WO2004059190A1

WO2004059190A1 - Machinetype transmission for a car

Info

Publication number: WO2004059190A1
Application number: PCT/KR2003/002940
Authority: WO
Inventors: Seok-Bong Nam
Original assignee: Seok-Bong Nam
Priority date: 2002-12-31
Filing date: 2003-12-31
Publication date: 2004-07-15
Also published as: KR20040062213A; AU2003289594A1

Abstract

The present invention is to provide a continuously variable mechanical transmission system for a car capable of silent transmission through mitigation of noise, vibration and transmission shock generated upon transmission operation and having an excellent transmission capability, in which a driver gear in an idle state is engaged with an inlet gear that is formed in multi-step on a circumferential surface of a cone by stepping on a launching pedal, thereby realizing the transmission so that revolutions of an outlet gear increases by the driver gear moving toward a gear at a large diameter portion as revolutions of the inlet gear increases while revolutions of the outlet gear decreases by the driver gear moving toward a gear at a small diameter portion slowly. If a backward lever is operated, a gear in a propeller system becomes an idle state through disengagement from the inlet gear, and only the backward gear is engaged with the inlet and the outlet gears such that the backward is conducted by an idler function of a propeller gear.

Description

ACHINETYPE TRANSMISSION FOR A CAR

TECHNICAL FIELD

The present invention relates to a continuously variable machinetype transmission for a car which capable of a silent transmission operation through significant mitigation of noise, vibration and transmission shock generated upon transmission and which has excellent transmission capability.

BACKGROUND ART

A continuously variable transmission system for an automobile is a transmission system capable of transmission without clutch and transmission lever operations by a driver. The continuously variable transmission system is different from an automatic transmission system in that a variator of continuously variable transmission makes transmission up to an infinite level while continuously transient between a maximum transmission gear ratio and a minimum transmission gear ratio according to a given transmission pattern in a transmission gear ratio which is capable of transmission, unlike the automatic transmission system having a speed ratio confined to limited speed levels such as a level 3, a level 4 and a level 5.

There are toroidal and mechanic-hydraulic types of continuously variable transmissions. The toroidal type of continuously variable transmission is a transmission delivering a force of an input shaft to an output shaft using a friction force obtained when transmission variator enables an input disc and an output disc in which a groove is formed on a circular plane thereof and a plurality of power rollers positioned between the input disc and the output disc to be contiguous. The continuously variable transmission obtains a continuously variable transmission effect by changing a rotation effective radius between them. The continuously variable transmission has a relatively simple structure and less vibration and noise and accordingly is very silent. On the other hand, because there is a need for high contact pressure to deliver the power between a metal roller and a lace, the accuracy of a contact face between them is high. Further, because the power is delivered by a physical contact between an input disc, an output disc and the power roller, it is necessary to use a material with excellent rigidity and duration. There is also a shortcoming in that cost is added due to the use of special lubricating oil which is tolerable against limit temperature and pressure needed to accomplish the continuously variable transmission by delivering the power using the force resultant from a traction force, which increases manufacturing cost.

Meanwhile, a mechanical-hydraulic type of continuously variable transmission system is a transmission and power-delivering apparatus for delivering an input from an engine, an electric motor, or the like to a hydraulic type of power-delivering apparatus's variator and a mechanical type of power-delivering apparatus without using an oscillating apparatus, and for outputting it by connecting a load portion to a hydraulic pump-motor assembly or a planetary gear system. It advantageously has acceleration capability, fuel saving, small transmission shock, and convenience of driving operation. However, the efficiency of the hydraulic type variator is only 85% and a noise problem still remains.

DISCLOSURE OF THE INVENTION

The present invention is to provide a mechanical type of continuously variable transmission for an automobile which is capable of enhancing transmission silence by minimizing noise, vibration, and transmission shock generated upon transmission and which has excellent transmission efficiency.

This object can be achieved by an automotive transmission of the present invention having such a configuration that when a launching petal is stepped on, an output side gear in a rest state engages with a lowest gear of a cone type input gear having transmission gears for respective rotational speeds formed for respective steps on a circumferential surface thereof to initiate the output, increasing transmission in which a side gear moves sequentially from a lower step gear to a higher step gear and reducing transmission in which the side gear moves progressively from the higher step gear to the lower step gear are performed according to high speed rotation of the input gear, and when a reverse button or a reverse lever is operated, a side gear of an output bridge gear system and a side gear of an output gear system return together to a neutral position and the side gear of the reverse gear system engages with an idler gear of the output gear system in sequence to output reverse power.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a perspective view of a mechanical type of continuously variable transmission, viewed from an output bridge device, according to the present invention;

Fig. 2 is a side view of an input gear viewed from a lowest gear side;

Fig. 3 is a sectional view showing a state where a side gear is disposed on a shaft; Fig. 4 is a perspective view of the continuously variable transmission viewed from a reverse gear system;

Fig. 5 is a schematic gear displacement view of a reverse gear system; Fig. 6 is an exploded view of a side gear disjunction device which excludes a screw bar driving means; Fig. 7 is a view illustrating a case where a leading side gear is moved by a slider;

Fig. 8 is a view illustrating a case where a following side gear is moved by a leading side gear to form a circular gear form;

Fig. 9 is an exploded view of a slider activity width expanding means added to a side gear disjunction device for an output gear system;

Fig. 10 is a sectional view of an assembly of Fig. 9; and Fig. 11 is a view illustrating a situation where the power from a screw bar driving device is supplied to a pinion.

BEST MODE FOR CARRYING OUT THE INVENTION

In Fig. 1 , a mechanical type of continuously variable transmission of the present invention is composed of an input gear system 10, an output bridge device 20, an output gear system 30, a reverse gear system 40, a reverse bridge device 50, a side gear disjunction device 60a for the output bridge device, a side gear disjunction device 70 for the output gear system, and a side gear disjunction device 60b for the reverse bridge device.

The input gear system 10 is disposed on an input shaft S1 so that an input gear 11 is used as a transmission gear and a lowest gear 11a of the input gear 11 is placed at an output side of the input gear system, wherein a gear for transmission is formed in a multi-step at a circumferential surface of a corn. In the input gear 11 , middle gears 11b to 11n-1 are formed for respective speeds between the lowest gear 11a at a small diameter portion and a highest gear 11n. The gears 11a to 11 n of the respective steps are the same as a pitch in a tooth type. This allows the activity of a side gear for output, wherein the output side gear is adapted to be selectively connected to the gears 11a to 11 n for respective steps according to the rotational speed of the input gear 11.

In Fig. 2, a straight teeth train 12 is found when the gears 11a to 11 n for respective speeds in the input gear 11 are viewed from the lowest step gear. The straight teeth train 12 serves as a passage or a guide for shifting the side gear of the output gear system 30 to the gears for respective speeds. If there is no straight teeth train 12, shifting output by the side gear is impossible. It is effective in a shifting operation to form such a straight teeth train 12 at least at a place where its circumference is halved. The straight teeth train 12 can be attained by ideally designing the taper of the corn, the number of saw teeth of gear trains 11a to 11 n, and the pitch.

Returning to Fig. 1 , a bridge shaft S2, which is disposed corresponding to the gradient of the input gear 11 , is present beside the input shaft S1. An output bridge device 20 is disposed on the bridge shaft. The output bridge device 20 is composed of two side gears 21 and 22 disposed at a front end portion of the bridge shaft S2 so that divided faces obtained by halving the circumference face to each other but maintain a gap on the order of its thickness, and a bridge gear 23 disposed at a rear end portion of the bridge shaft S2. The bridge shaft S2 allows a power to be delivered to the output shaft S3 via the side gears 21 and 22 at any time upon launching as the bridge gear 23 always engages with the lowest gear 11a of the input gear 11.

In Fig. 3, grooves 24 on which protrusions of side gears 21 and 22 ride in an axial direction are formed at places on the bridge shaft S2 where the circumference is halved. Protrusions 25 are formed at both sides of the divided faces in the side gears 21 and 22 to block the side gears 21 and 22 from taking off the grooves 24 in a center direction of the bridge shaft S2 by engaging with the grooves 24. Further, a push bar groove 26 is formed at a front face of the side gear 21 and a rear face of the side gear 22 to efficiently deliver a force for moving the side gears 21 and 22 as the end of the push bar 66a or 66b dependent on the side gear disjunction device 60a is hanged on the push bar groove and to prevent the side gears 21 and 22 from deviating from a control of the side gear disjunction device 60a even upon high speed rotation. The push bar groove 26 is formed at an intermediate position between the side gears 21 and 22 so that control is twice provided by the push bar 66a or 66b per one rotation, thereby increasing reliability in operation.

Returning to Fig. 1 , the leading side gear 21 remains at a neutral state and then advances by means of a side gear disjunction device 60a and, upon engaging with an idler gear 31 of the output shaft S3, engages the idler gear smoothly to allows power bridge to be attained, in which the idler gear naturally had a heavy load because of its stationary state. The following side gear 22 advances by means of the side gear disjunction device 60a to join together the leading side gear 21 so that its complete circular gear form smoothly performs a power bridge operation, as soon as the leading side gear 21 engages with the idler gear 31.

The side gears 21 and 22, which were bridging the power through the connection to the bridge gear 31 , returns to the neutral position by means of a reverse operation of the side gear disjunction device 60a, as soon as the side gears 32 and 33 of the output gear system 30 shift from the neutral position to the lowest gear 11a of the input gear 11 and engage with the lowest gear 11a.

There is an output shaft S3 at an upper side of the input shaft S1 , which is disposed at an angle corresponding to the gradient of the input gear 11. An output gear system 30 is disposed thereon. The output gear system 30 is composed of an idler gear 31 mounted on a front end of the output shaft S3, moving side gears 32 and 33 for substantially shifting the output shaft S3, and a bridge gear 34 for delivering a rotational force from the output shaft S3 to the side gear disjunction device 70.

A groove 35 is formed in the output shaft S3 at a place where the circumference is halved, to prevent the side gears 32 and 33 from deviating toward sides when the side gears 32 and 33 move over the gear train for respective speeds after engaging with the lowest gear 11a, in which the protrusions of the side gear 32 and 33 ride on the groove 35 in an axial direction, as in Fig. 2. The side gears 32 and 33 have protrusions 36 formed at both ends of the divided face to prevent them from taking off in a center direction by hanging on the groove 35. The side gears 32 and 33 stay at a front neutral position of the lowest gear

11a in the input gear 11 on the output shaft S3 and then, when the power from the input gear 11 is applied to the idler gear 31 via the output bridge device 20, move to and engage with the lowest gear 11a by the side gear disjunction device 70. Thereafter, the side gears sequentially move to the highest gear 11 n by the side gear disjunction device 70 whenever the speed of the input gear 11 increases to deliver the power from the gears 11a to 11 n to the output shaft S3 for respective steps. If a rotation number of the input gear 11 decreases, the side gears move sequentially from the highest gear 11 n to the lowest gear 11a by the side gear disjunction means 70 so that the power of the gear connected at that time enables the output shaft S3 to be shifted at a low speed. The side gears are of a side gear type having a halved circumference, like the above side gears 21 and 22.

An end of a push bar 66a or 66b dependent on the side gear disjunction device 70 is hanged on a front face of the side gear 32 and a rear face of the side gear 33, and accordingly a force for moving the side gears 32 and 33 is efficiently delivered. A push bar groove 35 is formed which blocks the side gears 32 and 33 from departing the control of the side gear disjunction device 70 even upon high speed rotation. The push bar groove 35 is formed at an immediate point between the side gears 21 and 22 and increases reliability in the operation by two controls of the push bar 66a or 66b per one rotation (see Fig. 3). In Fig. 4, the reverse gear system 40 is disposed at an opposite side of the output bridge device 20. The launching shaft S4 is also disposed corresponding to the gradient of the input gear 11 and is composed of a reverse gear 41 and an idler 42. The reverse gear 41 reversely rotates the output shaft S3 using the power from the input gear 11 delivered via the idler 42 when the side gears 21 and 22 and the output gears 32 and 33 remain at the neutral position. Even in the case where the power is applied to the output shaft S3, and the reverse gear always engages with a low speed gear train selected for the reverse in the input gear 11 to perform idle rotation. At this time, if a reverse button or a reverse lever disposed at the front of a driver's seat is operated when the side gears 21 and 22 and the output gears 32 and 33 remain at the neutral position, the side gears 51 and 52 of the reverse bridge device 50 move to and engage with the idler gear 31 of the output shaft S3, so that the rotation direction of the power delivered from the input gear 11 is changed to the idler 42 and the power is delivered to the output shaft S3.

In Fig. 5, the reverse gear 41 always engages with the input gear 11 and the idler 42 always engages with the bridge gear 53 of the reverse bridge device 50.

Returning to Fig. 4, there is a bridge shaft S5 disposed at the vicinity of the reverse gear system 40, which corresponds to a gradient of the input gear 11 , and a reverse bridge device 50 is disposed therein. The reverse bridge device 50 is composed of two side gears 51 and 52 disposed on a front end of the bridge shaft S5 so that divided faces obtained by dividing a circumference face each other but maintain a gap by its thickness upon rest, and a bridge gear 53 disposed at a rear end portion of the bridge shaft S5. The structure of the bridge shaft S5 and the side gears 51 and 52 is the same as that shown in Fig. 2.

The leading side gear 51 waits at a neutral state and then advances by means of a side gear disjunction device 60b for a reverse bridge device and smoothly engages the idler gear 31 to normally allow backward power to the idler gear, in which the idler gear naturally had a heavy load because of its stationary state. The following side gear 52 advances by means of the side gear disjunction device 60b to join together the leading side gear 51 so that a circular gear form is attained to normally bridge the backward power, as soon as the leading side gear 51 engages with the idler gear 31. The side gears 51 and 52 are connected to the idler gear 31 to bridge the reverse power and then, when a brake is applied, return away from the idler gear 31 by means of the side gear disjunction device 60b.

The side gear disjunction devices 60a, 60b and 70 will now be described. In Fig. 1 , the side gear disjunction device 60a is positioned in a line beside the output bridge device 20 and, when it oscillates, advances the side gears 21 and 22 to engage with the idler gear 31 so that the power is applied to the output shaft S3. Immediately after the power from the input gear 11 is applied to the output shaft S3, the side gear disjunction device enables the side gears 21 and 22 to return to the neutral position so that power transmission via the output bridge device 20 stops. The side gear disjunction device 60b of Fig. 3 is positioned in a line beside the reverse bridge device 50 and upon reverse, advances the side gears 51 and 52 to engage with the idler gear 31 , so that reverse power is delivered to the output shaft S3. When the brake is applied, the side gear disjunction device 60b returns the side gears 51 and 52 to the neutral position so that reverse power is not delivered via the reverse bridge device 50. These side gear disjunction devices 60a and b only differ in applying positions and are the same in the structure.

The above-stated side gear disjunction devices 60a and b have, as essential elements, a pinion 63a mounted on the rear end of the screw bar driving means 61 and the screw bar, a pipe shaft 64, a slider 65, a guide 67 and a driven gear 69. The driving means 61 has two solenoids having an idler of the rack 62 at given intervals in a case to rotate the screw bar 63 left or right so that the slider 65 advances or returns.

Fig. 6 shows an exploded view of a portion that excludes the screw bar driving means 61. In this figure, a screw bar 63 is inserted into the pipe shaft 64 in a rotatable manner to support the pipe shaft, and the pinion 63a engages with two racks 62 at an opposite side and when the rack 62 advances and retreats, rotates left or right to allow the screw bar 63 to advance or return the slider 65 by the advance and retreat width of the rack.

The pipe shaft 64 is held by inserting a driven gear 69 into a second half portion of the pipe shaft, and a slider guide 64b is integrally formed in a first half portion of the pipe shaft to support the slider 65 so that the rotation and straight movement to an axial direction of the slider 65 is possible. The driven gear 69 always engages a bridge gear 23 of the output bridge device 20 or a bridge gear 53 of the reverse bridge device 50 to rotate the pipe shaft 64 and the slider 65. The ratio of the rotation number of the driven gear 69 to that of the bridge gears 23 and 53 is 1 :1. This is intended for the slider 65 to influence on the side gears 21 and 22 or 51 and 52 even upon high speed rotation by allowing two push bars 66a and b per direction to be contiguous to and press respective grooves 26 and 54 oppressively and certainly whenever the slider 65 rotates with the side gears 21 and 22 or 51 and 52 in the 1 :1 ratio. The slider guide 64b delivers a rotational force of the bridge gears 23 and 53 to the slider 65 and, at the same time, allows the slider 65 to move in the axial direction according to an operation of the screw bar 63.

The slider 65 provides stability by advancing or returning the side gear 21 and 22 or 51 and 52 through rotation and axial movement in a prescribed range, a female screw 65a corresponding to the screw bar 63 is formed at a center thereof, and a guide groove 67 for guiding the slider guide 64b is positioned at an outside of the female screw 65a. Further, a guide groove 65b into which the slider guide 64b is inserted is formed at an outside of guide groove 67. An axial movement width of the slider 65 is such that the leading and following side gears 21 and 22 or 51 and 52 are connected to the idler gear 31 and the side gears 21 and 22 or 51 and 52 are positioned before and after it with a gap on the order of the thickness at the neutral position.

The push bars 66a and 66b are individually contiguous to front faces of the leading side gears 21 and 51 or rear faces of the following side gears 22 and 52. The push bars 66a and 66b apply an elastic pressure to them so that an engagement state with the idler gear 31 is stably maintained and advances the side gears 21 and 22 or 51 and 52 by means of a movement force having an axial direction of the slider 65 to allow them to engage with the idler gear 31 or to return them to the neutral position through separation from the idler gear 31. The push bars 66a and 66b are powerful coil springs, and are attached before and after a point where the circumferential surface of the slider 65 is halved. The front push bar 66a is for returning the side gear 21 and 22 or 51 and 52 and the rear push bar 66b is for advancing the side gear 21 and 22 or 51 and 52. A distance between the front and rear push bars 66a and 66b is determined by taking consideration into a distance when the side gears 21 and 22 or side gears 51 and 52 remain at the neutral position and a distance at which the idler gear 31 can be simultaneously engaged.

A hole 67a punched at the rear end of the guide groove 67 passes through a front end of the screw bar 63 upon assembling and prevents axis department outside of the hole by a method such as a coking or the like. Fig. 7 shows a change occurred when a slider 65, which was rotating, advances in a direction indicated by an arrow D. The side gear 22, which is present behind, rotates in an opposite direction of the slider 65 and approaches the slider 65, which the push bar 66b' is contiguous to and elastically push a rear face of the side gear. Fig. 8 shows that situation. Such a state continues until the push bar 66b' and the side gear 22 are disengaged from each other. As a result, the side gear 22 pushed by elastic pressure of the push bar 66b' approaches the leading side gear 21 and returns to a posture before division. When the slider 65 moves to the opposite side of the arrow D, the side gears 21 and 22 return by the push bar 66a. Explanation will be now given on a side gear disjunction device 70 for an output gear system. The side gear disjunction device 70 is positioned in a line outside of an output gear system 20. When launching, the device moves and engages the side gears 32 and 33 to and with an input gear 11 so that shifted power is outputted. When halting, the device returns the side gears 32 and 33 to the neutral position. There is a difference in that a travel width expanding means, which can expand a travel width of the slider 65, is added to the above side gear disjunction device 60a and 60b.

In Fig. 9, a corn 631 with a spline is formed at a center of the rear end of the screw bar 63. The corn 631 is an element for enabling a pinion 63a disconnected from the screw bar 63 to leave and then return to the screw bar 63 so that the screw bar 63 is rotated by the force of the bridge gear 23.

The pinion 63a has a corn groove 633 for enabling the pinion to return at any time so that it is inserted into the corn 631 after the pinion is disconnected from the screw bar 63. An idler 632 is integrally formed on the co-axis. The idler 632 is substituted for a ram for the electro-magnet 635.

The electro-magnet 635 is attached to a transmission housing. When supplied with an electrical current, the electro-magnet absorbs the idler 632 so that the pinion 63a deviates from the screw bar 63. The return spring 634 returns the pinion 63a to the screw bar 63 immediately when the electro-magnet 635 is not supplied with the electrical current. An idler activity hole 636 is formed in the electro-magnet 635.

In Fig. 10, when a current does not flow into the electro-magnet 635, the pinion 63a is inserted into the corn 631 and a rack 62 of the screw bar driving means 61 is also engaged, such that the screw bar 63 is rotated and a function of the slider 65 is normally performed by the screw bar 63.

However, if the electro-magnet 635 is supplied with the electric current, the situation changes. If the electro-magnet 635 is supplied with the electric current at any time, then the idler 632 is magnetized at once to draw and deviate the pinion 63a from the corn 632 of the screw bar 63, as shown in Fig. 11. Thus, when the pinion 63a leaves, it is also deviated from the rack 62.

Accordingly, at this time, the screw bar driving means 61 cannot rotate the screw bar 63. Consequently, the screw bar 63 does not move at a position at the time when the pinion 63a has left and also the slider 65 does not move any more. Then, if the current is not supplied to the electro-magnet 635, the pinion 63a returns to the return spring 634 at once for engagement to normally exhibit its function.

Such disconnection of the pinion 63a make it possible to overcome travel width limit in the slider 65 movable per one process of the rack 62, so that an available transmission range on the input gear 11 by the side gears 32 and 33 is maximized.

INDUSTRIAL APPLICABILITY

As described above, the present invention comprises an input gear having gears given for respective rotational speeds at a circumferential surface of a corn, an output bridge device having a gear for delivering the power from the input gear to an output shaft, which is composed of a side gear, an output gear system, and a reverse bridge device, thereby simplifying a disjointing process by the gears for respective speeds of the subsequent device or the input gear. As a result, vibration and noise are very small in spite of mechanical contact upon power application and transmission, and the backwardness as well as the transmission is also very silent.

Further, there are many multi-step gears given to the circumferential surface of the single input gear and there is no crevice between gear steps, thereby obtaining excellent transmission capability and high transmission efficiency. Accordingly, a fuel saving effect is excellent.

Claims

WHAT IS CLAIMED IS:

1. A machinetype transmission for a car, comprising: a cone type input gear with transmission gears formed on a circumferential surface thereof for respective speeds; an output bridge device with a side gear, which delivers the power from the input gear to an output shaft upon launching to allow the side gear to engage with a lowest gear of the input gear and then returns; an output gear system for delivering the power to the output shaft, the power being changed when the side gear moves and reaches to the lowest gear of the input gear by an output bridge device and then travels on the output shaft according to a rotational speed of the input gear; a reverse gear system for always engaging with the input gear to idly rotate, and then enabling the side gear to engage with an idler gear of the output gear system so that a reverse force is delivered to the output shaft when the output bridge device and the side gear of the output gear system remain at an neutral position and a reverse command is issued; a side gear disjunction device for the output bridge device; a side gear disjunction device having a travel width expanding means for the side gear for use in the output gear system; and a side gear disjunction device for the reverse bridge device.