阅读说明：本技术 液压缸 (Hydraulic cylinder ) 是由 任秀枝 胡小冬 朱涛 张玉玲 车少波 于 2019-10-22 设计创作，主要内容包括：本发明涉及一种液压缸,包括：缸体(1)；活塞杆(2),可由缸体(1)的第一端伸出,并具有沿其轴向延伸的中心孔；运动转化机构,包括螺杆(3)和与螺杆(3)螺纹配合的螺套,螺杆(3)的第一端可转动地安装在缸体(1)的第二端的底壁上,螺杆(3)的第二端伸入活塞杆(2)的中心孔中,螺套与活塞杆(2)连接；第一轴承(4),套设在螺杆(3)上并安装在缸体(1)第二端的底壁上的第一轴承孔(14)内；检测部件(10),用于检测螺杆(3)的转动量以获得活塞杆(2)的移动量。应用本发明的技术方案,螺杆通过轴承安装在缸体上,改善了现有技术中存在的螺杆的固定方式使得螺杆的转动阻力较大的问题。(The present invention relates to a hydraulic cylinder, including: a cylinder body (1); a piston rod (2) extendable from a first end of the cylinder (1) and having a central bore extending axially therealong; the motion conversion mechanism comprises a screw rod (3) and a threaded sleeve in threaded fit with the screw rod (3), wherein the first end of the screw rod (3) is rotatably arranged on the bottom wall of the second end of the cylinder body (1), the second end of the screw rod (3) extends into a central hole of the piston rod (2), and the threaded sleeve is connected with the piston rod (2); the first bearing (4) is sleeved on the screw (3) and is arranged in a first bearing hole (14) in the bottom wall of the second end of the cylinder body (1); and a detection component (10) for detecting the rotation amount of the screw (3) to obtain the movement amount of the piston rod (2). By applying the technical scheme of the invention, the screw is arranged on the cylinder body through the bearing, so that the problem that the rotation resistance of the screw is larger due to the fixing mode of the screw in the prior art is solved.)

1. A hydraulic cylinder, comprising:

a cylinder body (1);

a piston rod (2) extendable from a first end of the cylinder (1) and having a central bore extending axially therealong;

the motion conversion mechanism comprises a screw rod (3) and a threaded sleeve in threaded fit with the screw rod (3), wherein the first end of the screw rod (3) is rotatably arranged on the bottom wall of the second end of the cylinder body (1), the second end of the screw rod (3) extends into the central hole of the piston rod (2), and the threaded sleeve is connected with the piston rod (2);

the first bearing (4) is sleeved on the screw (3) and is arranged in a first bearing hole (14) in the bottom wall of the second end of the cylinder body (1);

a detecting member (10) for detecting a rotation amount of the screw (3) to obtain a moving amount of the piston rod (2).

2. The hydraulic cylinder according to claim 1, characterized in that the bottom wall is provided with a through hole communicating the inner cavity of the cylinder body (1) and the first bearing hole (14), the first end of the screw (3) passes through the through hole to be connected with the first bearing (4), and one end of the first bearing hole (14) adjacent to the through hole is provided with a first limit step for limiting the axial movement of the first bearing (4) along the first bearing hole (14).

3. The hydraulic cylinder according to claim 2, further comprising a first retainer ring (15), the first retainer ring (15) being provided on a side of the first bearing (4) remote from the first retaining step to limit axial movement of the first bearing (4) along the first bearing bore (14).

4. The hydraulic cylinder according to claim 3, wherein the first end of the threaded rod (3) is provided with a thread, the hydraulic cylinder further comprising a nut (5) adapted to the thread, the nut (5) being located on a side of the first collar (15) facing away from the first bearing (4) such that the first collar (15) abuts against the first bearing (4).

5. The hydraulic cylinder according to claim 3, characterized in that a groove is provided on the inner wall of the first bearing bore (14) or on the screw (3), in which groove the first collar (15) is snapped.

6. Hydraulic cylinder according to claim 1, characterised in that it further comprises a housing (11), said housing (11) being housed at the second end of the cylinder (1), said detection member (10) being housed inside said housing (11).

7. The hydraulic cylinder of claim 6, further comprising:

the rotating shaft (6) is connected with the screw rod (3);

the second bearing (12) is sleeved on the rotating shaft (6);

the bearing seat (7) is provided with a second bearing hole matched with the second bearing (12) and connected with the cylinder body (1), and the detection part (10) is arranged on one side, far away from the screw rod (3), of the bearing seat (7).

8. Hydraulic cylinder according to claim 7, wherein the second end of the cylinder body (1) is provided with a cavity in its end face, the first bearing hole (14) being provided in the bottom of the cavity, and the bearing seat (7) being provided in the cavity.

9. Hydraulic cylinder according to claim 7, characterized in that the first end of the second bearing bore is provided with a second stop step for limiting the axial movement of the second bearing (12) along the second stop step, and that the side of the second bearing (12) facing away from the second stop step is provided with a second collar (13).

10. Hydraulic cylinder according to claim 7, characterized in that it further comprises a transmission (8), said transmission (8) comprising an input connected to said rotating shaft (6) and an output connected to said detection member (10).

Technical Field

The invention relates to the field of hydraulic equipment, in particular to a hydraulic cylinder.

Background

Fig. 1 is a schematic view showing a structure of a hydraulic cylinder capable of measuring a moving position of a piston, and as shown in fig. 1, the related art hydraulic cylinder includes a piston 6, a piston rod 23, a cylinder body 4, a front end packing cover 9, a rear end packing cover 1, and a position sensing device. The front end sealing cover 9 and the rear end sealing cover 1 are both provided with a central through hole and are locked on the port of the cylinder body 4 through bolts. The piston rod 23 is provided with a central hole. The piston rod 23 is in sliding fit with the front end sealing cover 9. The position sensing device comprises a screw rod 7, a threaded sleeve 5, an angular displacement sensor (a magnetic coding angular displacement sensor is selected and comprises a marking body 17 and a sensor probe 20) and an angular displacement sensor 18, wherein the screw rod 7 is positioned in a central hole 10 of a piston rod 23, and a radial gap exists between the screw rod 7 and the central hole 10 of the piston rod 23. The rear end of the screw rod 5 is exposed out of the rear end sealing cover 1, and the rear end of the screw rod 7 is provided with a locking nut 18. The threaded sleeve 5 is fastened at the rear end of the piston rod 23, and the threaded sleeve 5 is sleeved on the screw rod 7 and is in threaded connection with the screw rod 7. The rear part of the screw 7 is provided with a thrust step 71, the thrust step 71 is abutted against the inner wall of the rear end sealing cover 1, the rear end sealing cover 1 is fixedly provided with a tensioning cover 13, and the tensioning cover 13 is sleeved on the rear part of the screw 7 and pressed on the thrust step 71, so that the screw 7 can be prevented from moving axially. The cylinder sleeve 4, the front end sealing cover 9, the rear end sealing cover 1, the piston rod 23, the screw 7 and the tensioning cover 13 are coaxial. The angular displacement sensor is arranged outside the cylinder body and is connected with the rear end of the screw rod 7. The angular displacement sensor adopts the existing magnetic coding angular displacement sensor (or a photoelectric coding angular displacement sensor and the like), the marking body 17 is fixedly connected with the rear end of the screw 7, and the sensor probe 20 is connected with the marking body 17. The signal output line of the sensor probe 20 is connected to an external measuring instrument, which is an existing measuring instrument. Reference numeral 11 is a front end connecting piece of a piston rod 23, reference numeral 19 is an external connecting piece of a rear end sealing cover 1, reference numerals 3 and 8 are respectively a liquid inlet and a liquid outlet, reference numerals 12 and 26 are sealing rings, reference numeral 15 is a labyrinth sealing piece, the labyrinth sealing piece 15 has the function of enabling a pressure head of the hydraulic cylinder to descend and then reach the sealing ring 26, the sealing ring 26 is prevented from being pressed on the screw rod 7 due to overlarge pressure of an inner cavity of the hydraulic cylinder, and therefore the phenomenon that the rotation of the screw rod 7 is subjected to large resistance is avoided, and severe abrasion of the sealing ring 26 and large deformation of the screw rod 7 due to.

1. The screw is axially fixed by directly contacting and pressing the tightening cover 13, so that the friction force is large, the rotation resistance of the screw is large and the screw is easy to wear; when the oil cylinder retracts, the threaded sleeve 5 is directly contacted with the tensioning cover 13 to serve as a stressed contact surface, and the tensioning cover 13 is easily damaged after long-time work.

2. The measuring part comprises a marking body and a sensor probe, and is directly arranged outside the cylinder body, so that the measuring part is easily influenced by the external environment and the measuring result is inaccurate; the optical coding angular displacement sensor or the magnetic coding angular displacement sensor adopted by the part has high cost and low practicability.

Disclosure of Invention

The invention aims to provide a hydraulic cylinder, which aims to solve the problem that the rotation resistance of a screw is large due to the fixing mode of the screw in the prior art.

According to an aspect of an embodiment of the present invention, there is provided a hydraulic cylinder including:

a cylinder body;

a piston rod extendable from the first end of the cylinder body and having a central bore extending axially therealong;

the motion conversion mechanism comprises a screw rod and a threaded sleeve in threaded fit with the screw rod, wherein the first end of the screw rod is rotatably arranged on the bottom wall of the second end of the cylinder body, the second end of the screw rod extends into the central hole of the piston rod, and the threaded sleeve is connected with the piston rod;

the first bearing is sleeved on the screw rod and is arranged in a first bearing hole in the bottom wall of the second end of the cylinder body;

and the detection component is used for detecting the rotation amount of the screw rod to obtain the movement amount of the piston rod.

Optionally, a through hole communicating the inner cavity of the cylinder body and the first bearing hole is formed in the bottom wall, the first end of the screw rod penetrates through the through hole to be connected with the first bearing, and a first limiting step used for limiting the axial movement of the first bearing along the first bearing hole is arranged at one end, close to the through hole, of the first bearing hole.

Optionally, the hydraulic cylinder further includes a first retainer ring, and the first retainer ring is disposed on a side of the first bearing away from the first limit step to limit axial movement of the first bearing along the first bearing hole.

Optionally, the first end of screw rod is provided with the screw thread, and the pneumatic cylinder still includes the nut with screw thread looks adaptation, and the nut is located one side of first retaining ring back to first bearing to make first retaining ring support and lean on first bearing.

Optionally, a clamping groove is formed in the inner wall of the first bearing hole or the screw, and the first retainer ring is clamped in the clamping groove.

Optionally, the hydraulic cylinder further comprises a housing, the housing cover is disposed at the second end of the cylinder body, and the detection component is disposed in the housing.

Optionally, the hydraulic cylinder further comprises:

the rotating shaft is connected with the screw rod;

the second bearing is sleeved on the rotating shaft;

and the bearing seat is provided with a second bearing hole matched with the second bearing and is connected with the cylinder body, and the detection part is arranged on one side of the bearing seat, which is far away from the screw rod.

Optionally, a concave cavity is formed in the end face of the second end of the cylinder body, the first bearing hole is formed in the bottom of the concave cavity, and the bearing seat is arranged in the concave cavity.

Optionally, a second limiting step is arranged at the first end of the second bearing hole, the second limiting step is used for limiting the second bearing to move along the axial direction of the second bearing, and a second retaining ring is arranged on one side, far away from the second limiting step, of the second bearing.

Optionally, the hydraulic cylinder further comprises a transmission comprising an input connected to the rotating shaft and an output connected to the sensing member.

By applying the technical scheme of the invention, the screw is arranged on the cylinder body through the bearing, so that the problem that the rotation resistance of the screw is larger due to the fixing mode of the screw in the prior art is solved.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 shows a schematic construction of a prior art hydraulic cylinder; and

fig. 2 shows a schematic structural view of the hydraulic cylinder of the embodiment of the present invention.

In the figure:

1. a cylinder body; 2. a piston rod; 3. a screw; 4. a first bearing; 5. a nut; 6. a rotating shaft; 7. a bearing seat; 8. a transmission; 9. a controller; 10. a detection section; 11. a housing; 12. a second bearing; 13. a second retainer ring; 14. a first bearing bore; 15. a first retainer ring; 16. and (5) sealing rings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Fig. 2 shows a schematic structural view of the hydraulic cylinder of the present embodiment. As shown in fig. 2, the hydraulic cylinder of the present embodiment includes a cylinder body 1, a piston rod 2 movably provided in the cylinder body 1, and a motion conversion mechanism. Wherein the piston rod 2 may extend from a first end of the cylinder 1, the piston rod 2 being provided with a central bore extending in its axial direction.

The motion conversion mechanism comprises a screw rod 3 and a threaded sleeve in threaded fit with the screw rod 3, the first end of the screw rod 3 is rotatably arranged on the bottom wall of the second end of the cylinder body 1, the second end of the screw rod 3 extends into the central hole of the piston rod 2, and the threaded sleeve is connected with the piston rod 3. The hydraulic cylinder also comprises a first bearing 4, wherein the first bearing 4 is sleeved on the screw rod 3 and is arranged in a first bearing hole 14 on the bottom wall of the second end of the cylinder body 1.

When the piston rod 3 moves along the axial direction of the cylinder body 1, the threaded sleeve moves along with the piston rod 3, and the piston rod 3 is driven to rotate in the rotating process of the threaded sleeve.

The hydraulic cylinder further comprises a detection part 10, and the detection part 10 is used for detecting the rotation amount of the screw 3 to obtain the movement amount of the piston rod 2. Optionally, the detecting part 10 includes one of an angle sensor and an encoder.

The bottom wall of the second end of the cylinder body 1 is provided with a through hole which is communicated with the inner cavity of the cylinder body 1 and the first bearing hole 14, the first end of the screw rod 3 passes through the through hole and is connected with the first bearing 4, and one end, adjacent to the through hole, of the first bearing hole 14 is provided with a first limiting step which is used for limiting the axial movement of the first bearing 4 along the first bearing hole 14.

The hydraulic cylinder further comprises a sealing ring 16, and the sealing ring 16 is sleeved on the screw rod 3 and is positioned in the through hole so as to seal the inner cavity of the cylinder body 1.

The hydraulic cylinder further comprises a first retainer ring 15, and the first retainer ring 15 is arranged on one side, far away from the first limiting step, of the first bearing 4 so as to limit the axial movement of the first bearing 4 along the first bearing hole 14.

The first end of the screw 3 is provided with a thread, the hydraulic cylinder further comprises a nut 5 adapted to the thread, and the nut 5 is located on a side of the first retainer ring 15 facing away from the first bearing 4, so that the first retainer ring 15 abuts against the first bearing 4.

A clamping groove is formed in the inner wall of the first bearing hole 14 or the screw rod 3, and the first check ring 15 is clamped in the clamping groove.

The hydraulic cylinder further comprises a housing 11, the housing 11 is covered at the second end of the cylinder body 1, and the detection part 10 is arranged in the housing 11.

The hydraulic cylinder further comprises a rotating shaft 6 connected with the screw rod 3, a second bearing 12 sleeved on the rotating shaft 6 and a bearing seat 7 used for bearing the second bearing 12. The detection member 10 is provided on the side of the bearing housing 7 remote from the screw 3.

One end of the rotating shaft 6 is connected with the screw rod 3, the rotating shaft 6 extends from the screw rod 3 to the side of the bearing seat 7 far away from the screw rod 3, and the detecting component 10 detects the rotation amount of the rotating shaft 6 to obtain the movement amount of the piston rod 2.

The bearing seat 7 is connected with the bottom wall of the second end of the cylinder body 1 and is provided with a second bearing hole matched with a second shaft 12. The end face of the second end of the cylinder body 1 is provided with a concave cavity, the first bearing hole 14 is arranged at the bottom of the concave cavity, and the bearing seat 7 is arranged in the concave cavity.

The first end of second bearing hole is provided with the spacing step of second, and the spacing step of second is used for restricting second bearing 12 along its axial displacement, and one side of keeping away from the spacing step of second bearing 12 is provided with second retainer 13.

The hydraulic cylinder further comprises a transmission 8, the transmission 8 comprising an input connected to the rotating shaft 6 and an output connected to the detection member 10.

In this embodiment, the first end of screw rod 3 is rotationally installed on the diapire of the second end of cylinder body 1 and the second end of screw rod 3 stretches into in the centre bore of piston rod 2, and the swivel nut is connected on piston rod 2, and when piston rod 2 removed along cylinder body 1, the swivel nut removed and drive screw rod 3 along with piston rod 2 and rotated, and pivot 6 rotated and drives reduction gear 8 along with screw rod 3 and rotate. The detecting member 10 detects the amount of rotation of the power output end of the transmission 8 to obtain the amount of movement of the piston rod 2.

The hydraulic cylinder further includes a controller 9, and the controller 9 is electrically connected to the detection member 10 and configured to calculate the amount of movement of the piston rod 2 based on the amount of rotation detected by the detection member 10.

The controller 9, the transmission 8 and the detection component 10 are all arranged in the shell 11, which is beneficial to protecting the devices from being influenced by the external environment and ensuring the accuracy of the detection result.

The screw rod 3 optionally comprises a ball screw, the ball screw assembly converts linear motion of the piston rod 2 into rotary motion by adopting a mechanical structure, and the device is simple, reliable, quick in response and accurate in length measurement.

The measuring mechanism of the hydraulic cylinder of the embodiment is mainly internally installed in the hydraulic cylinder, and has no interference problem with the outside;

the piston rod movement measuring device of the hydraulic cylinder is a wide-range length measuring device, a large-transmission-ratio speed change mechanism is integrated inside, the requirements for different measurement lengths can be met, the universality is strong, the reliability is high, the cost is low, the length measuring part is designed into an independent fully-closed module, the sealing performance is good, the environmental suitability is strong, and the installation, the replacement and the maintenance are convenient.

The present invention is not limited to the above exemplary embodiments, and any modifications, equivalent replacements, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.