JP6757186B2 - Axle sealing device and sealing member for agricultural machinery - Google Patents

Description

The present invention relates to a sealing device and a sealing member used for an axle of an agricultural machinery.

Agricultural equipment such as a tractor is equipped with a sealing device in the annular space between the axle and the shaft hole of the housing (final case) into which the axle is inserted. By installing the sealing device, the leakage of the lubricating oil in the housing is prevented, and foreign matter such as muddy water is prevented from entering the housing from the outside side of the housing.

As such a sealing device, for example, in Patent Document 1, a sleeve having a substantially L-shaped cross section fitted and fixed to the outer peripheral surface of the axle and a sleeve fitted and fixed to the inner peripheral surface of the housing are slidably contacted with the sleeve, respectively. A sealing device including a sealing member including a main lip (oil seal lip), an auxiliary lip (first and second dust seal lips), and a side lip (third dust seal lip) has been proposed (Patent Document 1, FIG. 1). reference).

Japanese Unexamined Patent Publication No. 2005-273864

In the conventional sealing device as shown in Patent Document 1, the side lip may be worn in a short period of time, and as a result, the sealing property may be impaired at an early stage. This is because the conventional sealing device has a small side lip tightening allowance, so that the sealing property is deteriorated even if it is slightly worn.
Therefore, it is conceivable to increase the tightening allowance of the side lip so that the sealing property is maintained even if the side lip is worn to some extent. However, when the tightening allowance of the side lip is increased, the tip of the side lip does not contact the sleeve, but contacts the sleeve in the middle of the base end side from the tip end, that is, the side lip contacts the sleeve in a so-called abdominal contact state. Will be. As a result, muddy water or the like easily enters the gap between the side lip and the sleeve, and if the side lip slides in contact with the sleeve while the muddy water or the like has entered, the wear of the side lip may be promoted. Therefore, it is difficult to maintain the sealing property for a long period of time only by increasing the tightening allowance of the side lip.

An object of the present invention is to provide a sealing device capable of maintaining the sealing property for a long period of time without the side lip being less likely to wear even if the tightening allowance is increased.

The axle sealing device for agricultural machinery of the present invention (hereinafter, also simply referred to as a sealing device) is between the inner peripheral surface of one end of an axle hole provided in the housing and the outer peripheral surface of the axle. Used to seal the annular space of
A seal member fixed to the inner peripheral surface of one end of the shaft hole,
A sleeve having a cylindrical portion fitted to the outer peripheral surface of the axle and an annular plate portion having an annular shape in contact with a flange portion provided on the axle is provided.
The sealing member is an axle sealing device for agricultural machinery having an annular main lip in contact with the cylindrical portion and an annular side lip in contact with the annular plate portion.
The side lip has a conical ring-shaped conical tube portion having an enlarged diameter on the annular plate portion side and a lip portion in contact with the annular plate portion, and is radially curved from the conical tube portion. Including an annular portion extending outward
The lip portion includes at least the outer peripheral edge of the surface of the annular portion on the side facing the annular plate portion.
Of the surface of the annular portion facing the annular plate portion, the portion radially inner of the lip portion is characterized in that a gap is provided between the annular portion and the annular plate portion.

According to the sealing device, the lip portion in contact with the annular plate portion of the sleeve includes the outer peripheral edge of the annular portion constituting the side lip and facing the annular plate portion, that is, the outer peripheral edge. Is in constant contact with the annular plate portion of the sleeve, so that muddy water or the like is unlikely to enter between the side lip and the sleeve even if the tightening allowance of the side lip is large, and therefore wear of the side lip is not easily promoted.
Further, even if the tightening allowance of the side lip is reduced due to the wear of the side lip over time, since the side lip includes the conical tube portion and the annular portion, the annular portion with respect to the conical tubular portion. The change in the tightening allowance can be absorbed by changing the angle of. As a result, the contact surface pressure on the sleeve of the outer peripheral edge can be maintained for a long period of time.
Therefore, the sealing device can maintain the sealing property for a long period of time in an environment exposed to muddy water or the like, and can be suitably used as an axle sealing device for agricultural machinery.

In the sealing device, the tightening allowance of the side lip with respect to the sleeve is preferably 2 to 5 mm.
The sealing device can maintain the sealing property for a long period of time even when it has such a large tightening allowance.

The sealing member of the present invention is a sealing member constituting the sealing device of the present invention.
With main lip and side lip,
In the free state, the side lip has an annular base end portion, a conical ring-shaped intermediate portion extending from the base end portion toward the annular plate portion side and an enlarged diameter on the annular plate portion side, and the annular portion from the intermediate portion. It has a conical ring-shaped tip portion that extends toward the plate portion and has a different inclination angle with respect to the axis of the axle from the intermediate portion.
A part of the intermediate portion and the tip portion form the annular portion of the side lip in the sealing member constituting the sealing device.
A sealing member having a side lip having such a configuration in a free state is particularly suitable as a sealing member constituting the sealing device of the present invention.

According to the present invention, it is possible to provide an axle sealing device for agricultural machinery that can maintain the sealing property for a long period of time, and a sealing member constituting the sealing device.

It is sectional drawing which shows the state which the sealing device of 1st Embodiment is attached. (A) is an enlarged cross-sectional explanatory view of the sealing device shown in FIG. 1, and (b) is an enlarged view of a main part of (a). It is sectional drawing which shows the free state of the seal member which comprises the sealing device shown in FIG. (A) is a cross-sectional explanatory view showing a free state of a sealing member constituting another sealing device, and (b) is a cross-sectional explanatory view showing a sealing device provided with the sealing member shown in (a). .. It is sectional drawing which shows the sealing device used in the performance evaluation.

(First Embodiment)
Hereinafter, embodiments of the sealing device and the sealing member of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional explanatory view showing a state in which the sealing device of the present embodiment is attached. FIG. 2A is an enlarged cross-sectional explanatory view of the sealing device shown in FIG. 1, and FIG. 2B is an enlarged view of a main part of FIG. 1A. FIG. 3 is a cross-sectional explanatory view showing a free state of the sealing member constituting the sealing device shown in FIG. FIG. 4A is a cross-sectional explanatory view showing a free state of a sealing member constituting another sealing device, and FIG. 4B is a cross-sectional explanatory view showing a sealing device provided with the sealing member shown in FIG. 4A. Is.
In the present specification, the wheel side is referred to as the axial outer side or the axial outer side in the direction along the axle of the agricultural machinery, and the opposite side along the axle direction is referred to as the axial inner side or the axial inner side.

In the sealing device 10 according to the present embodiment, as shown in FIG. 1, in the suspension of the front wheels of the tractor, the flange portion 11a for attaching the front wheels (not shown) is axially outside (left side in FIG. 1). A final case (housing) in which an axle 11 integrally provided at an end and a bevel gear 14 for rotatably supporting the axle 11 via a bearing 13 and transmitting a driving force to the axle 11 are housed. It is a sealing device used between 12 and 12.

The sealing device 10 is mounted in an annular space formed between the axle 11 and the shaft hole 12a into which the axle 11 provided in the final case (housing) 12 is inserted, and is installed in the internal space A of the final case 12. It prevents the sealed fluid such as the sealed lubricating oil from leaking to the outer side B of the final case 12, and also prevents muddy water or the like from entering the internal space A from the outer side B.
As shown in FIGS. 2A and 3A, the sealing device 10 includes a sealing member 15 and a sleeve 16. Note that FIG. 3 shows a seal member in a free state before deformation.

As shown in FIG. 2A, the sleeve 16 is composed of a metal ring 51 in contact with each lip of the sealing member 15 and an annular elastic portion 52 provided on the inner peripheral side and the axial outer side of the metal ring 51. Become.
The metal ring 51 has a cylindrical portion (first cylindrical portion) 51a fixed to the outer peripheral surface of the axle 11 via an elastic portion 52 and an axially outer side of the first cylindrical portion 51a (left side in FIG. 2A). A skirt-shaped connecting portion 51b extending axially outward and radially outward from the end of the connecting portion 51b, and an annular annular plate portion 51c extending radially outward from the axially outer end of the connecting portion 51b. It is composed of.

The elastic portion 52 is an annular member made of an elastic material such as synthetic rubber (for example, acrylonitrile-butadiene rubber (NBR), acrylic rubber (ACM), etc.). The elastic portion 52 is fixed to the metal ring 51 by, for example, bonding or baking by vulcanization.
The elastic portion 52 is provided on the entire axle 11 (including the flange portion 11a) side of the metal ring 51, but the elastic portion 52 is provided only on the inner peripheral surface side of the first cylindrical portion 51a, for example. May be good.

In the sleeve 16, the first cylindrical portion 51a is fitted to the outer peripheral surface of the axle 11 via the elastic portion 52, and the annular plate portion 51c comes into contact with the axially inner side surface of the flange portion 11a via the elastic portion 52. Is fixed to the axle 11.
In this way, by attaching the sleeve 16 so that the metal ring 51 comes into contact with the axle 11 via the elastic portion 52, the sleeve 16 passes between the axle 11 (including the flange portion 11a) and the sleeve 16 and enters the sealed space A. It is possible to prevent muddy water and the like from entering.

The seal member 15 is composed of an annular core metal 21 having a substantially crank-shaped cross section, a sealing portion 22 fixed to the core metal 21, and an annular spring ring 23.
The core metal 21 is an annular member made of metal (for example, SPCC or the like), and has a cylindrical tubular portion 21a and an annular shape that is bent outward in the radial direction from the axially outer end of the cylindrical tubular portion 21a. It is composed of a first core metal ring portion 21b and an annular second core metal ring portion 21c bent inward in the radial direction from the axially inner end of the cylindrical tubular portion 21a.

The sealing portion 22 is made of an elastic material such as synthetic rubber (for example, acrylonitrile-butadiene rubber (NBR), acrylic rubber (ACM), etc.) and is fixed to the core metal 21 by adhesion by vulcanization, baking, or the like.
The sealing portion 22 is formed in an annular shape, and has a main body portion 31 provided on the inner peripheral side of the core metal 21, a main lip 32 extending from the main body portion 31 to the sleeve 16 side, a first auxiliary lip 33, and a first. 2 It has an auxiliary lip 34 and a side lip 35, and an outer peripheral portion 36 provided on the outer peripheral side of the core metal 21.
In the seal member 15, the tubular portion 21a of the core metal 21 is fixed to the inner peripheral surface of the shaft hole 12a of the final case 12 via the outer peripheral portion 36 of the sealing portion 22, and the shaft of the first core metal ring portion 21b. It is attached so that the inner side surface in the direction is in contact with the side surface of the final case 12.

The main lip 32 extends from the inner peripheral side of the main body 31 to the axle 11 side and the sealed space A side. A peripheral groove 32a is formed on the outer peripheral surface of the main lip 32. A spring ring 23 called a garter spring is mounted on the peripheral groove 32a. The spring ring 23 tightens the main lip 32 inward in the radial direction.

The main lip 32 comes into contact with the outer peripheral surface of the first cylindrical portion 51a of the metal ring 51 with a tightening margin to prevent the sealing fluid in the sealing space A from leaking to the outer side B. In the free state, the main lip 32 has a substantially V-shape in which the cross-sectional shape inside the main lip 32 becomes thinner in the radial direction (the width dimension in the axial direction becomes smaller). The inner peripheral surface of the main lip 32 has a first inclined surface 32b on the outer side in the axial direction and a second inclined surface 32c on the sealing space A side.

The first inclined surface 32b is inclined so that the inner diameter becomes larger toward the outer side in the axial direction, and the second inclined surface 32c is inclined so that the inner diameter becomes larger toward the sealed space A side. The minimum diameter portion (top) of the main lip 32, which is a boundary portion between the first inclined surface 32b and the second inclined surface 32c, is referred to as a lip tip portion 32d. The first inclined surface 32b of the main lip 32 comes into contact with the outer peripheral surface of the first cylindrical portion 51a of the metal ring 51 and functions as a sealing surface.

The first auxiliary lip 33 extends outward from the main lip 32 in the axial direction from the inner peripheral side of the main body 31 to the axle 11 side and outward in the axial direction. The tip of the first auxiliary lip 33 is in contact with the outer peripheral surface of the first cylindrical portion 51a of the metal ring 51 with a tightening margin. The first auxiliary lip 33 mainly prevents muddy water and the like from entering the sealed space A.

The second auxiliary lip 34 extends outward from the first auxiliary lip 33 in the axial direction from the inner peripheral side of the main body 31 to the axle 11 side and outward in the axial direction. The tip of the second auxiliary lip 34 is in contact with the outer peripheral surface of the first cylindrical portion 51a of the metal ring 51 with a tightening margin. The second auxiliary lip 34 mainly prevents muddy water and the like from entering the sealed space A.

As shown in FIGS. 2 and 3, the side lip 35 extends from the axially outer side surface 31a of the main body portion 31 toward the annular plate portion 51c side of the metal ring 51, and extends to the axial inner side surface 51d of the annular plate portion 51c. Are in contact.
The side lip 35 is a cylindrical portion (second cylindrical portion) 35a extending from the side surface 31a of the main body portion 31 and a conical ring extending from the axially outer end portion of the second cylindrical portion 35a toward the annular plate portion 51c while expanding in diameter. An annular shape having a conical cylinder portion 35b having a shape and a lip portion 37 extending substantially radially outward from the axially outer end of the conical cylinder portion 35b in a state of being elastically curved and in contact with the annular plate portion 51c. It has an annular portion 35c of. The annular portion 35c is in contact with the annular plate portion 51c in an elastically curved state.

As shown in FIG. 2B, the lip portion 37 is a portion of the ring portion 35c facing the annular plate portion 51c, which is in contact with the annular plate portion 51c, and is outside the facing surface 35d. The peripheral edge 38 is included. That is, the outer peripheral edge 38 of the side lip 35 is always in contact with the annular plate portion 51c.
When the outer peripheral edge 38 is in contact with the annular plate portion 51c, it becomes difficult for muddy water or the like to enter between the side lip 35 and the metal ring 51. Therefore, the side lip 35 and the metal ring 51 are less likely to slide in a state where muddy water or the like is caught, and as a result, the side lip 35 is less likely to be worn.
At this time, in the lip portion 37, it is preferable that the outer peripheral edge 38 has the peak of the contact surface pressure with respect to the sleeve 16. As a result, muddy water and the like are less likely to enter between the side lip 35 and the metal ring 51. Further, it is suitable for maintaining the contact surface pressure on the annular plate portion 51c of the outer peripheral edge 38 for a long period of time even if the side lip 35 wears over time.
The peak position of the contact surface pressure of the lip portion 37 with the annular plate portion 51c can be determined, for example, by FEM analysis or the like.

The portion of the facing surface 35d that is radially inner of the lip portion 37 has a gap S between it and the annular plate portion 51c. When the facing surface 35d comes into contact with the metal ring 51 with the gap S, it is possible to prevent the contact area of the lip portion 37 from becoming excessively large.
Further, the sealing device 10 maintains the sealing property for a long period of time by having the gap S and the side lip 35 in contact with the annular plate portion 51c having the annular portion 35c and the conical cylinder portion 35b. Can be done.
Since the side lip 35 is used in an environment exposed to muddy water or the like, it cannot be avoided that the side lip 35 is gradually worn by sliding with the sleeve 16. Here, if the side lip 35 has the above-mentioned shape, even if the side lip 35 wears over time and the size of the tightening allowance changes, the angle of the ring portion 35c with respect to the conical cylinder portion 35b changes. By doing so, it is possible to absorb and maintain the state in which the outer peripheral edge 38 of the annular portion 35c is in contact with the annular plate portion 51c. Therefore, it is possible to maintain a state in which muddy water and the like are less likely to enter between the side lip 35 and the sleeve 16, and the side lip 35 is less likely to be worn over a long period of time.
In the annular portion 35c of the side lip 35, the angle θs formed by the facing surface 35d of the gap S portion and the annular plate portion 51c can be set in the range of, for example, 5 to 45 °.

The side lip 35 has, for example, the shape shown in FIG. 3 in the free state before contacting with the sleeve 16. The side lip 35 in the free state has a cylindrical base end portion 41, a conical ring-shaped intermediate portion 42, and a conical ring shape having a different inclination angle with respect to the axis of the axle 11 from the intermediate portion 42, in order from the main body 31 side. Has a tip 43 of the. Further, the space between the base end portion 41 and the intermediate portion 42 and the space between the intermediate portion 42 and the tip portion 43 are bent, respectively.

As shown in FIG. 2A, the side lip 35 having such a free state comes into contact with the sleeve 16 in an elastically curved state, and a part of the intermediate portion 42 and the tip portion 43 form an annulus. The portion 35c is formed, the remaining portion of the intermediate portion 42 constitutes the conical cylinder portion 35b, and the base end portion 41 constitutes the second cylindrical portion 35a.

In the free side lip 35, the length L1 in the axial direction C from the side surface 31a of the main body 31 to the tip edge 43a (hereinafter, also referred to as the total length of the side lip) is set to, for example, about 9.1 mm. There is.

The intermediate portion 42 extends obliquely outward in the axial direction and outward in the radial direction from the outer end portion in the axial direction of the base end portion 41. The inclination angle θ1 of the intermediate portion 42 with respect to the axis of the axle 11 is, for example, about 37 °. The angle θ1 can be set, for example, in the range of 30 to 45 °.
The length (width) L2 of the intermediate portion 42 in the axial direction C is, for example, about 3.5 mm, and in this case, it is about 38% of the total length L1 of the side lip 35. The length L2 can be set, for example, in the range of 30 to 45% with respect to the total length L1.

The tip portion 43 extends obliquely outward in the axial direction and outward in the radial direction from the outer end portion in the axial direction of the intermediate portion 42. The inclination angle θ2 of the tip portion 43 with respect to the axis of the axle 11 is, for example, about 17 °, and the angle θ2 is smaller than the angle θ1. The angle θ2 can be set, for example, in the range of 10 to 30 °.
The length (width) L3 of the tip portion 43 in the axial direction C is, for example, about 2.7 mm, and in this case, it is about 30% of the total length L1 of the side lip 35. The length L3 can be set, for example, in the range of 30 to 45% with respect to the total length L1.

The tip portion 43 extends obliquely from the axially outer end portion of the intermediate portion 42, and the angle θ2 is set to a value smaller than the angle θ1. Such a tip portion 43 prevents the contact state between the side lip 35 and the sleeve 16 from becoming a so-called abdominal contact state even if the tightening allowance of the side lip 35 is increased, and the lip portion 37 is on the outer peripheral edge. It is suitable for contacting the annular plate portion 51c so as to include 38.

On the other hand, as shown in FIG. 4A, in the side lip 65 having the base end portion 61, the intermediate portion 62 and the tip portion 63, the side lip 65 without bending between the intermediate portion 62 and the tip portion 63. When the tightening allowance is increased, as shown in FIG. 4 (b), the contact state between the side lip 65 and the sleeve 16 is such that the outer peripheral edge 63a on the tip side of the side lip 65 is between the sleeve 16. There will be a gap. When the wheel rotates in such a state, the side lip 65 slides with the sleeve 16 with muddy water or the like entering between the side lip 65 and the sleeve 16, and in this case, the side lip 65 wears in a short period of time. It ends up.
The sealing device 60 shown in FIGS. 4A and 4B has the same shape as the sealing device 10 shown in FIGS. 2 and 3 except for the side lip 65. Therefore, the members other than the side lip 65 are given the same reference numerals as those of the sealing device 10.

In the sealing device 10, it is important that the lip portion 37 includes the outer peripheral edge 38 in that the side lip 35 is less likely to be worn. Further, it is also useful that the peak of the contact surface pressure of the side lip 35 in contact with the sleeve 16 with respect to the sleeve 16 is located on the outer peripheral edge 38 in terms of suppressing the wear of the side lip 35.

The side lip 35 has a tightening allowance and is in contact with the sleeve 16. In the sealing device 10, the tightening allowance can be set relatively large, and the axial dimension L4 from the axial inner side surface 51d of the annular plate portion 51c to the tip edge 43a of the side lip 35 in the free state (see FIG. 3). For example, it can be 2 to 5 mm. The tightening margin L4 is more preferably 2.8 to 4.4 mm.

When the tightening allowance L4 for the sleeve 16 of the side lip 35 is increased, the total length L5 of the base end portion 41 and the intermediate portion 42 in the axial direction C of the free side lip 35 is from the side surface 31a of the main body portion 31. It is preferable that the distance L6 in the axial direction C to the inner side surface 51d of the annular plate portion 51c is longer. In this case, it is more suitable to set the tip edge 43a of the tip 43 as the peak of the contact surface pressure with respect to the sleeve 16.

[Performance evaluation of sealing device]
The sealing properties of the sealing device 10 and the sealing device 110 shown in FIG. 5 of the present embodiment were evaluated based on the time until oil leakage occurred.
The sealing device 10
Material: Sealing part 22 and elastic part 52 are NBR, core metal 21 and metal ring 51 are SPCC,
Dimensions: The inner diameter L7 of the main lip 32 is 47.5 mm, the inner diameter L8 of the first auxiliary lip 33 is 49.5 mm, the inner diameter L9 of the second auxiliary lip 34 is 48.3 mm, and the overall length L1 of the side lip 35 is 9. 1 mm,
This is a sealing device assembled by fitting the sealing member 15 having the above configuration to the sleeve 16. In the sealing device 10, the tightening allowance of the main lip 32 is 1.9 to 2.7 mm, and the tightening allowance L4 of the side lip 35 is 2.98 to 4.24 mm.

As shown in FIG. 5, the sealing device 110 includes an annular core metal 121, a sealing portion 122 fixed to the core metal 121, and an annular spring ring 123, and the main lip 132 and the third lip 132, which are in sliding contact with the sleeve 116, respectively. A sealing device including a sealing member 115 having 1 auxiliary lip 133, a 2nd auxiliary lip 134, and a side lip 135, and a sleeve 116 including a metal ring 151 and an elastic portion 152.
Material: Sealing part 122 and elastic part 152 are NBR, core metal 121 and metal ring 151 are SPCC,
Dimensions: The inner diameter L10 of the main lip 132 is 49.1 mm, the inner diameter L11 of the second auxiliary lip 134 is 49.9 mm, the height L12 of the side lip 135 is 5.3 mm,
This is a sealing device assembled by fitting the sealing member 115 having the above configuration to the sleeve 116. In the sealing device 110, the tightening allowance of the main lip 132 is 1.94 mm, and the tightening allowance of the side lip 135 is 0.8 mm.

Evaluation method and results The testing machine equipped with a pseudo axle and housing and filled with oil in the housing is equipped with the sealing device, and the testing machine is operated under the following conditions to determine the time until oil leakage occurs. It was measured.
(1) Muddy water is attached to the sealing portion, and then the muddy water is dried.
(2) The tester is operated at a rotation speed of 5 to 15 min ^-1 for 1 hour while the muddy water is dry.
(3) After the operation of (2) above is completed, the operation is stopped for several minutes, and the presence or absence of oil leakage is visually observed.
(4) In the operation patterns (1) to (3) above, the test machine was operated at a pace of 60 to 74 hours / week until an oil leak was observed.
As a result, oil leakage was observed in the sealing device 110 after about 1000 hours of operation. On the other hand, in the sealing device 10 of the present embodiment, no oil leakage was observed even after 1500 hours of operation, and the test was completed at that time.
From this test result, it became clear that the sealing device 10 of the embodiment of the present invention can prevent oil leakage for a long period of time.

(Other embodiments)
The embodiment of the present invention is not limited to the above embodiment, and the dimensions, materials, shapes, relative arrangements, etc. of the components can be appropriately changed within the scope of the present invention.
For example, in the first embodiment, in the side lip in the free state, the base end portion extends substantially horizontally toward the annular plate portion 51c side, but the base end portion is on the annular plate portion 51c side and radially outside. It may extend diagonally toward.
Further, the sealing device of the present invention can be used for agricultural machinery other than tractors, and can also be used for agricultural machinery such as combines, tillers, and rice transplanters.

10: Sealing device, 11: Axle, 11a: Flange, 12: Final case (housing), 12a: Shaft hole, 13: Bearing, 14: Bevel gear, 15: Sealing member, 16: Sleeve, 21: Core metal, 22 : Sealing part, 23: Spring ring, 31, 71: Main body part, 32: Main lip, 33: First auxiliary lip, 34: Second auxiliary lip, 35: Side lip, 35a: Second cylindrical part, 35b: Cone Cylinder part, 35c: Ring part, 37: Lip part, 38: Outer peripheral edge, 41: Base end part, 42: Intermediate part, 43: Tip part, 43a: Tip edge, 51: Metal ring, 51a: First cylinder Part, 51c: Circular plate part, 52: Elastic part, A: Sealed space, B: External side, S: Gap

Claims (3)

It is used to seal the annular space between the inner peripheral surface of one end of the shaft hole for inserting the axle provided in the housing and the outer peripheral surface of the axle.
A seal member fixed to the inner peripheral surface of one end of the shaft hole,
A sleeve having a cylindrical portion fitted to the outer peripheral surface of the axle and an annular plate portion having an annular shape in contact with a flange portion provided on the axle is provided.
The sealing member is an axle sealing device for agricultural machinery having an annular main lip in contact with the cylindrical portion and an annular side lip in contact with the annular plate portion.
The side lip has a conical ring-shaped conical cylinder portion whose diameter is enlarged on the annular plate portion side and a lip portion in contact with the annular plate portion, and is radially curved from the conical cylinder portion. A conical ring including an annular ring-shaped annular portion extending outward, and in a free state, an annular base end portion and a conical ring extending from the base end portion toward the annular plate portion and having an enlarged diameter on the annular plate portion side. A sealing member having an intermediate portion of the shape and a conical ring-shaped tip portion extending from the intermediate portion toward the annular plate portion, and a part of the intermediate portion and the tip portion form a sealing device for an axle. The inclination angle of the tip portion of the side lip on the annular plate side surface with respect to the axis of the axle is the inclination angle of the intermediate portion of the surface of the annular plate portion side with respect to the axis of the axle. Smaller, the tip length is 30-45% of the total length of the side lip.
The lip portion includes at least the outer peripheral edge of the surface of the annular portion facing the annular plate portion.
Of the surface of the annular portion facing the annular plate portion, the portion radially inner of the lip portion has a gap between the annular portion and the annular plate portion. apparatus. The axle sealing device for agricultural machinery according to claim 1, wherein the tightening allowance of the side lip to the sleeve is 2 to 5 mm. The axle sealing device for agricultural machinery according to claim 1 or 2, wherein the length of the intermediate portion is 30 to 45% of the total length of the side lip.

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