Loading force hydraulic loading test system for ball screw performance test

Abstract

The utility model provides a loading force hydraulic loading test system for a ball screw performance test, and belongs to the technical field of ball screw performance tests. The loading device solves the problem of power loss caused by the fact that stressed parts in an existing loading device are easy to wear. The hydraulic cylinder comprises a first hydraulic cylinder and a second hydraulic cylinder fixed relative to the first hydraulic cylinder, a first piston rod arranged in the first hydraulic cylinder is connected with a second piston rod arranged in the second hydraulic cylinder in parallel, and the first hydraulic cylinder is communicated with the second hydraulic cylinder through a flow channel. When the first piston rod and the second piston rod move synchronously, liquid in the first hydraulic cylinder / the second hydraulic cylinder flows to the second hydraulic cylinder / the first hydraulic cylinder through the flow channel, and a valve used for controlling flow is arranged in the flow channel. The hydraulic cylinder is adopted to replace a traditional loading device, stressed parts are not prone to abrasion, vibration and noise are not prone to being generated, the manufacturing cost is low, operation is convenient, the magnitude of loading force is easy to control, and stability is good.

Description

Technical Field

[0001] This utility model belongs to the field of ball screw performance testing technology, and relates to a load force hydraulic loading test system for ball screw performance testing. Background Technology

[0002] Ball screws are the most commonly used transmission components in precision machinery. They are helical transmission parts composed of a screw, nut, and balls. Their main function is to convert rotary motion into linear motion, featuring high precision, reversibility, and high efficiency. Their performance directly determines and affects the overall performance of CNC machine tools. Therefore, conducting necessary performance tests on ball screws helps to identify problems early, reduce defective product rates, minimize unnecessary downtime, and improve machine tool quality. As testing technology and conditions play an increasingly important role in modern scientific research and product manufacturing, there is a demand for convenient testing under realistic conditions. This necessitates systems capable of simulating mechanical loads in actual production or applications.

[0003] To address this, a Chinese patent discloses a high-speed testing device for axial loading of a ball screw pair [application publication number CN110657987A]. A servo motor drives the ball screw pair under test to rotate, thereby causing the second worktable and the first worktable to perform linear reciprocating motion along the rolling linear guide pair. The linear reciprocating motion of the first worktable drives the transmission ball screw pair to rotate. The rotation of the transmission ball screw pair drives the loading device to rotate through the synchronous belt. By adjusting the loading device, a resistance is applied to the rotation of the transmission ball screw pair. This resistance is converted into axial force through the nut seat first and the first worktable, applied to the second worktable, and then transmitted to the ball screw pair under test through the nut seat second, thereby achieving axial loading of the ball screw pair under test.

[0004] The aforementioned loading device has a complex structure. The load-bearing parts in the loading device are prone to wear, which can lead to power loss. It is also prone to vibration and noise. Furthermore, the design and manufacturing of the loading device have high requirements for the materials and heat treatment of the parts, resulting in high manufacturing costs.

[0005] The applied force is the acceleration driving force of the motion mechanism, and its calculation formula is: F = Fa = M * a

[0006] Fa: Acceleration driving force (N)

[0007] M: The mass of the moving parts equivalent to the lead screw and nut (kg)

[0008] a: Nut acceleration (m / s²).

[0009] As can be seen from the formula, it is difficult for the operating speed and the loading force to meet the requirements of the lead screw at the same time: the loading force is large at the start, which meets the technical requirements, but the operating speed is low; after accelerating to the operating speed, the loading force is very small again; that is, the stroke that satisfies the loading force and the operating speed in the entire operating cycle is very short, or even non-existent (only one can be guaranteed). Utility Model Content

[0010] The purpose of this invention is to address the aforementioned problems in existing technologies by proposing a hydraulic loading test system for testing the load force of ball screws with a reasonable structural design.

[0011] The objective of this utility model can be achieved through the following technical solutions:

[0012] A hydraulic loading test system for ball screw performance testing includes a first hydraulic cylinder and a second hydraulic cylinder fixed relative to the first hydraulic cylinder. A first piston rod located in the first hydraulic cylinder is connected in parallel to a second piston rod located in the second hydraulic cylinder. The first hydraulic cylinder is connected to the second hydraulic cylinder through a flow channel. When the first piston rod and the second piston rod move synchronously, the liquid located in the first hydraulic cylinder / second hydraulic cylinder flows through the flow channel to the second hydraulic cylinder / first hydraulic cylinder. A valve for controlling the flow rate is provided in the flow channel.

[0013] In use, the first piston rod / second piston rod is set parallel to the ball screw, and the first piston rod / second piston rod is connected to the nut in the ball screw pair. When the screw rotates, it drives the nut to move axially, and the nut drives the first piston rod and second piston rod to move axially. The liquid in the first hydraulic cylinder / second hydraulic cylinder applies resistance to the first piston rod / second piston rod, and this resistance is the axial force applied to the nut.

[0014] The axial force of the load used in the ball screw performance test is related to the valve opening. The smaller the valve opening, the less liquid passes through the flow channel per unit time, and the greater the axial force applied to the nut; the larger the valve opening, the more liquid passes through the flow channel per unit time, and the smaller the axial force applied to the nut.

[0015] In the above-mentioned hydraulic loading test system for ball screw performance testing, a first piston is provided in the first hydraulic cylinder, and a first sealed cavity is formed between the first piston and the first hydraulic cylinder. The first piston rod is fixed to the first piston and extends out of the first hydraulic cylinder from the end away from the first sealed cavity. A second piston is provided in the second hydraulic cylinder, and a second sealed cavity is formed between the second piston and the second hydraulic cylinder. The second piston rod is fixed to the second piston and extends out of the second hydraulic cylinder from the end away from the second sealed cavity. The first sealed cavity communicates with the second sealed cavity through the above-mentioned flow channel.

[0016] When the first piston rod extends, the second piston rod retracts, and the liquid in the second hydraulic cylinder enters the first hydraulic cylinder through the flow channel; when the first piston rod retracts, the second piston rod extends, and the liquid in the first hydraulic cylinder enters the second hydraulic cylinder through the flow channel.

[0017] In the above-mentioned hydraulic loading test system for ball screw performance testing, the first hydraulic cylinder and the second hydraulic cylinder are arranged opposite to each other, and the first piston rod and the second piston rod are coaxially fixed together.

[0018] In the above-mentioned hydraulic loading test system for ball screw performance testing, the first piston rod has a first inner hole that communicates with the first sealing cavity, and the second piston rod has a second inner hole that communicates with the second sealing cavity. The first inner hole and the second inner hole communicate with each other, and the first inner hole and the second inner hole constitute the above-mentioned flow channel.

[0019] The valve is located between the first piston rod and the second piston rod.

[0020] In the above-mentioned hydraulic loading test system for ball screw performance testing, the first hydraulic cylinder is connected to a first connecting pipe that communicates with the first sealing cavity, and the other end of the first connecting pipe communicates with the second sealing cavity. The flow channel is located inside the first connecting pipe.

[0021] The valve is installed on the first connecting pipe and is used to control the opening and closing of the first connecting pipe and the flow rate.

[0022] In the above-mentioned hydraulic loading test system for ball screw performance testing, a first piston is provided in the first hydraulic cylinder, and a first sealed cavity is formed between the first piston and the first hydraulic cylinder. The first piston rod is fixed to the first piston and extends out of the first hydraulic cylinder from the end away from the first sealed cavity. A second piston is provided in the second hydraulic cylinder, and a second sealed cavity is formed between the second piston and the second hydraulic cylinder. The second piston rod is fixed to the second piston and extends out of the second hydraulic cylinder from the end with the second sealed cavity. The first sealed cavity communicates with the second sealed cavity through the above-mentioned flow channel.

[0023] When the first piston rod extends, the second piston rod extends, and the liquid in the second hydraulic cylinder enters the first hydraulic cylinder through the flow channel; when the first piston rod retracts, the second piston rod retracts, and the liquid in the first hydraulic cylinder enters the second hydraulic cylinder through the flow channel.

[0024] In the above-mentioned hydraulic loading test system for ball screw performance testing, the first hydraulic cylinder and the second hydraulic cylinder are arranged side by side, the first piston rod and the second piston rod extend in the same direction, and the first piston rod and the second piston rod are connected by a connecting rod.

[0025] In use, the connecting rod is connected to the nut of the ball screw pair. When the screw rotates, it drives the nut to move axially, and the nut drives the connecting rod to move. The connecting rod drives the first piston rod and the second piston rod to extend and retract synchronously. The liquid in the first hydraulic cylinder / second hydraulic cylinder applies resistance to the first piston rod / second piston rod. This resistance is the axial force applied to the nut.

[0026] In the above-mentioned hydraulic loading test system for ball screw performance testing, the first hydraulic cylinder is connected to a second pipe that communicates with the first sealing cavity, and the other end of the second pipe communicates with the second sealing cavity. The flow channel is located inside the second pipe.

[0027] The valve is installed on the second connecting pipe and is used to control the opening and closing of the second connecting pipe and the flow rate.

[0028] In the above-mentioned hydraulic loading test system for ball screw performance testing, the first hydraulic cylinder and the second hydraulic cylinder are relatively fixed by a mounting plate.

[0029] Both the first and second hydraulic cylinders are fixed to the mounting plate. When the first and second hydraulic cylinders are positioned opposite each other, the mounting plate is located to the side of the first and second hydraulic cylinders. When the first and second hydraulic cylinders are positioned side by side, the mounting plate is located at the ends of the first and second hydraulic cylinders.

[0030] The loading force is formed by the combined action of the acceleration driving force of the motion mechanism and the pressure difference resistance of the hydraulic cylinder.

[0031] F = Fa + Fy

[0032] Acceleration driving force:

[0033] Fa = M * a

[0034] Fa: Acceleration driving force (N)

[0035] M: The mass of the moving parts equivalent to the lead screw and nut (kg)

[0036] a: Nut acceleration (m / s²)

[0037] Hydraulic cylinder differential pressure resistance:

[0038] Fy = A*(P1-P2)

[0039] Fy: Differential pressure resistance of the hydraulic cylinder (N)

[0040] A: Piston area of ​​hydraulic cylinder (m2)

[0041] P1: Liquid pressure inside cylinder 1 (Pa)

[0042] P2: Liquid pressure inside cylinder 2 (Pa)

[0043] The design accelerates the driving force very small, with most of the effect coming from the pressure difference resistance of the hydraulic cylinder. This allows for the simultaneous satisfaction of loading force and running speed during the experiment. The screw stroke in the experiment can guarantee that a long stroke ensures that both the loading force and running speed meet the expectations, and both of these indicators are easy to adjust and achieve.

[0044] Compared with existing technologies, this hydraulic loading test system for ball screw performance testing has the following advantages: it uses a hydraulic cylinder instead of a traditional loading device, which makes the load-bearing parts less prone to wear, vibration and noise, and has low manufacturing costs; the loading force is controlled by adjusting the opening of the flow channel through a valve, which is convenient to operate and easy to control, allowing the loading force to be applied to the nut at a constant level for a long time, resulting in good stability. Attached Figure Description

[0045] Figure 1 This is a cross-sectional view of the load loading device provided in Embodiment 1.

[0046] Figure 2 This is another cross-sectional view of the load loading device provided in Embodiment 1.

[0047] Figure 3 This is a cross-sectional view of the load loading device provided in Embodiment 2.

[0048] Figure 4 This is a cross-sectional view of the load loading device provided in Embodiment 3.

[0049] In the figure, 1. First hydraulic cylinder; 2. Second hydraulic cylinder; 3. First piston rod; 4. Second piston rod; 5. Valve; 6. First piston; 7. First sealing cavity; 8. Second piston; 9. Second sealing cavity; 10. First inner hole; 11. Second inner hole; 12. First connecting pipe; 13. Connecting rod; 14. Second connecting pipe; 15. Mounting plate; 16. Connecting column. Detailed Implementation

[0050] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0051] Example 1

[0052] like Figure 1 and Figure 2 The ball screw performance test load force hydraulic loading test system shown includes a mounting plate, a first hydraulic cylinder and a second hydraulic cylinder fixed on the mounting plate. The first hydraulic cylinder and the second hydraulic cylinder are arranged opposite to each other, and the first piston rod in the first hydraulic cylinder and the second piston rod in the second hydraulic cylinder are coaxially fixed.

[0053] like Figure 1 and Figure 2 As shown, a first piston is provided inside the first hydraulic cylinder, and a first sealed cavity is formed between the first piston and the first hydraulic cylinder. A first piston rod is fixed to the first piston and extends out of the first hydraulic cylinder from the end away from the first sealed cavity (the right end in this embodiment). A second piston is provided inside the second hydraulic cylinder, and a second sealed cavity is formed between the second piston and the second hydraulic cylinder. A second piston rod is fixed to the second piston and extends out of the second hydraulic cylinder from the end away from the second sealed cavity (the left end in this embodiment).

[0054] The first sealing cavity is connected to the second sealing cavity through a flow channel.

[0055] To achieve the connection between the first and second sealing cavities while minimizing the amount of piping required, such as... Figure 1 and Figure 2 As shown, the first piston rod has a first inner hole that communicates with the first sealing cavity, and the second piston rod has a second inner hole that communicates with the second sealing cavity. The first inner hole and the second inner hole communicate with each other and form a flow channel.

[0056] A valve is installed at the connection between the first and second piston rods. This valve is used to adjust the opening of the flow channel to control the flow rate of the liquid within the channel. The smaller the valve opening, the greater the pressure difference between the first and second sealing chambers, the less liquid passes through the flow channel per unit time, and the greater the axial force applied to the nut. Conversely, the larger the valve opening, the smaller the pressure difference between the first and second sealing chambers, the more liquid passes through the flow channel per unit time, and the smaller the axial force applied to the nut.

[0057] In this embodiment, an electronic valve is used to achieve automatic adjustment; in some other embodiments, a conventional valve may be used.

[0058] When the first piston rod extends, the second piston rod retracts, and the liquid in the second hydraulic cylinder enters the first hydraulic cylinder through the flow channel; when the first piston rod retracts, the second piston rod extends, and the liquid in the first hydraulic cylinder enters the second hydraulic cylinder through the flow channel.

[0059] In operation, the first and second piston rods are arranged parallel to the ball screw and connected to the nut in the ball screw assembly via a connecting post fixed to the valve. When the screw rotates, it drives the nut to move axially, which in turn drives the first and second piston rods to move axially. The end of the connecting post near the nut has a U-shaped retainer, the nut is located inside the U-shaped retainer, and a pressure sensor is placed between the U-shaped retainer and the nut.

[0060] When the first and second piston rods move to the left, the liquid in the first sealing cavity exerts resistance on the first piston. This resistance is transmitted to the nut through the connecting post, forming an axial force on the nut. Simultaneously, the liquid flows through the flow channel to the second sealing cavity. When the first and second piston rods move to the right, the liquid in the second sealing cavity exerts resistance on the second piston. This resistance is transmitted to the nut through the connecting post, forming an axial force on the nut. Simultaneously, the liquid flows through the flow channel to the first sealing cavity.

[0061] Example 2

[0062] The structural principle of this embodiment is basically the same as that of Embodiment 1, except that, as Figure 3 As shown, a first pipe is connected to the first hydraulic cylinder and communicates with the first sealing cavity. The other end of the first pipe is connected to the second sealing cavity. The flow channel is located inside the first pipe, and the valve is located on the first pipe.

[0063] In this embodiment, the first piston rod and the second piston rod are integrated, and a connecting column is vertically fixed to the connection point of the first piston rod and the second piston rod. The end of the connecting column near the nut has a U-shaped retainer, the nut is located within the U-shaped retainer, and a pressure sensor is disposed between the U-shaped retainer and the nut.

[0064] Example 3

[0065] like Figure 4 The ball screw performance test load force hydraulic loading test system shown includes a mounting plate, a first hydraulic cylinder and a second hydraulic cylinder fixed on the mounting plate. The first hydraulic cylinder and the second hydraulic cylinder are arranged side by side. The first piston rod in the first hydraulic cylinder and the second piston rod in the second hydraulic cylinder extend in the same direction. The first piston rod and the second piston rod are connected by a connecting rod, which is arranged perpendicular to the first piston rod.

[0066] like Figure 4 As shown, a first piston is provided inside the first hydraulic cylinder, and a first sealed cavity is formed between the first piston and the first hydraulic cylinder. A first piston rod is fixed to the first piston and extends out of the first hydraulic cylinder from the end away from the first sealed cavity (the right end in this embodiment). A second piston is provided inside the second hydraulic cylinder, and a second sealed cavity is formed between the second piston and the second hydraulic cylinder. A second piston rod is fixed to the second piston and extends out of the second hydraulic cylinder from the end with the second sealed cavity (the right end in this embodiment).

[0067] The first sealing cavity is connected to the second sealing cavity through a flow channel.

[0068] like Figure 4As shown, a second connecting pipe is connected to the first hydraulic cylinder, communicating with the first sealing cavity. The other end of the second connecting pipe is connected to the second sealing cavity. A flow channel is located inside the second connecting pipe, and a valve is installed on the second connecting pipe. This valve is used to adjust the opening of the flow channel to control the flow rate of the liquid in the flow channel. The smaller the valve opening, the less liquid passes through the flow channel per unit time, and the greater the axial force applied to the nut; the larger the valve opening, the more liquid passes through the flow channel per unit time, and the smaller the axial force applied to the nut.

[0069] When the first piston rod extends, the second piston rod extends, and the liquid in the second hydraulic cylinder enters the first hydraulic cylinder through the second connecting pipe; when the first piston rod retracts, the second piston rod retracts, and the liquid in the first hydraulic cylinder enters the second hydraulic cylinder through the second connecting pipe.

[0070] In use, the first piston rod and the second piston rod are set parallel to the ball screw and connected to the nut in the ball screw pair through a connecting rod. When the screw rotates, it drives the nut to move axially, and the nut drives the first piston rod and the second piston rod to move axially.

[0071] The connecting rod has a U-shaped retainer at the end near the nut, the nut is located inside the U-shaped retainer, and a pressure sensor is placed between the U-shaped retainer and the nut. In some other embodiments, other forms of connection structures may also be used.

[0072] When the first and second piston rods move to the left (retract), the liquid in the first sealing cavity exerts resistance on the first piston. This resistance is transmitted to the nut via the connecting rod, forming an axial force on the nut. Simultaneously, the liquid flows to the second sealing cavity through the second connecting pipe. When the first and second piston rods move to the right (extend), the liquid in the second sealing cavity exerts resistance on the second piston. This resistance is transmitted to the nut via the connecting rod, forming an axial force on the nut. Simultaneously, the liquid flows to the first sealing cavity through the second connecting pipe.

[0073] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. A hydraulic loading test system for testing the performance of ball screws, characterized in that, The system includes a first hydraulic cylinder (1) and a second hydraulic cylinder (2) fixed relative to the first hydraulic cylinder (1). A first piston rod (3) located in the first hydraulic cylinder (1) and a second piston rod (4) located in the second hydraulic cylinder (2) are connected in parallel. The first hydraulic cylinder (1) is connected to the second hydraulic cylinder (2) through a flow channel. When the first piston rod (3) and the second piston rod (4) move synchronously, the liquid located in the first hydraulic cylinder (1) / second hydraulic cylinder (2) flows through the flow channel to the second hydraulic cylinder (2) / first hydraulic cylinder (1). A valve (5) for controlling the flow rate is provided in the flow channel. The magnitude of the axial force of the load for the ball screw performance test is controlled by controlling the opening degree of the valve (5).

2. The hydraulic loading test system for testing the performance of ball screws according to claim 1, characterized in that, The first hydraulic cylinder (1) is sealed with a first piston (6), and a first sealing cavity (7) is formed between the first piston (6) and the first hydraulic cylinder (1). The first piston rod (3) is fixed to the first piston (6) and extends out of the first hydraulic cylinder (1) from the end away from the first sealing cavity (7). The second hydraulic cylinder (2) is sealed with a second piston (8), and a second sealing cavity (9) is formed between the second piston (8) and the second hydraulic cylinder (2). The second piston rod (4) is fixed to the second piston (8) and extends out of the second hydraulic cylinder (2) from the end away from the second sealing cavity (9). The first sealing cavity (7) communicates with the second sealing cavity (9) through the above-mentioned flow channel.

3. The hydraulic loading test system for testing the performance of ball screws according to claim 2, characterized in that, The first hydraulic cylinder (1) and the second hydraulic cylinder (2) are arranged opposite to each other, and the first piston rod (3) and the second piston rod (4) are coaxially fixed.

4. The hydraulic loading test system for testing the performance of ball screws according to claim 3, characterized in that, The first piston rod (3) has a first inner hole (10) that communicates with the first sealing cavity (7), and the second piston rod (4) has a second inner hole (11) that communicates with the second sealing cavity (9). The first inner hole (10) and the second inner hole (11) communicate with each other. The valve (5) is located between the first inner hole (10) and the second inner hole (11). The first inner hole (10) and the second inner hole (11) constitute the above-mentioned flow channel.

5. The hydraulic loading test system for testing the performance of ball screws according to claim 3, characterized in that, The first hydraulic cylinder (1) is connected to a first pipe (12) that communicates with the first sealing cavity (7). The other end of the first pipe (12) is connected to the second sealing cavity (9). The valve (5) is located on the first pipe (12), and the flow channel is located inside the first pipe (12).

6. The hydraulic loading test system for testing the performance of ball screws according to claim 1, characterized in that, The first hydraulic cylinder (1) is sealed with a first piston (6), and a first sealing cavity (7) is formed between the first piston (6) and the first hydraulic cylinder (1). The first piston rod (3) is fixed to the first piston (6) and extends out of the first hydraulic cylinder (1) from the end away from the first sealing cavity (7). The second hydraulic cylinder (2) is sealed with a second piston (8), and a second sealing cavity (9) is formed between the second piston (8) and the second hydraulic cylinder (2). The second piston rod (4) is fixed to the second piston (8) and extends out of the second hydraulic cylinder (2) from the end with the second sealing cavity (9). The first sealing cavity (7) communicates with the second sealing cavity (9) through the above-mentioned flow channel.

7. The hydraulic loading test system for testing the performance of ball screws according to claim 6, characterized in that, The first hydraulic cylinder (1) and the second hydraulic cylinder (2) are arranged side by side. The first piston rod (3) and the second piston rod (4) extend in the same direction. The first piston rod (3) and the second piston rod (4) are connected by a connecting rod (13).

8. The hydraulic loading test system for testing the performance of ball screws according to claim 7, characterized in that, The first hydraulic cylinder (1) is connected to a second pipe (14) that communicates with the first sealing cavity (7). The other end of the second pipe (14) communicates with the second sealing cavity (9). The valve (5) is located on the second pipe (14), and the flow channel is located inside the second pipe (14).

9. The hydraulic loading test system for testing the performance of ball screws according to claim 1, 2, or 6, characterized in that, The first hydraulic cylinder (1) and the second hydraulic cylinder (2) are fixed relative to each other by a mounting plate (15).

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