JP6330890B2 - Transmission reverse mechanism - Google Patents

Description

  The present invention relates to a reverse mechanism for a transmission provided in a vehicle, and particularly belongs to the field of gear drop prevention technology used for a manual transmission.

  Generally, as a manual transmission used in vehicles such as automobiles, a primary shaft connected to an engine via a clutch, and a secondary shaft arranged in parallel to the primary shaft and connected to drive wheels via a differential device And a plurality of forward shift gear trains are provided between these two shafts, and a reverse gear train is provided between the three shafts including an idle shaft arranged parallel to these two shafts. The thing of the structure provided with is known.

  In this type of transmission, the forward gear stage gear train is operated while the gear shift operation is running. Therefore, the gear on the primary shaft is always meshed with the gear on the secondary shaft, and the selected gear train is Whereas the constant meshing system in which the power is transmitted by the synchronizer is adopted, the reverse speed gear train in which the shifting operation is normally performed while the vehicle is stopped is the selective sliding system. That is, the reverse gear train is composed of a reverse primary gear fixed to the primary shaft, a reverse secondary gear fixed to the secondary shaft, and a reverse idle gear loosely fitted to the idle shaft. At the time of speed change operation, the reverse idle gear is engaged with the reverse primary gear and the reverse secondary gear in conjunction with the operation of the shift lever, and the reverse gear train is brought into the power transmission state.

  By the way, in the selective sliding type reverse gear train as described above, rattling of the bearing portion of the shaft provided with each gear, rattling of the fitting portion of the shaft and the gear, deflection of the shaft itself. For example, during transmission of power, the reverse primary gear and the reverse idle gear, and the reverse idle gear and the reverse secondary gear may mesh with each other in a relatively inclined state.

  Here, the inclination of the gear will be described with reference to FIG. In this description, the reverse primary gear, the reverse secondary gear, and the reverse idle gear are referred to as a primary gear, a secondary gear, and an idle gear, respectively.

  5 (a) and 5 (b) show a state where the meshing portion with the idle gear I is seen from the center of the primary gear P along the direction of transmission of power during driving (see FIG. 2, arrow x), and The state (refer FIG. 2, arrow y) which looked at the meshing part with the secondary gear S from the center of the idle gear I is each shown typically. In this example, in the former meshing portion, the idle gear I is inclined counterclockwise with respect to the primary gear P, and in the latter meshing portion, the secondary gear S is tilted relative to the idle gear I in the clockwise direction. ing.

  In the former meshing portion, the idle gear I is inclined relative to the primary gear P in the clockwise direction, and in the latter meshing portion, the secondary gear S is inclined relative to the idle gear I in the counterclockwise direction. possible. In any case, it is considered that the inclination of these axial centers is inclined so as to be balanced as a whole, and that the inclination of the gears at both meshing portions in the same direction in FIG. .

  Further, the primary gear P, the secondary gear S, and the idle gear I rotate in the A direction, the B direction, and the C direction, respectively, during driving, D indicates the power transmission direction, and X indicates the idle gear I entry direction.

  As shown in FIG. 5A, when the idle gear I is inclined counterclockwise with respect to the primary gear P, the rotation direction A of the primary gear P and the rotation direction of the idle gear I are caused by the inclination. From the time when the specific teeth Pg and Ig of both gears start to come into contact with each other due to the deviation of C, from the primary gear P on the power transmission side to the idle gear I in the contact portion p of both teeth Pg and Ig. A pressing force F acts in the left direction, and the idle gear I moves in the entering direction X by this force F. Accordingly, the idle gear I does not lose its gear at this meshing portion.

  On the other hand, as shown in FIG. 5B, when the secondary gear S is inclined clockwise with respect to the idle gear I, the rotation direction C of the idle gear I and the rotation of the secondary gear S are caused by the inclination. Due to the deviation in the direction B, from the time when the specific teeth Ig and Sg of both gears start to contact until they disengage, at the contact portion q of both teeth Ig and Sg, the idle gear I, which is the power transmission side gear, changes from the secondary gear. A pressing force F acts on the gear S in the right direction, and the idle gear I moves in the counter-entry direction X ′ by the reaction force F ′ of this force.

  Therefore, during the reverse travel as described above, the gear disengagement between the secondary gear S and the idle gear I is disengaged due to the movement of the idle gear I in the counter-engagement direction X ′ caused by the inclination of the reverse gear train. May occur.

  The above phenomenon is shown in FIG. 5B when the rear end portion of the idle gear tooth Ig is in contact with the tooth surface of the primary gear tooth Pg, as shown in FIG. As shown, the same applies to the case where the rear end portion of the tooth Ig of the idle gear is in contact with the tooth surface of the tooth Sg of the secondary gear.

  Further, in FIG. 5, the inclinations of the primary gear P and the idle gear I and the idle gear I and the secondary gear S are exaggerated in order to explain the forces acting on the meshing portions of the gears P, S, and I. ing.

  In order to cope with this problem, in Patent Document 1, as shown in FIG. 6, chamfers Pc ′, Ic ′, Sc are formed on the tooth surfaces of the primary gear P ′, the idle gear I ′, and the secondary gear S ′. Back tapers Pt ′, Pt ′, It ′, It ′, St ′, St ′ that are inclined in a direction in which the tooth thickness decreases from the front end side to the rear end side where “is provided” are the gears P ′, I ′, S It is provided on both tooth surfaces.

  As a result, at the meshing portion between the back taper It ′ and the secondary gear S ′ on the front side in the rotational direction of the idle gear I ′, a component force T in the anti-gear engagement direction acts on the secondary gear S ′ during torque transmission. As a force, a force T ′ in the gear entering direction X acts on the idle gear I ′, and gear disengagement is prevented. Further, at the meshing portion between the primary gear P 'and the idle gear I', a component force T in the gear engagement direction X acts on the idle gear I 'during torque transmission, thereby preventing gear disengagement.

  Accordingly, torque is transmitted through the back tapers Pt ′, It ′, St ′ both in the meshing portion between the primary gear P ′ and the idle gear I ′ and in the meshing portion between the idle gear I ′ and the secondary gear S ′. Any axial portion generates an axial force. The same applies to driving when power is transmitted from the driving force source to the driving wheel side, and also during coasting of the vehicle where inertial force is transmitted from the driving wheel side to the driving source side.

  FIG. 6 schematically shows the meshing state of the primary gear P ′, the secondary gear S ′, and the idle gear I ′ with one figure in order to explain the force acting on the idle gear I ′. Actually, the idle gear I ′ is engaged with the primary gear P ′ and the secondary gear S ′ by separate teeth.

  Further, the X direction shown in the figure is a direction in which the idle gear I 'meshes with the primary gear P' and the secondary gear S ', and this direction is the entering direction of the idle gear I'.

JP 2002-250410 A

  However, if this back taper is set on both tooth surfaces of each gear of the reverse gear train, gear omission can be suppressed. On the other hand, in the case of a gear ensuring the same number of teeth, the tooth thickness is set to each tooth. It becomes thin on the rear end side and the strength of the teeth is lowered. Further, the back taper tends to cause gear noise due to poor tooth contact.

  Therefore, an object of the present invention is to provide a reverse mechanism for a transmission that can reduce the strength reduction and gear noise of each gear while preventing the reverse idle gear from coming off.

  In order to solve the above-described problems, a reverse mechanism for a transmission according to the present invention is configured as follows.

First, the invention described in claim 1
The reverse primary gear provided on the primary shaft on the drive source side, the reverse secondary gear provided on the secondary shaft on the drive wheel side, and the reverse by sliding on the idle shaft arranged in parallel to the both shafts A reverse mechanism of a transmission having a reverse idle gear that can mesh with a primary gear and a reverse secondary gear,
Of the tooth surfaces on both sides of each tooth in the reverse idle gear, only the tooth surface on one side on which a force that moves in the anti-engagement direction from the reverse primary gear or the reverse secondary gear to the reverse idle gear during driving acts, A back taper is provided on one tooth surface of each tooth of the reverse primary gear or the reverse secondary gear that contacts the tooth surface during transmission.

The invention according to claim 2 is the invention according to claim 1,
Of the reverse primary gear and the reverse secondary gear, the gear whose tooth surface comes into contact with the tooth surface on the other side of the reverse idle gear during driving has no back taper on both tooth surfaces of the tooth. And

The invention according to claim 3 is the invention according to claim 1 or 2,
Of the reverse primary gear and the reverse secondary gear, the gear whose tooth surface comes into contact with the one tooth surface of the reverse idle gear during driving has a back taper on both tooth surfaces of each tooth. It is characterized by.

The invention according to claim 4 is the invention according to claim 1 or 2, wherein
Of the reverse primary gear and the reverse secondary gear, the gear whose tooth surface comes into contact with the one tooth surface of the reverse idle gear during driving is provided with a back taper only on the one tooth surface of each tooth. It is characterized by being.

The invention according to claim 5 is the invention according to claim 1,
Of the reverse primary gear and the reverse secondary gear, a gear whose one tooth surface abuts on the one tooth surface of the reverse idle gear during driving is a reverse secondary gear.

  First, according to the first aspect of the present invention, in the selective sliding type reverse gear train, of the tooth surfaces on both sides of each tooth in the reverse idle gear meshing with the reverse primary gear and the reverse secondary gear, during driving, Only the tooth surface on one side on which the force to move in the direction of removal from the reverse primary gear or reverse secondary gear to the reverse idle gear is applied, and each tooth of the reverse primary gear or reverse secondary gear that comes into contact with this tooth surface during driving. Power is transmitted from the reverse primary gear to the reverse idle gear or from the reverse idle gear to the reverse secondary gear via a tooth surface having a back taper on one tooth surface. The reverse idle gear moves in the direction of withdrawal by the axial force generated by Offset or reduced cell force, so that the idle gear gear disengagement is prevented.

  In that case, for the reverse idle gear, the back taper is provided only on the tooth surface on the side where the force in the pulling direction acts on the tooth surfaces on both sides of each tooth. Compared with the case where a taper is provided, the number of processing steps is reduced, and generation of gear noise due to a decrease in tooth strength of the reverse idle gear and a poor meshing of the teeth is suppressed.

  According to a second aspect of the present invention, the tooth surface of the reverse primary gear and the reverse secondary gear that abuts against the tooth surface of the reverse idle gear that is not provided with a back taper during driving. Since the back taper is not provided on the tooth surfaces on both sides of the tooth, the reduction in the strength of the gear due to the provision of the back taper can be reduced.

  Furthermore, according to the invention of claim 3, of the reverse primary gear and the reverse secondary gear, the tooth surface abuts on the tooth surface on the side where the back taper of the reverse idle gear is provided during driving. By providing a back taper on the tooth surfaces on both sides of each tooth, the gear can be prevented from being pulled out, and a conventional gear structure can be applied as it is.

  According to the fourth aspect of the present invention, one tooth surface of the reverse primary gear and the reverse secondary gear contacts the tooth surface on the side where the back taper of the reverse idle gear is provided during driving. The gear in contact can be provided with a back taper only on the one tooth surface of each tooth, thereby preventing gear loss and reducing the strength of the gear.

  According to the fifth aspect of the present invention, by providing a back taper only on the reverse secondary gear side tooth surface of the reverse idle gear, the same effect as the first aspect of the present invention can be obtained. It is done.

It is an expanded view which shows the basic structure of the transmission which concerns on embodiment of this invention. FIG. 3 is a layout view of a reverse speed gear train as viewed from the shaft end side in the transmission. FIG. 5 is a development view of a state before the reverse idle gear of the reverse gear train is engaged with a reverse primary gear and a reverse secondary gear, as viewed from the center side of the reverse idle gear. It is explanatory drawing which shows typically the meshing state of each gear of the said reverse speed gear train. It is explanatory drawing of the gear omission of the reverse idle gear in the selective sliding-type reverse gear train. It is explanatory drawing of a prior art.

  Hereinafter, embodiments of a reverse mechanism of a transmission according to the present invention will be described.

  A manual transmission 1 according to this embodiment shown in FIG. 1 is a 6-speed forward and 1-reverse manual transmission, and is mounted on, for example, an FF (front engine / front drive) type vehicle. The transmission 1 is disposed in a transmission case 2 in a transmission case 2 (not shown) disposed in parallel with the primary shaft 10 connected to an output shaft of an engine (not shown) via a clutch, and the primary shaft 10. It has a secondary shaft 20 connected via a differential device and an idle shaft 30 arranged in parallel between these two axes.

  Between the primary shaft 10 and the secondary shaft 20, a first-speed gear train G1, a reverse-speed gear train GR, a second-speed gear train G2, a third-speed gear train G3, a fourth-speed gear train G4, and 5 A speed gear train G5 and a 6th gear train G6 are provided.

  The first-speed gear train G1 and the second-speed gear train G2 include primary gears 11 and 12 fixed to the primary shaft 10 and secondary gears 21 and 22 loosely fitted to the secondary shaft 20, respectively. ing. The third gear train G3 to the sixth gear train G6 are respectively composed of primary gears 13 to 16 loosely fitted to the primary shaft 10 and secondary gears 23 to 26 fixed to the secondary shaft 20. It is configured. The gears 11 to 16 and 21 to 26 of the forward 1st to 6th gear trains are always meshed with each other.

Further, between the first-speed secondary gears 21 and 22 for loosely fitting to the secondary shaft 20, between the third-speed and fourth-speed primary gears 13 and 14 loosely fitted to the primary shaft 10, Similarly, between the primary gears 15 and 16 for the 5th speed and the 6th speed loosely fitted to the primary shaft 10, the synchronization device 41 for the 1-2th speed, the synchronization device 42 for the 4th speed, and the 5th to 6th speeds, respectively. Synchronizer 43 is arranged, and by operating the shift lever, the sleeves of these synchronizers slide in the axial direction, and the loosely-fitted gear on the slid side is fixed to primary shaft 10 or secondary shaft 20, and the gear The train is in a power transmission state.

  An output gear 28 is provided at the front end of the secondary shaft 20, and the gear 28 is engaged with a diff ring gear 51 that is an input gear of the differential device 50. 1 output rotation is transmitted to the left and right axles 61 and 62 via the differential device 50.

  Here, both front and rear ends of the primary shaft 10 are rotatably supported by the transmission case 2 via bearings 71 and 72, and both front and rear ends of the secondary shaft 20 are supported by bearings 73 and 74, respectively. The front and rear end portions of the idle shaft 30 are supported by the transmission case so as not to rotate relative to each other.

  On the other hand, the reverse gear train GR includes a reverse primary gear 17 (hereinafter referred to as “primary gear”) fixed to the primary shaft 10 and a reverse secondary gear (hereinafter referred to as “secondary gear”) fixed to the secondary shaft 20. 27) and a reverse idle gear (hereinafter referred to as "idle gear") 37 slidably fitted to the idle shaft 30 in the axial direction.

  Then, the idle gear 37 is slid to the left in FIG. 1 and is slid to the position indicated by the phantom line, whereby the reverse idle gear 37 is engaged with the reverse primary gear 17 and the reverse secondary gear 27, respectively, and the reverse speed gear is used. When the gear train GR is in a power transmission state, the power from the engine side is transmitted from the primary gear 17 to the secondary gear 27 via the idle gear 37 and forwards to the left and right axles 61 and 62 via the differential 50. And it is transmitted by rotation in the opposite direction.

  In this case, the primary gear 17, the secondary gear 27, and the idle gear 37 are arranged as shown in FIG. 2 in the Z direction of FIG. 1, and rotate in the A direction, the B direction, and the C direction, respectively, when retreating.

  Here, the configuration of the teeth of the respective gears 17, 27, and 37 constituting the reverse speed gear train GR will be described with reference to FIG.

  As shown in FIG. 3, the gears 17, 27, and 37 have front tooth surfaces 17 a to 17 a, 27 a to 27 a, 37 a to 37 a, and rear tooth surfaces 17 b to 17 b, 27 b to 27 b in the rotational direction Y. 37b ... 37b.

  At the time of driving to transmit power in the same direction as the rotational direction Y, the teeth 17g ... 17g of the primary gear 17 on the front side in the rotational direction 17a and the teeth 37g ... 37g of the idle gear 37 on the rear side in the rotational direction. The surfaces 37b ... 37b are in contact with each other, and the tooth surfaces 37a ... 37a on the front side of the teeth 37g ... 37g of the idle gear 37 are in contact with the tooth surfaces 27b ... 27b on the rear side of the teeth 27g ... 27g of the secondary gear 27. .

  Further, chamfers 17c... 17c, 27c... 27c, 37c... 37c are provided at the front end portions of the gear teeth 17g... 17g, 27g.

  Then, back tapers 37t, 37t, 27t, 27t are respectively provided on the tooth surfaces 37a ... 37a on the front side in the rotational direction of the idle gear 37 that abuts during driving and the tooth surfaces 27b ... 27b on the rear side in the rotational direction of the secondary gear 27. Is provided. That is, these tooth surfaces 37a... 37a, 27b... 27b are inclined at a predetermined angle in the direction in which the tooth thickness decreases from the front end side to the rear end side of the gears 37 and 27, respectively.

  Next, the operation of the transmission according to this embodiment when reversing will be described.

  First, at the time of reverse selection by the change lever, in the reverse gear train GR, the idle gear 37 slides on the idle shaft 30 in the X direction of FIG. 3, and the idle gear 37 is connected to the primary gear 17 as shown in FIG. The reverse gear 27 is meshed with the secondary gear 27 and the reverse gear train GR is in a power transmission state.

  At this time, the primary shaft 10, the secondary shaft 20, the idle shaft 30 are bent, the bearing portions 71, 72, 73, 74 are rattled, and the ratchet at the fitting portion between the idle gear 37 and the idle shaft 30 is caused. Thus, the gears 17, 27, and 37 are engaged with each other in a state where the gear shaft centers are relatively inclined.

  In this embodiment, as in the case shown in FIG. 5, the idle gear 37 is opposed to the primary gear 17 when viewed along the transmission direction of the power during driving due to the bending of the shaft or the rattling of the bearing portion. In the clockwise direction, the secondary gear 27 is inclined relative to the idle gear 37 in the clockwise direction.

  As a result, in the meshing portion between the idle gear 37 and the secondary gear 27, a force in the pulling direction is generated in the idle gear 37.

  At this time, as shown in FIG. 4, back tapers 37 t and 27 t are provided on the tooth surface 37 a of the idle gear 37 and the tooth surface 27 b of the secondary gear 27 that are in contact with each other at the same time. As an axial force of the generated force, a force in the direction X enters the idle gear 37.

  In the meshing between the idle gear 37 and the secondary gear 27, the contact method between the tooth surface 37 a of the idle gear 37 and the tooth surface 27 b of the secondary gear 27 depends on unit variations or changes in the meshing state during operation. There are two possible ways.

  First, as shown in FIG. 4A, when the corner portion of the chamfer 27c of the secondary gear 27 contacts the tooth surface 37a of the idle gear 37, the back of the idle gear 37 is brought into contact with the secondary gear 27 at the contact portion q. An axial component force G that tries to slide along the taper 37t is generated, and a force in the gear engagement direction X acts on the idle gear 37 as a reaction force G ′ of the component force G through the contact portion q.

  On the other hand, as shown in FIG. 4 (a ′), when the corner portion on the rear end side of the idle gear 37 abuts on the tooth surface 27b of the secondary gear 27, the secondary gear 27 is connected to the idle gear 37 at the abutment portion q. An axial component force G that tries to slide along the back taper 27t is generated, and the idle gear moves in the gear engagement direction X.

  That is, in the above-described two contact methods of the tooth surface 37a of the idle gear 37 and the tooth surface 27b of the secondary gear 27, either the back taper 37t of the idle gear 37 or the back taper 27t of the secondary gear 27 is used. Since the back taper generates a component force, the force in the pulling direction due to the inclination of the shaft center cancels out, and gear slipping is suppressed.

  Further, during coasting, the tooth surface of the idle gear 37 and secondary gear 27 generates a force in the idle gear entering direction X due to the inclination of the shaft center, so that the tooth surface that abuts when the teeth of the idle gear 37 and secondary gear 27 are coasting. The back taper is not provided in 37b and 27a.

  On the other hand, the meshing portion of the primary gear 17 and the idle gear 37 generates a force in the direction X during driving and generates a force in the pulling direction during coasting, but the force transmitted through these gears during coasting is small. As a result, no gear loss occurs.

  As described above, since the back taper is provided only on the tooth surface where the force causing the gear loss is generated, the back taper is provided on both tooth surfaces of the three gears as in the normal reverse mechanism. In comparison, a reduction in the strength of each gear can be reduced, and generation of gear noise due to the provision of a back taper can be suppressed.

  In the present embodiment, since it is not necessary to provide back taper on both tooth surfaces 17a and 17b of the reverse primary gear 17, the teeth of the reverse primary gear 17 having the smallest diameter among the gears of the reverse gear train are provided. Strength can be improved.

  Furthermore, in this invention, if there exists the existing gear by which the back taper is provided in the tooth surface of the front side and the back side of the rotation direction of each tooth as a secondary gear, you may use this.

  In the present invention, the shaft center of each shaft may be inclined in the opposite direction to that of the embodiment. In this case, since the gear disengagement force is generated on the primary gear side, the back taper is the rotational direction of the teeth of the primary gear. A back taper is provided on the tooth surface on the front side and the tooth surface on the rear side in the rotational direction of the idle gear. At this time, if there is an existing gear provided with a back taper on the front and rear tooth surfaces in the rotation direction of each tooth, the primary gear may be used.

  Furthermore, the present invention can also be applied to a transmission in which the shaft center is disposed in the entire rear direction of the vehicle. In this case, the input shaft provided with the gear train or the output shaft and the counter shaft of each gear train is provided. The shaft provided with the drive source side gear is the primary shaft, and the shaft provided with the drive wheel side gear is the secondary shaft.

  The present invention can be used in the industrial field of a gear structure applied to a transmission gear mechanism of a transmission mounted on a vehicle.

1 Transmission 10 Primary shaft 17 Reverse primary gear 17a Reverse primary gear rotation direction front tooth surface 17b Reverse primary gear rotation direction rear tooth surface 20 Secondary shaft 27 Reverse secondary gear 27a Reverse secondary gear rotation direction front Tooth surface 27b Tooth surface 27t on the rear side in the rotation direction of the reverse secondary gear Back taper 30 Idle shaft 37 Reverse idle gear 37a Tooth surface 37b on the front side in the rotation direction of the reverse idle gear 37t on the rear side in the rotation direction of the reverse idle gear Back taper X Reverse idle gear engagement direction (meshing direction)
X 'Reverse idle gear reverse direction Y Rotation direction

Claims (5)

The reverse primary gear provided on the primary shaft on the drive source side, the reverse secondary gear provided on the secondary shaft on the drive wheel side, and the reverse by sliding on the idle shaft arranged in parallel to the both shafts A reverse mechanism of a transmission having a reverse idle gear that can mesh with a primary gear and a reverse secondary gear,
Of the tooth surfaces on both sides of each tooth in the reverse idle gear, only the tooth surface on one side on which a force to move in the anti-engagement direction from the reverse primary gear or the reverse secondary gear to the reverse idle gear during driving acts, A reverse mechanism of a transmission, characterized in that a back taper is provided on one tooth surface of each tooth of the reverse primary gear or reverse secondary gear that comes into contact with the tooth surface during transmission.   Of the reverse primary gear and the reverse secondary gear, the gear whose tooth surface comes into contact with the tooth surface on the other side of the reverse idle gear during driving has no back taper on both tooth surfaces of the tooth. The reverse mechanism of the transmission according to claim 1.   Of the reverse primary gear and the reverse secondary gear, the gear whose tooth surface comes into contact with the one tooth surface of the reverse idle gear during driving has a back taper on both tooth surfaces of each tooth. The reverse mechanism of the transmission according to claim 1 or 2, characterized in that.   Of the reverse primary gear and the reverse secondary gear, the gear whose tooth surface comes into contact with the one tooth surface of the reverse idle gear during driving is provided with a back taper only on the one tooth surface of each tooth. The reverse mechanism of the transmission according to claim 1 or 2, wherein the reverse mechanism is provided.   2. The gear of the reverse primary gear and the reverse secondary gear, wherein one tooth surface abuts against the one tooth surface of the reverse idle gear during driving is a reverse secondary gear. The reverse mechanism of the described transmission.

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