JPS59187168A - Gear and attaching and detaching of gear to shaft - Google Patents

Abstract

PURPOSE:To permit to attach a gear to a shaft in one touch by a method wherein a pawl, projected into the radial direction of a bearing at a part of fixing pawl extended from the bearing of the gear, is formed integrally with the bearing so as to be deflectable toward the radial direction thereof. CONSTITUTION:The gear part 4 and the bearing part 6 of a gear 2 are formed integrally. A shaft hole 5, into which a shaft 1 is inserted, is penetrated through the bearing part 6, an indexing surface 9 is recessed at one side of the shaft hole 5 and a fixing pawl 7 is protruded at a position spaced apart from the surface 9 by a space 10. The fixing pawl 7 is formed with an engaging part 7-1 and the pawl part 7-2 and the whole of fixing pawl 7 is formed so as to be deflectable toward the radial direction of the bearing part 6. Accordingly, when the attaching shaft 1 is inserted into the shaft hole 5, the fixing pawl 7 deflects toward outside and permits the insertion of the shaft 1, subsequently, the pawl part 7-2 engages with a groove 8 provided on the shaft and, thus, the gear 2 is attached to the attaching shaft 1.

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a gear structure that fixes a gear to a shaft without using an E-type retaining ring or the like when attaching the gear to the shaft, and a method for attaching and detaching the gear to the shaft. It's about how to do it.

(Prior art) The O gear 15 shown in Fig. 8 shows a conventional gear mounting structure on the shaft.
was attached to the fixed shaft 16 by an E-type retaining ring 18 that fits into a groove 17 provided in the fixed shaft 16. According to this mounting structure, in order to attach the gear 15, an E-type retaining ring 18 is used. A ring 18 is required.

In addition, in order to fit the E-type retaining ring 18 into the groove 17 of the fixed shaft 16, it is necessary to use a jig called an E-type holder. 18 parts and miscellaneous expenses for installing the E-type retaining ring 18 are required.

Furthermore, there are restrictions on the E-type retaining ring, including its dimensions, the thickness of the shaft, the shape of the groove, etc.

FIG. 9 is a diagram showing the shapes of the E-type retaining ring 18 and the fixed shaft 16. It is assumed that a standard E-type retaining ring 18 is attached to a fixed shaft 16 provided with a groove 17. Dl is the diameter of the fixed shaft 16, D2 is the diameter of the groove 11 portion of the MLL thin shaft 16, and C is the width of the groove 11.

If the DJ is larger than the standard, the E-shaped holder will hit the fixed shaft 16, making it difficult to attach the E-shaped retaining ring 18. Also, when removing, as shown in Figure 10(a),
Since the E-type retaining ring 18 is hidden in the groove 17, it is difficult to remove it. When Dl is made smaller than the standard, the E-type retaining ring 18 is attached to the fixed shaft 1, as shown in Fig. 10(b).
6, the E-type retaining ring 18 wobbles in the direction of the arrow and becomes unstable.

If D2 is made larger than the standard, E at the time of installation
The deformation of the retaining ring 18 becomes large, and the E-shaped retaining ring 18 attached to the eaves becomes difficult to come off, but a large force is required to remove it. .

If D2 is smaller than the standard, installation can be easily done with small force, but it is likely to come off.

If C is larger than the standard, groove 17 and E-type retaining ring 1
8, and the E-type retaining ring 18 becomes unstable.

If C is smaller than the standard, install E stopper ring 18,
Removal requires a large amount of force.

As mentioned above, the fixed shaft 16. If the shape of the groove 17 deviates from the standard, it will be difficult to attach and remove the E-type upper ring 18, and the reliability of the gear will also decrease. Furthermore, if a non-standard E-type retaining ring is used, an increase in cost cannot be avoided. Furthermore, even when a standard E-type retaining ring was used, it was difficult to remove the E-type retaining ring once it was attached to the shaft.

(Objective) An object of the present invention is to provide a gear that can be attached and detached with one touch around the gear without using a mounting member such as an E-type retaining ring.

The present invention is characterized in that a mounting pawl that can be displaced in the radial direction of the bearing portion of the gear is formed integrally with the bearing portion.

(Example) Preferred embodiments of the present invention will be described below.

FIG. 1 is a cross-sectional view showing a gear attached to a filter shaft in one embodiment of the present invention, and FIG. 2 is a cross-sectional view showing the structure of the gear.

Reference numeral 1 denotes a shaft having a groove 8 on a part of its circumference and to which a gear 2 is attached. Reference numeral 2 denotes a gear, and a gear portion 4 provided with toothed teeth 3 and a bearing portion 6 having a smaller outer diameter than the gear portion 4 are integrally provided. In a part of the bearing part 6, there is a space 1 inside the bearing part 6.
A deformable attachment claw 7 is integrally provided at o1. This attachment claw 7 has a hook part 7-1 extending longer than eight sides of the bearing part 6, and a claw part 7-2 that engages with the groove 8 of the shaft 1. The mounting claw 7 is flexible in the radial direction of the bearing portion 6. 5 is the shaft hole of the gear 2. Reference numeral 9 denotes a contact surface on which the mounting claw 7 can be deflected to the maximum in the direction shown by the broken line.

FIG. 3 is a perspective view of the claw portion of the gear. The lower surface of the claw portion 7-2 of the mounting claw 7 is sloped 7-3. Also,
A space 10 exists between the mounting claw 7 and the contact surface 9.

FIG. 4 is a sectional view of the gear 2 being attached to the shaft 1. When the gear 2 is pushed in by applying a force in the direction of arrow A, the lower surface 7-3 of the claw portion 7-2 of the gear 2 receives a force from below the upper end of the shaft 1. The lower surface of the claw portion 7-2 has a slope 7-
3, a force in the direction of arrow B is applied to the claw portion 7-1, causing it to bend as shown in the figure.

The state shown in FIG. 5 is obtained by applying further force to push the gear 2 in this state. The mounting claw 7 is bent and multiplied by the axis 1 p.
I'm raising it. When the gear 2 is further pushed in, the claw portion 7-2 comes into the groove 8 of the shaft 1. At this time, the claw portion 7-2 is pressed against the shaft 1 by the elasticity of the resin material, so
The claw portion 7-2 is fitted into the groove 8 of the shaft 1, and the state shown in FIG. 1 is maintained.

As explained above, by providing the gear with an integrally molded resin pawl, the E-type retaining ring that was previously required is no longer necessary, and the gear can be attached to the shaft with a single touch. can.

In addition, when removing the gear attached to the shaft, as shown in Figure 6, the claw part 7-1 is held up by applying a force in the direction of arrow B, and the claw part 7-2 is attached to the shaft 1. Arrow C when removed from groove 8
By moving the gear 2 in the direction, the gear 2 can be removed from the axis l. At this time, the deflection of the mounting claw 7 is
regulated by.

(Effects) As described above, according to the gear mounting structure according to the present invention, the shape of the shaft can be selected without being restricted by standards, like when an E-type retaining ring is used when mounting a gear. This has the effect of reducing the assembly cost of nine parts, and once the gear is attached, it is much easier to remove than before. Furthermore, since the deflection of the mounting claw 7 is regulated by the angle 9, even if the claw is accidentally hooked with too much force on the portion 7-1, the base of the claw is protected and damage is prevented. Furthermore, when lubrication is required between the shaft and gears, by using the space 10 as an oil sump, there is no need to provide an oil groove on the shaft 1, which reduces costs and saves a lot of oil. can hold,
Effective in preventing wear.

Applying the present invention, a gear can be fixed to a shaft.

FIG. 7 is a perspective view showing this situation. A hole portion 11 is provided in the shaft hole 5 of the gear. The rotating shaft 12 is provided with an axial groove 13 as shown in the figure, and when the rotating shaft 12 is inserted into the shaft hole 5 of the gear, the hole 11 of the shaft hole 5 of the gear is inserted into the shaft hole 5 of the gear. Fits into the groove 13. In this state, if the claw part 7-2 of the gear is fitted into the groove 14 of the shaft, the rotating shaft 12
gears can be fixed to.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the present invention, in which a gear is attached to a shaft. FIG. 2 is a sectional view showing the structure of the gear. FIG. 3 is a perspective view of the area around the mounting claw in FIG. 2. FIG. 4 is a sectional view showing a state in which the gear is being attached to the shaft. FIG. 5 is a sectional view showing a state in which the gear is further pushed in from FIG. 4. FIG. 6 is a sectional view showing the state of the attachment claw when removing the attached gear. FIG. 7 is a perspective view of the gear mounting pawl turn 9 showing how the gear is fixed to the rotating shaft. FIG. 8 is a sectional view showing a conventional method of attaching a gear to a shaft. FIG. 9 is a perspective view showing the shape of an E-type retaining ring and a shaft to which the E-type retaining ring is attached. FIGS. 10(a) and 10(b) are perspective views showing the E-type retaining ring attached to the shaft. 1... Shaft 2... Resin gear 4... Gear part 6... Bearing part 7
...Mounting claw 18...L-shaped retaining ring or more Fig. 2 Fig. 3 Fig. 4 Fig. 6 Fig. 7 Fig. 101 (b)

Claims (1)

[Scope of Claims] (1,) A gear in which a bearing portion having a diameter smaller than the outer diameter of a gear portion having teeth on its outer periphery is connected to a side surface of the gear portion, the bearing portion having teeth on its outer periphery. A part of the long-extending mounting claw is provided with a claw part that protrudes in the radial direction of the bearing part, and the bearing part is provided inside the bearing part so that the mounting claw can be bent in the radial direction of the bearing part. A gear characterized by being formed integrally with. (2) In the method of attaching and detaching a gear to a shaft having a groove in at least the circumferential direction, when the gear is attached to the shaft, the bearing part has a smaller diameter than the outer diameter of the gear part and is bent in the radial direction. The gear is inserted into the shaft while being bent in the radial direction of the bearing part by aligning the mounting pawl formed integrally with the bearing part on the inside of the shaft with the outer peripheral surface of the shaft, and the gear is mounted in the groove. When the front gear is disengaged from the shaft by engaging the claw portion of the claw, the mounting claw, which is longer than the bearing portion, is extended in the radial direction of the bearing portion. A method for attaching and detaching a gear to and from a shaft, characterized in that the gear is disengaged from the groove and the claw portion and then pulled out.