JP2533759B2 - Structure of continuously variable transmission - Google Patents

Description

TECHNICAL FIELD The present invention relates to the structure of a continuously variable transmission, and more specifically,
The present invention relates to a structure of a continuously variable transmission including a continuously variable transmission including a driving side pulley and a driven side pulley having variable effective pitch diameters respectively provided on an input shaft and an output shaft, and a belt connecting both pulleys.

(Prior Art) In a transmission of the type described above, a gear device for enabling switching of the output rotation direction, that is, switching of forward and backward travel is required. As this gear device, for example, as disclosed in JP-A-60-164061, a forward synchronization mechanism is provided between the drive gear of the gear device and the output side shaft, and the driven gear and the output side shaft are also provided. It is known that a reverse-direction synchronization mechanism is provided between and to enable switching between forward and backward movement.

(Problems to be Solved by the Invention) However, in the transmission disclosed in the above-mentioned Japanese Patent Laid-Open Publication, since the reverse gear is always in mesh as described above, the input with the reverse gear at the time of forward high speed traveling is performed. The relative speed with respect to the shaft increases, leading to a reduction in efficiency due to abrasion resistance. In addition, the size of the device increases due to the presence of the reverse synchronization mechanism.

For this reason, there is U.S. Pat.No.4,529,373 as a device in which a synchronizer is provided only on the forward drive side and no synchronizer is provided on the reverse drive side. Shifts the idle gear so as to mesh with the sleeve and the counter gear, which complicates the shift operation system.

Therefore, the present invention is a continuously variable transmission in which the efficiency, compactness and simplification of the device are improved by switching the forward / backward movement only by moving the sleeve without providing a synchronizer on the reverse side. It is intended to provide the structure of.

(Means for Solving the Problems) The present invention comprises a drive-side pulley and a driven-side pulley with variable effective pitch diameters provided on an input shaft and an output shaft, respectively, and a belt connecting both pulleys. In a structure of a continuously variable transmission including a continuously variable transmission, the input shaft is divided into a first part connected to an output shaft of an engine and a second part connected to the drive pulley, A driven gear is provided at an end portion of the two portions on the side of the first portion, and a reverse idle gear that meshes with the driven gear and a reverse counter gear that meshes with the reverse idle gear are provided on the second portion side. Is provided with a reverse gear arranged coaxially with the reverse counter gear by a reverse counter shaft, and the input is provided at an end portion of the first portion on the second portion side. A sleeve for spline fitting is provided so as to be slidable in the axial direction of the shaft, an outer gear is formed on the outer circumference of the sleeve so as to fit with the reverse gear, and an inner gear is engaged with the driven gear of the second portion. Is provided with a synchronization mechanism.

(Effects of the Invention) In the continuously variable transmission of the present invention, as described above, the synchronous mechanism is used in the forward transmission path as in the prior art, but the gear type switching mechanism is used in the reverse transmission path. Therefore, by not providing the synchronizer on the reverse side and switching the forward and backward movements only by moving the sleeve, the efficiency, compactness and simplification of the apparatus can be brought about.

(Embodiment) Hereinafter, a structure of a continuously variable transmission according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, the belt type continuously variable transmission 1 receives power from a prime mover (not shown) via a clutch 3 which is, for example, a fluid coupling attached to the shaft end of an output shaft 2 thereof. And drives the differential device 4 and has a continuously variable transmission device 10, an output gear device 30, and a reverse gear train 40 as main components, which are arranged in a case. Has been done.

The continuously variable transmission 10 includes a drive pulley 12 on an input shaft 11 arranged concentrically with the clutch 3, and a driven pulley 14 on an output shaft 13 arranged in parallel with the input shaft 11. An endless belt 15 is laid between the two, and the drive side and driven side pulleys 12 and 14 are both effective pitch diameter variable pulleys. That is, the drive side pulley 12 is
A fixed disk 12 formed integrally with or fixed to the input shaft 11.
a and a movable disk 12b slidable in the axial direction with respect to the disk 12a, both disks 12a, 12b
The belt 15 is sandwiched between the conical surfaces facing each other. Similarly, the driven pulley 14 is also composed of a fixed disk 14a integrally formed or fixed to the output shaft 13 and a movable disk 14b slidable in the axial direction with respect to the disk 14a. The belt 15 is sandwiched between the conical surfaces facing each other. And the movable discs on both pulleys 12,14
Hydraulic chambers 12c and 14c are provided on the backs of the belts 12b and 14b, respectively, and the movable disc 12b of the drive side pulley 12 is moved toward and away from the fixed disc 12a by the hydraulic pressure introduced into the hydraulic chamber 12c. Clamping position (effective pitch diameter)
Changes, which causes the drive pulley 12 and the driven pulley to change.
The rotation ratio between 14 and 14 is changed. At this time, also in the driven pulley 14, the movable disc 14b is moved by the hydraulic pressure introduced into the hydraulic chamber 14c and the spring 14d mounted in the chamber 14c so that the belt 15 is always kept in a required tension state. It has become.

The input shaft 11 is a first output shaft of the clutch 3.
The portion 11a and the drive side pulley 1 in the continuously variable transmission 10
It is divided into a second portion 11b provided with two.

A reverse gear train 40 is provided astride the first portion 11a and the second portion 11b of the input shaft, and the reverse gear train 40 is fixed to the end portion of the input shaft 11 on the second portion 11b side. Driven gear 45, idler gear 43 provided on idler shaft 42 and meshing with driven gear 45, counter gear 44 meshing with idler gear 43, and counter gear
A counter shaft 46 that supports 44 at one end and extends toward the first portion 11a side in parallel with the input shaft 11 and a reverse gear 41 fixed to a portion of the counter shaft 46 parallel to the first portion 11a are provided. .

The first portion 11a and the second portion 11b of the input shaft 11 are intermittently connected by a forward switching device (hereinafter referred to as a first switching device) 20, and the first portion 11a and the reverse gear 41 are switched for backward movement. A device (hereinafter referred to as a second switching device) 50 is connected and disconnected.

The first switching device 20 uses a known synchronization mechanism, and includes a clutch hub 21 formed at the end of the first portion 11a and a sleeve 22 spline-fitted to the hub 21.
And a key 23 provided between the sleeve 22 and the hub 21.
And a gear spline 24 fixed to the end of the second part 11b.
And a synchronizer ring 25 loosely fitted to the conical portion of the spline 24. When the sleeve 22 is slid to the second portion 11b side by the shift fork 26, that is, to the left in the drawing, the key 23 presses the synchronizer 25 against the conical portion of the gear spline 24, thereby causing the spline 24 And the rotation of the clutch hub 21 are synchronized, and the sleeve 22 is fitted to the gear spline 24 in this state, whereby the first portion 11a and the second portion 11a
The portion 12b is connected to form a forward drive system.

On the other hand, the second switching device 50 is formed integrally with the sleeve 22 and the spline 51 integrally formed with the clutch hub 21 at a position facing the reverse gear 41. And a drive gear 52 that can slide. This drive gear 52
Has an inner spline common to the inner spline of the sleeve 22 and an outer gear 53 on the inner peripheral surface thereof. And
When the drive gear 52 is slid to the right in the drawing by the shift fork 26 common to the sleeve 22, the inner spline thereof engages with the spline 51, and the external gear 53 of the drive gear 52 is the reverse gear 41. Engage,
A reverse drive system is formed via the reverse gear train 40. In addition, the spline 51 of this drive gear 52
In order to smoothly engage with the reverse gear 41, the first portion 11a of the input shaft 11 is provided with a neutral clutch 54 as shown. Also, when the drive gear 52 moves to the right to form the reverse drive system,
Since the sleeve 22 also moves to the right at the same time, the forward drive system is automatically disconnected.

The output shaft 13 provided with the driven pulley 14 of the continuously variable transmission 10 and the differential device 4 are always connected via the output gear device 30. That is, the output gear device 30 is
13 and a pair of intermediate gears 32 that are fixedly or integrally formed with the intermediate shaft 31 arranged in parallel with each other and meshed with each other,
33 and an output gear 34 that is integrally formed with or fixed to the first intermediate shaft 31, and the output gear 34 is meshed with the final gear 5 that drives the differential device 4.

 The above structure is schematically shown in FIG.

In the continuously variable transmission having the above-described structure, as described above, the forward transmission path uses the conventional synchronization mechanism, but the reverse transmission path uses the gear-type switching mechanism. Therefore, the forward / backward movement can be switched only by moving the sleeve without providing a synchronizer on the reverse side, thereby making the apparatus more efficient, compact and simple.

[Brief description of drawings]

The drawings show an embodiment of the present invention. FIG. 1 is a longitudinally developed side view of a continuously variable transmission, and FIG. 2 is a schematic view schematically showing the structure of the continuously variable transmission. 1 ... Belt type continuously variable transmission, 2 ... Motor output shaft, 3 ... Clutch, 5 ... Final gear, 10 ... Continuously variable transmission, 11 ... Input shaft, 12 ... Drive side pulley, 13 Output shaft, 14 driven pulley, 15 belt, 22 sleeve, 40 reverse gear train, 41 reverse gear, 42 idler shaft, 43 idler gear, 44 counter Gears, 45 ... Driven gears, 46 ... Counter shafts, 20 ... Forward switching devices, 50 ... Reverse switching devices, 52 ... Drive gears, 53 ... External gears.

Claims (1)

(57) [Claims] 1. A continuously variable transmission including a continuously variable transmission composed of a driving pulley and a vertical pulley having variable effective pitch diameters respectively provided on an input shaft and an output shaft, and a belt connecting both pulleys. In the structure of a transmission, the input shaft is divided into a first portion connected to an output shaft of an engine and a second portion connected to the driving pulley, and the first portion side of the second portion is divided. A reverse gear that meshes with the driven gear and a reverse counter gear that meshes with the reverse idle gear are provided on the second portion side, and a reverse gear is provided on the first portion side by a reverse counter shaft. A reverse gear arranged coaxially with the counter gear is provided, and a slide gear is slidably provided at an end portion of the first portion on the second portion side in the axial direction of the input shaft. A line-fitting sleeve is provided, an outer gear is formed on the outer circumference of the sleeve so as to fit with the reverse gear, and a synchronizing mechanism is provided on the inner circumference so as to engage with the driven gear of the second portion. The structure of a continuously variable transmission characterized in that.