JPH04285331A - Clutch mechanism for power take-off device - Google Patents

Abstract

PURPOSE:To dispense with a member interlocking with an output shaft to reduce power loss by separating a clutch plate from a disc plate through a disc spring to prevent the insufficient disengagement of a clutch caused by oil between the above plates, and rotating the output shaft separatingly from a piston or the like. CONSTITUTION:In the engaged state of a clutch, a pressure oil is sucked through an inlet port 46, and a piston 45 presses a multiplate body 40 against the force of a disc spring 41. Clutch plates 39 are therefore brought into pressed contact with one disc plate 38 on both its sides, and frictional force between the plates transmits power from an output gear 34 to an output shaft 35. On the other hand, in the disengaged state of the clutch, since the pressure of the pressure oil sent to the inlet port 46 is reduced, the piston 45 is left from the multiplate body 40 by the force of the disc spring 41. In this case, the disc spring 41 certainly separates the clutch plate 39 from the disc plate 38. Since the output shaft 35 rotates separately from the piston 45 and a cylinder 42, the piston 45 does not follow the rotation of the output shaft 35.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] The present invention relates to specially equipped vehicles such as dump trucks, mixer trucks, refrigerated trucks, etc., which are equipped with a power extraction device for extracting power for purposes other than driving. The present invention relates to a clutch mechanism that connects and disconnects power.

0002

[Prior Art] Specially equipped vehicles such as dump trucks, mixer trucks, refrigerated trucks, etc. supply power from the engine to load devices that require power in addition to the traveling device, and power extraction is required for this purpose. The device (referred to as PTO) is, for example, a transmission system in which the PTO2 is attached to a predetermined gear of the transmission 1 as shown in FIG. 4, or a flywheel system in which the PTO2 is attached to the crankshaft of the engine 4 as shown in FIG. There are methods etc. The method shown in FIG. 4 uses the power of the engine 4 via the clutch 3, so the PT
The power connection/disconnection of O is performed by the clutch 3. Therefore, if the clutch is disengaged during a temporary stop such as waiting at a traffic light, no power will be supplied to the load device. The system shown in Fig. 5 can independently connect and disconnect power to the traveling device and the load device, and can prevent power from being transmitted to the load device even if the clutch for the traveling device is disconnected. It is possible. In addition, in the case of Fig. 5, the clutch is connected to transmission 1.
Built-in.

The system shown in FIG. 5 requires a clutch that connects and disconnects the PTO output using a dedicated pump or a power steering pump. FIG. 6 shows an example of a conventional clutch device installed in the PTO. An idler gear 11 that derives a PTO output from an engine crankshaft (not shown) meshes with an output gear 14. The output gear 14 is rotatably supported by an output shaft 15 directly connected to a load device via a needle bearing 16, and one end of the output shaft 15 is connected to a joint retainer 17 to provide power to the load device (not shown). The other end is supplied with the inner clutch hub 18, piston 19 and cylinder 20.
is attached and supported by the housing 12.

The output gear 14 has a cylindrical portion 14a formed so as to have a coaxial positional relationship with the inner clutch hub 18, and the space between the outer peripheral surface of the inner clutch hub 18 and the inner peripheral surface of the cylindrical portion 14a is used as a clutch. It is configured as a chamber 13. The clutch chamber 13 includes a clutch plate group 2.
1 and a group of disk plates 22 are alternately engaged to form a multi-plate body 23. The clutch plate group 21 is made movable in the axial direction by a spline 18b formed on the outer circumference of the inner clutch hub 18, and the disc plate group 22 is made movable in the axial direction by a spline 14b formed on the inner circumference of the cylindrical portion 14a. ing. The multi-plate body 23 is displaced within the clutch chamber 13 between a pressed state (clutch connected state) and a separated state (clutch disengaged state) by a piston 19 that is moved in the axial direction by pressure oil, so that it performs a clutch operation. ing.

The cylinder 20 is equipped with a piston 19, and the clutch connection state and the clutch are controlled depending on whether pressure oil from a power steering pump, for example, is supplied to the pressure chamber defined by the cylinder 20 and the piston 19, or whether the pressure is reduced. Switching between the cut-off state and the cut-off state is performed. Pressure oil is supplied through an input passage 24 bored in the housing 12 and a passage 25 bored in the output shaft 15. In addition, the piston 19 and the inner clutch hub 1
A coil spring 26 is interposed between the pistons 8 and 8 to press the piston 19 toward the cylinder 20.

In the above clutch device, the piston 19 is moved toward the inner clutch hub 18 by pressure oil from the pump.
When pressed in the direction of arrow A), the disc plate group 21 and the clutch plate group 22 come into pressure contact and the clutch is connected, and the power from the idler gear 11 is transferred from the output gear 14 to the multi-plate body 23 to Inner clutch hub 18
The signal is transmitted to the output shaft 15 through the path. Also, when the oil pressure is lowered, the force of the coil spring 26 causes the piston 19 to
is returned in the opposite direction A, the disk plate group 21 and the clutch plate group 22 are separated (clutch disengaged state), and the power from the idler gear 11 is no longer transmitted to the output shaft 15.

[0007]

By the way, the clutch device described above is constructed so that the piston 19, cylinder 20, and coil spring 26 rotate at the same time as the output shaft 15, and the inertial mass of the output shaft 15 becomes large. This increases the moment of inertia, which increases power loss. This is because the inner clutch hub 18 is added in order to cause the coil spring 26 to act between the multi-plate body 23 and the piston 19, and in addition, the size is increased in the radial direction for this purpose.

Furthermore, when the clutch is disengaged, the coil spring 26 quickly retreats the piston 19 to release the restraint from the multi-plate body 23, but the interior of the housing 12 from between each plate to the idler gear 11 is completely oil-free. The shear force of the oil between the plates causes a dragging phenomenon between the plates, which causes clutch disengagement failure.

SUMMARY OF THE INVENTION An object of the present invention is to provide a clutch mechanism for a power take-off device that eliminates a coil spring that acts directly on a piston, prevents the plate-to-plate dragging phenomenon, and reduces the inertial mass applied to the output shaft. .

0010

[Means for Solving the Problems] The present invention provides an output gear of a power take-off device in which a cylinder is integrally formed, an output shaft that supports the output gear in a relatively rotatable manner, and a cylinder that is allowed to move only in the axial direction. a multi-plate body consisting of a group of disc plates and a group of clutch plates that alternately overlap with the group of disc plates and are sheathed to the output shaft so as to be allowed to move only in the axial direction; A group of interposed disk springs, a cylinder device that presses the multi-plate body to connect them by frictional force, and a thrust bearing interposed between the piston of the cylinder device and the multi-plate body. Be equipped.

[0011]

[Operation] According to the above, when the clutch is in the connected state, the disc spring is compressed by the pressing force of the piston, the plates are brought into pressure contact with each other, and the rotation from the output gear is transmitted to the output shaft by the frictional force. At this time, the piston contacts the multi-plate body through the thrust bearing, and does not act as an element that increases the moment of inertia of the output shaft. When the clutch is in a disengaged state, the piston is retracted from the multi-plate body by the resilient force of the disc spring, and the distance between adjacent clutch plates is forcibly expanded. This ensures that the clutch plate group and the disc plate group are separated.

0012

EXAMPLES The present invention will be explained in detail below using specific examples. FIG. 1 is a sectional view showing an embodiment of a clutch mechanism of a power extraction device according to the present invention, FIG. 2 is an explanatory view showing a disengaged state of the clutch, and FIG. 3 is an explanatory view of an engaged state of the clutch.

The idler gear 31 is housed in a housing made up of a front case 32 and a rear case 33 which are overlapped with each other through a crankshaft (not shown), and an output gear 34 provided in the housing and a ball bearing that connects the gear 34. Power from the engine can be transmitted to the rotatably supported output shaft 35 via the shaft 36. The output gear 34 is formed with a cylindrical portion 34a having one end of the output shaft 35 as its axis, and the cylindrical portion 34a is rotatably supported by the front case 32 via a needle bearing 37. A clutch chamber is formed between the cylindrical portion 34a and the output shaft 35. A spline 34b that coincides with the axial direction of the output shaft 35 is provided on the inner peripheral surface of the cylindrical portion 34a.
is formed, and a disk plate group 38 is anchored to the spline 34b, so that the disk plate group 38 is movable in the axial direction. On the other hand, a spline 35a extending in the same direction as the spline 34b is formed on the outer peripheral surface of one end of the output shaft 35, and a clutch plate group 39 is moored to the spline 35a, so that the clutch plate group 39 is movable in the axial direction. has been done. These disk plate group 38 and clutch plate group 39 mesh alternately to form a multi-plate body 40 (see FIGS. 2 and 3). Here,
In this embodiment, a disc spring 41 is interposed on the clutch plate group 39 side so as to overlap in a V-shape. In addition, the multi-plate body 40
In this embodiment, the number of clutch plate groups 39 is one more than the disk plate group 38 and an odd number so that clutch plates 39 are interposed from both sides of one disk plate 38.

Next, the output shaft 35 is rotatably supported by the cylinder 42 and rear case 33 as described below. The front case 32 has an opening for receiving the needle bearing 37, and the cylinder 42
is attached so as to cover the opening of the needle bearing 37. The cylinder 42 has a cylindrical shape with a bottom,
A bolted bearing 43 is attached to its bottom. Needle rollers 44 are arranged within the bearing 43, and one end of the output shaft 35 is supported by the bearing 43 via the roller 44. The other end of the output shaft 35 is connected to the rear case 33 via a tapered roller bearing 51.
A joint retainer 50 is attached to the joint retainer 50.

Piston 45 mounted within cylinder 42
surrounds the bearing 43 coaxially, and is reciprocated in the axial direction relative to the multi-plate body 40 by pressure oil from an inlet 46 formed at the bottom. 47 is a pressure regulating valve. Further, a thrust bearing 48 is attached to the end surface of the piston facing the multi-plate body 40, and the thrust bearing 48 is in contact with the multi-plate body 40 via a small hub 49.

Here, when the piston 45 is mounted on the output shaft 35, the disc spring 42 is made to be in a slightly compressed state. Thereby, when the output shaft 35 is supported by the tapered roller bearing 37, a preload is applied to the tapered roller bearing 51 by the disc spring 41, and rattling after assembly can be prevented. The clutch device configured as described above operates as follows.

Clutch engaged state: The clutch engaged state is shown in the lower half of FIG. 1 and in FIG. That is, by sucking pressure oil through the suction hole 46, the piston 45 assumes a position in which it presses the multi-plate body 40 in the A direction against the force of the disc spring 41. As a result, the clutch plates 39 come into pressure contact with one disc plate 38 from both sides, and power is transmitted from the output gear 34 to the output shaft 35 by the frictional force between both plate groups.

Clutch Disengaged Condition: The clutch disengaged condition is shown in the upper half of FIG. 1 and in FIG. That is, by reducing the pressure of the pressure oil into the suction hole 46, the piston 45 is retracted from the multi-plate body 40 by the force of the disc spring 41.
(move in the opposite direction of A). As a result, the distance between the clutch plates 39 on both sides adjacent to one disc plate 38 increases, the clutch plates 39 are reliably separated from each disc plate 38, and the transmission of power from the output gear 34 to the output shaft 35 is interrupted. .

According to this device, when the clutch is switched from the connected state to the disengaged state, the disc spring 41 connects the clutch plates 39 on both sides with respect to one disc plate 38.
This makes it possible to reliably separate the plates and prevent clutch disengagement caused by oil existing between the plates. Furthermore, since the output shaft 35 rotates independently of the piston 45 and cylinder 42, the piston 4
5 does not follow the rotation of the output shaft 35. In this way, the output shaft 35 rotates without involving other coaxial members such as the piston 45, and there are fewer elements that increase the moment of inertia than in the past, reducing the loss of power consumed by other than the load device. be able to.

Furthermore, compared to the conventional configuration, this device eliminates the coil spring and inner clutch hub, and integrates the disc spring 41, which fulfills the mission of a coil spring, into the multi-plate body 40, so that the output shaft There is an advantage that the radial dimension of 35 is reduced.

[0021]

[Effects of the Invention] As described above, according to the present invention, there is no need for any member that interlocks with the output shaft, thereby reducing the moment of inertia and reducing power loss, as well as forcibly separating the plates of a multi-plate body. This has the effect of increasing the reliability of preventing clutch disconnection failures.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing one embodiment of a clutch mechanism of a power take-off device according to the present invention.

[Fig. 2] An explanatory diagram showing a clutch disengaged state of the device shown in Fig. 1.

[Fig. 3] An explanatory diagram showing the clutch connection state of the device shown in Fig. 1.

[Figure 4] Explanatory diagram explaining the transmission method

[Figure 5] Explanatory diagram explaining the flywheel method

[Fig. 6] A sectional view showing an example of a conventional clutch device.

[Explanation of symbols]

31-Idler gear, 34-Output gear, 34a-Cylinder part, 35-Output shaft, 34b, 35a-Spline, 36-
Ball bearing, 38-disk plate group, 39-clutch plate group, 40-multi-plate body, 41-disc spring, 42-
Cylinder, 43-bearing, 44-roller, 48-thrust bearing.

Claims (1)

[Claims] 1. An output gear of a power take-off device integrally formed with a cylinder, an output shaft supporting the output gear so as to be relatively rotatable, a group of disc plates in which the cylinder is allowed to move only in the axial direction, and the disc plate. a multi-plate body consisting of groups of clutch plates that alternately overlap the groups and are externally mounted on the output shaft so as to be allowed to move only in the axial direction; and a group of disc springs interposed to separate the gaps between the groups of clutch plates; , a power take-off device comprising: a cylinder device that presses the multi-plate body to connect them by frictional force; and a thrust bearing interposed between the piston of the cylinder device and the multi-plate body. clutch mechanism.