JPH0793798B2 - Starter motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is used for starting an engine, such as an engine for agriculture, an engine for lawnmowers, or the like, in which a rotary shaft is set vertically. The present invention relates to a starter motor whose drainage structure is improved.

[Prior Art] When starting a diesel or gasoline engine,
A starter motor coupled to the engine via a clutch mechanism or the like is driven so that the engine is rotated by the starter motor. In such a starter motor, there is a possibility that water will invade the inside of the water that is to be exposed to water, and therefore it is constructed with a simple waterproof structure. However, when there is a large amount of water, or when the starter motor is operating, there is water from the mechanism that extracts the rotational power.
This water infiltration into the motor reaches the commutator part in particular, and causes the brush to wear early and the motor to rotate badly due to rusting of the brush spring.

As means for solving such a problem, for example, as shown in Japanese Utility Model Laid-Open No. 59-47256 and Japanese Patent Laid-Open No. 61-121738, a structure for draining water is attached to a motor case or the like. I am trying to set it.

For example, when the rotating shaft is set in a horizontal state like an engine set in an automobile or the like, the rotating shaft of the starter motor is also set in a horizontal state, and the water draining structure shown in the above publications or the like can be adopted. However, in other general-purpose engines such as engines for agricultural equipment and engines for lawnmowers, the rotation axis of the engine may be set to the vertical state, and the rotation of the starter motor that starts this engine The axis is also set to the vertical state.

In the starter motor used by setting the rotary shaft in the vertical state in this way, an opening for draining water is formed in the end frame which is the lower end portion of the motor,
A drain pipe such as a bim tube is attached to this opening.

In such a vertically used starter motor, the rotational force is taken out from the upper side of the starter motor, and the engine ring gear and the pinion of the overrunning clutch are provided above the motor housing. An opening for meshing with the gear is formed, and a commutator mechanism of this motor is formed below. Therefore, there is a high possibility that water will enter the inside of the motor when it is exposed to water, and the entered water will flow from the upper side into the end frame that covers the commutator mechanism section and will accumulate.
Therefore, for example, even if the end frame portion is provided with a drainage structure, the commutator and the brush and the brush spring portion in contact with the commutator are more likely to be covered with water.

[Problems to be Solved by the Invention] The present invention has been made in view of the above-mentioned problems, and particularly when the commutator mechanism is set in the vertical position with the commutator mechanism section downward, the invention has entered the housing. Even if water is effectively removed and even if it is exposed to water from below, it is possible to effectively prevent water from entering the commutator mechanism, and reliability against water is improved. It is intended to provide a starter motor that is improved.

[Means for Solving Problems] That is, in the starter motor according to the present invention,
A groove member is set on the outer peripheral portion of the commutator portion which is set coaxially with the rotor which is set in the vertical state and which is positioned below the rotor, and the bottom portion of the groove member is used for draining water. An opening is formed, and a tapered guide member is provided in this opening, and a water passage is formed in this guide member so as to communicate with a drain hole formed in the end frame. It is a thing.

[Operation] In the starter motor configured as described above, even if water enters from the clutch mechanism portion on the upper side of the motor housing, for example, this water is received and retained by the groove member portion. Then, the water staying in the groove member portion is discharged to the outside from the opening portion formed in the groove member. In this case, since the groove member is set on the upper side of the commutator mechanism portion of the motor, water from the upper side does not reach the commutator and further the brush mechanism portion, and especially the brush mechanism portion. The part is reliably protected from flooding. In addition, when water is received from below, the drain holes formed in the end frame are designed to communicate with the groove member through the water passage and the guide member. Does not reach the commutator and brush mechanism. Therefore, in particular, the brush mechanism portion is surely protected from water immersion, and its reliability is improved.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows the structure of the lower part of the starter motor which is to be installed and set in the vertical direction, and the upper part, which is not shown in the figure, has the same structure as a normal starter motor. There is.

That is, the rotor 11 of the starter motor has its rotation axis set in a vertical state, and the commutator 12 is set below the rotor 11 in a coaxial state. A cylindrical yoke 13 that also serves as a housing is set on the outer peripheral portion of the rotor 11, and an end frame 14 is provided in the opening below the yoke 13, both of which are integrated by bolts as appropriate. It is designed to be assembled and set. The lower ends of the shafts 16 of the rotor 11 and the commutator 12 are rotatably supported by bearings 15 formed on the end frame 14. Although not shown in the figure, the upper end of the shaft 16 is supported by the bearing portion of the housing, is led out to the outside as an output shaft, and is coupled to the rotating shaft of the engine through the clutch mechanism and the gear mechanism. It is supposed to be done.

A brush 17 is brought into contact with the outer peripheral portion of the commutator 12, and the brush 17 is held in a brush housing portion of a brush holder 18 made of, for example, synthetic resin. The brush storage portion is configured to be opened downward, for example, so that the brush 17 can be easily attached and set by removing the end frame 14. The stored brush 17 is held and set in the brush storage portion formed in the brush holder 18 by the cover plate 19. The lid plate 19 is the end frame 14
It is supported by a protrusion 20 formed on the inside of the brush, and by attaching the end frame 14, the brush housing portion is held in a closed state. Here, a brush spring 21 is inserted and set at the back of the brush 17 inside the brush storage part.
It is arranged that 17 is brought into contact with and held on the outer circumference of the commutator 12 at a specified pressure.

The brush holder 18 is formed in a ring shape so as to surround the outer peripheral portion of the commutator 12 as shown in the second drawing.
A brim 22 is provided on the outer peripheral portion of the brim 22. The brim 22 is sandwiched between the yoke 13 and the end frame 14, and the brush holder 18 is fixedly held while the end frame 14 is assembled to the yoke 13. I have to. In this case, a rubber ring 23 is appropriately interposed between the collar 22 and the yoke 13 so as to prevent water from entering from this joint portion.

The brush holder 18 has a first wall close to the outer periphery of the riser portion 24 between the rotor 11 and the commutator 12 portion.
25 is integrally formed, and the second wall 26 is integrally formed along the brim 22. These walls 25 and 26 are arranged so as to be concentric with the shaft 16 and surround the commutator 12 portion, and the upper ends thereof are positioned at least above the commutator 12.
A bottom surface 27 is set between the first and second walls 25 and 26, and a ring-shaped groove member 28 is formed so as to surround the commutator 12. The groove member 28 has a structure in which the commutator 12 and the brush 17 are protected from water immersion from above the motor housing.
The water is received before it reaches the department, and this water is retained.

The bottom surface 27 of such a groove member 28 is formed with an opening 29 for discharging water that will be retained in the groove member 28, and the end frame 14 is further provided with the opening 29. The drainage hole 30 is formed so as to be coaxial.

A guide member 31 is provided in the opening 29 toward the drain hole 30.
Are integrally formed. The guide member 31 is formed in a taper shape such that the inner diameter becomes smaller toward the lower end, and a through hole 32 is formed at the tip thereof so that it is opened toward the drain hole 30. ing. A cylindrical water passage is formed on the outer periphery of the tapered guide member 31.
33 is integrally formed, and the lower end of the water passage 33 is fitted in the drain hole 30.

That is, in the starter motor configured as described above, all the water from above can be received by the groove member 18 portion. In this case, the gap between the first wall 25 constituting the groove member 28 and the riser 24 is made sufficiently small so that the passage of water to the brush 17 part is sufficiently limited, so that the water is not exposed to water. Even if this motor is flooded, the commutator
12 and 17 parts of the brush are not flooded. Then, the water received by the groove member 18 is guided to the guide member 31 through the opening 29 and discharged to the outside through the drain hole 30.

Further, in the case of being exposed to water from below, this water is effectively blocked by the guide member 31 formed in a tapered shape, and does not enter the inside. Even if it gets in, the water will be stored in the groove member 18, and since the opening 29 and the drain hole 30 are coupled and connected by the water passage 33, water from below Water is a commutator
It does not go into 12 parts.

In such a starter motor, a ring gear and an opening for engaging with a pinion gear of an overrunning clutch are formed on the upper side of the housing, and there is a high possibility that water will infiltrate from this portion. . However, since this starter is installed and set in a vertical state as shown in this figure, the water that enters from the upper opening and flows toward the commutator 12 is as described above. It collects in the groove member 28 formed integrally with the brush holder 17 and is discharged to the outside through the opening 29.

In the above embodiment, the member integrally formed with the brush holder 17 is shown to be coupled to the discharge hole 30 formed in the end frame 14, but there is no particular need to do so.
It may be configured as shown in the figure.

That is, in this embodiment, the guide member tapered in the opening 29 formed in the groove member 28 portion of the brush holder 18.
Although 31 is formed, the through hole 32 of the guide member 31 is configured by the guide tube 35. A water passage 36 is formed in the discharge hole 30 of the end frame 14 so as to be formed integrally with the frame 14, and the upper end of the water passage 36 is set on the outer circumference of the guide cylinder 35. To do.

Even with this configuration, it is possible to reliably receive water from the upper side of the starter motor at the groove member 28, and even if there is water from below,
This water will surely prevent water from entering the commutator 12 part.

[Effects of the Invention] As described above, in the starter motor according to the present invention, particularly when the starter motor is set in the vertical state in which the commutator portion is on the lower side, water is leaked from the upper clutch and the opening of the gear component Such water is surely blocked and discharged on the upper side of the commutator portion. Moreover, even if water is received from the lower side, it is possible to reliably prevent water from entering from the lower side. Is reliably prevented, and the reliability of the starter motor can be effectively improved.

[Brief description of drawings]

FIG. 1 is a sectional structural view corresponding to a portion of line I-I in FIG. 2 for explaining the structure of a starter motor according to an embodiment of the present invention, and FIG. 2 shows a brush holder part of the starter motor. FIG. 3 is a view showing a plan configuration of a corresponding portion, and FIG. 3 is a sectional view of a drain hole portion for explaining another embodiment of the present invention. 11 …… Rotor, 12 …… Commutator, 13 …… Yoke, 14 …… End frame, 16 …… Shaft, 17 …… Brush, 18 …… Brush holder, 25,26 …… First and second Wall, 27 ... bottom,
28 …… groove member, 29 …… opening, 30 …… discharging hole, 31 …… guide member (taper), 32 …… through hole, 33,36 …… water passage.

Claims (2)

[Claims] 1. A rotor having a commutator set to a lower position, and a brush holder which holds a brush contacting an outer peripheral portion of the commutator and is located above a brush holder which is set on the outer periphery of the commutator. And a ring surrounded by first and second walls that are concentrically formed so as to extend to at least the upper side of the commutator, and a bottom surface is formed between the first and second walls. -Shaped groove member, an opening formed in a part of the bottom surface of the groove member, and formed from the periphery of the opening toward the end frame of the lower end surface portion of the rotor, and a through hole is formed in the lower end. And a guide member configured to reduce the passage by the tapered surface, and formed in the end frame at a position coaxial with the opening so as to be continuous with the water passage communicating with the through hole of the guide member. With drainage holes, The starter motor is characterized in that water that has entered from above is received by the groove member, collected in the opening, and discharged from a drain hole. 2. The starter motor according to claim 1, wherein the groove member is configured integrally with a brush holder that holds a brush pressed against the outer circumference of the commutator.