JPH0219650Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a power transmission device using a non-circular gear train, and particularly to an inconstant speed rotating device that does not require balancing.

As shown in FIGS. 1 and 2, a power transmission device using non-circular gears has a pair of meshing non-circular gears 1 and 2 arranged between a drive source 3 such as a motor and an output mechanism 4. This converts constant speed rotational motion from the drive source 3 into inconstant speed rotational motion. For example, as shown in FIG.
is connected to the shaft 5 of the drive source 3, and a crank 7 is attached to the rotating shaft 6 of the other non-circular gear 2.
It is used when making a quick return movement. Such non-circular gear trains are capable of high-speed motion compared to those using cams, etc., but one factor that determines the limits of their operation is vibration due to the asymmetry of the non-circular gears themselves. In order to suppress this, the amount of imbalance caused by asymmetry was conventionally adjusted using counterweights. However, in the case of this counterweight, space is difficult,
Furthermore, since the unbalance amount is calculated using an approximate formula, it is difficult to achieve perfect balance.

The present invention aims to eliminate the drawbacks of such non-circular gears, and to provide an inconstant speed rotating device that does not require balance adjustment.

The inconstant speed rotating device according to the present invention which achieves this object includes a pair of non-circular gears having a point-symmetric shape with respect to the rotation center interposed between a drive source and an output section, and a pair of non-circular gears from the drive source. While giving a rotation speed of 1/2 of the required rotation speed to the output part on the driving side,
The present invention is characterized in that a speed increasing means for doubling the rotational speed is provided between the output section on the driven side of the non-circular gear pair.

Therefore, in the inconstant speed rotating device of the present invention, since the noncircular gear is point symmetrical about its rotation center, unbalance due to its rotation does not occur.
On the other hand, 1/2 rotation of the non-circular gear becomes one rotation of the output section by the speed increasing means, and the output section rotates at a predetermined non-uniform speed every rotation.

Hereinafter, the present invention will be explained in more detail with reference to FIGS. 4 to 8.

In FIG. 4, two meshing non-circular gears 11
and 12 are both symmetrical, and are point symmetrical about the center of rotation. A non-circular gear train that meshes point-symmetrically in this way is incorporated into a mechanism as shown in FIG. 5, for example. That is, in the figure, 13 is a drive source such as a motor, and 14 is an output mechanism, between which the non-circular gear train is installed. In this case, the drive source 13 and one non-circular gear A deceleration means 15 such as a deceleration gear is disposed between the output mechanism 14 and the other non-circular gear 12, and a speed increase means 16 such as a speed increase gear is disposed between the output mechanism 14 and the other non-circular gear 12. In this embodiment, these deceleration means 15
and the speed increasing means 16 are adjusted so that deceleration and speed increase are performed at the same ratio, and are set so that the speed reduction ratio is 1:2 and the speed increase ratio is 2:1. That is,
The speed reduction means 15 obtains a rotation speed that is 1/2 of the rotation speed required for the output mechanism 14, which is the output section, and the speed increase means 16 doubles the rotation speed of the non-circular gear 12 to obtain the required rotation speed. I'm trying to get it. This results in
The constant speed rotational motion of the drive source 13 is converted into inconstant speed rotational motion and transmitted to the output mechanism 14, but in this transmission, as will be described later, conventionally, one rotation of the non-circular gear provides one cycle of the output mechanism. One cycle of the output mechanism can be obtained with 1/2 rotation of the non-circular gear.

Figure 6 shows the state when meshed non-circular gears are used, where θ ₁ and θ ₂ are the rotation angles of each non-circular gear A and B, and r ₁ and r ₂ are the rotation angles of non-circular gear A. The distance between the center and the rolling contact point P and the distance between the center of the non-circular gear B and the rolling contact point P, d, is the distance between the centers of the non-circular gears A and B, and is constant. or,
O ₁ and O ₂ are the centers of each non-circular gear A and B, and a and b are pitch lines of each non-circular gear A and B. In such a non-circular gear train, the following equation (3) is satisfied while satisfying the rolling contact condition of constant center distance: r ₁ + r ₂ = d...(1) r ₁ dθ ₁ = r ₂ ddθ ₂ ...(2) Satisfies the transfer function of angular velocity ratio.

dθ ₂ /dθ ₁ = (θ ₁ ), (θ ₁ +2nπ) = (θ ₁ ), (n = integer) ...(3) From equations (1) to (3), θ ₂ = θ ₂ (θ ₁ )=∫〓 ¹ ₀ θ(ξ)dξ r ₁ = r ₁ (θ ₁ )=d {(θ ₁ ) / ((θ ₁ )+1)} r ₂ = r ₂ (θ ₁ )=d{1 /(θ ₁ )+1} is obtained, and θ ₂ , r ₁ , and r ₂ are each expressed by _an independent variable θ 1 of 1. Therefore, conventionally, when θ ₁ changes from 0 to 2π, θ ₂ also changes from 0 to 2π, and during this period (θ ₁ )
performs one cycle. On the other hand, in the present invention, the function g(θ ₁ )=(2θ ₁ ) with one period π can be used, and by setting g(θ ₁ )=dθ ₂ /dθ ₁ , θ ₂ =∫〓 ¹ ₀ g(ξ)dξ g(θ ₁ +nπ) = g(θ ₁ ) r ₁ = d{g(θ ₁ )/(g(θ ₁ )+1)} r ₂ = d{1/( g(θ ₁ )+1)} is obtained. In other words, when θ ₁ changes from 0 to 2π, θ ₂ also changes from 0 to 2π, but during this time g
(θ ₁ ) can perform two cycles. Then, the pitch radii r ₁ and r ₂ can be obtained as r ₁ (θ ₁ +nπ)=r ₁ (θ ₁ ) r ₁ (θ ₂ +nπ)=r ₂ (θ ₂ ). Figure 7 is a characteristic diagram of the conventional angular velocity ratio transfer function obtained by T as described above.
FIG. 8 is a characteristic diagram of the present invention.

Note that FIG. 9 is an example of another non-circular gear formed point-symmetrically with respect to the rotation center O.

As explained above, according to the present invention, since the non-circular gear is made point symmetrical with respect to its rotation center, the amount of unbalance caused by asymmetry can be reduced to "0", and balancing is not necessary. . Also, 1/2 rotation of the non-circular gear becomes one rotation of the output section by the speed increasing means, and as a result, the output section rotates a predetermined 1 rotation for each rotation.
Non-uniform rotation of cycles can be performed. Furthermore, since the output mechanism can be driven for one cycle with 1/2 rotation of the non-circular gear, there is also the effect that high-speed rotation performance can be further improved.

[Brief explanation of drawings]

Fig. 1 is a plan view of a conventional non-circular gear, Fig. 2 is a plan view of its use, Fig. 3 A and B are a plan view and side view of an example of its use, and Fig. 4 is an embodiment of the present invention. FIG. 5 is a plan view of an example of its use, FIG. 6 is a schematic diagram of the meshing state, FIGS. 7 and 8 are characteristic diagrams of the angular velocity ratio transfer function, and FIG. FIG. 3 is a plan view of the embodiment. 11, 12... Non-circular gear, 15... Reduction means,
16...speed increasing means.

Claims (1)

[Scope of utility model registration request] A pair of non-circular gears having a point-symmetrical shape with respect to the center of rotation is interposed between a drive source and an output part, and from the drive source to the driving side of the pair of non-circular gears, a rotation speed of 1/2 of the required rotation speed is provided to the output part. An inconstant speed rotating device, characterized in that a speed increasing means is provided between the output section on the driven side of the non-circular gear pair and the output section on the driven side of the non-circular gear pair.