KR200309174Y1 - Belt-driven type continuously variable transmission - Google Patents

Abstract

Rather than using a conical pulley to vary the diameter of the pulley on which the belt is fastened, the pulley pieces that divide the pulley into a number of pieces are moved radially concentrically with the axis of rotation to change the diameter of the cylindrical pulley itself. Belt-driven continuously variable transmission designed to change the diameter of the circle.

Description

Belt-driven continuously variable transmission {Belt-driven type continuously variable transmission}

The present invention relates to a continuously variable transmission, and more particularly, to a belt driven continuously variable transmission in which a continuously variable transmission is performed according to a change in the diameter of a circle formed by a plurality of pulley pieces.

Continuously variable transmission (CVT) refers to a transmission without a shift shock, literally "without a shift stage", following conventional manual transmissions and fluid automatic transmissions. The typical image of a continuously variable transmission is a smooth acceleration without shift shock. It has sufficient power performance and good fuel efficiency, which are difficult to realize in conventional fluid automatic transmissions.

In contrast to the conventional automatic transmission, the continuously variable transmission is continuously shifted between the top speed ratio and the minimum speed ratio to an infinite stage in accordance with a given shift pattern, so that the transmission can be operated to obtain the excellent power performance and fuel efficiency improvement using the engine's power to the maximum. to be. In other words, as a device capable of continuously controlling the speed ratio of the car has the following advantages.

□ It is easy to drive and there is little shifting shock.

□ Shifting to suit the driving conditions of the vehicle, improves power performance.

□ The fuel economy is improved by driving according to the shift pattern to travel along the lowest fuel consumption.

□ It is the basis of integrated power train control that maximizes engine output characteristics.

The continuously variable transmission is basically divided into belt driven, traction driven and hydraulic motor / pump combinations. Among them, the belt driving method has a lot of research because of its simple structure and low cost. There are rubber belt type, metal belt type, and metal chain type in the belt driving method, each having its own advantages and disadvantages.

Such a belt driving method is a method in which the belt is driven between the driving pulley (engine side) and the driven pulley (axle side) so that the diameters of the driving pulley and the driven pulley are varied so as to perform a shift between the driving side and the driven side without permission.

Conventionally, such a belt driving method is a conical shape of the drive pulley and the driven pulley as shown in FIG. According to this method, the conical drive pulley 1 and the driven pulley 3 are installed in the mutually displaced direction, and the belt 2 is connected between them. When the engine is started, the belt 2 is connected to the large diameter portion of the drive pulley 1 and the small diameter portion of the driven pulley 3 so that high speed, low torque is transmitted to the driven pulley 3, and as the speed increases, the belt When the 2 'is automatically moved to the position of the imaginary line in Fig. 1, the belt 2' is connected to the large diameter portion of the driving pulley 1 and the small diameter portion of the driven pulley 3, so it is a low torque but a high speed torque. It is transmitted to the driven pulley 3. (The continuously variable transmission described in FIG. 1 is extremely conceptualized and is actually operated by many components and control elements.) Thus, the belt driven continuously variable transmission of FIG. In this case, the shift is performed in infinite steps by the change of the contact radius between the belt and the pulley.

However, in the continuously variable transmission of FIG. 1, since the rotating surface of the pulley is inclined, the belt cannot be vertically connected, and thus, power cannot be transmitted efficiently. There is. In particular, in order to solve the heat problem, the conventional belt driven continuously variable transmission includes a separate cooling device.

In order to solve the above problems, the present inventors have searched for a method of changing the diameter of the cylindrical pulley itself rather than using a conical pulley to change the diameter of the pulley to which the belt is applied. By moving the pulley pieces divided by the radially concentric with the rotation axis, a structure that can change the diameter of the circle formed by each pulley piece was devised.

1 is a principle explanatory diagram of a conventional belt driven continuously variable transmission.

2a and 2b is a front view and a side view for explaining the principle of the belt driven continuously variable transmission according to the present invention.

3A and 3C are front and side views of one embodiment of the present invention.

Figure 4 is a side view of another embodiment of the present invention.

Figure 5 is a side view of another embodiment of the present invention.

<Description of Drawing>

Rotating plate 11 Drive shaft 12 Pulley piece 13 Belt 15 Pulley piece Rotating plate 17 Pulley piece moving rack 19 Pinion 21 Support plate 23 Insertion groove 25a, b, c Rotating shaft 27 )

<Basic Principle>

Figure 2a is a front view of the rotating plate 11 and the variable pulley (the driving side and the driven side are the same) of the basic components of the present invention, Figure 2b is a side view.

A plurality of pulley pieces 13 are radially installed on the rotating plate 11 concentric with the drive shaft 12 of the rotating plate 11. Here, each pulley piece 13 is radially reciprocable on the rotating plate 11 (in the direction of the arrow in Figs. 2A and 2B). These pulley pieces 13 form a circle to form a variable pulley. Then, the belt 15 is caught on the circumferential surface formed by the pulley pieces 13. Therefore, the stepless speed change becomes possible by changing the diameter of the variable pulley by controlling the distance that the pulley piece 13 linearly moves on the rotating plate 11.

Here, the number of pulley pieces 13 constituting the variable pulley is arbitrary. The lower the cost, the better, but the better, the smoother the belt will turn. In the specification, about eight are described as suitable, but this is a problem to be selected according to the design style.

As described above, in the present invention, since the circumferential surface of the variable pulley formed by the pulley piece 13 and the belt 15 can be closely adhered to each other (that is, the rotating surface is not inclined as in the conventional conical shape), the friction of the belt is reduced and is quiet. And efficient power transmission

Meanwhile, in order to concretely realize the basic concept of FIGS. 2A and 2B, there are matters to be considered as follows.

1) How to move each pulley piece linearly to form variable pulley,

2) How to secure the rigidity of pulley piece with one fixed point.

Hereinafter, specific examples to realize these problems will be described.

Example 1

Each pulley piece can be moved by a motor as one of the linear movement methods of each pulley piece. FIG. 3A shows a front view of the rotating plate 11 and FIG. 3B shows a side view of the rotating plate 11.

As shown in Figs. 3A and 3B, a pulley piece rotating plate 17 rotating radially at right angles to the rotating direction of the rotating plate 11 is provided radially inside the rotating plate 11. One pulley piece 13 is attached to each pulley piece rotating plate 17, and the pulley piece rotating plate 17 is controlled by a motor to rotate forward / reverse within a predetermined distance range. That is, the central axis C of each pulley piece rotating plate 17 is driven by a motor (including a gear box), and each motor is controlled forward / backward by the controller (ECU or TCU).

Alternatively, the pulley piece rotating plate 17 may be used as a gear to drive a worm gear system or the like by a motor.

Example 2

The second embodiment is similar to the configuration of the first embodiment, but uses a rack / pinion mechanism instead of the pulley piece rotating plate 17. As shown in Fig. 4, a rack / pinion mechanism is installed inside the rotating plate 11. When the pinion 21 is rotated by a motor (not shown), the pulley piece moving rack 19 can be linearly moved. Therefore, as the forward / reverse rotation of the motor is controlled, the pulley piece 13 can reciprocate radially with respect to the center point 12 of the rotating plate 11.

Example 3

Embodiment 3 is an embodiment for securing the rigidity of the pulley piece 13, which is an embodiment that can be combined with both the first embodiment and the second embodiment. In the method shown in FIGS. 1A-4, the fixed point of the pulley piece 13 was one place. Therefore, the rigidity that can overcome the pulling force of the belt caught on the pulley piece 13 is required.

In order to secure the rigidity, a supporting plate 23 as shown in FIG. 5 was added. The support plate 23 rotates by the rotary shaft 27 connected to be rotated by the drive shaft 12 of the rotary plate 11 and moves linearly (in the H direction in FIG. 5) toward or away from the rotary plate 11. You can use a spline structure.

The horizontal movement of the support plate 23 (that is, the movement in the H direction in FIG. 5) may be made by a solenoid (not shown). In addition, a plurality of insertion grooves 25a, b, and c are formed in the support plate 23 at positions corresponding to the pulley pieces 13 on the surface facing the pulley pieces 13. The positions of the insertion grooves 25a, b, and c should correspond to the positions of the pulley pieces 13 which are variable as the gear shifts, and the number of the grooves 25a, b, and c will be determined according to the gear shift stage (only three of them are shown in FIG. 5 for convenience). .

Under this structure, when shifting, i.e., when the pulley piece 13 moves radially on the rotating plate 11, the solenoid is operated by the controller (in the case of automobiles, the ECU or the TCU can play this role), thereby supporting the support plate ( 23) is separated from the pulley piece (13). Then, after the pulley piece 13 is moved to a new shift position, the solenoid is operated again to move the support plate 23 so that the insertion groove of the support plate 23 engages with the pulley piece 13.

As a result, in this embodiment, since the fixing point of the pulley piece 13 is two places on the rotating plate 11 side and the supporting plate 23 side, the rigidity can be further increased. In this embodiment, the insertion groove is required, so it is applicable to the case of stepped automatic shifting rather than continuously shifting.

As described above, according to the present invention, since the circumferential surface of the variable pulley and the belt can be closely adhered to each other, friction of the belt rotating by the variable pulley is reduced, resulting in a quiet and efficient power transmission compared to the conventional belt driven continuously variable transmission. It becomes possible. In addition, since the heat generation is reduced, a separate cooling device as in the conventional CVT is unnecessary.

Claims (5)

In the transmission that transmits the drive side power to the driven side, Rotating plate 11 rotated by drive shaft 12, A plurality of pulley pieces 13 radially installed on the rotary plate 11 concentrically with the drive shaft 12 and capable of linearly reciprocating radially on the rotary plate 11, Consists of the belt 15 is caught on the circumferential surface formed by the plurality of pulley pieces 13, Belt pulley type continuously variable transmission, characterized in that for changing the diameter of the circle formed by the pulley piece (13) by controlling the distance reciprocating radially on the rotating plate (11). The method according to claim 1, A pulley piece rotating plate 17 rotating radially at right angles to the direction of rotation of the rotating plate 11 is radially installed inside the rotating plate 11, and each pulley piece rotating plate 17 is reciprocated within a predetermined distance to the motor. Controlled by forward / reverse rotation, Belt pulley type continuously variable transmission, characterized in that one pulley piece (13) is attached to each one of the pulley piece rotating plate (17). The method according to claim 2, The pulley piece rotating plate (17) is a belt-driven continuously variable transmission, characterized in that the worm gear that is rotated by the rotation of the motor. The method according to claim 1, Pulley piece moving rack 19 is radially installed inside the rotating plate 11, each pulley piece moving rack 19 is a linear reciprocating motion by the pinion 21 of the motor to reciprocate within a certain distance range And Belt pulley type continuously variable transmission, characterized in that one pulley piece (13) is attached to each one of the pulley piece moving rack (19). The support plate according to any one of claims 1 to 4, wherein the support plate rotates linearly toward or away from the rotary plate 11 while being rotated by the rotary shaft 27 connected to be rotated by the drive shaft 12 of the rotary plate 11. (23) is further included, The support plate 23 is formed with a plurality of insertion grooves (25a, b, c) in the position corresponding to the pulley pieces 13 on the surface facing each of the pulley pieces 13, When it is time for the pulley piece 13 to move radially on the rotating plate 11, the support plate 23 is separated from the pulley piece 13, and the support plate 23 is moved after the pulley piece 13 is moved to a new shift position. It is coupled to the rotary plate 11, characterized in that the insertion groove of the support plate 23 is coupled to the pulley piece (13), belt-driven continuously variable transmission.