A screw transmission device in a sine mechanism

Abstract

The present invention relates to a screw transmission device in a sine mechanism, comprising a fixed seat, two bearing seats respectively installed at the front and rear ends of the fixed seat, two guide pillars, a nut slider and a screw. The two ends of the screw are installed on the two bearing seats, the nut slider is screwed on the screw, the nut slider is provided with a split groove, the nut slider is provided with an adjustment screw connecting the front and rear end surfaces of the split groove, the nut slider is also provided with guide pillar holes located on both sides of the internal threaded hole, the guide pillar is installed in the guide pillar hole, the guide pillar and the guide pillar hole are slidably matched, one end of the guide pillar is matched with one of the bearing seats by an axial hole, and then locked by a set screw installed on the top of the bearing seat, and the top of the other end of the guide pillar is connected to a screw installed on the other bearing seat. The present invention solves the technical defect of poor wavelength positioning repeatability of the grating monochromator, and effectively improves the detection index of the atomic absorption spectrophotometer.

Description

Technical Field

[0001] The invention relates to a screw transmission device in a sine mechanism, in particular to a screw transmission device in a grating monochromator sine mechanism, and belongs to the technical field of analytical testing instruments. Background Art

[0002] As an instrument for analyzing and testing the environment, metal semiconductors, and petrochemical polymer materials, atomic absorption spectrophotometers are widely used in the fields of medicine, biology, and pharmacy. As the core component of atomic absorption spectrophotometers, the performance of monochromator directly affects the detection indicators of atomic absorption spectrophotometers.

[0003] The sine mechanism is a transmission mechanism that converts the sinusoidal relationship between the wavelength of light at the exit slit of the grating monochromator and the grating rotation angle into a linear relationship. With the improvement of the detection index of the atomic absorption spectrophotometer, the requirements for the spectral analysis of the grating monochromator are getting higher and higher. After the stepper motor drives the lead screw to rotate, it is usually required that the wavelength change at the exit slit of the grating monochromator caused by each step pulse received by the stepper motor is 0.01nm. This puts extremely high requirements on the transmission accuracy of the lead screw. Generally, the cumulative error of the transmission lead screw within the total length range is required to be no more than 10μm. If all degrees of freedom of the nut slider other than the axial direction of the lead screw are not completely restricted, the atomic absorption spectrophotometer will be inaccurate when looking for the maximum value of light energy absorption, or the consistency of wavelength positioning within a small wavelength range will be poor. In addition, the matching clearance between the lead screw and the nut slider needs to be reasonably eliminated to ensure the transmission accuracy of the lead screw. Therefore, trying to find a lead screw transmission device that can not only eliminate the lead screw transmission clearance, but also completely limit all degrees of freedom of the slider in the lead screw device except the axial direction, and will not cause the driving torque of the stepper motor to increase too much has become a feasible solution to improve the performance indicators of the grating monochromator. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a screw transmission device in a sinusoidal mechanism, which can effectively reduce the fitting clearance between the screw and the nut slider, and can completely limit all degrees of freedom of the nut slider in the screw device except along the axial direction.

[0005] In order to solve the above problems, the technical solution adopted by the present invention is as follows:

[0006] A screw transmission device in a sine mechanism comprises a fixed seat, two bearing seats respectively mounted at the front and rear ends of the fixed seat, two guide pillars, a nut slider and a screw.

[0007] The two ends of the screw rod are respectively mounted on two bearing seats through bearings, the nut slider is screwed on the screw rod, the nut slider is provided with a split groove penetrating the cross section of the internal threaded hole, the nut slider is provided with an adjusting screw connecting the front and rear end surfaces of the split groove, and the adjusting screw is located above the internal threaded hole.

[0008] The nut slider is also provided with guide post holes located on both sides of the internal threaded hole. The guide posts are installed in the corresponding guide post holes. The guide posts and the guide post holes are slidingly matched. One end of the guide post is matched with the shaft hole of one of the bearing seats and then locked by a set screw installed on the top of the bearing seat. The end face of the other end of the guide post is connected to a screw horizontally installed on the other bearing seat.

[0009] In the screw transmission device of the above-mentioned sine mechanism, the split groove divides the internal thread hole of the nut slider into two parts, front and rear. The width of the split groove along the axial direction is adjusted by rotating the adjusting screw to eliminate the matching clearance between the screw and the nut slider to ensure the transmission accuracy of the screw; the sliding fit between the guide post hole and the guide post is used to limit all degrees of freedom of the slider nut except the axial movement of the guide post. The parallelism of the two guide posts within the entire stroke range can be fine-tuned by connecting the screw to one end of the guide post to ensure the transmission accuracy of the entire stroke.

[0010] Furthermore, the nut slider is provided with two positioning screws above the internal threaded hole, and the two positioning screws are symmetrically arranged on both sides below the adjusting screw, and the positioning screws pass through the split groove from the outside to the inside and press against the end surface inside the split groove. The positioning screws cooperate with the adjusting screws to prevent the width of the split groove from changing slightly during the rotation of the screw rod, so that the transmission accuracy of the screw rod is further improved.

[0011] Further, as a preference, the axes of the two guide post holes are at the same height as the axis of the internal threaded hole, so that it is more convenient to observe the parallelism between the two guide posts and the screw rod.

[0012] Furthermore, both ends of the bearing seat are mounted on the fixing seat by means of fixing screws, flat washers and elastic washers.

[0013] Further, according to experimental requirements, the shape of the nut slider is T-shaped.

[0014] In summary, compared with the prior art, the beneficial effects of the present invention are:

[0015] The present invention provides a screw transmission device in a sine mechanism, which can not only eliminate the screw transmission gap, completely limit all degrees of freedom of the nut slider in the screw device except the axial direction, but also ensure the parallelism of the guide column in the entire stroke range. The technical defect of poor wavelength positioning repeatability of the grating monochromator is solved, and the detection index of the atomic absorption spectrophotometer is effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a schematic diagram of an explosion structure according to an embodiment of the present invention.

[0017] Figure 2 The figure is a schematic structural diagram of a nut slider according to an embodiment of the present invention.

[0018] Figure 3 for Figure 2 Cross-sectional view at AA in the middle.

[0019] Figure 4 for Figure 2 Partial cross-section of the top view.

[0020] Figure 5 It is a schematic diagram of an assembly of an embodiment of the present invention.

[0021] Figure 6 The figure is a schematic diagram of the installation of the guide column and the bearing seat involved in one embodiment of the present invention.

[0022] Figure 7 The figure is a schematic diagram of the position of the nut slider when adjusting the parallelism of the guide column according to an embodiment of the present invention.

[0023] In the figure: 11a is the adjusting screw installation hole, and 12a is the positioning screw installation hole. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. According to the following description, the purpose, technical solutions and advantages of the present invention will become clearer. It should be noted that the described embodiments are preferred embodiments of the present invention, rather than all embodiments.

[0025] Example

[0026] Combination Figures 1 to 4 As shown, a screw transmission device in a sine mechanism comprises a fixed seat 1, two bearing seats 2 respectively mounted at the front and rear ends of the fixed seat 1, two guide pillars 4, a nut slider 5 and a screw 6. Both ends of the bearing seat are mounted on the fixed seat 1 by fixing screws 8, flat washers 9 and elastic washers 10.

[0027] The two ends of the screw rod 6 are respectively mounted on the bearing seats 2 at the two ends through bearings 7. The nut slider 5 is screwed on the screw rod 6. The nut slider 5 is provided with a split groove 5b that penetrates the cross section of the internal threaded hole 5a. The split groove 5b divides the internal threaded hole of the nut slider 5 into two parts, front and rear, along the axial direction. The nut slider 5 is provided with an adjustment screw 11 that connects the front and rear end surfaces of the split groove 5b. The adjustment screw 11 is located above the internal threaded hole 5a. The width of the split groove 5b along the axial direction is adjusted by rotating the adjustment screw 11 to eliminate the matching clearance between the screw rod 6 and the nut slider 5, thereby ensuring the transmission accuracy of the screw rod.

[0028] As a preferred solution, the nut slider 5 is further provided with two positioning screws 12 above the internal threaded hole 5a, and the two positioning screws 12 are symmetrically arranged on both sides below the adjusting screw 11. The positioning screws 12 pass through the split groove 5b from the outside to the inside and press against the end surface inside the split groove 5b. The positioning screws 12 cooperate with the adjusting screws 11 to prevent the width of the split groove 5b from changing slightly during the rotation of the screw rod 6, thereby further improving the transmission accuracy of the screw rod.

[0029] The nut slider 5 is also provided with guide post holes 5c located on both sides of the internal threaded hole 5a, and the axes of the two guide post holes 5c are at the same height as the axis of the internal threaded hole 5a. The guide post 4 is installed in the corresponding guide post hole 5c, and the guide post 4 and the guide post hole 5c are in a sliding fit to limit all degrees of freedom of the slider nut except for the axial movement of the guide post. Figure 5 and Figure 6 One end of the guide column 4 is matched with one of the bearing seats by the shaft hole, and then locked by the set screw 14 installed on the top of the bearing seat. The other end of the guide column 4 is connected to the other bearing seat by the screw 13, and the screw 13 is screwed into the end of the guide column 4 from the top in the horizontal direction. The parallelism of the two guide columns 4 in the entire travel range can be fine-tuned by connecting the screw 13 to one end of the guide column to ensure the parallelism of the guide columns in the entire travel range.

[0030] The regulation process of the present invention is as follows:

[0031] When the clearance between the nut slider 5 and the screw rod 6 is too large, first loosen the positioning screw 12 counterclockwise, and then tighten the adjustment screw 11 clockwise. At this time, the width of the split groove 5b on the nut slider is reduced, thereby eliminating the clearance between the nut slider 5 and the screw rod 6, and then tighten the positioning screw 12 to fix the size of the split groove. When the clearance between the nut slider 5 and the screw rod 6 is too small, the tension of the adjustment screw 11 presses the nut slider 5 and the screw rod 6 too tightly, making it difficult for the screw rod to rotate. You can first slightly loosen the adjustment screw 11 and then tighten the positioning screw 12 clockwise to make the split groove 5b produce a slight deformation to unload part of the pressure until the motion damping between the nut slider 5 and the screw rod 6 is appropriate.

[0032] Combination Figure 7 As shown in the figure, when the torque required for the nut slider 5 to rotate the screw rod at both ends of the guide column is different, first loosen the screws on the front and rear end bearing seats 2 and turn the slider nut 5 to Figure 7 Position as shown, then tighten the set screw 14 on the rear end bearing seat 3, and then tighten the screw 13 in front of the front end bearing seat 2, so that the parallelism of the guide column can be adjusted.

[0033] The above is only a description of the preferred embodiment of the present invention, and is not intended to limit the scope of protection of the present invention. Obviously, any technician familiar with the field can easily think of replacements or changes to obtain other embodiments based on the above embodiments, which should all be included in the scope of protection of the present invention.

Claims

1. A screw transmission device in a sinusoidal mechanism, characterized in that: It includes a fixed seat, two bearing seats respectively installed at the front and rear ends of the fixed seat, two guide pillars, a nut slider and a screw rod. The two ends of the screw rod are respectively mounted on two bearing seats through bearings, the nut slider is screwed on the screw rod, the nut slider is provided with a split groove penetrating the cross section of the internal threaded hole, the nut slider is provided with an adjusting screw connecting the front and rear end surfaces of the split groove, and the adjusting screw is located above the internal threaded hole. The nut slider is also provided with guide post holes located on both sides of the internal threaded hole. The guide posts are installed in the corresponding guide post holes. The guide posts and the guide post holes are slidably matched. One end of the guide post is matched with the shaft hole of one of the bearing seats and then locked by a set screw installed on the top of the bearing seat. The end face of the other end of the guide post is connected with a screw horizontally installed on the other bearing seat. The nut slider is also equipped with two positioning screws above the internal threaded hole. The two positioning screws are symmetrically arranged on both sides below the adjusting screw. The positioning screws pass through the split groove from the outside to the inside and press on the end surface inside the split groove.

2. The screw transmission device in the sine mechanism according to claim 1, characterized in that: The axes of the two guide post holes are at the same height as the axis of the internal threaded hole.

3. The screw transmission device in the sine mechanism according to claim 1, characterized in that: The two ends of the bearing seat are mounted on the fixing seat through fixing screws, flat washers and elastic washers.

4. The screw transmission device in the sine mechanism according to claim 1, characterized in that: The shape of the nut slider is T-shaped.

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