JP2016164419A - Automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic transmission which is made compact in size, and can be improved in vehicle mountability.SOLUTION: In an automatic transmission 1, an input shaft 10, a forward/reverse changeover device 30 which can output the rotation of the input shaft 10 as it is, or can reversely output it, and a primary pulley 21 which inputs the rotation from the forward/reverse changeover device 30 are arranged on a first axis AX1, a secondary pulley 22, a reduction mechanism 40 for decelerating the rotation of the secondary pulley 22, and a differential device 60 which transmits the rotation to two drive shafts 70L, 70R are arranged on a second axis AX2, and the drive shaft 70L passes an internal peripheral side of the secondary pulley 22, and is connected to the differential gear 60. Since the automatic transmission 1 can be constituted of the two axes of the first axis AX1 and the second axis AX2, the transmission can be made compact in size.SELECTED DRAWING: Figure 1

Description

  This technology relates to an automatic transmission mounted on a vehicle or the like, and particularly includes a primary pulley on a first shaft, a secondary pulley on a second shaft, and a continuously variable transmission mechanism having a belt wound around these pulleys. Relates to an automatic transmission.

  There is an automatic transmission mounted on a vehicle or the like that uses a belt-type continuously variable transmission (see Patent Document 1). Generally, in an automatic transmission equipped with a belt-type continuously variable transmission, the rotation of a drive source such as an engine is switched between forward rotation and reverse rotation by a forward / reverse switching device to be a primary pulley of the belt-type continuously variable transmission. It is configured to input, output a speed change rotation from the secondary pulley while continuously changing speed, and reverse the speed change rotation while decelerating by the countershaft and transmit it to the differential device. Therefore, in such an automatic transmission, a forward / reverse switching device and a first shaft on which a primary pulley is disposed, a second shaft on which a secondary pulley is disposed, a third shaft on which a counter shaft is disposed, and a differential device are disposed. There are a total of four axes, the fourth axis.

Japanese Patent Laid-Open No. 2004-211803

  By the way, those having a total of four shafts like the automatic transmission of the above-mentioned Patent Document 1 are difficult to downsize in the direction orthogonal to the axial direction because these four shafts are arranged in parallel, and are mounted on the vehicle. There is a problem that improvement of sex is difficult.

  Also, for example, it is conceivable that the countershaft that performs reversal is omitted by outputting reverse rotation during forward travel by the forward / reverse switching mechanism, so that the countershaft is configured with three axes, but the reduction ratio in the countershaft cannot be obtained. Therefore, it is necessary to achieve a large reduction ratio in the continuously variable transmission, and a large hydraulic pressure is also required to prevent belt slip, resulting in a problem that the driving loss of the oil pump becomes large and it is difficult to improve fuel consumption.

  Accordingly, it is an object of the present invention to provide an automatic transmission that is compact and can be mounted on a vehicle.

The automatic transmission (1) is disposed on the first shaft (AX1) and is input coupled to the drive source (2).
A forward / reverse switching device (30) disposed on the first shaft (AX1) and capable of outputting or reversing the rotation of the input shaft (10) as it is;
A primary pulley (21) that is arranged on the first axis (AX1) and inputs rotation from the forward / reverse switching device (30), and a second axis (AX2) parallel to the first axis (AX1) A continuously variable transmission mechanism (20) having a secondary pulley (22) disposed above and a belt (23) wound around the pulleys;
A speed reduction mechanism (40) disposed on the second shaft (AX2) and configured to decelerate rotation of the secondary pulley (22);
A differential device that is arranged on the second shaft (AX2) and transmits rotation from the speed reduction mechanism (40) to two drive shafts (70L, 70R) that are drivingly connected to the left and right wheels (80L, 80R). (60)
The inner peripheral side of the secondary pulley (22) is configured so that one (70L) of the two drive shafts can be connected to the differential device (60).

  In addition, although the code | symbol in the said parenthesis is for contrast with drawing, this is for convenience for making an understanding of invention easy, and has no influence on the structure of a claim. It is not a thing.

  According to this automatic transmission, since the rotation of the secondary pulley is decelerated by the reduction planetary gear and transmitted to the differential device, it is not necessary to achieve a large reduction ratio with the continuously variable transmission, and fuel consumption can be improved. However, since it can be composed of a total of two axes, the first axis and the second axis, it is possible to reduce the size and improve the vehicle mountability.

The skeleton figure which shows the automatic transmission which concerns on this Embodiment. The engagement table of this automatic transmission.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments according to the present invention will be described below with reference to FIGS.

  First, the schematic structure of the automatic transmission 1 according to the present embodiment will be described with reference to FIG. As shown in FIG. 1, the automatic transmission 1 is drivingly connected to an engine (drive source) 2 via, for example, a torque converter 3 with a lock-up clutch (or a starting device such as a starting clutch). The input shaft 10 is provided on the first shaft AX1. The input shaft 10 is on the first shaft AX1 coaxial with the input shaft 10. In the case 11, the forward / reverse switching device 30 and the belt-type continuously variable transmission mechanism are provided. 20 (hereinafter referred to as “CVT20”) primary pulleys 21 are arranged.

  Further, as shown in FIG. 1, the secondary pulley 22 of the CVT 20, the speed reduction mechanism 40, and the differential device 60 are arranged on the second axis AX <b> 2 parallel to the first axis AX <b> 1, and the differential device 60. Are arranged on the second axis AX2 so as to be driven and connected to the left and right wheels 80L, 80R (an axle shaft) 70L, 70R.

  Next, a detailed configuration of the automatic transmission 1 will be described with reference to FIG. A forward / reverse switching device 30 is arranged on the outer peripheral side of the input shaft 10 on the first axis AX1 on the axial input side. The forward / reverse switching device 30 is roughly configured to include a clutch C-1, a brake B-1, and a double pinion type first planetary gear DP1. The planetary gear DP1 meshes with the first sun gear S1 that is drivingly connected to the input shaft 10 and receives driving rotation from the engine 2, the first ring gear R1 that can be locked by the brake B-1, and the first sun gear S1. The first pinion P1 and the second pinion P2 meshing with the first pinion P1 and the first ring gear R1 are rotatably supported, connected to the clutch C-1 and drivingly connected to the primary pulley 21 of the CVT 20. And a first carrier CR1.

  That is, in the forward / reverse switching device 30, as shown in FIG. 2, when the forward speed is determined by a control unit (not shown) and the clutch C-1 is engaged based on hydraulic control by a hydraulic control device (not shown). As shown in FIG. 1, the input shaft 10 and the first carrier CR1 are engaged. Then, the rotation of the input shaft 10 is input to the first sun gear S1 and the first carrier CR1, and the entire first planetary gear DP1 is in a directly connected rotation state, that is, the forward / reverse switching device 30 outputs the rotation of the input shaft 10 as it is. It is transmitted to the primary pulley 21.

  Further, as shown in FIG. 2, the forward / reverse switching device 30 is determined when the reverse gear is determined by a control unit (not shown) and the brake B-1 is engaged based on hydraulic control by a hydraulic control device (not shown). As shown in FIG. 1, the rotation of the first ring gear R <b> 1 is locked to the case 11. Then, the rotation of the input shaft 10 input to the first sun gear S1 is reversed by the first ring gear R1 to which the rotation is fixed, and the first carrier CR1 rotates in the reverse direction. Is rotated and output to the primary pulley 21.

  On the side opposite to the engine 2 in the axial direction of the input shaft 10 on the first shaft AX1, a fixed sheave 21a of the primary pulley 21 of the CVT 20 is driven and fixed to the carrier CR1. The primary pulley 21 has a fixed sheave 21a and a movable sheave 21b that is movable in the axial direction with respect to the fixed sheave 21a. By the hydraulic pressure of the hydraulic oil chamber disposed on the back surface of the movable sheave 21b, the primary pulley 21 A belt 23 is sandwiched between the fixed sheave 21a and the movable sheave 21b.

  A secondary pulley 22 of the CVT 20 is disposed on the second shaft AX2 so as to face the primary pulley 21. Similar to the primary pulley 21, the secondary pulley 22 has a fixed sheave 22a and a movable sheave 22b that is movable in the axial direction with respect to the fixed sheave 22a, and is disposed on the back surface of the movable sheave 22b. The belt 23 is sandwiched between the fixed sheave 22a and the movable sheave 22b by the oil pressure of the oil chamber.

  Accordingly, the CVT 20 is supplied with a sheave pressure adjusted by a hydraulic control device (not shown) based on a command from a control unit (not shown) to the hydraulic oil chamber on the back of the movable sheaves 21b and 22b, thereby generating a primary pulley. The movable sheave 21b of 21 and the movable sheave 22b of the secondary pulley 22 are controlled in the axial direction, and the contact radius of the belt 23 in the primary pulley 21 and the secondary pulley 22 is freely changed while adjusting the clamping force of the belt 23, and the primary A gear ratio which is a rotation ratio of the secondary pulley 22 with respect to the rotation of the pulley 21 is freely achieved.

  A connecting shaft 25 centered on the second shaft AX2 is fixed to the fixed sheave 22a of the secondary pulley 22 on the second shaft AX2, and the end of the connecting shaft 25 is fixed to the fixed sheave 22a. A single pinion type second planetary gear (deceleration planetary gear) SP constituting the reduction mechanism 40 is drivingly connected. That is, the second planetary gear SP includes a second sun gear S2 that is drivingly connected to the secondary pulley 22 via the connecting shaft 25, a second ring gear R2 that is always fixed to the case 11, the second sun gear S2, and the second sun gear S2. The second pinion P3 meshing with the two-ring gear R2 is rotatably supported, and the second carrier CR2 is drivingly connected to the differential device 60.

  Therefore, the speed reduction mechanism 40 decelerates the rotation of the secondary pulley 22 input to the second sun gear S2 by the second ring gear R2 whose rotation is fixed, and outputs it from the second carrier CR1, that is, the speed of the CVT 20 is reduced. And transmitted to the differential device 60. The speed reduction mechanism 40 is disposed at a position overlapping the first planetary gear DP1 of the forward / reverse switching device 30 in the axial direction when viewed from the radial direction.

  The differential device 60 is configured by a double-pinion type third planetary gear DP2, and is engaged with the third ring gear R3, the third sun gear S3, and the third ring gear R3 that are drivingly connected to the speed reduction mechanism 40. P4 and a third carrier CR3 that rotatably supports the fourth pinion P4 and the fifth pinion P5 meshing with the third sun gear S3. In the third planetary gear DP2 configured in this way, the gear ratio of the third sun gear S3 and the third carrier CR3 to the third ring gear R3 is set to be the same, and the rotation transmitted to the third ring gear R3 is transmitted to the third sun gear. S3 and third carrier CR3 are distributed while absorbing their differential rotation.

  The differential device 60 is disposed at a position overlapping the clutch C-1 of the forward / reverse switching device 30 in the axial direction when viewed from the radial direction. That is, since the clutch C-1 can be configured to have a smaller diameter than the first planetary gear DP1, the first shaft AX1 and the second shaft AX2 are arranged close to each other even if the differential device 60 has a larger diameter. This contributes to making the automatic transmission 1 compact.

  The third carrier CR3 of the differential device 60 is drivingly connected to the spline portion 60RS on the right side when mounted on the vehicle, and the drive shaft connected to the right wheel 80R is connected to the spline portion RS of the differential device 60. (Askle shaft) 70R can be splined. The third sun gear S3 is drivingly connected to the left spline portion 60LS when mounted on the vehicle. The spline portion LS of the differential device 60 has a driving shaft (an axle shaft) connected to the left wheel 80L. 70L (one of the two drive shafts) is on the inner peripheral side (center side) of the secondary pulley 22 of the CVT 20 and can be splined through a through hole formed on the second shaft AX2. . The through hole formed on the center side of the secondary pulley 22 is formed so as to leave a gap with the drive shaft 70L so that the secondary pulley 22 is not affected even if the drive shaft 70L vibrates somewhat. preferable.

  A connecting shaft extending from the third sun gear S3 through the secondary pulley 22 to the outside (left side) of the secondary pulley 22 is provided, and the spline portion LS is arranged outside the secondary pulley 22 to thereby generate vibration from the drive shaft 70L. May be configured to be absorbable by the spline portion LS so that the secondary pulley 22 is less susceptible to vibrations from the wheels 80L.

  Next, the operation of the automatic transmission 1 according to the present embodiment will be described with reference to FIGS. 1 and 2.

  First, in the automatic transmission 1, for example, when the reverse range (R range) is selected and a reverse gear is achieved by a command from a control unit (not shown), the brake B-1 is engaged as shown in FIG. Match. Then, as shown in FIG. 1, the rotation of the input shaft 10 is reversed by the forward / reverse switching device 30, the reverse rotation is transmitted to the primary pulley 21 of the CVT 20, the reverse rotation is output from the secondary pulley 22, and the reverse rotation is further performed. Is decelerated by the deceleration mechanism 40 and transmitted to the differential device 60, and reverse rotation is output to the left and right wheels 80L and 80R. In the reverse speed, the transmission ratio of the CVT 20 is maintained in a fixed state, and the shift control is not performed.

  Next, in the automatic transmission 1, for example, when the drive range (D range) is selected and the forward speed is achieved by a command from a control unit (not shown) based on the vehicle speed, as shown in FIG. Engage -1. Then, as shown in FIG. 1, the forward / reverse switching device 30 outputs the rotation of the input shaft 10 as it is and transmits the forward rotation to the primary pulley 21 of the CVT 20. Then, the axial positions of the movable sheave 21b of the primary pulley 21 and the movable sheave 22b of the secondary pulley 22 of the CVT 20 are hydraulically controlled, and the contact radius of the belt 23 is freely changed according to, for example, the vehicle speed and the accelerator opening. The rotation of the input shaft 10 is changed with a speed ratio range from the maximum speed ratio to the minimum speed ratio. The forward rotation shifted in the forward direction output from the secondary pulley 22 is decelerated by the speed reduction mechanism 40 and transmitted to the differential device 60, and the forward rotation shifted in the forward direction is output to the left and right wheels 80L and 80R. .

<Summary of this embodiment>
The automatic transmission (1) according to the present embodiment described above has an input shaft (10) disposed on the first shaft (AX1) and drivingly connected to the drive source (2),
A forward / reverse switching device (30) disposed on the first shaft (AX1) and capable of outputting or reversing the rotation of the input shaft (10) as it is;
A primary pulley (21) that is arranged on the first axis (AX1) and inputs rotation from the forward / reverse switching device (30), and a second axis (AX2) parallel to the first axis (AX1) A continuously variable transmission mechanism (20) having a secondary pulley (22) disposed above and a belt (23) wound around the pulleys;
A speed reduction mechanism (40) disposed on the second shaft (AX2) and configured to decelerate rotation of the secondary pulley (22);
A differential device that is arranged on the second shaft (AX2) and transmits rotation from the speed reduction mechanism (40) to two drive shafts (70L, 70R) that are drivingly connected to the left and right wheels (80L, 80R). (60)
The inner peripheral side of the secondary pulley (22) is configured so that one (70L) of the two drive shafts can be connected to the differential device (60).

  Thereby, since the rotation of the secondary pulley 22 is decelerated by the second planetary gear SP and transmitted to the differential device 60, it is not necessary to achieve a large reduction ratio in the CVT 20, and fuel consumption can be improved. Since a total of two shafts, the first shaft AX1 and the second shaft AX2, can be configured, the automatic transmission 1 can be made compact, and the vehicle mountability can be improved.

  In the automatic transmission (1) according to the present embodiment, the speed reduction mechanism (40) is fixed to the sun gear (S2) that is drivingly connected to the secondary pulley (22) and the case (11). A reduction planetary gear (SP) having a ring gear (R2) and a carrier (CR2) rotatably supporting a pinion (P3) meshing with the sun gear (S2) and the ring gear (R2). To do.

  As a result, when the rotation of the secondary pulley 22 is decelerated in the second planetary gear SP, for example, compared with the case where a double pinion planetary gear is used, the meshing position can be reduced, transmission loss is reduced, and automatic transmission is performed. It is possible to prevent the transmission efficiency of the machine 1 from being lowered.

<Possibility of other embodiments>
In the automatic transmission 1 according to the above-described embodiment, the forward / reverse switching device 30 outputs the rotation of the input shaft 10 as it is in the forward gear and reversely outputs the rotation of the input shaft 10 in the reverse gear. However, on the contrary, the rotation of the input shaft may be inverted and output at the forward stage, and the rotation of the input shaft may be output as it is at the reverse stage. In this case, the deceleration mechanism 40 is configured to reverse the rotation while decelerating. As a mechanism for reversing the rotation while decelerating in this way, for example, a double pinion planetary gear is used, the rotation of the secondary pulley is input to the sun gear, the ring gear is always fixed to the case, and the reverse rotation that is decelerated from the carrier is output. It is possible. When configured in this way, it is allowed to cause transmission loss due to an increase in meshing locations in a double-pinion type planetary gear at the forward stage, at the time of reversal of rotation in the forward / reverse switching mechanism.

  In the automatic transmission 1 according to the present embodiment, the forward / reverse switching device 30 is configured by the clutch C-1, the brake B-1, and the double pinion planetary gear DP1, but the present invention is not limited thereto. As long as it can output by switching between forward rotation and reverse rotation, any configuration may be used, and further, the speed may be reduced or increased by a forward / reverse switching device.

  In the automatic transmission 1 according to the present embodiment, the reduction mechanism 40 using a single pinion type planetary gear has been described. However, as long as it is arranged on the second shaft and can reduce the rotation speed. Any mechanism may be used.

  In the automatic transmission 1 according to the present embodiment, the differential device 60 using the double pinion planetary gear DP2 has been described. However, the present invention is not limited thereto, and for example, side gears connected to the left and right drive shafts and It may be configured by a pinion gear that connects them, or may be mounted in combination with a so-called limited slip differential that restricts differential rotation on the left and right.

  In the present embodiment, the configuration of the automatic transmission 1 connected to the engine has been described. For example, a motor / generator is disposed between the torque converter on the first shaft and the engine, or instead of the torque converter, The automatic transmission 1 may be configured as a hybrid drive device.

DESCRIPTION OF SYMBOLS 1 ... Automatic transmission 2 ... Drive source (engine)
10 ... Input shaft 11 ... Case 20 ... Continuously variable transmission mechanism (CVT)
DESCRIPTION OF SYMBOLS 21 ... Primary pulley 22 ... Secondary pulley 23 ... Belt 30 ... Forward / reverse switching device 40 ... Deceleration mechanism 60 ... Differential device 70L, 70R ... Drive shaft 80L, 80R ... Wheel AX1 ... First axis AX2 ... Second axis SP ... Deceleration planetary gear (2nd planetary gear)
S2: Sun gear (second sun gear)
CR2 ... carrier (second carrier)
P3 ... Pinion (3rd pinion)
R2 ... Ring gear (second ring gear)

Claims (2)

An input shaft disposed on the first shaft and drivingly coupled to the drive source;
A forward / reverse switching device arranged on the first shaft and capable of directly outputting or inverting the rotation of the input shaft;
A primary pulley that is disposed on the first shaft and inputs rotation from the forward / reverse switching device, a secondary pulley that is disposed on a second shaft parallel to the first shaft, and is wound around the pulleys. A continuously variable transmission mechanism having a belt,
A speed reduction mechanism disposed on the second shaft and configured to decelerate rotation of the secondary pulley;
A differential device that is disposed on the second shaft and transmits rotation from the speed reduction mechanism to two drive shafts that are drivingly connected to the left and right wheels, respectively.
The inner peripheral side of the secondary pulley is configured so that one of the two drive shafts can be connected to the differential device.
An automatic transmission characterized by that. The speed reduction mechanism is a speed reduction planetary gear having a sun gear drivingly connected to the secondary pulley, a ring gear fixed to the case, and a carrier that rotatably supports the sun gear and the pinion engaged with the ring gear. ,
The automatic transmission according to claim 1.

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