JP4515875B2 - Assembly structure of vertical transaxle drive pinion shaft - Google Patents

Description

  The present invention relates to an assembly structure of a drive pinion shaft, and more specifically, the assembly of a drive pinion shaft in a vertical transaxle in which a transmission and a differential device (including a final drive gear) are integrally incorporated in a case. It is related to the attached structure.

  For example, in Patent Documents 1 and 2, in a power unit structure of a vehicle in which a longitudinal transaxle in which a transmission and a front differential device are integrally incorporated in a case is arranged to be connected to an engine, the engine drive transmitted through the transmission is transmitted. An assembly structure of a drive pinion shaft that transmits force to a front differential device via a final gear is disclosed.

  First, in the assembly structure of the drive pinion shaft described in Patent Document 1, as shown in FIG. 3, the drive pinion shaft 1 includes a pair of front and rear taper roller bearings 2 and 3 separated in the axial direction. The case (clutch housing) 4 is assembled in a state of being rotatably supported by a small diameter cylindrical portion 5 formed integrally with the lower portion of the case (clutch housing) 4. Then, when the case of the drive pinion shaft 1 is assembled, a preload is applied to both the tapered roller bearings 2 and 3 by adjusting the tightening torque of the nut 6 screwed to the end of the shaft, whereby the drive pinion shaft The assembly rigidity of 1 is ensured to reduce the meshing tooth contact and gap between the hypoid gear 7, that is, the pinion gear 7A and the ring gear 7B.

  Next, in the drive pinion shaft assembly structure described in Patent Document 2, as shown in FIG. 4, the drive pinion shaft 1 includes a pair of double-row tapered roller bearings 2 integrated by an outer race 8. , 3 is rotatably supported by the lower part of the case 4. When the drive pinion shaft 1 is assembled, a preload is applied to the double-row tapered roller bearings 2 and 3 by adjusting the tightening torque of the nut 6 screwed into the shaft end.

  However, in the above-described conventional drive pinion shaft assembly structure, both the front and rear persons perform adjustment work for applying preload to the bearings 2 and 3 when the drive pinion shaft 1 is directly assembled to the case 4. There was a problem that it took assembling man-hours.

  Further, in the former assembly structure of the drive pinion shaft, the inner races 2a, 3a of the two tapered roller bearings 2, 3 are used for preloading the two tapered roller bearings 2, 3 that support the drive pinion shaft 1. A cylindrical spacer 9 is interposed therebetween, and a small-diameter cylindrical portion 5 is connected between the outer races 2b and 3b. For this reason, it is difficult to further reduce the diameter of the small diameter cylindrical portion 5 of the drive pinion shaft 1, and there is a limit to disposing the steering gear box 10 and the cross member 11 closer to the lower side of the drive pinion shaft 1.

  On the other hand, in the latter assembly structure of the drive pinion shaft, a mounting flange 4a for mounting the outer race 8 is integrally formed on the radial case 4 of the double row tapered roller bearings 2 and 3. . For this reason, it is difficult to reduce the diameter of the case of the support portion of the drive pinion shaft 1, and there is a problem that it is difficult to dispose vehicle body parts such as a steering gear box and a cross member below the drive pinion shaft 1.

Japanese Utility Model Publication No. 07-117499 JP 07-186747 A

  Therefore, the present invention has been made to solve the above-described problems of the prior art, and can increase the bearing support rigidity of the drive pinion shaft and improve the assembly workability of the drive pinion shaft. An object of the present invention is to provide an assembly structure of a drive pinion shaft of a vertical transaxle that is excellent and that can sufficiently secure an arrangement space for a steering gear box or the like below the drive pinion shaft.

In order to achieve the above object, an invention according to claim 1 is provided in a longitudinal transaxle in which a transmission and a differential device are incorporated in one case, and an engine driving force transmitted through the transmission is transmitted to the differential device. In the assembly structure of the drive pinion shaft of the vertical transaxle that transmits,
The drive pinion shaft is assembled to the case in a state of being rotatably supported by an iron bearing support member via a pair of bearing members that are spaced apart in the axial direction, and the pair of bearing members Is characterized in that a preload is applied when assembled to the bearing support member together with the drive pinion shaft.

  In order to achieve the above object, in addition to the configuration of the invention described in claim 1, the invention described in claim 2 is configured such that the bearing support member is formed in a constricted shape between the pair of bearing members, It is assembled to the case so as to form a lower part of the case between the transmission and the differential device.

  In order to achieve the above object, in the invention described in claim 3, in addition to the configuration of the invention described in claim 2, the drive pinion shaft is formed such that the shaft portion between the pair of bearing members is reduced in diameter. In addition, the lower side of the bearing support member is formed in a constricted shape in accordance with the reduced diameter shape of the drive pinion shaft.

  In order to achieve the above object, the invention according to claim 4 provides the bearing support in addition to the configuration of the invention according to claim 1 in a state where a belt type continuously variable transmission is used in the transmission. The member is characterized in that the output pulley shaft of the belt type continuously variable transmission is supported via a bearing member.

  According to the first aspect of the present invention, the bearing support member that rotatably supports the drive pinion shaft via the pair of bearing members is made of iron, and the pair of bearing members are bearing supported together with the drive pinion shaft. When assembled to the member, preload is applied without using a cylindrical spacer. As a result, the support rigidity of the drive pinion shaft can be increased, the bearing support member can be reduced in diameter, and the bearing member does not need to be preloaded when the drive pinion shaft is assembled to the case. As a result, it is possible to provide a drive pinion shaft mounting structure with excellent assembly workability.

  According to the second aspect of the present invention, the lower part of the case has a case shape in which the gap between the transmission and the differential device is significantly narrowed. Thus, in addition to the function and effect of the first aspect of the present invention, a sufficient space for disposing the steering gear box and the cross member in the vicinity of the bearing support member, that is, the lower side of the drive pinion shaft, is ensured and the vehicle body is designed. It is possible to provide an assembly structure of a drive pinion shaft capable of increasing the degree of freedom. In addition, in this case, even if the bearing support member having a constricted shape is attached so as to form the lower part of the case, the case rigidity is not impaired.

  According to the third aspect of the present invention, the diameter of the drive pinion shaft between the pair of bearing members is reduced, so that the case shape between the transmission and the differential device is further narrowed. Thus, in addition to the function and effect of the second aspect of the invention, the steering gear box and the cross member can be disposed closer to the lower side of the drive pinion shaft.

  According to the fourth aspect of the present invention, the output pulley shaft of the belt type continuously variable transmission is supported by the bearing support member via the bearing member. Thus, in addition to the function and effect of the invention of the first aspect, the overall length of the longitudinal transaxle can be shortened to achieve compactness, and the shaft load generated on the drive pinion shaft and the shaft generated on the output pulley shaft Since the load can be canceled out with each other, the number of fixing members for attaching and fixing the bearing support member to the case can be reduced.

  The drive pinion shaft is assembled to the case in a state in which the drive pinion shaft is rotatably supported by an iron bearing support member via a pair of bearing members spaced in the axial direction. The pair of bearing members of the bearing support member are formed in a constricted shape, and when the pair of bearing members and the drive pinion shaft are assembled to the bearing support member, preload is applied to the pair of bearing members. As a result, an assembly structure of the drive pinion shaft capable of ensuring high bearing support rigidity, improvement in assembling workability, and sufficient space for arranging the steering gear box or the like is realized.

  An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a skeleton diagram of a power unit structure of a vehicle to which the present invention is applied, and FIG. 2 is an enlarged view of a main part in the same example.

First, a vehicle power unit structure to which the present invention is applied will be described.
As shown in FIG. 1, the power unit structure of the vehicle is arranged such that a vertical transaxle TA that is unitized by incorporating a transmission TM and a differential device DF into one case 100 is connected to the engine 20.

  That is, in the case 100, a torque converter 30 with a lockup that amplifies a driving force (torque) taken out from the rear of the engine 20 via a fluid (automatic transmission fluid) and a forward / backward movement according to a select lever operation (not shown) The forward / reverse switching device 40, the reduction gear device 50 for decelerating and correcting the output rotational speed from the forward / reverse switching device 40, and the ratio of the belt winding diameter by changing the groove width of the pair of input / output pulleys by hydraulic control. A transmission (hereinafter referred to as CVT) 60 in which a belt-type continuously variable transmission that performs continuously variable transmission by changing the speed is used, and a full-time 4WD center differential device that distributes the driving force output from the CVT 60 to the front and rear wheels. (Hereinafter referred to as the center differential) 70 and the driving force transmitted from the CVT 60 via the center differential 70 A drive pinion shaft 80 that passes through the hollow output pulley shaft (hereinafter referred to as a secondary pulley shaft) 62 of the CVT 60 and transmits it to the final gear of the front differential 90, and the driving force transmitted from the drive pinion shaft 80 is transmitted to the left and right front wheels. A front differential 90 (not shown) is disposed.

  The case 100 includes a bell housing 101 containing a torque converter 30 with a lock-up, a forward / reverse switching device 40, a reduction gear device 50, a main case 102 containing a front portion of a drive pinion shaft 80, and a mission case 103 containing a CVT 60. An extension case 104 containing a center differential 70, a transfer case 105 containing a transfer gear 78 for transmitting a driving force from the center differential 70 to a rear differential device (not shown) (not shown), and a final containing a front differential 90. The case 106 is integrally provided.

  The torque converter 30 with lock-up is arranged on an axial center extending straight rearward from the engine 20 together with an input pulley shaft (hereinafter referred to as a primary pulley shaft) 61 of the forward / reverse switching device 40, the reduction gear device 50, and the CVT 60. Has been. The torque converter 30 with lockup includes a drive-side pump impeller 31 connected to the crankshaft 21 of the engine 20, and a driven side connected to the turbine shaft 32 and opposed to the pump impeller 31. Turbine impeller 33, and a stator impeller 34 that rectifies fluid flowing between the pump impeller 31 and the turbine impeller 33. When the pump impeller 31 rotates in the fluid, the turbine impeller 33 rotates, and the driving force output from the engine 20 is amplified and transmitted to the turbine shaft 32. Further, a hydraulic pump 35 that generates hydraulic pressure is connected to the pump impeller 31 via a pump drive shaft 36. When the hydraulic pressure from the hydraulic pump 35 is supplied to the lockup clutch 37, the crankshaft 21 and the turbine shaft 32 are directly connected.

  The forward / reverse switching device 40 uses a double pinion planetary gear, and includes a sun gear 41 fixed to the turbine shaft 32 of the torque converter 30 with lock-up, two pinion gears 42a and 42b meshing with the sun gear 41, and a pinion gear 42b. Is connected to the input shaft 51 of the reduction gear unit 50 and supports the pinion gears 42a and 42b to be rotatable and the reverse brake 44 for rotatably fixing the ring gear 43 to the main case 102 by hydraulic control. The planetary carrier 45 and the forward clutch 46 that fixes the planetary carrier 45 to the turbine shaft 32 by hydraulic control are provided.

  When the select lever is shifted to the D range, hydraulic pressure is supplied to the forward clutch 46 and the planetary carrier 45 is fixed to the turbine shaft 32, whereby the input shaft 51 rotates in the same direction as the rotation direction of the turbine shaft 32. Further, when the select lever is shifted to the R range, the forward clutch 46 is released, and the hydraulic pressure is supplied to the reverse brake 44 so that the ring gear 43 is fixed to the main case 102, thereby causing a direction different from the rotational direction of the turbine shaft 32. The input shaft 51 rotates at the same time.

  The reduction gear device 50 decelerates and corrects the output rotational speed from the forward / reverse switching device 40 to the input rotational speed corresponding to the CVT 60, and includes input / output shafts 51 and 52 arranged on a coaxial core, The counter shaft 53 is arranged in parallel with the output shafts 51 and 52, and the input / output shafts 51 and 52 and two pairs of reduction gear trains including gears 54 to 57 provided on the counter shaft 53 are configured. Yes. The rear end portion of the input shaft 51 is rotatably supported by the output shaft 52 via a needle bearing 58 while being inserted into the hollow output shaft 52. Further, the output shaft 52 is connected to the hollow primary pulley shaft 61 of the CVT 60, so that the output shaft 52 can be regarded as the primary pulley shaft 61. The front end portion of the primary pulley shaft 61 is supported by a bearing retainer 59 that supports the rear end portion of the counter shaft 53 and has an opening 59a that avoids interference with the reduction gear train including the gears 56 and 57. Has been.

  The CVT 60 includes a primary pulley shaft 61 that extends straight behind the engine 20, and a hollow secondary pulley shaft 62 that is parallel to the primary pulley shaft 61 on the lower side of the primary pulley shaft 61. The primary pulley shaft 61 and the secondary pulley shaft 62 are respectively provided with a primary pulley 65 and a secondary pulley 66 whose groove width can be varied by a hydraulic primary cylinder 63 and a secondary cylinder 64, respectively. Then, the winding diameter of the steel belt 67 wound between the pulleys by changing the groove widths of the primary pulley 65 and the secondary pulley 66 by hydraulic control is set to a predetermined gear ratio (for example, 2.50 to 0.50). The driving force thus obtained is transmitted to the secondary pulley shaft 62.

  The center differential 70 is disposed between the secondary pulley 66 and the transfer gear 78 of the CVT 60 and is connected to the secondary pulley shaft 62 via an output clutch 71 capable of variably controlling the fastening force. 72, a pinion gear 73 rotatably supported by the planetary carrier 72, a sun gear 74 fixed to the drive pinion shaft 80 so as to mesh with the pinion gear 73, and a ring gear meshed with the pinion gear 73 and connected to the output shaft 75 76, and a differential limiting clutch 77 that limits the differential between the front and rear wheels by continuously changing the ring gear 76 and the drive pinion shaft 80 from differential-free to differential-lock. The driving force distributed to the output shaft 75 by the center differential 70 is transmitted to the rear drive shaft 79 connected to the rear differential through a transfer gear 78 including a drive gear 78A and a driven gear 78B. The driving force distributed to the drive pinion shaft 80 by the center differential 70 is transmitted to the front differential 90 via the final gear.

Here, the assembly structure of the drive pinion shaft 80 will be described.
As shown in FIGS. 1 and 2, the front portion of the drive pinion shaft 80 is hollow as a bearing support member via a pair of front bearings 81 and a rear bearing 82 that are spaced apart in the axial direction as bearing members. The bearing holder 83 is rotatably supported. The front bearing 81 and the rear bearing 82 are preloaded when they are assembled to the bearing holder 83 together with the drive pinion shaft 80. The bearing holder 83 that supports the drive pinion shaft 80 has a pinion gear 84 that is integrally formed at the shaft front end portion with the shaft rear portion of the drive pinion shaft 80 penetrating into the primary pulley shaft 62 and the final of the front differential 90. In a state of being engaged with a ring gear 91 as a gear, it is assembled and fixed to a lower portion of the main case 102 between the CVT 60 and the front differential 90 by a plurality of fixing bolts 85 as fixing members.

More specifically, the bearing holder 83 is made of iron (for example, cast iron), and the bearing support rigidity is sufficiently secured. The bearing holder 83 includes a first support portion 83a that can be joined to the outer peripheral side and the rear side of the outer race 81a of the front bearing 81, and a first support portion 83a that can be joined to the outer peripheral side and the front side of the outer race 82a of the rear bearing 82. Two support portions 83b are integrally formed. Further, a third support portion 83 c for supporting the front bearing 69 fixed to the front end portion of the secondary pulley shaft 62 by a nut 68 is integrally formed at the rear end portion of the bearing holder 83.
The front bearing 81 and the rear bearing 82 are tapered roller bearings, and the front bearing 69 is a ball bearing.

  Further, the bearing holder 83 is formed in a constricted shape in which the diameter between the first support portion 83a and the second support portion 83b is relatively smaller than the front and rear end portions of the bearing holder 83, The diameter of the support portion of the drive pinion shaft 80 is reduced. In particular, the lower surface side of the constricted portion is deeply constricted so as to be closer to the drive pinion shaft 80 than the upper surface side, and the shaft portion of the drive pinion shaft 80 facing the constricted portion also has a reduced diameter. (See FIG. 2). Annular oil seals 86, 86 are disposed between the confronting surfaces of the bearing holder 83 and the drive pinion shaft 80 at the constricted portion in a state of being separated in the front-rear direction.

Further, the front side of the inner race 81 b of the front bearing 81 is disposed on the rear side of the pinion gear 84 of the drive pinion shaft 80.
Further, at the rear bearing mounting position of the drive pinion shaft 80, the positions of the cotter 87 formed of a split ring for preventing the rear bearing 82 from moving forward of the inner race 82b and the inner race 82b of the rear bearing 82 are set. An adjusting washer A is attached. The drive pinion shaft 80 on the rear surface side of the rear bearing 82 is integrally formed with a male screw portion, and a nut 88 is fastened to the male screw portion. The nut 88 has a caulking portion 88a for fixing to the drive pinion shaft 80 so as not to loosen when the inner race 82b of the rear bearing 82 is tightened from the rear.
Each member described above is assembled to the bearing holder 83 in the order of the drive pinion shaft 80, the front bearing 81, the bearing holder 83, the cotter 87, the washer A, the rear bearing 82, and the nut 88.

  The axial force generated by the tightening torque of the nut 88 acts forward on the inner race 82b of the rear bearing 82 and acts backward on the inner race 81b of the front bearing 81 via the drive pinion shaft 80. To do. Thus, the axial forces in the opposite directions acting on the inner races 81b, 82b of the bearings 81, 82 are received by the bearing holder 83 via the rollers 81c, 82c and the outer races 81a, 82a. In this way, by adjusting the thickness of the washer A and adjusting the tightening of the nut 88, the bearings 81 and 82 are given preloads of approximately the same size, so that the drive pinion is provided via the bearings 81 and 82. The assembly rigidity of the shaft 80 is ensured, and the clearance when the pinion gear 84 is engaged with the ring gear 91 of the front differential 90 is reduced. When the preload application is finished, the caulking portion 88a is caulked to prevent the nut 88 from loosening.

  The drive pinion shaft 80 supported by the bearing holder 83 via both bearings 81 and 82 has a shaft rear portion penetrating the inside of the secondary pulley shaft 62, and a third support portion 83c of the bearing holder 83 is a front bearing. 69, with the front end portion of the secondary pulley shaft 62 supported via 69, and with the pinion gear 84 of the drive pinion shaft 80 engaged with the ring gear 91 of the front differential 90, a plurality of fixing bolts 85 with shims B interposed therebetween. The bearing holder 83 and the main case 102 are assembled and fixed to the lower part. In this assembled state, the bearing holder 83 is arranged and fixed so as to close the opening formed in the lower part of the main case 102 between the CVT 60 and the front differential 90 from the inside of the case, and the lower part of the main case 102 The steering gear box and the cross member can be arranged closer to the lower side of the bearing holder 83. That is, the vertical transaxle TA can be mounted at a lower position with respect to the steering gear box and the cross member, in other words, the steering gear box and the cross member can be arranged at a higher position.

  As described above, according to the present invention, the bearing holder 83 that rotatably supports the drive pinion shaft 80 via the pair of front and rear bearings 81 and 82 is made of iron, and the pair of front and rear bearings. When the bearings 81 and 82 are assembled to the bearing holder 83 together with the drive pinion shaft 80, preload is applied without using a conventional cylindrical spacer. As a result, the support rigidity of the drive pinion shaft 80 can be increased, and the diameter of the bearing holder 83 can be reduced. Further, when the drive pinion shaft 80 is assembled to the main case 102, the front and rear bearings 81 are provided. , 82 can be dispensed with, and a drive pinion shaft mounting structure excellent in assembly workability can be provided.

  Further, according to the present invention, the main case 102 has a case shape in which the space between the CVT 60 and the front differential 90 is significantly narrowed. As a result, the drive pinion shaft can secure a sufficient space for arranging the steering gear box and the cross member in the vicinity of the bearing holder 83, that is, the lower side of the drive pinion shaft 80, and can increase the degree of freedom of vehicle body design. An assembly structure can be provided. In addition, in this case, even if the bearing holder 83 having a constricted shape is attached so as to form the lower part of the main case 102, the case rigidity is not impaired.

  Furthermore, according to the present invention, the shape of the lower part of the main case 102 between the CVT 60 and the front differential 90 is deeper due to the reduced diameter of the drive pinion shaft 80 between the pair of front and rear bearings 81 and 82. . As a result, the steering gear box and the cross member can be arranged closer to the lower side of the drive pinion shaft 80.

  Furthermore, according to the present invention, the secondary pulley shaft 62 of the CVT 60 is supported by the bearing holder 83 via the bearing 69. As a result, the overall length of the longitudinal transaxle TA can be shortened to achieve compactness, and the axial load generated on the drive pinion shaft 80 and the axial load generated on the secondary pulley shaft 62 can be canceled out. The number of fixing bolts 85 for attaching and fixing the holder 83 to the lower part of the main case 102 can be reduced.

  The present invention is not only applied to a vertical transaxle having a CVT, but can also be applied to a vertical transaxle having another type of automatic transmission. Further, the invention is not limited to a full-time 4WD vertical transaxle, but can be applied to a vertical transaxle for a 2WD vehicle.

It is a skeleton figure for demonstrating the powertrain of the vehicle to which this invention was applied. It is an enlarged view of the principal part in the example. It is a skeleton figure for demonstrating the powertrain of the conventional vehicle. FIG. 4 is a skeleton diagram for explaining a power train of a conventional vehicle different from FIG. 3.

Explanation of symbols

TM Transmission DF Differential Equipment TA Vertical Transaxle 60 CVT
62 Secondary pulley shaft (output pulley shaft)
69 Front bearing (bearing member)
80 Drive pinion shaft 81 Front bearing (a pair of bearing members)
82 Rear bearing (a pair of bearing members)
83 Bearing holder (bearing support member)
85 Fixing bolt (fixing member)
90 Front differential (front differential device)
100 case 102 main case

Claims (5)

In an assembly structure of a drive pinion shaft of a vertical transaxle that is provided in a vertical transaxle in which a transmission and a differential device are incorporated in one case, and that transmits the engine driving force transmitted through the transmission to the differential device. ,
The drive pinion shaft is assembled to the case in a state of being rotatably supported by an iron bearing support member via a pair of bearing members that are spaced apart in the axial direction, and the pair of bearing members The assembly structure of the drive pinion shaft of the vertical transaxle is characterized in that a preload is applied when assembled to the bearing support member together with the drive pinion shaft.   The bearing support member is formed in a constricted shape between the pair of bearing members, and is assembled to the case so as to form a lower part of the case between the transmission and the differential device. The assembly structure of the drive pinion shaft of the vertical transaxle according to 1.   The drive pinion shaft has a reduced diameter at the shaft portion between the pair of bearing members, and a lower side of the bearing support member is formed in a constricted shape in accordance with the reduced diameter shape of the drive pinion shaft. The assembly structure of the drive pinion shaft of the vertical transaxle according to claim 2.   In a state where a belt type continuously variable transmission is used in the transmission, the bearing support member supports an output pulley shaft of the belt type continuously variable transmission via a bearing member. The assembly structure of the drive pinion shaft of the vertical transaxle according to Item 1. In a method for assembling a drive pinion shaft of a vertical transaxle that is provided in a vertical transaxle in which a transmission and a differential device are incorporated in a single case, and that transmits an engine driving force transmitted through the transmission to the differential device. ,
After the drive pinion shaft is rotatably assembled to the iron bearing support member via a pair of bearing members that are spaced apart in the axial direction, the bearing support member is assembled to the case. A method of assembling a drive pinion shaft of a longitudinal transaxle, wherein the pair of bearing members is pressurized when assembled to the bearing support member together with the drive pinion shaft.

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