Hydraulic cylinder with oil passing inside piston rod

Abstract

The invention discloses a hydraulic cylinder with oil passing inside a piston rod. The hydraulic cylinder comprises a cylinder barrel assembly, a piston rod assembly and a piston. The piston rod assembly is sleeved with the cylinder barrel assembly, the piston rod assembly and the cylinder barrel assembly can move in the axial direction, and the piston is fixed to the piston rod assembly and divides the interior of a cylinder barrel into two cavities, namely a rod cavity and a rodless cavity. And the piston rod assembly is filled with a low-density material. On the basis of the principle of an in-rod liquid passing general structure, liquid in the rod is optimized and innovated, the problem that oil in the rod is excessively increased is solved, the weight reduction potential of the in-rod liquid passing principle structure is excavated to the maximum degree, meanwhile, cost is reduced, and resource consumption is reduced.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinders, and more particularly to a hydraulic cylinder in which oil flows through the inside of the piston rod. Background Technology

[0002] Hydraulic cylinders are hydraulic end effectors that convert hydraulic energy into linear mechanical energy. Having undergone over a century of development, they are widely recognized as fundamental and mature manufacturing components in terms of function, principle, design, and manufacturing. However, with increasingly stringent requirements for lightweight and reliable hydraulic cylinders during product research and development and upgrades, this has gradually become one of the technical bottlenecks restricting product performance. To solve this problem, without changing the cylinder's structural principles, the only solutions are to continuously develop high-strength base materials and improve manufacturing precision.

[0003] The internal fluid-conducting hydraulic cylinder solves the above problems from the perspective of innovative structural principles. The so-called internal fluid-conducting design means that the large cavity of the hydraulic cylinder is connected to the internal space of the hollow piston rod. The hydraulic fluid enters the inside of the piston rod, transferring a portion of the hydraulic pressure that originally acted entirely on the piston to the piston rod head. While the output force of the hydraulic cylinder remains unchanged, the pressure on the piston rod is reduced. This allows for a direct reduction in the size of the piston rod, thus achieving weight reduction in the hydraulic cylinder.

[0004] However, in the current internal hydraulic structure, hydraulic oil enters the rod and a large amount of hydraulic oil is permanently stored inside the piston rod. The weight increase from the hydraulic oil can account for 60% of the weight reduction of the structure, resulting in a significant reduction in the overall weight reduction effect of the cylinder. At the same time, the cost increases, causing considerable waste and greatly limiting the widespread application of this structure. Summary of the Invention

[0005] Purpose of the invention: To address the shortcomings and defects of existing technologies, this invention provides a hydraulic cylinder with internal oil circulation in the piston rod. Based on the principle of a universal structure for internal oil circulation in the rod, this invention optimizes and innovates the internal fluid, solving the problem of excessive oil accumulation in the rod, maximizing the weight reduction potential of the internal oil circulation principle structure, while reducing costs and saving resource consumption.

[0006] Technical solution: The present invention provides a hydraulic cylinder with an internally circulating piston rod, characterized in that it includes a cylinder assembly, a piston rod assembly, and a piston; the piston rod assembly is sleeved inside the cylinder assembly, and the two can move axially; the piston is fixed on the piston rod assembly, dividing the inside of the cylinder into two chambers, namely a rod chamber and a rodless chamber; the piston rod assembly is filled with a low-density material.

[0007] The piston has an axially upward hole, which opens the chamber inside the piston rod assembly near the piston and connects it to the rodless chamber of the cylinder assembly.

[0008] The rod chamber is provided with a rodless chamber oil port, and the rodless chamber is provided with a rod chamber oil port.

[0009] The piston rod assembly is filled with several low-density filler blocks.

[0010] The piston is equipped with a blocking piston, which can slide axially within a limited range inside the piston's orifice.

[0011] The piston rod assembly is filled with several low-density particles.

[0012] The rod cavity is provided with a rod cavity oil port two, and the rodless cavity is provided with a rodless cavity oil port two.

[0013] When the cylinder extends, oil enters the rodless chamber through the rodless chamber port and returns oil through the rod chamber port. Pressure is built up in the rodless chamber, and the piston rod is connected to the rodless chamber. The pressure in the rodless chamber is directly conducted to the internal chamber of the piston rod. The hydraulic pressure is transmitted to the left end of the piston rod oil passage chamber, thereby reducing the load in the axial range of the piston rod.

[0014] The pressure in the rodless chamber first acts on the blocking piston, which then transmits the pressure to the oil-particle mixture inside the piston rod; the hydraulic pressure is then transmitted to the left end of the piston rod oil passage chamber, thereby reducing the load on the piston rod within the axial range.

[0015] Beneficial Effects: Compared with the prior art, the present invention has the following significant advantages: While the piston rod cavity is filled with oil, the present invention further fills it with low-density blocks / particles, ensuring pressure transmission while further reducing the weight of the rod-inserted hydraulic cylinder. This invention proposes a novel rod-inserted hydraulic cylinder, solving the problems of excessive fluid entering the piston rod, leading to unsatisfactory weight reduction and high hydraulic oil consumption, thus facilitating the widespread application of this technical principle. Attached Figure Description

[0016] Figure 1 A schematic diagram of the structure of a conventional hydraulic cylinder in existing technology. Figure 1 ;

[0017] Figure 2 A schematic diagram of the structure of a conventional rod-type hydraulic cylinder. Figure 2 ;

[0018] Figure 3 This is a schematic diagram of the structure of the present invention. Figure 1 ;

[0019] Figure 4 This is a schematic diagram of the structure of the present invention. Figure 2 ;

[0020] In the diagram, 1 is the cylinder assembly; 11 is the first oil port of the rodless chamber; 12 is the first oil port of the rod chamber; 13 is the second oil port of the rodless chamber; 14 is the second oil port of the rod chamber; 2 is the piston rod assembly; 3 is the piston; 4 is the low-density filler block; 5 is the low-density particles; and 6 is the barrier piston. Detailed Implementation

[0021] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] Option 1: As Figure 3 The specific structure of the rod-type hydraulic cylinder of the present invention consists of: a cylinder assembly 1, a piston rod assembly 2, a piston 3, and low-density filler blocks 4. The piston rod assembly 2 and the cylinder assembly 1 have the same structure and layout as conventional hydraulic cylinders, that is, the piston rod assembly 2 is sleeved inside the cylinder assembly 1, and the two can move relative to each other along the axial direction. The piston rod assembly 2 isolates the inside of the cylinder into two chambers, namely the rod chamber and the rodless chamber. The oil inlets 12 and 11 of the rod chamber and the rodless chamber are respectively opened on the cylinder assembly 1. The piston 3 has holes opened along the axial direction, so that the internal chamber of the piston rod assembly 2 is opened and connected to the rodless chamber inside the cylinder assembly 1. Several low-density filler blocks 4 are pre-installed inside the piston rod assembly 2.

[0023] Option 2: Figure 4 In another implementation of the present invention, the low-density filler block 4 in Scheme 1 is replaced with low-density particles 5. At the same time, in order to prevent them from intruding into other systems, a barrier piston 6 is installed on the piston 3. The barrier piston 6 can slide axially in a limited manner in the inner hole of the piston 3.

[0024] Working principle:

[0025] Principle of rod fluid optimization:

[0026] Both Scheme 1 and Scheme 2 involve pre-filling with lightweight materials, which occupy some space and thus significantly reduce the amount of hydraulic oil entering. All three schemes optimize the hydraulic oil flow rate.

[0027] Work status:

[0028] When the cylinder extends, oil enters the rodless chamber through the rodless chamber port 11, and oil returns to the rod chamber through the rod chamber port 12. Pressure is built up in the rodless chamber. In Scheme 1, the piston rod is connected to the rodless chamber, and the pressure in the rodless chamber is directly conducted to the internal chamber of the piston rod. In Scheme 2, the pressure in the rodless chamber first acts on the blocking piston 6, and the blocking piston 6 then transmits the pressure to the oil-particle mixture inside the piston rod. All three schemes transmit the hydraulic pressure to the right end of the piston rod, thereby reducing the load in the axial range of the piston rod.

[0029] When the cylinder retracts, oil enters the rod chamber through the rod chamber port 12 and returns to the rodless chamber through the rodless chamber port 11. Pressure is built up in the rod chamber, but the fluid inside the rod has no driving force. The fluid inside the rod will not return to the rod with the oil in the rodless chamber, and will remain in the piston rod under normal working conditions, serving as the medium for load transfer from the rodless chamber to the bottom of the piston rod.

[0030] Those skilled in the art should have a basic understanding of the hydraulic cylinder technology involved in this invention, and be able to understand that the specific implementation examples of the structural form, connection scheme, and control system proposed in this invention are simplified and variable. Any other examples obtained by adjusting, enriching, or improving the examples described in this invention without substantial innovation are within the scope of protection of this invention. Such adjustments, enrichments, and improvements include, but are not limited to, the following:

[0031] 1) For ease of intuitive understanding, the hydraulic cylinder shown in the example has been greatly simplified, including: the sealing system is not shown, the components are combined into a piston rod assembly and a cylinder assembly, and accessories such as oil pipes and fasteners are omitted. Researchers in the field should understand that enriching the above details is not a substantial innovative work.

[0032] 2) The layout of the oil port and mechanical interface in the example are adjustable. For example, the oil port can be arranged at the bottom of the piston rod, and the cylinder bottom can also be equipped with a hinge for hinged connection.

[0033] 3) Filling materials of other structural forms and materials are also within the scope of protection of this invention.

Claims

1. A hydraulic cylinder with oil circulating inside the piston rod, characterized in that: It includes a cylinder assembly (1), a piston rod assembly (2) and a piston (3); the piston rod assembly (2) is fitted inside the cylinder assembly (1) and the two can move axially; the piston (3) is fixed on the piston rod assembly (2) and the cylinder is divided into two chambers, namely the rod chamber and the rodless chamber; the piston rod assembly (2) is filled with low-density material.

2. The hydraulic cylinder with oil circulating inside the piston rod according to claim 1, characterized in that: The piston (3) has a hole in the axial direction, so that the chamber inside the piston rod assembly (2) near the piston (3) is opened and communicates with the rodless chamber of the cylinder assembly (1).

3. The hydraulic cylinder with oil circulating inside the piston rod according to claim 1, characterized in that: The rod chamber is provided with a rodless chamber oil port (11), and the rodless chamber is provided with a rod chamber oil port (12).

4. The hydraulic cylinder with oil circulating inside the piston rod according to claim 3, characterized in that: The piston rod assembly (2) is filled with several low-density filler blocks (4).

5. The hydraulic cylinder with oil circulating inside the piston rod according to claim 2, characterized in that: The piston (3) is provided with a blocking piston (6), which can slide axially in a limited manner within the hole of the piston (3).

6. The hydraulic cylinder with oil circulating inside the piston rod according to claim 5, characterized in that: The piston rod assembly (2) is filled with several low-density particles (5).

7. The hydraulic cylinder with oil circulating inside the piston rod according to claim 6, characterized in that: The rod cavity is provided with a rod cavity oil port two (14), and the rodless cavity is provided with a rodless cavity oil port two (13).

8. A hydraulic cylinder with oil circulating inside the piston rod according to any one of claims 1-4, characterized in that: When the cylinder extends, the rodless chamber receives oil through the rodless chamber oil port 1 (11), and the rod chamber returns oil through the rod chamber oil port 1 (12). Pressure is established in the rodless chamber, and the piston rod is connected to the rodless chamber. The pressure in the rodless chamber is directly conducted to the internal chamber of the piston rod. The hydraulic pressure is transmitted to the left end of the piston rod oil passage, thereby reducing the load in the axial range of the piston rod.

9. A hydraulic cylinder with oil circulating inside the piston rod according to any one of claims 5-7, characterized in that: The pressure in the rodless chamber first acts on the blocking piston (6), and the blocking piston (6) then transmits the pressure to the oil-particle mixture in the piston rod; the hydraulic pressure is transmitted to the left end of the piston rod oil passage chamber, thereby reducing the load in the axial range of the piston rod.

Images