JPH08178015A - Continuously variable transmission - Google Patents

Abstract

PURPOSE: To provide a continuously variable transmission facilitating the centering work when an output shaft and an input shaft must be arranged on the same axis, made compact in the axial direction, and capable of simplifying the transmission system of a drive device. CONSTITUTION: The input shaft 10 of a hydrostatic continuously variable transmission 3 protruded outward on one side of a case 2 and the output shaft 31 of reduction gears 4 protruded outward on the other side of the case 2 are located on the same axis.

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 in a power transmission system of a power snowplow, a power lawn mower or the like.

[0002]

2. Description of the Related Art Conventionally, two devices are separated from each other by a substrate.
Case having two chambers, a hydraulic pump and a hydraulic motor are connected via a closed hydraulic circuit, and a hydrostatic continuously variable transmission housed in one chamber of the case, and the other chamber of the case A continuously variable transmission composed of a gear reducer housed in a vehicle is disclosed in Japanese Unexamined Patent Publication No. 1-288663 and Japanese Utility Model Publication No.
It is disclosed in Japanese Patent No. 38202.

[0003]

However, in the above-mentioned conventional device, the output shaft of the gear reducer and the input shaft of the hydrostatic continuously variable transmission are not located on the same axis, and therefore, the output is reduced. There is a problem that it is difficult to perform centering work when it is necessary to arrange the shaft and the input shaft on the same axis, and it is difficult to achieve compactness in the axial direction.

The present invention has been made in view of the above problems of the above-mentioned prior art, and the object thereof is to arrange the output shaft and the input shaft on the same axis. An object of the present invention is to provide a continuously variable transmission that can be easily centered and can be made compact in the axial direction.

[0005]

In order to achieve the above object, a continuously variable transmission according to the present invention has a case having two chambers separated from each other via a substrate which constitutes an oil circuit of a hydraulic pump and a hydraulic motor. And a hydraulic pump and a hydraulic motor connected via a hydraulic closed circuit, and a hydrostatic continuously variable transmission housed in one chamber of the case, and a deceleration housed in the other chamber of the case. An input shaft of the hydrostatic continuously variable transmission, and an output shaft of the speed reducer having the same shaft as the input shaft of the hydrostatic continuously variable transmission. It is characterized in that it is located on the line and is projected to the outside of the other side of the case.

[0006]

The input shaft of the hydrostatic continuously variable transmission projecting outward on one side of the case and the output shaft of the speed reducer projecting outward on the other side of the case are located on the same axis. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. 1 is a side view showing the configuration of a continuously variable transmission according to an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA of FIG. 1, and FIG. 3 is a line BB of FIG. FIG. FIG.
Further, in FIG. 2, reference numeral 1 denotes a continuously variable transmission, which includes a case 2, a hydrostatic continuously variable transmission 3, and a gear reducer 4. Case 2
Has two chambers 6 and 7 separated from each other via a substrate 5, in which one chamber 6 is a hydrostatic continuously variable transmission 3 and the other chamber 7 is a gear reducer 4. It is housed.
The hydrostatic continuously variable transmission 3 has a swash plate type hydraulic pump 8 and a swash plate type hydraulic motor 9. The gear reducer 4
Instead of this, a speed reducer via a chain and a sprocket may be used.

The hydraulic pump 8 includes a pump shaft (input shaft) 10
, Cylinder block 11, and a plurality of pistons 12
And a pump swash plate 13. The pump shaft 10 is
One end thereof is rotatably supported by a bearing portion provided on one side surface of the case 2, and the other end thereof is rotatably supported by a bearing portion provided on the substrate 5. One end of the pump shaft 10 projects outward from one side surface of the case 2, and the other end projects outward from a surface of the substrate 5 on the other chamber 7 side. The cylinder block 11 has a center hole fitted integrally rotatably to the outer periphery of the pump shaft 10 by spline engagement and one end surface slidably attached to one side surface of the substrate 5. Each piston 12
Is slidably fitted in a cylinder hole provided in the cylinder block 11. The pump swash plate 13 is tiltably supported by the case 2 via a trunnion shaft (not shown). The hydraulic pump 8 is a variable displacement pump whose displacement stroke is changed by changing the inclination angle of the pump swash plate 13 by operating an operation lever (not shown) fixed to the trunnion shaft, thereby changing the displacement. It is composed of molds.

The hydraulic motor 9 has a motor shaft 14, a cylinder block 15, a plurality of pistons 16 and a motor swash plate 17. One end of the motor shaft 14 is rotatably supported by a bearing portion provided on one side surface of the case 2, and the other end thereof is rotatably supported by a bearing portion provided on the substrate 5. One end of the motor shaft 14 does not project outward from one side surface of the case 2, and the other end projects outward from the surface of the substrate 5 on the other chamber 7 side. Cylinder block 1
5, a center hole is fitted to the outer periphery of the motor shaft 14 by spline engagement so as to be integrally rotatable, and one end surface is slidably attached to one side surface of the substrate 5. Each piston 16 is slidably fitted in a cylinder hole provided in the cylinder block 15. The motor swash plate 17 is supported by the case 2 in a tilted state by a predetermined angle. The hydraulic motor 9 is of a constant displacement type in which each piston 12 moves by a constant stroke by the action of the motor swash plate 17.

As shown in FIG. 3, the hydraulic pump 8 and the hydraulic motor 9 communicate with each other via a high pressure oil passage 18 and a low pressure oil passage 19 formed in the base plate 5. Therefore, when the pump shaft 10 of the hydraulic pump 8 is rotationally driven, the pressure oil discharged from the hydraulic pump 8 is guided to the hydraulic motor 9 by the high pressure oil passage 18 and rotationally drives the motor shaft 14 of the hydraulic motor 9. . The pressure oil that has finished rotating the motor shaft 14 in this way is released to the low-pressure oil passage 19, and then the hydraulic pump 8
Inhaled into. By the way, the pump shaft 10 and the motor shaft 14
Since the gear ratio between the hydraulic pump 8 and the hydraulic pump 8 is determined by the capacity ratio of the hydraulic pump 8 and the hydraulic motor 9, the speed ratio can be controlled by increasing or decreasing the capacity of the hydraulic pump 8 as described above. .

The substrate 5 has a high-pressure oil passage 18 and a low-pressure oil passage 19
Sliding type neutral valve 20 between and (see FIG. 3)
Is provided and when the neutral valve 20 is operated to the open position, the high pressure oil passage 18 and the low pressure oil passage 19 are short-circuited and the hydraulic motor 9 can be deactivated. Further, when the neutral valve 20 is returned to the closed position, the short circuit between the high pressure oil passage 18 and the low pressure oil passage 19 is prevented, and the operation of the hydraulic motor 9 can be restarted.

Further, as shown in FIG. 2, a pump housing 21 facing the other chamber 7 is fixed to the other side surface of the substrate 5 (the surface on the side of the other chamber 7). A charge pump 22 is provided in the pump housing 21. The charge pump 22 is integrally rotatably fixed to the other end of the pump shaft 10. An oil filter 24 is attached to the suction port 23 of the pump housing 21, and the oil filter 24 is immersed in the lubricating oil filling the other chamber 7. The discharge port 25 of the charge pump 22 is connected to the high pressure oil passage 18 and the low pressure oil passage 19 via the check valves 26 and 27 (see FIG. 3). Further, the discharge port 25 is communicated with the other chamber 7 via a relief valve 28 (see FIG. 2).

Therefore, when the charge pump 22 is driven by the pump shaft 10, the lubricating oil in the other chamber 7 is filtered by the oil filter 24, sucked from the suction port 23 and discharged to the discharge port 25. When the discharge pressure rises above a predetermined value, the relief valve 28 opens and the excess pressure is released into the other chamber 7. On the other hand, when the pressure in the high-pressure oil passage 18 or the low-pressure oil passage 19 becomes lower than the discharge pressure of the charge pump 22 due to oil leakage from the hydraulic pump 8 or the hydraulic motor 9, the check valve 26 or 27 opens. Oil is replenished from the discharge port 25 to the high pressure oil passage 18 or the low pressure oil passage 19.

The gear reducer 4 has a large diameter gear 29 and a small diameter gear 30 which mesh with each other. The large diameter gear 29 is integrally rotatably fitted to the output shaft 31 by spline engagement. The output shaft 31 is disposed on the same axis as the pump shaft 10 that is the input shaft in both the side view and the plan view. The output shaft 31 has one end rotatably supported by a bearing portion provided on the pump housing 21 and the other end side rotatably supported by a bearing portion provided on the other end surface of the case 2. The other end of the output shaft 31 projects outward from the other end surface of the case 2. The small-diameter gear 30 is integrally rotatably fitted to the other end of the motor shaft 14 by spline engagement.

The rotation of the motor shaft 14 is performed by the small diameter gear 3
The speed is reduced by 0 and the large diameter gear 29 and transmitted to the output shaft 31.

In FIG. 2, 32 is an oil inlet for injecting lubricating oil into the other chamber 7, and 33 is a drain outlet for discharging the drain in the other chamber 7.

The continuously variable transmission 1 of the present invention constructed as described above is used by being incorporated in a power transmission system of a power lawnmower as shown in FIG. 4, for example. That is, the pump shaft 10 which is the input shaft of the continuously variable transmission 1 is connected to the drive shaft of the engine 34 of the power lawn mower, and the output shaft 31 of the continuously variable transmission 1 is connected to the drive wheels 35 of the power lawn mower. It connects through 36.

In this state, the power of the engine 34 is transmitted to the pump shaft 10 to drive the hydraulic pump 8, and the hydraulic oil discharged from the hydraulic pump 8 drives the hydraulic motor 9 to rotate the motor shaft 14. Is reduced by the small diameter gear 30 and the large diameter gear 29 and transmitted to the output shaft 31, and further,
It is transmitted to the drive wheels 35 via the power distributor 36, and the drive wheels 35 rotate. In this way, the continuously variable transmission is attached to the space between the engine 34 and the power distributor 36 provided on the side part to simplify the transmission system of the drive device and effectively utilize the space. Is characterized by.

As shown in FIG. 5, the other end 14a of the motor shaft 14 may be projected outward from the other side surface of the case 2 so that the motor shaft 14 can be used as an output shaft. 5, the same parts as those in FIG. 2 are designated by the same reference numerals.

The continuously variable transmission of the present invention is used not only in the power transmission system of a power lawnmower as described above, but also in the power transmission system of a power snowplow and various other power working machines. It goes without saying that it can be used.

[0021]

As described in detail above, according to the continuously variable transmission of the present invention, the input shaft of the hydrostatic continuously variable transmission projecting outwardly on one side of the case and the outwardly projecting side of the case on the other side. Since the output shaft of the speed reducer to be positioned is on the same axis line as each other, centering work is easy when the output shaft and the input shaft need to be arranged on the same axis line, and at the same time with respect to the axial direction. It is possible to achieve compactness and simplification of the transmission system of the drive device.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of a continuously variable transmission according to an embodiment of the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

3 is a cross-sectional view taken along the line BB of FIG.

FIG. 4 is a perspective view of a power lawnmower equipped with the continuously variable transmission of FIG.

FIG. 5 is a diagram of a continuously variable transmission according to another embodiment of the present invention.
FIG.

[Explanation of symbols] 1 continuously variable transmission 2 case 3 hydrostatic continuously variable transmission 4 gear reducer 5 substrate 6 one chamber 7 the other chamber 8 hydraulic pump 9 hydraulic motor 10 pump shaft (input shaft) 31 output shaft

Claims (1)

[Claims] 1. A case having two chambers separated from each other by a substrate forming an oil circuit of a hydraulic pump and a hydraulic motor, the hydraulic pump and the hydraulic motor are connected via a closed hydraulic circuit, and A static hydraulic continuously variable transmission housed in one chamber of the case and a speed reducer accommodated in the other chamber of the case, and the input shaft of the static hydraulic continuously variable transmission is The output shaft of the speed reducer is located on the same axis as the input shaft of the hydrostatic stepless transmission, and the output shaft of the speed reducer is projected outside the other side of the case. Continuously variable transmission.