CN211009895U - Hydraulic oil cylinder - Google Patents

Abstract

The utility model provides a hydraulic oil cylinder, which comprises a cylinder barrel, a cylinder cover, a piston and a piston rod, a sealing device is arranged between the cylinder cover and the piston rod, and the sealing device comprises: a first main seal arranged on the inner circumference of the cylinder cover ring and the second main sealing ring, the first main sealing ring and the second main sealing ring are sleeved on the piston rod; the lip of the second main sealing ring is opposite to the lip of the first main sealing ring, and the second main sealing ring The ring is located on the side of the first main sealing ring away from the cylinder; wherein, a back pressure cavity is arranged in the cylinder head, and the back pressure cavity is provided with a liquid inlet and a liquid outlet, and the liquid outlet is connected to the lip of the first main sealing ring Between the port and the lip of the second main sealing ring, the liquid inlet is used to connect with the external pressure pipeline. In the hydraulic oil cylinder, by setting a back pressure cavity in the cylinder head, the holding force of the first main seal ring and the second main seal ring on the piston rod is improved, and the pair of the first main seal ring and the second main seal ring is improved. The tightness of the hydraulic cylinder improves the service life of the hydraulic cylinder.

Description

hydraulic cylinder

technical field

The utility model relates to the technical field of hydraulic system sealing, in particular to a hydraulic oil cylinder.

Background technique

A hydraulic cylinder is a hydraulic actuator that converts hydraulic energy into mechanical energy and performs linear reciprocating motion (or swing motion). It has simple structure and reliable operation. When using it to achieve reciprocating motion, the reduction device can be omitted, and there is no transmission gap, and the movement is stable, so it is widely used in various mechanical hydraulic systems. The hydraulic cylinder is basically composed of cylinder barrel and cylinder head, piston and piston rod, sealing device, buffer device and exhaust device. Buffers and exhausts are application specific, other devices are essential.

As the most important power actuator and key component in the hydraulic transmission system, the hydraulic cylinder is widely used in the fields of construction machinery and mining machinery. In the prior art, how to improve the tightness of the joint between the piston rod and the cylinder head has always been a difficult and painful problem.

Utility model content

In order to solve at least one of the above technical problems, the purpose of the present invention is to provide a hydraulic oil cylinder.

In order to achieve the above purpose, the technical solution of the present utility model provides a hydraulic oil cylinder, which includes a cylinder barrel, a cylinder cover, a piston and a piston rod, and a sealing device is arranged between the cylinder cover and the piston rod, and the sealing device It includes: a first main sealing ring and a second main sealing ring arranged on the inner circumference of the cylinder head, the first main sealing ring and the second main sealing ring are sleeved on the piston rod; the first main sealing ring and the second main sealing ring are sleeved on the piston rod; The lip of the second main sealing ring is arranged opposite to the lip of the first main sealing ring, and the second main sealing ring is located on the side of the first main sealing ring away from the cylinder; wherein, the There is a back pressure cavity in the cylinder head, the back pressure cavity is provided with a liquid inlet and a liquid outlet, and the liquid outlet is connected to the lip of the first main seal ring and the second column seal ring. Between the lips, the liquid inlet is used to connect with an external pressurized pipeline.

In the hydraulic oil cylinder provided by the technical solution of the present invention, a back pressure cavity is arranged in the cylinder head, and after the back pressure cavity is pressurized through an external pipeline, the cylinder head can press the first main sealing ring and the second main sealing ring tightly. The force is improved, thereby improving the holding force of the first main sealing ring and the second main sealing ring to the piston rod, thereby improving the sealing performance of the first main sealing ring and the second main sealing ring to the hydraulic cylinder, effectively preventing the External pollutants enter the hydraulic cylinder, and at the same time, the risk of hydraulic oil overflowing from the cylinder barrel to the outside of the cylinder barrel is greatly reduced, and the service life of the hydraulic cylinder is improved.

Specifically, the hydraulic oil cylinder provided by the present invention includes a cylinder barrel, a cylinder cover, a piston and a piston rod, a sealing device is arranged between the cylinder cover and the piston rod, and the sealing device includes a first main The sealing ring and the second main sealing ring, the lips of the first main sealing ring and the second main sealing ring are arranged opposite to each other, the first main sealing ring is used to prevent the hydraulic oil from overflowing from the cylinder barrel to the outside of the cylinder barrel, and the second main sealing ring It is used to prevent water or pollutants outside the cylinder from entering the cylinder. By setting a back pressure cavity in the cylinder head, the back pressure cavity is provided with a liquid inlet and a liquid outlet, and the liquid outlet is connected to the first main sealing ring. Between the lip and the lip of the second main seal ring, the liquid inlet is connected to the external pressurized pipeline, and after the back pressure chamber is pressurized through the external pressurized pipeline, the cylinder head can pressurize the first main seal ring and the second main seal ring. The pressing force of the second main sealing ring is increased, thereby improving the holding force of the first main sealing ring and the second main sealing ring on the piston rod, thereby improving the hydraulic oil cylinder of the first main sealing ring and the second main sealing ring. The sealing performance effectively prevents external pollutants from entering the hydraulic cylinder, and at the same time greatly reduces the risk of hydraulic oil overflowing from the cylinder barrel to the outside of the cylinder barrel, improving the service life of the hydraulic cylinder.

In addition, the hydraulic oil cylinder in the above-mentioned technical solution provided by the present utility model may also have the following additional technical features:

In the above technical solution, a pressure reducing valve is provided at the liquid inlet.

By arranging a pressure reducing valve at the liquid inlet, the pressure reducing valve can be automatically opened when the pressure of the liquid inlet reaches the preset pressure to discharge part of the liquid in the back pressure chamber. The preferred discharged liquid is an oil-water mixture. The second main sealing ring mainly prevents water from entering the cylinder from the outside of the cylinder, so the friction with the piston rod is large, the oil-water mixture can form an oil film on the piston rod, and the oil film can reduce the relationship between the second main sealing ring and the piston rod. The friction between the two main sealing rings plays a lubricating role, which effectively prevents the second main sealing ring from melting due to the high temperature caused by the large friction force when the second main sealing ring and the piston rod are slidingly matched, thereby improving the use of the second main sealing ring. life.

In the above technical solution, the inner circumference of the cylinder head is provided with an annular groove along the circumferential direction, and the annular groove forms the liquid outlet of the back pressure chamber.

The inner circumference of the cylinder head is provided with an annular groove in the circumferential direction, and the annular groove forms the liquid outlet of the back pressure chamber, so that the liquid in the back pressure chamber can be discharged along the annular groove on the inner circumference of the cylinder head, which is convenient for the back pressure chamber to drain outward. .

In any of the above technical solutions, the sealing device further comprises: a first buffer sealing ring arranged on the inner circumference of the cylinder head, the first buffer sealing ring is sleeved on the piston rod and located in the first buffer sealing ring. Between a main sealing ring and the cylinder, the lip of the first buffer sealing ring faces the cylinder.

The sealing device also includes a first buffer sealing ring arranged on the inner circumference of the cylinder head. The lip of the buffer sealing ring faces the cylinder, which not only plays a sealing role, but also effectively buffers the impact of the hydraulic oil in the cylinder on the first main sealing ring, preventing the first main sealing ring from being damaged due to the impact, and improving the performance. The sealing performance is improved and the service life of the first main sealing ring is improved.

In the above technical solution, the sealing device further comprises: a second buffer sealing ring arranged on the inner circumference of the cylinder head, the second buffer sealing ring is sleeved on the piston rod and located in the first main Between the sealing ring and the first buffer sealing ring, the lip of the second buffer sealing ring and the lip of the first buffer sealing ring are arranged in the same direction.

The sealing device also includes a second buffer sealing ring arranged on the inner circumference of the cylinder head, and the second buffer sealing ring is sleeved on the piston rod and located between the first main sealing ring and the first buffer sealing ring, and is connected with the first buffer sealing ring. The lips of the buffer sealing ring are arranged in the same direction, which further improves the sealing performance of the sealing device, and at the same time further reduces the impact of the hydraulic oil in the cylinder on the first main sealing ring, and further improves the service life of the first main sealing ring.

In the above technical solution, the sealing device further comprises: a third buffer sealing ring arranged on the inner circumference of the cylinder head, the third buffer sealing ring is sleeved on the piston rod, the third buffer sealing ring The ring is located between the liquid outlet of the back pressure chamber and the second main sealing ring, and the lip of the third buffer sealing ring and the lip of the second buffer sealing ring are arranged in the same direction; wherein, The inner peripheral surface of the first buffer seal ring, the second buffer seal ring and the third buffer seal ring and the piston rod slidingly cooperate with the end close to the lip is provided with a slope, and the first buffer seal The ring, the second buffer seal ring and the third buffer seal ring are all integral buffer seal rings without a retaining ring.

The sealing device also includes a third buffer sealing ring arranged on the inner circumference of the cylinder head. The buffer sealing ring plays a role in sealing and buffering protection, preventing the high pressure of the liquid in the back pressure chamber from causing a large impact on the second main sealing ring and causing damage to the second main sealing ring, so as to improve the service life of the second main sealing ring.

In the above technical solution, the cylinder head is provided with three first accommodating grooves, and the outer parts of the first buffer sealing ring, the second buffer sealing ring and the third buffer sealing ring are respectively embedded in the three buffer sealing rings. In each of the first accommodating grooves, the inner side is slidingly matched with the piston rod.

The cylinder head is provided with three first accommodating grooves, and the outer parts of the first buffer sealing ring, the second buffer sealing ring and the third buffer sealing ring are respectively embedded in the three first accommodating grooves, and the inner side slides with the piston rod. It cooperates to play a fixed and protective role, preventing the first buffer sealing ring, the second buffer sealing ring and the third buffer sealing ring from reciprocating relative to the cylinder head, improving the prevention of the first buffer sealing ring, the second buffer sealing ring and the third buffer sealing ring. The sealing stability of the three buffer seals.

In the above technical solution, the first main seal ring, the second main seal ring, the first buffer seal ring, the second buffer seal ring and the third buffer seal ring are all Y-shaped seals lock up.

The first main sealing ring, the second main sealing ring, the first buffer sealing ring, the second buffer sealing ring and the third buffer sealing ring are all Y-shaped sealing rings. Good pressure, simple structure, easy installation and replacement, help to reduce the production cost of the product.

In the above technical solution, the cylinder head is provided with two first accommodating grooves, and the outer parts of the first main sealing ring and the second main sealing ring are respectively embedded in the two first accommodating grooves , and the inner side is slidingly matched with the piston rod.

There are two first accommodating grooves on the cylinder head. The outer parts of the first main sealing ring and the second main sealing ring are respectively embedded in the two first accommodating grooves, and the inner sides are slidingly matched with the piston rod to restrict the The first main sealing ring and the second main sealing ring slide back and forth relative to the cylinder head, thereby improving the sealing reliability of the first main sealing ring and the second main sealing ring.

In the above technical solution, the sealing device further includes: a first retaining ring abutting against the end surface of the first main sealing ring close to the cylinder, and the outer part of the first retaining ring is embedded in the first retaining ring In the accommodating groove, the inner side is slidably matched with the piston rod; and/or, the second retaining ring abuts against the end surface of the second main sealing ring away from the cylinder, and the outer part of the second retaining ring is embedded It is arranged in the other first accommodating groove, and the inner side is slidingly matched with the piston rod.

The sealing device also includes a first retaining ring abutting against the end face of the first main sealing ring close to the cylinder. The first retaining ring can not only play a certain sealing role, but also effectively prevent the first main seal ring from being squeezed out of the first accommodating groove due to large frictional resistance when sliding with the piston rod. , further improving the sealing reliability of the first main sealing ring.

The sealing device also includes a second retaining ring abutting against the end face of the second main sealing ring close to the cylinder. With the sliding fit of the piston rod, the second retaining ring can not only play a certain sealing role, but also effectively prevent the second main seal ring from being squeezed out of the second accommodating groove due to the large frictional resistance when sliding with the piston rod. occurs, further improving the sealing reliability of the second main sealing ring.

In the above technical solution, the sealing device further includes: a guide ring, the guide ring is provided with a guide channel, and the piston rod reciprocates along the axis direction of the guide channel.

The sealing device also includes a guide ring, and the guide ring is provided with a guide channel for the reciprocating motion of the piston rod, which plays a role of fixing and guiding. Stability and reliability of piston rod operation.

In the above technical solution, the sealing device further includes: a dust ring, which is arranged on the side of the second main sealing ring away from the cylinder, a third accommodating groove is provided on the cylinder cover, and the dust ring is The outer part of the piston rod is arranged in the third sealing groove, and the inner side is slidably fitted with the piston rod; and

The wire retaining ring is arranged in the third accommodating groove and abuts against the end surface of the dustproof ring away from the cylinder to fix the wire retaining ring.

The sealing device also includes a dust-proof ring arranged on the side of the second main sealing ring away from the cylinder, and the dust-proof ring is arranged in the third accommodating groove on the cylinder cover to play a dust-proof role and prevent large particles outside the cylinder or Other impurities enter into the hydraulic cylinder to improve the service life of the hydraulic cylinder.

By arranging a steel wire retaining ring in the third accommodating groove, which abuts against the end face of the dustproof ring away from the cylinder, the function of fixing the dustproof ring is achieved to prevent the dustproof ring from sliding out of the third accommodating groove when the dustproof ring is slidably fitted with respect to the piston rod. is extruded, thereby improving the installation reliability of the dust ring.

Additional aspects and advantages of the present invention will become apparent in the following section of the description, or learned by practice of the present invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments in conjunction with the accompanying drawings, wherein:

1 is a partial cross-sectional structural schematic diagram of a hydraulic cylinder according to some embodiments of the present invention;

FIG. 2 is an enlarged schematic structural diagram of part A in FIG. 1 .

Wherein, the corresponding relationship between the reference numerals and component names in Figure 1 and Figure 2 is:

1 piston rod, 201 first buffer seal, 202 second buffer seal, 203 third buffer seal, 301 first retaining ring, 302 second retaining ring, 401 first main sealing ring, 402 second main sealing ring , 5 guide rings, 6 dust rings, 7 steel wire retaining rings, 8 cylinder heads, 801 first accommodating grooves, 9 back pressure chambers.

Detailed ways

In order to be able to understand the above-mentioned objects, features and advantages of the present invention more clearly, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the embodiments of the present application and the features in the embodiments may be combined with each other in the case of no conflict.

In the following description, many specific details are set forth in order to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described here. Therefore, the protection scope of the present invention is not limited by the following Limitations of the specific embodiments disclosed.

The hydraulic cylinder according to some embodiments of the present invention will be described below with reference to FIG. 1 and FIG. 2 .

Example 1

As shown in FIG. 1, an embodiment of the present invention provides a hydraulic oil cylinder, including a cylinder barrel, a cylinder cover 8, a piston and a piston rod 1, and a sealing device is provided between the cylinder cover 8 and the piston rod 1, and the sealing device includes : the first main sealing ring 401 and the second main sealing ring 402 are arranged on the inner circumference of the cylinder head 8, the first main sealing ring 401 and the second main sealing ring 402 are sleeved on the piston rod 1; the second main sealing ring The lip of 402 is arranged opposite to the lip of the first main sealing ring 401, and the second main sealing ring 402 is located on the side of the first main sealing ring 401 away from the cylinder; wherein, the cylinder head 8 is provided with a back pressure cavity 9 , the back pressure chamber 9 is provided with a liquid inlet and a liquid outlet, the liquid outlet is connected between the lip of the first main sealing ring 401 and the lip of the second column sealing ring, and the liquid inlet is used for external pressure The pipes are connected.

In the hydraulic oil cylinder provided by the embodiment of the present invention, a back pressure chamber 9 is provided in the cylinder head 8, and after the back pressure chamber 9 is pressurized through an external pipeline, the cylinder head 8 can seal the first main sealing ring 401 and the second main seal ring 401 and the second main The pressing force of the sealing ring 402 is improved, thereby improving the holding force of the first main sealing ring 401 and the second main sealing ring 402 on the piston rod 1, thereby improving the first main sealing ring 401 and the second main sealing ring. The sealing performance of 402 to the hydraulic cylinder effectively prevents external pollutants from entering the hydraulic cylinder and greatly reduces the risk of hydraulic oil overflowing from the cylinder to the outside of the cylinder, improving the service life of the hydraulic cylinder.

Specifically, the hydraulic oil cylinder provided by the present invention includes a cylinder barrel, a cylinder cover 8, a piston and a piston rod 1, and a sealing device is provided between the cylinder cover 8 and the piston rod 1, and the sealing device includes a sealing device arranged in the cylinder head 8. The first main sealing ring 401 and the second main sealing ring 402 around the circumference, the lips of the first main sealing ring 401 and the second main sealing ring 402 are arranged opposite each other, and the first main sealing ring 401 is used to prevent the hydraulic oil from flowing from the cylinder The outside of the cylinder barrel overflows, and the second main sealing ring 402 is used to prevent water or pollutants outside the cylinder barrel from entering the cylinder barrel. By setting a back pressure chamber 9 in the cylinder head 8, the back pressure chamber 9 is provided with a liquid inlet and an outlet. The liquid port and the liquid outlet are connected between the lip of the first main sealing ring 401 and the lip of the second main sealing ring 402, and the liquid inlet is connected to the external pressure pipeline, and the back pressure is applied to the back pressure through the external pressure pipeline. After the cavity 9 is pressurized, the pressing force of the cylinder head 8 on the first main sealing ring 401 and the second main sealing ring 402 is increased, thereby improving the pressure of the first main sealing ring 401 and the second main sealing ring 402 on the piston rod. 1, thereby improving the sealing performance of the first main sealing ring 401 and the second main sealing ring 402 to the hydraulic cylinder, effectively preventing external pollutants from entering the hydraulic cylinder, and greatly reducing the hydraulic oil from the cylinder. The risk of spillage out of the cylinder barrel increases the service life of the hydraulic cylinder.

Embodiment 2 (not shown in the figure)

In addition to the features of the above embodiments, this embodiment further defines that a pressure reducing valve is provided at the liquid inlet.

By arranging a pressure reducing valve at the liquid inlet, the pressure reducing valve can be automatically opened when the pressure of the liquid inlet reaches the preset pressure to discharge part of the liquid in the back pressure chamber 9. The preferred discharged liquid is an oil-water mixture. The second main sealing ring 402 mainly prevents water from entering the cylinder from outside the cylinder, so the friction with the piston rod 1 is relatively large, the oil-water mixture can form an oil film on the piston rod 1, and the oil film can reduce the second main sealing ring The friction force between 402 and the piston rod 1 plays a lubricating role, effectively preventing the second main sealing ring 402 from melting due to the high temperature caused by the large friction force when the second main sealing ring 402 slides with the piston rod 1, and then The service life of the second main sealing ring 402 is increased.

Specifically, the inner circumference of the cylinder head 8 is provided with an annular groove along the circumferential direction, and the annular groove forms the liquid outlet of the back pressure chamber 9 .

The inner circumference of the cylinder head 8 is provided with an annular groove in the circumferential direction, and the annular groove forms the liquid outlet of the back pressure cavity 9, so that the liquid in the back pressure cavity 9 can be discharged along the annular groove on the inner circumference of the cylinder head 8, which is convenient for the back pressure cavity. 9 Drain out.

Further, the sealing device further includes: a first buffer sealing ring 201 arranged on the inner circumference of the cylinder head 8 , the first buffer sealing ring 201 is sleeved on the piston rod 1 and is located between the first main sealing ring 401 and the cylinder barrel , the lip of the first buffer sealing ring 201 faces the cylinder, as shown in FIG. 1 .

The sealing device also includes a first buffer sealing ring 201 arranged on the inner circumference of the cylinder head 8 . The lip of the first buffer sealing ring 201 faces the cylinder, and at the same time, it can effectively buffer the impact of the hydraulic oil in the cylinder on the first main sealing ring 401, preventing the first main sealing ring 401. The sealing ring 401 is damaged due to impact, which improves the sealing performance and prolongs the service life of the first main sealing ring 401 .

Further, the sealing device also includes: a second buffer sealing ring 202 arranged on the inner circumference of the cylinder head 8 , the second buffer sealing ring 202 is sleeved on the piston rod 1 and located on the first main sealing ring 401 and the first buffer sealing ring Between the rings 201, the lip of the second buffer sealing ring 202 and the lip of the first buffer sealing ring 201 are arranged in the same direction.

The sealing device also includes a second buffer sealing ring 202 arranged on the inner circumference of the cylinder head 8 , and the second buffer sealing ring 202 is sleeved on the piston rod 1 and located at the first main sealing ring 401 and the first buffer sealing ring 201 . between, and are arranged in the same direction as the lip of the first buffer sealing ring 201, which further improves the sealing performance of the sealing device, and at the same time further reduces the impact of the hydraulic oil in the cylinder on the first main sealing ring 401, which further improves the The service life of the first main sealing ring 401 .

Further, the sealing device further includes: a third buffer sealing ring 203 arranged on the inner circumference of the cylinder head 8 , the third buffer sealing ring 203 is sleeved on the piston rod 1 , and the third buffer sealing ring 203 is located in the back pressure cavity 9 . Between the liquid outlet and the second main seal ring 402, and the lip of the third buffer seal ring 203 and the lip of the second buffer seal ring 202 are arranged in the same direction; wherein, the first buffer seal ring 201, the second buffer seal The inner peripheral surface of the ring 202 and the third buffer sealing ring 203 slidingly matched with the piston rod 1 is provided with an inclined surface at the end close to the lip, and the first buffer sealing ring 201, the second buffer sealing ring 202 and the third buffer sealing ring 203 are all It is an integral buffer sealing ring without a retaining ring, as shown in Figure 1 and Figure 2.

The sealing device also includes a third buffer sealing ring 203 arranged on the inner circumference of the cylinder head 8 . Between the rings 402, the third buffer sealing ring 203 plays a sealing role and also plays a buffering and protection role to prevent the high pressure of the liquid in the back pressure chamber 9 from causing damage to the second main sealing ring 402 due to a large impact. The service life of the second main sealing ring 402 is improved.

Specifically, the cylinder head 8 is provided with three first accommodating grooves 801 , and the outer portions of the first buffer sealing ring 201 , the second buffer sealing ring 202 and the third buffer sealing ring 203 are respectively embedded in the three first accommodating grooves 801 , the inner side is slidingly fitted with the piston rod 1, as shown in Figures 1 and 2.

The cylinder head 8 is provided with three first accommodating grooves 801, and the outer parts of the first buffer sealing ring 201, the second buffer sealing ring 202 and the third buffer sealing ring 203 are respectively embedded in the three first accommodating grooves 801. , the inner side is slidingly matched with the piston rod 1 to play a fixed and protective role, preventing the first buffer sealing ring 201, the second buffer sealing ring 202 and the third buffer sealing ring 203 from reciprocating relative to the cylinder head 8, improving the prevention of the first buffer sealing ring 201, the second buffer sealing ring 202 and the third buffer sealing ring 203. The sealing stability of the buffer sealing ring 201 , the second buffer sealing ring 202 and the third buffer sealing ring 203 .

Specifically, the first main sealing ring 401 , the second main sealing ring 402 , the first buffer sealing ring 201 , the second buffer sealing ring 202 and the third buffer sealing ring 203 are all Y-shaped sealing rings.

The first main sealing ring 401, the second main sealing ring 402, the first buffer sealing ring 201, the second buffer sealing ring 202 and the third buffer sealing ring 203 are all Y-shaped sealing rings. The Y-shaped sealing ring has reliable sealing performance and friction. The resistance is small, the pressure resistance is good, the structure is simple, the installation and replacement are easy, and the production cost of the product is reduced.

Specifically, the cylinder head 8 is provided with two first accommodating grooves 801, the outer parts of the first main sealing ring 401 and the second main sealing ring 402 are respectively embedded in the two first accommodating grooves 801, and the inner side is connected to the piston Rod 1 slip fit.

Two first accommodating grooves 801 are provided on the cylinder head 8. By embedding the outer parts of the first main sealing ring 401 and the second main sealing ring 402 in the two first accommodating grooves 801 respectively, the inner side is connected to the piston rod. 1. Sliding fit to limit the reciprocating sliding of the first main sealing ring 401 and the second main sealing ring 402 relative to the cylinder head 8, thereby improving the sealing reliability of the first main sealing ring 401 and the second main sealing ring 402.

Further, the sealing device further includes: a first retaining ring 301 abutting against the end face of the first main sealing ring 401 close to the cylinder, and the outer part of the first retaining ring 301 is embedded in the first accommodating groove 801, and the inner part is connected to the piston Rod 1 is a sliding fit, as shown in Figure 1.

The sealing device also includes a first retaining ring 301 abutting against the end face of the first main sealing ring 401 close to the cylinder. In 801, the inner side is slidingly matched with the piston rod 1, and the first retaining ring 301 can not only play a certain sealing role, but also can effectively prevent the first main sealing ring 401 from sliding from the first main seal ring 401 due to the large frictional resistance when sliding with the piston rod 1. The situation of being squeezed out in the accommodating groove 801 further improves the sealing reliability of the first main sealing ring 401 .

Further, the sealing device further includes a second retaining ring 302, which abuts against the end face of the second main sealing ring 402 away from the cylinder, and the outer part of the second retaining ring 302 is embedded in another first accommodating groove 801, and the inner side is The piston rod 1 is slidably fitted, as shown in Figure 1.

The sealing device also includes a second retaining ring 302 abutting against the end face of the second main sealing ring 402 close to the cylinder. In the groove, the inner side is slidingly matched with the piston rod 1, the second retaining ring 302 can not only play a certain sealing role, but also can effectively prevent the second main sealing ring 402 from sliding from the second main sealing ring 402 due to the large frictional resistance when sliding with the piston rod 1. The situation of being squeezed out in the accommodating groove further improves the sealing reliability of the second main sealing ring 402 .

Further, the sealing device further includes: a guide ring 5, the guide ring 5 is provided with a guide channel, and the piston rod 1 reciprocates along the axis direction of the guide channel, as shown in FIG. 1 .

The sealing device also includes a guide ring 5. The guide ring 5 is provided with a guide channel for the reciprocating movement of the piston rod 1, which plays a role of fixing and guiding. The piston rod 1 has a fixed movement by sliding back and forth along the axis of the guide channel. The track ensures the stability and reliability of the operation of the piston rod 1.

Further, the sealing device also includes: a dust ring 6, which is arranged on the side of the second main sealing ring 402 away from the cylinder, the cylinder cover 8 is provided with a third accommodating groove, and the outer part of the dust ring 6 is arranged on the third accommodating groove. In the sealing groove, the inner side is slidingly matched with the piston rod 1; and the wire retaining ring 7 is arranged in the third accommodating groove and abuts against the end face of the dustproof ring 6 away from the cylinder to fix the wire retaining ring 7, as shown in Figure 1 shown.

The sealing device also includes a dust-proof ring 6 arranged on the side of the second main sealing ring 402 away from the cylinder. Large particles or other impurities enter the hydraulic cylinder to improve the service life of the hydraulic cylinder.

A wire retaining ring 7 abutting against the end face of the dust ring 6 away from the cylinder is provided in the third accommodating groove, so as to fix the dust ring 6 to prevent the dust ring 6 from sliding against the piston rod 1 during sliding fit. The third accommodating groove is extruded, thereby improving the installation reliability of the dustproof ring 6 .

To sum up, in the hydraulic cylinder provided by the present invention, a back pressure cavity is arranged in the cylinder head, and the back pressure cavity has a certain pressure after being pressurized by an external pipeline, so that the cylinder head can seal against the first main seal ring and the second main seal ring. The pressing force of the sealing ring improves the holding force of the first main sealing ring and the second main sealing ring to the piston rod, thereby improving the sealing performance of the first main sealing ring and the second main sealing ring to the hydraulic cylinder, The external pollutants are effectively prevented from entering the hydraulic cylinder, and the risk of hydraulic oil overflowing from the cylinder barrel to the outside of the cylinder barrel is greatly reduced, thereby improving the service life of the hydraulic cylinder.

In the present invention, the terms "first", "second" and "third" are only used for the purpose of description, and cannot be understood as indicating or implying relative importance; the term "multiple" refers to two or two more than one, unless otherwise expressly limited. The terms "installed", "connected", "connected", "fixed" and other terms should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be It is directly connected or indirectly connected through an intermediary. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

In the description of the present invention, it should be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "rear", etc. are based on those shown in the accompanying drawings. The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore should not be construed as a reference to the present invention. limits.

In the description of this specification, the description of the terms "one embodiment", "some embodiments", "specific embodiment", etc. means that a particular feature, structure, material or characteristic described in connection with the embodiment or example is included in the present invention novel in at least one embodiment or example. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. For those skilled in the art, the present utility model may have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (10)

1. a hydraulic oil cylinder, comprising a cylinder barrel, a cylinder cover, a piston and a piston rod, a sealing device is provided between the cylinder cover and the piston rod, it is characterized in that, the sealing device comprises: a first main seal ring and a second main seal ring arranged on the inner circumference of the cylinder head, the first main seal ring and the second main seal ring are sleeved on the piston rod; The lip of the second main sealing ring is arranged opposite to the lip of the first main sealing ring, and the second main sealing ring is located on the side of the first main sealing ring away from the cylinder; Wherein, the cylinder head is provided with a back pressure cavity, the back pressure cavity is provided with a liquid inlet and a liquid outlet, and the liquid outlet is connected to the lip of the first main sealing ring and the second Between the lips of the main sealing ring, the liquid inlet is used to connect with an external pressurized pipeline. 2. The hydraulic cylinder according to claim 1, characterized in that, The liquid inlet is provided with a pressure reducing valve. 3. The hydraulic cylinder according to claim 2, characterized in that, The inner circumference of the cylinder head is provided with an annular groove along the circumferential direction, and the annular groove forms a liquid outlet of the back pressure chamber. 4. The hydraulic cylinder according to any one of claims 1 to 3, characterized in that, further comprising: A first buffer sealing ring arranged on the inner circumference of the cylinder head, the first buffer sealing ring is sleeved on the piston rod and located between the first main sealing ring and the cylinder, the first buffer sealing ring is The lip of a buffer seal faces the cylinder. 5. The hydraulic cylinder according to claim 4, characterized in that, further comprising: a second buffer seal ring arranged on the inner circumference of the cylinder head, the second buffer seal ring is sleeved on the piston rod and located between the first main seal ring and the first buffer seal ring, The lip of the second buffer sealing ring is arranged in the same direction as the lip of the first buffer sealing ring. 6. The hydraulic cylinder according to claim 5, characterized in that, further comprising: The third buffer sealing ring is arranged on the inner circumference of the cylinder head, the third buffer sealing ring is sleeved on the piston rod, and the third buffer sealing ring is located between the liquid outlet of the back pressure chamber and the between the second main sealing rings, and the lip of the third buffer sealing ring and the lip of the second buffer sealing ring are arranged in the same direction; Wherein, one end of the inner peripheral surface of the first buffer seal ring, the second buffer seal ring and the third buffer seal ring and the piston rod slidingly matched with the lip is provided with an inclined surface, and the first buffer seal ring is provided with an inclined surface. The buffer seal ring, the second buffer seal ring and the third buffer seal ring are all integral buffer seal rings without a retaining ring. 7. The hydraulic cylinder according to claim 6, characterized in that, The cylinder head is provided with three first accommodating grooves, and the outer parts of the first buffer sealing ring, the second buffer sealing ring and the third buffer sealing ring are respectively embedded in the three first accommodating grooves. In the groove, the inner side is slidingly matched with the piston rod. 8. The hydraulic cylinder according to claim 6, characterized in that, The first main sealing ring, the second main sealing ring, the first buffer sealing ring, the second buffer sealing ring and the third buffer sealing ring are all Y-shaped sealing rings. 9. The hydraulic cylinder according to any one of claims 1 to 3, characterized in that, The cylinder head is provided with two first accommodating grooves, and the outer parts of the first main sealing ring and the second main sealing ring are respectively embedded in the two first accommodating grooves, and the inner side and the outer part are respectively embedded in the two first accommodating grooves. The piston rod is slidingly fitted. 10. The hydraulic cylinder according to claim 9, characterized in that, further comprising: A first retaining ring abuts against the end surface of the first main sealing ring close to the cylinder, and the outer part of the first retaining ring is embedded in the first accommodating groove, and the inner side slides with the piston rod cooperate; and/or A second retaining ring abuts against the end surface of the second main sealing ring away from the cylinder, and the outer part of the second retaining ring is embedded in the other first accommodating groove, and the inner side is connected to the piston Rod slip fit.

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