JP4251536B2 - transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission with a hydraulic PTO clutch structure.
[0002]
[Prior art]
In a working vehicle such as a mower tractor, a PTO transmission path for taking out the driving force from the driving source to the outside is provided in addition to the traveling transmission path for transmitting the driving force from the driving source to the driving axle.
[0003]
Generally, in the PTO transmission path, a friction plate hydraulic clutch provided between a PTO drive shaft positioned on the drive side and operatively connected to a drive source and a PTO driven shaft positioned on the driven side. A hydraulic PTO clutch structure having a mechanism and a hydraulic brake mechanism interlocking with the hydraulic clutch mechanism is provided (see Patent Document 1).
[0004]
The conventional hydraulic PTO clutch structure is configured such that the hydraulic clutch mechanism and the hydraulic brake mechanism are selectively operated by the action of hydraulic pressure.
That is, when the hydraulic clutch mechanism transmits power from the PTO drive shaft to the PTO driven shaft, the hydraulic brake mechanism does not operate, and the hydraulic clutch mechanism moves from the PTO drive shaft to the PTO driven shaft. When the power transmission is interrupted, the hydraulic brake mechanism operatively applies a braking force to the PTO driven shaft.
[0005]
Further, the conventional hydraulic PTO clutch structure supplies lubricating oil to the hydraulic clutch mechanism and the hydraulic brake mechanism in order to effectively prevent over-wear and damage of friction sliding parts such as friction plates and brake surfaces. However, there is room for improvement in the following points.
[0006]
That is, in the hydraulic PTO clutch structure, the lubricating oil is supplied to the hydraulic clutch mechanism with oil that is scraped as the PTO drive shaft rotates, and the lubricating oil supply to the hydraulic brake mechanism is supplied to the PTO driven shaft. It is done with oil that is scraped with the rotation.
However, during the operation of the hydraulic brake mechanism, the rotation of the PTO driven shaft stops. Therefore, the lubricating oil is not sufficiently supplied at the timing when the lubricating oil is to be supplied most to the friction sliding portion in the hydraulic brake mechanism.
[0007]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-79839
[Problems to be solved by the invention]
The present invention has been made in view of the prior art, and in a transmission having a hydraulic clutch mechanism and a hydraulic brake mechanism interlocking with each other, the lubricating oil is applied to the brake operating surface of the hydraulic brake mechanism when the hydraulic brake mechanism is operated. It is an object to provide a transmission having a simple structure capable of effectively supplying the transmission .
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a transmission including a PTO transmission path that outputs a driving force from a driving source to the outside, and a housing that accommodates the PTO transmission path.
In the transmission according to the present invention, the PTO transmission path is coaxially arranged with the PTO drive shaft operatively connected to the drive source and along the longitudinal direction of the vehicle , and positioned on the driven side. An installed PTO driven shaft, a hydraulic clutch mechanism that selectively transmits and cuts power from the PTO drive shaft to the PTO driven shaft, and the PTO driven shaft in conjunction with the power cut-off operation of the hydraulic clutch mechanism. A hydraulic brake mechanism that operatively applies a braking force.
The hydraulic clutch mechanism includes a drive side cylinder that is supported by the PTO drive shaft so as not to rotate relative to the PTO drive shaft, a drive side friction plate that is supported by the drive side cylinder so as not to rotate relative to the shaft, and is slidable in the axial direction, and the PTO driven A driven cylinder supported on the shaft so as not to rotate relative to the shaft; a driven friction plate supported on the driven cylinder so as not to rotate relative to the driven side friction plate and slidable in the axial direction; And a lubricating oil supply mechanism that supplies lubricating oil to the friction plate.
The hydraulic brake mechanism has a pressing surface facing the outer peripheral surface of the driven cylinder, and is aligned along the longitudinal direction of the vehicle so that the pressing surface can contact and separate from the side with respect to the outer peripheral surface of the driven cylinder. The brake support shaft includes a brake shoe that is swingably supported. An outer peripheral surface of the driven cylinder and a pressing surface of the brake shoe are used as a brake operation surface.
A plate is provided on a support wall of the housing that supports an end of the PTO drive shaft facing the PTO driven shaft, and the plate includes an attachment portion attached to the support wall and a reflection surface portion extending from the attachment portion. have.
The reflection surface portion is located above the brake operation surface when viewed along the axial direction of the driven cylinder and covers the entire region in the axial direction of the brake operation surface in plan view, and the upper surface portion A side surface portion extending downward from the peripheral edge and being as close as possible to the outer peripheral surface of the driven cylinder, of the lubricating oil supplied via the lubricating oil supply mechanism, around the axis of the PTO drive shaft and it is configured to direct the lubricating oil scattered by rotating from above before Chivu rake working surface.
[0010]
Preferably, an oil groove is formed on at least one of the pressing surface of the brake shoe and the outer peripheral surface of the driven cylinder .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred embodiment of a hydraulic PTO clutch structure according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a transmission schematic diagram of a transmission 100 to which a hydraulic PTO clutch structure according to the present embodiment is applied.
[0012]
As shown in FIG. 1, the transmission 100 includes a traveling system transmission path 200 that transmits a driving force from a driving source (not shown) to a driving axle 110, and a PTO that outputs the driving force from the driving source to the outside. A system transmission path 300 and a housing 400 for housing them are provided.
The hydraulic PTO clutch structure according to the present embodiment is inserted in the PTO transmission path 300.
[0013]
2 is a longitudinal side view of the hydraulic PTO clutch structure, and is a cross-sectional view taken along line II-II in FIG. 3 is a cross-sectional view of the hydraulic PTO clutch structure, and is a cross-sectional view taken along line III-III in FIG. FIG. 4 is a plan view of the vicinity of the hydraulic PTO clutch structure. FIG. 5 is a perspective view of the hydraulic PTO clutch structure as viewed from the downstream side in the transmission direction.
[0014]
As shown in FIGS. 1 to 5, the hydraulic PTO clutch structure includes a PTO drive shaft 10 positioned on the drive side, a PTO driven shaft 20 positioned on the driven side, and the PTO drive shaft 10 to the PTO driven shaft 20. A hydraulic clutch mechanism 30 that selectively performs power transmission and power interruption, and a hydraulic brake mechanism 40 that operatively applies a braking force to the PTO driven shaft 20 in conjunction with the power interruption operation of the hydraulic clutch mechanism 30. I have.
[0015]
The PTO drive shaft 10 is operatively connected to a drive source, and is always rotated around the axis by the drive source.
The PTO driven shaft 20 can selectively transmit power from the PTO drive shaft 10 via the hydraulic clutch mechanism 30.
In the present embodiment, the PTO driven shaft 20 is disposed coaxially with the PTO drive shaft 10.
[0016]
Preferably, the PTO drive shaft 10 and the PTO driven shaft 20 are rotatable relative to each other in a state where one opposed end portion is inserted into the other opposed end portion.
In the present embodiment, as shown in FIG. 2, a concave portion 11 is provided along the axial direction at the opposed end portion of the PTO drive shaft 10, and the opposed end portion of the PTO driven shaft 20 is connected to the PTO drive shaft 10. It rushes into the recess 11.
[0017]
The hydraulic clutch mechanism 30 includes a drive-side cylinder 31 supported on the PTO drive shaft 10 so as not to rotate relative to the PTO drive shaft 10, and a drive-side friction plate 32 supported on the drive-side cylinder 31 so as not to rotate relative to the drive-side cylinder 31. And a driven cylinder 33 supported by the PTO driven shaft 20 so as not to rotate relative to the PTO driven shaft 20, and supported by the driven cylinder 33 so as not to rotate relative to the driving side friction plate 32 and to be axially slidable. The driven side friction plate 34 and a piston 35 that pushes both the drive side friction plate 32 and the driven side friction plate 33 so as to make frictional contact with each other under the action of hydraulic pressure. Power is transmitted from the PTO drive shaft 10 to the PTO driven shaft 20 by bringing the driving side friction plate 32 and the driven side friction plate 34 into frictional contact.
[0018]
As shown in FIG. 2, in the present embodiment, the hydraulic PTO clutch structure further includes a biasing member 36 that biases the piston 35 in a direction in which the piston 35 is separated from the friction plates 32 and 34. .
As described above, the hydraulic PTO clutch structure according to the present embodiment is a hydraulically operated type, but it is of course possible to be a spring operated type.
The hydraulic pressure is supplied through a hydraulic oil supply oil passage 21 drilled in the PTO driven shaft 20.
[0019]
The hydraulic brake mechanism 40 selectively operates with the PTO clutch mechanism 30 as described above.
That is, the hydraulic brake mechanism 40 does not perform the brake operation when the hydraulic clutch mechanism 30 performs the power transmission operation, and performs the brake operation when the hydraulic clutch mechanism 30 interrupts the power transmission. It is configured.
[0020]
As shown in FIG. 3, in the present embodiment, the hydraulic brake mechanism 40 is configured to act as an outer peripheral surface 33 a of the driven cylinder 33.
[0021]
Specifically, the hydraulic brake mechanism 40 includes a brake support shaft 41 supported by a support wall 410 provided in the housing 400, and a pressing surface 42a facing the outer peripheral surface of the driven cylinder 33. A brake shoe 42 swingably supported by the brake support shaft 41 so that the pressing surface 42a can come into contact with and away from the outer peripheral surface 33a of the driven cylinder 33, and a side wall 401 of the housing 400 along the vehicle width direction. A brake cylinder 43 disposed therein, a brake piston 44 which is accommodated in the brake cylinder 43 so as to be slidable in the axial direction, and whose inner end portion is capable of pushing the brake shoe 42 toward the driven cylinder 33; A biasing member 45 that biases the brake piston 44 in a direction in which the engagement between the brake shoe 42 and the driven cylinder 33 is released; There.
[0022]
In the hydraulic brake mechanism 40 having such a configuration, the brake piston 44 pushes the brake shoe 42 against the urging force of the urging member 45 under the action of the operating hydraulic pressure, whereby the brake shoe 42 The pressing surface 42 a is frictionally engaged with the brake surface 33 a, whereby a braking force is operatively applied to the PTO driven shaft 20 via the driven cylinder 33.
[0023]
In the present embodiment, the hydraulic brake mechanism 40, in addition to the urging member 45, is swayed in the brake operating direction in order to perform the brake releasing operation more reliably. Is provided with a torque spring 46 that urges the brake to rotate in the brake release direction.
[0024]
More specifically, as shown in FIGS. 3 and 4, the torque spring 46 has a base end portion 46 a engaged with the upper surface of the support wall 410 and a tip end portion 46 b engaged with the brake shoe 42. ing.
With such a configuration, the torque spring 46 urges the brake shoe 42 to rotate in the brake releasing direction, whereby the pressing surface 42a of the brake shoe 42 and the brake surface of the driven cylinder 33 are released when the hydraulic pressure is released. 33a is effectively prevented from continuing to be engaged.
[0025]
The hydraulic PTO clutch structure according to the present embodiment is further configured to supply lubricating oil to the hydraulic clutch mechanism 30 and the hydraulic brake mechanism 40.
[0026]
Specifically, at least one of the PTO drive shaft 10 and the PTO driven shaft 20 in which the opposing end portions are arranged close to each other in a relatively rotatable state, the hydraulic clutch mechanism 30 and the hydraulic brake mechanism 40 are provided. An oil passage for supplying lubricating oil is perforated.
[0027]
In the present embodiment, as described above, the recess 11 extending inward in the axial direction is provided at the opposing end of the PTO drive shaft 10, and the opposing end of the PTO driven shaft 20 is inserted into the recess 11. . In such a configuration, the lubricating oil supply oil passage 22 is bored in the PTO driven shaft 20.
[0028]
More specifically, the opposed end portion of the PTO drive shaft 10 is supported by a support wall 410 provided in the housing so as to be rotatable about its axis.
The PTO driven shaft 20 has an opposing end protruding into the recess 11 at the opposing end of the PTO drive shaft 10 and a separated end connected to the closing member 450 connected to the housing 400. Is supported rotatably.
One end portion of the lubricating oil supply oil passage 22 opens to the outer peripheral surface at the separated end portion of the PTO driven shaft 20, and the other end portion is an outer peripheral surface in the recess 11 at the opposite end portion of the PTO drive shaft 10. Open to
In the illustrated embodiment, the other end portion of the lubricating oil supply oil passage 22 is also open to the internal space of the drive side cylinder 31.
The closing member 450 is formed with a lubricating oil receiving oil passage 451 having one end opened outward and the other end communicating with the lubricating oil supply oil passage 22.
[0029]
With such a configuration, the hydraulic PTO clutch structure according to the present embodiment is operatively connected to the drive source, and lubricates the PTO drive shaft 10 that always rotates around the axis while the drive source is in operation. Oil comes to reach.
[0030]
Furthermore, in addition to the above-described configuration, the hydraulic PTO clutch structure according to the present embodiment is scattered by rotation around the axis of the PTO drive shaft 10 among the lubricating oil supplied via the lubricating oil supply oil passage 22. And a plate 50 for directing the lubricating oil toward the operating surface of the hydraulic brake mechanism 40.
[0031]
That is, as described above, in the hydraulic PTO clutch structure, the lubricating oil reaches the PTO drive shaft 10 that always rotates in conjunction with the drive source regardless of whether the hydraulic brake mechanism 30 is operated or not.
That is, the lubricating oil is scattered by the rotation of the PTO drive shaft 10 around the axis even when the hydraulic brake mechanism 40 is operated and the rotation of the driven cylinder 33 and the PTO driven shaft 20 is stopped. Is done.
The plate 50 directs the scattered lubricating oil toward the pressing surface 42a of the brake shoe 42 and the outer peripheral braking surface 33a of the driven cylinder 33 during brake operation, that is, in frictional contact. It prevents excessive wear or damage of the operating surfaces (the pressing surface 42a and the outer brake surface 33a).
[0032]
In the present embodiment, the plate 50 is disposed so as to be positioned above the brake operating surface.
Such an arrangement can be easily obtained, for example, by fixing the plate 50 to the support wall 410 of the housing 400.
[0033]
Preferably, the plate 50 may include an attachment portion 51 attached to a fixing member such as the support wall and a reflective surface portion 52 extending from the attachment portion 51.
The reflection surface portion 52 is positioned above the brake operation surface when viewed along the axial direction of the driven cylinder 33 and covers the entire region in the axial direction of the brake operation surface in plan view, And a side surface portion 52b that extends downward from the periphery of the upper surface portion 52a and is as close as possible to the outer peripheral surface 33a of the driven cylinder 33.
[0034]
Preferably, an oil groove can be provided on the pressing surface 42 a of the brake shoe 42 and / or the outer peripheral surface 33 a of the driven cylinder 33.
FIG. 6 shows a front view of the pressing surface 42 a of the brake shoe 42.
As shown in FIG. 6, when a groove is formed on the pressing surface of the brake shoe, the oil groove includes a circumferential groove along the circumferential direction of the driven cylinder, and a lateral groove intersecting the circumferential groove. Can be included.
By providing such an oil groove, it is possible to prevent stagnation of lubricating oil on the brake operating surface and to improve the efficiency of brake braking by the hydraulic brake mechanism.
[0035]
【The invention's effect】
As described above, according to the engagement belt lance mission present invention, while having a simple configuration, even when the braking force by the hydraulic brake mechanism acts operatively to the PTO driven shaft, the hydraulic brake mechanism The lubricating oil can be efficiently supplied to the brake operating surface.
[Brief description of the drawings]
FIG. 1 is a transmission schematic diagram of a transmission to which a hydraulic clutch structure according to an embodiment of the present invention is applied.
FIG. 2 is a longitudinal sectional side view of the hydraulic PTO clutch structure, and is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is a transverse sectional view of the hydraulic PTO clutch structure, and is a sectional view taken along line III-III in FIG.
FIG. 4 is a plan view of the vicinity of the hydraulic PTO clutch structure.
FIG. 5 is a perspective view of the hydraulic PTO clutch structure as viewed from the downstream side in the transmission direction.
FIG. 6 is a front view of a pressing surface of a brake shoe in the hydraulic PTO clutch structure.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 PTO drive shaft 11 Recessed portion 20 at opposite end of PTO drive shaft PTO driven shaft 22 Lubricating oil supply oil passage 30 Hydraulic clutch mechanism 31 Drive side cylinder 32 Drive side friction plate 33 Drive side cylinder 33a Outer brake surface 34 of driven side cylinder Drive side friction plate 40 Hydraulic brake mechanism 41 Brake spindle 42 Brake shoe 42a Brake shoe pressing surface 50 Plate

Claims (2)

A transmission comprising a PTO transmission path that outputs driving force from a drive source to the outside, and a housing that houses the PTO transmission path,
The PTO transmission path is operatively connected to a drive source and extends along the longitudinal direction of the vehicle, and a PTO driven shaft disposed coaxially with the PTO drive shaft so as to be positioned on the driven side. , A hydraulic clutch mechanism for selectively transmitting power to and shutting off power from the PTO drive shaft to the PTO driven shaft, and operatively applying braking force to the PTO driven shaft in conjunction with the power cut-off operation of the hydraulic clutch mechanism A hydraulic brake mechanism
The hydraulic clutch mechanism includes a drive side cylinder that is supported by the PTO drive shaft so as not to rotate relative to the PTO drive shaft, a drive side friction plate that is supported by the drive side cylinder so as not to rotate relative to the shaft, and is slidable in the axial direction, and the PTO driven A driven cylinder supported on the shaft so as not to rotate relative to the shaft; a driven friction plate supported on the driven cylinder so as not to rotate relative to the driven side friction plate and slidable in the axial direction; A lubricating oil supply mechanism for supplying lubricating oil to the friction plate;
The hydraulic brake mechanism has a pressing surface facing the outer peripheral surface of the driven cylinder, and is aligned along the longitudinal direction of the vehicle so that the pressing surface can contact and separate from the side with respect to the outer peripheral surface of the driven cylinder. A brake shoe supported swingably on a brake spindle, and an outer peripheral surface of the driven cylinder and a pressing surface of the brake shoe are used as a brake operation surface;
A plate is provided on a support wall of the housing that supports an end of the PTO drive shaft facing the PTO driven shaft;
The plate has an attachment part attached to the support wall and a reflection surface part extending from the attachment part,
The reflection surface portion is located above the brake operation surface when viewed along the axial direction of the driven cylinder and covers the entire region in the axial direction of the brake operation surface in plan view, and the upper surface portion A side surface portion extending downward from the peripheral edge and being as close as possible to the outer peripheral surface of the driven cylinder, of the lubricating oil supplied via the lubricating oil supply mechanism, around the axis of the PTO drive shaft transmissions, characterized in that it is configured to direct before Chivu rake actuating surface lubricating oil scattered by rotating from above. The transmission according to claim 1, wherein an oil groove is formed on at least one of the pressing surface of the brake shoe and the outer peripheral surface of the driven cylinder.

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