annular portion 35 is formed with a contact surface 36, which is a surface that contacts the side lip 4 when the hub seal 7 is in use. The contact surface 36 is a surface facing the inside of the annular portion 35, and is an annular plane or a substantially plane that extends around the axis x in parallel or substantially parallel to a plane that is orthogonal or substantially orthogonal to the axis x.

[0106] The seal body 8 has a reinforcement ring 13 corresponding to the reinforcement ring 10 of the seal body 2 and an elastic body portion 23 corresponding to the elastic body portion 20 of the seal body 2. The reinforcement ring 13 has the same cross-sectional shape as the reinforcement ring 10, and has a cylindrical portion 14 corresponding to the cylindrical portion 11 of the reinforcement ring 10 and an annular portion 15 corresponding to the annular portion 12 of the reinforcement ring 10. The cylindrical portion 14 is formed in a shape in which the outer ring is embedded in an interference fit manner, so that the reinforcement ring 13 is embedded in the outer ring.

[0107] The elastomer portion 23 has portions corresponding to the base portion 21 and the cylindrical portion 22 of the elastomer portion 20 of the seal body 2, namely, the base portion 24 and the cylindrical portion 25. The base portion 24 is a portion mounted on the inner peripheral side of the annular portion 15 of the reinforcement ring 13, and the cylindrical portion 25 is a portion mounted on the outer peripheral side of the annular portion 15 of the reinforcement ring 13 and the cylindrical portion 14. In addition, the elastomer portion 23 has a sealing lip 26 and a grease lip 27. The sealing lip 26 is used to prevent foreign matter from entering the sealing space S1 and to prevent the lubricant from flowing out of the sealing space S1. In addition, the grease lip 27 is used to prevent the lubricant from flowing out of the sealing space S1. In addition, the hub seal 7 may not have the sealing lip 26. Similarly, the hub seal 7 may not have the grease lip 27.

[0108] The sealing lip 26 extends outward from the inner peripheral end (inner peripheral end 24a) of the base portion 24 located near the inner peripheral end of the annular portion 15 of the reinforcement ring 13, and the grease lip 27 extends inward and inner peripherally from the inner peripheral end 24a of the base portion 24. The sealing lip 26 has the same shape as a known sealing lip, such as Fig.17 As shown in FIG. 1 , the lip front end portion 26a is provided at the front end side. The lip front end portion 26a is, for example, a wedge-shaped portion in cross section, and contacts the outer peripheral surface 34a of the barrel portion 34 of the sleeve 9 in the use state. The grease lip 27 has the same shape as a known grease lip, such as Fig.17 As shown, the lip front end portion 27a contacts the outer peripheral surface 34a of the barrel portion 34 of the sleeve 9 in the use state. In addition, a clamping spring 28 is installed on the sealing lip 26 at a position opposite to the lip front end portion 26a, and the clamping spring 28 applies a tightening force to the sealing lip 26 to push the lip front end portion 26a toward the inner peripheral side, thereby increasing the tightening force pushing the lip front end portion 26a toward the barrel portion 34 of the sleeve 9.

[0109] Furthermore, as described above, the elastic body portion 23 has the side lip 4. In the hub seal 7, as shown in FIG. Fig.17 As shown, the side lip 4 extends outward and peripherally from the base portion 24 of the elastic body portion 23, and the inner peripheral surface 41c of the side lip 4 forms a contact surface 4a for sealing the space between the outer ring and the inner ring. In addition, the side lip 4 is formed so that when the hub seal 7 is in use, the contact surface 4a of the front end portion 41 contacts the contact surface 36 of the sleeve 9 with a predetermined interference.

[0110] The hub seal 7 , like the hub seal 1 , can reduce the limit of reducing the lip reaction force F of the side lip 4 in order to maintain the required sealing performance.

[0111] In addition, the hub seal 7 is provided with a sealing lip 26 and a grease lip 27. In addition to the side lip 4, the sealing lip 26 and the grease lip 27 can also prevent the entry of foreign matter and prevent the outflow of lubricant. In addition, since a clamping spring 28 is installed on the sealing lip 26, the sealing lip 26 increases the tightening force on the barrel 34 of the sleeve 9 through the clamping spring 28. Therefore, when the hub bearing rotates, especially when it rotates at a high speed, it is possible to suppress the sealing lip 26 from leaving the barrel 34 of the sleeve 9, and it is possible to suppress the outflow of lubricant. In this way, the hub seal 7 is formed so that the lubricant is more difficult to flow out.

[0112] In addition, for example, the wheel hub seal according to the present invention can also be applied to an in-wheel motor unit. The in-wheel motor unit is a drive device composed of a wheel hub bearing and an electric motor, which is mounted on a wheel of a vehicle, supplies the motor output to the wheel via the wheel hub bearing to provide power to the wheel, and converts the power of the wheel into electric power via an electric generator to generate electricity.

[0113] Fig.18 2 is a cross-sectional view of an example of an in-wheel motor unit using a hub seal 7. Fig.18 As shown, the in-wheel motor unit 100 includes a hub bearing 60 of an inner ring rotating type, an outer housing 101 as an outer member mounted on the hub bearing 60, an inner housing 102 as an inner member, and a motor generator 103. Specifically, the outer housing 101 is a cylindrical member, and a space is formed to accommodate the inner side of the hub bearing 60. The outer housing 101 is sandwiched between the hub flange 62 of the inner ring 61 of the hub bearing 60 and the brake disc 110 mounted on the hub flange 62, and the wheel is fixed to the inner ring 61 by the hub bolts 63, thereby being fixed between the hub flange 62 and the brake disc 110.

[0114] The inner housing 102 includes: a cylindrical portion 102a, which is a cylindrical component formed with a space on the inner circumference side to accommodate the outer ring 64 of the hub bearing 60; and a disc portion 102b, which is a disc-shaped portion extending from the inner end of the cylindrical portion 102a to the outer circumference side. The cylindrical portion 102a is formed in a shape such that the outer ring 64 is fitted and fixed in the space on the inner circumference side. Fig.18 As shown, the outer shell 101 and the inner shell 102 are formed in a shape in which the inner peripheral surface of the outer shell 101 and the outer peripheral surface of the cylinder 102a of the inner shell 102 are opposed to each other and an annular space is formed between the outer shell 101 and the cylinder 102a. Fig.18As shown, the outer housing 101 and the inner housing 102 are formed in a shape in which the inner end (end 101a) of the outer housing 101 faces the disk portion 102b of the inner housing 102 in the axis Ax direction. An annular gap is formed between the end 101a of the outer housing 101 and the disk portion 102b.

[0115] The motor generator 103 is a cylindrical member extending along the axis Ax and is disposed in an annular space between the outer housing 101 and the cylindrical portion 102a of the inner housing 102. Specifically, the motor generator 103 includes a rotor 104 fixed to the outer housing 101 and a stator 105 fixed to the cylindrical portion 102a of the inner housing 102.

[0116] In the in-wheel motor unit 100, the hub seal 7 is provided to prevent foreign matter from entering the in-wheel motor unit 100 from the annular gap between the end 101a of the outer housing 101 and the circular plate portion 102b of the inner housing 102. Fig.18 As shown, the hub seal 7 is installed between the end 101a of the outer housing 101 and the disc portion 102b of the inner housing 102. Specifically, the sleeve 9 is embedded in the mounting surface 102c of the disc portion 102b of the inner housing 102 in an interference fit manner, and the sleeve 9 is fixed to the disc portion 102b of the inner housing 102. In addition, specifically, the seal body 8 is embedded in the mounting surface 101b of the end 101a of the outer housing 101 in an interference fit manner, and the seal body 8 is fixed to the outer housing 101. In addition, the mounting surface 102c of the disc portion 102b of the inner housing 102 is a cylindrical surface extending along the axis Ax, and the mounting surface 101b of the end 101a of the outer housing 101 is a cylindrical surface extending along the axis Ax. In addition, the mounting surface 101b and the mounting surface 102c are opposite to each other in the radial direction.

[0117] Reference numerals:

[0118] 1, 7 hub seal, 2, 8 seal body, 3, 9 sleeve, 4, 6 side lip, 4a contact surface, 5 basic hub seal, 10, 13 reinforcement ring, 11, 14 cylinder, 12, 15 annular portion, 20, 23 elastic body portion, 21, 24 base portion, 21a inner side surface, 22, 25 cylinder portion, 24a inner peripheral end portion, 26 sealing lip, 26a lip front end portion, 27 grease lip, 27a lip front end portion, 28 clamp spring, 31, 34 cylinder, 32, 35 annular portion, 3 3, 36 contact surface, 34a outer peripheral surface, 41 front end, 41a front end, 41b root end, 41c inner peripheral surface, 41d outer peripheral surface, 41e inner peripheral front end, 41f outer peripheral front end, 41g inner peripheral root end, 41h outer peripheral root end, 42 root, 42a front end, 42b root end, 42c inner peripheral surface, 42d outer peripheral surface, 42e inner peripheral front end, 42f outer peripheral front end, 42g inner peripheral root end, 42h outer peripheral root end, 43, 44 transition part, 43a, 44a inner peripheral transition surface, 43b, 44b outer peripheral transition surface, 50 wheel hub bearing, 50a inner opening, 50b outer opening, 51 outer ring, 51a end, 52 wheel hub, 53 bearing ball, 54 inner ring, 54a end, 54b outer peripheral surface, 55 wheel hub wheel, 55a shaft, 55b wheel mounting flange, 56 retainer, 57 through hole, 58 other sealing device, 59 wheel hub bolt, 60 wheel hub bearing, 61 inner ring, 62 wheel hub flange, 63 wheel hub bolt, 64 outer ring, 100 in-wheel motor unit, 1 01 outer housing, 101a end, 101b mounting surface, 102 inner housing, 102a cylinder, 102b circular plate, 102c mounting surface, 103 electric generator, 104 rotor, 105 stator, 110 brake disc, A sealing surface, c1, c2 extension direction line, F lip reaction force, L1, L2 length, S upstream space, S1 sealing space, T1, T2, T3 thickness, x axis line, V imaginary line, vp1, vp2 imaginary intersection, Z reference position, θ bending angle.

Claims

1. A method for manufacturing a hub seal, wherein the hub seal has a side lip for sealing the space between the outer ring of the hub bearing and the hub, wherein the manufacturing method is characterized in that: A set rotation speed is set, wherein the set rotation speed is a rotation speed at which foreign matter that has intruded into the interior of the hub seal is located at a desired position in a radial direction orthogonal to the axis through rotation around the axis, The shape of the side lip is designed so that the torque of the hub seal at the set speed has a desired value, The hub seal is manufactured to form a hub seal having the designed side lip shape.

2. The method for manufacturing a wheel hub seal according to claim 1, characterized in that: The relationship between the position of a foreign object that has intruded into the interior of a basic hub seal and the rotation speed thereof, which is perpendicular to the axis and is located therein, is obtained. The basic hub seal is a hub seal having a predetermined shape. In the obtained relationship between the position of the foreign matter in the basic hub seal and the rotation speed, it is confirmed whether the position of the foreign matter at the set rotation speed is the desired position.

3. The method for manufacturing a wheel hub seal according to claim 2, characterized in that: Finding the relationship between the position of a foreign object intruding into the interior of a modified basic hub seal due to the rotation about an axis and the rotation speed of the rotation, wherein the modified basic hub seal has a shape obtained by changing the shape of the basic hub seal, In the obtained relationship between the position of the foreign matter in the modified basic hub seal and the rotation speed, it is confirmed whether the position of the foreign matter at the set rotation speed is the desired position.

4. The method for manufacturing a wheel hub seal according to claim 3, characterized in that: The changing of the basic hub seal changes the shape of a space on a side of the basic hub seal that is farther from the space between the outer ring and the hub than a side lip of the basic hub seal.

5. The method for manufacturing a wheel hub seal according to claim 1, characterized in that: The side lip is designed by adjusting at least any one of a thickness of a front end portion of the side lip, a thickness of a root portion of the side lip, and a length of the root portion of the side lip so that the torque of the hub seal at the set rotation speed has the desired value.

6. The method for manufacturing a wheel hub seal according to claim 2, characterized in that: The side lip of the basic hub seal is designed by adjusting at least any one of the thickness of the front end portion of the side lip, the thickness of the root of the basic side lip, and the length of the root of the basic side lip so that the torque of the hub seal at the set speed has the desired value.

7. The method for manufacturing a wheel hub seal according to claim 3, characterized in that: The side lip is designed by adjusting at least any one of the thickness of the front end portion of the side lip of the basic hub seal, the thickness of the root of the basic side lip, and the length of the root of the basic side lip so that the torque of the hub seal at the set speed has the desired value.

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