KR20130093708A - Continuously variable transmission - Google Patents

Continuously variable transmission Download PDF

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Publication number
KR20130093708A
KR20130093708A KR1020110141300A KR20110141300A KR20130093708A KR 20130093708 A KR20130093708 A KR 20130093708A KR 1020110141300 A KR1020110141300 A KR 1020110141300A KR 20110141300 A KR20110141300 A KR 20110141300A KR 20130093708 A KR20130093708 A KR 20130093708A
Authority
KR
South Korea
Prior art keywords
transmission
low speed
continuously variable
speed
mode
Prior art date
Application number
KR1020110141300A
Other languages
Korean (ko)
Inventor
김상현
Original Assignee
엘에스엠트론 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 엘에스엠트론 주식회사 filed Critical 엘에스엠트론 주식회사
Priority to KR1020110141300A priority Critical patent/KR20130093708A/en
Publication of KR20130093708A publication Critical patent/KR20130093708A/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/02—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used
    • F16H61/0202—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing characterised by the signals used the signals being electric
    • F16H61/0248—Control units where shifting is directly initiated by the driver, e.g. semi-automatic transmissions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/66—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for continuously variable gearings
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/68—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for stepped gearings
    • F16H61/684—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for stepped gearings without interruption of drive
    • F16H61/686—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing specially adapted for stepped gearings without interruption of drive with orbital gears

Abstract

PURPOSE: A continuously variable transmission is provided to offer high efficiency by using a low speed mode in a low speed section. CONSTITUTION: A planet gear (230) increases or transmits engine power delivered from a static hydraulic transmission. A sub-transmission unit (240) decreases the engine power transmitted from the planet gear or a selective transmission unit (210) in a predetermined speed range. The selective transmission unit converts the transmission of a vehicle into a hydro-mechanical transmission (HMT) mode or a low speed mode. The HMT mode transmits the engine power to the static hydraulic transmission. The low speed mode transmits the engine power to the sub-transmission unit through a machinery power transmission path. [Reference numerals] (100) Engine; (210) Optional transmission unit; (230) Planet gear; (240) Secondary transmission unit; (300) Final operating unit

Description

CVT {CONTINUOUSLY VARIABLE TRANSMISSION}

The present invention relates to a continuously variable transmission for controlling a shift in a low speed section, and more particularly, a high efficiency shift even in a low speed section by adding an optional transmission that can switch the vehicle shift to the HMT mode or the low speed mode. It relates to a continuously variable transmission that can maintain.

Hydro-mechanical transmission (HMT) consists of a mechanical transmission that combines a hydrostatic transmission (HST) and a planetary gear.

A hydrostatic mechanical transmission is a power diverter transmission that generally varies the speed using a hydrostatic transmission, and is a transmission that can realize a stepless speed range by using one or more planetary gears. Accordingly, the hydrostatic mechanical transmission has been expanded to be applied to off-road vehicles such as bulldozers, armored vehicles requiring high loads and high power, construction equipment, agricultural tractors, and the like.

When a conventional hydrostatic mechanical transmission is applied to a vehicle and used, the efficiency and power transmission ratio of the hydrostatic transmission have a great influence on the overall transmission efficiency when the power is diverged from the planetary gear. Accordingly, there is a problem in that the efficiency of the transmission is greatly reduced in a specific speed range, particularly in a low speed section.

Patent Document 1: Korea Patent Registration 10-0475834 (Dimos Co., Ltd.) 2005. 03. 02. Summary, Claim 1, Drawing 1

An object of the present invention is to provide a continuously variable transmission that can maintain a high efficiency shift even if the speed of the vehicle is in a low speed section.

A continuously variable transmission for controlling a shift in a low speed section according to an embodiment of the present invention for achieving the above object, a hydrostatic transmission (HST) for transmitting the power of the low speed torque generated in the engine; A planetary gear for transmitting or increasing engine power branched from the hydrostatic transmission; A sub transmission portion for decelerating engine power transmitted from the planetary gear or the selective transmission portion to a predetermined speed range; And an optional transmission for converting an engine power to the hydrostatic transmission or a low speed mode for transmitting engine power to the sub transmission via a mechanical power transmission path without passing through the hydrostatic transmission.

In the selective transmission unit, a speed change stage capable of increasing or decreasing speed may be set.

The speed ratio of the low speed stage of the low speed mode may be determined according to the number of stages of the sub transmission part.

The continuously variable transmission may further include a mechanical gear transmission configured to manually select the HMT mode and the low speed mode.

The continuously variable transmission may further include a sensor for detecting a moving speed of the vehicle and a controller for driving the selective transmission unit based on the speed value detected by the sensor.

The continuously variable transmission of the present invention does not use the HMT mode in a low-speed section of low efficiency during low-speed operation of the vehicle, by using a low-speed mode, a mechanical power transmission method, it is possible to perform the operation of high efficiency.

In addition, the continuously variable transmission of the present invention has an effect of extending the RPM input range of the HST pump, which can be changed at the time of directly connecting the engine RPM, by setting a shift speed that can increase or decrease the speed at the selective shift portion of the input stage of the HST. have.

In addition, the continuously variable transmission of the present invention does not use the HST in the low speed power transmission section, there is an effect that the power loss due to the hydraulic pressure does not occur.

In addition, the continuously variable transmission of the present invention has an effect that the speed range is small and extremely limited in the low speed operation, so that fine speed control of the continuously variable speed is not required.

1 is a block diagram of a power transmission unit of a vehicle to which a continuously variable transmission according to an exemplary embodiment of the present invention is applied.
2 is a graph showing shift efficiency when using the continuously variable transmission of the present invention.

Hereinafter, a continuously variable transmission according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a configuration diagram of a power transmission unit of a vehicle to which a continuously variable transmission (CVT) according to an embodiment of the present invention is applied.

Referring to FIG. 1, a power transmission unit of a vehicle includes an engine 100, a continuously variable transmission 200, and a final driver 300. The rotational power generated by the engine 100 is shifted through the continuously variable transmission 200 to drive the final driver 300.

The continuously variable transmission 200 of the present invention includes an optional transmission 210, a hydrostatic transmission (HST) 220, a planetary gear 230 and a sub transmission 240.

The selective transmission unit 210 may selectively switch to the HMT mode or the low speed mode, and transmit the rotational power generated from the engine 100 to the hydrostatic transmission 220 in the HMT mode, and in the low speed mode, the engine 100 The rotational power of) is transmitted to the sub transmission 240 through the mechanical power transmission path without passing through the hydrostatic transmission 220.

In order to change the mode of the selective transmission unit 210, a mechanical gear shift unit (not shown) for manually selecting the HMT mode and the low speed mode may be further included.

On the other hand, in another embodiment of the present invention, a sensor (not shown) for detecting the moving speed of the vehicle, and a controller (not shown) for driving the selective transmission unit 210 based on the speed value detected by the sensor. May be included.

The hydrostatic transmission 220 transmits the power of the low speed torque by using the static characteristics of the fluid. The hydrostatic transmission 220 may be continuously variable, and this may be performed by adjusting the rotation angle of the swash plate of the hydrostatic transmission 220.

Since the volume of the pump changes due to the rotational angle of the swash plate, if the angle of the swash plate is 0, the HST pump rotates but no thrust occurs. If the angle of the swash plate is not 0, the thrust is generated in the forward or backward direction of the vehicle. Increasing the swash plate angle increases the output.

When the HMT mode is selected, the engine power is transmitted through the hydrostatic transmission 220 and the planetary gear 230, and the speed ratio can be adjusted through the swash plate angle of the hydrostatic transmission 220, thereby allowing stepless speed change. Do. The continuously variable shifting system is a system in which a shift stage of the vehicle is continuously performed, and thus the shift is smoothly performed according to the output of the engine 100, thereby reducing power loss occurring during shifting. Accordingly, there is no shift shock due to the gear shift, and because the speed of the engine 100 can be maintained independently of the wheels, the engine 100 can be optimally operated.

An optional transmission unit 210 installed at an input of the hydrostatic transmission 220 may have a shift speed capable of increasing / decreasing the speed. Through this, HST, which could not be changed when the hydrostatic transmission 220 is directly connected to the engine RPM, may be set. The RPM input range of the pump can be extended.

The planetary gear 230 transmits or increases engine power diverged from the hydrostatic transmission 220.

The auxiliary transmission unit 240 reduces the engine power transmitted from the planetary gear 230 or the selective transmission unit 210 to a predetermined speed range, and transmits it to the final driving unit 300.

The low speed stage of the low speed mode of the selective transmission unit 210 may have a speed ratio determined according to the number of stages of the sub transmission unit 240. For example, when the number of stages of the sub transmission unit 240 is four stages, The speed ratio can be used by determining the speed ratio up to 4 speeds.

2 is a graph showing shift efficiency when using the continuously variable transmission of the present invention.

2, the horizontal axis represents the moving speed of the vehicle, the vertical axis represents the engine power transmission efficiency of the continuously variable transmission.

Conventional HMT continuously variable transmission can use a high efficiency transmission in the sub-speed 2 to 3 range by combining the swash plate adjustment of the hydrostatic transmission (HST) and the planetary gear, but the low speed section of less than 0 to 1 km / hr (10 ), The transmission efficiency is very low due to the characteristics of the HMT continuously variable transmission. However, in the continuously variable transmission 200 having the selective transmission unit 210 of the present invention, the shift efficiency 20 may be maintained at a high efficiency by selecting a low speed mode in a low speed section.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, Of course.

100: engine
200: continuously variable transmission
210: optional transmission
220: hydrostatic transmission (HST)
230: planetary gear
240: sub transmission part
300: final drive unit

Claims (5)

A continuously variable transmission for controlling the shift in the low speed section,
Hydrostatic transmission (HST) for transmitting the power of the low speed torque generated in the engine;
A planetary gear for transmitting or increasing engine power branched from the hydrostatic transmission;
A sub transmission portion for decelerating engine power transmitted from the planetary gear or the selective transmission portion to a predetermined speed range; And
And an optional transmission for converting the engine power into the low speed mode for transmitting engine power to the sub transmission through a mechanical power transmission path without passing through the HMT mode for transmitting engine power to the hydrostatic transmission. Transmission. The continuously variable transmission as claimed in claim 1, wherein the selective transmission unit has a speed change stage capable of increasing and decreasing speed. The continuously variable transmission of claim 1, wherein a speed ratio of the low speed stage of the low speed mode is determined according to the number of stages of the sub transmission portion. The continuously variable transmission of claim 1, further comprising a mechanical gear transmission for manually selecting the HMT mode and the low speed mode. The continuously variable transmission of claim 1, further comprising a sensor for detecting a moving speed of the vehicle and a control unit for driving the selective transmission unit based on the speed value detected by the sensor.
KR1020110141300A 2011-12-23 2011-12-23 Continuously variable transmission KR20130093708A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020110141300A KR20130093708A (en) 2011-12-23 2011-12-23 Continuously variable transmission

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020110141300A KR20130093708A (en) 2011-12-23 2011-12-23 Continuously variable transmission

Publications (1)

Publication Number Publication Date
KR20130093708A true KR20130093708A (en) 2013-08-23

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Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020110141300A KR20130093708A (en) 2011-12-23 2011-12-23 Continuously variable transmission

Country Status (1)

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KR (1) KR20130093708A (en)

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