JPH036300Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a pulley mounting structure for a washing machine in which a pulley is mounted on the rotating shaft of a rotor blade.

[Conventional technology]

The washing machine generates water flow in the washing tank by rotating rotary blades installed at the bottom of the washing tank. In such a washing machine, as shown in FIG. 3, a rotating shaft 1 having rotary blades 7 attached to its upper end projects downward through a cylindrical bearing 5 attached to the lower surface of the bottom of a washing tank 4. Washable motor (not shown)
A pulley 2 that decelerates and transmits the rotation is fixed.

The bearing 5 is fastened to the bottom of the washing tank 4 with a bearing nut 6.

Further, the rotation of the washing motor is transmitted to the pulley 2 by a V-belt 8.

Then, as shown in FIG. 4, a screw hole 1b into which the mounting screw 3 is screwed is bored in the lower part of the rotating shaft 1, perpendicular to the axial direction, and the boss part 2 of the pulley 2
In a, a round hole 2c through which the rotating shaft 1 passes vertically is bored vertically, and a through hole 2b through which the mounting bolt 3 passes is bored horizontally at right angles to the round hole 2c.

Then, insert the lower part of the rotating shaft 1 into the round hole 2c,
A mounting bolt 3 is screwed into the screw hole 1b through the through hole 2b and is tightened and fixed.

[Problem that the invention attempts to solve]

In the conventional fixing structure of the pulley 2 using the mounting bolt 3, tensile stress caused by tightening and shear stress caused by the torque transmitted to the pulley 2 act on the threaded valley of the mounting bolt 3, resulting in stress concentration. Therefore, bolts made of general steel may cause damage during operation of the washing motor, and to withstand this, it is necessary to increase the diameter of the rotating shaft 1 as much as possible and the diameter of the mounting bolt 3, or to use bolts made of chrome-molybdenum steel, etc. The strength had to be increased by using special steel mounting bolts, which resulted in extremely high costs.

The purpose of the present invention is to eliminate the disadvantages of the conventional example,
By reducing the stress acting on the mounting bolts, damage to the mounting bolts is prevented and the durability is extended, and the diameters of the mounting bolts and rotating shaft are reduced, and the material of the mounting bolts can be made of ordinary steel. An object of the present invention is to provide a pulley mounting structure for a washing machine that leads to a reduction in manufacturing costs.

[Means for solving problems]

In order to achieve the above object, the present invention forms the lower end of the rotating shaft of the rotor blade into a tapered prismatic body with at least one side tapered below the slope. Drill a screw hole to
On the other hand, a tapered square hole that matches the prismatic body is provided in the lower part of the boss part of the pulley, and the prismatic body of the rotating shaft is inserted and fitted into the square hole, and a bolt through hole is drilled horizontally in the boss part of the pulley. The gist is that a mounting bolt is inserted into the screw hole of the rotary shaft and the screw is tightened.

[Effect]

According to the present invention, the tapered prismatic body formed at the lower end of the rotating shaft is fitted into the tapered square hole drilled in the boss part of the pulley, so that the rotating shaft is separated from the motor by this part. The mounting bolt, which receives most of the transmitted torque and passes through the bolt through hole drilled horizontally in the boss of the pulley and the screw hole drilled perpendicularly to the axis of rotation, receives a small amount of torque. The main role of the mounting bolt is only to support in the thrust direction, and the load is reduced.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

Fig. 1 is a longitudinal sectional front view showing the main parts of the pulley mounting structure of the washing machine of the present invention, Fig. 2 is an exploded perspective view of the same, and the same components as Figs. 3 and 4 showing the conventional example refer to the same reference. The symbols are attached.

In the figure, reference numeral 1 denotes a rotating shaft protruding from the bottom surface of the washing tank with rotary blades (not shown) installed at the bottom of the washing tank. This is the same as in the conventional example in that the lower part of the rotary shaft 1 is inserted into the round hole 2c of the boss part 2a of the pulley 2.

The lower end of the rotating embodiment 1 has a cross section with a vertical width of A, for example.
It is formed into a long rectangular rectangular prism 1a whose length is larger than the width B, and at least one side of the prism 1a is formed into a slope 1c, so that the whole has a tapered shape that tapers downward.

Note that the prismatic body 1a does not necessarily have to be a long rectangle, and may be a square.

Further, a screw hole 1b is bored in the cylindrical portion above the quadrangular prism 1a so as to be orthogonal to the axial direction. It is desirable that this screw hole 1b be provided parallel to the longer width A of the rectangular prism 1a. 9 in the diagram
is a chamfer formed around the opening of the screw hole 1b.

On the other hand, a round hole 2c (see FIG. 1) is provided in the boss portion 2a of the pulley 2, into which the cylindrical portion of the rotating shaft 1 is inserted;
Continuing with this, there is a tapered square hole 2 below which matches the square prism 1a of the rotating shaft 1.
d, and a bolt through hole 2b into which the mounting bolt 3 is inserted is laterally bored perpendicular to the round hole 2c.

In this way, in order to fix the pulley 2 to the rotating shaft 1, first fix the square prism 1a at the lower end of the rotating shaft 1.
is inserted into the square hole 2d of the pulley 2 and fitted, and the mounting bolt 3 is passed through the bolt through hole 2b of the pulley 2 and further screwed into the screw hole 1b of the rotating shaft 1 to be tightened and fixed.

Furthermore, as is clear from what has been said above,
When attaching the pulley 2 to the square prism 1a of the rotating shaft 1, since the square prism 1a and the square hole 2d of the pulley 2 have the same shape, it is necessary to match them so that their tapered surfaces abut. Since the bolt through hole 2b of the pulley 2 and the screw hole 1b of the rotating shaft 1 inevitably match, incorrect installation can be prevented and workability for installing the pulley 2 can be improved.

In the embodiment described above, the lower end of the rotating shaft 1 and the hole on the pulley 2 side into which it is fitted are square, but
Other polygonal shapes such as hexagons and octagons may be considered, and the tapered slope 1c may have not only one side but also two or three opposing sides.

Next, regarding the operation, when the washing motor is in operation, the rotation of the washing motor is transmitted to the pulley 2 via the V-belt, and the rotational torque is transmitted to the boss portion 2a via the square prism 1a of the rotating shaft 1. The torque is transmitted to the lower square hole 2d, and this portion receives the torque applied to the mounting bolt 3 in a distributed manner. In this case, the tapered slope portion has a particularly large joint area, and torque is easily transmitted.

As a result, the shear stress acting on the threaded valley of the mounting bolt 3 is several steps smaller than that of the conventional pulley mounting structure, and the main role of the mounting bolt 3 is to prevent the pulley 2 from coming off in the thrust direction. Even bolts made of small materials can maintain strength and durability.

[Effect of idea]

As mentioned above, in the pulley mounting structure of the washing machine of the present invention, most of the torque from the washing motor is received by the prismatic body at the lower end of the rotating shaft, and only a small torque is applied to the mounting bolt. Therefore, the diameter of the rotating shaft can be made small. In addition, the mounting bolts can be made of inexpensive general steel, and the cost reduction effect is extremely large.

In this way, the pulley mounting structure is strong and reliable, and it also has excellent assembly workability such as easy positioning.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional front view of the main parts showing one embodiment of the pulley mounting structure of the washing machine of the present invention, Fig. 2 is an exploded perspective view of the same main parts, and Fig. 3 is a vertical sectional front view showing the conventional pulley mounting structure. FIG. 4 is a longitudinal sectional front view of the main parts of the same. 1...Rotating shaft, 1a...square prism, 1b...screw hole, 1c...slope, 2...pulley, 2a...
Boss part, 2b... Bolt through hole, 2c... Round hole,
2d... Square hole, 3... Mounting bolt, 4... Washing tank, 5... Bearing, 6... Bearing nut, 7... Rotating blade, 8... V-belt, 9... Chamfered portion.

Claims (1)

[Scope of utility model registration request] The lower end of the rotating shaft of the rotor blade is formed into a tapered prismatic body with at least one side converging below the slope, and a screw hole is bored above the prismatic body perpendicular to the axial direction; A tapered square hole that matches the prismatic body is provided in the lower part of the boss part of the pulley, and the prismatic body of the rotating shaft is inserted and fitted into the square hole, and the prismatic body of the rotation shaft is inserted and fitted into the square hole, and the bolt through hole drilled horizontally in the boss part of the pulley rotates. A pulley mounting structure for a washing machine characterized by a mounting bolt inserted into the screw hole of the shaft and tightened.