JPH0861143A - Engine with oil seal - Google Patents

Abstract

(57) [Summary] [Purpose] Prevents dust from entering the oil seal on the engine crankshaft. [Structure] A rear journal 7 of a crankshaft 6 is supported on a crankcase 1 via a bearing 3, a flywheel 11 is fixed to a rear protruding portion 8 of the crankshaft 6, and an annular oil seal 12 is attached to the bearing mounting cover 5. In an engine equipped with an oil seal, in which the inner lip portion 12a of the oil seal 12 is brought into contact with the peripheral surface 13 of the crankshaft 6,
The dustproof projection 15 was extended toward the front surface 14 of the.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine provided with an oil seal, which can prevent dirt and dust from entering the oil seal and prevent wear of the oil seal.

[0002]

BACKGROUND OF THE INVENTION The basic structure of an engine provided with an oil seal, which is the subject of the present invention, is as shown in FIG. 1 or 7.
A bearing housing hole 3a is formed in the rear wall 2 of the crankcase 1 of the engine E, the bearing 3 is fitted in the bearing housing hole 3a, and a bearing mounting cover 5 is fixed to the rear wall 2 of the crankcase 1. The cover 3 fixes the bearing 3 from the rear side, and the rear journal 7 of the crankshaft 6 is supported on the crankcase 1 via the bearing 3.
The flywheel 11 is fixed to the rearward protruding portion 8 of the above, an annular oil seal 12 is fitted into the bearing mounting cover 5, and the lip portion 12a inside the oil seal 12 is brought into contact with the peripheral surface 13 of the crankshaft 6. It is of the form.

[0003]

2. Description of the Related Art A prior art of this type is shown in FIG. 7, which has a large gap 16 between an oil seal 12 and a flywheel 11.

[0004]

In the above prior art, dust, mud or the like is likely to enter the sealing surface 18 between the lip portion 12a of the oil seal 12 and the peripheral surface 13 of the crankshaft 6 from the outside through the gap 16. There is a risk that the lip portion 12a of the oil seal 12 may wear and cause oil leakage. An object of the present invention is to prevent dust and the like from entering the oil seal of the crankshaft of this engine.

[0005]

Means for achieving the above object will be described below with reference to FIGS. 1 to 6 showing an embodiment. That is, the invention 1 is characterized in that, in the engine provided with the oil seal of the basic structure, as shown in FIG. 1, the dustproof projection 15 extends from the oil seal 12 toward the front surface 14 of the flywheel 11. To do.

A second aspect of the invention is to mount the rear wall 2 of the crankcase 1 and a bearing instead of extending the dustproof projection 15 from the oil seal 12 as shown in FIGS. The engine rear member 17 selected from the cover 5 and the rear end plate 10 attached to the rear wall 2 of the crankcase 1 and the front surface 14 of the flywheel 11 face each other, and the engine rear member 17 and the front surface of the flywheel 11 are opposed to each other. Of the fourteen, a dustproof projection 15 is provided so as to project from one opposite surface to the other opposing surface.

[0007]

[Action]

(1) In the first aspect of the invention, as illustrated in FIG. 1, since the dustproof projection 15 extends from the oil seal 12 toward the front surface 14 of the flywheel 11, the dustproof projection 15 and the front surface 14 of the flywheel 11 are provided. It is possible to sufficiently narrow the space 16 between them and to effectively prevent dust and mud from entering the sealing surface 18 between the lip portion 12a of the oil seal 12 and the peripheral surface 13 of the crankshaft 6 from the outside.

(2) In the second aspect of the invention, as shown in FIGS. 2 to 6, of the engine rear member 17 and the front surface 14 of the flywheel 11, the dustproof projection 15 is projected from one surface to the other surface. Since it is provided, it is possible to effectively prevent dust and mud from entering the sealing surface 18 between the lip portion 12a of the oil seal 12 and the peripheral surface 13 of the crankshaft 6 from the outside, as in the case of (1).

[0009]

In any of the first and second aspects of the invention, the dustproof projections can effectively prevent dust and mud from entering the sealing surface between the lip portion of the oil seal and the peripheral surface of the crankshaft from the outside. Therefore, it is possible to suppress wear of the lip portion of the oil seal and prevent oil leakage from the oil seal to the outside.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 is a vertical sectional view of a main part of a vertical multi-cylinder engine showing a first embodiment.

As shown in FIG. 1A, a bearing accommodating hole 3a is formed in a rear wall 2 of a crankcase 1 of a vertical multi-cylinder engine E.
Open, insert the bearing 3 into the bearing receiving hole 3a, and fix the bearing mounting 5 to the rear wall 2 of the crankcase 1,
The bearing 3 is fixed from the rear by the bearing mounting cover 5 which is exposed from the rear side. A rear journal 7 of a crankshaft 6 is supported on the crankcase 1 via a bearing 3 on the rear side, and a flywheel 11 is detachably fixed to a rearward projecting portion 8 of the crankshaft 6 via fastening bolts 19.

As shown in FIGS. 1 (A) and 1 (B), an annular oil seal 12 is fitted into the bearing case cover 5 so that the flywheel 11 is exposed from the front, and the oil seal 12 is inserted.
The lip portion 12a on the inner side of is contacted with the peripheral surface 13 of the crankshaft 6. From the oil seal 12 to the flywheel 11
A dustproof protrusion 15 extends rearward toward the front surface 14 of the.

The dustproof protrusion 15 extends rearward from the rear wall 12b of the existing oil seal 12 and extends along the bearing mounting cover 5 in the outer diameter direction, as shown by the meshed portion in FIG. 1B. And is formed into a block shape. Dustproof projection 15 and front surface 14 of flywheel 11
The gap 16 is 3 mm or less, preferably 2 mm or less, and more preferably 1 mm or less. This is because the smaller the gap 16 is, the more reliably the dust is prevented from passing through the mud.

Therefore, the function of the dustproof device of the first embodiment will be described. Since the dustproof protrusion 15 extends rearward from the oil seal 12 toward the flywheel 11, the dustproof protrusion 15 causes the oil seal 12 to be separated from the oil seal 12. The sealing surface 18 between the crankshafts 6 can be shielded from the rear gap 16. It is possible to effectively prevent dust or mud from entering the sealing surface 18 from the outside, prevent wear of the oil seal 12, and prevent oil leakage from the oil seal 12 to the outside. Further, in the first embodiment, since the dustproof protrusions 15 can be integrally molded when the oil seal 12 is molded, the dustproof protrusions 15 can be easily manufactured.

FIG. 2 shows a second embodiment, in which the above dustproof projection 1 is used.
Instead of forming the oil seal 12 on the oil seal 12 as in the first embodiment, the bearing 5 is integrally extended from the bearing mounting cover 5 toward the front surface 14 of the flywheel 11. That is,
The dustproof projection 15 is projected rearward from the bearing mounting cover 5 in an eaves-like shape so as to be close to the front surface 14 of the flywheel 11 (see the hatched portion in FIG. 2).
Thereby, the space 16 can be sufficiently narrowed.

FIG. 3 shows a third embodiment, and contrary to the second embodiment, an eave-shaped dustproof projection 15 is integrally extended forward from the front surface 14 of the flywheel 11 to the bearing case cover 5. Yes (see shaded area in Figure 3).

FIG. 4 shows a fourth embodiment of the present invention, which is based on the basic structure of the second embodiment, but a dustproof protrusion 15 which is a separate body is detachably fixed to the bearing mounting cover 5 with fastening bolts 21 for dustproofing. The projection 15 is projected rearward toward the front surface 14 of the flywheel 11.

FIG. 5 shows a fifth embodiment. While using the third embodiment as a basic structure, a separate dustproof projection 15 is detachably fixed to the front surface of the flywheel 11 with a fastening bolt 22, and the dustproof projection 15 is formed. Is projected forward toward the bearing mounting cover 5.

FIG. 6 shows a sixth embodiment of the crankcase 1
The dustproof protrusions 15 extend from the rear end plate 10 fixed to the rear wall 2. That is,
A separate dustproof protrusion 15 is detachably fixed to the side of the rear end plate 10 facing the bearing case cover 5 with a fastening bolt 23, and a bent wheel 24 of the dustproof protrusion 15 is supported by the bearing mounting cover 5 while the flywheel is being supported. A projection 15 for dust protection is projected rearward toward the front surface 14 of 11. The rear end plate 10 is for mounting a cell starter or the like.

In the fourth to sixth embodiments, the crankcase 1
The rear wall 2, the bearing mounting cover 5, the rear end plate 10 and other engine rear members 17 or the flywheel 11 are separately fixed, so that the existing engine rear member 17 and flywheel 11 are newly processed. There is no need, and the dustproof projection 15 can be simply provided.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a vertical multi-cylinder engine according to a first embodiment, FIG. 1 (A) is a vertical cross-sectional view of a main part, and FIG. 1 (B) is an enlarged view around an oil seal.

FIG. 2 is a view corresponding to FIG. 1B of an engine showing a second embodiment.

FIG. 3 is a view corresponding to FIG. 1B of a third embodiment.

FIG. 4 is a view corresponding to FIG. 1B of the fourth embodiment.

FIG. 5 is a view corresponding to FIG. 1B of the fifth embodiment.

FIG. 6 is a view corresponding to FIG. 1B of the sixth embodiment.

FIG. 7 is a view corresponding to FIG. 1 (B) of the related art.

[Explanation of symbols]

1 ... crankcase, 2 ... crankcase rear wall, 3 ...
Bearings 3a ... Bearing receiving holes, 5 ... Bearing case cover, 6 ... Crankshaft, 7 ... Rear journal, 8 ... Rear protrusion, 10 ... Rear end plate, 11 ... Flywheel, 12 ... Oil seal, 12a ... Lip part, 13 ... Circumferential surface of crankshaft, 14 ... Front wall of flywheel, 15 ... Dustproof protrusion, 16 ... Void, 17 ... Engine rear member, E ...
engine.

Claims (2)

[Claims] 1. A bearing housing hole (3a) is formed in a rear wall (2) of a crankcase (1) of an engine (E), and the bearing housing hole is formed.
The bearing (3) is fitted in (3a), the bearing mounting cover (5) is fixed to the rear wall (2) of the crankcase (1), and the bearing (3) is fixed by the bearing mounting cover (5) later. Fix and support the rear journal (7) of the crankshaft (6) to the crankcase (1) via the bearing (3), and attach the flywheel (11) to the rear protrusion (8) of the crankshaft (6). After fixing, insert the annular oil seal (12) into the bearing mounting cover (5), and contact the inner lip portion (12a) of the oil seal (12) with the peripheral surface (13) of the crankshaft (6). In the engine provided with the oil seal, the front surface of the flywheel (11) is separated from the oil seal (12).
An engine provided with an oil seal, characterized in that a projection (15) for dust prevention is extended toward (14). 2. An engine provided with an oil seal according to claim 1, wherein instead of extending the dustproof projection (15) from the oil seal (12), a rear wall (2) of the crankcase (1) is provided. ), Bearing mounting cover
(5) The engine rear member (17) selected from the rear end plates (10) attached to the rear wall (2) of the crankcase (1) and the front surface (14) of the flywheel (11) face each other. The engine rear member (17) and the flywheel
An engine provided with an oil seal, characterized in that a dustproof protrusion (15) is provided so as to project from one of the front faces (14) of (11) toward the other opposing face.