JPS602536B2 - Pulley fixing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for fixing a pulley attached to a rotating shaft for power transmission in equipment equipped with rotating means such as a washing machine. Shaking due to the centrifugal force of time,
The purpose is to provide a strong attachment that will not come off.

FIG. 1 shows the schematic structure of a conventional two-drain type washing machine, in which numeral 1 denotes a washing tub into which laundry and water are put.

Reference numeral 2 denotes a washing motor, which is equipped with a motor pulley 3 on its rotating shaft.
, is transmitted to an invera pulley 5 made of resin via a V-belt 4.

Furthermore, the rotation of the invera pulley 5 is transmitted to the pulsator 7 via a rotating shaft (described later) that is kept watertight by an oil seal (not shown) in the metal case 6, and the rotation of the pulsator 7 washes the clothes. It will be done. The rinsing action is performed by rotating the pulsator 7 at the same time as during washing, but overflowing water during overflow rinsing passes through overflow pipe 8 to drain pipe 9 and exits the machine.

Further, drain water after washing and rinsing is similarly discharged to the outside of the machine via the drain pipe 9 when the cock 10 is opened. After washing and rinsing, the clothes are placed in a dehydration basket 11 and are dehydrated by the centrifugal force generated by the rotation of the dehydration motor 12.

Here, the installation structure of the invera pulley 5 will be explained with reference to FIG. 2.

Reference numeral 13 denotes the aforementioned rotating shaft, and a cutter split portion 13a is formed on a part of the circumferential surface of the rotating shaft.

The rotary shaft 13 is inserted into a boss part 14 provided at the center of the invera pulley 5, and the wall part 13 is formed so that the boss part 14 has an integrally formed hollow chest 15.
6 is formed. Reference numerals 17 and 18 are holes formed in the boss portion 14 and the wall portion 16, respectively, and the holes 17 and 18 are respectively formed in the boss portion 14 and the wall portion 16, and
The three parties including 3a are in a corresponding relationship.

Reference numeral 19 indicates a nut located within the same portion 15 of the cavity 8, and 201 indicates a nut located outside the wall portion 16.

Reference numeral 21 denotes a bolt which is screwed into the nuts 20 and 19 and has its tip end pressed against the cutter split portion 13a, and 21a indicates its head.

The nut 19 is in pressure contact with the inner surface of the wall portion 16 to strongly press the bolt 21 toward the rotating shaft 13, and the nut 20 is in pressure contact with the outer surface of the wall portion 16 to force the bolt 21 toward the rotating shaft 13 side. This is to prevent loosening. Here, the Invera pulley 5 repeats left and right rotation during washing, but if the Invera pulley 5 is made of resin such as nylon containing glass fibers, it will inevitably creep, especially the wall portion 16. is likely to occur.

When this creep occurs, the nuts 19 and 20 become loosened and the bolt 21 cannot be pressed into the rotating shaft 13 sufficiently. In addition to this, due to the rotation of the inverter pulley 5, a centrifugal force acts on the bolt 21 to try to separate it from the head 21a, and furthermore, as the left and right rotation is repeated as described above, the bolt 21 is forced to move in the direction of coming off. The rotational force of Such an effect occurs significantly when the above-mentioned creep occurs. Invera pulley 5
For example, if the bolt is made of aluminum die-casting, the occurrence of the above problem can be suppressed to some extent because there is no creep, but the problem still remains because centrifugal force acts in the direction of the bolt coming out. . If such a situation occurs, the tip end of the bolt 21 will separate from the cutter split portion 13a, and the rotating shaft 1 of the inbella booley 5 will be separated.
3, the pulsator 7 will not be able to rotate, and furthermore, there is a risk that the inverter pulley 5 will come off from the rotating shaft 13, which is a dangerous and extremely inconvenient situation.

In order to completely prevent such problems from occurring, it is possible to tighten the nuts 19 and 20 strongly, but if the tightening torque is too large, the wall portion 16 may crack or
There is a big risk of deformation. The present invention has been made in view of the above-mentioned conventional problems, and embodiments thereof will be described below.

In FIGS. 3 and 4, the same reference numerals as in FIG. 2 indicate the same members, and their explanations will be omitted.

13b is a screw hole formed through the rotary shaft 13 in a direction perpendicular to its length direction, and has a female thread cut on its inner circumferential surface.

Holes 14a and 14b are provided in the boss portion 14 of the invera pulley 5 to correspond to the openings at both ends of the screw hole 13b, and have a larger diameter than the screw hole 13b.

22 has a threaded portion 22a that is screwed into the screw hole 13b, a head 22b shaped like a lotus on one end side of the threaded portion 22a, and a tip portion 22c having a smaller diameter than the threaded portion 22a and shaped like a lotus on the distal end side of the threaded portion 22a. The bolt has a tip portion 22.
c into the screw hole 13b from one hole 14a, and then screw the screw portion 22a into the screw hole 13b.

This screwing is continued until the head 22b presses against the peripheral green part of the hole 14a. Here, the bolt 22 will be explained in more detail.

As shown in FIG. 5, the rotation center line 0 of the rotating shaft 13
10 to the heavy DK on the head 22b side.
If the distance at K' is 2, the mass on the head 22b side is the kite, and the grass on the tip 22c side is 2, then the desk.
〆． The relationship ＜Skin 2〆2 is established. In the above configuration, if the angular velocity of the Invera pulley 5 is
The relationship 2 of 2 is established, and the centrifugal force acts on the bolt 22 in the direction of its removal, that is, the thrust force in the advancing direction is stronger than the thrust force in the backward direction, which loosens the bolt 22 and causes the invera pulley to loosen. There is no fear that 5 will rattle or come off.

Further, there is no need to forcefully attach the bolt 22, and the boss portion 14 of the invera pulley 5 does not crack due to the vertical attachment of the bolt 22. Furthermore, even if the vertical bolt 22 is somewhat loose during assembly, it will not come loose due to the action of centrifugal force during use. Next, a specific example will be described.

According to an experiment, the angular velocity of the Invera pulley 5 in a two-pot type washing machine was 2,800 yen. Therefore, in Fig. 5, the total length L of the bolt 22 is 55 Yanagi (M6),
12.2 sails, 17.4 legs for evening 2, 4.02 evenings for desk, and 5.71 evening for desk 2. According to this, evening, desk. :
The ratio was 1:2.03, and about twice as much centrifugal force acted in the vertical direction of the bolt 22 as in the opposite direction.

The thickness T of the head 22b was 3 ribs, the thickness t of the peripheral wall of the boss portion 14 was 7 sides, and the flea D of the rotating shaft 13 was 12 ribs. In addition, as shown in the figure, the bolt 22 has a threaded portion 22.
If the tip portion 22c is formed with a smaller diameter than a, it will be easier to insert the bolt 22, and the bolt 22 will be easier to insert.
It is possible to completely prevent the threaded portion 22a from being screwed into the threaded hole 13b in an inclined state, and damage to the threads can be prevented.

Of course, if there is no problem in inserting the bolt 22, the threaded portion 22a may be formed over the entire length. Furthermore, if the dome 23 is integrally formed on the invera pulley 5 to hide the tip 22c of the bolt 22 in the screwed state, the string-like part 23 will not get caught on the tip 22c, and maintenance , it is possible to prevent fingers from accidentally getting caught during inspection, and the size of the closing opening 23a of this dome portion 23 is made smaller than the head 22b of the bolt 22, and the size of the closing opening 23a of the dome portion 23 is made smaller than that of the head 22b and the opening 23a. If the threaded portion 22a is set to a length that does not reach the screw hole 13b when it is in contact with the end face, assembly problems such as the bolt 22 being screwed in from the dome portion 23 side will not occur, and the bolt 2
The screwing direction of 2 can be seen at a glance, making work easier. Here, the constituent materials of the Invera pulley 5 include strength,
In consideration of the molding surface, it is preferable to use a resin material such as nylon or polypropylene mixed with glass fiber, but it may also be formed from aluminum die-casting or other metal materials.

In addition, although the installation of the invera pulley of a two-drain type washing machine has been described in the embodiment, it goes without saying that the pulley fixing structure according to the present invention can be implemented in other devices in the same manner as in this embodiment.

Further, it is preferable to mold the dome portion provided on the pulley integrally with the pulley in terms of productivity and ease of assembly, but it may also be molded separately and attached with screws or the like. Further, in this embodiment, a case has been described in which the rotary shaft is rotated by the rotation of the pulley, but it goes without saying that the configuration may be conversely configured such that the rotation of the rotary shaft is transmitted to the pulley. As described above, according to the pulley fixing device of the present invention, the bolt that connects the boss portion of the pulley and the rotating shaft is urged in the insertion direction (progressing direction) by the centrifugal force caused by the rotation of the pulley. This prevents the bolts from loosening and reliably prevents the pulley from rattling or coming off like in the past, and also eliminates the need to attach the bolts more vertically than necessary during assembly. When made of resin, the pulley can be effectively prevented from cracking.

[Brief explanation of the drawing]

Fig. 1 is a schematic vertical cross-sectional view of a conventional two-drain type washing machine, Fig. 2 is a cross-sectional view of the main parts showing the installation mechanism of the in-bear pulley, and Fig. 3 is the installation of the pulley in an embodiment of the present invention. FIG. 4 is an external perspective view of the pulley, and FIG. 5 is an enlarged sectional view of the main parts of the attachment portion of the pulley. 5... Invera pulley (pulley), 13... Rotating shaft, 13b... Screw hole, 14... Post part, 14a, 14b... Hole, 22... Bolt, 22a...
...screw part, 22b...head, 22c...tip part,
23...Dome part, 23a...Opening. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1. A boss portion for inserting a rotary shaft is formed in the central portion of the pulley, and a screw hole is formed in a portion of the rotary shaft in a direction substantially perpendicular to its length direction. Holes are formed in the boss portion so as to correspond to the openings at both ends of the screw hole, and a bolt is screwed into the screw hole and penetrates through the hole in the boss portion, and the head side of the bolt is attached to the boss portion. and the distances from the center of rotation of the rotating shaft to the center of gravity on the head side and tip side of the bolt are l_1 and l_2,
When the respective masses are m_1 and m_2, m_1
A pulley fixing device characterized in that it is configured such that the relationship l_1<m_2l_2 holds true. 2. Claim 1, characterized in that the bolt consists of a threaded portion that is screwed into the threaded hole of the head and shaft, and a tip portion that extends from the threaded portion to the tip side and has a smaller diameter than the threaded portion. Fixing device for the pulley described. 3. The pulley is equipped with a dome portion that hides and surrounds the tip end of the bolt that has passed through the hole in the boss portion, and when the tip end of the bolt is inserted through the side opening, the dome portion A pulley fixing device according to claim 1 or 2, characterized in that the head side of the bolt is brought into contact with the pulley, and the threaded portion of the bolt is formed so as not to reach the threaded hole of the rotating shaft. .