JPS61266861A - Friction-stepless speed change gear - Google Patents

Abstract

PURPOSE:To simplify the captioned gear by providing one length of crank- shaped spring material whose one end is engaged with a speed change ring and whose the other end is engaged with an output shaft, thereby automatically shifting the speed change ring from the high speed side to the low speed side as the load torque increases. CONSTITUTION:One end E1 of a spring material SP, which is formed into the shape of a crank, is engaged with a casing CG, while the other end E2 of SP is engaged with a speed change ring RG. In addition, a part CA of SP, which corresponds to a crank arm portion of a crank, is fitted into a slot ST made in the casing CG. With a load torque given, the spring material SP is twisted, since the crank arm part CA acts as a torsion bar. With this contrivance, the structure of the main part of an automatic speed change mechanism can be simplified, and moreover the manufacturing cost can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Use: The present invention provides a friction continuously variable transmission that automatically increases the rotation ratio (rotational speed of input shaft/rotational speed of output shaft) as load torque increases. Regarding.

Conventional technology: The transmission system from the input shaft to the output shaft includes a plurality of conical rotors that perform planetary motion. A conical rotor is provided with a concave transmission surface that frictionally engages the transmission wheel and a flat transmission surface that frictionally engages the raceway ring, and the rotation of the speed change ring or the rotation of the raceway ring is transmitted to the output shaft. A continuously variable friction transmission of this type is disclosed in Japanese Patent Publication No. 13221/1983.

FIG. 6 shows the main part of this type of device. In this figure, OR is a conical trochanter, RG is a speed change ring, and O8 is a conical surface whose effective radius can be changed as the speed change ring RG moves.
AS is a transmission wheel that frictionally engages the transmission wheel DW on the input shaft, F
S is a flat transmission surface that frictionally engages the raceway ring TH. In the following, in order to simplify the expression, the above type transmission will be simply referred to as an R-type transmission.

In the above transmission, as the speed change ring RG is moved from the top of the conical surface aS to the bottom of the conical surface aS, the rotational speed of the output shaft decreases, and at this point the rotational speed of the output shaft becomes 0. A mechanism for automatically moving the speed change ring RG in the low speed direction as the load torque increases is disclosed in Japanese Patent Application Laid-Open No. 59-656.
Those described in Japanese Patent Application Laid-open No. 56-65657 and Japanese Patent Application Laid-open No. 59-65657 can be employed.

Problems to be Solved by the Invention: The R-type transmission has a very wide range of applications, for example, it is used in light vehicles such as golf carts, centrifuges, agitators, screw tightening devices, and instruments such as viscosity measuring instruments. In order for the shift ring to move automatically, it is necessary to provide the optimum shift characteristics for each application. Therefore, from the standpoint of the manufacturer, it is extremely important to provide the speed change ring moving device with a configuration that can easily meet the various required characteristics. There are many unsatisfactory points in this regard.

Means for Solving the Problems According to the present invention, the transmission system from the input shaft to the output shaft includes a plurality of conical rotors that perform planetary motion, and are commonly frictionally engaged with one speed change ring. The conical trochanter is provided with a conical surface that frictionally engages with the transmission wheel on the input shaft, a concave transmission surface that frictionally engages with the transmission wheel on the input shaft, and a flat transmission surface that frictionally engages with the raceway ring. In a type in which the rotation of the raceway ring is transmitted to the output shaft, a series of spring members formed in the shape of a crank and engaged with the speed change ring at one end and the casing or the output shaft at the other end is provided. The present invention is characterized in that a mechanism for automatically moving the speed change ring from the high speed side to the low speed side as the load torque increases is constructed using the series of spring materials described above.

Function: The above-mentioned series of spring members formed into a crank-like shape are elements that twist the crank arm portion by a load torque. The crankshaft portion of the crankshaft is engaged with the speed change ring, and moves along an arc as the load torque changes, imparting axial movement to the speed change ring. The movement given to the speed change ring is said to be "in the direction of decreasing the rotational speed of the output shaft when the load torque increases." The angle φ at which the crank arm portion of the spring material is twisted by the load torque T is a function of the number N of spring materials and the diameter d. T and φ
In many cases, the automatic transmission characteristics determined by N can be achieved only by selecting N.

Addition and removal of spring material to standardized and manufactured transmissions (N
) is an operation that can be easily performed while taking into account the customer's request characteristics.

Example: In Figures 1 and 2, the rotation of the orbit ring TH is caused by the output shaft O.
A case is shown in which the present invention is applied to an R-type transmission that takes out 8 rotations. In these figures, SP is a spring member shaped like a crank.

The shape of the spring material SP and the manner in which the spring material SP is engaged with the speed change ring RG and the casing CG are shown enlarged in FIG. As shown in this figure, the spring material sp has one end E1 engaged with the casing CG, the other end E2 engaged with the speed change ring RG, and the crank arm portion OA fitted with the throttle 1-8T on the casing CG. It is being SR is a snap ring that prevents the part OA of the crank arm from escaping from the slot ST.

In the case shown, the number of spring materials Sp used is 4, and the slot ST
, the number of holes H1 on the casing CG into which the end E of the spring material SP is to be fitted, and the number of holes H2 on the speed change ring RG into which the end E2 of the spring material SP is to be fitted.
The number is 8.

The spring material SP is twisted by a load torque while using the crank arm portion OA as a torsion bar.

FIG. 4 shows a state in which the portion CA is twisted by φ due to the load torque, and the speed change ring RG is moved by Δ in the axial direction XX.

The above-mentioned spring material sp for automatic gear shifting can also be provided for an R-type transmission in which the rotation of the gear ring R() is transmitted to the output shaft O8, as shown in FIG. can. In this case, the track link TR is an element fixed to the casing CG, and the output shaft OS is a hollow shaft, but the automatic speed change action by the spring material SP is completely different from that shown in Figs. 1 and 2. The same is true.

The number of holes Hj + H2 and slots ST for attaching the spring material sp can be increased as appropriate.

Effects of the Invention In the above-mentioned device according to the present invention, the automatic transmission mechanism has a simple shape, requires less materials, is lightweight, and is easy to attach and detach, and the main parts of the automatic transmission mechanism are constructed at low cost using spring materials that can be easily mass-produced. Ru. The characteristics of the automatic transmission performed by this device can be adjusted to the required characteristics by appropriately adding or subtracting the spring material.

The gear shifting characteristics of this gear do not change over time, and since its operation is performed with extremely low friction loss, it has extremely high responsiveness to load fluctuations.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal side view showing an example of a friction continuously variable transmission according to the present invention, and FIG. 2 shows a state in which the spring material in the friction continuously variable transmission of FIG. 1 is rotated υ by a load torque. FIG. 3 is a side view, and FIG. 3 is a vertical cross-sectional view showing the shape and installation state of the spring material, and FIG. 4 is a diagram showing the action of the crank arm portion of the spring material being twisted by load torque to move the speed change ring in the axial direction. FIG. 5 is a longitudinal sectional side view showing an example of the frictionless continuously variable transmission according to the present invention, and FIG. 6 is a longitudinal sectional view showing the main parts of the R-type transmission. Figure 2 R・

Claims (1)

[Claims] The transmission system from the input shaft to the output shaft is composed of a plurality of conical rotors that perform planetary motion, and a conical surface that frictionally engages in common with one speed change ring and a transmission wheel on the input shaft. A conical rotor is provided with a concave transmission surface that engages and a flat transmission surface that frictionally engages with the raceway ring, and the rotation of the speed change ring or the rotation of the raceway ring is transmitted to the output shaft. A series of springs are formed in the shape of a crank and have one end engaged with the speed change ring and the other end engaged with the casing or output shaft. A continuously variable friction transmission characterized in that a mechanism for automatically moving to a lower speed side is constructed of the above series of spring materials.