A measuring tool and method for measuring the axial clearance of a spherical piston in a hydraulic plunger pump.

Abstract

This invention proposes a measuring tool and method for measuring the axial clearance of spherical pistons in a hydraulic plunger pump. The tool includes a base plate, a rotating assembly, an indexing and positioning assembly, a positioning assembly, a measuring mechanism, and a quick-clamping mechanism. The rotating assembly accurately positions multiple spherical piston rods on the shaft-piston assembly in the circumferential direction. The quick-clamping mechanism then fixes the shaft-piston assembly axially, ensuring that the multiple spherical piston rods are in the same measurement state. The indexing and positioning assembly measures the axial clearance of each spherical piston rod individually, resulting in high detection efficiency and accurate measurement data.

Description

Technical Field

[0001] This invention relates to the field of aviation repair technology, specifically to a measuring tool and method for measuring the axial clearance of a spherical piston in a hydraulic plunger pump. Background Technology

[0002] In the field of aircraft manufacturing and repair, variable flow hydraulic pumps are widely used; electro-hydraulic pumps are the emergency energy source for aircraft power hydraulic systems. This component is the last line of defense to ensure the safety of aircraft handling, and its reliability is directly related to flight safety.

[0003] An electro-hydraulic pump has a key component: the shaft-piston assembly; this assembly, such as... Figure 1 As shown, it has a shaft 7-1-1, nine spherical piston rods 7-1-2-1 and a fixed seat 7-1-2-3. One end of each spherical piston rod has a ball head that mates with the fixed seat, and the other end has a ball head with a diameter ΦA. The nine spherical piston rods are pressed into the fixed seat by a related process and are evenly distributed around the shaft. During operation, as the shaft rotates, each spherical piston rod can rotate flexibly within a deflection angle range of 39° in any direction, but cannot disengage. In the initial work, no design requirements were specified for the axial clearance between the spherical piston rod head and the fixed seat. The design requirements only required that the spherical piston rod could reach the set deflection angle. However, in actual application and modification research, it was found that the axial clearance affects the pressure stability and rotor life of the hydraulic pump. Therefore, dimensional requirements for the axial clearance were proposed. Moreover, it was required that the axial clearance of all nine spherical piston rods be obtained under the same measurement conditions, and that the outer surface roughness of the spherical piston rod of each spherical piston rod be Ra0.2 or higher. Damage to any surface was not allowed during the inspection. Since the nine spherical piston rods are evenly distributed around the shaft, there is currently no relevant method to obtain the axial clearance data of all nine spherical piston rods under the same measurement conditions. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention proposes a measuring tool and method for measuring the axial clearance of spherical pistons in a hydraulic plunger pump. A rotating assembly is used to accurately position the nine spherical piston rods on the shaft-piston assembly in the circumferential direction, thereby axially fixing the shaft-piston assembly under the action of a quick-clamping mechanism. This ensures that the nine spherical piston rods are in the same measurement state. An indexing and positioning assembly is used to measure the axial clearance of each of the nine spherical piston rods individually, resulting in high detection efficiency and accurate measurement data.

[0005] The technical solution of this invention is as follows:

[0006] The hydraulic plunger pump spherical piston axial clearance measuring tool includes a base plate, a rotating assembly, an indexing and positioning assembly, a positioning assembly, a measuring mechanism, and a quick clamping mechanism.

[0007] The quick clamping mechanism includes a fixed bracket and a center assembly; the fixed bracket is fixedly mounted on the base plate, and the center assembly is mounted on the fixed bracket and can move axially, cooperating with the rotating assembly to clamp the shaft-piston assembly;

[0008] The rotating assembly consists of a central shaft and a geared disc that are fastened together. The smaller diameter section engages with a positioning bracket in the positioning assembly, mounting the rotating assembly on the positioning bracket with its stepped surface flush against the bracket wall for axial positioning of the central shaft. The larger diameter section of the central shaft has a toothed end face that engages with the central tooth of the shaft-piston assembly. The shaft-piston assembly is clamped and fixed from both sides via the central shaft and the center point. The geared disc has N evenly distributed tooth grooves, where N is the number of spherical piston rods in the shaft-piston assembly. The root of each tooth groove is a circular groove with a diameter of ΦA, where ΦA is the diameter of the outer ball end of the spherical piston rod. The upper part of the tooth groove is a rectangular groove. The outer ball end of the spherical piston rod can extend into the circular groove at the root of the tooth groove and is fixed by a moving block slot inserted from the rectangular groove.

[0009] The positioning component includes a positioning bracket and a movable block. The upper part of the positioning bracket has a through hole for mounting the central shaft of the rotating component and a through hole for mounting the measuring rod. These two through holes are parallel to each other, and the distance between the central axes of the two through holes is equal to the distance between the axis of the central shaft of the rotating component and the axis of the circular groove at the root of the tooth groove of the gear plate. The upper part of the positioning bracket also has a longitudinal groove with a pin hole on the groove wall. The movable block is installed by engaging the pin hole on the groove wall with a cylindrical pin, and the movable block can rotate around the cylindrical pin.

[0010] The movable block has an L-shaped structure and an elongated hole on the main support arm. The elongated hole is installed by a cylindrical pin engaging with a pin hole on the groove wall, and the movable block can move along the cylindrical pin through the elongated hole. The thickness of the auxiliary arm is equal to the width of the rectangular groove at the top of the tooth groove. The end of the auxiliary arm has a spherical groove with a diameter of ΦA, which can engage with the outer ball head of the spherical piston rod located in the circular groove at the root of the tooth groove. When the spherical groove at the end of the auxiliary arm is in contact with the outer ball head of the spherical piston rod located in the circular groove at the root of the tooth groove, the length direction of the elongated hole is parallel to the central axis of the rotating component, thereby driving the spherical piston rod to move along the central axis of the rotating component.

[0011] The indexing and positioning assembly includes a positioning pin seat, a positioning pin, a compression spring, and a screw plug. The positioning pin seat is installed on the side wall of the positioning bracket. The positioning pin seat has a positioning stepped pin hole. The positioning pin, the compression spring, and the screw plug are installed in the positioning stepped pin hole in sequence. When the positioning pin seat is installed on the positioning bracket, the positioning pin can position the tooth groove in the gear plate, thereby positioning the rotating assembly.

[0012] The measuring mechanism includes a digital display, a measuring bracket, and a measuring rod. The measuring rod is a stepped rod, with its larger diameter section inserted into a through hole in the upper part of the positioning bracket for mounting the measuring rod, and its smaller diameter section extending axially into a circular groove at the root of the tooth groove of the gear plate. The upper part of the measuring bracket has a through hole, and the side wall of the through hole has a screw hole. The digital display is installed in the through hole of the measuring bracket by a snap ring and is fastened by a clamping screw in the screw hole. The measuring end of the digital display is coaxially pressed against the end of the measuring rod, and the measuring rod can move axially under the action of the spherical piston rod, and the displacement is displayed by the digital display.

[0013] Furthermore, the fixed bracket has an inverted T-shaped structure, with its bottom fixedly connected to the base plate. The upper part of the fixed bracket has parallel through holes, one of which is used to arrange the top component, and the other is a threaded hole used to arrange the limiting screw to prevent the top component from coming off the fixed bracket.

[0014] Furthermore, the center assembly includes a center, a movable sleeve, and a screw. The movable sleeve is installed in the through hole of the fixed bracket for arranging the center assembly and has a small clearance fit with the through hole, allowing it to move axially along the through hole. The movable sleeve has a stepped through hole at its center, the larger diameter section of which is used to fit with the center. The center fits with the larger diameter section of the stepped through hole with a small clearance, allowing it to move axially along the larger diameter section of the stepped through hole. The smaller diameter section of the stepped through hole is a threaded hole used to fit with the screw. A first compression spring 10 is provided between the screw and the center. When the screw is rotated, the first compression spring 10 pushes the center, causing the center to firmly clamp the shaft-piston assembly. An elongated hole along the axial direction is opened on the side wall of the movable sleeve, and a radial through hole is provided on the center. A pin is installed in the radial through hole of the center, and the pin fits with the elongated hole on the side wall of the movable sleeve to achieve axial positioning of the center. The two ends of the outer side of the movable sleeve have radial protrusions at different circumferential positions, which are used to fit with the fixed bracket and the limiting screw to constrain the axial movement range of the movable sleeve.

[0015] Furthermore, the positioning bracket has an inverted T-shaped structure, with its bottom fixedly connected to the base plate; the positioning bracket has three mounting holes in the middle with parallel axes but not on the same plane, for mounting the indexing positioning component.

[0016] Furthermore, the moving block is made of a soft material.

[0017] Furthermore, when the locating pin positions the rotating component, the locating pin is directly against the top of the tooth groove, and the axis of the locating pin intersects perpendicularly with the axis of the central axis of the rotating component.

[0018] Furthermore, the bottom of the fixed bracket, positioning bracket, and measuring bracket are all fixedly connected to the base plate by hexagonal bolts and positioned by cylindrical pins to ensure that the bracket positions are consistent after repeated installation.

[0019] Furthermore, the measuring mechanism also includes a compression spring and a connector; the connector has a stepped through hole, wherein the small diameter section is fitted with the large diameter section of the measuring rod with a small clearance, and the connector is fixedly connected to the measuring rod by a cylindrical pin. A third compression spring is installed between the large diameter section of the stepped through hole of the connector and the measuring bracket, and the third compression spring ensures that the measuring rod always has a preload force in contact with the spherical piston rod.

[0020] The method for measuring the axial clearance of a spherical piston in a hydraulic plunger pump using the above-mentioned device includes the following steps:

[0021] Step 1: Insert the outer ball end of the spherical piston rod on the shaft-piston assembly into the circular groove with diameter ΦA at the root of the tooth groove of the rotating assembly, so that the axis of each spherical piston rod is parallel to the axis of the central axis of the rotating assembly, and the teeth on the end face of the central axis of the rotating assembly mesh with the central teeth of the shaft-piston assembly.

[0022] Step 2: Drag the handle to the outermost position to release the quick clamping mechanism; rotate the moving block around the cylindrical pin to open it.

[0023] Step 3: Insert the central shaft of the rotating assembly assembled with the shaft-piston assembly into the through hole of the positioning bracket. After pushing the handle into place, rotate the handle to make the center press against the tapered hole of the shaft-piston assembly, thus reliably clamping the shaft-piston assembly. Rotate the moving block around the cylindrical pin so that the spherical groove with diameter ΦA of the moving block mates with the ball end of the spherical piston rod located in the groove at the root of the tooth groove. The shaft-piston assembly is now in the test state.

[0024] Step 4: Push the moving block away from the measuring mechanism to its limit position, clear the digital display, and then push the moving block towards the measuring mechanism to its limit position. At this time, the reading on the digital display is the axial clearance of the spherical piston rod.

[0025] Step 5: Rotate the moving block around the cylindrical pin to return it to the open state; pull back the measuring rod to separate it from the outer ball head of the spherical piston rod; rotate the rotating assembly to engage the synchronous positioning pin into the top of the next tooth groove of the rotating assembly; rotate the moving block around the cylindrical pin again to make the spherical groove with diameter ΦA of the moving block engage with the outer ball head of the spherical piston rod in the tooth root groove, and release the measuring rod to make it contact the outer ball head of the spherical piston rod in the tooth root groove of the currently facing tooth again. Repeat step 4 to obtain the axial clearance of the current spherical piston rod.

[0026] Step 6: Repeat step 5 to complete the axial clearance measurement of all spherical piston rods in sequence;

[0027] Step 7: Rotate the moving block around the cylindrical pin, rotate the handle to move the tip outward, remove the rotating assembly and the shaft-piston assembly, position the rotating assembly at the bottom, remove the shaft-piston assembly with the axis vertical, and complete the axial clearance measurement of the spherical piston of the entire product.

[0028] Beneficial effects

[0029] The hydraulic plunger pump axial clearance measuring tool and measurement method proposed in this invention have the following advantages:

[0030] 1. During measurement, the nine spherical piston rods (7-1-2-1) are fixed in the rotating assembly (part 7) to protect each piston head from damage and facilitate testing.

[0031] 2. The use of an indexing and positioning assembly ensures that each spherical piston rod (7-1-2-1) is in the correct measurement state, thus improving detection efficiency.

[0032] 3. The product is easy to clamp using a quick-clamping mechanism.

[0033] 4. Using a soft material moving block (part 6) to push and pull the spherical piston rod (7-1-2-1) will not damage the product.

[0034] This measuring instrument enables rapid and accurate measurement of the axial clearance of spherical pistons, solving the technical challenge of measuring this type of axial clearance using conventional methods. It features anti-human error protection, high testing efficiency, and effective control over product quality.

[0035] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0036] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0037] Figure 1 This is a schematic diagram of the part being tested.

[0038] Figure 2 This is a schematic front view of the fixture of the present invention.

[0039] Figure 3 This is a schematic top view of the fixture of the present invention.

[0040] Figure 4 This is a cross-sectional view (AA) of the fixture of the present invention.

[0041] Figure 5 This is a schematic diagram of the movable block, (a) front view, (b) side view.

[0042] Figure 6 This is a schematic diagram of the rotating component, (a) front view, (b) side view.

[0043] Figure 7 This is a schematic diagram of a fixed bracket, (a) front view, (b) side view.

[0044] Figure 8 This is a schematic diagram of the movable set, (a) front view, (b) side view.

[0045] Figure 9 This is a schematic diagram of the positioning bracket, (a) front view, (b) side view.

[0046] Figure 10 This is a schematic diagram of a locating pin seat, (a) front view, (b) side view.

[0047] Figure 11 This is a schematic diagram of the measuring rod.

[0048] Figure 12 This is a 3D diagram of the rotating component.

[0049] In the diagram: 7-1-1, shaft; 7-1-2-1, spherical piston rod; 7-1-2-3, fixed seat;

[0050] In the diagram: 1. Snap ring; 2. Clamping screw; 3. Measuring bracket; 4. Connector; 5. Measuring rod; 6. Moving block; 7. Rotating assembly; 8. Center; 9. Fixed bracket; 10. First compression spring; 11. Movable sleeve; 12. Screw; 13. Handle; 14. Limit screw; 15. Positioning bracket; 16. Base plate; 17. Plug; 18. Positioning pin seat; 19. Positioning pin; 20. Second compression spring; 21. Digital display; 22. Third compression spring; 23. First cylindrical pin; 24. Second cylindrical pin; 25. Third cylindrical pin; 26. Washer; 27. Socket head cap screw; 28. Hex bolt; 29. ​​Fourth cylindrical pin; 30. Hex bolt. Detailed Implementation

[0051] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0052] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0053] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0054] like Figure 1 As shown, the shaft-piston assembly on the electric hydraulic pump has a shaft 7-1-1, nine spherical piston rods 7-1-2-1, and a fixed seat 7-1-2-3. The nine spherical piston rods are pressed into the fixed seat using relevant processes and are evenly distributed around the shaft. During operation, as the shaft rotates, each spherical piston rod can rotate flexibly within a 39° deflection angle range in any direction but cannot disengage. Since the axial clearance affects the pressure stability and rotor life of the hydraulic pump, it is necessary to obtain the axial clearance of the nine spherical piston rods under the same measurement conditions. Therefore, this embodiment proposes a hydraulic plunger pump spherical piston axial clearance measuring tool, such as... Figure 2 As shown, it includes a base plate 16, a rotating assembly, an indexing and positioning assembly, a positioning assembly, a measuring mechanism, and a quick clamping mechanism.

[0055] The quick clamping mechanism includes a fixed bracket 9 and a top tip assembly; the fixed bracket is securely mounted on the base plate, and the top tip assembly is mounted on the fixed bracket and can move axially, cooperating with the rotating assembly to clamp the shaft-piston assembly.

[0056] like Figure 7 As shown, the fixed bracket 9 has an inverted T-shaped structure. Its bottom is fixedly connected to the base plate by hexagonal bolts 28 and positioned by a fourth cylindrical pin 29, ensuring that the fixed bracket's position and the clamped shaft-piston assembly's state are consistent after repeated installations. The upper part of the fixed bracket has parallel through holes, one for arranging the center assembly and the other a threaded hole for arranging the limiting screw 14. The limiting screw prevents the center assembly from detaching from the fixed bracket.

[0057] The center assembly includes a center 8, a movable sleeve 11, and a screw 12. For example... Figure 8 As shown, the movable sleeve is installed in the through hole of the fixed bracket for arranging the tip assembly, and has a small clearance fit with the through hole, allowing it to move axially along the through hole. The movable sleeve has a stepped through hole at its center, the large diameter section of which is used to mate with the tip. The tip and the large diameter section of the stepped through hole have a small clearance fit, allowing the tip to move axially along the large diameter section of the stepped through hole. The small diameter section of the stepped through hole is a threaded hole for mate with a screw. A first compression spring 10 is located between the screw and the tip. When the screw is rotated, the first compression spring 10 pushes the tip, causing the tip to firmly clamp the shaft-piston assembly. To constrain the position of the tip within the large diameter section of the stepped through hole, an elongated hole along the axial direction is opened on the side wall of the movable sleeve, and a radial through hole is provided on the tip. A pin is installed in the radial through hole of the tip, and the tip is axially limited by the engagement of the pin with the elongated hole on the side wall of the movable sleeve. The two ends of the outer surface of the movable sleeve have radial protrusions at different circumferential positions, which are used to mate with the fixed bracket and the limiting screw to constrain the axial movement range of the movable sleeve. The outer end of the screw is fitted with a handle 13 via an internal hex screw 27 and a washer 26.

[0058] By pushing the screw with the handle, the movable sleeve can be moved within the through hole of the fixed bracket. When the radial protrusion on the outer side of one end of the movable sleeve contacts the side of the fixed bracket, the movable sleeve is limited. Then, by rotating the screw, the first compression spring pushes the tip, so that the tip firmly clamps the shaft-piston assembly.

[0059] like Figure 2 , Figure 3 , Figure 6 and Figure 12 As shown, the rotating assembly consists of a central shaft and a geared disc that are fastened together. The central shaft is a stepped shaft, wherein the small diameter section is used to mate with the positioning bracket 15 in the positioning assembly, mounting the rotating assembly on the positioning bracket, and the stepped surface is in contact with the wall surface of the positioning bracket, for axial positioning of the central shaft; the large diameter section of the central shaft has a toothed end face, which can mate with the central tooth of the shaft-piston assembly; the shaft-piston assembly is clamped and fixed from both sides by the central shaft and the center. The geared disc has 9 toothed grooves evenly distributed on it, the root of the toothed groove is a circular groove with a diameter of ΦA, where ΦA is the diameter of the ball end of the spherical piston rod; the upper part of the toothed groove is a rectangular groove; the ball end of the spherical piston rod can extend into the circular groove at the root of the toothed groove, and is fixed by the slot of the moving block inserted from the rectangular groove.

[0060] The positioning assembly includes a positioning bracket 15 and a moving block 16. For example... Figure 2 , Figure 3 and Figure 9As shown, the positioning bracket has an inverted T-shaped structure. Its bottom is fixed to the base plate with hexagonal bolts and positioned using cylindrical pins to ensure consistent positioning after repeated installations. The positioning bracket has three parallel but not coplanar mounting holes in its center for installing the indexing positioning assembly. The upper part of the positioning bracket has through holes for installing the central shaft of the rotating assembly and for installing the measuring rod 5. These two through holes are parallel to each other, and the distance between their central axes is equal to the distance between the central shaft axis of the rotating assembly and the axis of the circular groove at the root of the tooth groove on the gear plate. The upper part of the positioning bracket also has a longitudinal slot with pin holes on the slot wall. The moving block is installed by engaging the second cylindrical pin 24 with the pin holes on the slot wall, and the moving block can rotate around the second cylindrical pin.

[0061] like Figure 5 As shown, the movable block is made of soft material and has an L-shaped structure. It has an elongated hole on the main support arm. The elongated hole is installed by a second cylindrical pin 24 engaging with a pin hole on the groove wall. The movable block can move along the second cylindrical pin 24 through the elongated hole. The thickness of the auxiliary arm is equal to the width of the rectangular groove at the top of the tooth groove. The end of the auxiliary arm has a spherical groove with a diameter of ΦA, which can engage with the outer ball head of the spherical piston rod located in the circular groove at the root of the tooth groove. When the spherical groove at the end of the auxiliary arm is in contact with the outer ball head of the spherical piston rod located in the circular groove at the root of the tooth groove, the length direction of the elongated hole is parallel to the axis of the central axis of the rotating component, thereby driving the spherical piston rod to move along the axis of the central axis of the rotating component.

[0062] The indexing and positioning assembly includes a positioning pin seat 18, a positioning pin 19, a second compression spring 20, and a screw plug 17. The positioning pin seat has three cylindrical pin holes distributed in the same way as the three mounting holes on the positioning bracket. The positioning pin seat is then mounted on the positioning bracket using the cylindrical pins. The positioning pin seat also has a positioning stepped pin hole. The positioning pin 19, the second compression spring 20, and the screw plug 17 are sequentially installed in the positioning stepped pin hole. When the positioning pin seat is mounted on the positioning bracket, the positioning pin can position the tooth grooves in the gear plate, thereby positioning the rotating assembly. In this embodiment, the gear plate has a total of 9 tooth grooves. By designing the opening direction of the positioning stepped pin hole on the positioning pin seat to be at a 20° angle to the vertical direction, it is ensured that the positioning pin is directly against the top of the tooth groove, and the axis of the positioning pin intersects perpendicularly with the central axis of the rotating assembly.

[0063] like Figure 2 As shown, the measuring mechanism includes a digital display 21, a measuring bracket 3, and a measuring rod 5. Figure 11As shown, the measuring rod is a stepped rod, with the larger diameter section inserted into the through hole in the upper part of the positioning bracket for mounting the measuring rod, and the smaller diameter section extending axially into the circular groove at the root of the tooth groove of the gear plate. The measuring bracket has an inverted T-shaped structure, with its bottom fixed to the base plate by hexagonal bolts and positioned by cylindrical pins to ensure consistent positioning of the measuring bracket after repeated installation. The measuring bracket has a through hole in its upper part, and screw holes are opened on the sidewall of the through hole. The digital display is inserted into the through hole of the measuring bracket via a retaining spring 1 and secured by clamping screws in the screw holes. The measuring end of the digital display coaxially abuts against the end of the measuring rod, allowing the measuring rod to move axially under the action of the spherical piston rod, and the displacement is displayed on the digital display.

[0064] Furthermore, the measuring mechanism also includes a third compression spring 22 and a connecting member 4. The connecting member 4 has a stepped through hole, wherein the small diameter section is fitted with the large diameter section of the measuring rod with a small clearance, and the connecting member is fixedly connected to the measuring rod by a first cylindrical pin 23. A third compression spring is installed between the large diameter section of the stepped through hole of the connecting member and the measuring bracket, and the third compression spring ensures that the measuring rod always has a preload force in contact with the spherical piston rod.

[0065] The method for measuring the axial clearance of a spherical piston in a hydraulic plunger pump using the above-mentioned device includes the following steps:

[0066] Step 1: Insert the outer ball ends of the nine spherical piston rods on the shaft-piston assembly into the circular grooves with a diameter of ΦA at the root of the tooth grooves of the rotating assembly, so that the axis of each spherical piston rod is parallel to the axis of the central axis of the rotating assembly, and the teeth on the end face of the central axis of the rotating assembly mesh with the central teeth of the shaft-piston assembly.

[0067] Step 2: Drag the handle to the outermost position to release the quick clamping mechanism; rotate the moving block 90° counterclockwise around the second cylindrical pin to open it.

[0068] Step 3: Insert the central shaft of the rotating assembly assembled with the shaft-piston assembly into the through hole of the positioning bracket. After pushing the handle into place, rotate the handle to make the center press against the tapered hole of the shaft-piston assembly, thus reliably clamping the shaft-piston assembly. Rotate the moving block 90° clockwise around the second cylindrical pin so that the spherical groove with diameter ΦA of the moving block mates with the ball end of the spherical piston rod located in the groove at the root of the tooth groove. The shaft-piston assembly is now in the test state.

[0069] Step 4: Push the moving block away from the measuring mechanism to its limit position, clear the digital display, and then push the moving block towards the measuring mechanism to its limit position. At this time, the reading on the digital display is the axial clearance of the spherical piston rod.

[0070] Step 5: Rotate the moving block counterclockwise by 90° around the second cylindrical pin to return it to the open state; pull back the measuring rod to separate it from the outer ball head of the spherical piston rod; rotate the rotating assembly to engage the synchronous positioning pin into the top of the next tooth groove of the rotating assembly; then rotate the moving block clockwise by 90° around the second cylindrical pin to make the spherical groove of the moving block diameter ΦA engage with the outer ball head of the spherical piston rod in the tooth root groove, and release the measuring rod to make it contact the outer ball head of the spherical piston rod in the tooth root groove of the currently facing tooth again. Repeat step 4 to obtain the axial clearance of the current spherical piston rod.

[0071] Step 6: Repeat step 5 to complete the axial clearance measurement of all spherical piston rods in sequence;

[0072] Step 7: Rotate the moving block counterclockwise by 90° around the second cylindrical pin, rotate the handle to move the tip outward, remove the rotating assembly and shaft-piston assembly from the measuring tool, position the rotating assembly at the bottom, remove the shaft-piston assembly with the axis vertical, and complete the axial clearance measurement of the spherical piston of the entire product.

[0073] This invention ensures that each spherical piston rod is in the accurate measurement position during the measurement process, and also prevents damage to the spherical piston rod during the measurement process. The measuring instrument has a compact structure, is easy to use, and greatly improves measurement efficiency.

[0074] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A measuring tool for the axial clearance of a spherical piston in a hydraulic plunger pump, characterized in that: Includes a base plate, a rotating assembly, an indexing and positioning assembly, a positioning assembly, a measuring mechanism, and a quick-clamping mechanism; The quick clamping mechanism includes a fixed bracket and a center assembly; the fixed bracket is fixedly mounted on the base plate, and the center assembly is mounted on the fixed bracket and can move axially, cooperating with the rotating assembly to clamp the shaft-piston assembly; The rotating assembly consists of a central shaft and a geared disc that are fastened together. The smaller diameter section engages with a positioning bracket in the positioning assembly, mounting the rotating assembly on the positioning bracket with its stepped surface flush against the bracket wall for axial positioning of the central shaft. The larger diameter section of the central shaft has a toothed end face that engages with the central tooth of the shaft-piston assembly. The shaft-piston assembly is clamped and fixed from both sides via the central shaft and the center point. The geared disc has N evenly distributed tooth grooves, where N is the number of spherical piston rods in the shaft-piston assembly. The root of each tooth groove is a circular groove with a diameter of ΦA, where ΦA is the diameter of the outer ball end of the spherical piston rod. The upper part of the tooth groove is a rectangular groove. The outer ball end of the spherical piston rod can extend into the circular groove at the root of the tooth groove and is fixed by a moving block slot inserted from the rectangular groove. The positioning component includes a positioning bracket and a movable block. The upper part of the positioning bracket has a through hole for mounting the central shaft of the rotating component and a through hole for mounting the measuring rod. These two through holes are parallel to each other, and the distance between the central axes of the two through holes is equal to the distance between the axis of the central shaft of the rotating component and the axis of the circular groove at the root of the tooth groove of the gear plate. The upper part of the positioning bracket also has a longitudinal groove with a pin hole on the groove wall. The movable block is installed by engaging the pin hole on the groove wall with a cylindrical pin, and the movable block can rotate around the cylindrical pin. The movable block has an L-shaped structure and an elongated hole on the main support arm. The elongated hole is installed by a cylindrical pin engaging with a pin hole on the groove wall, and the movable block can move along the cylindrical pin through the elongated hole. The thickness of the auxiliary arm is equal to the width of the rectangular groove at the top of the tooth groove. The end of the auxiliary arm has a spherical groove with a diameter of ΦA, which can engage with the outer ball head of the spherical piston rod located in the circular groove at the root of the tooth groove. When the spherical groove at the end of the auxiliary arm is in contact with the outer ball head of the spherical piston rod located in the circular groove at the root of the tooth groove, the length direction of the elongated hole is parallel to the central axis of the rotating component, thereby driving the spherical piston rod to move along the central axis of the rotating component. The indexing and positioning assembly includes a positioning pin seat, a positioning pin, a compression spring, and a screw plug. The positioning pin seat is installed on the side wall of the positioning bracket. The positioning pin seat has a positioning stepped pin hole. The positioning pin, the compression spring, and the screw plug are installed in the positioning stepped pin hole in sequence. When the positioning pin seat is installed on the positioning bracket, the positioning pin can position the tooth groove in the gear plate, thereby positioning the rotating assembly. The measuring mechanism includes a digital display, a measuring bracket, and a measuring rod. The measuring rod is a stepped rod, with its larger diameter section inserted into a through hole in the upper part of the positioning bracket for mounting the measuring rod, and its smaller diameter section extending axially into a circular groove at the root of the tooth groove of the gear plate. The upper part of the measuring bracket has a through hole, and the side wall of the through hole has a screw hole. The digital display is installed in the through hole of the measuring bracket by a snap ring and is fastened by a clamping screw in the screw hole. The measuring end of the digital display is coaxially pressed against the end of the measuring rod, and the measuring rod can move axially under the action of the spherical piston rod, and the displacement is displayed by the digital display.

2. The axial clearance measuring tool for a spherical piston of a hydraulic plunger pump according to claim 1, characterized in that: The fixed bracket has an inverted T-shaped structure, with its bottom fixedly connected to the base plate. The upper part of the fixed bracket has parallel through holes, one of which is used to arrange the top component, and the other is a threaded hole used to arrange the limit screw to prevent the top component from coming off the fixed bracket.

3. The axial clearance measuring tool for a spherical piston of a hydraulic plunger pump according to claim 2, characterized in that: The center assembly includes a center, a movable sleeve, and a screw. The movable sleeve is installed in a through hole on the fixed bracket for accommodating the center assembly and has a small clearance fit with the through hole, allowing it to move axially along the through hole. The movable sleeve has a stepped through hole at its center, with the larger diameter section of the stepped through hole fitting with the center. The center fits with the larger diameter section of the stepped through hole with a small clearance, allowing it to move axially along the larger diameter section of the stepped through hole. The smaller diameter section of the stepped through hole is a threaded hole for fitting with the screw. A first compression spring 10 is located between the screw and the center. When the screw is rotated, the first compression spring 10 pushes the center, causing the center to firmly clamp the shaft-piston assembly. An elongated hole along the axial direction is opened on the side wall of the movable sleeve, and a radial through hole is located on the center. A pin is installed in the radial through hole of the center, and the pin fits with the elongated hole on the side wall of the movable sleeve to achieve axial positioning of the center. The two ends of the outer surface of the movable sleeve have radial protrusions at different circumferential positions, which fit with the fixed bracket and the limiting screw to constrain the axial movement range of the movable sleeve.

4. The axial clearance measuring tool for a spherical piston of a hydraulic plunger pump according to claim 1, characterized in that: The positioning bracket has an inverted T-shaped structure, with its bottom fixedly connected to the base plate; the middle of the positioning bracket has three mounting holes with parallel axes but not on the same plane, for mounting the indexing positioning component.

5. The axial clearance measuring tool for a spherical piston of a hydraulic plunger pump according to claim 1, characterized in that: The moving block is made of a soft material.

6. The axial clearance measuring tool for a spherical piston of a hydraulic plunger pump according to claim 1, characterized in that: When the locating pin positions the rotating component, the locating pin is directly against the top of the tooth groove, and the axis of the locating pin intersects perpendicularly with the axis of the central axis of the rotating component.

7. The axial clearance measuring tool for a spherical piston of a hydraulic plunger pump according to claim 1, characterized in that: The bottom of the fixed bracket, positioning bracket, and measuring bracket are all fixedly connected to the base plate by hexagonal bolts and positioned by cylindrical pins to ensure that the bracket positions are consistent after repeated installation.

8. The axial clearance measuring tool for a spherical piston of a hydraulic plunger pump according to claim 1, characterized in that: The measuring mechanism also includes a compression spring and a connector; the connector has a stepped through hole, wherein the small diameter section is fitted with the large diameter section of the measuring rod with a small clearance, and the connector is fixedly connected to the measuring rod by a cylindrical pin. A third compression spring is installed between the large diameter section of the stepped through hole of the connector and the measuring bracket, and the third compression spring ensures that the measuring rod always has a preload force in contact with the spherical piston rod.

9. A method for measuring the axial clearance of a spherical piston in a hydraulic plunger pump, characterized in that: The measurement using the measuring instrument described in any one of claims 1 to 8 includes the following steps: Step 1: Insert the outer ball end of the spherical piston rod on the shaft-piston assembly into the circular groove with diameter ΦA at the root of the tooth groove of the rotating assembly, so that the axis of each spherical piston rod is parallel to the axis of the central axis of the rotating assembly, and the teeth on the end face of the central axis of the rotating assembly mesh with the central teeth of the shaft-piston assembly. Step 2: Drag the handle to the outermost position to release the quick clamping mechanism; rotate the moving block around the cylindrical pin to open it. Step 3: Insert the central shaft of the rotating assembly assembled with the shaft-piston assembly into the through hole of the positioning bracket. After pushing the handle into place, rotate the handle to make the center press against the tapered hole of the shaft-piston assembly, thus reliably clamping the shaft-piston assembly. Rotate the moving block around the cylindrical pin so that the spherical groove with diameter ΦA of the moving block mates with the ball end of the spherical piston rod located in the groove at the root of the tooth groove. The shaft-piston assembly is now in the test state. Step 4: Push the moving block away from the measuring mechanism to its limit position, clear the digital display, and then push the moving block towards the measuring mechanism to its limit position. At this time, the reading on the digital display is the axial clearance of the spherical piston rod. Step 5: Rotate the moving block around the cylindrical pin to return it to the open state; pull back the measuring rod to separate it from the outer ball head of the spherical piston rod; rotate the rotating assembly to engage the synchronous positioning pin into the top of the next tooth groove of the rotating assembly; rotate the moving block around the cylindrical pin again to make the spherical groove with diameter ΦA of the moving block engage with the outer ball head of the spherical piston rod in the tooth root groove, and release the measuring rod to make it contact the outer ball head of the spherical piston rod in the tooth root groove of the currently facing tooth again. Repeat step 4 to obtain the axial clearance of the current spherical piston rod. Step 6: Repeat step 5 to complete the axial clearance measurement of all spherical piston rods in sequence; Step 7: Rotate the moving block around the cylindrical pin, rotate the handle to move the tip outward, remove the rotating assembly and the shaft-piston assembly, position the rotating assembly at the bottom, remove the shaft-piston assembly with the axis vertical, and complete the axial clearance measurement of the spherical piston of the entire product.

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