JPH112298A - Belt type continuously variable transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent agitation of transmission oil by a belt transmission mechanism part, to increase oil pan capacity, to increase the outside diameter of a pulley, to increase the degree of freedom of a hydraulic control valve arrangement, and to a provide compact transmission. SOLUTION: A belt type continuously variable transmission is formed such that a torque converter 5 and a forward reverse switching mechanism 10 are disposed in juxtaposition on a first shaft S1, a driven pulley 25 is disposed on a second shaft S3, and a belt 24 is wound between the drive pulley 21 and the driven pulley 25. Further, in this transmission, a second shaft S2 and a third shaft S3 are disposed in a manner to be positioned above the first shaft S1. A hydraulic cylinder 22 for regulating the width of the pulley of the drive pulley 21 is arranged on the engine side and a hydraulic cylinder 26 for regulating the width of the pulley of the driven pulley 25 is arranged on the opposite side to the engine side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a belt-type continuously variable transmission having a belt-type continuously variable transmission mechanism in which a belt is wound between a drive of a variable pulley width and a driven pulley. The present invention relates to a belt-type continuously variable transmission having a torque converter.

[0002]

2. Description of the Related Art Various types of belt-type continuously variable transmissions have been conventionally proposed, and there are various belt-type continuously variable transmissions having a torque converter on an input side.
For example, in Japanese Patent Application Laid-Open No. 5-203014, a torque converter and a drive pulley are arranged in this order on a first shaft (input shaft) connected to an engine output shaft, and are separated from and parallel to the first shaft. A driven pulley is disposed on the extended second shaft, and a forward / reverse switching mechanism including a planetary gear train is disposed on the third shaft that is separated from and extends parallel to the third shaft. A step transmission is disclosed.

In Japanese Patent Application Laid-Open Nos. 5-209665 and 6-221394, a torque converter, a forward / reverse switching mechanism, and a drive pulley are arranged in this order on a first shaft connected to an engine output shaft. There is disclosed a belt-type continuously variable transmission in which a driven pulley is disposed on a second shaft, and the output of the driven pulley is transmitted to a differential mechanism via a power transmission gear train. Japanese Patent Application Laid-Open No. 6-201006 discloses that a torque converter, a drive pulley and a forward / reverse switching mechanism are arranged in this order on a first shaft connected to an engine output shaft, and a driven pulley and a planetary gear are arranged on a second shaft. There is disclosed a belt-type continuously variable transmission in which an auxiliary transmission mechanism is provided, and an output of the auxiliary transmission mechanism is transmitted to a differential mechanism via a power transmission gear train.

[0004]

As described above, belt-type continuously variable transmissions with various types of torque converters are conventionally known, but all of them are connected to an engine output shaft (coaxial with the engine output shaft). The configuration is such that a torque converter, a drive pulley, and a forward / reverse switching mechanism are provided on one shaft (input shaft). Here, when a continuously variable transmission is used for an automobile, the engine output shaft is located at the lower part of the vehicle body, so that the first shaft coaxial with the engine output shaft is also located at the lower part of the vehicle body and is disposed at the lower part of the transmission housing. I have no choice. As a result, the drive pulley is immersed in the transmission oil contained in the transmission housing, and during operation, the drive pulley and the belt agitate the transmission oil, increasing drive loss due to agitation resistance and the like, increasing oil temperature. , And aeration (mixing of air into oil) is likely to occur (especially at low temperatures). There is also a problem that the oil pan capacity is reduced by the volume of the drive pulley immersed in oil.

Furthermore, since the first shaft is located at the lower part of the housing, the outer diameter of the drive pulley is limited to avoid interference with the housing, and it is difficult to increase the outer diameter of the drive pulley to increase the torque capacity. There is a problem. Further, a configuration is generally adopted in which a hydraulic control valve for controlling supply hydraulic pressure for adjusting the pulley width in the drive and driven pulleys is provided at the bottom of the housing, but the first shaft is located at the lower portion of the housing. In addition, since a drive pulley, a forward / reverse switching mechanism, and the like are provided thereon, there is a problem that the arrangement position of the hydraulic control valve is limited because it is necessary to avoid interference with these components. In addition,
As a matter of course, in the configuration in which the torque converter, the forward / reverse switching mechanism, and the drive pulley are arranged side by side on the first shaft, there is a problem that the axial dimension increases.

The present invention has been made in view of such a problem.
The transmission oil can be prevented from being agitated by the belt transmission mechanism, the oil pan capacity can be increased, the outer diameter of the drive pulley can be increased, and the torque capacity can be increased. It is an object of the present invention to provide a belt-type continuously variable transmission that has a high degree of freedom and can have a compact configuration with a short axial dimension.

[0007]

In order to achieve the above object, according to the present invention, a torque converter and a forward / reverse switching mechanism are arranged in parallel on a first shaft (transmission input shaft) connected to a drive source. A second axis extending away from and parallel to the first axis
A drive pulley of a variable pulley width is disposed on the shaft, and the output of the forward / reverse switching mechanism is transmitted to the drive pulley by a power transmission means. On a third shaft extending away from and parallel to the second shaft. And a driven pulley of a variable pulley width, and a belt is wound between the drive pulley and the driven pulley to form a belt-type continuously variable transmission. Furthermore, in this transmission,
A second cylinder and a third axis are disposed on the upper side with respect to the first axis, and a hydraulic cylinder means for variably adjusting a pulley width of the drive pulley is provided on a side of the drive pulley on the side of the drive source, and a driven pulley is provided. Hydraulic cylinder means for variably adjusting the pulley width is provided on the side surface of the driven pulley opposite to the drive source side.

In the case of the belt type continuously variable transmission having such a configuration, only the torque converter and the forward / reverse switching mechanism are provided on the first shaft, and the second and the second shafts are located above the first shaft. Since the drive and the driven pulley having the belt wound around the three shafts are provided, the two pulleys are located at the upper part of the transmission housing, and the transmission oil is not agitated by the pulley and the belt. The axial dimension of the first shaft is shorter than before, and furthermore, only the drive and the driven pulley are provided on the second shaft and the third shaft, respectively. Shorter and more compact.

Further, since the second and third shafts are located above, a relatively large space can be provided below the drives and driven pulleys attached to these shafts.
A large oil pan capacity is obtained, and the degree of freedom of the arrangement position of the hydraulic control valve is increased. Further, since the second and third shafts are located at the upper side, the limitation of the outer diameter of the drive and the driven pulley attached thereto is relaxed, and it is easy to increase the outer diameter to increase the transmission torque capacity. It is.

[0010] Generally, when the transmission is mounted on an FF vehicle with the engine mounted horizontally, the engine output end (engine flywheel portion) is located laterally in the vehicle body width direction. The transmission attached to the end is also located laterally in the vehicle width direction. However, in the FF vehicle, a differential mechanism is provided on the output side of the transmission so that the output is transmitted to the left and right wheels. At this time, when the transmission is located on the side in the vehicle width direction, the differential mechanism is turned off. The left and right axle shafts that transmit power to the left and right wheels have different lengths. The left and right wheels are attached to the vehicle body via a suspension mechanism and move up and down with respect to the vehicle body during traveling, so universal joints are provided on the left and right axle shafts to cope with such vertical movement of the left and right wheels It is supposed to. Here, when the lengths of the left and right axle shafts are different as described above, the intersection angle of the universal joint corresponding to the vertical movement of the wheels is different between the left and right, and there is a problem that imbalance occurs in power transmission to the left and right wheels.

In the case of the belt-type continuously variable transmission according to the present invention, the hydraulic cylinder means for variably adjusting the pulley width of the drive pulley is provided on the side of the drive pulley on the side of the drive source (that is, on the engine side). Hydraulic cylinder means for variably adjusting the pulley width of the pulley is provided on a side surface of the driven pulley opposite to the drive source side. For this reason, a gear train for transmitting power from the driven pulley to the differential mechanism can be located and disposed on the drive source side (engine side) in the transmission housing, and the differential mechanism is also disposed on the drive source side in the transmission housing. It can be set. In this way, the differential mechanism can be disposed as close to the engine as possible in the transmission housing, that is, as close to the center in the vehicle width direction as possible, whereby the difference in the left and right axle shaft lengths can be made as small as possible. It is possible to suppress imbalance in the power transmission of the wheels.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings. First, FIGS. 1 and 2 show a power transmission path configuration for an example of a belt-type continuously variable transmission according to the present invention.
Both figures show one power transmission path configuration in combination. FIG. 3 shows a specific configuration of the transmission. In order to more clearly show the configuration, the configuration is changed to an input portion (FIG. 4), a belt-type continuously variable transmission mechanism portion (FIG. 5), and an output. It is shown divided into side parts (FIG. 6). Further, FIG. 7 shows a positional relationship of each shaft in the transmission housing. FIG. 3 shows the first to fifth axes S1 in FIG.
1 through S5 and a cross section along arrow III-III through the idler axis Si.

The housing 1 of the belt-type continuously variable transmission has a joint surface 2 with an engine flywheel housing at the left end in FIGS. 1 to 6, and the joint surface 2 is joined to the engine flywheel to form a transmission. Is attached to the engine. At this time, the first axis (AXIS) S1 is located coaxially with the engine output shaft Es. In the following description, each rotation center axis of the transmission, such as a rotating shaft and a gear, is shown as a first axis S1 to a fifth axis S5, which means a center axis.

In this belt type continuously variable transmission, a torque converter 5 is mounted on a first shaft S1 in a housing 1.
(Comprising an impeller 5a, a turbine 5b and a stator 5c) and a forward / reverse switching mechanism 10 in parallel. The engine output shaft Es is connected to the impeller 5a of the torque converter 5, and the turbine 5b of the torque converter 5 is connected to the turbine shaft 6 (which is also the input shaft of the forward / reverse switching mechanism 10). The torque converter 5 has a lock-up clutch 5d that can directly connect the engine output shaft Es and the turbine 5b. The forward / reverse switching mechanism 10 has a double pinion type planetary gear, and includes a forward clutch 11 that can directly connect an input / output member (turbine shaft 6 and first shaft 13) and a reverse brake 12 that can fix and hold a ring gear. Prepare.
By selectively operating the clutch 11 and the brake 12, the first shaft 13 (the output shaft of the forward / reverse switching mechanism) rotates forward or backward with respect to the turbine shaft 6 (the input shaft of the forward / reverse switching mechanism). It is possible.

A first gear 16 is connected to the first shaft 13 at the right end on the first shaft S1. The first gear 16 is separated from the first shaft S1 by a predetermined distance. The idler gear 17 meshes with an idler gear 17 rotatably disposed on an idler shaft Si extending in parallel. Further, a second gear 18 is connected to a second shaft 23 rotatably provided on a second shaft S2 extending parallel to the idler shaft Si at a predetermined distance, and the second gear 18 is an idler gear. 17 meshes. Thus, the first gear 16, the idler gear 1
The first and second gears 18 form a first power transmission gear train 15, and rotation of the first shaft 13 is transmitted to the second shaft 23 via the first power transmission gear train 15.

The second shaft 23 has a fixed pulley half 21a integrally formed therewith, and a movable pulley half 21b opposed thereto and arranged movably in the axial direction on the second shaft 23. Drive pulley 21 consisting of
Is disposed on the left side (engine side) of the second gear 18. A third shaft 27 is rotatably disposed on a third shaft S3 extending parallel to the second shaft S2 at a predetermined distance from the second shaft S2, and a fixed pulley half 25a formed integrally with the third shaft 27. A driven pulley 25 is constituted by the movable pulley half 25b which is opposed to the movable pulley and is arranged movably in the axial direction on the third shaft 27.

Drive pulley 21 and driven pulley 25
A metal V-belt 24 is wound therearound to form a belt-type power transmission device 20. The rotation of the drive pulley 21 is transmitted to the driven pulley 25 via the metal V-belt 24. At this time, by moving the movable pulleys 21a and 25a of both pulleys 21 and 25 to adjust the pulley width, the winding radius of the belt between both pulleys 21 and 25 can be arbitrarily adjusted. The speed reduction ratio between 25 can be adjusted steplessly. For such pulley width adjustment (that is, the movable pulley 21a,
A drive-side hydraulic cylinder 22 and a driven-side hydraulic cylinder 26 are provided.

Here, the drive side hydraulic cylinder 22 is disposed on the left side (engine side) of the drive pulley 21, and the driven side hydraulic cylinder 26 is disposed on the right side (opposite side of the engine) of the driven pulley 25. . For this reason,
Most of the components of the transmission can be arranged on the left side (engine side) of the first power transmission gear train 15, so that the amount of the transmission projecting rightward can be kept small, and the axial size of the transmission can be reduced. As short as possible, and the transmission can be made compact.

Left side of driven pulley 25 (engine side)
, A third gear 31 is provided so as to be connected to the third shaft 27. A fourth shaft 34 is rotatably disposed on a fourth shaft S4 extending parallel to the third shaft S3 at a predetermined distance from the third shaft S3. The fourth gear 32 and the fifth gear 33 are integrally formed on the fourth shaft 34. Have been. The third gear 31 meshes with the fourth gear 32. A differential mechanism 36 is disposed on a fifth axis S5 extending parallel to the fourth axis S4 at a predetermined distance from the fourth axis S4.
The sixth gear 35 connected to the sixth gear meshes with the fifth gear 33. Thus, the third to sixth gears 31, 32, 33,
35 constitutes a second power transmission gear train 30;
The rotation of the driven pulley 25 is transmitted to the differential mechanism 36 via the second power transmission gear train 30. The third gear 31 is disposed on the left side (engine side) of the driven pulley 25, and the second power transmission gear train 30 is located on the left side (engine side) in the transmission housing 1.

The left and right axle shafts 37, 38 are connected to the differential mechanism 36, and the power transmitted to the differential mechanism 36 is split here and the left and right wheels (shown in the figure) are passed through the left and right axle shafts 37, 38. ). In this case, since the second power transmission gear train 30 is located on the left side (engine side) in the transmission housing 1 as described above, the differential mechanism 36 is also located on the left side. In this example, a case is shown in which the engine is applied to a front-wheel-drive vehicle equipped with an engine in the vehicle width direction. In this case, the engine flywheel is located on one side in the vehicle width direction (the right side in the drawing), so the transmission is also required. It is located on one side (right side in the figure) in the vehicle width direction. By the way, in this example, the differential mechanism 36 is disposed on the left side (engine side) as much as possible in the transmission housing 1 so as to approach the center in the vehicle width direction as much as possible. Therefore, the difference between the lengths of the left and right axle shafts 37, 38 is as small as possible, and the power transmission efficiency via the left and right axle shafts 37, 38 (the efficiency caused by the difference in the intersection angle of the universal joint) is reduced. The difference is suppressed.

FIG. 7 shows the positional relationship between the first to fifth shafts S1 to S5 and the idler shaft Si in this transmission. As can be clearly understood from this figure, the first shaft S1 and the fifth shaft S5 are located at the lower portion of the transmission housing 1, and the second shaft S2 and the third shaft S3 are located at the upper portion. For this reason, the belt-type power transmission device 20 disposed from the second shaft S2 to the third shaft S3 is located at the upper part in the transmission housing 1 and is above the oil level of the transmission oil put in the housing 1. Located in. As a result, the transmission oil is not agitated by the drive and driven pulleys 21 and 25 and the metal V-belt 24, and the drive oil agitation, the increase in oil temperature, the occurrence of aeration, and the like, which have been conventionally considered as problems, are caused by the agitation of the transmission oil. No problem.

Further, since only the first shaft S1 and the fifth shaft S5 are located at the lower portion of the transmission housing 1 and the belt type power transmission device 20 is disposed above, the belt type power transmission is provided. A relatively large space can be provided below the device 20. Thereby, it is easy to secure a relatively large oil pan capacity. In addition, the degree of freedom of the arrangement position of the hydraulic control valve is increased. For example, the position indicated by a broken line V ′ in FIG. 7 (this is the same position as the conventional position)
Not only that, it can be arranged at the position indicated by the solid line V, and the degree of freedom is high.

Further, the belt-type power transmission device 20 is disposed above the housing 1. The position of the lower surface of the housing 1 is restricted due to the relationship with the minimum ground clearance of the vehicle, but the upper portion is not compared. Subject to few restrictions. For this reason,
It is relatively easy to increase the outer diameters of the drives and driven pulleys 21 and 25 that make up the belt type power transmission device 20 to enable even greater torque transmission.

[0024]

As described above, according to the present invention,
Only the torque converter and the forward / reverse switching mechanism are provided on the first shaft, and a drive and a driven pulley with a belt wound around the second and third shafts located above the first shaft are provided. The two pulleys are located at the upper part of the transmission housing, and the transmission oil is not agitated by the pulleys and the belt, so that the drive loss, the oil temperature rise, and the aeration due to the agitation can be eliminated. The axial dimension of the first shaft is shorter than before, and
Since only the drive and the driven pulley are provided on the second shaft and the third shaft, respectively, the axial size of the entire transmission can be shortened, and the overall configuration can be made compact.

By arranging the drive and the driven pulley on the upper side in this way, a relatively large space can be provided below these, so that a large oil pan capacity can be secured and the hydraulic control valve can be arranged. The degree of freedom of the installation position can be increased. Furthermore, since the upper part of the transmission housing is less strictly limited, the outer diameters of the drive and driven pulleys arranged on the upper part are less restricted, and the outer diameter can be increased to increase the transmission torque capacity. It is.

Further, in the present invention, the hydraulic cylinder means for variably adjusting the pulley width of the drive pulley is provided on the side of the drive pulley on the drive source side (ie, the engine side), and the hydraulic cylinder means for variably adjusting the pulley width of the driven pulley. Since the means is provided on the side of the driven pulley on the side opposite to the drive source side, the gear train for transmitting power from the driven pulley to the differential mechanism (second gear train)
The power transmission gear train) can be disposed on the drive source side (engine side) in the transmission housing, and the differential mechanism can also be disposed on the drive source side in the transmission housing. In this way, the differential mechanism can be disposed as close to the engine as possible in the transmission housing, that is, as close to the center in the vehicle width direction as possible, whereby the difference in the left and right axle shaft lengths can be made as small as possible. It is possible to suppress imbalance in the power transmission of the wheels.

[Brief description of the drawings]

FIG. 1 is a skeleton diagram showing a configuration of a belt-type continuously variable transmission according to the present invention.

FIG. 2 is a skeleton diagram showing a configuration of a belt-type continuously variable transmission according to the present invention.

3 is a cross-sectional view of the configuration of the belt-type continuously variable transmission according to the present invention, which passes through first to fifth shafts and an idler shaft in FIG. 7 and is taken along an arrow III-III.

FIG. 4 is an enlarged sectional view showing a configuration of an input side portion of the transmission shown in FIG. 3;

5 is an enlarged sectional view showing a configuration of a belt-type continuously variable transmission mechanism of the transmission shown in FIG. 3;

FIG. 6 is an enlarged sectional view showing a configuration of an output side portion of the transmission shown in FIG. 3;

FIG. 7 is a schematic side view showing an axial positional relationship of the belt type continuously variable transmission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Transmission housing 5 Torque converter 10 Forward / reverse switching mechanism 15 1st power transmission gear train 20 Belt type power transmission device 21 Drive pulley 24 Metal V belt 25 Driven pulley 30 Second power transmission gear train 36 Differential mechanism

Claims (1)

[Claims] A torque converter disposed on a first shaft connected to a driving source and rotationally driven by receiving a driving force from the driving source; and a torque converter disposed on the first shaft in parallel with the torque converter. A forward / reverse switching mechanism for switching the output rotation direction of the torque converter between forward and reverse; and a variable pulley width type drive pulley disposed on a second shaft extending parallel to the first shaft. A power transmission means for transmitting the output of the forward / reverse switching mechanism to the drive pulley, a driven pulley of a variable pulley width type disposed on a third shaft extending parallel to and spaced from the second shaft; A drive pulley and a belt wound around the driven pulley, wherein the second shaft and the third shaft are disposed above the first shaft, and a pulley width of the drive pulley is Hydraulic cylinder means for changing and adjusting is provided on a side surface of the drive pulley on the side of the drive source, and hydraulic cylinder means for variably adjusting the pulley width of the driven pulley is provided on a side of the driven pulley opposite to the drive source side. A belt-type continuously variable transmission, which is provided on a side surface.