JPH11230308A - Hydro-mechanical transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lower the power loss of a power transmitting mechanism by providing a lockup clutch mechanism for connecting and disconnecting an annular shaft and an intermediate shaft to/from each other. SOLUTION: A carrier 54 for holding plural epicyclic gears 48 of a third epicyclic gear mechanism 15 and a cylindrical member 52 are directly connected to each other. A lockup clutch mechanism 30 for connecting and disconnecting a second clutch mechanism 11 and an annular shaft 50 to/from each other is provided. A clutch drum 30b is provided in the second clutch mechanism 11 at a part of a hub 11a, and a hub 30 is provided in the annular shaft 50. With this structure, at the time of normal operation mode, gear shift is realized by operating only one clutch mechanism, and at the lockup operating point at a shifting point for each mode, lockup is realized by connecting a high-speed side and a low-speed side clutches, and at the lockup operating point at the highest speed, lockup is realized by engaging only a fourth clutch mechanism and the lockup clutch mechanism 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuously variable transmission used for buses, trucks, various construction machines, various industrial machines, etc., and more particularly to a continuously variable transmission called a hydromechanical transmission.

[0002]

BACKGROUND ART Hydromechanical transmissions include a mechanical transmission having a clutch mechanism and a planetary gear mechanism in a power transmission path connecting an input shaft and an output shaft, and a hydrostatic transmission having a hydraulic pump and a hydraulic motor. Are arranged side by side to continuously change the speed.

FIG. 5 is a schematic diagram of a hydromechanical transmission disclosed in Japanese Patent Application No. 8-54434 filed on Mar. 12, 1996 by the same applicant as the present application, and FIG. FIG. 7 is a diagram showing the change of the speed change mode and the rotation speed and the swash plate angle of the stages, and FIG. 7 is a diagram showing the relationship between the shift mode of the four stages and the connection and disconnection of each clutch mechanism.

The hydromechanical transmission disclosed in this prior application has been changed from a conventional three-stage shift mode to a four-stage shift mode to increase the number of lock-up operation points. Referring to FIG. 5 to FIG.
The schematic configuration and operation of the hydromechanical transmission disclosed in Japanese Patent No. 54434 will be described below.

[0005] In the hydromechanical transmission, a mechanical transmission 3 and a hydrostatic transmission 4 are juxtaposed in a power transmission path connecting an input shaft 1 and an output shaft 2.

The mechanical transmission 3 has a first
A planetary gear mechanism 7, a second planetary gear mechanism 8, a third planetary gear mechanism 15, a first clutch mechanism 10, a second clutch mechanism 11, a third clutch mechanism 12, a drum clutch mechanism 13, And a four-clutch mechanism 14.

The first planetary gear mechanism 7 includes a sun gear 16,
The planetary gear 3 that revolves around the sun gear 16
9, an internal gear 40 meshing with the planetary gear 39, and a carrier 41 holding a plurality of planetary gears 39.

The second planetary gear mechanism 8 includes a sun gear 44 fixed to an intermediate shaft 46, a plurality of planetary gears 43 that revolve by meshing with the sun gear 44, and an internal gear 42 meshing with the planetary gear 43. , A carrier 45 for holding a plurality of planetary gears 43. The carrier 45 and the internal gear 40 of the first planetary gear mechanism 7 are fixed. As shown, the carrier 45 and the output shaft 2 are fixed. The carrier 41 of the first planetary gear mechanism 7 and the internal gear 42 of the second planetary gear mechanism 8 are fixed.

The third planetary gear mechanism 15 includes a sun gear 47 fixed to the input shaft 1, a plurality of planetary gears 48 that revolve and mesh with the sun gear 47, and an internal gear 49 that meshes with the planetary gears 48. Have. The internal gear 49 is fixed to the non-rotating part 53.

The first clutch mechanism 10 includes a connection between an annular shaft 50 fixed to the carrier 41 of the first planetary gear mechanism 7 and the internal gear 42 of the second planetary gear mechanism 8 and a non-rotating portion 51. It is to separate.

The second clutch mechanism 11 connects and disconnects between the cylindrical shaft 52 and the intermediate shaft 46.

The third clutch mechanism 12 performs connection and disconnection between the cylindrical shaft 52 and the annular shaft 50.

The drum clutch mechanism 13 includes a carrier 54 for holding a plurality of planet gears 48 of the third planetary gear mechanism 15.
And disconnection from and to the cylindrical shaft 52.

The fourth clutch mechanism 14 connects and disconnects the input shaft 1 and the intermediate shaft 46.

The hydrostatic transmission 4 has a hydraulic pump 5 and a hydraulic motor 6. The rotation of the input shaft 1 is transmitted to the pump shaft 37 of the hydraulic pump 5 via the gear 35 and the gear 36. The swash plate angle of the swash plate 5a of the hydraulic pump is variable. On the other hand, the hydraulic motor 6
The swash plate angle of the swash plate 6a can be switched in two stages.

The output of the hydraulic motor 6 is transmitted to the sun gear 16 of the first planetary gear mechanism 7 of the mechanical transmission 3 via the motor shaft 38, the gear 18 and the gear 17.

FIGS. 6 and 7 are diagrams for explaining the operation states of the respective parts in the four-stage shift mode. FIG.
The operation of the hydrostatic transmission will be described with reference to FIG.

In the first mode in the low speed range, the first clutch mechanism 10 and the drum clutch mechanism 13 are connected. Since the second clutch mechanism 11, the third clutch mechanism 12, and the fourth clutch mechanism 14 are in the disengaged state, the rotation of the input shaft 1 is not transmitted to the annular shaft 50 and the intermediate shaft 46.

Therefore, the output shaft 2 is rotated only by the transmission force from the hydrostatic transmission 4. The reason why the drum clutch mechanism 13 is in the connected state in the first mode is to prepare for switching from the first mode to the second mode, and in the first mode, the drum clutch mechanism 13 is not necessarily in the connected state. You don't have to.

As the angle of the swash plate of the variable swash plate 5a of the hydraulic pump 5 changes, the rotational speed of the sun gear 16 to which the output of the hydrostatic transmission 4 is transmitted also increases or decreases.

In the second mode in the middle / low speed range, the second clutch mechanism 11 and the drum clutch mechanism 13 are connected. With this connection, the rotation of the input shaft 1 is transmitted to the second planetary gear mechanism 8 via the third planetary gear mechanism 15, the cylindrical shaft 52, and the intermediate shaft 46. Therefore, output shaft 2
Is rotated by a combined force of the transmission force from the intermediate shaft 46 via the second planetary gear mechanism 8 and the transmission force from the hydrostatic transmission 4 via the first planetary gear mechanism 7.

In the third mode in the middle / high speed range, the third clutch mechanism 12 and the drum clutch mechanism 13 are connected. The rotation of the input shaft 1 is transmitted to the carrier 41 of the first planetary gear mechanism 7 via the third planetary gear mechanism 15, the cylindrical shaft 52, and the annular shaft 50. Thus, the output shaft 2 is
The planetary gear mechanism 7 is rotated by a combined force of the transmission force from the annular shaft 50 via the planetary gear 39 and the transmission force from the hydrostatic transmission 4 via the sun gear 16 of the first planetary gear mechanism 7.

In the fourth mode in the high speed range, the fourth clutch mechanism 14 and the third clutch mechanism 12 are connected, and
The first clutch mechanism 10, the second clutch mechanism 11, and the drum clutch mechanism 13 are disengaged. At the intermediate point of the fourth mode, the angle of the swash plate 6a of the hydraulic motor 6 is switched to change the rotation speed of the output shaft 38 of the hydraulic motor 6 with respect to the control amount of the variable swash plate 5a of the hydraulic pump 5. The amount increases. Accordingly, the amount of change in the rotation speed of the output shaft 2 is also increased. The rotation input from the input shaft 1 is transmitted as it is to the sun gear 44 of the second planetary gear mechanism 8 via the fourth clutch mechanism 14 and the intermediate shaft 46. Output shaft 2
Is rotated by the combined force of the transmission force from the carrier 45 of the second planetary gear mechanism 8 and the transmission force from the hydrostatic transmission 4 via the first sun gear 16 of the first planetary gear mechanism 7.

The first mode drum clutch mechanism 1
The connection of the third clutch mechanism 12 in the third and fourth modes is intended to synchronize the rotational speed of the cylindrical shaft 52 at the next switching point, and does not transmit the rotational force.

As shown in FIGS. 6 and 7, when the inclination angle of the variable swash plate 5a is maximum and 0 °,
There are lock-up operating points of

The lock-up operation point is when the variable swash plate 5c is most inclined to the (-) side, and the lock-up operation point is when the variable swash plate 5a is most inclined to the (+) side. The lock-up operation point is an operation point when the variable swash plate 5a is at 0 °.

[0027]

SUMMARY OF THE INVENTION The above mentioned Japanese Patent Application No. 8-54.
The transmission torque applied to each clutch mechanism in each mode in the hydromechanical transmission disclosed in No. 434 will be described with reference to FIG.

First, in the first mode, the first clutch mechanism 10 is connected, and the second clutch mechanism 11,
Since the third clutch mechanism 12 and the fourth clutch mechanism 14 are in the disengaged state, the transmission torque is
It is applied only to the first clutch mechanism 10. It should be noted that the drum clutch mechanism 13 is in the connected state because the purpose is to tune the rotational speed of the cylindrical shaft 52 at the next switching point, and no rotational force is transmitted.

Next, at the lock-up operating point,
First clutch mechanism 10, second clutch mechanism 11 temporarily
And the drum clutch mechanism 13 is connected, and a transmission torque as shown in FIG. 8 is applied to each clutch mechanism.

Next, in the second mode, the second clutch mechanism 11 and the drum clutch mechanism 13 are connected, and a transmission torque as shown in FIG. 8 is applied to each clutch mechanism.

Next, at the lock-up operating point,
Temporarily the second clutch mechanism 11 and the third clutch mechanism 12
8 and the drum clutch mechanism 13 are connected, and FIG.
A transmission torque as shown in FIG.

Next, in the third mode, since the third clutch mechanism 12 and the drum clutch mechanism 13 are connected, transmission torque is applied to each clutch mechanism as shown in FIG.

Next, at the lock-up operating point,
Temporarily the third clutch mechanism 12 and the fourth clutch mechanism 14
Since the drum clutch mechanism 13 is connected, the transmission torque as shown in FIG. 8 is applied to each clutch mechanism.

Next, in the fourth mode, since the fourth clutch mechanism 14 is connected, a transmission torque as shown in FIG. 8 is applied to the fourth clutch mechanism 14. In the fourth mode, the drum clutch mechanism 13 is also in the connected state, but the cylindrical shaft 5 at the next switching point is not connected.
Since the purpose is to tune the rotation speed of 2, the transmission torque is not applied.

Next, at the lock-up operating point,
Since the second clutch mechanism 11, the third clutch mechanism 12, and the fourth clutch mechanism 14 are connected, the transmission torque is applied to each clutch mechanism as shown in FIG.

Here, as described above, in the normal mode position, two clutch mechanisms are respectively connected, and at the lock-up operating point, three clutch mechanisms must be engaged. .
In each of the engaged clutch mechanisms, power loss occurs due to frictional resistance in the seal portion of the operating hydraulic pressure, which becomes a factor of hindering transmission efficiency. Furthermore, in each clutch mechanism, it is necessary to select a larger capacity of the auxiliary hydraulic pump in order to improve hydraulic pressure leakage due to deterioration of the seal ring of the seal portion and responsiveness at the time of starting. This causes a significant reduction in efficiency.

Further, when attention is paid to the drum clutch mechanism 13, the drum clutch mechanism 13 originally engages with the second clutch mechanism 11 and the third clutch mechanism 12 at the lock-up operation point. 52 is provided for the purpose of separating the third planetary gear mechanism 15 from the third planetary gear mechanism 15. However, in the second mode and the third mode, the drum clutch mechanism 13 has a role of transmitting power to the second clutch mechanism 11 and the third clutch mechanism 12. The same transmission torque as in the second clutch mechanism 11 and the third clutch mechanism 12 is applied. As a result, as described with reference to FIG.
In the mode, since a large transmission torque is applied to the third clutch mechanism 12 and the drum clutch mechanism 13, a transmission force that can withstand this transmission torque is required of the drum clutch mechanism 13. For this reason, the outer dimensions of the clutch mechanism and the number of clutch plates also increase, resulting in cost and cost.
There is a problem that causes an increase in weight.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a hydromechanical transmission having a power transmission mechanism capable of reducing power loss.

[0039]

The present invention is based on a hydromechanical transmission in which a mechanical transmission and a hydrostatic transmission are arranged in a power transmission path connecting an input shaft and an output shaft.

In such a hydromechanical transmission, the input shaft side planetary gear mechanism disposed on the input shaft side, the output shaft side planetary gear mechanism disposed on the output shaft side, and the input shaft side planetary gear mechanism are connected. A cylindrical shaft,
An intermediate shaft and an annular shaft connected to the output shaft side planetary gear mechanism, a first clutch mechanism for connecting and disconnecting the annular shaft and the non-rotating portion, and connecting and disconnecting the intermediate shaft and the cylindrical shaft; A second clutch mechanism for performing
It has a third clutch mechanism for connecting and disconnecting the annular shaft and the cylindrical shaft, and a fourth clutch mechanism for connecting and disconnecting the input shaft and the intermediate shaft.

The first aspect of the present invention is characterized in that a lock-up clutch mechanism for connecting and disconnecting the annular shaft and the intermediate shaft is provided.

According to the first aspect of the present invention, in the normal operation mode, only one clutch mechanism needs to be operated. It is only necessary to connect the clutch mechanism that is engaged in each mode on the low speed side, and at the highest speed lock-up operation point, by engaging only the fourth clutch mechanism and the lock-up clutch mechanism,
Each mode and lockup can be realized.

As a result, in all driving ranges,
The number of operating clutch mechanisms can be reduced.
As a result, power loss due to frictional resistance in the seal portion used in the working clutch occurs only during the operation of the clutch mechanism, so that power loss can be reduced, that is, transmission efficiency can be improved.

Further, at the time of starting, the number of clutch mechanisms to be engaged is reduced from two to one, so that it is possible to reduce the time for waiting for the clutch mechanism to be completely engaged.

Further, it is possible to reduce the cost by manufacturing the small and medium clutch drums used for each clutch mechanism from the members of the inner diameter portion of the large clutch drum.
By reducing the number of large clutch drums, it is possible to make this effect more effective and achieve further cost reduction.

Further, claim 2 is a more specific description of the invention described in claim 1. That is, claim 2
In the invention described in (1), the second clutch mechanism has a hub for the second clutch mechanism provided on the intermediate shaft, and the lock-up clutch mechanism has the hub for the lock-up clutch mechanism provided on the annular shaft, and the hub for the second clutch mechanism. Is provided with a clutch drum for a lock-up clutch mechanism.

According to the second aspect of the present invention, it is possible to effectively realize the first aspect of the present invention.

[0048]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the hydromechanical transmission of the present invention will be described below with reference to FIGS.
This will be described with reference to FIG. The same components and mechanisms as those of the hydromechanical transmission described in the background art are denoted by the same reference numerals, and description of the configurations and mechanisms will be omitted.

Therefore, only the features of the present invention will be described below in detail. In the hydromechanical transmission according to the present invention, the carrier 5 holding the plurality of planetary gears 48 of the conventional third planetary gear mechanism 15 is used.
A drum clutch mechanism for connecting and disconnecting the cylindrical member 52 from the cylindrical shaft 52 is eliminated, and the carrier 54 and the cylindrical member 52 are directly connected. Also, the second clutch mechanism 1
A lock-up clutch mechanism 30 for connecting and disconnecting the ring shaft 1 from the ring shaft 50 is newly provided. Specifically, the clutch drum 30b is provided on the hub 11a of the second clutch mechanism 11, and the hub 30a is provided on the annular shaft 50.

Next, the operation of the hydromechanical transmission having the above structure will be described with reference to FIG. First, the connection state of each clutch mechanism in the normal operation mode will be described. In the first mode at low speed,
Only the first clutch mechanism 10 is connected. Since the second clutch mechanism 11, the third clutch mechanism 12, and the fourth clutch mechanism 14 are in the disengaged state, the rotation of the input shaft 1 is not transmitted to the annular shaft 50 and the intermediate shaft 46. Therefore, the output shaft 2 is rotated only by the transmission force from the hydrostatic transmission 4. Here, in order to prepare for switching from the first mode to the second mode, a drum clutch for connecting the carrier 54 and the cylindrical shaft 52 has been provided, but this drum clutch is abolished in the present invention. Since the carrier 54 and the cylindrical shaft 52 are directly connected, there is no need to switch the clutch.

In the second mode in the middle / low speed range, only the second clutch mechanism 11 is connected. With this connection, the rotation of the input shaft 1 is transmitted to the second planetary gear mechanism 8 via the third planetary gear mechanism 15, the cylindrical shaft 52, and the intermediate shaft 46. Therefore, the output shaft 2 is connected to the transmission force from the intermediate shaft 46 via the second planetary gear mechanism 8 and the first planetary gear mechanism 7.
Is rotated by the combined force with the transmission force from the hydrostatic transmission 4 via the.

In the third mode in the middle and high speed range, only the third clutch mechanism 12 is connected. The rotation of input shaft 1 is
The power is transmitted to the carrier 41 of the first planetary gear mechanism 7 via the third planetary gear mechanism 15, the cylindrical shaft 52, and the annular shaft 50.
In this way, the output shaft 2 transmits the transmission force from the annular shaft 50 via the planetary gear 39 of the first planetary gear mechanism 7 and the transmission force from the hydrostatic transmission 4 via the sun gear 16 of the first planetary gear mechanism 7. Is rotated by the combined force of

In the fourth mode in the high speed range, only the fourth clutch mechanism 14 is connected. At the intermediate point of the fourth mode, the angle of the swash plate 6a of the hydraulic motor 6 is switched to change the rotation speed of the output shaft 38 of the hydraulic motor 6 with respect to the control amount of the variable swash plate 5a of the hydraulic pump 5. The amount increases. Accordingly, the amount of change in the rotation speed of the output shaft 2 is also increased.
The rotation input from the input shaft 1 is transmitted as it is to the sun gear 44 of the second planetary gear mechanism 8 via the fourth clutch mechanism 14 and the intermediate shaft 46. The output shaft 2 is rotated by a combined force of a transmission force from the carrier 45 of the second planetary gear mechanism 8 and a transmission force from the hydrostatic transmission 4 via the first sun gear 16 of the first planetary gear mechanism 7. You.

Next, the connection state of each clutch mechanism at the lock-up operation point at the switching point of each mode will be described.

At the lock-up operation point, the first clutch mechanism 10 and the second clutch mechanism 11 are connected.

At the lock-up operation point, the second clutch mechanism 11 and the third clutch mechanism 12 are connected.

At the lock-up operation point, the third clutch mechanism 12 and the fourth clutch mechanism 14 are connected.

At the lock-up operation point, the fourth clutch mechanism 14 and the lock-up clutch mechanism 30 are connected.

This makes it possible to realize lockup at each point.

The transmission torque applied to each clutch mechanism is as shown in FIG. Here, as a result of eliminating the conventional drum clutch, in each normal mode, it is sufficient to operate only one clutch mechanism.
At the lock-up operation point at the mode switching point, it is only necessary to connect the two clutch mechanisms. Further, the newly provided lock-up clutch mechanism 30 is used only at the lock-up operation point, so that it may have a structure that satisfies the strength enough to withstand the transmission torque here, and is compared with the conventional drum clutch. In this case, a small clutch mechanism is sufficient.

Also, in the normal mode, only one clutch mechanism needs to be operated, so that the number of clutch mechanisms to be engaged at the time of starting is reduced from two conventional ones to one. It is possible to reduce the time to wait for completion.

In addition, since the number of operating clutch mechanisms can be reduced from one to two in the past to one or two over the entire operating range, the number of clutch mechanisms in each sealing mechanism can be reduced. Since power loss due to frictional resistance occurs only during operation of the clutch mechanism, power loss can be reduced, that is, transmission efficiency can be improved.

Further, for example, with regard to a clutch conventionally used for a drum clutch, a mode 2 or a mode 3
Although a large number of large clutch plates were used in preparation for large torque transmission in the lock-up clutch mechanism 30,
It is only necessary to use about half the number of middle clutch plates of the drum clutch. As a result, the members of the inner diameter portion of the large clutch plate used in the first clutch mechanism 10, the second clutch mechanism 11, and the third clutch mechanism 12 are moved from the fourth clutch mechanism 14
In addition, a middle clutch plate used for the lock-up clutch mechanism 30 can be manufactured, and the cost can be further reduced.

As described above, the embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

[0065]

According to the hydromechanical transmission according to the present invention, only one clutch mechanism needs to be operated in the normal operation mode, and the lock-up operation point at the switching point of each mode has a high speed. It is only necessary to connect the side and low speed clutch mechanisms, and at the fastest lock-up operating point,
By engaging only the fourth clutch mechanism and the lock-up clutch mechanism, each mode and lock-up can be realized.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure of a hydromechanical transmission according to the present invention.

FIG. 2 is a schematic diagram showing a structure of a hydromechanical transmission according to the present invention.

FIG. 3 is a diagram showing a connection state of each clutch mechanism in each operation mode of the hydromechanical transmission according to the present invention.

FIG. 4 is a diagram showing a transition of torque transmitted to each clutch mechanism in each operation mode of the hydromechanical transmission according to the present invention.

FIG. 5 is a schematic view of a hydromechanical transmission disclosed in Japanese Patent Application No. 8-54434.

FIG. 6 is a diagram showing a relationship between a rotation speed and a change in a swash plate angle in each operation mode of the hydromechanical transmission disclosed in Japanese Patent Application No. 8-54434.

FIG. 7 is a diagram showing a connection state of each clutch mechanism in each operation mode of the hydromechanical transmission disclosed in Japanese Patent Application No. 8-54434.

FIG. 8 is a diagram showing a transition of torque transmitted to each clutch mechanism in each operation mode of the hydromechanical transmission disclosed in Japanese Patent Application No. 8-54434.

[Explanation of symbols]

 Reference Signs List 1 input shaft 2 output shaft 3 mechanical transmission 4 hydrostatic transmission 5 hydraulic pump 5a hydraulic pump swash plate 6 hydraulic motor 10 first clutch mechanism 11 second clutch mechanism 12 third clutch mechanism 13 drum clutch mechanism 14 fourth clutch Mechanism 30 Lock-up clutch mechanism

Claims (2)

[Claims] 1. A hydromechanical transmission in which a mechanical transmission (3) and a hydrostatic transmission (4) are juxtaposed in a power transmission path connecting an input shaft (1) and an output shaft (2), wherein the input shaft is (1) an input shaft side planetary gear mechanism (13) arranged on the side; an output shaft side planetary gear mechanism (7, 8) arranged on the output shaft (2) side; and an input shaft side planetary gear mechanism. (15) a cylindrical shaft (52) connected to the output shaft side planetary gear mechanism (7, 8); an intermediate shaft (46) and an annular shaft (50); and the annular shaft (50). Clutch mechanism (10) for connecting and disconnecting the motor and the non-rotated part (51)
A second clutch mechanism (11) for connecting and disconnecting the intermediate shaft (46) and the cylindrical shaft (52).
And a third clutch mechanism (12) for connecting and disconnecting the annular shaft (50) and the cylindrical shaft (52).
A fourth clutch mechanism (14) for connecting and disconnecting the input shaft (1) and the intermediate shaft (46); connecting and disconnecting the annular shaft (50) to the intermediate shaft (46); A hydromechanical transmission having a lock-up clutch mechanism (30) for performing disconnection. 2. The second clutch mechanism (11) is provided with a second clutch mechanism hub (11a) on the intermediate shaft (46), and the lock-up clutch mechanism (30) is mounted on the intermediate shaft (46). ) Lock-up clutch mechanism hub (30a)
And a clutch drum (30b) for a lock-up clutch mechanism is provided on the second clutch mechanism hub (11a).
The hydromechanical transmission according to claim 1, wherein a transmission is provided.