Press-fit tool for lead screw and bearing

Abstract

The utility model discloses a press-fit tool for a lead screw and a bearing. The press-fit tool aims to overcome the defects that an existing press-fit tool is insufficient in deviation correction and low in inverted assembly precision. The guide device comprises a guide shaft, a cover plate, a middle guide plate, a press-fit guide plate, a bearing fixing seat, a pressure head and a spring, the middle guide plate and the press-fit guide plate are both provided with limiting grooves through which a lead screw body can pass, and the forming directions of the limiting grooves of the middle guide plate and the press-fit guide plate are different. The lead screw is rectified through the limiting grooves of the middle guide plate and the press-fit guide plate which are arranged in different directions, the press-fit precision can be improved, and the deflection problem is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of tooling positioning, more specifically, it relates to a press-fitting tool for screw rod and bearing. BACKGROUND

[0002] As a kind of precision liquid delivery equipment, injection pump is widely used in medical treatment, laboratory and industrial production, and one of its core technologies is the design and assembly of transmission system. The existing injection pump usually adopts step motor to drive screw rod, and the rotation of screw rod accurately transmits motion to syringe piston, so as to realize the accurate injection of liquid. In this transmission structure, the press-fitting quality between screw rod and bearing at both ends directly affects the working accuracy, stability and service life of the overall system.

[0003] The current assembly tool for screw rod and bearing lacks position control of shaft, so that the screw rod is assembled into the bearing in a skewed posture, resulting in inconsistent stress of each part of the bearing and limiting the accuracy of the injection pump. The present application aims to improve it. UTILITY MODEL CONTENT

[0004] The utility model overcomes the insufficient deviation correction of the existing press-fitting tool, and provides a press-fitting tool for screw rod and bearing, which can improve the precision of press-fitting and solve the skew problem through the limiting grooves of the oppositely arranged middle guide plate and press-fitting guide plate.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0006] A press-fitting tool for screw rod and bearing, the screw rod includes a screw rod body and shaft shoulders at both ends of the screw rod body, comprising

[0007] A plurality of guide shafts arranged in the height direction, the guide shafts are fixedly connected to the bottom plate;

[0008] A cover plate, a middle guide plate and a press-fitting guide plate are slidingly connected to the guide shafts, the cover plate, the middle guide plate and the press-fitting guide plate are sequentially inserted and slidingly connected to the guide shafts from high to low, a shaft sleeve is further sleeved between the cover plate, the middle guide plate and the press-fitting guide plate, the upper and lower ends of the shaft sleeve are respectively attached to the adjacent two plates, the middle guide plate and the press-fitting guide plate are both provided with limiting grooves through which the screw rod body can pass, and the cover plate is provided with a cover plate opening hole matching the shaft shoulder;

[0009] A bearing fixing seat is fixedly connected to the bottom plate, and the bearing fixing seat is provided with a fixing hole matching the bearing;

[0010] A pressing head is provided with a pressing column, and the pressing column is inserted into the cover plate opening hole and attached to the end of the screw rod;

[0011] The spring is mounted on the guide shaft and positioned between the press-fit guide plate and the base plate;

[0012] The limiting grooves of the intermediate guide plate and the press-fit guide plate are opened in different directions.

[0013] The press-fit fixture is used to connect the lead screw and bearings. This application's press-fit fixture supports the sequential installation of bearings at both ends of the lead screw. An intermediate guide plate and a press-fit guide plate are used to limit the lead screw's movement, preventing skewing. The limiting grooves of the intermediate guide plate and the press-fit guide plate allow the lead screw to pass through. This application sets the two limiting grooves in opposite directions, thereby solving the lead screw skewing problem.

[0014] This application supports the installation of bearings at both ends of the lead screw. For tooling with only one bearing mounting base, the lead screw and bearing need to be installed in two separate steps. Once a bearing has been installed at one end of the lead screw, it is not necessary to remove the press-fit guide plate. The lead screw can be removed through the limiting groove, reducing the workload of repeatedly disassembling the tooling.

[0015] Preferably, the limiting grooves of the intermediate guide plate and the press-fit guide plate are orthogonal. Setting the limiting groove opening direction to orthogonal reduces the component force in the deflection direction, thus reducing damage to the threads on the lead screw.

[0016] Preferably, the end of the limiting groove has a semi-circular groove wall, the diameter of which is adapted to the diameter of the lead screw body. The groove wall fits snugly against the lead screw body, thereby limiting the lead screw deflection.

[0017] Preferably, a lead screw nut is threaded onto the lead screw body, and a locking pin is fixedly connected to the lead screw nut. The press-fit guide plate has at least two positioning pins arranged along the height direction, and the locking pin has a locking pin positioning hole adapted to the positioning pin. The positioning pin is inserted into the locking pin positioning hole. The cooperation between the positioning pin and the locking pin positioning hole further improves the press-fit accuracy.

[0018] Preferably, the press-fit guide plate is provided with a nut positioning hole with the same shape as the lead screw nut. The lead screw nut is inserted into the nut positioning hole, and the positioning pin is inserted into the locking pin positioning hole, thereby further improving the press-fit accuracy.

[0019] Preferably, the width of the limiting groove gradually decreases along the direction from the opening to the end of the limiting groove. A larger opening in the limiting groove facilitates the insertion or removal of the lead screw.

[0020] Preferably, the edge of the fixing hole abuts against the inner ring of the bearing, and the inner diameter of the fixing hole is greater than or equal to the inner diameter of the inner ring of the bearing.

[0021] Preferably, the top of the pressure head is a curved surface. This structure supports manual pressing, and the curved surface reduces pressure on the hand.

[0022] Compared with the prior art, the utility model has the beneficial effects that:

[0023] (1) through the limit slot of the intermediate guide plate and the press-fit guide plate of different directions, the precision of press-fit can be improved, and the problem of deflection is solved;

[0024] (2) the tooling supports assembling bearings on both ends of the lead screw, and the production efficiency is higher.

[0025] (3) the lead screw and the lock pin in the application are pre-assembled through the screw nut, and the lock pin positioning hole on the lock pin is used for auxiliary positioning, and the positioning precision is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is the axonometric view of the utility model;

[0027] Figure 2 is the cross-sectional view of the utility model for installing the first bearing;

[0028] Figure 3 is the explosion view of the utility model;

[0029] Figure 4 is the lead screw assembly of the utility model;

[0030] Figure 5 is the cross-sectional view of the utility model for installing the second bearing;

[0031] In the drawings:

[0032] Lead screw body 1, shaft shoulder 2, screw nut 3, lock pin 4, guide shaft 5, bottom plate 6, cover plate 7, intermediate guide plate 8, press-fit guide plate 9, bearing fixing seat 10, pressing head 11, spring 12, shaft sleeve 13, cover plate opening 14, pressure column 15, groove wall 16, lock pin positioning hole 17, positioning column 18, limit slot 19, bearing 20, fixing hole 21, nut positioning hole 22. DETAILED DESCRIPTION

[0033] The present disclosure will be further described below in conjunction with the drawings and examples.

[0034] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs.

[0035] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0036] In the present disclosure, the terms such as "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "side", "bottom", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only a relationship word determined for the convenience of describing the structural relationship of the components or elements of the present disclosure, and cannot be understood as a limitation on the present disclosure.

[0037] In the present disclosure, the terms such as "fixedly connected", "connected", "connected" and the like should be understood broadly, which means that it can be fixedly connected, integrally connected or detachably connected; it can be directly connected or indirectly connected through an intermediate medium. For relevant researchers or technicians in the art, the specific meaning of the above terms in the present disclosure can be determined according to the specific circumstances, and cannot be understood as a limitation on the present disclosure.

[0038] Embodiment:

[0039] A press-fit tool for a lead screw and a bearing 20, as shown in Figure 1 The tool is used to press-fit bearings 20 at both ends of a lead screw, which includes a lead screw body 1 and a shaft shoulder 2 at both ends of the lead screw body 1. A lead screw nut 3 is threadedly connected to the lead screw body 1, and a locking pin 4 is fixedly connected to the lead screw nut 3. The lead screw nut 3 is fixedly connected to the locking pin 4 by screws.

[0040] Referring to Figure 3As shown, the press-fitting tool comprises guide shafts 5, a bottom plate 6, a cover plate 7, an intermediate guide plate 8, a press-fitting guide plate 9, a bearing fixing seat 10, a press head 11 and a spring 12. The guide shafts 5 are four in number, and the connecting lines of the axes thereof form a rectangle. The guide shafts 5 are fixedly connected to the bottom plate 6 through fasteners. The cover plate 7, the intermediate guide plate 8 and the press-fitting guide plate 9 are provided with guide holes corresponding to the guide shafts 5. The guide shafts 5 are inserted into the guide holes. In some embodiments, the inner walls of the guide holes are fixedly connected with bushings, and the guide shafts 5 are slidably connected with the bushings. Each plate can be slid out of the guide shaft 5 from the top of the guide shaft 5. The cover plate 7, the intermediate guide plate 8 and the press-fitting guide plate 9 are sequentially inserted on the guide shaft 5 from high to low. A shaft sleeve 13 is further sleeved between the cover plate 7, the intermediate guide plate 8 and the press-fitting guide plate 9. The upper and lower ends of the shaft sleeve 13 are respectively attached to the adjacent two plates. The bearing fixing seat 10 is fixedly connected to the bottom plate 6 through fasteners. The bearing fixing seat 10 is provided with a fixing hole 21 matched with a bearing 20. Specifically, the hole of the fixing hole 21 abuts against the inner ring of the bearing 20, and the inner diameter of the fixing hole 21 is greater than or equal to the inner diameter of the inner ring of the bearing 20. The spring 12 is sleeved on the guide shaft 5 and arranged between the press-fitting guide plate 9 and the bottom plate 6. The intermediate guide plate 8 and the press-fitting guide plate 9 are both provided with a limiting slot 19 through which the screw body 1 can pass. The cover plate 7 is provided with a cover plate opening 14 matched with the shaft shoulder 2. The press head 11 is provided with a pressing column 15 inserted into the cover plate opening 14 and attached to the end of the screw. The limiting slots 19 of the intermediate guide plate 8 and the press-fitting guide plate 9 are arranged in different directions.

[0041] In some embodiments, the limiting slots 19 of the intermediate guide plate 8 and the press-fitting guide plate 9 are arranged in orthogonal directions. Arranging the limiting slots 19 in orthogonal directions can resist the component force of the deflection direction, reducing the damage to the screw thread.

[0042] The limiting slot 19 is provided with a semicircular slot wall 16 with a diameter adapted to the diameter of the screw body 1. The slot wall 16 is attached to the screw body 1, thereby limiting the deflection of the screw. The width of the limiting slot 19 gradually decreases along the direction from the slot opening of the limiting slot 19 to the end of the limiting slot 19. The opening of the limiting slot 19 is large enough for the screw to be put in or taken out.

[0043] Referring to Figure 4 As shown, the press-fitting guide plate 9 is provided with at least two positioning columns 18 arranged in the height direction. The locking pin 4 is provided with a locking pin positioning hole 17 matched with the positioning column 18. The positioning column 18 is inserted into the locking pin positioning hole 17. Through the cooperation of the positioning column 18 and the locking pin positioning hole 17, the precision of the press-fitting is further improved. The press-fitting guide plate 9 is provided with a nut positioning hole 22 with the same shape as the screw nut 3. The screw nut 3 is inserted into the nut positioning hole 22. The positioning column 18 is inserted into the locking pin positioning hole 17, thereby further improving the precision of the press-fitting.

[0044] The top of the indenter 11 is an arc-shaped curved surface. This structure supports manual pressing, and the arc-shaped curved surface structure can reduce the pressure on the human hand.

[0045] The press-fitting tooling is used to connect the lead screw and the bearing 20. The press-fitting tooling of the present application supports installing the bearings 20 at both ends of the lead screw in sequence. The intermediate guide plate 8 and the press-fitting guide plate 9 are used to limit the position of the lead screw to prevent the skew problem of the lead screw. The limiting grooves 19 of the intermediate guide plate 8 and the press-fitting guide plate 9 are used for the lead screw to pass through. The present application sets the opening directions of the two limiting grooves 19 in opposite directions, thus solving the skew problem of the lead screw.

[0046] Since the present application supports installing the bearings 20 at both ends of the lead screw. For the tooling with only one bearing fixing seat 10, it is necessary to install the lead screw and the bearing 20 in two times. After a bearing 20 has been installed at one end of the lead screw, there is no need to remove the press-fitting guide plate 9, and the lead screw can be removed from the notch of the limiting groove 19, reducing the labor intensity of repeatedly disassembling the tooling.

[0047] See Figure 2 As shown, when assembling the first bearing 20, remove the intermediate guide plate 8 and the cover plate 7 from the guide shaft 5, place the first bearing 20 into the fixing hole 21 of the bearing fixing seat 10 for positioning, put the lead screw, the lead screw nut 3 and the locking pin 4 (hereinafter referred to as the lead screw assembly) along the notch of the limiting groove 19 of the press-fitting guide plate 9, make the lead screw fit with the groove wall 16 at the bottom of the limiting groove of 19, insert the positioning column 18 into the locking pin positioning hole 17, then reinstall the intermediate guide plate 8, the cover plate 7 and the bushing 13, press down the indenter 11 by a press or manually, and after resetting, reset under the action of the spring 12. At this time, the shoulder 2 of the lead screw is inserted into the inner ring of the first bearing 20 and is in interference fit with it.

[0048] See Figure 4 As shown, when assembling the second bearing 20, remove the intermediate guide plate 8 and the cover plate 7 from the guide shaft 5, remove the lead screw assembly along the notch of the limiting groove 19, invert the assembly and put it into the limiting groove 19 of the press-fitting guide plate 9, make the lead screw fit with the groove wall 16, put the lead screw nut into the nut positioning hole 22, insert the positioning column 18 into the locking pin positioning hole 17, reinstall the intermediate guide plate 8, the cover plate 7 and the bushing 13, press down the indenter 11 by a press or manually, and after resetting, reset under the action of the spring 12. At this time, the shoulder 2 of the lead screw is inserted into the inner ring of the second bearing 20 and is in interference fit with it, completing the press-fitting work.

[0049] The above embodiments are only preferred solutions of the present utility model, and do not impose any form of limitation on the present utility model. There are other variants and modifications without exceeding the technical solutions recorded in the claims.

Claims

1. A press-fit fixture for a lead screw and a bearing, wherein the lead screw includes a lead screw body and shoulders at both ends of the lead screw body, characterized in that, include Several guide shafts are arranged along the height direction, and the guide shafts are fixedly connected to the base plate; A cover plate, an intermediate guide plate, and a press-fit guide plate are slidably connected to a guide shaft. The cover plate, intermediate guide plate, and press-fit guide plate are sequentially inserted into the guide shaft from high to low and are slidably connected to the guide shaft. A bushing is also fitted between the cover plate, intermediate guide plate, and press-fit guide plate. The upper and lower ends of the bushing are respectively in contact with the two adjacent plates. The intermediate guide plate and the press-fit guide plate are both provided with limiting grooves that allow the lead screw body to pass through. The cover plate is provided with a cover plate opening that matches the shaft shoulder. The bearing mounting base is fixedly connected to the base plate. The bearing mounting base is provided with mounting holes that match the bearing. The pressure head is equipped with a pressure column, which is inserted into the opening of the cover plate and fits against the end of the lead screw; The spring is mounted on the guide shaft and positioned between the press-fit guide plate and the base plate; The limiting grooves of the intermediate guide plate and the press-fit guide plate are opened in different directions.

2. The press-fit fixture for a lead screw and bearing according to claim 1, characterized in that, The limiting grooves of the intermediate guide plate and the pressing guide plate are orthogonal in direction.

3. The press-fit fixture for lead screw and bearing according to claim 2, characterized in that, The end of the limiting groove is provided with a semi-circular groove wall, the diameter of which is adapted to the diameter of the lead screw body.

4. The press-fit fixture for a lead screw and bearing according to claim 3, characterized in that, The width of the limiting groove gradually decreases along the direction from the opening of the limiting groove to the end of the limiting groove.

5. The press-fit fixture for a lead screw and bearing according to claim 1, characterized in that, The lead screw body is threaded with a lead screw nut, and the lead screw nut is fixedly connected with a locking pin. The press-fit guide plate is provided with at least two positioning pins arranged along the height direction. The locking pin is provided with a locking pin positioning hole adapted to the positioning pin, and the positioning pin is inserted into the locking pin positioning hole.

6. The press-fit fixture for a lead screw and bearing according to claim 5, characterized in that, The press-fit guide plate is provided with a nut positioning hole with the same shape as the lead screw nut, and the lead screw nut is inserted into the nut positioning hole.

7. The press-fit fixture for lead screw and bearing according to claim 1, characterized in that, The edge of the fixing hole abuts against the inner ring of the bearing, and the inner diameter of the fixing hole is greater than or equal to the inner diameter of the inner ring of the bearing.

8. A press-fit fixture for a lead screw and a bearing according to any one of claims 1 to 7, characterized in that, The top of the pressure head is a curved surface.

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