JP2001099277A - Friction gear structure of transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the generation of gear tooth hammering noise between an output shaft and a counter drive gear during high speed running where a main shaft and an output shaft are directly intercoupled and improve an assembly property through stable rotation of an output shaft by a method wherein a reduction driven gear is previously widely engaged with a reduction drive gear even when engagement of a friction gear does not match with the reduction drive gear during assembly of the output shaft. SOLUTION: A friction gear to generate a friction force to prevent the generation of gear tooth hammering noise is provided with a gear tooth hammering noise preventing mechanism situated at the side portion on the propulsion shaft side of the reduction driven gear fixed on an output shaft.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a friction gear structure of a transmission, and more particularly to a friction gear structure of a transmission that can prevent gear rattle in a subtransmission portion of the transmission.

[0002]

2. Description of the Related Art In a vehicle, a power transmission device including a transmission and a transfer as a sub-transmission portion for distributing the driving force is provided in order to take out a driving force generated by an engine in accordance with a driving state. Provided.

Such transmissions include a gear type transmission and a belt type transmission, and a gear type transmission having a small transmission loss of driving force is often used. This gear type transmission has a plurality of speed change gear trains, and by switching the gear trains and meshing the gears of each stage, the driving force of the engine is converted as desired according to the running conditions. I'm taking it out.

In a gear type transmission, there is a backlash between the gears in a pair of idle gears in which the driving force is not transmitted, and therefore, fluctuations in engine torque due to combustion are transmitted as rotational fluctuations. However, the idle rotation of the gear pair causes backlash-induced tooth-punching phenomena due to the rotation fluctuation, and the gear-punching noise is generated.

That is, as shown in FIG. 11, in a sub-transmission portion (hereinafter, referred to as "transfer") 102 of a gear type transmission, the main transmission 104 is located on the same axis as a main shaft 104 on the engine (not shown) side. The end portion of the shaft 104 is
An output shaft 110 on the side of a propulsion shaft (not shown), which is rotatably held by a shaft-side needle bearing 108, is supported in an output bearing 114 held on a transfer case 112, and is provided inside the housing 6. A counter shaft 116 is supported and provided in parallel with the shaft 110 by a counter bearing 118 held by a transfer case 112, and a transfer low gear 120 is mounted on the main shaft 104 by a gear side needle bearing 122.
The counter shaft 116 is provided with a transfer counter gear 125 on needle bearings 123-1 and 123-.
2, the transfer counter gear 12
5 is provided with a transfer counter low gear 124 meshing with the transfer low gear 120 and a reduction drive gear 126 on the output shaft 108 side, and a reduction driven gear 128 meshing with the reduction drive gear 126 is fixedly provided on the output shaft 108, In the case of traveling (high ratio), the main shaft 104 and the output shaft 110 are directly connected, and in the case of low speed traveling (low ratio), the main shaft 104 and the output shaft 110 are connected to the transfer counter gear 124 and the reduction drive gear of the counter shaft 116. High / low speed switching mechanism 130 connected via 126
Is provided. The high-low speed switching mechanism 130 includes a reduction hub 134 in which a spline 132 for a sleeve is formed on the outer peripheral surface by spline fitting with the main shaft 104, and a main dock 1 fixed to the transfer gear 120.
And an output dock 138 fixed to the reduction driven gear 128 and corresponding to the main dock 136.
A reduction sleeve 140 that moves axially on the sleeve spline 132 and selectively fits into the main dock 136 and the output dock 138; and a reduction fork 142 that moves the reduction sleeve 140 in the axial direction. are doing.

In the transfer 102, when the vehicle is running with the main shaft 104 and the output shaft 110 directly connected during high-speed running, fluctuations in engine torque from the engine are transmitted as rotation fluctuations and idle. A gear tooth hitting noise corresponding to the backlash is generated between the transfer low gear 120 and the transfer counter gear 124 which are the gear pairs, and between the reduction drive gear 126 and the reduction driven gear 128.

In order to solve this problem, a friction gear 144 is provided between the transfer low gear 120 and the transfer counter gear 124. The friction gear 144 has one or more teeth than the number of teeth of the transfer counter gear 124, and is pressed against the side surface of the transfer counter gear 124 by a disc spring 146 as a spring to generate a frictional force. In addition, the backlash between the gears in the rotation direction is reduced, and the occurrence of gear tooth tapping noise is prevented.

As shown in FIG. 12, on the high / low speed switching mechanism 130 side (front side of the vehicle) of the reduction driven gear 128, there is a structure in which another friction gear 148 is attached by another disc spring 150. .

As a structure of a transfer for preventing generation of such gear teeth hitting sound, for example, Japanese Unexamined Patent Publication No.
No. 45, and Japanese Utility Model Laid-Open No. 5-50225. Japanese Patent Application Laid-Open No. 9-93645 discloses a configuration in which a low-speed gear or a high-speed gear is selectively coupled to an output shaft without dividing the output shaft. 5-5022
In the device disclosed in Japanese Patent Application Laid-Open No. 5 (1999) -1990, a friction gear is brought into pressure contact with a side surface of a driven-side main gear in order to eliminate backlash between the driven-side main gear and the driven-side main gear.

[0010]

By the way, conventionally, in the structure of the transfer for preventing the generation of the gear teeth hitting sound,
As shown in FIG. 12, when the friction gear 148 is attached to the high / low speed switching mechanism 130 of the reduction driven gear 128 by the spring 150, the engagement position between the friction gear 148 and the reduction drive gear 126 is reduced as shown in FIG. The drive gear 126 is engaged with the reduction driven gear 128 prior to the friction gear 148.
As shown in FIG. 14, the position B at which the reduction driven gear 128 and the friction gear 148 can be engaged is shifted from the engagement position of the reduction drive gear 126. That is, the engagement of the friction gear 148 does not match the reduction drive gear 126. If the friction gear 146 is aligned with the reduction drive gear 126, the reduction drive gear 126 and the reduction driven gear 128 interfere with each other, making it impossible to assemble the output shaft 110 (and the reduction driven gear 128). If it is not rotated, it cannot be assembled. However, when the output shaft 110 is the transfer case 1
12, the output shaft 1 is positioned at the position shown in FIG.
While holding the transfer case 112 and the transfer case 112, it is difficult to rotate the output shaft 110 so that the reduction driven gear 128 meshes with the reduction drive gear 126, and there is a disadvantage that the assemblability is reduced.

[0011]

Therefore, in order to eliminate the above-mentioned disadvantages, the present invention provides a main shaft on the engine side and an output shaft on the propulsion shaft side on the same axis as the main shaft. A counter shaft is provided in parallel with the main shaft and the output shaft, and a transfer low gear is provided on the main shaft,
A transfer counter gear meshing with the transfer low gear is provided on the counter shaft, a reduction drive gear is provided on the output shaft side of the counter shaft, and a reduction driven gear meshing with the reduction drive gear is provided on the output shaft. In the case of traveling, the main shaft and the output shaft are directly connected, and in the case of low-speed traveling, the main shaft and the output shaft are connected via the transfer counter gear and the reduction drive gear of the counter shaft. In a friction gear structure of a transmission provided with a high-low speed switching mechanism, a friction gear for generating a frictional force so as to prevent gear rattling noise is provided on a side portion of the reduction driven gear on the side of the propulsion shaft. A sound prevention mechanism is provided.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS According to the present invention, since the friction gear is provided on the side surface of the reduction driven gear on the side of the propulsion shaft, the engine torque does not act when the main shaft and the output shaft are directly connected at high speed. The gear teeth hitting noise that is generated between the reduction drive gear on the output shaft side and the reduction driven gear on the counter shaft side can be reduced, and when the output shaft is assembled, the engagement of the friction gears matches the reduction drive gear. Even if it is not, since the reduction driven gear meshes with the reduction drive gear widely,
The output shaft can be rotated stably, and assemblability can be improved.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of the present invention; 1 to 9 show a first embodiment of the present invention. In FIG. 9, reference numeral 2 denotes an engine of a front engine rear drive (FR) -based four-wheel drive vehicle (not shown) as a vehicle, and reference numeral 4 denotes a manual transmission provided with a transfer 6 as an auxiliary transmission portion.

The transmission case 8 of the transmission 4 is connected to the engine 2. The transmission case 8 includes an upper transmission case 8-1 and a lower transmission case 8-2. The transmission case 10 is connected to the transmission case 8. The transfer case 10 includes a front transfer case 10-1 and a rear transfer case 10-2, which are connected by transfer case mounting bolts 12. The front transfer case 10-1 is shown in FIGS.
As shown in FIG. 5, the main body 10A and the case wall 10B have a main shaft insertion hole 10C, a counter shaft insertion hole 10D, and a front output shaft insertion hole 10E formed in the case wall 10B.

In the transmission 4, an input shaft 14 on the engine 2 side is provided so as to be pivotally supported by the transmission case 8. A main shaft 16 which supports the input shaft 14 on the same axis as the input shaft 14. And a rear output shaft 18 which is an output shaft that supports the main shaft 16 as a bearing, and is provided to be supported by the transmission case 8 and the transfer case 10.
Further, a counter shaft 20 is provided to be supported on the transmission case 8 in parallel with the input shaft 14, the main shaft 16 and the rear output shaft 18, and a reverse idler shaft 22 is provided in parallel with the main shaft 16 and the counter shaft 20. It is provided to support the case 8.

In the transmission 4, forward and reverse speed transmission gear trains 24 are provided between the input shaft 14, the main shaft 16, and the reverse idler shaft 22, respectively. Transmission mechanism 26 for switching transmission gear train 24
Is provided. A rear propulsion shaft (not shown) is connected to an output side end of the rear output shaft 18 that is supported by the transfer case 10. A drive sprocket 28 is supported on the rear output shaft 18.

In the transfer 6, the front output shaft 30 is supported by the front transfer case 10-1 and the rear transfer case 10-2 in parallel with the main shaft 16, the rear output shaft 18 and the counter shaft 20. Have been.
A front propulsion shaft (not shown) is connected to an output end of the front output shaft 30. Also, the front output shaft 30
, A driven sprocket 32 is spline-fitted at a position corresponding to the drive sprocket 28. A transfer chain 34 is wound around the drive sprocket 28 of the rear output shaft 18 and the driven sprocket 32 of the front output shaft 30.

In the transfer 6, as shown in FIG. 2, an end portion of the main shaft 16 on the same axis as the main shaft 16 on the engine 2 side is inserted into an insertion portion 36 by a shaft side needle bearing 38. A rear output shaft 18 on the rear propulsion shaft side, which is rotatably held, is supported by an output bearing 40 held by the transfer case 10, and the counter shaft 20 is transferred in parallel with the main shaft 16 and the rear output shaft 18. The transfer shaft 44 is supported and supported by a counter bearing 42 held by the case 10, the transfer shaft 44 is supported by a gear-side needle bearing 46 on the main shaft 16, and the transfer counter gear 47 is mounted on the counter shaft 20 by a needle bearing 49-1. 49
-2, and the transfer counter gear 4
A transfer counter low gear 48 meshing with the transfer low gear 46 and a reduction drive gear 50 on the rear output shaft 18 side are provided on the rear output shaft 18, and a reduction driven gear 52 meshing with the reduction drive gear 50 is fixedly provided on the rear output shaft 18. In the case of high-speed running (high ratio), the main shaft 16 and the rear output shaft 18 are directly connected, and in the case of low-speed running (low ratio), the main shaft 16 and the rear output shaft 18 are connected to the transfer counter low gear of the counter shaft 20. A high / low speed switching mechanism 54 connected via a reduction drive gear 50 and a reduction drive gear 50 is provided. The high / low speed switching mechanism 54 is fixed to the reduction hub 58 in which the spline 56 for the sleeve is formed on the outer peripheral surface by spline fitting with the main shaft 16, the main dock 60 fixed to the transfer low gear 44, and the reduction driven gear 52. The output side dock 62 corresponding to the main side dock 60 and the sleeve spline 56
A reduction sleeve 64 that moves axially upward and selectively fits into the main dock 60 and the output dock 62.
And a reduction fork 66 for moving the reduction sleeve 64 in the axial direction. The reduction fork 66 is axially moved by the axial movement of the high / low speed switching shaft 68.

The rear output shaft 18 is provided with a two-wheel / four-wheel synchronization mechanism 70 near the drive sprocket 28. The two-wheel and four-wheel synchronization mechanism 70 includes a two-wheel and four-wheel switching sleeve 72, a two-wheel and four-wheel fork 74, and a two-wheel and four-wheel switching shaft 76.
And

In the transfer 6, when the vehicle runs at a high speed when the main shaft 16 and the rear output shaft 18 are directly connected, the transfer low gear 44 and the transfer counter low gear 48 Between the reduction drive gear 50 and the reduction driven gear 52, a rattle noise is generated.

For this reason, between the transfer low gear 44 and the transfer counter low gear 48, the front friction gear 74 attached to the counter shaft 20 on the transfer counter low gear 48 side as in the conventional case.
Is provided. This front friction gear 74 is
The number of teeth is formed to be one more or less than the number of teeth of the transfer counter low gear 48, and is pressed against the side surface of the transfer counter low gear 48 by the front disc spring 76 as a spring to generate a frictional force. The backlash of the gears is reduced, and the occurrence of gear teeth hitting noise is prevented. The front friction gear 74 and the front disc spring 76 are supported on the counter shaft 20 by a front retainer 78. The front retainer 78 is provided with the counter shaft 2
Axial movement is prevented by the front circlip 80 fixed to zero.

In the first embodiment, as shown in FIG. 1, a gear tooth hitting prevention mechanism 82 is provided on the side surface 52A of the reduction driven gear 52 on the rear propulsion shaft side (rear side of the vehicle). . This gear tooth hammer prevention mechanism 82
A friction gear 84 in contact with a side surface 52A on the rear propulsion shaft side of the reduction driven gear 52;
A disc spring 86, which is a spring that presses against the second side and generates a frictional force so as to prevent gear teeth hitting sound, a retainer 88 that holds the friction gear 84 and the disc spring 86 on the rear output shaft 18, and a retainer 88 And a circlip 92 fixed to a clip groove 90 formed in the outer peripheral surface of the rear output shaft 18 so as to prevent the axial movement of the rear output shaft 18. As shown in FIG. 4, the friction gear 84 is formed such that the number of teeth 84A is one more than the number of teeth 52A of the reduction driven gear 52, and the reduction drive gear 50
Is to mesh with. Also, the friction gear 84
Is mounted by a disc spring 86 on the side surface of the reduction driven gear 52 on the rear propulsion shaft side and on the main shaft insertion hole 10C side of the case wall 10B of the front transfer case 10-1. The retainer 88 is formed in an L-shaped cross section, and has a shaft-side support portion 88A that is oriented in the axial direction so as to support the friction gear 84 and the disc spring 86 on the output shaft 18. Spring-side support portion 88 which is radially oriented so as to be supported from
B. A mounting recess 94 is formed in the side surface 52A of the reduction driven gear 52 to insert the distal end side of the shaft-side support portion 88A of the retainer 88.

Next, the operation of the first embodiment will be described.

In the case of high-speed running, the high-low speed switching mechanism 54
, The main shaft 16 and the output shaft 18 are directly connected,
Therefore, the driving force from the engine 2 is transmitted to the input shaft 14, the main shaft 16, the reduction hub 58, the reduction sleeve 64, the reduction driven gear 52, and the rear output shaft 18. At this time, no driving force is transmitted to the transfer counter gear 47 side, and the transfer counter gear
And the reduction drive gear 50 idles, and the backlash between the gears tends to generate rattle.

However, in the first embodiment, since the friction gear 84 is provided on the side surface 52A of the reduction driven gear 52 on the side of the rear propulsion shaft, a high-speed connection between the main shaft 16 and the rear output shaft 18 is provided. During traveling, gear teeth hitting noise generated between the rear output shaft 18 and the reduction drive gear 50 can be reduced.
On the transfer counter low gear 48 side, the gear friction noise is reduced by the front friction 74 and the front disc spring 76 as in the conventional case.

When the rear output shaft 18 is assembled, the engagement position (shown by A in FIG. 4) of the friction gear 80 is changed to the reduction drive gear 50 as shown in FIGS.
Even if it does not fit, the reduction driven gear 52
Can be widely meshed with the reduction drive gear 50, so that the rear output shaft 18 can be rotated stably and easily. Finally, as shown in FIGS. Since it can be engaged with the gear 50, its assemblability can be improved.

FIG. 10 shows a special configuration of the present invention, and shows a second embodiment.

In the following embodiment, portions having the same functions as those in the above-described first embodiment will be described with the same reference numerals.

The features of the second embodiment are as follows. That is, each tooth 84 of the friction gear 84
A has a one-sided curved guide surface 96A on one side and another sided curved guide surface 96B on the other side so that the teeth 50A of the reduction drive gear 50 can be easily inserted into A. Thereby, each tooth 84 of the friction gear 84
A wide groove 98 is formed between A and 84A so as to spread toward the reduction drive gear 50 side.

According to the structure of the second embodiment, the teeth 50A of the reduction drive gear 50 are
4 can be easily inserted from the wide groove 98 between the adjacent teeth 84A and the teeth 84A, and the assemblability can be improved.

[0031]

As is apparent from the above detailed description, according to the present invention, a friction gear for generating a frictional force so as to prevent gear teeth hitting noise is provided on a side portion of the reduction driven gear on the side of the propulsion shaft. In the case of high-speed traveling in which the main shaft and the output shaft are directly connected to each other, an attempt is made to occur between the reduction drive gear on the output shaft side and the reduction driven gear on the counter shaft side by providing the gear tooth hitting prevention mechanism provided. In addition to reducing the gear teeth hitting noise, when the output shaft is assembled, even if the engagement of the friction gear does not fit with the reduction drive gear, the reduction driven gear meshes widely with the reduction drive gear first, so the output The shaft can be rotated stably, and assemblability can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view of a gear tooth hitting prevention mechanism.

FIG. 2 is a cross-sectional view of a transfer before an output shaft is assembled.

FIG. 3 is a cross-sectional view of a transfer in the process of assembling the output shaft.

FIG. 4 is a diagram illustrating a meshable position in FIG. 3;

FIG. 5 is a cross-sectional view of the transfer after the output shaft is assembled.

FIG. 6 is a diagram illustrating a meshing state of gears after assembly.

FIG. 7 is a side view of a front transfer case.

8 is a front view of the front transfer case indicated by an arrow 8 in FIG. 7;

FIG. 9 is a cross-sectional view of a transmission including a transfer.

FIG. 10 is a view showing the shape of teeth of a friction gear according to a second embodiment.

FIG. 11 is a cross-sectional view of a conventional transfer.

FIG. 12 is a cross-sectional view in which a friction gear is conventionally provided on a high-low speed switching mechanism side of a reduction driven gear.

FIG. 13 is a cross-sectional view of a transfer in the middle of assembling a conventional output shaft.

FIG. 14 is a view for explaining positions where gears can be engaged in the related art.

[Description of Signs] 2 engine 4 transmission 6 transfer 10 transfer case 14 input shaft 16 main shaft 18 rear output shaft 20 counter shaft 44 transfer low gear 48 transfer counter low gear 50 reduction drive gear 52 reduction driven gear 54 high / low speed switching mechanism 82 gear Gear rattle prevention mechanism 84 Friction gear

Claims (4)

[Claims] An engine-side main shaft is provided, a propulsion shaft-side output shaft is provided on the same axis as the main shaft, a counter shaft is provided in parallel with the main shaft and the output shaft, and the main shaft is provided on the main shaft. A transfer gear is provided, a transfer counter gear is provided on the counter shaft for meshing with the transfer low gear, a reduction drive gear is provided on the output shaft side of the counter shaft, and a reduction is provided on the output shaft which is meshed with the reduction drive gear. A driven gear for directly connecting the main shaft and the output shaft when traveling at high speed, and connecting the main shaft and the output shaft for traveling at low speed with the transfer counter gear of the counter shaft and the reduction drive gear; Friction gear structure of transmission with high / low speed switching mechanism connected via A gear tooth-sound-preventing mechanism provided on a side surface of the reduction driven gear on the side of the propulsion shaft, wherein a friction gear for generating a frictional force to prevent gear teeth-sound is provided. Friction gear structure of the machine. 2. The friction gear has one tooth greater than the number of teeth of the reduction driven gear, and a spring is provided on a side surface of the reduction driven gear on the side of the propulsion shaft and on a transfer case side by a spring. 2. The output shaft is pressed against the output shaft.
2. The friction gear structure of the transmission according to 1. 3. The gear tooth hitting prevention mechanism includes: a friction gear that contacts a side surface of the reduction driven gear on the propulsion shaft side; a spring that presses the friction gear from the side surface to generate a frictional force; The transmission according to claim 1, further comprising a retainer that holds a gear and the spring on the output shaft, and a circlip fixed to the output shaft so as to prevent the retainer from moving in the axial direction. Friction gear structure. 4. The reduction gear according to claim 2, wherein the friction gear meshes with the reduction drive gear.
2. The friction gear structure of the transmission according to 1.