KR20240138415A - Power take off device having drag brake function - Google Patents

Abstract

A power take-off device includes a PTO housing mounted on a transmission, a drive unit receiving power from the transmission, a piston that is coupled with the drive unit and rotates together with a plurality of first friction plates, a clutch housing that accommodates the piston and rotates together with a plurality of second friction plates that are alternately arranged with the first friction plates, an output shaft that is coupled with the clutch housing and outputs power to the outside of the PTO housing, a pair of tapered bearings that are interposed between the PTO housing and the output shaft and support the output shaft from both sides, and a spring washer that pressurizes an outer ring of the tapered bearing from the outside of at least one of the tapered bearings, and when a cover of the PTO housing is assembled, a drag brake function can be imparted by preloading the outer ring of the tapered bearing through the spring washer.

Description

POWER TAKE OFF DEVICE HAVING DRAG BRAKE FUNCTION

The present invention relates to a power take-off device, and more specifically, to a power take-off device that can be applied to commercial vehicles, etc., by incorporating a drag brake function while maintaining a simple structure.

A power take-off (PTO) device is a device installed to utilize engine power for purposes other than driving a vehicle, and can be connected to an idle gear among the transmissions connected to the engine. A power take-off device can be installed on special-purpose vehicles such as trucks or fire trucks, and can be used for purposes other than driving, such as operating pumps or generating electricity.

Patent registration No. 10-1848686, Patent registration No. 10-1855872, Utility model registration No. 20-0204242, etc. disclose power take-off devices for commercial vehicles. These power take-off devices receive power from an engine and can be mounted on a transmission to transmit power to a hydraulic pump or generator, etc.

The power take-off device may include a clutch between the drive gear connected to the transmission and the output shaft. When the clutch is connected, power from the engine is transmitted from the drive gear to the output shaft, but the output shaft may be rotated by the drag force generated within the clutch, and this may be controlled by an external separate device to prevent this, or a safety device is required to prevent a failure that may be caused by the rotation of the output shaft.

The conventional method of controlling the power take-off from outside has the burden of having to be designed twice because it must be controlled separately from the operation of the power take-off, and problems such as malfunction due to separate control and reduced fuel efficiency due to unnecessary power loss still remain.

The present invention provides a power take-off device having a built-in drag brake function and capable of stopping an output shaft by exerting the drag brake function when a clutch is disengaged.

The present invention provides a power take-off device in which a drag brake function is implemented in a simple structure, thereby enabling the power take-off device to be formed compactly.

According to an exemplary embodiment of the present invention for achieving the objects of the present invention described above, a power take-off device includes a PTO housing mounted on a transmission, a driving unit receiving power from the transmission, a piston that is coupled with the driving unit and rotates together with a plurality of first friction plates, a clutch housing that accommodates the piston and rotates together with a plurality of second friction plates that are alternately arranged with the first friction plates, an output shaft that is coupled with the clutch housing and outputs power to the outside of the PTO housing, a pair of tapered bearings interposed between the PTO housing and the output shaft and supporting the output shaft from both sides, and a spring washer that pressurizes an outer ring of the tapered bearing from the outside of at least one of the tapered bearings, and when a cover of the PTO housing is assembled, a drag brake function can be imparted by preloading the outer ring of the tapered bearing through the spring washer.

In a pair of facing tapered roller bearings, the outer ring can be pressurized to form a bearing preload, and a spring washer can be used to increase space efficiency and simplify the preload structure.

In this specification, a spring washer is a washer capable of providing continuous pressure in the axial direction, and in addition to a conical washer, a wave washer, a crinkle washer, a split washer, etc. can also be used.

A spacer (spacer or shim) may be provided to adjust the clearance between the spring washer and the surrounding structure, and the bearing preload can be adjusted through the spacer. The spacer may be provided between the spring washer and the tapered bearing outer ring, but may also be provided between the spring washer and the cover, and may be provided both in front and behind the spring washer.

The PTO housing may include a front cover supporting the front end of the output shaft and a rear cover passing through the rear end of the output shaft, centered on a central body in which a clutch housing, etc. are built. When assembling the front cover and the rear cover centered on the body, tapered bearings may be provided between the front cover and the output shaft and between the rear cover and the output shaft, respectively.

A pair of tapered bearings are installed facing each other with the outer ring facing outward, and the outer surface of the outer ring may be supported by a spring washer or spacer.

The power take-off device for a commercial vehicle of the present invention has a built-in drag brake, so there is no need to add a separate brake device to fix the output shaft externally, and even in a situation where a clutch is separated using the power take-off device, a drag brake function can be implemented by bearing preload.

The drag brake function can be implemented in a simple structure by using a spring washer or spacer, and various preload adjustments are possible by adjusting the spring washer or spacer. In addition, a compact device configuration is possible while including the drag brake function.

FIG. 1 is a perspective view illustrating a power take-off device according to one embodiment of the present invention.
Figure 2 is a rear view for explaining the power take-off device for a commercial vehicle of Figure 1.
Figure 3 is a cross-sectional view illustrating the AA section of Figure 2.
Figure 4 is an exploded view for explaining the output shaft coupling process of the commercial vehicle power take-off device of Figure 1.
Figure 5 is an enlarged view for comparison of parts F and R of Figure 3.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings, but the present invention is not limited or restricted by the embodiments. For reference, in this description, the same numbers refer to substantially the same elements, and the contents described in other drawings under the above rules may be cited and described, and the contents that are judged obvious to those skilled in the art or are repeated may be omitted.

FIG. 1 is a perspective view for explaining a power take-off device according to one embodiment of the present invention, FIG. 2 is a rear view for explaining the power take-off device for a commercial vehicle of FIG. 1, FIG. 3 is a cross-sectional view illustrating the section A-A of FIG. 2, FIG. 4 is an exploded view for explaining an output shaft coupling process of the power take-off device for a commercial vehicle of FIG. 1, and FIG. 5 is an enlarged view for comparing parts F and R of FIG. 3.

Referring to FIGS. 1 to 5, a power take-off device (100) according to the present embodiment can be installed in a transmission (10) of an automobile and can receive power through a driving gear (120).

Power transmitted through the drive gear (120) can be transmitted to the output shaft (150) through an internal clutch structure, and the power take-off device (100) can be mounted or separated from a transmission (10) or the like through the base (112) where the drive gear (120) is located.

The power take-off unit (100) may include a PTO housing (110), a drive gear (120), a piston (130) that rotates with a first friction plate (135), a clutch housing (140) that rotates with a second friction plate (145), an output shaft (150), a spring washer (160), a spacer (170), and a hydraulic device (190).

The PTO housing (110) can be mounted on the side, top or bottom of the transmission (10) through the base (112), and the drive gear (120) can be exposed around the base (112) and connected to the internal gear of the transmission (10). In general, when the vehicle is stopped, the power take-off device (100) can be connected to the idle gear of the transmission (10) to receive power.

An output shaft (150) may be provided at the center of the PTO housing (110), and a piston (130) may be provided around the output shaft (150). The piston (130) may be provided with power in conjunction with the driving gear (120), and while the driving gear (120) rotates, the piston (130) may also rotate together. A spline may be formed on the outer surface of the piston (130), and a plurality of first friction plates (135) may be provided that mesh with the spline and rotate together.

A clutch housing (140) is provided outside the piston (130) and the first friction plate (135), and a plurality of second friction plates (145) can be arranged along the side slots of the clutch housing (140). The second friction plates (145) are arranged alternately with the first friction plate (135), and the first friction plate (135) and the second friction plate (145) can be frictionally coupled or separated from each other according to the movement of the piston (130).

When the piston (130) moves toward the opening of the clutch housing (140) by the hydraulic device (190), etc., the gap between the first friction plate (135) and the second friction plate (145) narrows and they come into contact with each other, and the piston (130) and the clutch housing (140) can enter a clutch connection state in which they rotate together. Conversely, when the piston (130) moves in the opposite direction, the gap between the first friction plate (135) and the second friction plate (145) can increase, and the piston (130) and the clutch housing (140) can enter a clutch disengagement state in which they do not rotate together.

The clutch housing (140) is connected to the output shaft (150) through a clutch bottom having a spline structure formed in the center, and when the clutch housing (140) is in a clutch connection state connected with the piston (130), the output shaft (150) can rotate by receiving power from the drive gear (120).

Tapered roller bearings (154, 156) are arranged in a frontal direction on both sides of the output shaft (150), and a spacer (170) and a spring washer (160) may be sequentially provided on the outer surface of the tapered bearing (154) arranged at the rear end of the output shaft (150).

The spring washer (160) can be pressurized by assembling the PTO housing (110) and the rear cover (114), and can preload the outer ring (154') of the tapered bearing (154). By pressurizing the outer rings of the pair of opposing tapered bearings (154, 156), a drag brake function for the output shaft (150) can be implemented when the clutch is disengaged.

In this embodiment, the spring washer (160) can be used alone, but can be provided in various combinations. For example, two or more spring washers can be overlapped or various sizes can be combined, and the direction of overlap can also be varied in the same direction or different directions. In addition to the conical washer, the spring washer (160) can also be a wave washer, a crinkle washer, a split washer, etc.

One or more spacers (170) can be used in an overlapping manner, and the bearing preload can be adjusted by adjusting the spacing. The spacer (170) can be provided between the spring washer (160) and the outer ring (154') of the tapered bearing, but can also be provided between the spring washer (160) and the rear cover (114).

Referring to Fig. 4, before assembling the rear cover (114), a tapered bearing (154), a spacer (170), and a spring washer (160) are fitted to the output shaft (150), and a bearing preload can be formed while assembling the rear cover (114).

A coupling (152) may be provided at the rear end of the output shaft (150), and the power take-off device (100) may be connected to an external pump or other additional device through the coupling (152).

In this embodiment, a hydraulic device (190) is provided to operate the piston (130), but a separate lever or wire device may also be provided.

Looking at F and R of FIG. 5, while pressurizing the spring washer (160) with the rear cover (114), the outer ring (154') of the tapered bearing (154) located at the rear end of the output shaft (150) is pressed, and at the same time, the outer ring (156') of the tapered bearing (156) located at the front end of the output shaft (150) can also be supported by the front cover (116).

The piston (130) may move backward, i.e., to the right in the drawing, by the removal of pressure by the hydraulic device (190), the change of the pressure direction by the hydraulic pressure, the restoring force of the spring, etc. As the piston (130) moves to the right, the first friction plate (135) and the second friction plate (145) may be separated from each other, and the rotation of the piston (130) may not be transmitted to the clutch housing (140). The friction plates should be separated so that the rotation of the piston (130) is not transmitted to the clutch housing (140), but as the rotation of the rotating first friction plate (135) is transmitted to the second friction plate (145) as a drag force, the clutch housing (140) may receive a force to rotate together.

To prevent this, the preload formed by the spring washer (160) and spacer (170) can prevent the output shaft (150) from rotating due to drag force or external force.

As described above, while the present invention has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various modifications and changes may be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

100 : Power take-off unit 110 : PTO housing
120 : Drive Gear 130 : Piston
135: First friction plate 140: Clutch housing
145: Second friction plate 150: Output shaft
160 : Spring washer 170 : Spacer
190 : Hydraulic device

Claims (5)

PTO housing mounted on the transmission;
A driving unit that receives power from the above transmission;
A piston that rotates together with a plurality of first friction plates and is linked to the above driving unit;
A clutch housing that accommodates the piston and rotates together with a plurality of second friction plates arranged alternately with the first friction plates;
An output shaft that is coupled with the clutch housing and outputs power to the outside of the PTO housing;
A pair of tapered bearings interposed between the PTO housing and the output shaft and supporting the output shaft on both sides; and
A spring washer for pressing the outer ring of the tapered bearing on the outside of at least one of the tapered bearings;
A power take-off device characterized in that the outer ring of the tapered bearing is preloaded through the spring washer when the cover of the PTO housing is assembled.
In the first paragraph,
A power take-off device characterized in that the above spring washer uses a conical washer, a wave washer, a crinkle washer or a split washer.
In the first paragraph,
A power take-off device, characterized in that at least one spacer is interposed between the spring washer and the outer ring of the tapered bearing or between the spring washer and the cover.
In the first paragraph,
The above PTO housing includes a front cover supporting the front end of the output shaft and a rear cover passing through the rear end of the output shaft.
A power take-off device characterized in that the tapered bearings are provided between the front cover and the output shaft and between the rear cover and the output shaft, respectively.
In the first paragraph,
A power take-off device, characterized in that the pair of tapered bearings are installed in a frontal direction.

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