Method for manufacturing herb seals

Abstract

Even if processing marks remain on the surface where the seal lip contacts, the deterioration of seal performance is suppressed, and disturbance of the rotational torque of the inner side member or the occurrence of noise is suppressed. Based on the value of the rib reaction force (F), which is the value of the reaction force of the side rib (30) in the usage state, divided by the value of the diameter of the hub (52), which is the hub diameter (D), and the value of the surface roughness of the seal surface (31) of the side rib (30), the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) included within the design area, which is the area of ​​the preset rib reaction force (F) / hub diameter (D) and rib surface roughness (R), the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) are selected, and the hub seal is designed such that the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) become the selected rib reaction force (F) / hub diameter (D) and the rib surface roughness (R), and the hub seal is manufactured to become the designed hub seal.

Description

Technology Field

[0001] The present invention relates to a method for manufacturing a hub seal. Background Technology

[0002] In vehicles, such as automobiles, hub bearings that support the wheels to rotate freely are in an environment where they are directly exposed to foreign substances such as rainwater, sewage, and dust. For this reason, hub bearings have conventionally been equipped with hub seals as sealing devices to seal the space formed between the outer ring, which is rotatable relative to the axis, and the hub. These hub seals aim to seal the lubricant inside the hub bearing while also preventing foreign substances from entering the interior. Furthermore, due to demands for fuel efficiency, such hub seals require a reduction or stabilization of the sliding resistance (torque resistance) exerted by the seal lip of the hub seal on the hub bearing. Therefore, there are conventional hub seals that aim to reduce or stabilize torque resistance (see, for example, Patent Document 1). Prior art literature

[0003] Japanese Registered Utility Model Publication No. 3201207 The problem to be solved

[0004] Meanwhile, the outer surface of the hub bearing is formed by machining, and for this reason, machining marks may remain on the outer surface of the hub. Depending on the hub bearing, these machining marks may have a certain directionality; in other words, there may be cases where machining marks are formed on the outer surface of the hub bearing, consisting of multiple traces such as spiral or straight lines around the axis of rotation or groove shapes extending along the axis of rotation. When such machining marks are formed on the outer surface of the hub, depending on the directionality of the machining marks, a pumping action based on the machining marks occurs during the rotation of the hub bearing, causing air or grease within the sealed space formed by adjacent seal lips to be released to the outside of this sealed space. As a result, the pressure within the sealed space becomes lower than atmospheric pressure, creating negative pressure, and the seal lips may be pressed against the outer surface of the hub. Furthermore, due to this negative pressure, disturbances or unusual noises may occur in the rotational torque of the hub bearing.

[0005] In order to prevent disturbances in the rotational torque of the hub bearing or the occurrence of noise, measures to reduce the force with which the seal lip tightens the outer surface of the hub (the tightening force of the seal lip) are considered, but the reduction in the tightening force of the seal lip reduces the seal performance. Therefore, for the hub seal of a conventional hub bearing, a configuration is required that can prevent disturbances in the rotational torque of the hub bearing or the occurrence of noise while preventing a decrease in seal performance.

[0006] The objective of the present invention is to provide a method for manufacturing a hub seal that can suppress the deterioration of seal performance and suppress disturbance of rotational torque of the inner circumferential member or the occurrence of noise even if processing marks remain on the surface where the seal lip contacts. means of solving the problem

[0007] To solve the above problem, a method for manufacturing a hub seal related to the present invention is a method for manufacturing a hub seal having a side lip and intended to seal the space between the outer ring of a hub bearing and the hub, wherein the method comprises selecting the lip reaction force (F) / hub diameter (D) and the lip surface roughness (R) that are included within a design area, which is a preset area of ​​the lip reaction force (F) / hub diameter (D) and the lip surface roughness (R), based on the value obtained by dividing the lip reaction force (F), which is the value of the reaction force of the side lip in the above usage state, by the hub diameter (D), which is the value of the diameter of the hub (lip reaction force (F) / hub diameter (D)), and the lip surface roughness (R), which is the value of the surface roughness of the seal surface, which is the surface roughness of the side lip contacting the hub, and wherein the lip reaction force (F) / hub diameter (D) and the lip surface roughness (R) are such that the selected lip reaction force (F) / hub diameter (D) and the rib surface roughness (R) are designed to have the hub seal, and the hub seal is manufactured to have the designed hub seal. The design area is a torque disturbance area, which is a region of the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) that is preset based on the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R), and a seal performance degradation area, which is a region of the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) that is preset based on the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R). The torque disturbance area is a region where torque disturbance is expected to occur, and the seal performance degradation area is a region where seal performance is expected to degrade.

[0008] In a method for manufacturing a hub seal related to one aspect of the present invention, the rib reaction force (F) is determined based on at least one of the angle of the extension direction of the side rib with respect to the direction perpendicular to the axis of the hub seal, the length of the extension direction of the side rib, the thickness of the direction perpendicular to the extension direction of the side rib, and the shape of the base of the side rib.

[0009] In a method for manufacturing a hub seal related to one embodiment of the present invention, the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) are selected within a target area, which is a preset area within the design area.

[0010] In a method for manufacturing a hub seal related to one embodiment of the present invention, the range of the rib reaction force (F) / hub diameter (D) in the target area is 0.05 N / mm or more and 0.09 N / mm or less, and the range of the rib surface roughness (R) in the target area is within the range of RzJIS 10㎛-α or more and RzJIS 10㎛+α or less, and α is a tolerance during the molding of the side rib.

[0011] In a method for manufacturing a hub seal related to one embodiment of the present invention, the side lip having the selected lip reaction force (F) / hub diameter (D) and the lip surface roughness (R) is determined to be formed in the hub bearing, and the lip reaction force (F) / hub diameter (D) and the lip surface roughness (R) are selected. Effects of the invention

[0012] According to the method for manufacturing a hub seal related to the present invention, even if processing marks remain on the surface where the seal lip contacts, the deterioration of seal performance can be suppressed, and disturbance of the rotational torque of the inner circumferential member or the occurrence of noise can be suppressed. Brief explanation of the drawing

[0013] FIG. 1 is a cross-sectional view along an axis to show a schematic configuration of a hub seal related to an embodiment of the present invention. FIG. 2 is a partially enlarged cross-sectional view showing the vicinity of the side lip, middle lip, and main lip of the hub seal shown in FIG. 1. FIG. 3 is a cross-sectional view of a hub bearing in a cross-section along an axis to show the usage state of a hub seal mounted on the hub bearing. Figure 4 is a partially enlarged cross-sectional view of the vicinity of the hub seal in Figure 3. Figure 5 is an enlarged view of a side lip to explain the factors affecting the lip reaction force of the side lip shown in Figure 2. FIG. 6 is a diagram showing the schematic configuration of a reaction force measuring device for measuring the reaction force of the side lip of a hub seal related to a test example. Figure 7 is a diagram showing the schematic configuration of a test apparatus for conducting an evaluation test of a hub seal related to a test example. Figure 8 is a graph showing the relationship between the value of the lip reaction force per unit length of the side lip of the hub seal related to the test example and the lip surface roughness. Figure 9 is a diagram showing another graph representing the relationship between the value of the lip reaction force per unit length of the side lip of the hub seal related to the test example and the lip surface roughness. FIG. 10 is a diagram showing a flowchart of a method for manufacturing a hub seal related to an embodiment of the present invention. FIG. 11 is a diagram showing a flowchart of the process of creating side lip design standard data referenced in the hub seal manufacturing process of FIG. 10. FIG. 12 is a flowchart of a side lip element selection process for selecting a combination of "lip reaction force (F) / hub diameter (D)" and lip surface roughness (R) in the hub seal manufacturing process shown in FIG. 10. FIG. 13 is a diagram showing a flowchart of a conventional method for manufacturing a hub seal. Specific details for implementing the invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0015] FIG. 1 is a cross-sectional view along the axis (x) of a hub seal (1) according to an embodiment of the present invention, manufactured by the method for manufacturing a hub seal according to the present invention. The hub seal manufactured by the method for manufacturing a hub seal according to the present invention has a side lip and is a hub seal intended to seal the space between an outer circumferential member and an inner circumferential member that is at least partially surrounded by the outer circumferential member and is rotatable relative to the outer circumferential member. The hub seal (1) according to an embodiment of the present invention is specifically used in a hub bearing (50), as described below, and is used to seal the space between an outer ring (51) as an outer circumferential member rotatable relative to the axis and a hub (52) as an inner circumferential member (see FIG. 3).

[0016] For convenience of explanation, the side in the direction of arrow a (see FIG. 1) in the axis (x) direction (one side in the axis direction) is designated as the outer side, and the side in the direction of arrow b (see FIG. 1) in the axis (x) direction (the other side in the axis direction) is designated as the inner side. More specifically, the outer side is the side in the direction away from the space between the outer ring (51) and the hub (52), which is the space to be sealed, in the axis (x) direction, and the inner side is the side in the direction approaching the space to be sealed in the axis (x) direction. In addition, in the direction perpendicular to the axis (x) (hereinafter also referred to as the "diameter direction"), the side in the direction away from the axis (x) (direction of arrow c in FIG. 1) is designated as the outer circumference side, and the side in the direction approaching the axis (x) (direction of arrow d in FIG. 1) is designated as the inner circumference side. Also, the axis (x) is an imaginary line.

[0017] As shown in FIG. 1, the hub seal (1) has a ring-shaped reinforcing ring (10) around the axis (x) and an elastic body part (20) formed as a ring-shaped elastic body around the axis (x) and mounted on the reinforcing ring (10). The elastic body part (20) has a side lip (30), an intermediate lip (21), and a main lip (22). The side lip (30) is a seal lip that extends outward (in the direction of arrow a) and is formed to contact the hub (52) from the inside (in the direction of arrow b) when the hub seal (1) described later is mounted on the hub bearing (50) in a state of use. The intermediate lip (21) is a seal lip that extends outward from the inner side of the side lip (30) and is formed to contact the hub (52) from the inner side in the state of use. The main lip (22) is a seal lip that is formed to contact the hub (52) from the outer side in the state of use. The side lip (30) is shaped to suppress torque disturbance of the hub (52) and degradation of the seal performance of the side lip (30), and the shape of the side lip (30) is based on the value of the reaction force of the side lip (30) in use (lip reaction force (F)) divided by the value of the diameter of the hub (52) (hub diameter (D)) (lip reaction force (F) / hub diameter (D)) and the value of the surface roughness of the seal surface (31), which is the surface of the side lip (30) that contacts the hub (52) (lip surface roughness (R)). Below, the hub seal (1) will be described in detail.

[0018] The reinforcing ring (10) is a ring-shaped metal member having an axis (x) as the central axis or approximately central axis, as shown in FIG. 1, for example, and is formed to be pressed into and fitted into a through hole of the outer ring (51) of the hub bearing (50) described later, and by pressing the reinforcing ring (10) into the outer ring (51), the hub seal (1) is fixed to the outer ring (51). The reinforcing ring (10) has a tubular fitting part (11), a position adjustment part (12) that is bent inward from the inner end of the fitting part (11) and extends outward, and a flange part (13) that is circular or approximately circular and extends outward from the outer end of the fitting part (11).

[0019] The fitting portion (11) is, for example, a cylindrical or approximately cylindrical part with the axis (x) as the central axis or approximately central axis, and is formed such that, on the outer surface (11a) which is the circumferential surface on the outer side, it is pressed into the outer opening (51a) of the outer ring (51) and fitted into the inner surface thereof as described below. The position adjustment portion (12) is shaped such that the side lip (30), the intermediate lip (21), and the main lip (22) are positioned at a desired location on the hub seal (1). The position adjustment portion (12) has a return portion (12a), a connecting flange portion (12b), a return portion (12c), and a lip flange portion (12d), for example as shown in FIG. 1. The return portion (12a) is, for example, a portion having a roughly conical or roughly cylindrical shape that bends outward from the inner end of the fitting portion (11). The connecting flange portion (12b) is, for example, a circular or roughly circular portion extending inward from the outer end of the return portion (12a). The return portion (12c) is, for example, a conical or roughly conical portion extending obliquely inward and inward from the inner end of the connecting flange portion (12b). The lip flange portion (12d) is, for example, a circular or roughly circular portion extending inward from the inner end of the return portion (12c). The flange portion (13) is a circular or approximately circular portion that extends in the diameter direction with the axis (x) as the center or approximately center, as shown in FIG. 1, for example. The reinforcing ring (10) is formed as a single member by press processing or forging from a metal plate, and the fitting portion (11), the positioning portion (12), and the flange portion (13) are each part of the reinforcing ring (10) formed integrally from the same material and are integrally continuous.As for the metal material of the reinforcing ring (10), for example, stainless steel or SPCC (cold-rolled steel) are used.

[0020] The elastic body (20) is mounted on the reinforcing ring (10) as described above, and is formed integrally with the reinforcing ring (10) to cover the reinforcing ring (10) from the outside, for example, as shown in FIG. 1. The elastic body (20) has, for example, a base body (23). The base body (23) is a part that supports the side lip (30), the intermediate lip (21), and the main lip (22), and the side lip (30), the intermediate lip (21), and the main lip (22) each extend from the base body (23). The intermediate lip (21) and the main lip (22) are each extended from, for example, the inner end of the body portion (23), and the side lip (30) is, for example, extended from the body portion (23) by being radially separated from the intermediate lip (21) at the outer end of the intermediate lip (21). The body portion (23) is extended on the outer surface of the reinforcing ring (10) over, for example, the flange portion (13), the fitting portion (11), and the position adjustment portion (12) of the reinforcing ring (10).

[0021] FIG. 2 is a partial enlarged cross-sectional view showing the vicinity of the side lip (30), middle lip (21), and main lip (22) of the hub seal (1). As shown in FIG. 1 and 2, the side lip (30) extends outwardly from the body portion (23) in a ring shape with the axis (x) as the central axis or approximately central axis, and is formed so that the tip of the seal surface (31) contacts the hub (52) with a predetermined tightening margin in the usage state of the hub seal (1) described later. The side lip (30) has a conical or approximately conical shape in which the diameter increases as it extends outward in the direction of the axis (x), for example.

[0022] As shown in FIGS. 1 and 2, the intermediate lip (21) is extended outwardly from the body portion (23) in a ring shape with the axis (x) as the central axis or approximately the central axis, and is formed so that, in the usage state of the hub seal (1) described later, the tip of the seal surface (21a) contacts the hub (52) with a predetermined tightening margin. The intermediate lip (21) has a conical or approximately conical shape in which the diameter increases as it extends outward in the direction of the axis (x), for example. The intermediate lip (21) may be extended outwardly parallel to the side lip (30), or, as shown in FIGS. 1 and 2, may have a gentler slope with respect to the axis (x) than the side lip (30). It may also be the opposite. The main lip (22) is extended in a ring shape from the body part (23) toward the inside and inner circumference, with the axis (x) as the central axis or approximately the central axis, as shown in FIG. 1 and 2, for example. The main lip (22) is formed so that, in the use state of the hub seal (1) described later, the tip of the seal surface (22a) contacts the hub (52) from the outer circumference with a predetermined tightening margin. Grease (not shown) as a lubricant is applied to each of the seal surface (31) of the side lip (30), the seal surface (21a) of the intermediate lip (21), and the seal surface (22a) of the main lip (22). Also, the sealing surface (31) of the side lip (30), the sealing surface (21a) of the middle lip (21), and the sealing surface (22a) of the main lip (22) are each surfaces facing the inner side of the side lip (30), middle lip (21), and main lip (22).

[0023] The tightening margin of the seal lip is the length of the free state seal lip, which is not deformed by external force, protruding beyond the contact surface that the seal lip contacts in the usage state. Specifically, the tightening margin of the side lip (30) is the length in the axial (x) direction of the portion of the seal surface (31) that protrudes beyond the surface of the hub (52) (inner circumferential surface (55d) of the wheel mounting flange (55b)), which is the contact surface indicated by the dashed line (V) in FIG. 2. Additionally, the tightening margin of the intermediate lip (21) is the length in the axial (x) direction of the portion of the seal surface (21a) that protrudes beyond the contact surface of the hub (52) (transition part (55c) of the wheel mounting flange (55b)), which is the contact surface indicated by the dashed line (V). Additionally, the tightening margin of the main lip (22) is the diameter of the portion of the seal surface (22a) that protrudes beyond the contact surface (outer circumference (55e) of the shaft portion (55a)) of the hub (52) represented by the virtual line (V).

[0024] Additionally, the elastic body part (20) has an outer ring projection (24) formed thereon, for example, as shown in FIG. 1. The outer ring projection (24) is a ring-shaped projection formed on the outer side of the side lip (30) and protruding outwardly around an axis (x), and is formed to form a ring-shaped gap between the hub (52) and the outer end (24a), which is the outer tip, in the usage state described later. The outer ring projection (24) protrudes outward from the outer end of the body part (23), for example, and extends in a conical or approximately conical shape with the axis (x) as the central axis or approximately central axis.

[0025] Additionally, the elastic body (20) has a ring-shaped section (25) that protrudes outward toward the outer side of the outer ring projection (24), as shown in FIG. 1, for example. The embankment section (25) is formed to protrude outward toward the outer side of the outer ring (51) when the hub seal (1) is mounted on the outer ring (51), as described later. The embankment section (25) is formed to cover the outer end of the flange section (13) of the reinforcing ring (10), as shown in FIG. 1, for example. Additionally, the elastic body (20) has a gasket section (26) that at least partially covers the inner surface of the flange section (13) of the reinforcing ring (10), as shown in FIG. 1. The gasket portion (26) is extended in a ring shape around the axis (x) and is connected to the end of the inner side of the embankment portion (25).

[0026] The elastic body (20) is integrally mounted on the reinforcing ring (10), and the side lip (30), intermediate lip (21), main lip (22), gasket part (23), outer ring protrusion (24), embankment part (25), and gasket part (26) described above are integrally continuous as each part of the elastic body (20) formed integrally from the same material. As the elastic body of the elastic body (20), there are, for example, various rubber materials. Various rubber materials are synthetic rubbers such as, for example, nitrile rubber (NBR), hydrogenated nitrile rubber (H-NBR), acrylic rubber (ACM), and fluororubber (FKM).

[0027] Also, the shape of the reinforcing ring (10) is not limited to the shape described above and may have a different shape. The reinforcing ring (10) may have the shape of a known hub seal reinforcing ring having, for example, a side lip, an intermediate lip, and a main lip. For example, the reinforcing ring (10) may not have a flange portion (13). Also, the shape of the elastic body portion (20) is not limited to the shape described above and may have a different shape. The elastic body portion (20) may have the shape of a known hub seal elastic body portion having, for example, a side lip, an intermediate lip, and a main lip. For example, the elastic body portion (20) may not have an outer ring projection (24). Also, for example, the elastic body portion (20) may not have a dike portion (25).

[0028] FIG. 3 is a cross-sectional view of a hub bearing (50) along an axis (x) to show the usage state of a hub seal (1) mounted on a hub bearing (50) (hereinafter simply referred to as "cross-section"), and FIG. 4 is a partially enlarged cross-sectional view of the vicinity of the hub seal (1) in FIG. 3. Also, in the illustrated example, the axis of the hub bearing (50) coincides or nearly coincides with the axis (x) of the hub seal (1). As shown in FIG. 3, the hub bearing (50) is a conventionally known hub bearing formed in a vehicle such as an automobile, and supports the wheel so that it can rotate freely in an axle or suspension system. The hub bearing (50) specifically comprises, as shown in FIG. 3, an outer ring (51) having an axis (x) as an outer circumferential member as a central axis or approximately central axis, a hub (52) as an inner circumferential member that is rotatable relative to the outer ring (51) and partially surrounded by the outer ring (51) as a central axis or approximately central axis, and a plurality of bearing balls (53) formed and arranged between the outer ring (51) and the hub (52). In the usage state of the hub bearing (50) mounted on a vehicle, etc., the outer ring (51) is fixed and the hub (52) is rotatable relative to the outer ring (51). The hub (52) specifically has an inner ring (54) and a hub ring (55), and the hub ring (55) has a cylindrical or approximately cylindrical shaft portion (55a) extending along an axis (x) and a wheel mounting flange (55b). The wheel mounting flange (55b) is a disc-shaped portion extending outward from one end of the shaft portion (55a) and is a portion on which a wheel not shown is mounted by a plurality of hub bolts.The shaft portion (55a) and the wheel mounting flange (55b) are smoothly connected on the inner side, and the transition portion (55c), which is the part where the shaft portion (55a) and the wheel mounting flange (55b) are connected on the inner side, has a contour that forms a smooth curve in the shape of an arc or a curve in the cross-section along the axis (x). The inner ring (54) is fitted into the inner end of the shaft portion (55a) of the hub ring (55) to hold the bearing ball (53) in the space between the outer ring (51) and the inner ring (54). In the space between the outer ring (51) and the hub (52), the bearing ball (53) is held by a retainer (56).

[0029] The outer ring (51) has a through hole (57) extending in the direction of the axis (x), and the shaft portion (55a) of the hub ring (55) of the hub (52) is inserted into the through hole (57), and a ring-shaped space extending along the axis (x) is formed between the shaft portion (55a) and the through hole (57). In this space, a bearing ball (53) is received as described above and is held by a retainer (56), and a lubricant is applied or injected. A hub seal (1) is mounted on the outer opening (51a) of the outer ring (51), which forms an open opening in the space between the shaft portion (55a) and the through hole (57), and another sealing device (58) is mounted on the inner opening (51b) of the outer ring (51), which forms an open opening in the space between the shaft portion (55a) and the through hole (57). By the hub seal (1) and the sealing device (58), the space between the shaft portion (55a), the inner ring (54), and the through hole (57) is sealed, preventing the internal lubricant from leaking out, and preventing foreign substances such as rainwater, sewage, or dust from entering the interior from the outside. The sealing device (58) is a conventionally known sealing device, and a detailed description is omitted. In addition, a hub seal (1) may be applied as a sealing device (58). The configuration of the hub bearing to which the hub seal (1) is applied is not limited to the configuration of the hub bearing (50) described above.

[0030] As shown in FIGS. 3 and 4, the hub seal (1) is mounted on the outer opening (51a) of the outer ring (51). Specifically, the hub seal (1) is fixed to the outer ring (51) by the fitting portion (11) of the reinforcing ring (10) being pressed into the outer opening (51a) of the outer ring (51). The outer surface (11a) of the fitting portion (11) of the reinforcing ring (10) is in contact with the inner surface (51c) of the outer opening (51a) of the outer ring (51), and a seal is achieved between the reinforcing ring (10) and the outer ring (51). In addition, in the state of use, as shown in FIG. 3 and 4, the reinforcing ring (10) is mounted on the outer ring (51) such that its flange portion (13) presses the gasket portion (26) of the elastic body portion (20) that expands inward against the outer cross-section (51d) which forms a ring-shaped surface facing outward from the outer opening (51a). Accordingly, the gasket portion (26) is compressed between the outer cross-section (51d) and the flange portion (13), thereby improving the sealing performance between the outer ring (51) and the hub seal (1). In addition, the entry of foreign matter is also prevented by the outer ring protrusion (24) or the embankment portion (25) of the elastic body portion (20).

[0031] In the state of use, the front end of the sealing surface (31) of the side lip (30) is slidably in contact with the surface of the hub wheel (55), for example, the inner side (inner side (55d)) of the wheel mounting flange (55b), at a portion (contact width) corresponding to the predetermined tightening margin described above. Additionally, the front end of the intermediate lip (21) is slidably in contact with the surface of the hub wheel (55), for example, the transition portion (55c), at a portion (contact width) corresponding to the predetermined tightening margin described above. In addition, the tip of the main lip (22) is slidably in contact with the surface of the hub wheel (55), for example, the outer surface (55e) which is the outer circumference side of the shaft portion (55a), at a portion (contact width) corresponding to the predetermined tightening margin described above. The side lip (30) and the intermediate lip (21) prevent foreign matter from entering the through hole (57), and the main lip (22) prevents the lubricant from leaking out of the through hole (57).

[0032] As described above, in the hub seal (1), grease is applied to the seal surface (31) of the side lip (30), the seal surface (21a) of the intermediate lip (21), and the seal surface (22a) of the main lip (22). Thus, in the state of use, as shown in FIG. 4, grease (G) is interposed between the respective contact surfaces of the side lip (30) and the inner surface (55d) of the wheel mounting flange (55b). Likewise, grease (G) is interposed between the respective contact surfaces of the intermediate lip (21) and the transition portion (55c) of the wheel mounting flange (55b), and grease (G) is also interposed between the respective contact surfaces of the main lip (22) and the outer surface (55e) of the shaft portion (55a).

[0033] There may be a case where a machining mark formed by machining during the manufacture of the hub bearing (50) remains on the inner surface (55d) of the wheel mounting flange (55b) of the hub wheel (55) that the side lip (30) contacts. If this machining mark forms, for example, a groove with a certain directionality, and depending on the degree of surface roughness of this machining mark, a pumping action may occur based on this machining mark when the hub (52) rotates. Due to this pumping action, air or grease (G), etc., within the space (S) surrounded by the side lip (30), the wheel mounting flange (55b) of the hub wheel (55), the intermediate lip (21), and the gas section (23) are discharged from the space (S) to the outside, and the pressure within the space (S) is lowered compared to the pressure of the outside atmosphere, so that the space (S) becomes negative pressure. When the space (S) becomes negative pressure, the side lip (30) is pulled toward the wheel mounting flange (55b), and the side lip (30) is additionally pressed against the inner surface (55d) of the wheel mounting flange (55b). As a result, disturbance or noise may occur in the rotational torque of the hub (52).

[0034] The inventors have carefully investigated the relationship between the occurrence of rotational torque disturbance of the hub (52) described above (hereinafter also referred to as "torque disturbance"), the rib reaction force (F) of the side lip (30), and the rib surface roughness (R) of the sealing surface (31) of the side lip (30), and have found that there is a relationship between the occurrence of torque disturbance of the hub (52), the rib reaction force (F) of the side lip (30), the hub diameter (D) of the hub (52), and the rib surface roughness (R) of the sealing surface (31) of the side lip (30). In addition, it was found that there is a relationship between the degradation of the seal performance of the side lip (30), the lip reaction force (F) of the side lip (30), the hub diameter (D) of the hub (52), and the lip surface roughness (R) of the seal surface (31) of the side lip (30). The present invention is based on this finding. Below, the hub seal and the method of manufacturing the hub seal related to this finding and the present invention based on this finding will be described. Also, the hub diameter (D) of the hub (52) is the diameter of the part of the hub ring (55) to which the diameter direction dimension of the hub seal (1) is related. The hub diameter (D) of the hub (52) is, for example, the diameter of the part of the hub ring (55) to which the diameter dimension of the side lip (30) is related. Specifically, for example, the hub diameter (D) is the diameter of the outer surface (55e) of the shaft portion (55a) of the hub wheel (55) or the diameter of the transition portion (55c) of the wheel mounting flange (55b) of the hub wheel (55).

[0035] The inventors presumed that the disturbance in the rotational torque of the hub or noise that occurs when negative pressure is generated in the space formed by the side lip (see space (S)) during the use of the hub seal is caused by the fact that a grease film is not formed on the contact surface (sliding surface) of the seal surface of the side lip, causing the contact surface of the side lip to intermittently catch on the sliding hub, resulting in stick-slip. Furthermore, they presumed that the reason a grease film is not formed on the contact surface (sliding surface) of the seal surface of the side lip is related to the magnitude of the reaction force of the side lip and the magnitude of the surface roughness of the seal surface of the side lip. Therefore, the inventors manufactured multiple hub seals (1) in which the value of the lip reaction force (F) of the side lip (30) and the value of the lip surface roughness (R) of the seal surface (31) of the side lip (30) were different, and conducted an evaluation test to confirm the occurrence of torque disturbance of the hub and the degradation of seal performance on the multiple hub seals (1) manufactured.

[0036] <Test Example> The lip reaction force (F) of the side lip (30) is an axial (x) direction force that the side lip (30) applies to the inner surface (55d) of the wheel mounting flange (55b) of the hub wheel (55) in the state of use of the hub seal (1), as shown in FIG. 4. The elements of the side lip (30) that determine the lip reaction force (F) of the side lip (30) include, as an example shown in FIG. 5, the angle (lip angle (A)) of the extension direction (e) of the side lip (30) relative to the diameter direction, the length (lip length (L)) of the side lip (30) in the extension direction, the thickness (lip thickness (DL)) in the direction perpendicular to the extension direction of the side lip (30), and the shape of the source of the side lip (30).

[0037] As shown in FIG. 5, the elements of these side ribs (30) are values ​​in a cross-section along the axis (x) of the side ribs (30). The extension direction (e) of the side ribs (30) is the direction in which the contour of the seal surface (31) in the cross-section of the side ribs (30) extends. Also, the contour of the seal surface (31) in the cross-section of the side ribs (30) is a straight line or approximately a straight line. Additionally, the rib length (L) is the length of the contour of the seal surface (31) in the cross-section of the side ribs (30), as shown in FIG. 5, and is the length between the leading edge (seal surface leading edge (32)) of the seal surface (31) of the side ribs (30) and the root end (seal surface root end (33)) of the seal surface (31) of the side ribs (30). Additionally, the lip thickness (DL) of the side lip (30) is constant along the extension direction of the side lip (30) and is the gap between the outer surface (34), which is the surface facing the outer circumference of the side lip (30), and the seal surface (31). Also, the contour of the outer surface (34) in the cross-section of the side lip (30) is a straight line or approximately a straight line. Additionally, the lip thickness (DL) of the side lip (30) does not have to be constant along the extension direction of the side lip (30), for example, it may be nearly constant along the extension direction of the side lip (30) or may have a tapered shape.

[0038] As shown in FIG. 2 and 5, the side lip (30) has a lip tip (35) and a lip base (36), and the shape of the lip base (30), which is a factor determining the lip reaction force (F) of the side lip (30), is the shape or dimension of a specific part of the lip base (36). The outer surface (36a) of the lip base (36) is formed as a curved surface so as to be smoothly connected to, for example, the body part (23), and as shown in FIG. 5, the outer surface (36a) of the lip base (36) forms a curve that is convex toward the inner circumference in cross-section. Additionally, the inner surface (36b) of the lip base (36) is a cylindrical surface or approximately cylindrical surface that extends mainly along the axis (x), as shown in FIG. 5, and both ends of the inner surface (36b) are curved and are smoothly connected to the seal surface (31) and the body part (23), respectively. The shape of the lip base (30), which is a factor determining the lip reaction force (F) of the side lip (30), specifically is, for example, the lip thickness (DLb) in the diameter direction of the lip base (36), the curvature of the outer surface (36a), the curvature of both ends of the inner surface (36b), etc. In addition, if the inner surface (36b) is a curved surface, the curvature of the inner surface (36b) also becomes the shape of the source of the side lip (30), which is a factor determining the lip reaction force (F) of the side lip (30). Also, the lip tip portion (35) is a portion surrounded by the seal surface (31), the outer surface (34), and the seal tip edge (37), and the lip base portion (36) is a portion connected to the body portion (23) and is a portion between the lip tip portion (35) and the body portion (23). Also, the diameter-direction thickness (DLb) of the lip base portion (36) is the diameter-direction thickness at the innermost position of the outer surface (36a) of the lip base portion (36), for example, as shown in FIG. 5.Also, the virtual line (B1) in FIG. 5 is a virtual boundary line between the tip of the lip (35) and the base of the lip (36), and the virtual line (B2) in FIG. 5 is a virtual boundary line between the base of the lip (36) and the body (23).

[0039] As a test example for conducting the above evaluation test, 25 hub seals (1) with different rib reaction forces (F) were manufactured (Test Examples 1 to 25). By setting the rib angle (A), rib thickness (DL), rib length (L), and the shape of the rib base (36), which are elements of the side rib (30) determining the rib reaction force (F) described above, to various values ​​or shapes, the rib reaction forces (F) of Test Examples 1 to 25 were made to have different rib reaction forces (F). In addition, the parts other than the side rib (30) of Test Examples 1 to 25 were made identical to each other. However, differences such as manufacturing deviations between the parts other than the side rib (30) of Test Examples 1 to 25 were allowed.

[0040] The measurement of the rib reaction force (F) of Test Examples 1 to 25 was performed using the reaction force measuring device (E1) shown in FIG. 6. Specifically, the hub seal (1) (Test Examples 1 to 25) was fixed to the lower arm (E3), and a load cell (E5) with a disc (E4) mounted on it was mounted on the upper arm (E2). The upper arm (E2) was moved toward the lower arm (E3) to bring the disc (E4) into contact with the side rib (30) of the hub seal (1). At this time, the force received by the disc (E4) from the side rib (30) was measured by the load cell (E5), and the rib reaction force (F) was measured. In addition, the hub seal (1) was fixed to the lower arm (E3) in a position where the side rib (30) was toward the upper arm (E2). In addition, the measured rib reaction force (F) was defined as the rib reaction force (F) when the contact width of the side rib (30) with respect to the disc (E4) corresponds to the width of the tightening margin of the side rib (30) in the usage state of the hub seal (1).

[0041] <Evaluation Test>

[0042] Evaluation tests were conducted on the above-described Test Examples 1 to 25. The evaluation tests were conducted using the test device (E10) shown in FIG. 7. The test device (E10) has a rotating shaft (E11) that can rotate around an axis, and a hub analog (E12) is mounted on the tip of the rotating shaft (E11). The hub analog (E12) has a surface (E13) with the same shape as the inner surface (55d) and transition portion (55c) of the wheel mounting flange (55b) of the hub wheel (55) and the outer surface (55e) of the shaft portion (55a) of the hub wheel (55), where the side lip (30), intermediate lip (21), and main lip (22) come into contact in the usage state of the hub seal (1) shown in FIG. 4. Additionally, the test device (E10) has an outer ring analogue (E14), and the outer ring analogue (14) has a fixing part (E15) which is a part with the same shape as the outer opening (51a) of the outer ring (51) into which the reinforcing ring (10) is pressed in during the use state of the hub seal (1) shown in FIG. 4. In short, the fixing part (15) has a surface with the same shape as the inner circumferential surface (51c) and the outer cross-section (51d) of the outer opening (51a) of the outer ring (51). The hub seal (1) is mounted between this outer ring analogue (E14) and the hub analogue (E12). Specifically, a reinforcing ring (10) is pressed into the fixed part (E15) of the outer ring analogue (E14), and the side lip (30), middle lip (21), and main lip (22) come into contact with the surface (E13) of the hub analogue (E12).At this time, the contact width to the surface (E13) of the side lip (30) is set to a width corresponding to the tightening margin of the side lip (30) in the usage state of the hub seal (1), the contact width to the surface (E13) of the intermediate lip (21) is set to a width corresponding to the tightening margin of the intermediate lip (21) in the usage state of the hub seal (1), and the contact width to the surface (E13) of the main lip (22) is set to a width corresponding to the tightening margin of the main lip (22) in the usage state of the hub seal (1). Accordingly, the interior of the test device (E10) is sealed. In the test device (E10), a sealing head (E16) is formed on the outside of the outer ring analogue (E14) and the hub analogue (E12) to form a sealed space for storing wastewater, and wastewater is sealed inside the sealing head (E16). Additionally, a leak sensor (E17) is mounted on the inner surface of the outer ring analogue (E14) at a location near the hub seal (1). The leak sensor (E17) detects the leaked wastewater when it leaks inward beyond the hub seal (1). Furthermore, the wastewater leaked beyond the hub seal (1) is collected on the lower part of the inner surface of the outer ring analogue (E14) and at a location near the hub seal (1). Additionally, the torque of the rotating shaft (E11) is detected using a torque measuring instrument (E18). For example, a torque measuring instrument (E18) detects the torque of the rotating shaft (E11) at a predetermined period.

[0043] After the test time has elapsed, the detection result of the leak sensor (E17) was checked, and it was determined whether the leak sensor (E17) operated during the test. If the leak sensor (E17) operated during the test, it was determined that there was a leak of wastewater and evaluated as a degradation of seal performance. In addition, if the detection value of the torque measuring instrument (E18) or the calculated value based on this detection value is greater than a predetermined threshold value, it was determined that there is a torque disturbance. The presence or absence of a torque disturbance is determined, for example, by storing the detection value of the torque measuring instrument (E18) detected during a predetermined test time, and calculating how much the detection value detected during the stored predetermined test time or the calculated value based on these detection values ​​deviates from a predetermined threshold value. For example, during a predetermined torque measurement time, a ratio (torque stability) of torque detection values ​​or calculated values ​​that are smaller than a predetermined threshold value is calculated among the torque detection values ​​detected by the torque measuring instrument (E18) at a predetermined sampling period or calculated values ​​based on these torque detection values. If this ratio (torque stability) is less than or equal to another predetermined threshold value, it is determined that there is a torque disturbance. Additionally, an average value of the torque detection values ​​detected by the torque measuring instrument (E18) at a predetermined sampling period or calculated values ​​based on these torque detection values ​​may be calculated, and the presence or absence of a torque disturbance may be determined by comparing this average value with another predetermined threshold value. The calculated value based on the torque detection values ​​is, for example, the standard deviation of the torque detection values ​​detected by the torque measuring instrument (E18) at a predetermined sampling period. The method for determining the presence or absence of a torque disturbance described above is an example, and the presence or absence of a torque disturbance may be determined by other methods.

[0044] The evaluation test results of Test Examples 1 to 25 are shown in the graph of FIG. 8. In addition, the value of the rib reaction force (F) per unit length of each side rib (30) of Test Examples 1 to 25 and the rib surface roughness (R) of the side rib (30) are shown in the graph of FIG. 8. In addition, the relationship between the value of the rib reaction force (F) per unit length of the side rib (30) of Test Examples 1 to 25 and the rib surface roughness (R) of the side rib (30) is shown in the graph of FIG. 8. Also, the value of the rib reaction force (F) per unit length of the side rib (30) is the value obtained by dividing the rib reaction force (F) of the side rib (30) by the value of the diameter of the part corresponding to the outer circumference (55e) of the shaft portion (55a) of the hub wheel (55) on the surface (E13) of the hub analog (E12) (rib reaction force (F) / hub analog diameter (DE)). Also, the hub analog diameter (DE) is a value corresponding to the hub diameter (D). In the graph of FIG. 8, the value of the rib reaction force (F) / hub analog diameter (DE) for each test example 1 to 25 is plotted on the horizontal axis, and the value of the rib surface roughness (R) for each test example 1 to 25 is plotted on the vertical axis. Also, in FIG. 8, the white circle is a plot corresponding to a test example in which no torque disturbance occurred, and the black circle is a plot corresponding to a test example in which torque disturbance occurred.

[0045] From the results of this evaluation test, it can be seen that a torque disturbance area can be established as shown in FIG. 8, and also that a seal performance degradation area can be established. The torque disturbance area is an area where torque disturbance is expected to occur, and a side lip (30) with a value within the torque disturbance area can be determined to be a side lip (30) where torque disturbance occurs. Additionally, the seal performance degradation area is an area where seal performance is expected to degrade, and a side lip (30) with a value within the seal performance degradation area can be determined to be a side lip (30) where sewage leaks and seal performance degrades. If the value of the lip reaction force (F) is small, the seal performance degrades, and if the value of the lip surface roughness (R) is large, the seal performance degrades.

[0046] As such, from the results of this evaluation test, it can be seen that there is a relationship between the value per unit length of the rib reaction force (F) of the side lip (30) (rib reaction force (F) / hub analog diameter (DE)) and the rib surface roughness (R) of the side lip (30) and the occurrence of torque disturbance, and also that there is a relationship between the value per unit length of the rib reaction force (F) of the side lip (30) and the rib surface roughness (R) of the side lip (30) and the deterioration of seal performance. In addition, it can be seen that a region in which torque disturbance occurs can be set with respect to the value per unit length of the rib reaction force (F) of the side rib (30) and the value of the rib surface roughness (R) of the side rib (30), and in addition, a region in which seal performance is degraded can be set with respect to the value per unit length of the rib reaction force (F) of the side rib (30) and the value of the rib surface roughness (R) of the side rib (30).

[0047] The setting of the torque disturbance area and the seal performance degradation area can be based on the value of the rib reaction force (F) per unit length of the side lip (30) (rib reaction force (F) / hub analog diameter (DE)) obtained by the evaluation test described above, and the value of the rib surface roughness (R) of the side lip (30). The setting of the torque disturbance area is achieved by plotting the evaluation test results on a graph as shown in FIG. 8 and setting an area that includes the entire plot of torque disturbance. The boundary line of the torque disturbance area can be set by connecting the plot of torque disturbance with a smooth line. Additionally, the boundary line of the torque disturbance area can be set by drawing a line in which the value of the rib surface roughness (R) of the side lip (30) increases as the value of the rib reaction force (F) per unit length of the side lip (30), which includes the plot of torque disturbance, increases. Since it is thought that stick-slip is more likely to occur as the rib reaction force (F) increases, the boundary line of the torque disturbance region is thought to be a line where the value of the rib surface roughness (R) of the side rib (30) increases as the value of the rib reaction force (F) per unit length of the side rib (30) increases. The boundary line of the torque disturbance region is, for example, a slanted straight line, and also, for example, a quadratic curve in which the slope of the tangent decreases as the value of the rib reaction force (F) per unit length increases. The boundary line of the torque disturbance region is not limited to a slanted straight line or the quadratic curve described above, but can be various lines based on the plot of the torque disturbance.

[0048] The setting of the seal performance degradation area is achieved by plotting the evaluation test results on a graph as shown in FIG. 8 and setting an area that includes the entire plot of seal performance degradation. The boundary line of the seal performance degradation area can be set by connecting the plot of seal performance degradation with a smooth line. Additionally, the boundary line of the seal performance degradation area can be set by drawing a line in which the value of the lip reaction force (F) per unit length of the side lip (30) increases as the value of the lip surface roughness (R) of the side lip (30), which includes the plot of seal performance degradation, increases. Since it is thought that as the lip reaction force (F) increases, it becomes difficult for wastewater to enter, and as the lip surface roughness (R) increases, it becomes easier for wastewater to enter, the boundary line of the seal performance degradation area is thought to be a line where the value of the lip reaction force (F) per unit length of the side lip (30) increases as the value of the lip surface roughness (R) of the side lip (30) increases. The boundary line of the seal performance degradation area is, for example, a slanted straight line, and a quadratic curve in which the slope of the tangent decreases as the value of the lip surface roughness (R) of the side lip (30) increases. The boundary line of the seal performance degradation area is not limited to a slanted straight line or the quadratic curve described above, and can be various lines based on the plot of seal performance degradation.

[0049] Also, as shown in FIG. 8, in prototype examples 1 to 25, there were no side ribs (30) with reduced seal performance. In such cases, a plot assumed to be closest to the area of ​​reduced seal performance among the evaluation test results can be selected for each rib surface roughness (R) or for each predetermined range of rib surface roughness (R), and the area of ​​reduced seal performance can be set based on this selected plot. For example, the area of ​​reduced seal performance can be set by connecting the selected plots with a smooth line as described above. Additionally, the area of ​​reduced seal performance can be set by moving each of the selected plots by a predetermined width in a direction closer to the area of ​​reduced seal performance as described above, and connecting them with a smooth line. Specifically, for example, such as the boundary line of the seal performance degradation area shown in Fig. 8, among the evaluation test results (plots), the plot with the smallest value per unit length of rib reaction force (F) in each group of plots where the rib surface roughness (R) is close can be selected, and the line passing through the side where the value per unit length of rib reaction force (F) becomes smaller by a predetermined width than these selected plots can be set as the boundary line of the seal performance degradation area.

[0050] As shown in FIG. 8, by setting a torque disturbance area and a seal performance degradation area, a design area can be set in which the value per unit length of the lip reaction force (F) of the side lip (30) and the lip surface roughness (R) of the side lip (30) are considered not to cause torque disturbance and not to cause seal performance degradation. The design area is an area in which the value per unit length of the lip reaction force (F) of the side lip (30) and the lip surface roughness (R) of the side lip (30) are not included in the torque disturbance area and the seal performance degradation area. Additionally, a specific area (target area) within the design area may be set as the value per unit length of the lip reaction force (F) of the side lip (30) and the lip surface roughness (R) of the side lip (30). A specific target area is, for example, an area within a design area separated by a predetermined width from each of the boundary lines of the torque disturbance area and the boundary line of the seal performance degradation area. Additionally, a specific target area is, for example, a range of values ​​per unit length of a specific rib reaction force (F) within the design area and a range of specific rib surface roughness (R) within the design area.

[0051] Specifically, for example, the side lip (30) that falls into the area (target area (I)) indicated by the dashed frame in FIG. 8 does not cause torque disturbance and does not degrade seal performance, and the target area (I) can be set as an area of ​​the side lip (30) where torque disturbance does not occur and seal performance does not degrade. For example, the target area (I) can be set as an area where the value of “lip reaction force (F) / hub analogue diameter (DE)” is 0.05 N / mm or more and 0.09 N / mm or less, and the value of lip surface roughness (R) is RzJIS 10㎛-α or more and RzJIS 10㎛+α or less. Also, α is, for example, a tolerance during the molding of the side lip (30) and is a value that takes into account the deviation of the lip surface roughness (R) that may occur during the manufacturing of the side lip (30).

[0052] Based on the results of the evaluation test described above, in the hub seal (1) related to the embodiment of the present invention, the value of the "rib reaction force (F) / hub diameter (D)" of the side lip (30), which is the value per unit length of the rib reaction force (F) of the side lip (30), and the rib surface roughness (R) are such that the side lip (30) falls within the design area. Specifically, for example, in the hub seal (1) related to the embodiment of the present invention, the value of the "rib reaction force (F) / hub diameter (D)" of the side lip (30) and the rib surface roughness (R) fall within the target area (I) shown in FIG. 8. In short, the value of the "rib reaction force (F) / hub diameter (D)" of the side lip (30) of the hub seal (1) is 0.05 N / mm or more and 0.09 N / mm or less. The lip reaction force (F) is adjusted based on at least one of the lip angle (A), lip thickness (DL), lip length (L), and the shape of the lip base (36) of the side lip (30), and the shape of the side lip (30) of the hub seal (1) is such that the value of “lip reaction force (F) / hub diameter (D)” is 0.05 N / mm or more and 0.09 N / mm or less. For example, by adjusting at least one of the values ​​of the lip angle (A), lip thickness (DL), lip length (L), and the shape of the lip base (36) of the side lip (30), the shape of the side lip (30) of the hub seal (1) is such that the value of “lip reaction force (F) / hub diameter (D)” is 0.05 N / mm or more and 0.09 N / mm or less. In addition, the value of the lip surface roughness (R) of the side lip (30) of the hub seal (1) is RzJIS 10㎛-α or greater and RzJIS 10㎛+α or less. α is a value that takes into account the deviation in lip surface roughness (R) that may occur during the manufacturing of the side lip (30) as described above, for example, α=3㎛.

[0053] As described above, the boundaries of the torque disturbance region and the seal performance degradation region can be various boundaries based on the results of evaluation tests, the design concept regarding the safety factor, and other factors such as the shape of the hub seal (1), and accordingly, the design region can also be various regions. In addition, the target region can also be various regions. For example, the torque disturbance region, seal performance degradation region, design region, and target region may be as shown in FIG. 9.

[0054] Regarding the adjustment of the rib reaction force (F) of the side rib (30), for example, the closer the rib angle (A) is to 90°, the higher the rib reaction force (F). Also, the larger the rib thickness (DL), the higher the rib reaction force (F). Additionally, if the rib length (L) is increased, the rib reaction force (F) increases. However, in relation to the rib thickness (DL) and the elastic modulus of the side rib (30), it is thought that if the rib length (L) exceeds a predetermined length, the reaction force decreases. Furthermore, if the shape of the rib base (36) is made such that the elastic modulus of the rib base (36) increases, the rigidity of the rib base (36) increases, and the rib reaction force (F) increases. In order to increase the elasticity of the rib base (36), for example, it is considered to increase the rib thickness (DLb) of the rib base (36).

[0055] <Method for manufacturing herb seal (1)>

[0056] [Illegible] This is the case with the 10 people who visited the site. It is the same as the 10 people who visited the site. It is the same as the 10 people who visited the site. The number of people who visited the site was determined by the 10 people who visited the site. The 10 people who visited the site was the same as the 10 people who visited the site. The 10 people who visited the site was the one who visited the site. The 10 people who visited the site and the 10 people who visited the site were the ones who visited the site. The 10 people who visited the site and the In a method for manufacturing a hub seal related to an embodiment of the present invention, a design area is set in advance by conducting the evaluation test described above, and in the process of forming an elastic body part (20) of a hub seal (1) as an elastic body, a value of “rib reaction force (F) / hub diameter (D)” and a lip surface roughness (R) that fall within the pre-set design area are selected, a side lip (30) having the selected value of “rib reaction force (F) / hub diameter (D)” and lip surface roughness (R) is designed, and the designed side lip (30) is manufactured. Accordingly, the side lip (30) has a shape that suppresses torque disturbance and the deterioration of seal performance. Furthermore, a hub seal (1) having a side lip (30) that suppresses torque disturbance and the deterioration of seal performance can be designed simply and quickly.

[0057] In addition, in the method of manufacturing the hub seal, the side lip (30) having the selected “lip reaction force (F) / hub diameter (D)” value and lip surface roughness (R) described above is designed by adjusting at least one of the lip reaction force (F) of the side lip (30), the lip angle (A), lip length (L), lip thickness (DL), lip surface roughness (R), and the shape of the lip base (36) of the side lip (30).

[0058] Specifically, for example, in the method of manufacturing a hub seal, the shape of the side lip (30) is designed such that the value of the "lip reaction force (F) / hub diameter (D)" of the side lip (30) and the lip surface roughness (R) fall within the target area (I) shown in FIG. 8. More specifically, for example, in the method of manufacturing a hub seal, the side lip (30) is designed such that the value of the "lip reaction force (F) / hub diameter (D)" of the side lip (30) is 0.05 N / mm or more and 0.09 N / mm or less, and also the lip surface roughness (R) of the side lip (30) is RzJIS 10㎛-α or more and RzJIS 10㎛+α or less.

[0059] Below, the method for manufacturing a herb seal (1) is described in detail. FIG. 10 shows a flowchart of the herb seal manufacturing process for manufacturing a herb seal (1).

[0060] As shown in FIG. 10, in the hub seal manufacturing process, first, a side lip design standard data having a design area, a torque disturbance area, and a seal performance degradation area is referenced based on the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) (Step S1). The side lip design standard data is data containing combinations of "rib reaction force (F) / hub diameter (D)" and rib surface roughness (R) belonging to the design area, combinations of "rib reaction force (F) / hub diameter (D)" and rib surface roughness (R) belonging to the torque disturbance area, and combinations of "rib reaction force (F) / hub diameter (D)" and rib surface roughness (R) belonging to the seal performance degradation area, and is visually represented as the data shown in FIG. 8 and 9.

[0061] Next, in Step S2, a combination of "rib reaction force (F) / hub diameter (D)" and "rib surface roughness (R)" belonging to the design area is selected from the side lip design standard data. Next, a hub seal (1) having a side lip (30) having the "rib reaction force (F) / hub diameter (D)" and "rib surface roughness (R)" selected in Step S2 is designed (Step S3). Next, the hub seal (1) designed in Step S3 is manufactured (Step S4).

[0062] Next, the process of creating side lip design standard data referenced in step S1 of the hub seal manufacturing process shown in FIG. 10 will be described. The process of creating side lip design standard data is performed in advance prior to the hub seal manufacturing process shown in FIG. 10. Once created by the process of creating side lip design standard data, the side lip design standard data can be used whenever the hub seal manufacturing process is performed. FIG. 11 shows a flowchart illustrating the process of creating side lip design standard data referenced in step S1 of the hub seal manufacturing process shown in FIG. 10.

[0063] In the process of creating standard data for side lip design, a plurality of hub seals (1) (sample hub seals) having side lips (30) with different combinations of “lip reaction force (F) / hub diameter (D)” and lip surface roughness (R) are prepared (step S11). Subsequently, for each of the sample hub seals prepared in step S11, an evaluation test is performed to confirm the occurrence of torque disturbance of the hub described above and the degradation of seal performance (step S12).

[0064] Next, from the results of the evaluation test in Step S12, the combination of "rib reaction force (F) / hub diameter (D)" and "rib surface roughness (R)" of each sample hub seal is classified and stored as a design area, a torque disturbance area, or a seal performance degradation area (Step S13). Accordingly, standard side lip design data is created. The classification in Step S13 is carried out by plotting the "rib reaction force (F) / hub diameter (D)" and "rib surface roughness (R)" of each sample hub seal on a graph of "rib reaction force (F) / hub diameter (D)" and "rib surface roughness (R)" as shown in FIGS. 8 and 9, and also connecting the evaluation results of each sample hub seal in Step S12 to the corresponding plot, and setting the boundaries of the torque disturbance area and the seal performance degradation area as described above, respectively, and setting the torque disturbance area, the seal performance degradation area, and the design area. Accordingly, the combination of "rib reaction force (F) / hub diameter (D)" and "rib surface roughness (R)" of each sample hub seal is classified into a design area, a torque disturbance area, or a seal performance degradation area. Furthermore, the method of classifying the combination of "rib reaction force (F) / hub diameter (D)" and "rib surface roughness (R)" of the sample hub seal into a design area, a torque disturbance area, or a seal performance degradation area is not limited to the visual method described above. For example, the method of classifying the combination of "rib reaction force (F) / hub diameter (D)" and "rib surface roughness (R)" of the sample hub seal into a design area, a torque disturbance area, or a seal performance degradation area may be a method based on calculation.

[0065] Additionally, FIG. 12 shows a flowchart illustrating a side lip element selection process for selecting a combination of "lip reaction force (F) / hub diameter (D)" and lip surface roughness (R) in step S2 of the method for manufacturing a hub seal shown in FIG. 10. In the side lip element selection process, first, the hub diameter (D) is set based on the specifications of the hub bearing to which the hub seal (1) is applied (step S21). Next, a combination of "lip reaction force (F) / hub diameter (D)" and lip surface roughness (R) belonging to the design area is selected from the side lip design standard data referenced in step S1 of the method for manufacturing a hub seal shown in FIG. 10 (step S22). Next, a side lip (30) having the "lip reaction force (F) / hub diameter (D)" and lip surface roughness (R) selected in step S22 is designed (step S23). Next, it is determined whether the side lip (30) designed in step S23 is structurally valid for the hub bearing to which the hub seal (1) is applied (step S24). In step S24, if it is determined that it is valid (Yes in step S24), in step S25, the combination of the "lip reaction force (F) / hub diameter (D)" and lip surface roughness (R) selected in step S22 is confirmed as the combination of the "lip reaction force (F) / hub diameter (D)" and lip surface roughness (R) selected. Meanwhile, if it is determined in Step S24 that it is not valid (No in Step S24), return to Step S22 and select a different combination of “rib reaction force (F) / hub diameter (D)” and rib surface roughness (R) belonging to the design area.

[0066] FIG. 13 is a diagram showing a flowchart of a conventional method for manufacturing a hub seal. In a conventional method for manufacturing a hub seal, a hub seal is designed based on the specifications of the hub bearing to which the hub seal is applied, the designed hub seal is prototyped, and an evaluation test is conducted on the prototyped hub seal to check for the occurrence of torque disturbance in the hub and degradation of seal performance. Then, if it is determined from this evaluation test that the designed hub seal does not meet the requirements, a new hub seal is designed, the newly designed hub seal is manufactured, and an evaluation test is conducted on it. The design and manufacture of this new hub seal and the execution of the evaluation test on the newly manufactured hub seal require a long period of time. On the other hand, according to the method for manufacturing a hub seal related to an embodiment of the present invention, once the side lip design standard data is created once, the side lip (30) can be designed without conducting an evaluation test, and the hub seal (1) can be manufactured in a shorter period of time.

[0067] According to the method for manufacturing a hub seal related to the embodiment of the present invention, even if processing marks remain on the inner surface (55d) or the transition part (55c) of the wheel mounting flange (55b) of the hub wheel (55) that the side lip (30) contacts in the state of use, the degradation of the seal performance can be suppressed, and the disturbance of the rotational torque of the hub bearing (50) or the occurrence of noise can be suppressed.

[0068] Although embodiments of the present invention have been described above, the present invention is not limited to the method of manufacturing a hub seal related to the embodiments of the present invention, but includes all aspects included in the concept and claims of the present invention. Furthermore, each component may be appropriately and selectively combined to exhibit at least some of the problems and effects described above. Explanation of the symbols

[0069] 1 : Hub seal 10 : Reinforcement ring 11 : Fit part 11a : outer surface 12: Position adjustment unit 12a : Return part 12b : Connection flange 12c : Return part 12d: Rib flange section 13: Flange section 20: Elastic body part 21 : Middle lip 21a : Siilmyeon 22 : Main Rib 22a : Siilmyeon 23 : Gas section 24 : Circumferential projection 24a : Outer end 25 : Embankment 26 : Gasket section 30: Side rib 31 : Siilmyeon 32 : Siil-myeon Seondan 33 : Siilmyeon Geunwondan 34 : Outsourcing 35: Rib tip 36 : Lip root 36a : outer surface 36b : If you give it to me 37 : Seal tip edge 50 : Hub bearing 51: Outer ring 51a: External opening 51b : Internal opening 51c : If you give it to me 51d: External section 52 : Hub 53 : Bearing ball 54 : Inner ring 55: Hub wheel 55a : Shaft 55b: Wheel mounting flange 55c : Transition part 55d : Inner surface 55e : Outer surface 56 : Maintenance 57 : Through hole 58 : Other hub seals E1: Reaction force measuring device E2 : Upper arm E3 : Lower arm E4 : Disc E5: Load cell E10: Test device E11 : Rotation axis E12: Herb analogue E13 : Face E14: Outer ring analogue E15 : Fixed part E16: Sealed head E17 : Leakage sensor E18: Torque meter A: Rib angle B1, B2: Boundary line D: Hub diameter DE: Hub analog diameter DL, DLb: Lip thickness e : Extension direction F: Rib reaction force G : Greece I: Target Area L: Rib length R: Lip surface roughness S: Space x : axis

Claims

Claim 1 A method for manufacturing a hub seal having a side lip and intended to seal the space between the outer ring of a hub bearing and the hub, wherein the rib reaction force (F), which is the value of the reaction force of the side lip in a state of use, is divided by the hub diameter (D), which is the value of the diameter of the hub (rib reaction force (F) / hub diameter (D)), and the rib surface roughness (R), which is the value of the surface roughness of the seal surface that contacts the hub of the side lip, are based on selecting the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) that are included within a design area, which is a preset area of ​​the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R), and wherein the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) are such that the selected rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) are formed. A method for manufacturing a hub seal, wherein the design area is a torque disturbance area which is a region of the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) that is preset based on the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R), and a seal performance degradation area which is a region of the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R) that is preset based on the rib reaction force (F) / hub diameter (D) and the rib surface roughness (R), wherein the torque disturbance area is a region where torque disturbance is expected to occur, and the seal performance degradation area is a region where seal performance is expected to degrade. Claim 2 A method for manufacturing a hub seal according to claim 1, wherein the rib reaction force (F) is determined based on at least one of the angle of the extension direction of the side rib with respect to the direction perpendicular to the axis of the hub seal, the length of the extension direction of the side rib, the thickness in the direction perpendicular to the extension direction of the side rib, and the shape of the origin of the side rib. Claim 3 A method for manufacturing a hub seal according to claim 1, wherein the lip reaction force (F) / hub diameter (D) and the lip surface roughness (R) are selected within a target area, which is a preset area within the design area. Claim 4 A method for manufacturing a hub seal according to claim 3, wherein the range of the lip reaction force (F) / hub diameter (D) in the target area is a range of 0.05 N / mm or more and 0.09 N / mm or less, and the range of the lip surface roughness (R) in the target area is within a range of RzJIS 10㎛-α or more and RzJIS 10㎛+α or less, and α is a tolerance during the molding of the side lip. Claim 5 A method for manufacturing a hub seal, wherein, in any one of claims 1 to 4, the side lip having the selected lip reaction force (F) / hub diameter (D) and the lip surface roughness (R) is determined to be formed in the hub bearing, and the lip reaction force (F) / hub diameter (D) and the lip surface roughness (R) are selected.

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