Steel ball locking fine adjustment limiting device for constant power adjustment

Abstract

The utility model discloses a steel ball locking fine-tuning limiting device for constant-power adjustment, which is free of a locking nut and comprises an eccentric pin, a connecting plate, a star-shaped sealing ring arranged between the eccentric pin and the connecting plate, a fastening screw, a steel ball unit for locking and limiting, a power control valve and a shifting block, the steel ball unit comprises small steel balls and large steel balls; the small steel ball is arranged in the eccentric pin along with the fastening screw; the star-shaped sealing ring is arranged on the right side of the small steel ball; the eccentric pin presses the large steel ball, the shifting block and the star-shaped sealing ring on the connecting plate; a locking nut is omitted, the eccentric pin is of an axial sealing structure, the star-shaped sealing ring is arranged between the eccentric pin and the connecting plate, and sealing reliability is guaranteed. Force is transmitted to the large steel ball and the small steel ball for locking and limiting through the fastening screw, and when the fastening screw is locked, the small steel ball is pressed by the fastening screw, so that the large steel ball is tightly attached to the connecting plate for limiting. The device has the advantages of being good in operability, good in maintainability and high in reliability.

Description

Technical Field

[0001] The utility model relates to the technical field of hydraulic systems, in particular to a steel ball locking fine-tuning limit device for constant power regulation. Background Art

[0002] Axial piston variable displacement pump is a commonly used hydraulic component in hydraulic transmission systems. It has the characteristics of compact structure, high power density, flexible control method and fast response. Therefore, it is widely used in hydraulic control systems such as marine machinery, agricultural machinery, aerospace, etc.

[0003] In general, the power curve and power starting point of the constant power variable pump need to be adjusted before leaving the factory. This is mainly done by adjusting the eccentric screw of the power control valve to adjust the constant power starting point, adjusting the eccentric pin to select the optimal power line, and ensuring that the output power W = P 出 Q 出 It is basically a constant value.

[0004] The common constant power optimal curve adjustment is a combination of an eccentric screw and a sealing nut. When performing the optimal adjustment of the power curve of a variable pump, the operator needs to loosen the locking nut, and then use a hexagonal wrench to adjust the in and out of the eccentric screw. By adjusting the eccentric screw, the optimal power curve of the variable pump is found, and finally the locking nut is locked;

[0005] The entire adjustment process is rather cumbersome, and after the variable pump power curve has been adjusted multiple times, the threads of the eccentric screw and the connecting plate are easily damaged due to multiple relative sliding, which in turn causes the seal to fail and leads to oil leakage in the variable pump.

[0006] The common adjustment method of the eccentric screw and the locking nut is that the eccentric screw is mostly adjusted by threading to move forward or backward. Since the eccentric pin and the adjusting screw are integrated, the screw moves axially when the eccentric screw is adjusted. Especially when the length of the eccentric screw is unknown, high-pressure oil will be sprayed after the eccentric screw is emptied, causing a safety hazard.

[0007] Therefore, it is of great significance to design a constant power steel ball locking fine-tuning limit device with good operability, good maintainability, small space occupation and high reliability. Utility Model Content

[0008] The purpose of the utility model is to provide a steel ball locking fine adjustment limit device for constant power regulation. The utility model has the advantages of good operability, good maintainability and high reliability.

[0009] The technical solution of the utility model is as follows: a steel ball locking fine-tuning limit device for constant power regulation, without a locking nut, comprising an eccentric pin, a connecting plate, a star-shaped sealing ring arranged between the eccentric pin and the connecting plate, a fastening screw, a steel ball unit for locking and limiting, a power control valve and a shifting block; the steel ball unit comprises a small steel ball and a large steel ball; the small steel ball is installed in the eccentric pin, and the star-shaped sealing ring is arranged on the right side of the small steel ball; the eccentric pin presses the large steel ball, the shifting block and the star-shaped sealing ring onto the connecting plate; the small steel ball is installed in the eccentric pin along with the fastening screw.

[0010] In the aforementioned steel ball locking fine-tuning limit device for constant power adjustment, the tail end of the eccentric pin is provided with a fine-tuning slot and a fastening slot; the fine-tuning slot is used for constant power fine-tuning, and the fastening slot is used for position fixing of the fastening screw.

[0011] In the aforementioned steel ball locking fine-tuning limit device for constant power regulation, a limit pin is provided on the connecting plate, and the limit pin limits the eccentric pin axially.

[0012] In the aforementioned steel ball locking fine-tuning limit device for constant power regulation, the eccentric pin is provided with an eccentric distance e.

[0013] Compared with the prior art, the utility model eliminates the locking nut, and the eccentric pin adopts an axial sealing structure. A star-shaped sealing ring is arranged between the eccentric pin and the connecting plate to ensure the reliability of the seal; the force is transmitted to the large steel ball and the small steel ball through the fastening screw for locking and limiting. When the fastening screw is locked, the fastening screw presses the small steel ball, so that the large steel ball is close to the connecting plate for limiting;

[0014] When it is necessary to fine-tune the constant power, loosen the fastening screws to implement stepless fine-tuning;

[0015] In order to ensure the axial transmission of the eccentric pin when adjusting the fastening screw, a limit pin is added to the connecting plate so that the eccentric pin can only rotate radially;

[0016] By adopting the present application, the original adjustment process is changed from loosening the locking nut-eccentric screw-locking nut to loosening the fastening screw-adjusting the eccentric pin-fastening screw. This not only solves the difficulty in finding the point of the threaded eccentric screw and the safety hazard caused by the eccentric screw being empty, but also avoids the leakage problem caused by the overly complicated adjustment process and sealing failure after multiple adjustments. It has the advantages of good operability, good maintainability and high reliability.

[0017] Therefore, the utility model has the advantages of good operability, good maintainability and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the structure of the utility model;

[0019] Figure 2yes Figure 1 Schematic diagram of the structure in the middle WW direction;

[0020] Figure 3 This is a structural diagram of the eccentric pin of the utility model;

[0021] Figure 4 It is a power variation curve diagram of different initial contact positions of the fine-tuning eccentric pin in the embodiment of the utility model;

[0022] Figure 5 It is a curve diagram of the power offset variation at different contact positions of the fine-tuning eccentric pin in the embodiment of the utility model.

[0023] Markings in the accompanying drawings: 1-fastening screw, 2-small steel ball, 3-large steel ball, 4-star sealing ring, 5-power control valve, 6-eccentric pin, 7-connecting plate, 8-limit pin, W-shift block, K1-fine-tuning slot, K2-fastening slot, M-variable plunger, N-variable piston. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the present invention.

[0025] Embodiment. A steel ball locking fine-tuning limit device for constant power regulation, such as Figure 1 and 2 As shown, there is no locking nut, including an eccentric pin 6, a connecting plate 7, a star-shaped sealing ring 4 arranged between the eccentric pin 6 and the connecting plate 7, a fastening screw 1, a steel ball unit for locking and limiting, a power control valve 5 and a shift block W; the steel ball unit includes a small steel ball 2 and a large steel ball 3; the small steel ball 2 is installed in the eccentric pin 6, and the star-shaped sealing ring 4 is arranged on the right side of the small steel ball 2; the eccentric pin 6 presses the large steel ball 3, the shift block W and the star-shaped sealing ring 4 onto the connecting plate 7; the small steel ball 2 is installed in the eccentric pin 6 along with the fastening screw 1.

[0026] Due to the size difference between the large steel ball 3 and the small steel ball 2, the assembly order of the large steel ball 3 and the small steel ball 2 is also different. The large steel ball 3 can only be installed into the eccentric pin 6 (side by side) and inserted into the connecting plate. The small steel ball 2 is installed after the fastening and adjusting screw 1. The function of the small steel ball 2 is mainly to receive the force transmitted by the fastening and adjusting screw 1 and transmit it to the large steel ball 3. The force received by the large steel ball 3 from the small steel ball 2 can be divided into axial force and radial force. The radial force makes the two large steel balls 3 close to the connecting plate 7 to achieve locking, which can meet the fine-tuning operation required in the curve graph and find the optimal power curve.

[0027] The tail end of the eccentric pin 6 is correspondingly provided with a fine-tuning notch K1 and a fastening notch K2; the fine-tuning notch K1 is used for constant power fine-tuning, and the fastening notch K2 is used for position fixing of the fastening screw 1.

[0028] When the fastening screw 1 is tightened, the fastening screw 1 presses the small steel ball 2, so that the small steel ball 2 is closely attached to the connecting plate 7 for limiting position;

[0029] When the power control valve 5 needs to be fine-tuned, the fastening screw 1 can be loosened to implement stepless fine-tuning.

[0030] The connecting plate 7 is provided with a limit pin 8 , which limits the eccentric pin 6 axially so that the eccentric pin 6 can only rotate radially, thereby avoiding axial transmission of the eccentric pin 6 when adjusting the fastening screw 1 .

[0031] like Figure 3 As shown, the two sections L1 and L2 of the eccentric pin 6 are concentric, and the eccentricity of the middle section is e. When adjusting the eccentric pin 6, since the eccentricity e is designed for the eccentric pin 6, when the eccentric pin 6 rotates, the shift block W slightly adjusts the power control valve 5 around the axis, and the optimal curve is found according to the parameter requirements.

[0032] Take the constant power plunger pump fine-tuning as an example to explain

[0033] Since the variable lever arm La of the shift block W and the swash plate angle α are not linearly related in the variable process, there is an optimal variable lever arm La for different constant power setting values, which makes the output power curve optimal in the entire variable range.

[0034] In the actual variable process of the variable pump, the displacement of the variable piston N is fixed, and the variation range of the variable force arm La is determined by the initial contact position of the variable plunger M and the shift block W. Therefore, it is assumed that the position where the axis of the fixed force arm of the shift block W and the axis of the variable plunger M are directly opposite to each other is the zero point, the direction in which the swash plate swing angle decreases is the negative direction, and the direction in which the swash plate swing angle increases is the positive direction. The fine-tuning eccentric pin 6 is taken as an example to explore the influence of the initial contact position of the variable plunger M and the shift block W on the constant power curve.

[0035] like Figure 4 As shown, the initial contact positions of the variable plunger M and the shift block W are set to 0mm, 0.5mm and 1mm respectively. When the constant power is set to 140KW and the load pressure gradually increases, the power change curves of the variable pump at different initial contact positions; Figure 4 In the figure, the calculation ends at 7s, which is the result of parameter setting. The calculation after 7s is still a straight curve. The curve in the figure is completed at 6.6s.

[0036] like Figure 5 As shown, when the initial contact position of the variable plunger M and the shift block W changes from -1mm to 1mm, the power offset ΔPg first decreases and then increases. When the initial contact position is about 0.4mm, the power offset ΔPg is the smallest and the constant power control curve is the best.

[0037] Figure 5The contact position setting is -1mm to 1mm, and the running result is the corresponding contact position directly from -1mm to 1mm. Figure 5 The process of finding the contact position corresponding to the minimum power offset ΔPg is shown.

[0038] Therefore, from Figure 4 and 5 The data curve analysis shows that the adjustment amount of the eccentric pin 6 is small, that is, the utility model is of great significance for finding the optimal curve for similar constant power fine-tuning.

Claims

1. A steel ball locking fine-tuning limit device for constant power regulation, characterized in that: The invention discloses a non-locking nut, comprising an eccentric pin (6), a connecting plate (7), a star-shaped sealing ring (4) arranged between the eccentric pin (6) and the connecting plate (7), a fastening screw (1), a steel ball unit for locking and limiting, a power control valve (5) and a shifting block (W); the steel ball unit comprises a small steel ball (2) and a large steel ball (3); the small steel ball (2) is installed in the eccentric pin (6), and the star-shaped sealing ring (4) is arranged on the right side of the small steel ball (2); the eccentric pin (6) presses the large steel ball (3), the shifting block (W) and the star-shaped sealing ring (4) onto the connecting plate (7); the small steel ball (2) is installed in the eccentric pin (6) along with the fastening screw (1).

2. A steel ball locking fine-tuning limit device for constant power regulation according to claim 1, characterized in that: The tail end of the eccentric pin (6) is correspondingly provided with a fine-tuning notch (K1) and a fastening notch (K2); the fine-tuning notch (K1) is used for constant power fine-tuning, and the fastening notch (K2) is used for fixing the position of the fastening screw (1).

3. The steel ball locking fine-tuning limit device for constant power regulation according to claim 1 is characterized in that: The connection plate (7) is provided with a limit pin (8), and the limit pin (8) limits the eccentric pin (6) in the axial direction.

4. The steel ball locking fine-tuning limit device for constant power regulation according to claim 1, characterized in that: The eccentric pin (6) is provided with an eccentric distance e.

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