Internal leakage compensation type hydraulic oil cylinder for deep water

Abstract

The invention discloses an internal leakage compensation type hydraulic oil cylinder for deep water, and belongs to the technical field of hydraulic oil cylinders. The hydraulic oil cylinder comprises a piston rod, a cylinder barrel, a compensation rod and a cylinder cover. The piston rod is assembled in the cylinder barrel, seawater and oil are isolated through the sealing ring at the opening of the cylinder barrel, a rod cavity and a rodless cavity are divided through the sealing ring on the piston rod, an opening in the other end of the cylinder barrel is in threaded connection with the cylinder cover, a sealing and guiding ring is arranged in an inner hole of the cylinder cover and matched with the compensation rod, and the rod cavity and the rodless cavity correspond to an oil inlet and an oil return opening respectively. The hydraulic oil cylinder has two compensation states, the first compensation state is the compensation state when the hydraulic cylinder is used normally, namely, the compensation force is in direct proportion to the water depth, and the second compensation state is the limit compensation state, namely, the compensation rod provides support for the piston rod after making hard contact with the piston rod. The problem that the piston rod falls back due to internal leakage or external load of the oil cylinder can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic cylinders, and in particular to an internal leakage compensation type hydraulic cylinder for deep water use. Background Art

[0002] When the hydraulic cylinder is extended for a long time, the piston rod will fall back due to leakage of oil in the cylinder and oil leakage of the control valve group. Usually, we solve this problem in two ways: the first is to add an accumulator to the oil circuit, cooperate with the oil pressure sensor, and continuously replenish the oil pressure according to the oil pressure sensor to maintain the working oil pressure. The second is to set a mechanical self-locking structure on the cylinder to keep the hydraulic cylinder from falling by self-locking in place.

[0003] However, both of the above methods have certain shortcomings. First, it is necessary to add accumulators and oil pressure sensors, and the hydraulic system needs to be kept open at the same time, which not only increases costs, but also reduces system reliability. For hydraulic cylinder accumulators that are not frequently used, they can only provide limited compensation time. Second, the mechanical self-locking structure can only be set in place, and the self-locking force is limited. It is not applicable when the deep sea pressure or load is large, and the self-locking steel balls are worn and will pollute the oil circuit. Summary of the invention

[0004] In view of this, the present invention provides an internal leakage compensation type hydraulic cylinder for deep water use, which can solve the problem of piston rod falling back caused by internal leakage of the cylinder or external load.

[0005] A deepwater internal leakage compensation hydraulic cylinder, comprising a piston rod, a cylinder barrel, a compensation rod and a cylinder cover;

[0006] The piston rod is assembled in the cylinder barrel, and the seawater and oil are isolated by the sealing ring at the mouth of the cylinder barrel. The rod chamber and the rodless chamber are divided by the sealing ring on the piston rod. The other end opening of the cylinder barrel is threadedly connected to the cylinder cover. The inner hole of the cylinder cover is provided with a sealing and a guide ring, which cooperates with the compensation rod. The rod chamber and the rodless chamber have corresponding oil inlet and oil return ports respectively.

[0007] Furthermore, the outer diameter of the compensation rod needs to be greater than or equal to the piston rod diameter depending on the usage.

[0008] Furthermore, the piston rod and the compensation rod both adopt a hollow structure, thereby increasing the volume of the rodless chamber.

[0009] Furthermore, the hydraulic cylinder has two compensation states. The first compensation state is the compensation state when the hydraulic cylinder is in normal use, that is, the compensation force is proportional to the water depth. The second compensation state is the extreme compensation state, that is, the compensation rod provides support for the piston rod after hard contact with the piston rod.

[0010] Furthermore, in the second compensation state, the supporting force of the compensation rod is: the difference between the cross-sectional area of ​​the compensation rod and the cross-sectional area of ​​the piston rod multiplied by the external water pressure.

[0011] Beneficial effects:

[0012] 1. The cylinder of the present invention has a double-outlet structure, and a compensation rod is added which is opposite to the piston rod. One end of the compensation rod protrudes outside the cylinder body, and the stroke is the same as that of the piston rod. When the hydraulic cylinder stops supplying oil, once the pressure in the rodless chamber drops due to internal leakage, the compensation rod continues to be pressed in for compensation under the action of external water pressure until the flange end supports the end face of the piston rod. At this time, the compensation rod provides a certain supporting force to the piston rod, so it can effectively prevent the stroke of the hydraulic cylinder from fluctuating under the action of external pressure, load and internal leakage of oil in deep water.

[0013] 2. The hydraulic cylinder of the present invention retains the rodless cavity structure, so the loading force is not affected. Under the same external specifications, the loading force is more than twice that of the former, and has strong applicability.

[0014] 3. The present invention has two compensation states. The first compensation state is the compensation state when the hydraulic cylinder is in normal use. The compensation force is proportional to the water depth (external pressure). The second compensation state is the limit compensation state. When the hydraulic cylinder pipeline leaks or is not used for a long time (oil leakage), the compensation rod and the piston rod provide support after hard contact. When the hydraulic cylinder leaks internally, it will first enter the compensation state 1. In the case of compensation state 1, the compensation force is larger. When the water depth (external pressure) is large, the operation of the hydraulic cylinder is basically not affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of the internal leakage compensation hydraulic cylinder for deep water use of the present invention;

[0016] Figure 2 is a schematic diagram of compensation state 1;

[0017] Figure 3 This is a schematic diagram of compensation state 2.

[0018] Among them, 1-piston rod, 2-cylinder barrel, 3-compensating rod, 4-cylinder head. DETAILED DESCRIPTION

[0019] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0020] As attached Figure 1 As shown, the present invention provides an internal leakage compensation hydraulic cylinder for deep water use, comprising a piston rod 1, a cylinder barrel 2, a compensation rod 3 and a cylinder cover 4.

[0021] The left end of the inner cavity of the cylinder barrel 2 is provided with a radial boss, which cooperates with the piston rod 1 of the T-shaped structure to limit the axial position, and the right end of the inner cavity of the cylinder barrel 2 is an open structure.

[0022] The piston rod 1 is assembled in the cylinder 2, and the sealing ring at the mouth of the cylinder 2 is used to isolate the seawater and the oil. The sealing ring on the piston rod 1 divides the rod chamber and the rodless chamber. The right end opening of the cylinder 2 is threadedly connected to the cylinder cover 4. The inner hole of the cylinder cover 4 is provided with a sealing and guide ring, which cooperates with the compensation rod 3. The rod chamber and the rodless chamber have oil inlet and oil return ports respectively. Figure 2 and 3 As shown, the hydraulic cylinder has two compensation states. The first compensation state is the compensation state when the hydraulic cylinder is in normal use, that is, the compensation force is proportional to the water depth. The second compensation state is the limit compensation state, that is, the compensation rod 3 provides support for the piston rod after hard contact with the piston rod 1. In the second compensation state, the support force of the compensation rod 3 is: the difference between the cross-sectional area of ​​the compensation rod 3 and the cross-sectional area of ​​the piston rod multiplied by the external water pressure, so as to ensure that the piston rod does not fall.

[0023] The outer diameter of the compensation rod 3 needs to be greater than or equal to the diameter of the piston rod 1 according to the usage. In order to increase the volume of the rodless cavity, the piston rod 1 and the compensation rod 3 both adopt a hollow structure.

[0024] When an internal leakage occurs in the hydraulic cylinder, it will first enter compensation state one. In compensation state one, the compensation force is larger. When the water depth (external pressure) is large, the hydraulic cylinder is basically unaffected. The present invention mainly uses compensation state one for pressure compensation.

[0025] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of 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 deepwater internal leakage compensation hydraulic cylinder, characterized in that: It includes a piston rod, a cylinder barrel, a compensating rod and a cylinder cover; The piston rod is assembled in the cylinder barrel, and the seawater and oil are isolated by the sealing ring at the mouth of the cylinder barrel. The rod chamber and the rodless chamber are divided by the sealing ring on the piston rod. The other end opening of the cylinder barrel is threadedly connected to the cylinder cover. The inner hole of the cylinder cover is provided with a sealing and a guide ring, which cooperates with the compensation rod. The rod chamber and the rodless chamber have corresponding oil inlet and oil return ports respectively.

2. The deepwater internal leakage compensation hydraulic cylinder according to claim 1, characterized in that: The outer diameter of the compensation rod needs to be greater than or equal to the piston rod diameter according to usage.

3. The deepwater internal leakage compensation hydraulic cylinder according to claim 2, characterized in that: The piston rod and the compensation rod both adopt a hollow structure.

4. The deepwater internal leakage compensation hydraulic cylinder according to claim 3, characterized in that: The hydraulic cylinder has two compensation states. The first compensation state is the compensation state when the hydraulic cylinder is in normal use, that is, the compensation force is proportional to the water depth. The second compensation state is the extreme compensation state, that is, the compensation rod provides support for the piston rod after hard contact with the piston rod.

5. A deepwater internal leakage compensation hydraulic cylinder as claimed in claim 3 or 4, characterized in that: In the second compensation state, the supporting force of the compensation rod is: the difference between the cross-sectional area of ​​the compensation rod and the cross-sectional area of ​​the piston rod multiplied by the external water pressure.

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