JPH0642122Y2 - Device for preventing generation of meshing hit sound of transmission gear in transmission - Google Patents

Description

[Detailed Description of the Invention] A. Purpose of the Invention (1) Field of Industrial Use The present invention includes a plurality of driven gears that are rotatably supported by a driven shaft and can be coupled to the driven shaft via a synchronizing mechanism. In a transmission including a plurality of drive gears provided on a drive shaft so as to be constantly meshed with each driven gear, a meshing striking sound of a speed change gear for preventing generation of a meshing striking sound between the drive gear and the driven gear. Generation prevention device.

(2) Related Art Conventionally, a gear that prevents generation of a meshing sound of a transmission gear in a transmission is known from, for example, Japanese Utility Model Laid-Open No. 62-2860.

(3) Problem to be Solved by the Invention In the above-mentioned conventional structure, the outer periphery of the elastic resistance member fixed to the driven shaft is elastically contacted with the driven gear, thereby giving rotational resistance to the driven gear. It has become. Therefore, the elastic resistance member is required for each driven gear, and the set dimension of the elastic resistance member is limited to a relatively small range.

The present invention has been made in view of such circumstances, and in order to prevent the generation of meshing striking sound by reducing the number of parts, the meshing of a transmission gear in a transmission having a high degree of freedom in setting a rotational resistance value is achieved. It is an object of the present invention to provide a hammering sound generation preventing device.

B. Configuration of the Invention (1) Means for Solving the Problems The present invention includes a plurality of driven gears rotatably supported by the driven shaft and connectable to the driven shaft through a synchronizing mechanism, and each driven gear. In a transmission including a plurality of drive gears provided on a drive shaft so as to be constantly meshed, a friction resistance member is provided between a pair of driven gears adjacent to each other with different gear ratios. It is characterized in that they are in frictional contact with each other.

(2) Action The pair of driven gears are rotationally driven by the drive shaft via the corresponding drive gears. At that time, the pair of driven gears relatively rotate due to the difference in gear ratio. Along with this relative rotation, a frictional resistance acts between the two driven gears via the frictional resistance member that makes frictional contact between them, and this frictional resistance causes the teeth of each driven gear to correspond to the teeth of the corresponding drive gear. Since it is pressed against the portion, even if there is a change in the transmission torque, no meshing striking sound is generated between the two tooth portions.

(3) Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the drawings. A transmission case 1 of a transmission forming a part of an engine mounted on a vehicle includes a transmission shaft 2 and a driven shaft which are parallel to each other. 3 is rotatably supported, the drive shaft 2 is interlocked and connected to an engine body (not shown), and the driven shaft 3 is interlocked and connected to drive wheels (not shown).

Between the drive shaft 2 and the driven shaft 3, a gear train of a plurality of shift stages that can be selectively established, that is, a first speed gear train G ₁ , a second speed gear train G ₂ , a third speed gear train G ₃ and a third speed gear train G ₃ A fourth speed gear train G _{4 and the} like are provided. Of these gear trains G ₁ ~G _4, for example, the second-speed gear train G ₂ is the drive shaft 2 to the drive gear 4 is driven gear 5 is driven shaft 3 which meshes constantly with the drive gear 4 with integrally provided The third speed gear train G ₃ is rotatably supported by the second speed gear train G ₂ and is adjacent to the second speed gear train G _2. A driven gear 7 that meshes with the driven shaft 3 is rotatably supported by the driven shaft 3. Further, a reverse shaft 25 is fixed to the mission case 1 in parallel with the drive shaft 2 and the driven shaft 3, and is mounted on a drive gear 26 integrally provided on the drive shaft 2 and a sleeve 29 of a synchronizing mechanism 17 described later. interlockable idle gear 28 to the driven gear 27 provided that, in the movable between engaged position and disengaged position is supported in the reverse shaft 25, the reverse gear train G _r by the gears 26, 27, 28 Is configured.

The driven gear 5 of the second speed gear train G ₂ and the third speed gear train G ₃
Distance collars 8 and 9 are fitted to the driven shaft 3 at positions corresponding to the driven gears 7, and both driven gears are provided by interposing needle bearings 10 and 11 between the distance collars 8 and 9. 5,7 are rotatably supported. Moreover, a stopper ring 12 for determining the axial position of the distance collars 8 and 9 and the axial position of the driven gears 5 and 7 is interposed between the distance collars 8 and 9.

Between the first and second speed gear trains G ₁ and G ₂ and the driven shaft 3,
A synchro mechanism 17 capable of switching between a state in which both gear trains G ₁ and G ₂ are selectively connected to the driven shaft 3 and a state in which the connection is released is interposed, and the third and fourth speed gear trains G ₃ , G ₄ and the driven shaft 3 are provided with a synchro mechanism 18 capable of switching between a state in which both gear trains G ₃ , G ₄ are selectively connected to the driven shaft 3 and a state in which the connection is released. Set up. Since these synchro mechanisms 17 and 18 are well known in the art, a detailed structural description thereof will be omitted, but the hub 1 which is a component of the synchro mechanisms 17 and 18 is omitted.
3, 14 are connected to the driven shaft 3 via splines 15 and 16 between the first and second speed gear trains G ₁ and G _{2 and} between the third and fourth speed gear trains G ₃ and G ₄ , respectively. 2nd and 3rd speed gear train
G _2, wherein the hub 13 side so as to form a part of the synchronizing mechanism 17, 18 spline teeth 5a of the driven gear 5 and 7 in G _3, 7a and cone portion 5b, 7b are provided. Thus, the synchronization mechanism 1
The second speed gear train G ₂ is established when the hub 13 and the driven gear 5 are connected via 7 and the third speed gear train G ₂ is connected when the hub 14 and the driven gear 7 are connected via the synchronizing mechanism 18.
G ₃ is established.

The gear ratios of the driven gears 5 and 7 adjacent to each other are different, and an annular friction resistance member 19 is provided between these driven gears 5 and 7. That is, an annular groove 20 coaxial with the driven shaft 3 is provided on the end surface of the driven gear 5 on the driven gear 7 side.
A cylindrical portion 21 that coaxially projects into the annular groove 20 is coaxially provided on the shaft. Thus, the friction resistance member 19 is interposed between the inner peripheral surface of the annular groove 20 and the outer peripheral surface of the cylindrical portion 21, and makes frictional contact between them.

The friction resistance member 19 is formed of an elastic material such as rubber or synthetic resin into a ring shape with a substantially U-shaped cross section, and a core metal 22 formed into a ring shape with a substantially L-shaped cross section. It will be strengthened. The outer peripheral portion of the friction resistance member 19 is press-fitted and fixed in the annular groove 20. Further, the inner peripheral portion of the friction resistance member 19 is strongly slidably contacted with the outer periphery of the cylindrical portion 21 by the spring 23 wound around the outer periphery thereof.

Next, the operation of this embodiment will be described. The driven gear 5
Is not connected to the driven shaft 3 and the driven shaft 7 is driven in a state where the driven gear 7 is not connected to the driven shaft 3, the driven gear 5 and the driving gear 6 which are always meshed with the driving gear 4 are driven. The driven gear 7, which is constantly meshed with, idles around the driven shaft 3 via needle bearings 10 and 11. Since the gear ratios of the two driven gears 5 and 7 are different from each other, they are rotating relative to each other, and due to the difference in the number of rotations, friction occurs between the driven gears 5 and 7 via a friction resistance member 19. A resistance acts, and the friction resistance causes the tooth portions of the driven gears 5 and 7 to be pressed against the tooth portions of the corresponding drive gears 4 and 6, respectively. Therefore, even if torque fluctuation occurs in the drive shaft 2, each driven gear 5,
It is possible to suppress the generation of a meshing hit sound between the tooth portion of 7 and the tooth portion of the corresponding drive gears 4 and 6.

By the way, the frictional resistance member 19 for preventing the generation of the mesh hitting sound is provided between the driven gears 5 and 7 which are adjacent to each other.
It is sufficient to provide only one, and therefore, compared to the conventional one in which one elastic resistance member is required for each driven gear 5 and 7,
The number of parts is reduced.

Further, since the friction resistance member 19 is provided between the driven gears 5 and 7 adjacent to each other, the size of the conventional elastic resistance member provided between the driven gears 5 and 7 and the driven shaft 3 is the same as that of the driven gear 5. The size can be made larger than the case where it depends on the inner diameters of 7 and 7. Therefore, it is possible to increase the frictional resistance value by relatively increasing the thickness of the frictional resistance member 19, and further increase the contact area of the frictional resistance member 19 with the driven gears 5 and 7 to increase the frictional resistance value. It is possible to increase the resistance torque, and it is possible to increase the resistance torque even if the frictional resistance values are the same, rather than increasing the diameter of the frictional resistance member 19 relatively.

In the above embodiment, the second speed gear train G ₂ and the third speed gear train
Although the case where the friction resistance member 19 is provided between the driven gears 5 and 7 of G ₃ has been described, the friction resistance member is disposed at any position as long as it is between the driven gears adjacent to each other and having different gear ratios. May be done. The friction resistance member may be made of metal as well as elastic material such as rubber or synthetic resin.

C. Effect of the Invention As described above, according to the present invention, a pair of driven gears adjacent to each other with different gear ratios are brought into frictional contact with each other via a friction resistance member provided between the driven gears. Therefore, friction resistance acts between the driven gears that rotate relative to each other due to the difference in gear ratio via the friction resistance member, and the tooth resistance of each driven gear is caused by the friction resistance. Therefore, even if there is a change in the transmission torque, no meshing striking sound is generated between the two tooth portions. Moreover, since one friction resistance member can be commonly used for a pair of driven gears having different gear ratios, the number of parts can be reduced as compared with the conventional structure in which a rotation resistance member is individually provided for each driven gear. It is possible to contribute to the reduction, and because the friction resistance member is arranged between both driven gears, it is possible to set the size of the friction resistance member to be relatively large, and to increase the degree of freedom in setting the friction resistance force. be able to.

[Brief description of drawings]

The drawing is a vertical sectional side view of a main part of a transmission to which the present invention is applied. 2 ... drive shaft, 3 ... driven shaft, 4,6 ... drive gear, 5, 7 ...
… Driven gear, 17,18 …… Synchronizing mechanism, 19 …… Friction resistance member

Claims (1)

[Scope of utility model registration request] 1. A plurality of driven gears (5, 7) rotatably supported by a driven shaft (3) and connectable to the driven shaft (3) through a synchronizing mechanism (17, 18), and each driven gear. Gears (5,7)
A plurality of drive gears (4, 6) provided on a drive shaft (2) to be constantly meshed with each other, a pair of driven gears (5, 7) adjacent to each other with different gear ratios. Is provided between the driven gears (5, 7) of the friction resistance member (1
9) A device for preventing the generation of a meshing hit sound of a speed change gear in a transmission, which is brought into frictional contact via.