Coupling for lead screw

Abstract

The utility model relates to the technical field of lead screw transmission, in particular to a coupling for a lead screw, which comprises a lead screw and a screw head which are in threaded connection, one end of the screw head is provided with a cylindrical opening cavity, one end of the lead screw is sleeved with a connecting rod, one end of the connecting rod is provided with an annular boss, and the annular boss is arranged in the cylindrical opening cavity. An inner gasket is arranged at the position where the annular boss is connected with the bottom of the barrel-shaped opening cavity, a gland with threads at one end is arranged at an opening of the barrel-shaped opening cavity, the gland is in threaded connection with the screw head, and the annular boss is connected between the gland and the inner gasket in a pressed mode. The transmission mechanism is good in coaxiality, simple in structure, small in transmission inertia, low in noise and capable of well achieving accurate transmission.

Description

Technical Field

[0001] The utility model relates to the technical field of screw rod transmission, in particular to a coupling for a screw rod. Background Art

[0002] Screw pairs are often used to convert rotary motion into linear motion. Current stepper motor transmissions either use traditional couplings, which are too large and inaccurate for use in precision instruments. Or they have poor coaxiality, causing large vibrations and noise in the equipment, affecting transmission accuracy. Or they have complex structures, which are time-consuming and labor-intensive to process and install.

[0003] When the screw pair is used in precision instruments, vibration noise is often generated, affecting the normal operation of the equipment. In the prior art, a Chinese patent application with publication number CN213744774U discloses a trapezoidal screw pair noise reduction structure, which improves the noise reduction and pressure resistance of the screw pair by cooperating with two sound insulation sponge layers and noise reduction and sound insulation rubber layers, and two mounting plates drive four connecting support rods through four hinges respectively, and the four connecting support rods drive four sliders through four hinges respectively, and the four sliders cooperate with four slide seats and four first springs respectively. However, this structure is complex, has a high failure rate, and increases manufacturing costs, making it difficult to promote and use. A Chinese patent application with publication number CN207145556U discloses a screw pair noise reduction structure, which achieves the purpose of reducing the noise of the screw pair by evenly distributing a number of threaded holes and noise reduction slots in the circumferential direction of the end face of one side of the nut portion, and providing shock-absorbing and sound-absorbing materials in the noise reduction slots. However, the scheme has a plurality of noise reduction slots and threaded holes staggered, which also increases the assembly and manufacturing costs, places high requirements on assembly accuracy, and increases the manufacturing costs. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a coupling for a screw rod in view of the above-mentioned technical deficiencies. A cylindrical opening cavity is provided at one end of the screw head, and the connection between the screw head and the connecting rod is achieved by crimping an annular boss at one end of the connecting rod through an end cover, thereby solving the problems of poor coaxiality, high equipment noise and poor transmission accuracy of the existing coupling.

[0005] In order to solve the above technical problems, the technical solution adopted by the utility model is: a coupling for a screw, comprising a screw and a screw head connected by a thread, one end of the screw head is provided with a cylindrical opening cavity, one end of the screw is sleeved with a connecting rod, one end of the connecting rod is provided with an annular boss, the annular boss is arranged inside the cylindrical opening cavity, an inner gasket is provided at the position where the annular boss connects with the bottom of the cylindrical opening cavity, a pressure cover with a thread on one end is provided at the opening of the cylindrical opening cavity, the pressure cover is threadedly connected to the screw head, and the annular boss is crimped between the pressure cover and the inner gasket.

[0006] To further optimize the technical solution, an outer gasket is provided at the outer end cover of the gland, and the outer gasket is crimped between the end cover and the end of the thread head.

[0007] To further optimize the technical solution, a limiting piece is provided at the end of the wire head.

[0008] To further optimize the technical solution, the axial end faces at both ends of the annular boss are perpendicular to the rotation axis of the connecting rod.

[0009] To further optimize the technical solution, the axial end face of the annular boss is provided with a tapered surface.

[0010] To further optimize the technical solution, a conical cavity is provided on the inner side of the end cover, and a conical pad is provided between the conical cavity and the annular boss.

[0011] To further optimize the technical solution, the radial inner side of one end of the inner gasket is connected to the annular boss, and the radial outer side of the inner gasket is connected to the inner wall of the cylindrical opening cavity.

[0012] Compared with the prior art, the utility model has the following advantages: 1. The utility model has good coaxiality, simple structure, small transmission inertia, low noise, and can well realize precise transmission; 2. It can perform well in precise transmission of stepper motors, etc., and is easy to install. The gland, thread head, connecting rod, and connecting rod are screwed together through coaxial threads, which can fully ensure the coaxiality of the transmission and can well meet the requirements of precise transmission of stepper motors, etc. in precision instruments; 3. The manufacturing cost is low, and it is particularly suitable for use in precise transmission of stepper motors and servo motors; 4. The overload capacity of transmitting torque is strong, and the elastic gasket is used to achieve buffering between the two, which can provide the degree of tightening of the gland to adjust the transmission capacity of the coupling; 5. The connecting rod can be moved up and down without rotating through the limit plate. The limit plate and the entire coupling are integrated together, and the limit plate cannot rotate, so that the connecting rod cannot rotate but can only move up and down, which can better transmit axial movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the external structure of a coupling for a screw rod;

[0014] Figure 2 It is a cross-sectional view of a coupling for a screw rod;

[0015] Figure 3 for Figure 2 A local enlarged schematic diagram of the middle A;

[0016] Figure 4 The present invention is a partial view of a second embodiment of a coupling for a screw at the screw head.

[0017] In the figure: 1, connecting rod; 11, annular boss; 2, screw rod; 3, pressure cover; 31, end cover; 32, tapered cavity; 4, screw head; 41, cylindrical opening cavity; 5, outer gasket; 6, inner gasket; 7, limit plate; 8, tapered gasket. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model is further described in detail below in conjunction with the reference drawings of specific embodiments. It should be understood that these descriptions are only exemplary and are not intended to limit the scope of the utility model. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the utility model.

[0019] Unless otherwise defined, the technical terms or scientific terms used herein shall have the usual meanings understood by persons with ordinary skills in the field to which the utility model belongs. Similar words such as "one", "an" or "the" used in the specification and claims of the utility model patent application do not indicate a quantitative limitation, but rather indicate the existence of at least one. Similar words such as "include" or "comprise" mean that the elements or objects appearing before "include" or "comprise" include the elements or objects listed after "include" or "comprise" and their equivalents, and do not exclude other elements or objects. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0020] Embodiment 1, combined with Figure 1-3 As shown, a coupling for a screw comprises a screw 2 and a screw head 4 connected by threads, one end of the screw head 4 is provided with a cylindrical opening cavity 41, one end of the screw 2 is coaxially sleeved with a connecting rod 1, an annular boss 11 is provided at the outer wall of one end of the connecting rod 1, the annular boss 11 is arranged inside the cylindrical opening cavity 41, an inner gasket 6 is provided at the position where the annular boss 11 and the bottom of the cylindrical opening cavity 41 are connected, a gland 3 with a thread at one end is provided at the opening of the cylindrical opening cavity 41, the gland 3 is threadedly connected to the cylindrical opening cavity 41 inside the screw head 4, and the annular boss 11 is crimped between the gland 3 and the inner gasket 6. An outer end cap 31 of the gland 3 is provided with an outer gasket 5, and the outer gasket 5 is crimped between the end cap 31 and the end of the screw head 4. A limit plate 7 is provided at the end of the screw head 4, and the limit plate 7 is sleeved between the gland 3 and the screw head 4.

[0021] When using, combine Figure 1-3As shown, the screw rod 2 is driven to rotate around the axis through a rotating mechanism, and the thread head 4 is guided by the limit plate 7 to achieve linear movement along the screw rod 2. The connecting rod 1 and the thread head 4 are linked by crimping the pressure cover 3 and the cylindrical opening 41 at the annular boss 11. The transmission of vibration noise is reduced by the provision of an inner gasket 6 and an outer gasket 5. The structure is simple, and the manufacturing and assembly difficulties are low, so it is suitable for wide promotion and application.

[0022] Embodiment 2, combined with Figure 4 As shown, a coupling for a screw rod is different from the first embodiment in that one or both ends of the two axial end faces of the annular boss 11 are respectively tapered. When the end face of the annular boss 11 that is connected to the end cover 31 is tapered, an annular tapered cavity 32 is provided on the radial inner side of the end cover 31, and a tapered gasket 8 is provided between the tapered cavity 32 and the annular boss 11, the radial inner side of one end of the inner gasket 6 is connected to the annular boss 11, the end of the inner gasket 6 away from the annular boss 11 is connected to the bottom of the cylindrical opening cavity 41, and the radial outer side of the inner gasket 6 is abutted against the inner wall of the cylindrical opening cavity 41.

[0023] When in use, by setting the end face of the annular boss 11 to a cone, the coaxiality of the connecting rod 1 and the thread head 4 can be further ensured when the end cover 31 is tightened, and the rotation conduction of the thread head 4 is reduced through the combined action of the inner gasket 6, the outer gasket 5 and the conical gasket 8.

[0024] It should be understood that the above specific embodiments of the present invention are only used to illustrate or explain the principles of the present invention, and do not constitute a limitation on the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc. made without departing from the spirit and scope of the present invention should be included in the protection scope of the present invention. In addition, the claims attached to the present invention are intended to cover all changes and modifications that fall within the scope and boundaries of the attached claims, or the equivalent forms of such scope and boundaries.

Claims

1. A coupling for a screw rod, comprising a screw rod (2) and a screw head (4) connected by threads, characterized in that: A cylindrical opening cavity (41) is provided at one end of the thread head (4), a connecting rod (1) is sleeved at one end of the threaded rod (2), an annular boss (11) is provided at one end of the connecting rod (1), the annular boss (11) is arranged inside the cylindrical opening cavity (41), an inner gasket (6) is provided at the position where the annular boss (11) connects with the bottom of the cylindrical opening cavity (41), a pressure cover (3) with a thread at one end is provided at the opening of the cylindrical opening cavity (41), the pressure cover (3) is threadedly connected to the thread head (4), and the annular boss (11) is crimped between the pressure cover (3) and the inner gasket (6).

2. A coupling for a screw rod according to claim 1, characterized in that: An outer gasket (5) is provided at the outer end cover (31) of the gland (3), and the outer gasket (5) is crimped between the end cover (31) and the end of the thread head (4).

3. A coupling for a screw rod according to claim 1, characterized in that: A limiting piece (7) is provided at the end of the wire head (4).

4. A coupling for a screw rod according to claim 2, characterized in that: The axial end surfaces at both ends of the annular boss (11) are perpendicular to the rotation axis of the connecting rod (1).

5. A coupling for a screw rod according to claim 2, characterized in that: The axial end surface of the annular boss (11) is provided with a tapered surface.

6. A coupling for a screw rod according to claim 4, characterized in that: A conical cavity (32) is provided on the inner side of the end cover (31), and a conical pad (8) is provided between the conical cavity (32) and the annular boss (11).

7. A coupling for a screw rod according to claim 4, characterized in that: The radial inner side of one end of the inner gasket (6) is connected to the annular boss (11), and the radial outer side of the inner gasket (6) is connected to the inner wall of the cylindrical opening cavity (41).

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