CN220748997U - Transmission device for engineering machinery - Google Patents

Abstract

The application discloses transmission that engineering machine tool used includes: the device comprises a main shaft, a transmission piece, a box body, an end cover, an oil seal and a positioning piece. Wherein, the transmission piece is coaxially and fixedly arranged on the main shaft; the box body is formed with an installation space and a perforation; the main shaft passes through the perforation to form rotary connection with the box body around a rotary axis; the end cover is fixedly arranged at one end of the box body; the inside of the end cover is provided with a mounting hole communicated with the mounting space; one end of the main shaft passes through the perforation and is inserted into the mounting hole; at least one oil seal is fixedly arranged in the mounting hole of the end cover; the oil seal and the main shaft are in rotary connection around a rotation axis; the oil seal is positioned between the main shaft and the end cover; the positioning piece is fixedly arranged in the mounting hole of the end cover; the end cover is provided with a limit part; the limiting part is positioned in the perforation; at least one oil seal is positioned between the limiting part and one positioning piece. The beneficial point of the application lies in: a transmission device for a construction machine is provided which reduces the possibility of leakage of lubricating oil by reducing axial play of an oil seal.

Description

Transmission device for engineering machinery

Technical Field

The application relates to the technical field of engineering machinery, in particular to a transmission device for engineering machinery.

Background

For a construction machine such as a drill carriage, a hydraulic drill carriage, or a mining machine, a transmission for outputting torque is generally provided. The box body of the transmission device is internally provided with transmission parts such as gears, pulleys, chain wheels and the like which are connected with power sources such as motors and hydraulic motors, the transmission parts are driven to rotate in a gear transmission mode, a chain transmission mode, a belt transmission mode and the like, and then the transmission parts drive a main shaft to rotate, so that torque is output to equipment such as a drill rod and the like connected with the main shaft. Lubricating oil is generally injected into the box body to lubricate transmission parts and the like in the box body. An oil seal is arranged between the box body and the main shaft to separate lubricating oil from the outside, but when the main shaft rotates at a high speed, the oil seal is easy to axially float, so that the oil seal and the main shaft are worn out to cause failure of the oil seal. The rotary power head for driving the drill rod to rotate on equipment such as a rock drilling rig and the like, namely the problem of serious axial movement of the oil seal exists.

In the related art, chinese patent publication No. CN103016005B discloses a driven wheel device and a shovel plate structure of a heading machine having the driven wheel device, which improves sealing performance by providing two double oil seals in contact with each other. However, the related art does not give any technical suggestion for how to solve the problem that the oil seal fails due to axial movement of the oil seal when the spindle rotates at a high speed.

Disclosure of Invention

The content of the present application is intended to introduce concepts in a simplified form that are further described below in the detailed description. The section of this application is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

To solve the technical problems mentioned in the background section above, some embodiments of the present application provide a transmission device for a construction machine, including: the device comprises a main shaft, a transmission piece, a box body, an end cover, an oil seal and a positioning piece. The transmission piece is used for being connected to a power source to rotate around a rotation axis under the driving of the power source; the transmission part is coaxially and fixedly arranged on the main shaft so as to drive the main shaft to rotate when rotating; the box body is provided with an installation space for placing the transmission part and a perforation penetrating through the installation space along the direction of the rotation axis; the main shaft passes through the perforation to form rotary connection with the box body around a rotary axis; the end cover is fixedly arranged at one end of the box body along the direction of the rotation axis; the inside of the end cover is provided with a mounting hole communicated with the mounting space; one end of the main shaft penetrates through the through hole along the direction of the rotation axis and is inserted into the mounting hole so that the main shaft is rotationally connected to the end cover around the rotation axis; at least one oil seal is fixedly arranged in the mounting hole of the end cover; the oil seal and the main shaft are in rotary connection around a rotation axis; the oil seal is positioned between the main shaft and the end cover to isolate the main shaft from the end cover and seal the installation space; the positioning piece is fixedly arranged in the mounting hole of the end cover; one end of the end cover along the direction of the rotation axis is provided with a limit part; the limiting part is positioned in the perforation; at least one oil seal is positioned between the limiting part and one positioning piece along the rotation axis direction.

Further, at least two oil seals are arranged in the mounting hole of the end cover along the direction of the rotation axis; at least one locating piece is arranged between two adjacent oil seals in the mounting hole.

Further, the positioning pieces are in one-to-one correspondence with the oil seals; each oil seal and each positioning piece are sequentially arranged in the direction of the rotation axis so as to limit the movement of each oil seal in the direction of the rotation axis through each positioning piece.

Further, the limiting part is arranged at one end of the end cover far away from the box body and is positioned in the mounting hole; an oil seal farthest from the case in the rotation axis direction is located between the limiting portion and a positioning member adjacent to the oil seal.

Further, the ratio of the minimum distance between the two adjacent positioning members in the rotation axis direction to the length of the oil seal between the two adjacent positioning members in the rotation axis direction is in the range of 1 to 1.2.

Further, the transmission device for the construction machine further includes: and a blocking cover. The limiting part is arranged at one end of the end cover, which is close to the box body, and is positioned in the mounting hole; an oil seal nearest to the box body along the rotation axis direction is positioned between the limiting part and the positioning piece; the baffle cover is fixedly arranged at one end of the end cover, which is far away from the box body; the main shaft passes through the end cover and the baffle cover along the direction of the rotation axis; each oil seal is positioned between the limiting part and the blocking cover.

Further, two oil seals are arranged in the mounting hole of the end cover along the direction of the rotation axis; at least one locating piece is arranged between the two oil seals.

Further, two positioning pieces are arranged between the two oil seals; the ratio of the minimum distance between the limiting part and the locating part closest to the limiting part in the direction of the rotation axis to the length of the oil seal between the locating part and the limiting part in the direction of the rotation axis is 1 to 1.2; the ratio of the minimum distance between the stopper cover and the positioning member closest to the stopper cover in the rotation axis direction to the length of the oil seal between the positioning member and the stopper cover in the rotation axis direction is in the range of 1 to 1.2.

Further, the positioning piece and the limiting part are arranged at intervals with the main shaft in the radial direction of the main shaft.

Further, fixedly arranged on the main shaft is: a bushing. The bushing is sleeved on the main shaft and positioned in the mounting hole; the oil jacket is arranged on the bushing.

The beneficial effects of this application lie in: a transmission device for a construction machine is provided which reduces the possibility of leakage of lubricating oil by reducing axial play of an oil seal.

More specifically, some embodiments of the present application may have the following specific benefits:

according to the transmission device for the engineering machinery, the oil seal is arranged between the limiting part and the locating piece, the oil seal is axially located by the limiting part and the locating piece, and further axial movement of the oil seal is limited, so that the problem that the oil seal and the main shaft are worn due to axial movement of the oil seal when the main shaft rotates at a high speed is solved, and the possibility of failure of the oil seal is reduced.

The axial deformation of the oil seal is not completely prevented by limiting, the abrasion of the oil seal caused by axial movement is reduced, the oil seal is ensured to have enough heat expansion and cold contraction space when the main shaft rotates at high speed, the loss of the oil seal is further reduced, and the sealing performance of a transmission device for engineering machinery is ensured.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, are included to provide a further understanding of the application and to provide a further understanding of the application with regard to the other features, objects and advantages of the application. The drawings of the illustrative embodiments of the present application and their descriptions are for the purpose of illustrating the present application and are not to be construed as unduly limiting the present application.

In addition, the same or similar reference numerals denote the same or similar elements throughout the drawings. It should be understood that the figures are schematic and that elements and components are not necessarily drawn to scale.

In the drawings:

FIG. 1 is a cross-sectional view of a transmission for a work machine according to one embodiment of the present application;

FIG. 2 is an enlarged view of a portion of FIG. 1 at A;

fig. 3 is a partial enlarged view at B in fig. 1.

Meaning of the reference numerals in the drawings:

100. a transmission device for construction machinery;

110. a main shaft;

120. a transmission member;

130. a case; 131. an installation space; 132. perforating;

140. an end cap; 141. a mounting hole; 142. a limit part; 143. an oiling channel;

150. an oil seal; 151. an oil storage chamber;

160. a positioning piece;

170. a grease nipple; 171. a plug;

180. a blocking cover;

190. a bushing;

a1, a rotation axis.

Detailed Description

Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While certain embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It should be understood that the drawings and embodiments of the present disclosure are for illustration purposes only and are not intended to limit the scope of the present disclosure.

It should be noted that, for convenience of description, only the portions relevant to the present application are shown in the drawings. Embodiments of the present disclosure and features of embodiments may be combined with each other without conflict.

It should be noted that references to "one", "a plurality" and "a plurality" in this disclosure are intended to be illustrative rather than limiting, and those of ordinary skill in the art will appreciate that "one or more" is intended to be understood as "one or more" unless the context clearly indicates otherwise.

The present disclosure will be described in detail below with reference to the accompanying drawings in conjunction with embodiments.

Referring to fig. 1 to 3, a transmission 100 for a construction machine according to some embodiments of the present application includes: spindle 110, driving medium 120, case 130, end cap 140, oil seal 150, and positioning member 160.

The transmission member 120 is configured to be connected to a power source for rotation about a rotation axis a1 under the driving of the power source. The transmission member 120 is coaxially and fixedly arranged on the main shaft 110 to drive the main shaft 110 to rotate when rotating. The driving member 120 may be a gear, a pulley, a sprocket, etc., and the power source may be correspondingly connected to the driving member 120 by means of a gear transmission, a belt transmission, a chain transmission, etc., so as to implement rotation of the driving member 120 and thereby drive the spindle 110 to rotate about the rotation axis a 1.

The case 130 is formed with an installation space 131 in which the driving member 120 is placed and a penetration hole 132 penetrating the installation space 131 in the direction of the rotation axis a 1. The spindle 110 passes through the through hole 132 to form a rotational connection with the casing 130 about the rotational axis a 1. The end cap 140 is fixedly disposed at one end of the case 130 in the direction of the rotation axis a 1. The end cap 140 is provided therein with a mounting hole 141 communicating with the mounting space 131. One end of the main shaft 110 passes through the through hole 132 in the direction of the rotation axis a1 and is inserted into the mounting hole 141 so that the main shaft 110 is rotatably coupled to the cap 140 about the rotation axis a 1. Thereby mounting the main shaft 110 between the case 130 and the end cap 140. The installation space 131 is filled with lubricating oil or grease for lubricating the main shaft 110, the transmission member 120, and other parts in the housing 130.

To achieve sealing of the installation space 131, at least one oil seal 150 is fixedly installed in the installation hole 141 of the end cap 140. The oil seal 150 is rotatably connected to the main shaft 110 about the rotation axis a 1. An oil seal 150 is located between the main shaft 110 and the end cap 140. The oil seal 150 contacts the end cap 140 to form the inner wall of the mounting hole 141 to isolate the main shaft 110 from the end cap 140 and to close the mounting space 131, preventing the lubricant in the mounting space 131 from leaking out of the mounting hole 141.

To achieve axial positioning of each oil seal 150, a positioning member 160 is fixedly provided on the end cap 140. Specifically, the positioning member 160 is fixedly mounted in the mounting hole 141 of the end cap 140. Meanwhile, a stopper 142 is provided at one end of the end cap 140 in the direction of the rotation axis a 1. The limiting portion 142 is located in the through hole 132. And defines at least one oil seal 150 located between the limiting portion 142 and one positioning member 160 along the rotation axis a 1.

In this way, the oil seal 150 is disposed between the limiting portion 142 and the positioning member 160, and the two are used to axially position the oil seal 150, so as to limit the axial movement of the oil seal 150, thereby reducing the problem of abrasion between the oil seal 150 and the main shaft 110 caused by the axial movement of the oil seal 150 when the main shaft 110 rotates at a high speed, and reducing the possibility of failure of the oil seal 150.

In the related art, in order to ensure the sealing performance of the transmission device 100, in a further scheme, at least two oil seals 150 are disposed in the mounting hole 141 of the end cover 140 along the direction of the rotation axis a1, so as to enhance the sealing performance in the mounting space 131 by disposing multiple oil seals 150. Meanwhile, at least one positioning member 160 is provided between two adjacent oil seals 150 in the mounting hole 141. To ensure that each oil seal 150 is restrained from axial movement by the retainer 160.

Specifically, the positioning members 160 are in one-to-one correspondence with the oil seals 150. For example, when the number of oil seals 150 is two, three, four, the number of corresponding retainers 160 is two, three, four, and so on. Meanwhile, each oil seal 150 and each positioning member 160 are sequentially arranged in the direction of the rotation axis a1, that is, one positioning member 160 is arranged between two adjacent oil seals 150, and one oil seal 150 is arranged between two adjacent positioning members 160. So as to restrict movement of each oil seal 150 in the direction of the rotation axis a1 by each positioning member 160.

Specifically, the positioning member 160 and the limiting portion 142 are disposed at intervals from the main shaft 110 in the radial direction of the main shaft 110, so as to avoid abrasion of the main shaft 110 caused by the contact of the positioning member 160 with the main shaft 110.

As an alternative embodiment, referring to fig. 2, the limiting portion 142 is disposed at an end of the end cover 140 remote from the case 130 and is disposed in the mounting hole 141. An oil seal 150 farthest from the case 130 in the direction of the rotation axis a1 is located between the stopper 142 and a positioning member 160 adjacent to the oil seal 150. At this time, the remaining oil seals 150 are located between two adjacent positioning members 160, so that the axial positioning of each oil seal 150 is realized. In this embodiment, the oil seals 150 may be replaced by removing the end caps 140 from the housing 130 one by one, and this embodiment may be suitable for the assembly when one end of the main shaft 110 is completely located in the mounting hole 141, and at this time, the end of the end cap 140 away from the housing 130 may be closed, so that the oil seal 150 furthest from the housing 130 is not damaged due to no contact with the outside, and may be replaced together with the rest of the oil seals 150.

In the related art, the oil seal 150 often has an oil reservoir 151 into which lubricating oil can enter, and the oil reservoir 151 is provided with an opening at one end in the direction of the rotation axis a1 so that lubricating oil can enter. On the basis of the above optional specific embodiment, it may be further defined that the open end of the oil storage chamber 151 of one oil seal 150 farthest from the case 130 is disposed away from the case 130, and an oil injection passage 143 is disposed on the end cover 140, so that one end of the oil injection passage 143 is communicated to the outside of the end cover 140, and the other end is communicated to the oil storage chamber 151 of one oil seal 150 farthest from the case 130 through the mounting hole 141, so that lubrication and cooling effects can be achieved by the oil injection passage 143 into the oil storage chamber 151 of the one oil seal 150, such as lubrication oil, when the spindle 110 rotates.

Specifically, the end cap 140 is fixedly provided with a grease nipple 170 by means of plugging or screwing, and one end of the grease nipple 170 is inserted into the grease filling channel 143 to close the grease filling channel 143, so that grease can be replenished into the grease storage cavity 151 when the grease nipple 170 is taken out. The grease nipple 170 is commercially available, and is a component commonly used in the field for filling grease, and the structure of the grease nipple is not improved in the present application, so the structure and principle thereof will not be described herein.

In general, the grease may be injected into the installation space 131, but when the grease nipple 170 is used as a switch for switching the grease filling passage 142 to and from the external environment, the grease filling passage can only be used for injecting grease into the installation space 131, but cannot be used for injecting grease due to the limitation of the structure of the grease nipple 170 itself.

More specifically, more openings communicating with the external environment may be additionally provided in the oil filling channel 142, and the plug 171 may be detachably mounted at the openings. When the plug 171 is fixedly mounted to the opening of the oil filling passage 142, the opening is blocked to prevent grease from leaking from the opening. In contrast, when grease is injected, the plug 171 is detached from the opening of the oil injection passage 142, so that the injection amount of grease can be observed at the opening.

In a further scheme, the end cover 140 may be separately provided, that is, the portion of the end cover 140 provided with the limiting portion 142 is fixedly connected to the portion of the end cover 140 provided with the oil seal 150 by adopting a threaded connection manner, so that when the oil seal 150 is replaced, the portion of the end cover 140 including the limiting portion 142 is detached, and the oil seal 150 farthest from the box 130 is detached first, and then the remaining oil seals 150 are detached one by one. In this way, the oil seals 150 other than the oil seal 150 closest to the case 130 can be easily replaced without draining the lubricating oil in the installation space 131 before replacing the oil seal 150.

When the transmission device 100 for engineering machinery is used, since the main shaft 110 is usually in a high-speed rotation state (for example, the rotational speed of the main shaft 110 is 800r/min or more), the oil seal 150 contacting the main shaft 110 generates heat by friction with the main shaft 110, and if the oil seal 150 cannot move completely due to the cooperation of the limiting portion 142 and the positioning member 160, the oil seal 150 cannot expand with heat and contract with cold normally, and the pressure between the main shaft 110 and the main shaft 110 increases in the radial direction of the main shaft 110, which may result in the abrasion of the oil seal 150 or the main shaft 110 being increased. However, if the limiting portion 142 and the positioning member 160 are insufficient in axially limiting the oil seal 150, the space of the oil seal 150 that is movable in the direction of the rotation axis a1 is too large, so that the axial movement of the oil seal 150 is aggravated, and the abrasion of the oil seal 150 is also serious.

Therefore, on the basis of the above alternative embodiments, it is further defined that the ratio of the minimum distance of the adjacent two positioning members 160 in the direction of the rotation axis a1 to the length of the oil seal 150 located between the adjacent two positioning members 160 in the direction of the rotation axis a1 has a value ranging from 1 to 1.2. Namely, the offset of the oil seal 150 in the direction of the rotation axis a1 is limited, on one hand, the axial movement of the oil seal 150 is limited, and meanwhile, a space is reserved for thermal expansion and contraction of the oil seal 150, so that the oil seal 150 has a deformable margin in the direction of the rotation axis a1, and abrasion generated after heating is reduced.

As an alternative embodiment, referring to fig. 3, the limiting portion 142 is disposed at an end of the end cover 140 near the case 130 and is disposed in the mounting hole 141. An oil seal 150 closest to the housing 130 in the direction of the rotation axis a1 is located between the limiting portion 142 and a positioning member 160. In this case, the transmission 100 for a construction machine further includes: a flap 180. Wherein, the blocking cover 180 is fixedly arranged at one end of the end cover 140 away from the case 130. The spindle 110 passes through the end cap 140 and the cap 180 in the direction of the rotation axis a 1. Each oil seal 150 is located between the limiting portion 142 and the blocking cover 180. That is, the retainer 160, the cover 180 and the limiting portion 142 together limit the oil seal 150. In this embodiment, the oil seal 150 closest to the stop cover 180 is removed by removing the stop cover 180, and then the remaining oil seals 150 are removed one by one to replace the oil seal 150, so that the method is more suitable for the situation when the main shaft 110 passes through the end cover 140 and the stop cover 180 to connect parts such as a drill rod, etc. so as to output torque. Since the oil seal 150 closest to the barrier cover 180 is most likely to contact foreign matters such as dust from the outside, the oil seal 150 is most easily damaged, and with this embodiment, the oil seal 150 can be more conveniently replaced.

The number of the alternative embodiment oil seals 150 is most preferably two for the production cost. Specifically, two oil seals 150 are provided in the mounting hole 141 of the end cap 140 in the direction of the rotation axis a 1. At least one positioning member 160 is disposed between the two oil seals 150.

More specifically, two positioning members 160 are provided between the two oil seals 150. In this case, similar to the above alternative embodiment, the oil injection passage 143 is provided on the end cap 140, and one end of the oil injection passage 143, which communicates with the mounting hole 141, is located between the two oil seals 150, so as to lubricate the oil seals 150.

For the same purpose as in the above alternative embodiment, in order to ensure that the oil seal 150 has a deformable space in the direction of the rotational axis a1, the alternative embodiment further defines a value of a ratio of a minimum distance between the rotational axis a1 direction limiting portion 142 and the positioning member 160 closest to the limiting portion 142 to a length of the oil seal 150 between the positioning member 160 and the limiting portion 142 in the rotational axis a1 direction in a range of 1 to 1.2. And the ratio of the minimum distance between the cap 180 and the retainer 160 closest to the cap 180 in the direction of the rotation axis a1 to the length of the oil seal 150 between the retainer 160 and the cap 180 in the direction of the rotation axis a1 is in the range of 1 to 1.2. To ensure the sealing performance of the oil seal 150.

The oil seal 150 can be replaced frequently as a consumable, but after the main shaft 110 is damaged due to friction with the oil seal 150 during operation, maintenance is relatively more time-consuming and labor-consuming. To solve this problem, in a specific embodiment, the spindle 110 may be fixedly provided with: bushing 190. Wherein, the bushing 190 is sleeved on the main shaft 110 and is positioned in the mounting hole 141. The oil seal 150 is sleeved on the bushing 190. Even if the bushing 190 is used to replace the main shaft 110 to be worn, maintenance after the bushing 190 is damaged is relatively easy, or the bushing can be directly replaced, so that the sealing performance of the transmission device 100 for engineering machinery after long-term use is further ensured.

The engineering machinery is used for illustrating the inventive concept and the technical scheme. It should be understood that the transmission device provided in the present application can be applied to equipment such as a construction machine, a mining machine, and the like, for example, a rock drill rig, and thus the "construction machine" should not be construed as limiting the technical field of application of the inventive concept.

The foregoing description is only of the preferred embodiments of the present disclosure and description of the principles of the technology being employed. It will be appreciated by those skilled in the art that the scope of the utility model in the embodiments of the present disclosure is not limited to the specific combination of the above technical features, but encompasses other technical features formed by any combination of the above technical features or their equivalents without departing from the spirit of the utility model. Such as the above-described features, are mutually substituted with (but not limited to) the features having similar functions disclosed in the embodiments of the present disclosure.

Claims (10)

1. A transmission for a construction machine, comprising: the device comprises a main shaft, a transmission piece, a box body and an end cover;

wherein the transmission piece is used for being connected to a power source to rotate around a rotation axis under the drive of the power source; the transmission part is coaxially and fixedly arranged on the main shaft so as to drive the main shaft to rotate when rotating;

the box body is provided with an installation space for placing the transmission part and a perforation penetrating through the installation space along the direction of the rotation axis; the main shaft passes through the perforation to form rotary connection with the box body around the rotary axis; the end cover is fixedly arranged at one end of the box body along the direction of the rotation axis;

the method is characterized in that:

a mounting hole communicated with the mounting space is formed in the end cover; one end of the main shaft penetrates through the through hole along the direction of the rotation axis and is inserted into the mounting hole so that the main shaft is rotationally connected to the end cover around the rotation axis;

the transmission device for the engineering machinery further comprises: the oil seal and the positioning piece;

wherein, at least one oil seal is fixedly arranged in the mounting hole of the end cover; the oil seal and the main shaft are in rotary connection around the rotary axis; the oil seal is positioned between the main shaft and the end cover to isolate the main shaft from the end cover and seal the installation space; the positioning piece is fixedly arranged in the mounting hole of the end cover;

one end of the end cover along the direction of the rotation axis is provided with a limit part; the limiting part is positioned in the perforation; at least one oil seal is positioned between the limiting part and one positioning piece along the direction of the rotation axis.

2. A transmission for a construction machine according to claim 1, wherein:

at least two oil seals are arranged in the mounting hole of the end cover along the direction of the rotation axis; at least one locating piece is arranged between two adjacent oil seals in the mounting hole.

3. A transmission for a construction machine according to claim 2, wherein:

the positioning pieces are in one-to-one correspondence with the oil seals; each oil seal and each positioning member are provided in order in the rotation axis direction so as to restrict movement of each oil seal in the rotation axis direction by each positioning member.

4. A transmission for a construction machine according to claim 3, wherein:

the limiting part is arranged at one end of the end cover, which is far away from the box body, and is positioned in the mounting hole; one oil seal farthest from the box body along the rotation axis direction is located between the limiting part and one positioning piece adjacent to the oil seal.

5. A transmission for a construction machine according to claim 3, wherein:

the ratio of the minimum distance between two adjacent positioning pieces in the direction of the rotation axis to the length of the oil seal between the two adjacent positioning pieces in the direction of the rotation axis is 1 to 1.2.

6. A transmission for a construction machine according to claim 2, wherein:

the limiting part is arranged at one end of the end cover, which is close to the box body, and is positioned in the mounting hole; one oil seal closest to the box body along the rotation axis direction is positioned between the limiting part and one positioning piece;

the transmission device for the engineering machinery further comprises: a blocking cover;

the baffle cover is fixedly arranged at one end of the end cover, which is far away from the box body; the main shaft passes through the end cover and the baffle cover along the direction of the rotation axis; each oil seal is located between the limiting part and the blocking cover.

7. A transmission for a construction machine according to claim 6, wherein:

two oil seals are arranged in the mounting hole of the end cover along the direction of the rotating axis; at least one locating piece is arranged between the two oil seals.

8. A transmission for a construction machine according to claim 7, wherein:

two positioning pieces are arranged between the two oil seals; the ratio of the minimum distance between the limiting part and the locating part closest to the limiting part in the rotation axis direction to the length of the oil seal between the locating part and the limiting part in the rotation axis direction is in the range of 1 to 1.2; the ratio of the minimum distance between the stopper cover and the positioning member closest to the stopper cover in the rotation axis direction to the length of the oil seal between the positioning member and the stopper cover in the rotation axis direction is in the range of 1 to 1.2.

9. A transmission for a construction machine according to any one of claims 1 to 8, wherein:

the locating piece and the limiting part are arranged at intervals with the main shaft in the radial direction of the main shaft.

10. A transmission for a construction machine according to any one of claims 1 to 8, wherein:

the main shaft is fixedly provided with: a bushing;

wherein the bushing is sleeved on the main shaft and positioned in the mounting hole; the oil jacket is arranged on the bushing.