CN110864079A

CN110864079A - Worm gear box for land leveler and land leveler

Info

Publication number: CN110864079A
Application number: CN201911278497.2A
Authority: CN
Inventors: 王明燕; 侯志强; 刘汉光
Original assignee: Jiangsu Xugong Construction Machinery Research Institute Co ltd
Current assignee: Jiangsu Xugong Construction Machinery Research Institute Co ltd
Priority date: 2019-12-13
Filing date: 2019-12-13
Publication date: 2020-03-06

Abstract

The present disclosure relates to a worm gear box for land leveller for transmitting the power of a motor to a rotary gear controlling the rotation angle of a scraper knife, comprising: a box body; the worm is rotatably arranged in the box body, and the first end of the worm is in power connection with the motor; the worm wheel is rotatably arranged in the box body and does not self-lock in the process of meshing transmission with the worm; one end of the output shaft is in transmission connection with the worm wheel, and the other end of the output shaft is in power connection with the rotary gear; and the braking device is arranged at the second end of the worm, can selectively brake the worm and can bear the impact load transmitted to the worm wheel by the rotary gear. The embodiment of the application has the advantages of strong self-locking capacity and high transmission efficiency, and the braking device has the advantages of small occupied space, weaker part abrasion degree and long service life.

Description

Worm gear box for land leveler and land leveler

Technical Field

The disclosure relates to the field of engineering machinery, in particular to a worm gear box for a land leveler and the land leveler.

Background

When the grader levels a road surface, the rotary ring for controlling the rotary angle of the scraper knife is fixed, the scraper knife keeps a certain angle to level the road surface, and at the moment, the worm gear box needs a braking device to lock the scraper knife. And required power is provided by the worm gear case when the cutting blade of leveler gyration, therefore the leveler is at the in-process of marcing, and when the cutting blade bore great impact, impact load probably constitutes the damage via the drive mechanism of leveler to the gear drive of worm gear incasement or worm gear drive, therefore the worm gear case need be equipped with and prevents that the too big protector of worm gear impact.

For impact load, most of the existing schemes use the self-locking characteristic of a worm gear pair to realize the self-locking of the shovel blade, but the self-locking torque and the transmission efficiency of the worm gear pair are a pair of spear shields, and the transmission efficiency of the worm gear pair with self-locking capability also drops greatly, so that the transmission efficiency of a worm gear box is extremely low, the heat productivity is extremely high, and the torque transmitted to the shovel blade is also greatly reduced.

Based on this, more and more customers require that the land leveler can realize the area and carry gyration, and this just requires worm gear case auto-lock reliable the time, and transmission efficiency will promote by a wide margin. The related protective device is arranged on the worm wheel and the output shaft and is used for preventing the impact of the scraper knife from damaging the worm wheel and the worm, but the torque acting on the worm wheel is large, and the protective device needs to provide large protective torque, so that the friction plate is frequently abraded seriously, and the friction plate needs to be frequently replaced. Some of the guards also use hydraulic motors to brake, but this complicates the hydraulic system and increases the torque and impact forces carried by the hydraulic motors.

Disclosure of Invention

In view of this, the embodiment of the present disclosure provides a worm gear box for a land leveler and a land leveler, which have the advantages of strong self-locking capability, high transmission efficiency, small occupied space of a braking device, weak degree of component wear, and long service life.

In one aspect of the present disclosure, there is provided a worm gear box for a grader for transmitting power of a motor to a rotary gear controlling a rotation angle of a blade, comprising:

a box body;

the worm is rotatably arranged in the box body, and the first end of the worm is in power connection with the motor;

the worm wheel is rotatably arranged in the box body and does not generate self-locking in the process of meshing transmission with the worm;

one end of the output shaft is in transmission connection with the worm wheel, and the other end of the output shaft is in power connection with the rotary gear; and

and the braking device is arranged at the second end of the worm, can selectively brake the worm and can bear the impact load transmitted to the worm wheel by the rotary gear.

In some embodiments, the braking device comprises:

the friction plate set comprises a plurality of moving plates which can rotate along with the worm and a plurality of static plates which do not rotate along with the worm, and the moving plates and the static plates can rub with each other on a plane vertical to the axial direction of the worm; and

and the pressure regulating assembly can regulate the pressure between the plurality of moving plates and the plurality of static plates along the axial direction of the worm so as to change the friction force between the plurality of moving plates and the plurality of static plates.

In some embodiments, the plurality of rotor plates are sleeved on the outer peripheral surface of the second end of the worm and are fixed relative to the worm in the circumferential direction through splines; the plurality of static sheets are sleeved on the periphery of the worm, fixedly arranged in the box body and alternately attached to the plurality of moving sheets by taking the worm as an axis.

In some embodiments, the worm gear case further comprises:

the first end cover is detachably connected to the box body, is positioned on the outer side of the second end of the worm, and is provided with a mounting seat on one side close to the worm;

the pressure regulating subassembly includes:

the spring is arranged in the mounting seat, and the first end of the spring is abutted against the bottom of the mounting seat; and

the sliding block is arranged between the spring and the friction plate set in a sliding mode along the axial direction of the worm and is abutted against the second end of the spring, and the sliding block can tightly abut against the pressure regulating assembly under the elastic force action of the spring.

In some embodiments, the slider is provided with a first step along an outer side wall of the worm, the inner wall of the box body is provided with a second step corresponding to the first step, the first step and the second step are matched with each other in a radial direction of the worm, and the first step and the second step have a gap in an axial direction of the worm, and the gap enables a synthetic oil cavity to be enclosed between the first step and the second step.

In some embodiments, the voltage regulation assembly comprises:

the first sealing ring is arranged between the outer side wall of the sliding block and the inner wall of the box body and is positioned on one side, close to the first end cover, of the oil cavity along the axial direction of the worm; and

and the second sealing ring is arranged between the outer side wall of the sliding block and the inner wall of the box body and is positioned on one side of the oil cavity far away from the first end cover along the axial direction of the worm.

In some embodiments, the box body is provided with an oil hole, and the oil hole is communicated with the oil cavity, so that the oil cavity can change the volume of the oil cavity under the action of a pressure oil source, and further the sliding block is driven to slide along the axial direction of the worm.

In some embodiments, a wall surface of the oil chamber on a side close to the first end cover is formed by a wall surface on the slider, and a wall surface of the oil chamber on a side far from the first end cover is formed by a wall surface on the case, so that the slider can slide relative to the case toward a side of the first end cover when the volume of the oil chamber changes.

In some embodiments, the outer surface of the first end of the worm is provided with external splines, and the worm gear case further comprises:

the coupling is connected to the first end of the worm, and the inner surface of the coupling is provided with an internal spline and is used for being matched with an external spline at the first end of the worm to transmit torque;

and the pin is clamped between the coupler and the worm and used for limiting the coupler in the axial direction of the worm.

In some embodiments, the worm gear case further comprises:

the second end cover is detachably connected to the box body, is positioned on the outer side of the first end of the worm and is provided with a through hole along the axial direction of the worm so that the output shaft of the motor can penetrate through the through hole and is connected to the coupler; and

and the third sealing ring is arranged between the second end cover and the box body.

In some embodiments, the worm gear case further comprises:

the first bearing is supported between the first end and the second end cover of the worm, and is limited relative to the axial direction of the worm by a first shaft collar at the first end of the worm and a first positioning step at the inner side of the second end cover;

the second bearing is supported between the second end of the worm and the box body, and is limited axially relative to the worm by a second collar at the second end of the worm and a second positioning ladder at the inner side of the box body; and

and the adjusting gasket is arranged between the second end cover and the box body and used for adjusting the position of the second end cover relative to the box body along the axial direction of the worm.

In one aspect of the disclosure, a grader is provided including a worm gear box as in any of the preceding embodiments.

Therefore, according to the embodiment of the disclosure, the worm gear box does not use the self-locking function of the worm gear, so that the transmission efficiency of the worm gear is improved, the revolving torque of the scraper knife is increased, the use requirement of heavy-load revolving of a client is met, and the operation efficiency is improved; in addition, as the transmission efficiency of the worm gear case is improved, the heat productivity of the worm gear case is reduced, and the service lives of transmission lubricating oil and a worm gear case sealing element are prolonged; in addition, the braking device is arranged on the worm, and the torque borne by the worm is many times smaller than that of the worm wheel, so that the space installation requirement of the braking device is reduced, the braking torque is reduced, the abrasion rate of the friction plate can be effectively reduced, and when the impact force of the scraper knife exceeds the pretightening force of the spring, the friction plate of the braking device begins to slip, so that the damage of the tooth surface of the worm wheel and the worm, caused by the impact of the scraper knife, to the worm wheel and the worm is prevented.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and together with the description, serve to explain the principles of the disclosure.

The present disclosure may be more clearly understood from the following detailed description, taken with reference to the accompanying drawings, in which:

FIG. 1 is a schematic cross-sectional structural view of a worm gear case according to some embodiments of the present disclosure;

FIG. 2 is a schematic diagram of a portion of a brake in a worm gear box according to some embodiments of the present disclosure.

In the figure:

1. the oil-gas clutch comprises a box body, 11, oil holes, 12, a second positioning step, 2, a worm, 21, a first collar, 22, a second collar, 3, a worm wheel, 4, an output shaft, 5, a braking device, 51, a friction plate group, 511, a movable plate, 512, a fixed plate, 52, a pressure regulating assembly, 521, a spring, 522, a sliding block, 523, an oil cavity, 524, a first sealing ring, 525, a second sealing ring, 6, a first end cover, 61, a mounting seat, 71, a coupling, 72, a pin, 81, a second end cover, 811, a first positioning step, 82, a third sealing ring, 91, a first bearing, 92, a second bearing, 93 and an adjusting gasket.

It should be understood that the dimensions of the various parts shown in the figures are not drawn to scale. Further, the same or similar reference numerals denote the same or similar components.

Detailed Description

Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the disclosure, its application, or uses. The present disclosure may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art. It should be noted that: the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values set forth in these embodiments are to be construed as merely illustrative, and not as limitative, unless specifically stated otherwise.

The use of "first," "second," and similar terms in this disclosure is not intended to indicate any order, quantity, or importance, but rather are used to distinguish one element from another. The word "comprising" or "comprises", and the like, means that the element preceding the word covers the element listed after the word, and does not exclude the possibility that other elements are also covered. "upper", "lower", "left", "right", and the like are used merely to indicate relative positional relationships, and when the absolute position of the object being described is changed, the relative positional relationships may also be changed accordingly.

In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be intervening devices between the specific device and the first device or the second device. When a particular device is described as being coupled to other devices, that particular device may be directly coupled to the other devices without intervening devices or may be directly coupled to the other devices with intervening devices.

All terms (including technical or scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs unless specifically defined otherwise. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

As shown in FIGS. 1-2:

a box body 1;

the worm 2 is rotatably arranged in the box body 1, and the first end of the worm is in power connection with the motor;

the worm wheel 3 is rotatably arranged in the box body 1 and does not self-lock in the process of meshing transmission with the worm 2;

one end of the output shaft 4 is connected with the worm wheel 3 in a transmission way, and the other end of the output shaft is connected with the rotary gear in a power way; and

and a braking device 5 which is arranged at the second end of the worm 2, can selectively brake the worm 2 and can bear the impact load transmitted to the worm wheel 3 by the rotary gear.

The worm wheel 3 and the worm 2 do not self-lock in the meshing transmission process in the disclosure, which means that when the worm 2 stops rotating, the worm wheel 3 rotates and cannot enable the worm 2 to reversely rotate. The condition that worm wheel 3 and worm 2 reach the auto-lock is that the expansion helix angle of worm 2 is less than the friction angle of worm wheel 3 worm 2 contact, and does not take place the auto-lock between worm wheel 3 in this disclosure and the worm 2, and the transmission efficiency of worm wheel 3 worm 2 pair is higher for taking place the worm wheel 3 worm 2 of auto-lock this moment for the turning moment of spiller is corresponding to be increased, satisfies the user demand that the customer takes heavy load gyration, promotes the operating efficiency. In addition, as the transmission efficiency of the worm gear case is improved, the heat productivity of the worm gear case is reduced, and the service life of transmission lubricating oil and the service life of a worm gear case sealing element are prolonged.

Since the worm wheel 3 and the worm 2 cannot be self-locked in the present disclosure, the worm 2 is braked by providing the brake device 5 at the second end of the worm 2. Since the torque borne by the worm 2 is many times smaller than that of the worm wheel 3, the space installation requirement of the braking device 5 in the disclosure is lower, the braking torque is also lower, and further, the abrasion rate of the braking device 5 can be effectively reduced.

And the arresting gear 5 in this application can bear the impact load that transmits to worm wheel 3 by the slewing gear, and arresting gear 5 and protector integration promptly for when the slewing gear of leveler received great impact load, can be born impact load by arresting gear 5, prevent that worm wheel 3 worm 2 from receiving the damage of worm wheel 3 worm 2 flank that the impact of spiller arouses.

Further, in order to achieve selective braking of the worm 2 by the braking device 5, in some embodiments, the braking device 5 comprises:

the friction plate group 51 comprises a plurality of moving plates 511 which can rotate along with the worm 2 and a plurality of static plates 512 which do not rotate along with the worm 2, and the plurality of moving plates 511 and the plurality of static plates 512 can rub against each other in a plane perpendicular to the axial direction of the worm 2; and

the pressure adjusting assembly 52 is capable of adjusting the pressure between the plurality of moving plates 511 and the plurality of static plates 512 along the axial direction of the worm 2 to change the friction force between the plurality of moving plates 511 and the plurality of static plates 512.

Based on the cooperation of the friction plate set 51 and the pressure regulating assembly 52, the present disclosure can adjust the pressure applied between the plurality of moving plates 511 and the plurality of static plates 512 in the friction plate set 51 through the pressure regulating assembly 52, and change the friction force in the friction plate set 51: when the worm 2 needs to be braked, the friction force of the friction plate set 51 is increased, and the braking torque is transmitted to the worm 2 through the plurality of movable plates 511 rotating along with the worm 2, so that the worm 2 is static relative to the area of the box body 1; when the worm 2 is not required to be braked, the friction force of the friction plate set 51 is reduced, so that the movable plate 511 and the fixed plate 512 can relatively rotate, and further, the brake torque is not generated on the rotation of the worm 2.

Further, in order to realize that the rotor 511 and the worm 2 can transmit rotation torque, and in order that the stator 512 does not rotate along with the worm 2, in some embodiments, a plurality of rotors 511 are sleeved on the outer peripheral surface of the second end of the worm 2, and are fixed relative to the worm 2 in the circumferential direction through splines; the plurality of static blades 512 are sleeved on the periphery of the worm 2, are fixedly arranged on the box body 1, and are alternately attached to the plurality of moving blades 511 by taking the worm 2 as an axis.

Further, in order to enable the pressure of the pressure regulating assembly 52 to act on the friction plate set 51 in the direction along the axis of the worm 2, in some embodiments, the worm gear box further includes:

the first end cover 6 is detachably connected to the box body 1, is positioned on the outer side of the second end of the worm 2, and is provided with a mounting seat 61 on one side close to the worm 2;

the pressure regulating assembly 52 includes:

a spring 521, which is disposed in the mounting seat 61 and has a first end abutting against the bottom of the mounting seat 61; and

the slider 522 is slidably disposed between the spring 521 and the friction plate set 51 along the axial direction of the worm 2, abuts against the second end of the spring 521, and can abut against the pressure regulating assembly 52 under the elastic force of the spring 521.

The spring 521 is preset in a compressed state, so that the sliding block 522 abutting against the spring 521 can abut against the friction plate set 51 along the direction of the axis of the worm 2, so as to provide a preset pressure for the friction plate set 51, and further, the worm 2 is in a braking state. The spring 521 is not limited to the form of the coil spring 521, and other forms such as the belleville spring 521 and the diaphragm spring 521 that can provide the elastic force may be used.

Based on the pretightening force of the spring 521, when the impact force applied to the worm 2 when the rotary gear of the land scraper is subjected to the impact load exceeds the pretightening force of the spring 521, the friction plate of the braking device 5 starts to slip and absorbs the impact load through heat generated by friction, so that the impact load is not further transmitted to the worm 2, and the damage of the tooth surface of the worm wheel 3 and the worm 2 caused by the impact of the scraper knife on the worm wheel 3 and the worm 2 is prevented.

Further, in order to make the pressure provided by the pressure adjusting assembly 52 to the friction plate set 51 adjustable, in some embodiments, the sliding block 522 is provided with a first step along the outer side wall of the worm 2, the inner wall of the box body 1 is provided with a second step corresponding to the first step, the first step and the second step are mutually matched in the radial direction of the worm 2, the first step and the second step have a gap in the axial direction of the worm 2, and the gap enables a synthetic oil cavity 523 to be enclosed between the first step and the second step.

The box body 1 is provided with an oil hole 11, and the oil hole 11 is communicated with the oil chamber 523, so that the oil chamber 523 can change the volume thereof under the action of a pressure oil source, and further the slide block 522 is driven to slide along the axial direction of the worm 2.

Based on the setting of the oil chamber 523, the state control process of the pressure regulating assembly 52 to the braking device 5 is as follows:

when the oil chamber 523 is not filled with oil, the pre-tightened spring 521 presses the end surface on one side of the sliding block 522, so that the end surface on the other side of the sliding block 522 presses the static plate 512 in the friction plate set 51, the static plate 512 and the adjacent moving plate 511 generate friction force, the pressure is transmitted to the subsequent static plate 512 and moving plate 511 through the adjacent moving plate 511, the friction force generated by the friction plate set 51 as a whole is finally transmitted to the worm 2 as braking torque through the spline, and therefore when the pre-tightening force of the spring 521 is large enough, the worm wheel 3 and the worm 2 are in a locked state;

when the oil hole 11 is filled with pressure oil, hydraulic oil enters an oil cavity 523 formed by the first step and the second step, positive pressure generated by the hydraulic oil pushes the slider 522 to move along the axial direction of the worm 2, the positive pressure generated during the movement of the slider 522 is opposite to the acting force of the spring 521, the spring 521 is pushed to be compressed continuously, so that the pressure between the moving plate 511 and the static plate 512 is reduced, the gap is enlarged, and when the pressure is low enough or the gap is large enough, the moving plate 511 and the static plate 512 are in a separated state, the friction force inside the friction plate group 51 is relieved, and the worm wheel 3 and the worm 2 are in a brake relieving state.

Further, in order to achieve a good seal of the oil chamber 523 and prevent leakage of the pressure oil, in some embodiments, the pressure regulating assembly 52 includes:

a first sealing ring 524, which is arranged between the outer side wall of the sliding block 522 and the inner wall of the box body 1, and is located on one side of the oil chamber 523 close to the first end cover 6 along the axial direction of the worm 2; and

and a second sealing ring 525 which is arranged between the outer side wall of the sliding block 522 and the inner wall of the box body 1 and is positioned on one side of the oil chamber 523 far away from the first end cover 6 along the axial direction of the worm 2.

Further, in order to limit the moving direction of the slider 522 to the side of the spring 521, in some embodiments, a wall surface of the oil chamber 523 on the side close to the first end cover 6 is formed by a wall surface on the slider 522, and a wall surface of the oil chamber 523 on the side far from the first end cover 6 is formed by a wall surface on the box body 1, so that when the volume of the oil chamber 523 is changed, the slider 522 can slide relative to the box body 1 to the side of the first end cover 6.

Because the oil chamber 523 forms a fit relationship between two sidewalls perpendicular to the worm radial direction, the distance is not variable in the process of changing the volume of the oil chamber 523; two side walls of the oil chamber 523 perpendicular to the axial direction of the worm are respectively located on the slider 522 and the box body 1, and a gap is formed between the two side walls perpendicular to the axial direction of the worm, and the slider 522 is slidable in the axial direction of the worm relative to the box body 1, so that when the volume of the oil chamber 523 changes, the distance between the two side walls perpendicular to the axial direction of the worm changes, and the slider 522 is further pushed to slide relative to the box body 1.

In particular, since the wall surface of the oil chamber 523 on the side close to the first end cover 6 is formed by the wall surface on the slider 522, the wall surface of the oil chamber 523 on the side far from the first end cover 6 is formed by the wall surface on the case 1, and the case 1 is not movable, when the volume of the oil chamber 523 is changed, the sliding direction of the slider 522 is limited to slide toward the side of the first end cover 6 with respect to the case 1.

Further, in order to realize the power connection between the worm 2 and the motor, in some embodiments, the outer surface of the first end of the worm 2 is provided with external splines, and the worm gear box further includes:

the coupler 71 is connected to the first end of the worm 2, and the inner surface of the coupler 71 is provided with an internal spline and is used for being matched with an external spline at the first end of the worm 2 to transmit torque;

and the pin 72 is clamped between the coupler 71 and the worm 2 and used for limiting the coupler 71 in the axial direction of the worm 2.

Further, in order to prevent oil leakage and foreign matter intrusion in the worm gear case, in some embodiments, the worm gear case further includes:

a second end cap 81 detachably connected to the case 1, located outside the first end of the worm 2, and having a through hole along the axial direction of the worm 2, so that the output shaft 4 of the motor can pass through the through hole and be connected to the coupling 71; and

and a third packing 82 provided between the second end cap 81 and the case 1.

Further, in order to rotatably mount the worm 2 inside the casing 1 and perform reasonable axial limitation on the worm 2, in some embodiments, the worm gear case further includes:

a first bearing 91 supported between the first end of the worm 2 and the second end cap 81 and limited in the axial direction of the worm 2 by a first collar 21 at the first end of the worm 2 and a first positioning step 811 inside the second end cap 81;

a second bearing 92 supported between the second end of the worm 2 and the box body 1, and limited axially relative to the worm 2 by a second collar 22 at the second end of the worm 2 and a second positioning step 12 inside the box body 1; and

and an adjusting shim 93, which is arranged between the second end cover 81 and the box body 1 and is used for adjusting the position of the second end cover 81 relative to the box body 1 along the axial direction of the worm 2.

The axial positioning of the worm 2 depends on the two bearings on both sides of the worm 2, so the axial limit of the first bearing 91 and the second bearing 92 directly affects the mounting accuracy of the worm 2 in the axial direction. The second bearing 92 is limited by the box body 1, the first bearing 91 is limited by the second end cover 81, and therefore the relative position of the box body 1 and the second end cover 81 along the axial direction of the worm 2 is transmitted to the installation precision of the worm 2 in the axial direction. Based on this, the present disclosure adjusts the position of the second end cover 81 relative to the box body 1 along the axial direction of the worm 2 by the adjusting shim 93 arranged between the second end cover 81 and the box body 1, so that the influence of the error of the box body 1, the worm 2 or the second end cover 81 in the machining process on the installation and the positioning of the worm 2 can be avoided by changing the number and/or the specification of the adjusting shim 93.

Further, in one aspect of the present disclosure, a grader is provided that includes a worm gear box as in any of the preceding embodiments.

Therefore, according to the embodiment of the disclosure, the worm gear case does not use the self-locking function of the worm wheel 3 and the worm 2, so that the transmission efficiency of the worm wheel 3 and the worm 2 is improved, the revolving torque of the shovel blade is increased, the use requirement of heavy-load revolving of a client is met, and the operation efficiency is improved; in addition, as the transmission efficiency of the worm gear case is improved, the heat productivity of the worm gear case is reduced, and the service lives of transmission lubricating oil and a worm gear case sealing element are prolonged; in addition, the braking device 5 is arranged on the worm 2, and the torque borne by the worm 2 is many times smaller than that of the worm wheel 3, so that the space installation requirement of the braking device 5 is reduced, the braking torque is reduced, the abrasion rate of the friction plate can be effectively reduced, and when the impact force of the scraper knife exceeds the pretightening force of the spring 521, the friction plate of the braking device 5 starts to slip, so that the damage to the tooth surface of the worm wheel 3 and the worm 2 caused by the impact of the scraper knife to the worm wheel 3 and the worm 2 is prevented.

Thus, various embodiments of the present disclosure have been described in detail. Some details that are well known in the art have not been described in order to avoid obscuring the concepts of the present disclosure. It will be fully apparent to those skilled in the art from the foregoing description how to practice the presently disclosed embodiments.

Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the foregoing examples are for purposes of illustration only and are not intended to limit the scope of the present disclosure. It will be understood by those skilled in the art that various changes may be made in the above embodiments or equivalents may be substituted for elements thereof without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A worm gear box for a land leveler for transmitting power of a motor to a rotary gear for controlling a rotation angle of a blade, comprising:

a box body (1);

the worm (2) is rotatably arranged in the box body (1), and the first end of the worm is in power connection with the motor;

the worm wheel (3) is rotatably arranged in the box body (1) and does not self-lock in the process of meshing transmission with the worm (2);

one end of the output shaft (4) is connected with the worm wheel (3) in a transmission way, and the other end of the output shaft is connected with the rotary gear in a power way; and

and the braking device (5) is arranged at the second end of the worm (2), can selectively brake the worm (2), and can bear the impact load transmitted to the worm wheel (3) by the rotary gear.

2. Worm-gear case according to claim 1, characterized in that the braking device (5) comprises:

a friction plate group (51) which comprises a plurality of moving plates (511) capable of rotating with the worm (2) and a plurality of static plates (512) not capable of rotating with the worm (2), wherein the plurality of moving plates (511) and the plurality of static plates (512) can rub against each other in a plane perpendicular to the axial direction of the worm (2); and

and the pressure regulating assembly (52) can regulate the pressure between the plurality of moving plates (511) and the plurality of static plates (512) along the axial direction of the worm (2) so as to change the friction force between the plurality of moving plates (511) and the plurality of static plates (512).

3. The worm-gear case as claimed in claim 2, characterized in that the plurality of moving plates (511) are sleeved on the outer peripheral surface of the second end of the worm (2) and are fixed relative to the worm (2) in the circumferential direction through splines; the plurality of static sheets (512) are sleeved on the periphery of the worm (2), fixedly arranged on the box body (1), and alternately attached to the plurality of moving sheets (511) by taking the worm (2) as an axis.

4. The worm-gear case according to claim 2, further comprising:

the first end cover (6) is detachably connected to the box body (1), is positioned on the outer side of the second end of the worm (2), and is provided with a mounting seat (61) on one side close to the worm (2);

the pressure regulating assembly (52) includes:

the spring (521) is arranged in the mounting seat (61), and a first end of the spring abuts against the bottom of the mounting seat (61); and

and the sliding block (522) is arranged between the spring (521) and the friction plate group (51) in a sliding manner along the axial direction of the worm (2), abuts against the second end of the spring (521), and can abut against the pressure regulating assembly (52) under the action of the elastic force of the spring (521).

5. The worm-gear case as claimed in claim 4, characterized in that the slider (522) is provided with a first step along the outer side wall of the worm (2), the inner wall of the case (1) is provided with a second step corresponding to the first step, the first step and the second step are mutually engaged in the radial direction of the worm (2), and the first step and the second step have a clearance in the axial direction of the worm (2), and the clearance is such that a synthetic oil chamber (523) is enclosed between the first step and the second step.

6. The worm-gear case according to claim 5, characterized in that the pressure regulating assembly (52) comprises:

a first sealing ring (524) arranged between the outer side wall of the sliding block (522) and the inner wall of the box body (1) and positioned on one side of the oil chamber (523) close to the first end cover (6) along the axial direction of the worm (2); and

and the second sealing ring (525) is arranged between the outer side wall of the sliding block (522) and the inner wall of the box body (1) and is positioned on one side, far away from the first end cover (6), of the oil cavity (523) along the axial direction of the worm (2).

7. The worm-gear case as claimed in claim 5, characterized in that the case body (1) is provided with an oil hole (11), and the oil hole (11) is communicated with the oil chamber (523) so that the oil chamber (523) can change its volume under the action of a pressure oil source to drive the sliding block (522) to slide along the axial direction of the worm (2).

8. The worm-gear case according to claim 5, characterized in that a wall surface of the oil chamber (523) on a side close to the first end cover (6) is formed by a wall surface on the slider (522), and a wall surface of the oil chamber (523) on a side far from the first end cover (6) is formed by a wall surface on the case (1), so that the slider (522) can slide relative to the case (1) toward a side of the first end cover (6) when the volume of the oil chamber (523) is changed.

9. The worm-gear case according to claim 1, characterized in that the outer surface of the first end of the worm (2) is provided with external splines, the worm-gear case further comprising:

the coupling (71) is connected to the first end of the worm (2), and the inner surface of the coupling is provided with an internal spline and is used for being matched with an external spline at the first end of the worm (2) to transmit torque;

and the pin (72) is clamped between the coupler (71) and the worm (2) and used for limiting the axial direction of the worm (2) of the coupler (71).

10. The worm-gear case according to claim 9, further comprising:

the second end cover (81) is detachably connected to the box body (1), is positioned on the outer side of the first end of the worm (2), and is provided with a through hole along the axial direction of the worm (2) so that the output shaft (4) of the motor can penetrate through the through hole and is connected to the coupler (71); and

and the third sealing ring (82) is arranged between the second end cover (81) and the box body (1).

11. The worm-gear case according to claim 10, further comprising:

a first bearing (91) supported between the first end of the worm (2) and the second end cover (81) and limited axially relative to the worm (2) by a first collar (21) at the first end of the worm (2) and a first positioning step (811) inside the second end cover (81);

a second bearing (92) supported between the second end of the worm (2) and the box body (1) and limited axially relative to the worm (2) by a second collar (22) at the second end of the worm (2) and a second positioning step (12) inside the box body (1); and

and the adjusting gasket (93) is arranged between the second end cover (81) and the box body (1) and is used for adjusting the position of the second end cover (81) relative to the box body (1) along the axial direction of the worm (2).

12. A grader comprising the worm gear case according to any of claims 1 to 11.