CN220337446U

CN220337446U - Power takeoff

Info

Publication number: CN220337446U
Application number: CN202321837709.8U
Authority: CN
Inventors: 胡小冬; 梁琼; 刘宇辉
Original assignee: Xuzhou Heavy Machinery Co Ltd
Current assignee: Xuzhou Heavy Machinery Co Ltd
Priority date: 2023-07-13
Filing date: 2023-07-13
Publication date: 2024-01-12
Anticipated expiration: 2033-07-13

Abstract

The utility model discloses a power takeoff, wherein a power takeoff shell is provided with a power takeoff cylinder at one side, and a cylinder shaft of the power takeoff cylinder vertically extends into the power takeoff shell; a combining sleeve is arranged in the central hole of the input gear, the combining sleeve is in circumferential limit connection with the input gear, one end of the combining sleeve extends out of the power takeoff shell, the extending end of the combining sleeve is in meshed connection with a power take-off shaft of the gearbox through an end face tooth structure, and the power take-off shaft of the gearbox is linked with the combining sleeve to drive the input gear to rotate; the cylinder shaft extends into the combining sleeve and is in axial limiting connection with the combining sleeve, and the cylinder shaft drives the combining sleeve to axially move so as to realize connection and disconnection between the combining sleeve and the power take-off shaft of the gearbox; when the rotation speed of the power take-off shaft of the gearbox is reduced, the combined sleeve automatically slides out of the engagement position under the action of torque, and the combined sleeve and the power take-off shaft of the gearbox can be automatically disconnected. The utility model can simplify the gear engaging structure and improve the gear engaging success rate; the power connection can be automatically cut off by utilizing the structure of the engine, so that the engine is prevented from being reversely towed.

Description

Power takeoff

Technical Field

The utility model relates to a power takeoff.

Background

The power takeoff is an important part of various engineering special vehicles, and the power takeoff is usually required to be installed in the engineering machinery and special vehicle fields to realize the operation of other devices of the whole vehicle, such as lifting and turning of a crane, turning of a dump truck and the like. At present, an actuating mechanism of a power takeoff commonly used on a vehicle generally adopts a mode that a power take-off cylinder is connected with a shifting fork to shift a gear sleeve for hanging, but the structure can have the risk of loosening and clamping stagnation of the shifting fork.

In addition, the power take-off switch of the existing power take-off device generally adopts a contact switch with mechanical contact to judge whether the hooking is successful, the problems of contact abrasion and clamping stagnation can occur when the power take-off device works for a long time, the situation that the gear judgment is wrong and the like due to the fact that the position of a shifting fork cannot be detected in real time can be avoided, and the reliability of the power take-off device can be reduced.

In addition, in order to protect the engine from being reversely towed during heavy-load operation, when the engine speed is reduced to a certain speed in the power taking process, the gearbox and the complete machine control system are required to be disconnected for power taking so as to avoid the reverse towing condition caused by engine stall. The existing power takeoff has no automatic disengaging structure, power cannot be automatically cut off, the power is required to be disengaged by means of a control system, and once the control system has a problem, the power takeoff cannot be disengaged, and the engine is reversely towed.

Disclosure of Invention

The utility model aims to: the utility model aims to provide a power takeoff which adopts a direct-push type gear engaging mechanism and a non-contact Hall switch and can automatically cut off power connection.

The technical scheme is as follows: the utility model relates to a power takeoff, which comprises a power takeoff shell, wherein an input gear and an output gear which are in meshed transmission are arranged in the power takeoff shell, and the input gear is provided with a through center hole; the power take-off device is characterized in that a power take-off cylinder is arranged on one side of the power take-off device shell, and a cylinder shaft of the power take-off cylinder vertically extends into the power take-off device shell; a combining sleeve is arranged in the central hole of the input gear, the peripheral side of the combining sleeve is in circumferential limit connection with the central hole of the input gear, one end of the combining sleeve extends out of the power takeoff shell, the extending end of the combining sleeve is in meshed connection with a power take-off shaft of the gearbox through an end face tooth structure, and the power take-off shaft of the gearbox is linked with the combining sleeve to drive the input gear to rotate during meshed connection; the cylinder shaft stretches into the inside of the combining sleeve and is in axial limiting connection with the combining sleeve, and when the cylinder shaft moves, the cylinder shaft drives the combining sleeve to axially move so as to realize connection and disconnection of the combining sleeve and the power take-off shaft of the gearbox.

Preferably, a piston is arranged in the power taking cylinder, and breathing holes and air inlets are respectively formed in two sides of the piston of the power taking cylinder; the cylinder shaft is fixedly connected with the piston, a return spring is sleeved outside the cylinder shaft, and the return spring is arranged in the spring seat and is abutted between the spring seat and the piston; when the combination sleeve is in meshed connection with the transmission power taking shaft, the air inlet hole keeps high-pressure air inlet, and the return spring is compressed to the position of maximum elastic potential energy; when the combining sleeve is disconnected with the power take-off shaft of the gearbox, the air inlet is cut off, and the return spring drives the piston and the cylinder shaft to move and return.

Preferably, a displacement sensor for detecting the position of the cylinder shaft is arranged at the outer end part of the power taking cylinder, the displacement sensor comprises a fixedly arranged induction hole and a movable shaft arranged outside the piston, the piston drives the movable shaft to move back and forth in the induction hole, the displacement sensor can detect the position of the cylinder shaft in real time, and the power taking device is judged to be in a gear and out-of-gear state; the displacement sensor adopts a non-contact structure, so that the problems of abrasion, clamping stagnation and the like can be avoided.

Preferably, the end faces of the combining sleeve and the gearbox power take-off shaft are provided with end face teeth, and tooth faces of the end face teeth comprise planes, arc end faces and inclined planes; when the combination sleeve is driven by the cylinder shaft to be meshed with the transmission power take-off shaft, the inclined planes of the two end face teeth are in fit interaction with the inclined planes, and the combination sleeve and the transmission power take-off shaft rotate relatively; the plane of the end face teeth of the engaged combined sleeve and the transmission power take-off shaft are attached to the plane to transfer torque; the arc end surface can ensure that the motion retardation phenomenon of the tooth top teeth can not occur in the meshing process.

Preferably, when the rotating speed of the power take-off shaft of the gearbox is reduced, the combining sleeve automatically slides out of the meshing position along the inclined plane of the end face teeth under the action of torque, and the combining sleeve and the power take-off shaft of the gearbox are automatically disconnected, so that the reverse dragging condition of the engine can not occur.

Preferably, the input gear is connected with the combining sleeve through spline fit, and keeps synchronous rotation; the coupling sleeve slides axially along the splined bore of the input gear.

Preferably, an inner hole is formed in the middle of the combination sleeve, the cylinder shaft and the inner hole of the combination sleeve are in rotary connection through the cooperation of a bearing bush, and gaskets and snap springs for axial limiting are arranged on two sides of the bearing bush; the coupling sleeve and the cylinder shaft are kept to axially and synchronously move.

The beneficial effects are that: compared with the prior art, the utility model has the following advantages: 1. the direct-pushing type gear shifting mechanism is adopted, so that the problems of loosening and clamping stagnation of a shifting fork existing in the traditional shifting fork type gear shifting structure can be avoided, meanwhile, the gear shifting structure is simplified, the end face bevel gear structure is adopted by the combining sleeve, the arc end face of the end face gear cannot be provided with tooth tops during gear shifting, and the inclined plane of the combining sleeve pushes the inclined plane of the power take-off shaft of the gearbox, so that the gear shifting success rate can be improved; 2. the non-contact Hall sensor is adopted, so that the problems of contact wear and clamping stagnation of a mechanical contact switch can be avoided, and the detection accuracy is improved; 3. the power takeoff structure can cut off the power connection during heavy load, and the engine can not be reversely towed.

Drawings

FIG. 1 is a schematic diagram of the structure of the present utility model;

FIG. 2 is a schematic view of the present utility model in a engaged state;

FIG. 3 is a schematic diagram of the end face bevel gear structure of the present utility model;

FIG. 4 is a schematic view of another angular end face bevel gear configuration of the present utility model;

FIG. 5 is a schematic diagram of the working principle of the end face bevel gear of the present utility model;

fig. 6 is a schematic diagram of the working principle of the end face bevel gear reverse dragging state of the utility model.

Detailed Description

The technical scheme of the utility model is further described below with reference to the accompanying drawings.

As shown in fig. 1, a power take-off includes a power take-off housing 4, a power take-off base 3, a power take-off cylinder 11, an input gear 5, and an output gear 30.

The power take-off cylinder 11 is horizontally arranged on one side of the power take-off housing 4 and comprises a piston 16, a cylinder shaft 7, a spring seat 10 and a return spring 12, a through hole boss is arranged on the left side of the power take-off cylinder 11, and the power take-off cylinder extends into the power take-off housing 4 to be fixedly connected with the power take-off housing 4. One end of the cylinder shaft 7 is fixedly connected with the piston 16 through a cylinder shaft nut 17, and a piston inner sealing ring 15 is arranged on the contact surface; a piston outer sealing ring 13 is arranged at the contact part of the periphery of the piston 16 and the inner wall of the cylinder; the other end of the cylinder shaft 7 passes through a spring seat 10 and a perforated boss and stretches into a central hole of an input gear 5 in the power takeoff, the spring seat 10 is fixedly arranged on the left end face of a power take-off cylinder 11, and a cylinder shaft sealing ring 8 is arranged on the contact surface of the cylinder shaft 7 and the inner wall of the perforated boss; the return spring 12 is fitted over the cylinder shaft 7 and abuts between the spring seat 10 and the piston 16.

The right end of the power taking cylinder 11 is provided with a cylinder cover 18, and the right side of the piston 16 is limited by a positioning step of the cylinder cover 18. The piston 16 divides the power taking cylinder 11 into a left cavity and a right cavity, a breathing hole 9 is arranged on the side wall of the shell of the left cavity, and an air inlet hole 14 is arranged on a cylinder cover 18 of the right cavity. The cylinder cover 18 is provided with a displacement sensor 20, and the displacement sensor 20 is connected with the cylinder cover 18 in a matching way through a displacement sensor sealing ring 19; the displacement sensor 20 is provided with a sensing hole 21, the right side of the piston 16 is fixedly connected with a moving shaft 22, the moving shaft 22 is driven by the piston 16 and the cylinder shaft 7 to horizontally move in the sensing hole 21, and the displacement sensor 20 can detect the position of the cylinder shaft 7 in real time.

The input gear 5 is supported in the power take-off housing 4 and the power take-off housing 3 by an input gear left bearing 2 and an input gear right bearing 6, respectively. The input gear 5 is provided with a central hole in which the coupling sleeve 1 is mounted. The coupling sleeve 1 is spline-fitted with the input gear 5 and is axially slidable with respect to the input gear 5. The left end of the cylinder shaft 7 is matched with the inner hole of the combining sleeve 1 through a cylinder shaft bearing bushing 33, and the cylinder shaft 7 is prevented from rotating when the combining sleeve 1 rotates. The two sides of the inner hole of the combination sleeve 1 are limited through the cylinder shaft gasket 32 and the combination sleeve clamp spring 34, and the cylinder shaft 7 can drive the combination sleeve 1 to axially slide.

The output gear 30 is supported in the power take-off base 3 and the power take-off housing 4 by an output gear left bearing 31 and an output gear right bearing 29, respectively. The input gear 5 and the output gear 30 are meshed for transmission. One end of an output gear 30 extends out of the power takeoff housing 4 and is connected with an output flange 28, the right side of the output gear 30 is matched with the output flange 28 through a spline, and an inner hole of the output flange 28 is fixedly connected with the output gear 30 through a locking gasket 26 and a locking nut 27. The outer ring of the right bearing 29 of the output gear is limited by the oil seal seat 23, and the inner ring is limited by the output flange 28. Two oil seals 25 are arranged on the inner side of the oil seal seat 23, and the inner diameter of each oil seal 25 is matched with the outer diameter of the output flange 28; the dust cover 24 is installed to the outer tip of oil blanket seat 23, and dust cover 24 periphery pressure equipment is at the outer border of oil blanket seat 23 tip, and the internal diameter of dust cover 24 cooperatees with the external diameter of output flange 28.

The utility model is connected with a gearbox power take-off shaft 35 through a coupling sleeve 1. As shown in fig. 1-6, to protect the engine from reverse drag, the coupling sleeve 1 is cooperatively connected with the end face of the transmission power take-off shaft 35 by an end face bevel gear structure. As shown in fig. 3, the end face teeth of the transmission power take-off shaft 35 include a flat face 35c, an inclined face 35b, and a circular arc end face 35a; as shown in fig. 4, the end face teeth of the coupling sleeve 1 include a flat face 1c, an inclined face 1b, and a circular arc end face 1a. When in engagement or disconnection, the inclined plane 35b of the end face teeth of the coupling sleeve 1 and the gearbox power take-off shaft 35 are in fit interaction with the inclined plane 1 b; after engagement, the flat surfaces 35c of the end teeth of the coupling sleeve 1 and the transmission power take-off shaft 35 are fitted with the flat surfaces 1c to transmit torque.

As shown in fig. 5, when the gear is engaged, the coupling sleeve 1 is moved leftward by the cylinder shaft 7, and the end face teeth of the coupling sleeve 1 and the transmission power take-off shaft 35 are not tooth-top teeth due to the existence of the circular arc end face. The coupling sleeve 1 receives axial thrust force F, and the inclined plane 1b of the end face tooth pushes the inclined plane 35b of the end face tooth of the gearbox power take-off shaft 35, so that the gearbox power take-off shaft 35 generates circumferential force Ft, the gearbox power take-off shaft 35 rotates relative to the coupling sleeve 1, and the end face tooth of the coupling sleeve 1 can be smoothly inserted into the end face tooth groove of the gearbox power take-off shaft 35 to realize matched connection.

In the above-mentioned process of engaging gear, the inclined plane that combines cover 1 and the terminal surface tooth that the gearbox took out force axle 35 corresponds can contact the laminating, in order to guarantee that combine cover 1 can continue the slip and realize complete engagement, the thrust along the inclined plane should be greater than the frictional force that the inclined plane produced this moment, namely: fcos alpha > mu Fsin alpha, the angle of the bevel should be guaranteed to be alpha < arctan (1/mu). Wherein mu is the friction coefficient of the bevel face bevel gear.

In the heavy load operation power taking process, as shown in fig. 6, when the engine rotation speed is reduced to a certain rotation speed, that is, when the rotation speed n2 of the transmission power taking shaft 35 is smaller than the rotation speed n1 of the coupling sleeve 1, the inclined plane 1b of the end face tooth of the coupling sleeve 1 is kept attached to the inclined plane 35b of the end face tooth of the transmission power taking shaft, and as the coupling sleeve 1 is subjected to the action of the torque M, the stress of the inclined plane 1b of the end face tooth of the coupling sleeve 1 is as follows:

bevel pressure: fn=fsinα+m/Rcos α

Component force along the inclined plane: M/Rsin alpha > (Fcos alpha+mu Fn)

Wherein R is the radius of the bond bush 1.

At this time, the inclined plane 1b of the end face tooth of the coupling sleeve 1 moves rightward relative to the inclined plane 35b of the end face tooth of the transmission power take-off shaft 35 until the coupling sleeve 1 is disengaged from the transmission power take-off shaft 35, and the torque of the coupling sleeve 1 is not transmitted to the transmission power take-off shaft 35, so that the engine is not reversely dragged.

The utility model is particularly used as follows:

as shown in fig. 1, the power take-off is in the disengaged position. The piston 16 is attached to the limit surface of the cylinder head 18 by the return spring 12. The cylinder shaft 7 is at the rightmost position, the coupling sleeve 1 is disconnected from the transmission power take-off shaft 35, and the return spring 12 is at the minimum potential energy state.

When the gear is shifted from the gear-releasing position to the gear-engaging position, high-pressure gas enters the power-taking cylinder 11 through the air inlet hole 14, and the piston 16 drives the cylinder shaft 7 to move leftwards and axially under the action of the high-pressure gas, so that the combined sleeve 1 is pushed to move leftwards; the inclined plane 1b of the combination sleeve 1 pushes the inclined plane 35b of the transmission power take-off shaft 35 to enable the transmission power take-off shaft 35 to generate circumferential force, and the transmission power take-off shaft 35 rotates relative to the combination sleeve 1 until the end face teeth of the combination sleeve 1 are completely inserted into the end face tooth grooves of the transmission power take-off shaft 35. After the combination sleeve 1 is matched and connected with the transmission power take-off shaft 35, the displacement sensor 20 detects the position of the cylinder shaft 7 in real time to judge whether the cylinder shaft reaches the power take-off position completely or not so as to realize complete gear engagement; after gear engagement, the power takeoff starts to transmit torque, the plane 35c of the end face teeth of the transmission power takeoff shaft 35 pushes the end face tooth plane 1c of the combining sleeve 1 to drive the combining sleeve 1 to rotate, the combining sleeve 1 drives the input gear 5 to rotate, and the input gear 5 transmits power to the output gear 30. During the movement of the piston 16 to the left, the gas in the left chamber is expelled through the breathing holes 9. The return spring 12 is always in a compressed state under the action of the piston 16, and the elastic potential energy increases.

As shown in fig. 2, the power take-off is in the engaged position. When the power take-off is in the gear position, the air inlet hole 14 is required to be always filled with high-pressure air, and the engagement of the end faces of the combining sleeve 1 and the power take-off shaft 35 of the gearbox is kept. At this time, the elastic potential energy of the return spring 12 is at a maximum state.

When the power take-off is out of gear, the high-pressure gas of the air inlet hole 14 is cut off, the right side pressure of the piston 16 disappears, and the compressed return spring 12 begins to rebound to push the piston 16 to move rightwards until the piston is attached to the limiting surface of the cylinder cover 18. The cylinder shaft 7 drives the combining sleeve 1 to exit from the meshed connection state with the transmission power take-off shaft 35. The displacement sensor 20 detects the position of the cylinder shaft 7 in real time to judge whether the gear is completely disengaged from the power take-off position or not to realize gear disengagement. During the rightward movement of the piston 16, the left chamber may be replenished with gas through the breathing holes 9 and the gas in the right chamber may be exhausted through the intake holes 14.

The utility model adopts the cylinder-driven direct-pushing type gear engaging mechanism, can avoid the problem of loose shifting fork and clamping stagnation existing in the traditional shifting fork type gear engaging structure, and simultaneously simplifies the gear engaging structure; the gear engaging structure is a combined sleeve, an end face bevel gear structure is adopted, the arc end face of the end face gear cannot be provided with tooth top teeth during gear engaging, and the inclined surface of the combined sleeve pushes the inclined surface of the power take-off shaft of the gearbox, so that the gear engaging success rate can be improved; meanwhile, the power connection can be cut off by the structure of the power takeoff during heavy load, and the engine cannot be reversely towed; in addition, by adopting the non-contact Hall displacement sensor, the problems of abrasion and clamping stagnation of contacts of the mechanical contact switch can be avoided, and the detection accuracy is improved.

Claims

1. The power takeoff comprises a power takeoff shell, wherein an input gear and an output gear which are meshed and driven are arranged in the power takeoff shell, and the input gear is provided with a through center hole; the power take-off device is characterized in that a power take-off cylinder is arranged on one side of the power take-off device shell, and a cylinder shaft of the power take-off cylinder vertically extends into the power take-off device shell; a combining sleeve is arranged in the central hole of the input gear, the peripheral side of the combining sleeve is in circumferential limit connection with the central hole of the input gear, one end of the combining sleeve extends out of the power takeoff shell, the extending end of the combining sleeve is in meshed connection with a power take-off shaft of the gearbox through an end face tooth structure, and the power take-off shaft of the gearbox is linked with the combining sleeve to drive the input gear to rotate during meshed connection; the cylinder shaft stretches into the inside of the combining sleeve and is in axial limiting connection with the combining sleeve, and when the cylinder shaft moves, the cylinder shaft drives the combining sleeve to axially move so as to realize connection and disconnection of the combining sleeve and the power take-off shaft of the gearbox.

2. The power takeoff of claim 1, wherein a piston is arranged in the power takeoff cylinder, and a breathing hole and an air inlet hole are respectively arranged on two sides of the piston of the power takeoff cylinder; the cylinder shaft is fixedly connected with the piston, a return spring is sleeved outside the cylinder shaft, and the return spring is arranged in the spring seat and is abutted between the spring seat and the piston; when the combination sleeve is in meshed connection with the transmission power taking shaft, the air inlet hole keeps high-pressure air inlet, and the return spring is compressed to the position of maximum elastic potential energy; when the combining sleeve is disconnected with the power take-off shaft of the gearbox, the air inlet is cut off, and the return spring drives the piston and the cylinder shaft to move and return.

3. The power takeoff of claim 2, wherein a displacement sensor for detecting the position of a cylinder shaft is mounted at the outer end of the power takeoff cylinder, the displacement sensor comprises a fixedly arranged sensing hole and a moving shaft arranged outside the piston, and the piston drives the moving shaft to move back and forth in the sensing hole.

4. The power takeoff of claim 1, wherein the end faces of the coupling sleeve and the transmission power take-off shaft are provided with end face teeth, and tooth faces of the end face teeth comprise a plane, an arc end face and an inclined plane; when the combination sleeve is driven by the cylinder shaft to be meshed with the transmission power take-off shaft, the inclined planes of the two end face teeth are in fit interaction with the inclined planes, and the combination sleeve and the transmission power take-off shaft rotate relatively; the plane of the end face teeth of the engaged combined sleeve and the transmission power take-off shaft are jointed with the plane to transfer torque.

5. The power take-off of claim 4, wherein the coupling sleeve automatically slides out of engagement along the face tooth bevel under torque when the rotational speed of the transmission power take-off shaft decreases, the coupling sleeve automatically disconnecting from the transmission power take-off shaft.

6. The power takeoff of claim 1, wherein the input gear is connected to the coupling sleeve by a spline fit, maintaining synchronous rotation; the coupling sleeve slides axially along the splined bore of the input gear.

7. The power takeoff of claim 1, wherein an inner hole is formed in the middle of the combining sleeve, the cylinder shaft is in rotary connection with the inner hole of the combining sleeve through the matching of a bearing bush, and gaskets and clamping springs for axial limiting are arranged on two sides of the bearing bush; the coupling sleeve and the cylinder shaft are kept to axially and synchronously move.