JP2005048940A - Continuously variable transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive and compact continuously variable transmission capable of reducing the number of pieces of components while using a belt type CVT or toroidal type transmission and a planetary gear reducer at the same time, and reducing the complicated control. <P>SOLUTION: Sun gears 1a, 2a are integrally connected with the same input shaft 1, a planetary gear 1b, an internal gear 1c, and a carrier 2a are mounted around the sun gear 1a, a planetary gear 2b, an internal gear 2c and a carrier 2d are mounted around the sun gear 2a, and the internal gears 1c and 2c are integrally rotatably connected with each other. The carrier 1d of a planetary gear mechanism transmits the rotation to a driven-side pulley 8 of a belt-type CVT through an intermediate gear 6, a gear 5 and a rotating shaft 9 to be rotated in the direction same as the input shaft 1, when a gear 7 fixed on the input shaft 1 for transmitting the input rotation is rotated, and the continuously variable gear shift is output from a planetary gear reducer by rotating a driving-side pulley 10 of the CVT integrally connected with the carrier 1d through a belt 11, and the carrier 1d. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

Detailed Description of the Invention

    The present invention relates to a continuously variable transmission capable of continuously changing a gear ratio as a speed control of a planetary gear mechanism using a belt-type CVT (Continuously Variable Transmission) or a trochoid type continuously variable transmission.

    Conventionally, a continuously variable transmission has limitations when a gear ratio is large or a large torque is transmitted when a belt type CVT or a toroidal type continuously variable transmission is used alone. Therefore, a continuously variable transmission is configured by using a belt type CVT or a toroidal type continuously variable transmission in combination with a planetary gear reducer.

Problems to be solved by the invention

    However, the belt-type CVT or toroidal type continuously variable transmission and planetary gear reducer described above are used in combination with clutches and brakes for continuously shifting in a high range, a mid range, a low range, and a reverse range. Therefore, it is complicated and difficult to control, and the number of parts is increased.

    Therefore, in order to solve the above problems, the present invention reduces the number of parts while using a belt type CVT or toroidal type transmission and a planetary gear speed reducer, and can reduce the cost, compactness and complicated control. A step transmission can be provided.

Means for solving the problem

  The continuously variable transmission of the present invention for solving the above-described problems is obtained by connecting and integrating sun gears 1a and 2a on the same input shaft 1 in the schematic cross-sectional view of FIG. 1, and a planetary gear 1b around the sun gear 1a, An internal gear 1c and a carrier 1d are arranged, and a planetary gear 2b, an internal gear 2c and a carrier 2d are arranged around the sun gear 2a, and the internal gears 1c and 2c are connected and rotated together. The carrier 1d of the planetary gear mechanism rotates the intermediate gear 6, the gear 5, and the rotating shaft 9 for rotating in the same direction as the input shaft 1 by the rotation of the gear 7 fixed on the input shaft 1 that transmits the input rotation. The rotation is transmitted to the driven pulley 8 of the belt type CVT through the belt 11, and the carrier 1 d is rotated by rotating the driving pulley 10 of the CVT coupled and integrated with the carrier 1 d through the belt 11.

    If the carrier 1d is fixed, the planetary gear reducer has the sun gears 1a and 2a connected and integrated on the input shaft 1, and the internal gears 1c and 2c are also connected and integrated. When rotating around, the internal gears 1c and 2c rotate counterclockwise, and the planetary gear 2b revolves around the sun gear 2a while rotating around its own axis. That is, the carrier 2d rotates due to the speed difference between the internal gear 2c that rotates counterclockwise and the planetary gear 2b that revolves around the sun gear 2a. If the number of teeth of the sun gears 1a and 2a of the planetary gear reducer is Z1a and Z2a, the number of teeth of the planetary gears 1b and 2b is Z1b and Z2b, and the number of teeth of the internal gears 1c and 2c is Z1c and Z2c, the reduction ratio is It can be expressed as

  Here, when a rotational force is applied to the carrier 1d via the CVT, the carrier 2d rotates at a combined reduction ratio of the rotation of the carrier 1d and the planetary gear reducer. In other words, the vehicle rotates at a reduction ratio N expressed by Equation 2.

  X in Equation 2 is the reduction ratio of the carrier 1d. The reduction ratio of the carrier 1d is n1 as the gear ratio (reduction ratio) between the gear 7 and the gear 5 fixed to the input shaft 1, and the gear 5 and the rotary shaft 9 X can be shifted from 1 / (n1 × n2) to n2 / n1, where n2 is the transmission ratio of the CVT connected through the. As can be seen from this, the variable speed region can be increased by changing the CVT via the gears 5, 6, 7 and the rotating shaft 9 rather than the CVT alone.

  The carrier 2d (output) is decelerating when the numerator in the calculation formula 2 is positive and 1>, and when n2 / n1 = 1, the input shaft 1 and the carrier 2d rotate at a constant speed and n2 / n1> 1. In this case, the speed is increased. When the numerator is 0, the carrier 2d does not rotate even if the neutral point, that is, the input shaft 1 and the carrier 1d are rotating. If the numerator is negative, it will slow down while reversing.

  That is, decelerating while reversing allows the vehicle to move backward without providing a back gear.

  In this transmission, the planetary gear speed reducer is a main mechanism for power transmission, and the CVT is a control mechanism for shifting continuously. By changing the combination of the number of teeth Z1a, Z2a, Z1c, Z2c in Equation 2, various transmission characteristics can be obtained, and the selection range of the carrier 1d is determined by selecting X in Equation 2.

  As shown above, the power transmission is mainly performed by the planetary gear reducer, but the energy branched by the gear 7 is also returned to the planetary gear reducer through the gears 6 and 5, the rotating shaft 9, the CVT, and the carrier 1d. The overall efficiency of the step transmission can be further improved.

    Embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic sectional view of a continuously variable transmission according to the present invention. FIG. 2 is a skeleton diagram of FIG. Skeleton In FIG. 2, sun gears 1a and 2a connected and integrated on the same input shaft 1 are arranged, planetary gears 1b and 2b are arranged around the sun gears, and internal gears 1c and 2c are arranged around the planetary gears. The internal gears 1c and 2c are connected and integrated to be rotatable.

    The power for shifting is transmitted to the carrier 1d fixed to the CVT via the gear 7, the intermediate gear 6, the gear 5, the rotating shaft 9, and the CVT fixed on the input shaft, and the CVT groove width is variable and the carrier 2 output The speed of the shaft 2 can be changed.

    FIG. 3 is a graph when the gear is selected so that the neutral point is within the shift selection range of the carrier 1d in FIG.

    In FIG. 3, when N = 1, that is, the CVT is varied and the speed of the carrier 1d is varied so that n2 / n1 = X = 1, the input shaft 1 and the output shaft 2 become constant speed. If the speed of the carrier 1d is decreased from that point, the reduction ratio of the carrier 2d increases, and the carrier 2d does not rotate when the numerator becomes 0 in Equation 2. When the speed of the carrier 1d is further decreased, the carrier 2d is reversed as shown in FIG. When X> 1, the speed of the carrier 2d is increased, that is, the speed of the output shaft 2 becomes faster than the rotation of the input shaft 1. Thus, the constant speed, deceleration, reverse, and acceleration required for the vehicle can be configured with a reduced number of parts.

    FIG. 4 is a schematic cross-sectional view of a continuously variable transmission having a clutch CL on the gear 7 on the input shaft 1 and a brake Br on the drive side of the CVT.

    In FIG. 5, when the gear selection range of the carrier 1d in which the reduction ratio of the gears 5 and 7 and the transmission ratio of the CVT are selected so as to become the neutral point when the driven pulley 8 of the CVT becomes the minimum diameter, When the driven pulley 8 reaches the minimum diameter, the planetary gear reducer rotates in the same manner as the neutral point, that is, neutral, in the vehicle, but the carrier 2d and the output shaft 2 do not rotate. However, the difference from the neutral of the vehicle is that the planetary gear reducer stops while rotating and is braked with a large reduction ratio.

    When the clutch CL provided on the gear 7 on the input shaft 1 in FIG. 4 is released at the neutral point and is fixed with the brake Br provided on the drive side of the CVT, the carrier 1d is fixed. Therefore, the carrier 1d is fixed in the graph of FIG. 5, and the carrier 2d is inverted at the reduction ratio calculated by the equation (1).

    FIG. 6 shows a case where the shift selection range of the carrier 1d is set in the range having the clutch CL and the brake Br in FIG. 4 but not using the neutral point, and the clutch CL is released while the speed of the carrier 2d is reduced. Even if a driving force is applied to the planetary gear 1, the planetary gear speed reducer simply rotates idle and torque is not transmitted. This is the same as the neutral state for vehicles. If the CVT is fixed with the brake Br in FIG. 4 in this state, the carrier 1d is fixed, so that the carrier 1d is fixed in the graph of FIG. It becomes the same as the state where the back gear for the vehicle is put. The brake Br may be provided at a position where the rotating shaft 9, CVT, or carrier 1d is directly fixed.

The invention's effect

    As described above, the continuously variable transmission of the present invention selects the number of teeth of the sun gears 1a and 2a, the planetary gears 1b and 2b, and the internal teeth 1c and 2c so that the characteristics shown in FIG. When the continuously variable transmission of the present invention is used, the CVT is gradually increased from the neutral point where the output shaft 2 does not rotate even when the input shaft 1 rotates, and the engine starts. Can do. Then, as shown in the skeleton diagram of FIG. 2 and the graph of FIG. 3, neutral point, deceleration, constant speed, speed increase, and reverse functions can be provided only by CVT shift without clutch and back gear. .

    Further, since the structure is simple, the number of parts can be reduced and the entire apparatus can be made compact.

    In FIG. 2, the continuously variable transmission device is a planetary gear reducer that is the main for power transmission, and the CVT is a control mechanism for shifting without permission. Therefore, the CVT can be miniaturized, and the characteristics of the planetary gear reducer that can output a large torque can be utilized.

    Since the CVT is rotated at a reduced speed by the gears 7, 6 and 5, mechanical stress due to the high speed rotation of the CVT can be reduced, and the speed change region of the carrier 1d is increased by the reduction of the gears 7, 6 and 5. be able to.

    As shown in FIG. 4, the clutch 7 is provided on the gear 7, the brake 1 is provided on the driving side of the CVT or the carrier 1 d and the carrier 1 d is fixed, so that the output shaft 2 can easily reverse and reverse. Characteristics as shown in the graph of FIG. 6 can be selected.

    The transmission of power is mainly a planetary gear reducer, but the energy branched by the gear 7 for shifting is also returned to the planetary gear reducer through the gears 6 and 5, the rotary shaft 9, the CVT, and the carrier 1d. The efficiency of the entire apparatus can be improved.

    1 is a schematic cross-sectional view of a continuously variable transmission according to the present invention.     FIG. 2 is a skeleton diagram of FIG. 1.     It is an example of the relationship graph of the gear ratio of the carrier 1d, and an operation mode.     It is a cross-sectional schematic diagram of a continuously variable transmission provided with a clutch CL and a brake Br in the present invention.     It is an example of the relationship graph of the gear ratio of the carrier 1d of FIG. 4, and an operation mode.     Similarly, it is an example of a relationship graph between the gear ratio of the carrier 1d and the operation mode in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Input shaft 2 ... Output shaft 3 ... Planetary gear reducer 4 ... Case 5 ... Gear 6 ... Intermediate gear 7 ... Gear 8 ... Drive side pulley of belt type CVT 9 ... Rotating shaft 10 ... Drive side pulley of belt type CVT 11 ... CVT belt 12, 13 ... Carrier pin 1a, 2a ... Sun gear 1b, 2b ... Planetary gear 1c, 2c ... Internal teeth 1d, 2d ... Carrier CVT ... Belt type CVT
Br ... brake

Claims (4)

    Gears on the input shaft 1 that transmit the rotation of the carrier 1d of the planetary gear mechanism in which the sun gears 1a and 2a are connected and integrated on the same input shaft 1 and the internal gears 1c and 2c are also connected and rotated. 7 and 6, 5 and CVT which rotates via the rotating shaft 9, and continuously variable transmission which takes out the continuously variable transmission output from the carrier 2d.     In Claim 1, the gear 7 on the input shaft 1 that transmits the rotation to the CVT is provided with a clutch CL, and the brake Br on the rotational force transmission circuit from the rotary shaft 9 that connects the CVT and the gear 5 to the carrier 1d on the drive side of the CVT. A continuously variable transmission including a clutch CL and a brake Br for releasing the clutch CL to cut off the rotational force from the input shaft 1 and stopping the rotation of the rotary shaft 9 or CVT and the carrier 1d by the brake Br.     The gears 7 and 6, 5 and CVT of claim 1 are arranged in parallel, the gears 5 and CVT are connected by the rotary shaft 9, and the gear 6 of the intermediate gear that matches the rotation direction of the input shaft 1 and the CVT is arranged. The gear 5 is a continuously variable transmission in which the speed change region of the carrier 1d is increased by decelerating the gear 5 with a larger number of teeth than the gear 7.     A continuously variable transmission in which a toroidal continuously variable transmission is arranged instead of the belt type CVT.

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