A gear generation instrument with a symmetric structure

Abstract

The present invention relates to a generating instrument, specifically to a gear generating instrument with a symmetrical structure, which includes a base, supports, a screw rod, a disk gear, a rack and a cutter; the disk gear is connected to the center of the base through a rotating shaft at the center of the circle, and a round pin for positioning a gear blank on the disk gear is provided at the center of the top end face of the rotating shaft; a pair of supports are symmetrically arranged with respect to the disk gear, and the supports are slidably arranged on the base; the screw rod passes through the supports in sequence, and the screw rod is threadedly connected to the supports, and rotating the screw rod makes the supports slide towards or away from each other; there are a pair of racks, which are respectively slidably arranged on the supports, and the teeth of the racks are in a meshing structure with the teeth of the disk gear; there are a pair of cutters, which are respectively arranged on the racks. Compared with the prior art, the present invention solves the defects in the prior art such as large friction transmission error between the cutter of the gear generating instrument and the gear to be cut, only being able to draw partial tooth profile lines, and small applicable range of gear parameters.

Description

Technical Field

[0001] The present invention relates to a generating instrument, and more particularly to a gear generating instrument with a symmetric structure. Background Art

[0002] A gear generating instrument is a teaching aid for demonstrating the principle of manufacturing involute gears by the generation method. Through gear generation experiments, students can more intuitively and specifically understand the machining process of involute gear tooth profiles, and at the same time better understand the reasons for gear undercutting and the method of avoiding undercutting by profile modification.

[0003] However, there are some problems with existing gear generating instruments. For example, in the Chinese utility model patent with the publication number CN 204740794 U, the relative movement between the tool and the gear to be cut is achieved by friction drive. However, after using this structure for a period of time, pure rolling cannot be guaranteed, and it becomes a state with both rolling and sliding, which is likely to cause distortion of the involute tooth profile curve of the gear. In other generating instruments, such as the existing generating instrument composed of a tray, a base, a rack cutter, and a carriage, only part of the gear tooth profile line can be drawn, which is not vivid enough and cannot intuitively show the basic principle of gear machining by the generation method. It is necessary to repeatedly adjust the position of the circular paper in the experiment, resulting in a large error. And for large gear generating instruments composed of gear mechanisms, cam mechanisms, etc., the composition is relatively complex, the operation is not easy, and the cost is relatively high.

[0004] Therefore, in order to demonstrate more conveniently and accurately, a generating instrument with a simple structure and long-term usability needs to be proposed. Summary of the Invention

[0005] The purpose of the present invention is to provide a gear generating instrument with a symmetric structure to solve at least one of the above problems, so as to solve the defects in the prior art such as large friction drive error between the tool and the gear to be cut of the gear generating instrument, only being able to draw part of the tooth profile line, and small applicable range of gear parameters. It realizes the simultaneous drawing of the full tooth profile line, improves the experimental efficiency, and can draw gear contour lines in different ranges by replacing the gear disc.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A gear generating instrument with a symmetric structure includes a base, a support, a screw, a disc gear, a rack, and a cutter;

[0008] The disc gear is connected to the center of the base through a rotating shaft at the center of the circle, and a round needle for positioning the gear blank on the disc gear is provided at the center of the top end face of the rotating shaft;

[0009] A pair of supports are symmetrically arranged with respect to the disc gear, and the supports are slidably arranged on the base;

[0010] The described screw rod passes through the support in sequence, and the screw rod is threadedly connected to the support. Rotating the screw rod makes the supports slide towards or away from each other;

[0011] There are a pair of the described racks, which are respectively slidably arranged on the supports. The teeth of the rack are in a meshing structure with the teeth of the disc gear;

[0012] There are a pair of the described cutters, which are respectively arranged on the racks.

[0013] Preferably, one end of the screw rod is connected with a handle.

[0014] Preferably, the base is provided with an opening through which the screw rod passes to limit the movement of the screw rod.

[0015] Preferably, the rotation direction between the disc gear and the rotating shaft is restricted by a one-way bearing.

[0016] Preferably, a pressing plate is connected to the top end of the rotating shaft, and the pressing plate presses the gear paper blank onto the disc gear.

[0017] Preferably, a number of fixing holes are correspondingly arranged on the pressing plate and the disc gear.

[0018] Preferably, the support is provided with a groove perpendicular to the screw rod, and the rack is provided with a convex block, and the convex block is slidably arranged in the groove.

[0019] Preferably, the support is provided with scales along the sliding direction of the rack.

[0020] Preferably, the rack is provided with a stud, and the cutter is provided with a chute parallel to the screw rod. After passing the stud through the chute and adjusting the position of the cutter, the cutter is locked on the rack by a compression nut.

[0021] Preferably, the rack is provided with scales along the sliding direction of the cutter.

[0022] The working principle of the present invention is as follows:

[0023] According to the target standard gear parameters, select the cutters and disc gears with corresponding appropriate sizes and install them on the racks and the base correspondingly. Calculate and draw parameters such as the pitch circle, root circle, addendum circle and the addendum circle diameter of the positively modified gear on the drawing, cut off the redundant paper to obtain the gear paper blank, and position the gear paper blank on the disc gear through a round needle.

[0024] First, push the rack to the extreme position at one end, and rotate the screw rod so that the supports on both sides and the rack move towards the middle disk gear simultaneously and complete the meshing of the rack and the disk gear. Adjust the center line of the tool so that it is tangent to the pitch circle of the gear to be machined. Trace the tooth profile of the tool on the gear paper blank (equivalent to the tool mark left after one cutting at this position), then push the rack back a very small distance (about 2 mm). At this time, the gear paper blank on the disk gear rotates through a certain angle, and the tool profile is traced again. Repeat the steps of pushing back - tracing the edge.

[0025] If the number of teeth and the module are within the compliant range, the drawing of the entire tooth profile can be completed; if it exceeds the range, it is necessary to replace the appropriate disk gear or repeat until only 2 - 3 complete teeth are drawn.

[0026] Remove the gear paper blank and mark the base circle, pitch circle, addendum circle and their diameters.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. In the present invention, the racks on both sides are meshed with the disk gear by synchronously moving through the screw rod to achieve synchronous rotation, and the contour lines can be drawn simultaneously on both sides of the disk gear, observing the undercut phenomenon of the involute gear, improving the experimental efficiency, and realizing the drawing of the entire gear contour line. Moreover, the complete meshing of the rack and the disk gear can ensure that there is only pure rolling during the movement, overcoming the problems existing in the prior art.

[0029] 2. The tool of the present invention can move back and forth on the rack to complete the drawing of the contour line of the modified gear and the study of the law.

[0030] 3. The disk gear of the present invention can, while ensuring that the module remains unchanged, change the number of teeth according to the parameters of the standard gear to be drawn, change the center distance, and thus realize the drawing of the standard gear contour line in a larger range. Brief Description of the Drawings

[0031] Figure 1 It is a schematic structural diagram of a gear generating instrument with a symmetrical structure;

[0032] Figure 2 It is a schematic structural diagram of the gear generating instrument with a symmetrical structure after removing the tool;

[0033] Figure 3 It is a schematic front view structural diagram of the gear generating instrument with a symmetrical structure;

[0034] In the figure: 1 - base; 2 - support; 3 - handle; 4 - screw rod; 5 - compression nut; 6 - disk gear; 7 - pressing plate; 8 - rack; 9 - tool; 10 - one - way bearing; 11 - fixing hole. Detailed Embodiment

[0035] The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0036] Embodiment 1

[0037] A gear generating instrument with a symmetrical structure, as Figures 1 - 3 shown, includes a base 1, supports 2, a handle 3, a screw 4, a compression nut 5, a disk gear 6, a pressing plate 7, a rack 8, a cutter 9, a one-way bearing 10, and a fixing hole 11;

[0038] The disk gear 6 is connected to the center of the base 1 through a rotating shaft at the center of the circle, and a round pin for positioning the gear blank on the disk gear 6 is provided at the center of the top end face of the rotating shaft;

[0039] A pair of supports 2 are symmetrically arranged with respect to the disk gear 6, and the supports 2 are slidably arranged on the base 1;

[0040] The screw 4 passes through the supports 2 in sequence, and the screw 4 is threadedly connected to the supports 2. Rotating the screw 4 causes the supports 2 to slide towards or away from each other;

[0041] A pair of the racks 8 are respectively slidably arranged on the supports 2, and the teeth of the racks 8 and the teeth of the disk gear 6 are in a meshing structure;

[0042] A pair of the cutters 9 are respectively arranged on the racks 8, and the compression nut 5 is threadedly connected to the stud on the rack 8 to fix the cutter 9 on the rack 8.

[0043] More specifically, in this embodiment:

[0044] The gear generating instrument includes a base 1 and supports 2, a screw 4, and a disk gear 6 installed on the base 1. Among them, the disk gear 6 is located at the center of the base 1, the supports 2 are symmetrically arranged on both sides of the disk gear 6, and the screw 4 passes through the supports 2 on both sides in sequence and is threadedly connected to the supports 2. Combining Figures 1 - 3 It can be seen that the base 1 is arranged in an inverted T shape, and the groove provided on the bottom surface of the support 2 forms a sliding connection with the top surface of the convex part on the base 1, so that the support 2 can move Figure 1 in the horizontal direction as shown; correspondingly, the screw 4 is a double-headed screw 4 and the threads at both ends of the screw 4 are arranged in the opposite direction, so that when the screw 4 is rotated, the supports 2 on both sides can move synchronously towards or away from each other (synchronously approaching or moving away from the disk gear 6).

[0045] A handle 3 is installed at one end of the screw 4, and it can be connected in a detachable form such as threaded connection, key connection, etc., or it can also be in an integrally formed structure or a fixed connection method such as welding. Corresponding openings are provided at the positions where the screw 4 extends into / extends out of the support 2, which can limit the translational movement of the screw 4 in the plane after the screw 4 is assembled.

[0046] The disk gear 6 is connected to the center of the base 1 through a rotating shaft at the center. A one-way bearing 10 is further provided between the disk gear 6 and the rotating shaft to limit the rotation to one-way rotation. At the top end of the rotating shaft, i.e., the end close to the disk gear 6, a round pin is provided at the center to position the gear paper blank placed on the disk gear 6. Further, a pressing plate 7 is sleeved outside the rotating shaft and presses the gear paper blank onto the disk gear 6. Three fixing holes 11 with an included angle of 120° with each other are respectively provided on the pressing plate 7 and the disk gear 6. By passing through the corresponding fixing holes 11 with fixing pins, drawing pins, etc., the pressing plate 7, the disk gear 6 and the gear paper blank form an integral whole and perform synchronous movement.

[0047] A groove is provided on the support 2 on both sides of the disk gear 6 perpendicular to the screw 4. A clamping block is connected to the lower surface of the rack 8 (the width of the clamping block matches the groove and the length of the clamping block is less than the length of the groove). By placing the clamping block in the groove, the rack 8 can slide along the groove, i.e., in the direction perpendicular to the screw 4. The side part of the support 2 not blocked by the rack 8 is marked with a scale in the same direction as the sliding direction of the rack 8, which is convenient for accurately adjusting the movement distance of the rack 8 during the test. The teeth of the rack 8 are engaged with the tooth pattern of the disk gear 6. After the racks 8 on both sides are adjusted to be close to the disk gear 6 by the screw 4, the rack 8 and the disk gear 6 are engaged, and the disk gear 6 is driven to rotate by sliding the rack 8.

[0048] A stud is provided on the upper surface of the rack 8. A sliding groove is correspondingly provided on the cutter 9 along the direction parallel to the screw 4. After aligning the sliding groove with the stud and adjusting the cutter 9 to be close to / away from the disk gear 6 to a suitable position, the cutter 9 is fixed on the rack 8 by tightening the compression nut 5. The side of the rack 8 not blocked by the cutter 9 is marked with a scale in the same direction as the sliding direction of the cutter 9, which is convenient for measuring the corresponding addendum modification amount after the cutter 9 is adjusted. The cutter 9 is made of acrylic plate and is located above the gear paper blank.

[0049] When the gear generating instrument works, according to the target standard gear parameters, select the appropriate cutter 9 and disk gear 6 and complete the installation of the gear generating instrument. Calculate and draw the pitch circle, root circle, addendum circle and the addendum circle diameter of the positively modified gear on the drawing, cut off the redundant paper to obtain the gear paper blank, and fix it on the disk gear 6 with the pressing plate 7 and drawing pins.

[0050] First, push the rack 8 to the extreme position at one end, and turn the handle 3 to rotate the screw 4 so that the supports 2 on both sides and the rack 8 move towards the middle disk gear 6 simultaneously and engage. Adjust the center line of the tool 9 so that it is tangent to the pitch circle of the gear to be machined. Use a sharp pencil to trace the tooth profile of the tool 9 on the gear paper blank at this time, which is equivalent to the tool mark left after the tool 9 cuts once at this position. Then, push the rack 8 and the tool 9 a very small distance towards the other end (cooperate with the scale to control the moving distance about 2 mm). At this time, the gear paper blank pressed on the disk gear 6 will rotate through a certain angle, and use a pencil to trace the contour of the tool 9 after moving. Repeat the above steps to trace the tooth profiles of the tool 9 at various positions.

[0051] If the number of teeth and the module are within the compliant range, the drawing of the full tooth profile can be completed; if it exceeds the range, it is necessary to consider replacing the disk gear 6 or repeat until only 2 - 3 complete teeth are drawn.

[0052] Remove the gear paper blank, and mark the base circle, pitch circle, addendum circle and their diameters on it.

[0053] If it exceeds the full tooth profile range applicable to the existing disk gear 6, when replacing the disk gear 6, it is necessary to first turn the handle 3 to move the supports 2 on both sides away from the disk gear 6 and leave a certain amount of free space, replace the gear with a suitable diameter but the same module as the rack 8, install it on the one - way bearing 10, and then the test can be restarted; if the tool 9 needs to be replaced, just loosen the compression nut 5 and then replace it.

[0054] When drawing a modified gear, screw the paper blank of the modified gear into the working position, loosen the compression nut 5, adjust the center line of the tool 9, move it back and forth to the required modification amount, and then tighten the compression nut 5 so that it is separated from or intersects with the pitch circle of the gear to be machined. The tool 9 moving closer to the disk gear 6 is the negative modification cutting position, and moving away from the disk gear 6 is the positive modification cutting position. The moving amount of the tool 9 is equal to the modification amount, that is, the modification coefficient multiplied by the module, which can be read from the scale marked on the rack 8.

[0055] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. Those skilled in the art can obviously make various modifications to these embodiments easily and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention according to the disclosure of the present invention should be within the protection scope of the present invention.

Claims

1. A gear generation instrument with a symmetric structure, characterized in that, It includes a base (1), a support (2), a screw rod (4), a disk gear (6), a rack (8) and a cutter (9); The disk gear (6) is connected to the center of the base (1) through a rotating shaft at the center of the circle, and a round needle for positioning the gear blank on the disk gear (6) is provided at the center of the end face of the top of the rotating shaft; A pair of supports (2) are symmetrically arranged with respect to the disk gear (6), and the supports (2) are slidably arranged on the base (1); The screw rod (4) sequentially passes through the supports (2), and the screw rod (4) is threadedly connected to the supports (2). Rotating the screw rod (4) causes the supports (2) to slide towards or away from each other; A pair of racks (8) are provided, which are respectively slidably arranged on the supports (2), and the teeth of the racks (8) are in a meshing structure with the teeth of the disk gear (6); A pair of cutters (9) are provided, which are respectively arranged on the racks (8).

2. A gear generation instrument with a symmetric structure according to claim 1, characterized in that, One end of the screw rod (4) is connected with a handle (3).

3. The gear generation instrument with a symmetrical structure according to claim 1, characterized in that, The base (1) is provided with an opening through which the screw rod (4) passes, restricting the movement of the screw rod (4).

4. A gear generating instrument with a symmetrical structure according to claim 1, characterized in that The rotation direction between the disk gear (6) and the rotating shaft is restricted by a one-way bearing (10).

5. A gear generation instrument with a symmetrical structure according to claim 1, characterized in that, The top end of the rotating shaft is connected with a pressing plate (7), and the pressing plate (7) presses the gear blank against the disk gear (6).

6. A gear generation instrument with a symmetrical structure according to claim 5, characterized in that, A number of fixing holes (11) are correspondingly provided on the pressing plate (7) and the disk gear (6).

7. A gear generating instrument with a symmetrical structure according to claim 1, characterized in that, The support (2) is provided with a groove perpendicular to the screw rod (4), and the rack (8) is provided with a convex block, and the convex block is slidably arranged in the groove.

8. A gear generation instrument with a symmetric structure according to claim 7, characterized in that, The support (2) is provided with a scale along the sliding direction of the rack (8).

9. A gear generating instrument with a symmetric structure according to claim 1, characterized in that, The rack (8) is provided with a stud, and the cutter (9) is provided with a chute parallel to the screw rod (4). After passing the stud through the chute and adjusting the position of the cutter (9), the cutter (9) is locked to the rack (8) by a compression nut (5).

10. A gear generation instrument with a symmetrical structure according to claim 9, characterized in that, The rack (8) is provided with a scale along the sliding direction of the cutter (9).

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