Rotary oscillating cylinder

Abstract

The utility model discloses a rotary oscillating cylinder, relates to the technical field of hydraulic cylinders, and solves the problems of inaccurate precision and larger reciprocating error of the rotary oscillating cylinder in the prior art. The swing cylinder comprises a swing cylinder body, a ball screw is arranged in the swing cylinder body in a rotating mode, a ball screw nut is arranged outside the ball screw in a transmission mode, the ball screw nut is in sliding fit with the swing cylinder body, and the ball screw nut is fixedly connected with a piston which is in sliding sealing fit with the swing cylinder body. An oil port communicated with a gap between the piston and the end face of the swing cylinder body is formed in the swing cylinder body. By arranging the ball screw and the ball screw nut matched with the ball screw, the transmission precision can be improved, errors during reciprocating motion are reduced, meanwhile, the piston is directly connected with the ball screw nut, the ball screw nut can be pushed to move when hydraulic oil is pumped in through the oil port, and then the ball screw is directly driven to rotate. The spiral oscillating cylinder has the characteristics of high power density, high transmission efficiency and high transmission precision.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic cylinders, in particular to a rotary swing cylinder. Background Art

[0002] The spiral swing cylinder is a hydraulic actuator that converts hydraulic energy into swinging motion. As a hydraulic actuator with rotary output, the spiral swing cylinder has obvious advantages such as compact structure, small space occupation, safety and reliability, maintenance-free, high pressure, no leakage, and extremely large output torque. Its main application areas include: swinging of the working frame of aerial work platform vehicles; swing positioning of the drill arm of mining equipment; tire or track steering of agricultural equipment and road equipment; swinging of actuators such as sweepers and forklifts; flipping of garbage bins in garbage trucks, etc.

[0003] The existing spiral swing cylinder uses the reverse transmission characteristics of the spiral transmission to limit the rotation of the nut. The hydraulic oil pushes the nut to move linearly, which is converted into the rotation of the screw or shaft through the spiral mechanism, driving the load to swing within a certain range. However, the spiral mechanism in the traditional spiral swing cylinder is mostly trapezoidal thread, with low transmission efficiency and poor precision.

[0004] For example, the Chinese utility model patent with the announcement number CN209743287U discloses a servo spiral swing cylinder controlled by a high-speed switch valve. The spiral swing cylinder is provided with an integrated block; the oil inlet pipe of the spiral swing cylinder is connected to the end straight-through pipe joint of the integrated block, and the oil return port of the spiral swing cylinder is connected to the oil return pipe of the integrated block; an encoder is installed at the bottom of the spiral swing cylinder, and a high-speed switch is installed on the integrated block. The utility model also has the problems of low transmission efficiency and poor precision, especially because it needs to reciprocate when working, and the matching clearance between the lead screw and the nut leads to a large margin in the reciprocating process, resulting in low precision and large reciprocating error. Utility Model Content

[0005] In view of the deficiencies in the above-mentioned background technology, the utility model proposes a rotary swing cylinder, which solves the problems of low precision and large reciprocating error of the rotary swing cylinder in the prior art.

[0006] The technical solution of the utility model is achieved as follows: a rotary swing cylinder comprises a swing cylinder body, a ball screw is rotatably arranged in the swing cylinder body, a ball screw nut is externally transmitted for transmission, the ball screw nut is slidably matched with the swing cylinder body, and the ball screw nut is fixedly connected with a piston which is slidably sealed with the swing cylinder body, and an oil port which connects the gap between the piston and the end face of the swing cylinder body is provided on the swing cylinder body.

[0007] Preferably, the swing cylinder body includes a cylinder barrel, and the two ends of the cylinder barrel are respectively connected to a cylinder bottom and a front end cover, the ball screw is rotatably matched with the cylinder bottom and the front end cover respectively, and the end of the ball screw passes through a through hole on the front end cover.

[0008] Preferably, bearings are provided on the cylinder bottom and the front end cover, and both ends of the ball screw are rotatably matched with the cylinder bottom and the front end cover respectively through the bearings.

[0009] Preferably, the front end cover is provided with a sealing ring for cooperating with the ball screw. The outer side wall of the ball screw nut is provided with a key slot, and the inner side wall of the swing cylinder is fixed with a key, and the key is slidably matched with the key slot.

[0010] Preferably, the cylinder bottom and the front end cover are connected to the cylinder barrel by threads or welding. The two ends of the ball screw nut are fixedly connected with pistons. The inner and outer sides of the piston are respectively provided with sealing rings for sliding sealing with the cylinder barrel and the ball screw nut.

[0011] Preferably, the oil port comprises an oil port I and an oil port II respectively arranged at two ends of the cylinder side wall. The oil port I and the oil port II are respectively connected to the oil inlet and outlet of the hydraulic oil pump through pipelines.

[0012] The beneficial effects of the utility model are as follows: by providing a ball screw and a ball screw nut matched therewith, the transmission accuracy can be improved and the error during reciprocating motion can be reduced. At the same time, the piston is directly connected to the ball screw nut, which can push the ball screw nut to move when hydraulic oil is pumped into the oil port, thereby directly driving the ball screw to rotate. The spiral swing cylinder has the characteristics of high power density, high transmission efficiency and high transmission accuracy. It solves the problem of inaccurate precision and large reciprocating error of the rotary swing cylinder in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the embodiments of the present utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0014] Figure 1 This is a schematic diagram of the cross-sectional structure of the utility model;

[0015] In the figure: 1: swing cylinder body, 2: ball screw, 3: ball screw nut, 4: piston, 5: cylinder barrel, 6: cylinder bottom, 7: front end cover, 8: bearing, 9: key, 10: oil port I, 11: oil port II. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0017] like Figure 1 As shown, embodiment 1, a rotary swing cylinder, includes a swing cylinder body 1, a ball screw 2 is provided for rotation inside the swing cylinder body 1, and a ball screw nut 3 is provided for external transmission of the ball screw 2. The cooperation of the ball screw and the ball screw nut can improve the transmission accuracy and reduce the error during reciprocating motion.

[0018] The ball screw nut 3 is in sliding cooperation with the swing cylinder body 1, and the ball screw nut 3 is fixedly connected with a piston 4 which is in sliding and sealing cooperation with the swing cylinder body 1. The swing cylinder body 1 is provided with an oil port which is connected with the gap between the piston 4 and the end surface of the swing cylinder body 1, so that when hydraulic oil is pumped into the oil port, the ball screw nut can be pushed to move, and then the ball screw can be directly driven to rotate, so that the spiral swing cylinder has the characteristics of high power density, high transmission efficiency and high transmission accuracy.

[0019] In this embodiment, the swing cylinder body 1 includes a cylinder barrel 5, and the two ends of the cylinder barrel 5 are respectively connected to a cylinder bottom 6 and a front end cover 7, and the cylinder bottom 6 and the front end cover 7 can be connected to the cylinder barrel by threads or welding, and are connected by full welding in this embodiment. The ball screw 2 is respectively rotatably matched with the cylinder bottom 6 and the front end cover 7, and one end of the ball screw 2 passes through the through hole on the front end cover 7.

[0020] As a further embodiment, bearings 8 are provided on the cylinder bottom 6 and the front cover 7, and the two ends of the ball screw 2 are respectively rotatably matched with the cylinder bottom 6 and the front cover 7 through the bearings 8. A sealing ring for matching with the ball screw 2 is provided on the front cover 7. The sealing ring can form a seal between the ball screw and the front cover to prevent the internal hydraulic oil from leaking out.

[0021] In addition, in this embodiment, the oil port includes an oil port Ⅰ10 and an oil port Ⅱ11 respectively arranged at both ends of the side wall of the cylinder 5, and the oil port Ⅰ10 and the oil port Ⅱ11 can meet the oil supply and oil return in the cylinder. When this embodiment is in use, the oil port Ⅰ10 and the oil port Ⅱ11 are respectively connected to the inlet and outlet of the hydraulic oil pump through pipelines. When the hydraulic oil pump pumps oil to the oil port Ⅰ10 through the pipeline, the oil enters between the piston and the bottom of the cylinder, so that the volume of the cavity on the left side of the piston becomes larger, pushing the piston 4 and the ball screw nut 3 to move toward the front end cover, and at the same time driving the ball screw engaged with the ball screw nut to rotate, and the rotation of the screw drives the load to rotate. At the same time, the piston is used to return the oil between the piston and the front end cover to the oil tank of the hydraulic oil pump through the pipeline. When it is necessary to reversely control the rotation of the ball screw, the hydraulic oil pump pumps oil into the cylinder through the oil port Ⅱ11, pushing the piston and the ball screw nut to move in the opposite direction, and driving the ball screw to rotate in the opposite direction.

[0022] Embodiment 2, based on embodiment 1, a key slot is provided on the outer wall of the ball screw nut 3, and a key 9 is fixedly provided on the inner wall of the swing cylinder 1, and the key 9 slides with the key slot. Pistons 4 are fixedly connected to both ends of the ball screw nut 3. When the piston drives the ball screw nut to move, the ball screw nut can only slide relative to the cylinder under the cooperation of the key and the slide slot.

[0023] The piston 4 is provided with a sealing ring for sealing with the inner wall of the cylinder 5 and a sealing ring for sealing with the outer wall of the ball screw. The sealing ring is provided to form a sealing condition so that when oil is pumped into one side of the piston, the piston and the ball screw nut can be pushed to move.

[0024] Embodiment 3, based on embodiment 1, is different from embodiment 2 in that a slider is provided on the outer wall of the ball screw nut, and the slider is slidably matched with a slide rail provided on the cylinder barrel. Thus, the sliding match between the slider and the slide rail can be used to achieve sliding guidance when the piston drives the ball screw nut to move.

[0025] Embodiment 4, based on Embodiment 1, differs from Embodiments 2 and 3 in that the piston is fixedly connected to the ball screw nut, a groove for limiting the rotation of the piston is provided inside the cylinder, and a protrusion for slidingly cooperating with the groove is provided on the side wall of the piston. When the piston is pushed by the oil and slides, the protrusion and the groove cooperate to act as a sliding guide.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A rotary swing cylinder, characterized in that: The invention comprises a swing cylinder body (1), wherein a ball screw (2) is rotatably arranged inside the swing cylinder body (1), a ball screw nut (3) is externally driven by the ball screw (2), the ball screw nut (3) is slidably matched with the swing cylinder body (1), and the ball screw nut (3) is fixedly connected with a piston (4) which is slidably and sealably matched with the swing cylinder body (1), and an oil port which communicates with the gap between the piston (4) and the end surface of the swing cylinder body (1) is arranged on the swing cylinder body (1).

2. The rotary swing cylinder according to claim 1, characterized in that: The swing cylinder body (1) comprises a cylinder barrel (5), the two ends of the cylinder barrel (5) are respectively connected to a cylinder bottom (6) and a front end cover (7), the ball screw (2) is respectively rotatably matched with the cylinder bottom (6) and the front end cover (7), and the end of the ball screw (2) passes through a through hole on the front end cover (7).

3. The rotary swing cylinder according to claim 2, characterized in that: The cylinder bottom (6) and the front end cover (7) are both provided with bearings (8), and the two ends of the ball screw (2) are rotatably matched with the cylinder bottom (6) and the front end cover (7) respectively through the bearings (8).

4. The rotary swing cylinder according to claim 3, characterized in that: The front end cover (7) is provided with a sealing ring for cooperating with the ball screw (2).

5. The rotary swing cylinder according to claim 4, characterized in that: The outer wall of the ball screw nut (3) is provided with a key slot, and the inner wall of the swing cylinder body (1) is fixedly provided with a key (9), and the key (9) is slidably engaged with the key slot.

6. The rotary swing cylinder according to claim 5, characterized in that: The cylinder bottom (6) and the front end cover (7) are connected to the cylinder barrel (5) by means of threads or welding.

7. The rotary swing cylinder according to claim 6, characterized in that: Both ends of the ball screw nut (3) are fixedly connected to pistons (4).

8. The rotary swing cylinder according to claim 7, characterized in that: The piston (4) is provided with sealing rings on both the inner and outer sides thereof for slidingly sealing with the cylinder barrel (5) and the ball screw nut (3).

9. The rotary swing cylinder according to any one of claims 2 to 8, characterized in that: The oil port comprises an oil port I (10) and an oil port II (11) respectively arranged at two ends of the side wall of the cylinder barrel (5).

10. The rotary swing cylinder according to claim 9, characterized in that: The oil port I (10) and the oil port II (11) are respectively connected to the oil inlet and outlet of the hydraulic oil pump through pipelines.

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