JP2560100B2 - Seal assembly - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION 3-1 Object of the Invention The present invention relates to a seal assembly. Especially for use with a bearing mounted between two relatively removable or relatively rotatable members between a fixed housing and a rotatable and axially removable shaft, or alone. It concerns the seals used.

Diaphragm type seals have hitherto been used in rotary seals such as between a rotary shaft and a spindle housing in a motor. Generally, the most effective sealing method is to maintain a constant pressure over the entire circumference of the contact surface of the seal ring, regardless of the axial deviation or eccentricity that occurs when the shaft shakes. Therefore, it is desirable to configure the seal ring to form a thin annular band on the sealing surface that contacts the surface to be sealed. The thin contact zone provides optimum sealing conditions, and can prevent contamination and excessive wear of the sealing surface that would occur when an axial acting force acts on a specific portion of the sealing surface. This thin contact zone is also found to have excellent sealing ability despite imperfect seal surfaces and high speed rotation of the seal ring and shafts that generate centrifugal forces acting outward of the seal surface. ing. Further, the seal lip is in sealing engagement with the surface to be sealed, regardless of changes in force or atmospheric pressure acting on the sealing surface or changes in pressure caused by shaft movement or sudden temperature changes, It is important that it is not disengaged by any force tending to separate the sealing lip from the surface to be sealed.

It is an object of the invention, first of all, to improve the seal, which is a face seal used between the spindle housing and the axle for motor vehicles. The seal according to the invention can also be used in other applications and environments.

Another object of the present invention is to provide a new and improved axle grease or oil seal, and in particular to prevent impurities from entering the housing through the seal and lubricating oil in the seal. By holding the bearing, damage to the bearing can be prevented, wear of the seal can be reduced and life can be extended, and the bearing can be installed between the axle and the housing to distribute the acting force over a large area and reduce heat generation and wear. It is in.

Another object of the invention is to provide an axle with the characteristics of a diaphragm having a flexible annular wall which is self-compensating for wear, offset and end play and which eliminates the need for a separate spring member. It is to provide a seal assembly that can be used between spindle housings.

Another object of the present invention is to provide a seal assembly that can be used between an axle and a spindle housing to minimize heat generation and wear at high speed and to have optimum sealing performance and load characteristics.

3-2 Configuration of the Invention Embodiments of the rotary face seal according to the present invention may be provided between an external member, such as a fixed spindle housing, and an internal member, such as an axle. The axle is rotatable with respect to the spindle housing and is axially removable, and the spindle housing also has a radially extending wall (radial wall). The seal assembly includes an annular diaphragm made of an elastomeric material, the annular diaphragm contacting an inner seat provided around the axle and a radial wall of the housing which is tapered axially from the outer periphery of the diaphragm, A sealing lip adapted to form a sealing surface, the diaphragm further having an annular (toroidal) intermediate wall, whereby the sealing lip is provided in a thin annular contact zone with the radial wall of the housing. The soft contact allows the seal lip to self-correct for wear and prevents impurities from entering the space between the spindle housing and the axle.

In an embodiment, the axle is rotatable about a linear axis, but the spindle housing is relatively fixed. On the contrary, it is also possible to fix the axle and rotate the spindle housing. Desirably, the seal is provided on the axle so as to be concentric with the axle and its axis, and the thin annular surface portion formed by the seal lip and the radial wall of the spindle housing may be concentric with the axle and its axis. desirable. Further, if desired, the spindle housing can include a portion concentric with the axle. Also, the radial wall with which the seal lip contacts to form a thin annular surface can be considered as a radial surface or a facing surface.

Briefly, a seal of an embodiment according to the invention relating to a plurality of members which are relatively movable, for example relatively rotatable or axially displaceable, The member has a body or contact portion, a seal portion, and an intermediate portion. The body portion has a seal portion at a position corresponding to one of the plurality of members, for example, a member such as an axle. For the purposes of the following description, it takes the form of a seal ring inside the first body portion, as illustrated in the preferred embodiment of the present invention, the sealing portion comprising an axial surface or a spindle housing. It takes the form of a sealing lip that engages the opposite surface. The main body portion can also be referred to as a seal ring or an internal seal ring depending on the relative positional relationship in the embodiment of the present invention.
The sealing portion provides a sealing function to a secondary portion such as a radial surface portion or a facing portion of the spindle housing. For the following description, this seal portion is called a seal lip. The middle part, which is often called the annular wall of the diaphragm part, connects the body part and the seal part,
In a sense, the seal is provided with a sealing force capable of absorbing relative axial and radial movements of the main body and the secondary portion.

Under the influence of the annular wall and the outer seal, the sealing lip forms a thin annular surface, for example with the radial wall of the spindle housing. Compared to the contact line, such a thin annular surface can distribute the acting force over a relatively large surface area, which allows a faster rotation of the seal, which is also used The device suppresses the rise in frictional heat, which in other seals leads to increased friction and wear.

The seal portion has one or more relatively rigid portions to reinforce each portion of the seal portion or to maintain radial and axial stability of the seal. These parts can be independent of the other parts of the seal, can also be one or more parts thereof and can be composed of metal, plastic or relatively rigid materials. Further, in one embodiment, one of these relatively rigid portions is joined to or housed within an inner seal ring to facilitate attachment of the seal to, for example, an axle, and in yet another embodiment, , The second relatively rigid part is joined to the outer seal part or is housed inside to act as a directional fulcrum or lever fulcrum, and the force generated by the rotational movement of the annular wall part is applied to the seal lip. It is designed to work towards each other, which allows a seal against the radial surface of the spindle housing.

The thrust bearing can be provided on the inner surface of the radial wall portion and the inner diameter portion of the spindle housing having the seal portion around the axle, and the thrust bearing can freely rotate with respect to the spindle housing and the seal portion.

Other objects, advantages and features of the present invention will be easily understood by the following description and the accompanying drawings.

3-3 Embodiment In the embodiment shown in FIGS. 1 and 2, the seal assembly (8) is relatively movable and is provided between members (14) (16) disposed inside and outside. A seal (10) and a thrust bearing (12). The seal assembly (8) is mounted between an outer fixed spindle housing (14) and the inner shaft (16) of the vehicle. At its outer end, the shaft (16) comprises a radial surface portion (17), an axially extending shoulder portion (18) and an enlarged end portion (20). Conventionally, the spindle housing (14) is also called an inner diameter portion (22) and a radial surface portion or a facing portion which are provided so as to face the shaft (16) with a space therebetween.
The radial surface (2) facing the radial surface (17) of (6)
4) and a circular flange (26) extending outward from the outer end of the spindle housing (14).

Desirably, the shaft (16) has a linear axis of rotation, and the inner diameter (22) of the spindle housing is positioned relative to the shaft such that the inner diameter and the shaft are concentric or essentially concentric. In a sense, spindle housing (14)
Can also be at least partially concentric with the axis. Precise concentricity is not necessarily a limitation for proper use and operation of the present invention, and in practice concentricity is not usually required for use and operation of the present invention.

In the above setting, the seal (10) is provided between the spindle housing (14) and the shaft (16) to prevent dust, water or other impurities from entering the space between the spindle housing (14) and the shaft (16). In addition, the lubricating oil such as grease is prevented from leaking from this space. Free end play, misalignment, and slight axial deflection, whether the shaft rotates or does not rotate with respect to the spindle housing (14), to obtain an effective seal. In contrast, the seal can be corrected. Further, the face seal overcomes the pressure reducing effect to maintain a sealed engagement with the axial surface or the opposite surface (24) in the following manner.

The overall structure and configuration of the seal (10) is shown in Figs.
As best seen in the drawings, the seal (10) is made of an elastomer or rubber or rubber-like material and has a diaphragm (30) with an internal seat (32).
And an inner seat portion (32) consisting of a ring-shaped surface portion (33) and an outer concentric seal portion (34).
6), the ring (36) is relatively stiffer than the diaphragm, and the inner seat (32) is stiffer when mounted on the shaft (16) as shown in FIGS. 1 and 2. A compression is provided between the ring (36) and the shaft (16). The outer backing ring (38) is also a rigid member, which is located outside concentrically to the inner seat (32) and is permanently joined to the seal (34) to create a seal. Of the annular surface portion (33) and the force generated by the rotational movement of the annular surface portion (33) facing the spindle housing (14) shown in FIGS. 1 and 2 via the sealing portion (34). It acts as a fulcrum that acts on the tapered seal lip (40) at the end of (34). In other words, the annular surface portion (33) is
The axial loading of the sealing lip (40) on the spindle housing (14) without the use of a separate spring when axial operation occurs between the shaft (16) and the spindle housing (14). You can

The required elasticity lies in the flexible annular surface (33) of the diaphragm, so that the sealing lip (40) always remains in the spindle housing (14) regardless of the axial movement between the shaft (16) and the spindle housing (14). It acts like a cantilever to keep the contact flexible with the radial surface (24) of the. FIG. 5 shows the free or relaxed state of the annular surface portion (33). When the annular surface portion (33) becomes the state shown in FIG. 3, it returns to the state shown in FIG. It is formed in a shape that accumulates such reaction force. Pressure builds up axially on the seal lip (40) due to the combination of reaction forces and rotary motion of the diaphragm accumulated in the annular surface (33) and the restriction or restraint created by the outer backing ring (38).

Referring to the structure and configuration of the member comprising the seal (10) in more detail, and referring to FIGS. 3 to 5, the inner seat portion (32) is generally U of the diaphragm (30).
One side or leg of the character-shaped inner end (42) is limited, and the leg on the opposite side limits the outer end continuous portion of the annular surface (33) extending in the axial direction, and further the inner end (42). It is desirable that the closing part (43) of (1) joins the inner seat part (32) and the inner leg part (44). The rigid ring (36) has an overall L-shaped cross section, and an axially extending flange (46) inserted into the open end of the U-shaped cross section and inward from one end of this flange (46) and It is preferably constructed of a rigid metal material including a radially extending flange (47). The ring (36) is mechanically held at a predetermined position, and a series of through holes (48) are provided in the flange (46). Further, the elastomer material of the diaphragm forms the through holes (48) at the time of forming the diaphragm. It is desirable to be integrated with the inner seat portion (32) so as to pass therethrough. The mechanical connection by the method described above eliminates the need for a scientific connection and allows the inner seat (32) and the inner leg (44) to be integrated during the molding process.

The structure of the inner seat (32) and the ring (36) according to the method described above greatly facilitates the attachment of the diaphragm to the shaft having the inwardly extending flange (47) in contact with the radial surface (17) of the shaft. . No special surface is required on the mating surface of the shaft or ring, and no special equipment is required to attach the seal to the shaft (16). The seal (10) need only be pushed on the shaft (16) until the ring (36) and flange (47) join the shoulder (18) and the radial surface (17). When the seal (10) contacts the shaft (16) sufficiently, the inner seat (32) is compressed between the ring (36) and the shaft (16).

The annular surface portion (33) bends according to the relative movement between the spindle housing (14) and the shaft (16), and therefore receives the rotational movement. In particular, the annular surface portion (33) has an annular shape or an uneven shape as a whole, and the convex surface portion faces the spindle housing (14). Further, the annular surface portion extends from the inner leg (44) to form a generally circular or arcuate shape and has a constant thickness up to the axially extending outer leg (52). The outer leg portion (52) of the annular surface portion (33) is integrally connected to the end portion of the seal portion (34), and is attached to the inner surface (56) of the seal according to the axial movement of the shaft (16). You can move freely along. Furthermore, in order to provide the necessary deflection action to the seal lip (40), the diaphragm (30) is shaped so that the inner surface shown in FIG. 5 is in the extended position in the relaxed state. Therefore, when the inner seat portion (32) is axially moved from the position shown in FIG. 5 to the position shown in FIG. 4 toward the radial wall body, the other end of the annular surface portion (33) or Since the leg (52) moves to the vicinity of the seal body (34) and increases the deflection of the annular surface portion (33), the annular surface portion (3
3) and the other end (52) continuously displace the sealing lip (40) towards the radial wall. As the inner seat (32) continues to move, the inner seat (32) continues to move toward the position shown in Figure 3, assisted by the displacement action of the inner leg or end (44). As such, this displacement action or force is maintained.

The seal (34) has a solid shape, generally a rectangular solid block, and has a greater radial thickness than the rest, making it relatively flexible to the seal lip (40). It is desirable to reduce the sex. The outer backing ring (38) has a generally L-shaped cross section, and is further formed in an axially extending flange (61) formed in the outer peripheral surface (62) of the block and an outer end surface extending in the radial direction of the block. Is molded in the seal portion (34) by the flange (63). The outer backing ring (38) is a member having a sufficient angle to maintain the elasticity or the uniformity of the diameter of the seal portion and to apply the force generated by the movement of the annular surface portion (33) on the surface of the seal lip (40). It acts as a support member having a directivity to act on. The seal portion (34) converges on the hinge portion (66) at a portion facing the outer backing ring (38) and is further connected to a taper portion (68) terminating at the seal lip (40). This hinge part (66)
Intersects along the common circumferential intersection line (73) 2
It is desirable to be limited by two inclined surfaces (70) (72). The hinge action is the intersection line (7) of the inclined surfaces (70) (72).
As occurs in 3), this is done by reducing the cross-sectional thickness on the back side of the hinge, but preferably with a slight offset from the intersection line (73) to form a peripheral groove or radius (74). The outer peripheral surface (76) is inclined radially and outwardly, intersects the surface portion (77) extending radially and outwardly, and is further converged by the seal lip (40) as shown in the drawing. Depending on the positional relationship between the intersection line (73) and the groove (74), the seal lip (4
It allows the sealing lip (40) to deform radially and outwardly with respect to the line of intersection (73) when the 0) is pressed against the sealing surface defined by the radial surface section (24) of the spindle housing. This outward deformation also acts as a second means of exerting an axial load on the sealing lip (40) in a manner similar to that when the ridges direct the force linearly or axially. The face (77) adjacent to the seal lip (40) is angled at an acute angle in the radial direction, thereby defining a thin contact band when the seal lip (40) is outwardly deformed as described above. At the same time, the sealing force is spread over a large area on the radial surface portion (24) of the spindle housing (14). In this way, by applying the force over a wide range, the seal lip (40) can rotate at high speed while minimizing heat generation and wear on the surface portion (77), and the axial deflection action of the diaphragm further allows the seal lip (40) to rotate. The seal contact performance with the radial surface portion (24) is improved on the entire circumferential surface of (40). Seal lip (40) when the inner seat (32) moves axially towards the radial surface
The deflection force or pressure acting on the can be absorbed by the outward deformation of the sealing lip about the line of intersection (73).

As shown in detail in FIGS. 8 and 9, the desirable shape of the thrust bearing (12) is an annular shape as a whole, and the thrust bearing (12) is provided in the inner diameter portion of the spindle housing (14) and is attached to the shaft (16). On the other hand, it works as a seal part and as a journal for the spindle housing (14). The thrust bearing (12) consists of a seal retaining ring,
It has an end flange (81) facing radially inward and an end flange (82) on the opposite side. The annular seal (83) has a seal lip (84) at the radially inner end and an endless coil spring that acts at the outer periphery of the seal to compress the seal radially inward with respect to the surface of the shaft (16). The support portion (86) is made of a highly rigid and robust plastic material such as an internally lubricated nylon synthetic material having a low dynamic friction coefficient. The support part (86) has a cross-sectional shape that complements the shape of the flange (47) in the radial direction (17), whereby the end of the shaft (16) moves toward the support part (86). At this time, the two support parts (87) and (88) are supported, and the support part (86) is supported by the spindle housing (14)
It is pressed against the radial surface part (24) of the shaft so that the shaft (16) and the spindle housing (14) do not come into direct frictional contact. For this reason, the support portion (86) includes a surface portion (87) extending in the radial direction, a shoulder portion (88) having a step portion (89) between the surface portion (87), and the shaft (16) having a thrust bearing. An outer surface portion having an inner radial end (90) chamfered to serve as a guide for centering the shaft (16) when provided in the (12). Center the shaft (16) in place,
The guide protects the seal (83) from damage and prevents the spring (85) from shifting from the seal (83). The inner surface portion (94) of the support portion (86) is
A circular groove (93) with a small protrusion (93) is provided for a tight insertion of the outwardly extending flange (82) of the ring (80), so that the support (86) causes the ring (8) to move.
0) can be engaged, and can be freely moved with respect to the rest of the bearing portion. At the same time as the bearing, the support (86) can rotate freely with respect to the seal of the bearing fixed to the spindle housing, so that the friction force generated by the end of the shaft causes the surface (87) (88). And directly acts on the inner surface portion (94). Since it can freely rotate with respect to the spindle housing, the support portion (86) rotates with the shaft, but rotates at a speed lower than the rotation speed of the shaft.

As described above, the thrust bearing (12) is press-fitted into the inner diameter portion (22) of the spindle housing, but it is preferable to use a flat metal bar pressed against the outer surface portion of the support portion (86) to hold the thrust bearing (12). Force is evenly applied to tightly engage the ring (80) with the inner surface of the inner diameter. By this method, the thrust bearing (12) can be mounted without directly engaging with the seal (83). Further, as described above, the support portion (86) effectively surrounds and protects the spring (85) supporting the seal (83), and also prevents the displacement that occurs during mounting on the inner diameter portion. ing.

In the embodiment shown in FIGS. 10-12, the members are numbered similar to the seals shown in FIGS. 1-9. Therefore, another form of seal assembly (8 ') is that the seal (100) and the members (14') and (1
6 ') and a thrust bearing (12'), which is also an external fixed spindle housing, and the member (16 ') is a radial surface (1').
7 '), shoulder (18') and enlarged end (20 ') internal drive shaft. The spindle housing (14 ') has an inner diameter portion (22'), a radial surface portion (24 ') and a circular flange (26').

The seal (100) also comprises an elastomeric diaphragm (102) having an inner seat (32 '), a generally annular surface (33') and a seal (104). The inner seat portion (32 ') is fixed to the ring (36') in the same manner as the seal (10) shown in FIGS. 1 and 2, and the annular surface portion (33 ') further includes the spindle housing (14'). ) And the axis (16 ') move axially,
The seal (10) ensures that the seal (104) always flexibly engages the radial surface of the spindle housing (14 ').
It is constructed and arranged in the same manner as the annular surface portion (33).

An important feature of the invention shown in FIGS. 10-12 is the structure of the seal (104) which has an essentially uniform cross-sectional thickness, except that the connecting end (110) of the seal (104) is )
Excluding the tapered face (106) terminating at the seal lip (108) at the free end opposite. As shown, the face portion (106) is gradually inclined from the inner circumferential surface of the seal at a small angle until it intersects the outer circumferential surface.
The connecting end portion (110) is integrally formed with the outer end of the annular surface portion (33 ') or the outer leg portion (52'), and further, the connecting end portion (11).
The thickness in (0) is thicker than the thickness of the outer leg portion (52 '), and is thicker than the thickness of the annular surface portion (33'), which makes it more flexible than the annular surface portion (33 '). It is decreasing. The above-described seal can generate a force generated by the movement to the annular surface portion (33 ') without using a member such as a backing ring (38) shown in FIGS. 1 to 7 and a seal lip (108). It acts as a fulcrum that points to the face part of.

In its relaxed state, the diaphragm (102), in its relaxed state, provides a first deflection to provide the necessary deflection effect on the seal lip (108).
As shown in Fig. 1, the inner surface is in the extended position, and the seal (104) has a surface (10) opposite to the connecting end (110).
Mold in a state slightly deviated from the direction outward in the radial direction to 6). As shown in FIG. 12, due to the axial movement of the inner seat portion (32 ′) to the radial surface portion (24 ′), the annular surface portion (33 ′) becomes the inner peripheral surface (112) of the seal (104). Is bent outwardly away from the radial surface (24 '). On the contrary, the inner seat (32 ') moves axially away from the radial surface (24') to the position shown in FIG. 11, so that the annular surface (33 ') and the outer leg (52'). Keeps pushing the sealing lip (108) flexibly against the radial surface (24 ').

In applications that require high speed rotation of relatively moving members, as described with respect to FIGS. 1-7, in the absence of a solid backing ring, such as the outer backing ring (38), Radial face (2
The required load on the seal lip is maintained to maintain uniform contact with the 4 '), while at the same time reducing frictional wear and heat rise. Furthermore, the seals also resist axial disengagement and misalignment and end play between the members (14 ') (16').
While freely following the movement of the annular surface portion (33 '), the seal lip is kept in contact with the radial surface portion (24') at the thin annular surface portion.

The design and construction of the seals (10) and (100) does not require any special equipment to attach either seal to the shaft (16) or (16 '), and special modifications to the surface of the shaft and spindle housing. Is characterized in that there is no need to add. Furthermore, the inner seat (32) or (32 ') pressed against the surface of the shaft (16) or (16') is in firm contact with the ring (36) or (36 ') as described above. Seal up to (10) or (100) shaft (16)
Or just press on (16 '). In this regard, the inner seat (32) or (32 ') and the ring (36)
Obviously, or (36 ') can be varied depending on the particular shape of the shaft and the enlargement of the shaft. Similarly, the dimensions of diaphragm (30) or (102) can be varied appropriately to accommodate various mounting conditions and dimensional changes between the members to be sealed. Also, the materials described for similarly shaped seal and bearing assemblies are used for purposes of illustration and not limitation. However, what is important is that the diaphragm (30) or (102) configuration works well at pressure and velocity limitations and uses low compression forces.

While the preferred embodiments for seals and thrust bearings have been described above, various modifications and changes can be made in structure and arrangement, as well as material composition, without departing from the spirit and scope of the invention as claimed. It will be appreciated that you can.

[Brief description of drawings]

The drawings show an embodiment of the present invention, in which Fig. 1 is a sectional view of an embodiment of a seal assembly according to the present invention provided between a vehicle axle and a spindle housing, and Fig. 2 is a sectional view similar to Fig. 1. 4 shows relative movement between members when the axle moves axially with respect to the spindle housing. Figures 3, 4 and 5 are cross-sectional views of the seal,
FIG. 3 shows the rotational movement of the diaphragm corresponding to the relative axial movement between the axle and the housing shown in FIGS. 6 is a perspective view of an embodiment of the seal according to the present invention, FIG. 7 is a cross-sectional view taken along line 7-7 in FIG. 6, FIG. 8 is a plan view of an embodiment of the thrust bearing, and FIG. Fig. 8 is a sectional view taken along line 9-9 in Fig. 8, Fig. 10 is a sectional view of another embodiment relating to the seal, and Fig. 11 is a sectional view of the seal shown in Fig. 10 provided between the spindle housing of the motor and the axle. Sectional view of the embodiment, FIG. 12 is a sectional view of the embodiment shown in FIGS. 10 and 11.
5 shows the relative movement between the members as the shaft moves axially with respect to the spindle housing.

Claims (1)

(57) [Claims] 1. A seal provided with a radially extending outer peripheral surface on an outer member to be sealed with respect to the inner member, the seal being adapted to be mounted between spaced, relatively movable inner and outer members. An assembly, wherein the seal assembly is disposed around the inner member and has an annular diaphragm having a seat portion for engaging a seal with the inner member,
A circumferentially extending seal body having a free end in the form of a seal lip that axially tapers from the seal body and sealingly engages the radially extending circumferential surface.
For elastically urging the sealing lip axially with respect to a radially extending circumferential surface of the outer member regardless of relative movement between the inner and outer relatively movable members. A seal assembly comprising: an annular wall portion extending between the seat portion and the seal lip or an elastic means by an elastically deformable material.