JP5220722B2 - Shaft seal structure of gear reducer - Google Patents

Description

  The present invention relates to a shaft seal portion structure of a gear reducer that prevents leakage of a lubricant from an output shaft of the gear reducer by an oil seal.

  Among many examples of damage to the oil seal of the gear reducer, there is damage to the sealing mechanism of the oil seal due to internal foreign matter. The internal foreign matter is wear powder generated mainly by the rotation of the gear. As this wear powder mixes with the lubricating oil during use and damages the sealing mechanism of the oil seal, oil leakage occurs and the machine, product and floor are soiled. Therefore, protecting the oil seal from damage caused by internal foreign matter is a conventional problem in a power transmission device filled with lubricating oil.

In order to solve such a problem, various means have been conventionally provided.
For example, as a technology that the applicant has conventionally implemented, there is a configuration in which a filter is attached between a pressure reducing portion provided by extending a gear case and an oil seal, and thus wear powder is filtered (Patent Document 1). reference).

JP2007-46653A

  However, in this prior art, the filter is formed with a center hole having an inner diameter that is in close contact with the outer peripheral surface of the output shaft so that the filter is in contact with the shaft. For this reason, over time, there have been problems such as damage to the shaft due to abrasion powder adhering to the filter, sliding marks on the shaft due to the filter, wear of the filter itself and formation of a gap between the shaft and the like. Of course, these cause oil leakage. Further, since the filter is in contact with the shaft, a slight loss torque is generated, which causes heat generation.

  Therefore, the present invention does not cause damage to the shaft due to the filter or wear powder adhering to the filter, while maintaining the same loss torque and heat generation as the conventional product not using the filter as described above, An object of the present invention is to provide a shaft seal structure of a gear reducer that achieves lubrication and long life.

In the present invention, a gear reduction mechanism having an output shaft is built in a gear case, lubricating oil for lubricating the gear reduction mechanism is enclosed in the gear case, and leakage of the lubricating oil from the output shaft is prevented by an oil seal. A shaft seal structure of a gear reducer for sealing,
The shaft seal structure includes a bearing that supports the output shaft, a bearing support portion and / or a bearing support member of the gear case that is located on the outer periphery of the bearing, the oil seal that is mounted in the vicinity of the bearing, An oil hole for guiding lubricating oil to the oil seal and a filter for filtering the lubricating oil;
The bearing comprises a shielding means at least on the inner side of the gear case,
The oil hole communicates with the gap between the bearing and the oil seal and the gear case internal space, and guides the lubricating oil to the oil seal. Or at least one bearing support member,
The filter is mounted so as to cover the opening of the oil hole ,
A shaft seal structure for a gear reducer, characterized in that at least one vent hole is formed above the output shaft to communicate the gap between the bearing and the oil seal and the internal space of the gear case . The above problem has been solved.

According to the present invention, lubricating oil leakage from the bearing is prevented, and wear powder generated inside the gear case is prevented from directly damaging the oil seal, while ensuring appropriate lubrication and extending the life of the oil seal. can do. In addition, since the filter is not in contact with the output shaft and is mounted at a non-sliding location, the shaft is not damaged by the filter or wear powder adhering to the filter, and wear of the filter itself is prevented. Can do. No extra torque loss or heat is generated.
Therefore, the configuration of the present invention achieves appropriate lubrication of the oil seal and long life of each member including the shaft and filter while realizing effective removal of wear particles by the bearing shielding means and the filter. Can do.

The front view containing the partial cross section of the geared motor which provided the shaft seal part structure of this invention. (A) is the 2-2 sectional view taken on the line of FIG. 1, and is the figure which shows the whole shaft seal part structure of Example 1 of this invention, (b) is the figure which looked at the shaft seal part from the gear case inside side. (A) is principal part sectional drawing of the shaft seal part structure of Example 1 of this invention, (b) is the figure which looked at (a) from the gear case inside side. (A) is principal part sectional drawing of the shaft seal part structure of Example 2 of this invention, (b) is the figure which looked at (a) from the gear case inside side.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows a geared motor having a gear reducer having the shaft seal structure of the present invention. As shown in FIG. 1, the geared motor 10 includes a motor unit 20 and a reduction gear unit 30, and the motor unit 20 and the reduction gear unit 30 are connected via a load-side bearing bracket 22 of the motor unit 20. ing.

  As shown in FIG. 1, the motor unit 20 includes a motor shaft 24 that is rotatably supported at both ends, and a frame 26. A load-side bearing bracket 22 that supports the load side of the motor shaft 24 via a load-side bearing 28 is attached to one end of the frame 26, and the anti-load side of the motor shaft 24 is opposed to the other end. An anti-load-side bearing bracket (not shown) that is supported via a load-side bearing (not shown) is attached.

  The load side of the motor shaft 24 extends through the load side bearing 28, and a worm 32 is formed on the outer periphery of the extension. The worm 32 is located in the gear case 34 of the reduction gear unit 30 and meshes with the worm wheel 36. Thereby, the motor shaft 24 functions as an input shaft of the reduction gear unit 30.

  As shown in FIGS. 1 and 2, the reduction gear unit 30 includes a gear case 34 and a bearing support member 38 that are attached to the load-side bearing bracket 22 of the motor unit 24.

  A worm wheel 36 that meshes with the worm 32 and an output shaft 40 connected to the worm wheel 36 are incorporated in the gear case 34, and the worm 32 and the worm wheel 36 constitute a gear reduction mechanism. The gear case 34 is filled with lubricating oil for lubricating the gear reduction mechanism.

Both ends of the output shaft 40 are rotatably attached by bearings 42 and 42 ′ incorporated in the gear case 34 and the bearing support member 38, respectively.
That is, in this embodiment, as shown in FIG. 2, in the left shaft seal portion structure, the bearing 42 is supported by the bearing support portion 34 a of the gear case 34, and the right shaft seal portion structure is separated from the gear case 34. The bearing is supported by a bearing support member (bearing bracket) 38.

  As shown in FIG. 2, the bearings 42 and 42 ′ are shielded on the inner side of the gear case by the shielding means 44 and 44 ′. Specifically, a single shield type bearing may be used, or a normal bearing may be mounted with a bearing metal seal. Thereby, it is possible to prevent leakage of the lubricating oil from the bearing as much as possible, and to prevent the abrasion powder generated inside the gear case from directly damaging the oil seal.

  However, if such a configuration is adopted, the oil seal may be insufficiently lubricated. Therefore, in the present invention, the following configuration is adopted, thereby ensuring appropriate lubrication while using wear powder or a filter. It is possible to provide a shaft seal structure that does not damage the oil seal or the shaft.

Fig.3 (a) is an enlarged view of the shaft seal part structure of the lower left part in FIG. An oil seal 46 for preventing leakage of lubricating oil in the gear case 34 is attached to the outside of the bearing 42 via a gap 48.
The oil seal 46 includes a lip 46a, a dust guard 46b, and a garter spring 46c. The lip 46a is pressed against the outer peripheral surface of the output shaft 40 by the tightening force of the garter spring 46c, and the lip 46a and the outer peripheral surface of the output shaft 40 are pressed. The sliding part between them maintains proper contact.

  In the first embodiment, an oil hole 50 extending in the output shaft direction is provided between the bearing 42 and the bearing support portion 34 a of the gear case 34 at the lower portion of the output shaft 40, and is formed between the bearing 42 and the oil seal 46. The air gap 48 communicates with the air gap 48. And the filter 52 is being fixed to the front of the bearing support part 34a with the volt | bolt 54 so that the opening part of this oil hole 50 may be plugged up. In addition, various methods such as fixing with an adhesive can be used for mounting the filter 52.

  The material of the filter 52 may be any material that can filter fine particles such as abrasion powder and permeate the lubricating oil, and is preferably composed of a nonwoven fabric made of a high-density porous member. .

Furthermore, if a vent hole is provided above the output shaft, the oil seal can be lubricated more smoothly.
As shown in FIGS. 2 (a) and 2 (b), in the first embodiment, the bearing 42 and the oil seal are positioned at a position (in the upper part of the output shaft 40) symmetrical with the oil hole 50 about the axis of the output shaft. A ventilation hole 56 communicating with the gap 48 between the 46 is provided. By adopting such a configuration, the air permeability between the bearing and the oil seal is enhanced, and the lubricating oil is more easily guided to the oil seal.
The vent hole 56 is used for venting air and is not easily affected by wear powder at a position away from the gear reduction mechanism, so that a filter may not be attached.

  The shaft seal structure on the other end can also have the same configuration as described above except that the filter 52 is mounted on the bearing support member 38.

In the second embodiment, the formation position of the oil hole 50 and the mounting position of the filter 52 are different from the first embodiment.
That is, as shown in FIG. 4A, the oil hole 50 extends from the gap portion 48 between the bearing 42 and the oil seal 46 toward the lower surface of the bearing support portion 34a, that is, oblique to the output shaft 42. The filter 52 is mounted on the lower surface of the bearing support portion 34a so as to close the opening. In addition, in FIG. 4, the example mounted | worn with the adhesive agent is shown.

As in the case of the first embodiment, the same configuration as described above can be adopted on the other end side, except that the filter 52 is mounted on the bearing support member 38. The filter mounting method, suitable material, and formation of air holes are the same as in the first embodiment.
In addition, the oil hole 50 and the vent hole 56 can be formed by combining the configurations as described in the first and second embodiments and other various types.
The geared motor has been described above as an example, but needless to say, the present invention can be used in general for a gear reducer that does not include a motor.

34: Gear case 34a: Bearing support part 38: Bearing support member 40: Output shaft 42: Bearing 44: Shielding means 46: Oil seal 48: Air gap part 50: Oil hole 52: Filter 56: Ventilation hole

Claims (1)

A gear reduction mechanism that includes a gear reduction mechanism having an output shaft in the gear case, and in which the lubricating oil for lubricating the gear reduction mechanism is enclosed in the gear case, and leakage of the lubricating oil from the output shaft is sealed by an oil seal. The shaft seal structure of the machine,
The shaft seal structure includes a bearing that supports the output shaft, a bearing support portion and / or a bearing support member of the gear case that is located on the outer periphery of the bearing, the oil seal that is mounted in the vicinity of the bearing, An oil hole for guiding lubricating oil to the oil seal and a filter for filtering the lubricating oil;
The bearing comprises a shielding means at least on the inner side of the gear case,
The oil hole communicates with the gap between the bearing and the oil seal and the gear case internal space, and guides the lubricating oil to the oil seal. Or at least one bearing support member,
The filter is mounted so as to cover the opening of the oil hole ,
Above the output shaft, at least one air hole for communicating the gap between the bearing and the oil seal and the internal space of the gear case is formed .
Shaft seal structure of gear reducer.

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