JP2013217434A - Continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem that an internal combustion engine is common as a driving force of an automobile or the like, however, it is expected that an automobile using an electric motor also prevails from now on, therefore, in either driving force, it has a tendency to improve fuel consumption and to achieve energy-saving of power consumption, accordingly, in order to attain them, there is one method of maintaining the rotational frequency of the driving force at a level as constant as possible, for example, if the frequency of opening/closing an accelerator is increased, the fuel consumption of the internal combustion engine deteriorates while the power consumption at the start of the electric motor is larger than the power consumption during normal traveling, thus, even if it is an electric vehicle, a transmission is needed for a medium-sized vehicle and a large-sized vehicle other than a small-sized vehicle.SOLUTION: A negative feedback continuously variable transmission is configured as follows. A transmission part in which gears, a sprocket, a roller chain, a pulley, and a belt are freely combined with each other is provided between a primary differential, becoming the input side and including a synchronous torque transmission mechanism, and a secondary differential becoming the output side. The synchronous torque transmission mechanism and the transmission part are configured to work as a negative feedback mechanism such that an output torque load is fed back to always maintain input torque at a constant level.

Description

The present invention relates to a negative feedback continuously variable transmission that includes a differential device and a synchronous torque transmission mechanism and that is not capable of torque.

The continuously variable transmission of Japanese Patent No. 4039366 is a steel belt formed by superposing several sheets of tough special steel, and a metal frame is tightly fitted, and the driving force from the pulley is adjacent. The steel belt acts as a subordinate guide.

In the continuously variable transmission of Japanese Patent No. 4875732, a planetary gear type auxiliary transmission is installed on a secondary pulley on the output side. This sub-transmission has a two-speed forward shifting function and a forward / reverse switching function. In the conventional steel belt type continuously variable transmission, it is installed between the primary pulley on the input side and the clutch mechanism for power interruption. It also serves as a planetary gear for forward / reverse switching.

The continuously variable transmission of Japanese Patent No. 4145707 has better transmission efficiency at the low speed / high speed gear ratio than the steel belt type, and the pulley winding radius can be reduced, so the pulley diameter is reduced and the same physique Can increase the gear ratio. However, since the pin and the pulley are in point contact to transmit power, the noise tends to be larger than that of the steel belt type that contacts the surface.

The toroidal continuously variable transmission disclosed in Japanese Patent No. 4035317 is a form in which a friction drive is highly developed. Two disks on the input side and the output side are arranged in parallel, and a plurality of frame-type power rollers are sandwiched between them with a strong force. When the inclination angle of the power roller is changed, the ratio of the rotational speeds of the two disks is changed accordingly, and a variable gear ratio is obtained.

The continuously variable transmission of Japanese Patent No. 4686899 performs power amplification of the engine by electric control of a general mechanical reduction mechanism, a generator and a motor, and the speed change is realized by only one set of planetary gears. The rotation speed of the generator, engine, and motor is represented by a straight line on the nomograph, the engine crankshaft is connected to the planetary carrier, the generator is connected to the sun gear, and the motor and wheels are mechanically connected directly to the output. Connected to the gear. For this reason, the motor always rotates when the wheel is rotating, and since it is directly connected to the wheel, a motor with a high torque specification is inevitably required to ensure the driving force at the start.

The continuously variable transmission disclosed in Japanese Patent No. 4762588 is a system in which the hydraulic pressure generated by driving a hydraulic pump with an engine is converted again into rotational force by a hydraulic motor, and the operating stroke of the piston of the hydraulic pump is in contact with the piston. By changing the angle of the plate, the flow rate of hydraulic oil is continuously increased or decreased to adjust the speed.

Unlike the hydrostatic continuously variable transmission in which all of the driving power is temporarily converted into hydraulic pressure, the continuously variable transmission of Japanese Patent No. 401241 is configured by combining a planetary gear and a hydrostatic continuously variable transmission. Yes. For example, the reduction gear ratio can be controlled freely by using the sun gear as the input shaft and the planetary gear as the output shaft, and controlling the rotation of the ring gear continuously with a hydrostatic continuously variable transmission. The transmission efficiency of the entire transmission is improved while taking advantage of the continuously variable transmission.

The continuously variable transmission of Japanese Patent No. 3658663 is a continuously variable automatic transmission that includes a slidable clutch and a planetary gear. A torque converter and coupling are provided, and in addition to the clutch function, the torque also serves as a power storage function. Since no hydraulic mechanism, brake band, etc. are required, the number of parts is extremely small, and the gear ratio changes according to the vehicle speed and the engine speed. Further, since it is used only in a state where the torque converter, pump and turbine have a high rotation ratio, it does not become a stalled state and has good fuel efficiency.

The continuously variable transmission of Japanese Patent Publication No. 3689020 is a transmission that incorporates a planetary gear mechanism and controls the turning movement to interfere with each other to change the gear ratio.

Japanese Patent No. 4039366 Japanese Patent No. 4875732 Japanese Patent No. 4145707 Japanese Patent No. 4035317 Japanese Patent No. 4686899 Japanese Patent No. 4762588 Japanese Patent No. 4012401 Japanese Patent No. 3658663 Japanese Patent No. 3689020 Japanese Patent No. 4012940

An internal combustion engine is generally used as a driving force for automobiles, but automobiles using electric motors are expected to become popular in the future. In any driving force, there is a tendency to improve fuel consumption and save power consumption. For this purpose, one method is to keep the rotational speed of the driving force as constant as possible. For example, if the frequency of opening and closing the accelerator is increased for an internal combustion engine, the fuel efficiency will deteriorate, and the electric motor will start to consume more power than the normal driving power.・ Transmissions are required for large vehicles.
In general, an inertial force due to the weight of the vehicle acts at the start from the stop state to the normal running, and the torque load applied to the drive shaft increases. Therefore, a transmission that keeps the rotational speed of the driving force as constant as possible is desired, but it is considered that the above problem can be solved if the speed is reduced according to the torque load applied to the drive shaft. Therefore, by providing a transmission that can automatically change the gear ratio continuously in accordance with the output torque load, the rotational speed on the input side is kept constant, and the gear ratio is kept at an ideal ratio until steady running. Provide shifting.

A transmission unit that freely combines gears, sprockets, roller chains, pulleys, belts, etc. is provided between the primary differential device equipped with a synchronous torque transmission mechanism on the input side and the secondary differential device on the output side, A negative feedback continuously variable transmission in which the synchronous torque transmission mechanism and the transmission unit function as a negative feedback mechanism, and the output torque load is fed back to keep the input torque constant.

The synchronous torque transmission mechanism is a mechanism unique to the present application. A cam ball is arranged between a drive cam having a shaft and a driven cam, and the ball holding portion formed on the drive cam allows the cam ball to move within a certain range. In addition, a groove in which the sine wave is synthesized on the circumferential line is formed in the driven cam, and when the drive cam rotates, the cam ball moves in the groove of the driven cam according to the torque load of the driven cam, and the torque load of the driven cam decreases. The driven cam begins to rotate as it goes.
The function that the drive shaft transmits torque according to the torque load of the driven shaft is the same as that of the torque converter. In this sense, the pump impeller can be converted into a drive cam, the turbine runner can be converted into a driven cam, and the fluid can be converted into a cam ball. When the ball stops moving in the cam groove, the drive cam and the driven cam are synchronized and the rotation speed is the same.

The differential is a known technology, and a pair of side gears on the same shaft mesh with each other through a pinion gear supported freely in a differential case and the pinion gear to form or attach a ring gear to the differential case, and torque to the ring gear. The torque is distributed to the both side gears.

In the case of a planetary gear mechanism, the differential pinion gear is a planetary gear (planetary gear), the differential case is a carrier (planetary carrier), one side gear is a sun gear (sun gear), and the other is on the same axis as the sun gear. By replacing it with the second sun gear or the outer gear (internal gear) of different diameter, various types of differential gears are possible, and the purpose of this differential gear is to distribute the torque to the left and right wheels of the car. Therefore, it is possible to reduce the size by utilizing the diameter ratio of the sun gear and the outer gear.

The planetary gear mechanism is a known technique, and in particular, Japanese Patent No. 4012940 discloses systematic classification and explanation regarding the planetary gear mechanism.

By providing a speed changer that freely combines gears, sprockets, roller chains, pulleys, belts, etc. between the two differential gears, you can freely adjust the torque, rotation speed, and gear ratio. The transmission can be designed, and the synchronous torque transmission mechanism is configured with a small number of parts and can transmit a large torque even if it is small.

Schematic of synchronous torque transmission mechanism of Examples 1 to 4 Skeleton diagram of continuously variable transmission of embodiment 1 Skeleton diagram of continuously variable transmission of embodiment 4

The continuously variable transmission according to the first embodiment includes a primary differential device 10, a secondary differential device 20, a first transmission unit 30, a second transmission unit 40, and a synchronous torque transmission mechanism 1. Torque is input to the ring gear 12, the torque is distributed between the first side gear 14a and the second side gear 14b of the differential, and the first transmission unit and the second transmission unit change the rotation ratio, respectively. Torque is transmitted to the first side gear 24 a and the second side gear 24 b of the differential device, and the torque synthesized by the differential device is output from the ring gear 22.

The primary differential device 10 is composed of a synchronous torque transmission mechanism 1, a first side gear 14a, a second side gear 14b and a pinion gear 13, and a ring gear 12 formed on the outer periphery of the holder. The holding body rotates simultaneously with the rotation of the ring gear.
Between the side gears 14a, 14b having the same axis as the holding body shaft, the pinion gear having an axis perpendicular to the rotation axis of the holding body is rotatably supported by the holding body, and the pinion gear is supported by the side gear. 14a and 14b are intervening and meshing.
If the torque loads of the side gears 14a and 14b are the same as the ring gear rotates, the pinion gear does not rotate according to the principle of the differential gear, and the side gears 14a and 14b transmit torque at the same rotational speed.
If the torque loads of the side gears 14a and 14b are not the same, the pinion gear transmits torque at a high rotation ratio to the side gear with a small torque load according to the principle of the differential.

The synchronous torque transmission mechanism 1 includes a drive cam 2, a driven cam 5, and a cam ball 8. The drive cam is formed with six long hole holding portions 4 on the radiation, and the cam ball is held by the holding portion. When the drive cam rotates, the cam ball can freely move on each radiation in the holding portion.
The follower cam is formed with a guide ball guide groove 7 in which a sine wave is synthesized on a circumferential line, and the cam ball can freely freely move in the groove as needed.
When the drive cam rotates, the cam ball moves in an orbital angle around the rotation axis, but if necessary, the holding portion can move linearly, so the cam ball is a combination of two movements and moves in a sine wave on the circumference. However, it is a condition that the guide groove is within an allowable range of the combined motion.
According to the law of conservation of angular momentum, the cam ball tries to make a circular motion (conformal motion), and the cam ball tries to rotate the driven cam rather than moving in the groove by the action of the law. When the torque load of the driven cam is reduced by the action of the law, the cam ball gradually shortens the moving distance in the guide groove, and the driven cam starts to rotate.
When the driven cam, which has started rotating, stops moving in the guide groove, the driving cam and the driven cam are synchronized in angular motion and have the same rotational speed.

The secondary differential device includes a holding body 21 in which a first side gear 24a, a second side gear 24b, and a pinion gear 23 are provided, and a ring gear 22 formed on the outer periphery of the holding body, and the differential device that is an output gear. According to the torque load of the ring gear 22, the load is distributed to the side gears 24 a and 24 b, and the ring gear outputs again at the combined rotational speed by the action of the negative feedback mechanism.

The first transmission unit 30 includes a pinion gear 31 and a spa gear 32. The pinion gear is fixed to the shaft of the first side gear 14a of the primary differential device 10, and the spa gear is mounted on the shaft of the first side gear 24a of the secondary differential device. Is fixed, and a rotation ratio m of the transmission unit is determined by a combination of the diameters of the pinion gear and the spa gear.

The second transmission unit 40 includes a pinion gear 42 and a spa gear 41. The pinion gear is fixed to the shaft of the second side gear 14b of the primary differential 10, and the spa gear is fixed to the shaft of the second side gear 24b of the secondary differential. Is fixed, and the rotation ratio n of the transmission unit is determined by the combination of the diameters of the pinion gear and the spa gear.

The first internal torque load is a factor of the negative feedback mechanism. When the torque input from the ring gear 12 of the primary differential device 10 is transmitted to the ring gear 22 of the secondary differential device via the first transmission unit 30, the first internal torque load is transmitted. The synchronous torque transmission mechanism 1 includes a gear ratio of the first transmission unit 30, a gear ratio of the second transmission unit 40, an input torque to the primary differential device, and an output torque load from the secondary differential device. The value of the first internal torque load varies as a result of adjustment.

The second internal torque load is a factor of the negative feedback mechanism. When the torque input from the ring gear 12 of the primary differential device 10 is transmitted to the ring gear 22 of the secondary differential device via the second transmission 40, the second internal torque load is transmitted. The synchronous torque transmission mechanism 1 includes a gear ratio of the first transmission unit 30, a gear ratio of the second transmission unit 40, an input torque to the primary differential device, and an output torque load from the secondary differential device. The value of the first internal torque load varies as a result of adjustment.

Next, the relationship of the number of rotations in the device up to the output when torque is input to the continuously variable transmission of the present application is shown. When x is the input of the number of rotations to the ring gear 12 of the primary differential, If the output of the number of rotations from the ring gear 22 of the differential gear is y, the number of rotations of the first transmission unit 30 is m, and the number of rotations of the second transmission unit 40 is n, y = f (x). Become a relationship.

When m <n, the value is between m ≦ y ≦ (m + n) / 2 depending on the output torque load of the secondary differential. Here, the input torque to the primary differential device tries to rotate the first transmission unit 30 having a small internal torque load at m based on the relationship between the action of the moment of inertia and the gear ratio of m <n at the time of starting. At this time, n does not rotate. The rotation of m rotates y, and the value is y = m. Next, the output torque load gradually decreases with the rotation of y. As the output torque load decreases, the internal torque loads of the first transmission unit 30 and the second transmission unit 40 also decrease. Here, from the relationship of m <n as an initial setting, if the first internal torque load is t1, and the second internal torque load is t2, the relationship is t1 <t2.
Further, when the output load becomes zero, the side gears 14a and 14b of the differential device start to move at the same rotation speed by the adjustment of the synchronous torque transmission mechanism incorporated in the primary differential device. At this time, the output torque is y = (m + n) / 2.

Regarding the setting of the gear ratio, in order to change the input rotation speed to 1 and the output rotation in the range of 1 to 1/5, x is set to x / 5 when the value of y is m and becomes x when (m + n) / 2. The gear ratio may be set as follows. Accordingly, the gear ratio may be set so that m = x / 5 and x = (m + n) / 2, and m = x / 5 and n = 9x / 5.

The continuously variable transmission of the second embodiment is a continuously variable transmission having the same structure as that of the first embodiment except that the transmission portion is composed of a sprocket and a roller chain, and the functions and structures of the sprocket and the roller chain are known techniques. The description is omitted.

The continuously variable transmission of the third embodiment is a continuously variable transmission having the same structure as that of the first embodiment except that the transmission portion is constituted by a pulley and a belt. The functions and structures of the pulley and the belt are well-known techniques. Is omitted.

The continuously variable transmission of the fourth embodiment includes a primary planetary gear mechanism 50, a secondary planetary gear mechanism 60, a transmission unit 70, and a synchronous torque transmission mechanism 1, and inputs torque to the carrier 52 of the primary planetary gear mechanism. The planetary gear 53 of the planetary gear mechanism distributes torque to the sun gear 51 and the outer gear 54.
The outer gear 54 and the outer gear 64 of the secondary planetary gear mechanism are directly connected, and the synchronous torque transmission mechanism 1 is connected between the sun gear 51 and the sun gear 61 of the secondary planetary gear mechanism. The sun gear 51 is connected to the transmission gear 74 of the transmission unit 70. The planetary gear 43 that transmits the rotation and is fixed on the same axis of the transmission gear is rotatably supported by the carrier 72 and shifts according to the output torque load.

The primary planetary gear mechanism includes a synchronous torque transmission mechanism 1, a sun gear 51, an outer gear 54, a first carrier 52, and a planetary gear 53, and the planetary gear is rotatably supported on the carrier, and the planetary gear is connected to the sun gear and the planetary gear. It intervenes and meshes between the outer gears.
The torque of the carrier shaft distributes the torque to the sun gear and the outer gear according to the output torque load of the second carrier of the secondary planetary gear mechanism in relation to the difference in torque load between the sun gear and the outer gear and the planetary gear. .

The secondary planetary gear mechanism is composed of a sun gear 61, an outer gear 64, a carrier 62, and a planetary gear 63, and distributes the load to the sun gear and the outer gear according to the torque load of the carrier that is an output gear. As a result, the ring gear synthesizes and outputs the rotational speed.

Automobile continuously variable transmission.

When industrial machine tools, especially machines that use drills, are likely to cause drill breakage or deformation of the workpiece due to heat, the output speed will be reduced according to the output torque load within the range of performance inherent to the transmission. Acts as follows.

By installing it in the sewing machine or between the motors, the speed at the time of starting is reduced, and the resistance of the needle automatically responds to fluctuations in the thickness and hardness of the sewing fabric during normal rotation. Needle breakage can be reduced by reducing the speed.

DESCRIPTION OF SYMBOLS 1 Synchronous torque transmission mechanism 2 Drive cam 3 Drive cam shaft 4 Cam ball holding part 5 Drive cam 6 Drive cam shaft 7 Guide groove 8 Cam ball 10 Primary differential 11 Holding body 12 Ring gear 13 Pinion gear 14a First side gear 14b Second side gear 20 Secondary differential device 21 Holding body 22 Ring gear 23 Pinion gear 24a First side gear 24b Second side gear 30 First transmission unit 31 Pinion gear 32 Spa gear 40 Second transmission unit 41 Spa gear 42 Pinion gear 50 Primary planetary gear mechanism 51 Sun gear 52 Carrier 53 Planetary gear 54 Outer gear 60 Secondary planetary gear mechanism 61 Sun gear 62 Carrier 63 Planetary gear 64 Outer gear 70 Transmission unit 71 Sun gear 72 Carrier 73 Planetary gear 74 Transmission gear

Claims (3)

It consists of a primary differential device (primary planetary gear mechanism), a secondary differential device (secondary planetary gear mechanism), a synchronous torque transmission mechanism, and a transmission unit. When torque is input to the primary differential device, the differential device The torque is divided into two parts, the rotational speed is changed from m to n by the transmission unit, the torque is transmitted to the secondary differential, the torque is synthesized by the differential, and the magnitude of the output torque load A continuously variable transmission characterized in that the speed ratio is automatically and continuously variable. Provide a transmission that freely combines gears, sprockets, roller chains, pulleys, belts, etc. between the primary differential equipped with a synchronous torque transmission mechanism on the input side and the secondary differential on the output side. 2. The continuously variable transmission according to claim 1, wherein the synchronous torque transmission mechanism and the transmission unit function as a negative feedback mechanism, and an output torque load is fed back to keep the input torque constant. The synchronous torque transmission mechanism includes a drive cam, a driven cam, and a cam ball. The drive cam holds the cam ball, and the driven cam is formed with a guide groove that combines a sine wave on a circumferential line. When is rotated, the cam ball periodically moves in the guide groove.
As the torque load becomes smaller, the distance that the cam ball moves in the groove becomes shorter, the driven cam starts to rotate, and when the cam ball stops in the guide groove, the drive cam and the driven cam undergo angular motion. 2. A synchronous torque transmission mechanism as a component of a continuously variable transmission according to claim 1, wherein the synchronous torque transmission is synchronized and has the same rotational speed.

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