JPH0118841Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a dust-proof structure of a reduction mechanism portion of an internal reduction type starter.

Figure 1 shows a conventional starter of this kind. In the figure, 1 is an internal reduction type starter, 2 is a DC motor, 3 is an intermediate machine frame, 4 is a front machine frame, and the rear of the intermediate machine frame 3. A DC motor 2 is attached to the end face,
The front end surface is integrally screwed to the front machine frame 4 with bolts (not shown). 5 is a yoke of the DC motor, 6 is a field pole fixed to the inner peripheral surface of this yoke, and 7 is an armature of the DC motor 2, in which the front end of the armature rotating shaft 8 is It protrudes through the intermediate machine frame 3 and is rotatably supported by a ball bearing 9 fitted to the intermediate machine frame 3. 1
0 is a spur gear formed at the front end of the armature rotating shaft 8, and is engaged with a large gear 12 that is spline-engaged on a pinion shaft (output rotating shaft) 11, and is driven. Reference numeral 13 denotes an overrunning clutch that is spline-engaged with a helical spline (not shown) formed on the pinion shaft 11 so as to be able to slide back and forth. It will be installed. Reference numeral 15 denotes a shift lever whose end is cam-engaged with the cam-engaging groove 13a of the overrunning clutch 13, and an electromagnetic switch (not shown) is attached to the other end (upper end).
It rotates around the rotation fulcrum portion 15a. 16 is a lever spring that presses the shift lever 15, 17
18 and 19 are sleeve bearings fitted into the intermediate machine frame 3 and the front machine frame 4, respectively, and pivotally connect the front and rear ends of the pinion shaft 11. It is supported by a shaft.

Next, the operation of the above configuration will be explained. When the shift lever 15 is biased to rotate in the counterclockwise direction in the figure about the pivot point 15a by an electromagnetic switch (not shown), the overrunning clutch 13, which is cam-engaged with the shift lever 15, moves on the pinion shaft 11. It is transferred forward (to the right in the figure), and the pinion 14 is engaged with a ring gear of an internal combustion engine (not shown). At the same time, the DC motor 2 is energized to generate rotational force, which is increased (the rotational speed is reduced) and transmitted to the pinion shaft 11 . This rotational force is then transmitted to the pinion 14 via the overrunning clutch 13, driving the ring gear and starting the internal combustion engine. After the engine is started, the shift lever 15 is returned to the state shown in the figure, the overrunning clutch 13 moves backward on the pinion shaft 11 (moves to the left in the figure), and the pinion 14 is disengaged from the ring gear, returning to the state shown and standing still.

The conventional device is configured as described above, but in this configuration, the reduction gear (consisting of the spur gear 10 and the large gear 12) is of an open configuration, so it is prone to dirt, abnormal wear of the teeth, etc. , there were drawbacks such as high meshing noise.

This idea was made in order to eliminate the drawbacks of the conventional device as described above, and the purpose was to provide the above-mentioned reduction gear with a dust-proof structure and to have the excellent effects described below. There is.

An embodiment of this invention will be described below with reference to the drawings. First, in FIG. 2, reference numeral 21 denotes an intermediate machine frame installed in place of the intermediate machine frame 3 described in the conventional device shown in FIG. There is. Note that the other features are the same as the conventional device shown in FIG. 1 above. Next, according to Figure 3, the second
A starter 20 incorporating the one shown in the figure will be explained. That is, in this starter 20, the intermediate machine frame 3 of the starter 1 shown in FIG. A closed space surrounded by the projecting portion 22, a lid 23 extending further inward from the lower end of the projecting portion, and the overrunning clutch 13 constitutes a dustproof mechanism. Note that g is a gap forming the labyrinth seal mechanism.

With the above configuration, the reduction gear mechanism is protected by the dust-proof structure, increasing the life of the device, preventing lubricating oil such as grease applied to the gears from scattering, and improving the speed of the reduction gear. Meshing noise is reduced.

As described above, according to this invention, the intermediate machine frame 3
, a cylindrical protrusion 22 protruding in the axial direction so as to surround the outer circumferential surface of the tooth portions of the reduction gear devices 10 and 12;
, and the opening on one side of this protrusion is directly pressed and closed by the end wall of the overrunning clutch 13 through the gap g when the overrunning clutch is at rest. In order to prevent dust from entering the gear chamber housing the gear devices 10 and 12, there is no need to manufacture a separate cover plate or closing plate that closes one side opening of the gear chamber as in the conventional case. Since the end wall of the overrunning clutch 13, which is at rest after the engine is started, is utilized, the assembly of the starter can be simplified and costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of the main parts of a conventional device, Fig. 2 is a front view a of the intermediate machine frame, which is the main component of this invention, and its sectional view b taken along the line B-B, and Fig. 3 is a part of the main component of this invention. FIG. 2 is a cross-sectional view of main parts showing an example. In the figure, 4 is the front machine frame, 8 is the armature rotation shaft, and 10
is a spur gear, 11 is a pinion shaft, 12 is a large gear, 1
3 is an overrunning clutch, 21 is an intermediate machine frame, 22 is a protrusion, and 23 is a lid body. Note that the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] Rotation of an output rotation shaft mounted between the front machine frame and the intermediate machine frame and bearing at both ends, and a DC motor that is attached to the intermediate machine frame and spaced parallel to this output shaft in the radial direction. a shaft, a reduction gear device installed between the two rotating shafts, and an overrunning clutch that is spline engaged with a helical spline formed on the output rotating shaft so as to be slidable back and forth; A cylindrical protrusion projecting in the axial direction is provided on the machine frame so as to surround the outer peripheral surface of the teeth of the reduction gear device, and one side opening of the protrusion is also used as the end wall of the overrunning clutch. An internal reduction type starter characterized in that the overrunning clutch is directly compressed and closed by the wall while the overrunning clutch is at rest.