KR101518413B1 - Gear Assembly for Back-lash Elimination and Main Spindle Driving Apparatus of Hobbing Machine Using Thereof - Google Patents

Abstract

The present invention relates to a gear assembly for back-lash elimination, which provides a great effect of the back-lash elimination in a gear mechanism which generates a big resistance intermittently with regard to a driving direction, and is superior in manufacturing and assembling properties along with an increase of a minimum size, and relates to a main spindle driving apparatus of a hobbing machine, which is capable of improving a gear polishing density by effectively eliminating a back-lash of the spindle driving apparatus for operating a hob cuter by applying the gear assembly for the back-lash elimination. The gear assembly for the back-lash elimination is comprised of: a main gear (110) which interlocks with a drive gear; a sub-gear (120) for the back-lash elimination which is coupled to one side in the axial direction of the main gear to allow sliding and rotation and interlocks with the drive gear along with the main gear; a fixing plate (130) integrally coupled to the main gear while blocking the outer surface of the sub-gear (120) for the back-lash elimination, in a sliding state; an annular groove (116) of a cross-section square, formed on the adhering surface of the main gear and the sub-gear for the back-lash elimination; and an elastic ring (140) installed to slide in the annular groove by including an annular elastic body of a cross-section square, in which a portion of the circumference is eliminated to fix one end in the sub-gear for the back-lash elimination, and fix the other end in the main gear. The elastic ring generates a pre-load in the direction of supplying an elastic restoring force for squashing the conical surface of the follow-up side of the drive gear by rotating the sub-gear for the back-lash elimination in the direction of transmitting driving power.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a backlash-removing gear assembly and a hobbing machine using the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for removing a backlash between gears that engage with each other, and more particularly, to a gear mechanism in which a large resistance is intermittently generated in a driving direction, A backlash removing gear assembly excellent in performance and assembling ability and a spindle driving device of a hobbing machine capable of improving gear cutting precision by effectively removing the backlash of the main spindle driving device that drives the hob cutter by applying the backlash removing gear assembly .

A CNC hobbing machine is typically used to machine gears. In the CNC hobbing machine, a gear device is used for the power transmission system of the main shaft for rotationally driving the hob cutter.

2. Description of the Related Art Generally, a gear device is widely used for high durability and smooth power transmission characteristics because two gears are meshed with each other to smoothly transmit rotational power. However, a backlash must be indispensable for the teeth of the two meshing gears to rotate smoothly. This backlash affects the rotation of the main spindle of the hobbing machine and the precision of gear processing.

Since the precision of the CNC hobbing machine itself is important to precisely process the gear, it is advantageous to set the gear backlash as small as possible in order to prevent the synchronization error of the shaft due to the gear backlash. In this case, Noise and vibration are generated.

Particularly, in the hobbing machine, since the hob cutter has to cut and cut the gear material by rotating the cutter blades of the same shape as the gear, when the cutter blade performs the cutting, Resistance occurs. However, since the cutter blades of the hob cutter rotate in the circumferential direction, the cutting depth is small at first, and the cutting depth is greatest when the cutter blade is positioned horizontally, so that the resistance continues to change. Further, since the cutter blades of the hob cutter are divided into several parts in the circumferential direction, the cutter blade and the cutter blade perform cutting with a time difference, so that a very high resistance section and a very small section are generated. That is, a large resistance force occurs intermittently.

When such a large resistance force is generated intermittently, a phenomenon repeatedly occurs when a force is applied to the gear train of the main shaft driving device for rotating the hob, and this causes vibration due to backlash between the meshing gears. Adverse effects.

In order to solve this problem, a belt having a simple structure and no backlash is used instead of a gear. However, unlike the theory, backlash occurs due to belt tension, which affects the processing accuracy.

On the other hand, various conventional examples for removing the backlash between the meshing gears are disclosed in Patent Documents 1 to 7.

Conventionally known techniques, including the techniques disclosed in Patent Documents 1 to 7, mainly focus on removing the backlash by rotating the backlash removing gear in the direction of the gap by a pressing mechanism such as a coil spring, a torsion spring, or a latch However, it is difficult to apply the present invention to a gear device in which a rotational force is so weak that it is restricted to a use place such as an optical pickup device such as a CD or a DVD and a large resistance force acts intermittently in one direction, such as a main axis of a hobbing machine.

In addition, a rectangular hole or groove should be formed in the disc-shaped gear for providing a pressurizing mechanism, but its structure is very complicated. In particular, since a square hole is impossible or extremely difficult to cut, It is hardly applicable to a gear made of a thick steel material (nickel-chrome steel, chrome-molybdenum steel or the like) like a spindle drive mechanism and is mainly applied to a plastic gear which can be formed by a press-formable thin metal plate material or by injection.

In addition, the conventional backlash eliminating gear is required to apply a preload to the pressurizing mechanism by rotating the backlash eliminating gear relative to the transmission gear before assembling with the counter gear. In this case, the backlash elimination gear There is a disadvantage that it is difficult to assemble and takes a long time because the means for holding the gear is not provided separately.

In addition, there is an example in which a C-type spring or a torsion spring is used as a conventional backlash removing gear. Since axial displacement is involved during spring operation, axial shaking occurs between the backlash removing gear and the transmission gear It is difficult to support the backlash elimination gear and the transmission gear with a minimum clearance so as not to move in the axial direction.

Patent Registration No. 10-1036747 Patent Registration No. 10-0420317 Patent Registration No. 10-0199391 Published Patent Publication No. 10-2007-0045478 Published Patent Publication No. 10-2007-0007464 Japanese Patent Application Laid-Open No. 2004-3593

SUMMARY OF THE INVENTION It is an object of the present invention to provide a gear mechanism in which a large resistance is intermittently applied to a driving direction and has a large backlash removing effect and a simple structure and an increase in size A backlash eliminating gear assembly which is structurally stable with less axial flow of the backlash elimination gear and which is excellent in manufacturability and assemblability and a spindle drive device which drives the hob cutter by applying such a backlash elimination gear assembly And it is an object of the present invention to provide a main spindle drive apparatus for a hobbing machine capable of effectively removing backlashes and improving structural stability by improving gear processing accuracy.

In order to achieve the above object, the backlash-removing gear assembly according to the present invention is characterized in that the backlash-removing gear assembly includes a driving force transmitting direction that receives a resistance force from an operating end of the gear transmission system, A main gear engaged with a drive gear driven in a simple rotation direction; A backlash removing sub gear having the same number and tooth profile as the main gear and slidably coupled to one axial side of the main gear to engage with the drive gear together with the main gear; A fixed plate integrally coupled to the main gear while blocking the outer surface of the backlash removing sub gear in a slidable state; An annular groove having a square cross section formed on the contact surface of the main gear and the backlash removing sub gear; And a fixing hole is formed at both ends in the circumferential direction so that one of the fixing holes is fastened from the backlash removing sub gear, And the opposite fixing hole includes an elastic ring to which a fixing bolt fastened from the main gear is inserted and fixed to the main gear; The direction of the preload applied to the elastic ring is set to a direction for rotating the backlash removing sub gear in the driving force transmitting direction to provide an elastic restoring force to be pressed against the follower tooth surface of the drive gear; Wherein the drive gear, the main gear, and the sub gear for removing the backlash are made of helical gears, and the torsional direction and the driving force transmission direction of the helical gear are set such that the backlash removing sub- And is configured so as to receive a thrust force which is slid in the axial direction and brought into close contact with the main gear by the twist angle of the follower tooth surface of the drive gear when elastically brought into close contact with the follower tooth surface of the drive gear.

In the backlash eliminating gear assembly according to the present invention, a temporary fixing screw hole is formed in the fixing plate so as to face the outer side surface of the backlash removing sub gear, and the temporary fixing screw hole The auxiliary gear is temporarily fixed to prevent the backlash removing sub gear from rotating with respect to the main gear in a state in which the outer ring of the sub gear is pressed in the axial direction and pressed against the side surface of the main gear, A fixing detent screw is fastened.

In the backlash removing gear assembly according to the present invention, a plurality of arcuate guide grooves are formed in the fixing plate, and a guide shaft passing through the arcuate guide grooves of the stationary plate is fastened to the backlash removing sub gear The rotational range of the backlash removing sub gear with respect to the main gear and the fixed plate is limited and the rotation is guided.

In the backlash-removing gear assembly according to the present invention, the annular groove of the square cross-section is formed to be recessed at a certain depth from the inner surface of the backlash-removing subgear; In the ring-shaped elastic ring of the square cross section, both side surfaces of the annular groove are in sliding contact with one side of the main gear and the inner surface of the annular groove.

A main spindle driving apparatus for a hobbing machine according to the present invention is a main spindle driving apparatus for a hobbing machine for driving a hob cutter (40) provided at an operative end of a power transmission system for cutting a gear, , A first drive gear (12) driven in a driving force transmitting direction that receives a resistance force from the cutting operation of the hob cutter (40) at an operating end and a simple rotating direction that simply rotates in the opposite direction without being subjected to a resistance force, A first shaft (10) having a drive gear (12); A second shaft 20 disposed in parallel with the first shaft 10; A first backlash removing gear assembly (100) according to any one of claims 1 to 4, which is installed on a second shaft (20) and engages with the first drive gear (12) to receive rotational power. A second drive gear (22) provided on the second shaft (20) together with the first backlash removing gear assembly (100); A third shaft 30 disposed in parallel to the second shaft 20 and having the hob cutter 40 mounted at one end thereof; And a second backlash removing gear assembly (500) according to any one of claims 1 to 4, which is mounted on the third shaft (30) and engaged with the second drive gear (22) to receive rotational power .

In the spindle drive apparatus for a hobbing machine according to the present invention, the helical twisting direction of the first gear pair composed of the first drive gear (12) and the first backlash elimination gear assembly (100) 22 and the second backlash eliminating gear assembly 500 are opposite to each other in the helical twisting direction.

According to the backlash removing gear assembly and the main shaft driving apparatus for a hobbing machine using the same according to the present invention, when the drive gear rotates in the driving force transmitting direction and backlash occurs between the follower tooth surface of the drive gear and the leading tooth surface of the main gear , The backlash removing sub gear is further pushed in the driving force transmitting direction which is the same direction as the drive gear and the back side lash is removed by pressing the front side of the drive gear against the side of the follower face of the drive gear. Therefore, the resistance force acting intermittently in the direction opposite to the driving force transmitting direction and the shaking caused thereby can be effectively removed by the backlash removing gear assembly, and the driving stability can be ensured.

Further, by utilizing the resilient restoring force of the elastic ring of the square cross-section, it is easy to elastically press the backlash removing sub gear in one direction of the driving force transmission, and at the same time, the flat both surfaces of the square cross- , The elastic ring is constrained so as to minimize the axial flow in the annular groove so that axial torsion can be minimized when the elastic ring contracts or expands in the radial direction and stable operation becomes possible, Can be minimized.

Further, since the backlash removing sub gear can be fixed to the main gear by the temporarily fixing detent screw in the state where the elastic ring is preloaded, the backlash removing gear assembly can be easily engaged with the drive gear and assembled, The elastic restoring force of the elastic ring acts directly on the sub gear for removing the backlash.

In addition, the drive gear, the main gear, and the sub gear for removing the backlash are constituted by helical gears, and the torsional direction of the helical gear and the driving force transmission direction are controlled by the elastic restoring force of the elastic ring, Gears for backlash removal are arranged so as to receive a thrust force that is slid in the axial direction and brought into close contact with the main gear due to the twist angle of the follower tooth surface of the drive gear when elastically brought into close contact with the follower tooth surface of the gear, So that the driving can be stably performed. Accordingly, it is possible to process the gear with high precision.

In addition, the rotational force transmitted to the hob cutter can be maximized by connecting three axes from the drive source to the hob cutter and decelerating in two steps.

In addition, by constituting the driven gear that receives the rotational power to the drive gear with the backlash removing gear assembly according to the present invention, even if large resistance force is generated intermittently and repeatedly from the hob cutter at the time of gear cutting, So that excellent gear machining precision can be ensured.

1 is a view showing a main spindle driving apparatus of a hobbing machine according to the present invention.
Fig. 2 is a view as seen from the right side of Fig.
3 is a perspective view showing the drive relationship of the backlash-removing gear assemblies according to the present invention.
4A is a side view of a backlash removal gear assembly (first backlash removal gear assembly) in accordance with the present invention.
4B is a cross-sectional view taken along line AA of FIG. 4A.
4C is a sectional view taken along line BB in Fig. 4A. Fig.
Fig. 5 is an essential detail view for explaining the backlash removing principle of the first backlash removing gear assembly. Fig.
6 is a view for explaining the driving force transmission direction and the arrangement relationship of the first backlash elimination gear assembly.
7A is a side view of a second backlash elimination gear assembly in accordance with the present invention.
FIG. 7B is a cross-sectional view taken along line CC of FIG. 7A. FIG.
7C is a cross-sectional view taken along line DD of Fig. 7A.
Fig. 8 is an essential detail view for explaining the backlash removing principle of the second backlash removing gear assembly. Fig.
FIG. 9 is a graph comparing a tooth surface condition measurement graph of a gear machined in a hobbing machine to which a conventional drive device and a drive device using a backlash removing gear assembly according to the present invention are applied.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of a backlash removing gear assembly and a spindle driving device of a hobbing machine of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 and FIG. 2 show the overall structure of a main shaft driving apparatus of a hobbing machine according to the present invention. FIG. 1 shows an overall structure thereof, and FIG. 2 shows a right side view of FIG.

1 and 2, the main shaft driving device of the hobbing machine includes a gear device that transmits rotational power generated by the driving source 2, such as a motor, to the hob cutter 40, which is the operative end of the power transmission system.

In the present specification, the term "driving force transmission direction" is defined as a direction in which a gear is cut in a hob cutter 40 that is an operative end, and a "simple rotation direction" is defined as a direction in which gear cutting is not performed, .

Therefore, when the hob cutter 40 rotates in the driving force transmitting direction and cuts the workpiece, the resistance force received by the hob cutter 40 is transmitted to the driving source 2 via the gear power transmission device upside down, It is possible to use a motor having a rotational force capable of overcoming the resistance.

The main shaft driving device of the hobbing machine includes a first shaft 10 connected to the driving source 2, a second shaft 20 which is an idle shaft receiving rotational power from the first shaft 10, And a third shaft 30 which is a spindle shaft on which the hob cutter 40 is mounted while being subjected to rotational power.

The gear mechanism increases the torque of the hob cutter 40 by decelerating the power of the drive source 2 from the first axis 10 to the third axis 30 in two steps.

The gear mechanism is provided with a first drive gear 12 on the first shaft 10 and a second drive gear 22 on the second shaft 20 in accordance with the present invention. And a third shaft 30 is provided with a second backlash removing gear assembly 500 according to the present invention.

That is, by connecting the three shafts 10, 20, 30 from the drive source 2 to the hob cutter 40, and decelerating in two steps, the rotational force transmitted to the hob cutter 40 is maximized. In addition, by constituting the driven gear that receives the rotational power to the drive gears 12 and 22 with the backlash removing gear assemblies 100 and 500, a large resistance force from the hob cutter 40 at the time of gear cutting is intermittent, The backlash in the opposite direction of the driving force transmission direction is removed to minimize the vibration, thereby ensuring excellent gear machining accuracy.

Here, the first backlash elimination gear assembly 100 and the second backlash elimination gear assembly 500 are distinguished by attaching 'first' and 'second' to the front of the name for convenience of explanation, (100, 500) are structurally identical except that they are different in size.

The first backlash elimination gear assembly 100 includes a first main gear 110 that is engaged with the first drive gear 12 and receives rotational power and a second main gear 110 that is rotated between the first drive gear 12 and the first main gear 110 A first backlash removing sub gear 120 for removing the backlash of the first backlash removing sub gear 120 and a first fixing plate for fixing the first backlash removing sub gear 120 to the first drive gear 12 in a slidable rotation state, (130).

Similarly, the second backlash elimination gear assembly 500 includes a second main gear 510 which is engaged with the second drive gear 22 to receive rotational power, a second main gear 510 which is coupled to the second drive gear 22 and the second main gear 510 A second backlash removing sub gear 520 for removing a backlash between the first backlash removing sub gear 520 and the second backlash removing sub gear 520 and a second fixing plate for fixing the second backlash removing sub gear 520 to the drive gear 22 in a slidable rotation state, (530).

FIG. 3 is a perspective view showing the drive relationship of the first and second backlash removing gear assemblies 100 and 500. FIG.

3, a first gear pair consisting of a first drive gear 12 and a first backlash elimination gear assembly 100 and a second gear pair consisting of a first drive gear 22 and a second backlash elimination gear assembly 500 The second gear pair is composed of a helical gear having a predetermined helix angle with respect to the axial direction, thereby increasing the engagement ratio and smoothly transmitting power, which is advantageous for precise gear cutting.

3, when the gear device rotates in the driving force transmitting direction, a tooth surface leading to the driving force transmission direction among the two tooth surfaces of a gear tooth (jaw) is referred to as a leading tooth surface, Quot ;, and the following tooth surface is set as a " trailing face ".

3, when the first drive gear 12 rotates in the driving force transmission direction (counterclockwise in FIG. 3), the leading tooth surface of the first drive gear 12 is in contact with the follower of the first main gear 110 A clearance, that is, a backlash is generated between the follower tooth surface of the first drive gear 12 and the leading tooth surface of the first main gear 110 by transmitting the rotational force. Accordingly, the first backlash removing sub gear 120 is further pushed in the driving force transmitting direction, which is the same direction as the first drive gear 12, so that the front side tooth surface thereof is in contact with the follower side tooth surface So that the backlash is removed.

Similarly, when the second drive gear 22 rotates in the driving force transmission direction (clockwise direction in FIG. 3), the leading tooth surface of the second drive gear 22 is in close contact with the follower tooth surface of the second main gear 510 That is, a backlash is generated between the follower tooth surface of the second drive gear 22 and the leading tooth surface of the second main gear 510. As a result, Thus, the second backlash removing sub gear 520 is further pushed in the driving force transmitting direction, which is the same direction as the second drive gear 22, so that its leading side tooth surface is in contact with the follower side tooth surface So that the backlash is removed.

4A to 4C show a detailed configuration of a first backlash removing gear assembly 100 according to the present invention, in which a side view is shown in FIG. 4A, and a cross-sectional view taken along the line AA in FIG. 4A is shown in FIG. 4B And FIG. 4C is a sectional view taken along the line BB of FIG. 4A. Hereinafter, description will be made with reference to FIG. 3 in parallel.

Referring to FIGS. 3 and 4A to 4C, the first backlash elimination gear assembly 100 includes a first main gear 110, a first backlash removing sub gear 120, (130) and a first elastic ring (140).

The first main gear 110 and the first backlash removing sub gear 120 are engaged with the first drive gear 12 with the same number and tooth shape.

The first main gear 110 is fixed to the first shaft 10 and rotates integrally with the first main gear 110. The first sub gear 120 for removing backlash is fixed to one axial side 112 of the first main gear 110 So as to be slidably rotatable.

The first fixing plate 130 is fixed to the first main gear 110 by a plurality of fixing bolts 150 while the outer side surface 126 of the first backlash removing sub gear 120 is slidably closed Respectively.

A first annular groove 116 having a rectangular cross section is formed on the contact surfaces 112 and 122 of the first main gear 110 and the first backlash removing sub gear 120 and the first annular groove 116 The first elastic ring 140 is provided in a slidable state.

In the embodiment shown in the drawing, the first annular groove 116 is formed to be recessed at a certain depth from the surface of the inner side surface 122 of the first backlash removing sub gear 120. The first resilient ring 140 having a square cross section is configured such that both sides thereof in the first annular groove 116 slide on the inner surface of the side 112 of the first main gear 110 and the inner surface of the first annular groove 116 . The first elastic ring 140 is made of a ring having a rectangular section and has flat sides on both sides and has flat side surfaces that slide on the inner surface of the side surface 112 of the first main gear 110 and the inner surface of the first annular groove 116 Thereby constraining the axial flow in the first annular groove 116 to be minimized so that axial torsion can be minimized when the first elastic ring 140 contracts or expands in the radial direction, The operation can be performed and the concentration of stress in one place can be minimized.

The first elastic ring 140 having such a square cross section is constituted by an annular elastic body in which a part of its circumference is removed as shown by a dotted line in Fig. 4A, and on both circumferential ends of the removed portion, As shown, fixing holes 142 and 144 are formed, respectively.

One fixing hole 142 of the first elastic ring 140 is inserted into the first backlash removing sub gear 120 by inserting the fixing bolt 160 fastened from the first backlash removing sub gear 120, And the opposite fixing hole 144 is fixed to the first main gear 110 by inserting a fixing bolt 170 fastened from the first main gear 110. [

Therefore, by rotating the first main gear 110 and the first backlash removing sub gear 120 in directions opposite to each other and radially expanding the first elastic ring 140, the first elastic ring 140 The first elastic ring 140 provides an elastic restoring force for returning the first main gear 110 and the first backlash removing sub gear 120 to the original position when a preliminary pressure is applied.

4A and 4C, the boss 114 extends from the side surface 112 of the first main gear 110 and the boss 114 is engaged with the first backlash removing sub gear 120, And is inserted into the central shaft hole 124 in the state of being slidable. The first fixed plate 130 is also configured with a flange 132 and a boss 134 so that the flange 132 can slide the outer surface 126 of the first backlash- And the boss 134 is inserted into the central shaft hole 124 of the first backlash removing sub gear 120 so as to be slidable. The fixing bolts 150 are fastened to the bosses 114 of the first main gear 110 and the bosses 134 of the first fixing plate 130 to be integrated.

The boss 114 of the first main gear 110 and the boss 134 of the first fixing plate 130 are inserted into the central shaft hole 124 of the first backlash removing sub gear 120, The outer surface 126 of the first backlash removing sub gear 120 is slidably engaged with the flange 132 of the first fixing plate 130 so that the outer surface 126 of the first backlash removing gear assembly 100 The axial thickness can be minimized and stable operation is possible.

4A and 4C, a flange 132 of the first fixing plate 130 is provided with a provisional fixing screw 130 which faces the outer side surface 126 of the first backlash removing sub gear 120, A hole 136 is formed. A provisional fixing detent screw 180 for pressing and fixing the outer surface 126 of the first backlash removing sub gear 120 in the axial direction is fastened to the temporary fixing screw hole 136.

The temporary fixing detent screw 180 is formed by pushing the first backlash removing sub gear 120 to the side of the first main gear 110 so that the first elastic ring 140 is preloaded And serves to temporarily fix the first backlash removing sub gear 120 to prevent rotation with respect to the first main gear 110. The temporarily fixing detent screw 180 is temporarily provided for the convenience of assembly and is removed after assembly.

That is, when the first backlash removing sub gear 120 is rotated in the opposite direction to the driving force transmitting direction with respect to the first main gear 110, an elastic restoring force for returning to the driving force transmitting direction is applied to the first elastic ring 140, , A preload is applied. Since the first backlash removing sub gear 120 is fixed to the first main gear 110 in a state where a preload is applied to the first elastic ring 140 as described above, So that the backlash-removing gear assembly 100 can be easily assembled when engaged with the first drive gear 12. When the temporary fixing detent screw 180 is removed after the assembly is completed, an elastic restoring force of the first elastic ring 140 acts to rotate the first backlash removing sub gear 120 in the driving force transmitting direction, The front side tooth surface of the first backlash removing sub gear 120 is brought into close contact with the follower tooth surface of the first drive gear 12 and pressed to remove the backlash.

4A and 4C, a plurality of arc-shaped guide grooves 138 are formed in the first fixed plate 130, and the arc-shaped guide grooves 138 are formed in the first backlash removing sub gear 120, And a guide shaft 139 passing through the guide groove 138 is screwed and fixed. Accordingly, the rotation range of the first backlash removing sub gear 120 with respect to the first main gear 110 and the first fixing plate 130 is changed in such a manner that the guide shaft 139 rotates in the arc- While its rotation is guided.

5, there is shown a principal detail view for explaining the backlash removal principle of the first backlash-removing gear assembly 100. As shown in FIG.

The first backlash removing sub gear 120 is moved in the direction opposite to the driving force transmitting direction with respect to the first main gear 110 before the first backlash removing gear assembly 100 is engaged and engaged with the first drive gear 12 And a preliminary pressure is applied. In this state, the temporarily fixing detent screw 180 is fastened and fixed. In this case, the gear teeth of the first backlash removing sub gear 120 and the gear teeth of the first main gear 110 coincide in a circumferential direction with no phase difference. When the first backlash-removing gear assembly 100 is engaged with the first drive gear 12 and then the temporary fixing detent screw 180 is removed in this state, the resilient restoring force of the first elastic ring 140 is reduced by the driving force So that the first backlash removing sub gear 120 is rotated in the driving force transmitting direction.

5, in a state in which the first drive gear 12 rotates in the driving force transmitting direction to transmit the rotational force to the first main gear 110, the leading tooth surface 12a of the first drive gear 12 1 side gear face 110b of the main gear 110 and transmits the rotational force. As a result, backlash occurs between the follower tooth surface 12b of the first drive gear 12 and the leading tooth surface 110a of the first main gear 110.

In this case, the first backlash removing sub gear 120 receives the elastic restoring force of the first elastic ring 140 and is further rotated in the driving force transmitting direction, which is the same direction as the first drive gear 12, The tooth surface is pressed against the follower tooth surface 12b of the first drive gear 12 so that the backlash is removed.

6 is a view for explaining the driving force transmission direction, the twist direction of the helical gear, and the positional relationship between the first drive gear 12 and the first backlash removing sub gear 120. As shown in Fig. Figure 6 (a) on the left side of Figure 6 shows a bad example, and Figure (b) on the right side shows a preferred example. See FIG. 3 in parallel.

3 and 6, the leading tooth surface 12a of the first drive gear 12 is pressed against the follower tooth surface 110b of the first main gear 110 to transmit the rotational force, A backlash is generated between the follower tooth surface 12b of the first drive gear 12 and the leading tooth surface 110a of the first main gear 110. [ The first backlash removing sub gear 120 receives the resilient restoring force of the first elastic ring 140 and presses the leading tooth surface of the first backlash removing sub gear 120 against the follower tooth surface 12b of the first drive gear 12 .

For example, the helical gear generates thrust in the axial direction in accordance with the rotation direction or the torsion direction. Therefore, when the first backlash removing sub gear 120 presses the follower tooth surface 12b of the first drive gear 12 by the elastic restoring force of the first elastic ring 140, the twist angle of the helical gear So that the first backlash removing sub gear 120 slips along the inclined surface and receives a force to move it.

6 (a), between the first main gear 110 and the first backlash removing sub gear 120, there is provided a first backlash removing sub gear 120 in the axial direction To maintain a fine clearance. At this time, when the thrust direction of the first backlash removing sub gear 120, that is, the sliding direction acts in a direction away from the first main gear 110, the first backlash removing sub gear 120 is moved by the existing axial clearance, If the resistance force acts intermittently in the opposite direction, the rotation of the gear will not be stable because the movement will occur repeatedly.

6 (b), the elastic force of the first elastic ring 140 causes the first backlash removing sub gear 120 to move toward the follower tooth surface of the first drive gear 12, (12b) of the first drive gear (12) so as to receive a thrust force which is slid in the axial direction and brought into close contact with the first main gear (110) side by the twist angle of the follower tooth surface (12b) of the first drive gear The driving force transmission direction and the arrangement direction of the first backlash removing sub gear 120 (that is, one of the both side surfaces of the first main gear 110) are set.

6 (b), the thrust direction c of the first backlash removing sub gear 120 is directed downward, so that the first backlash removing sub gear 120 is in the downward direction, The axial clearance between the first backlash removing sub gear 120 and the first main gear 110 is removed so that the driving is stably performed, So that it is possible to process the gear of the road.

7A to 7C illustrate a second backlash elimination gear assembly 200 according to the present invention, wherein a side view is shown in FIG. 7A, and a cross-sectional view taken along line CC in FIG. 7A is shown in FIG. And FIG. 7C is a cross-sectional view taken along line DD of FIG. 7A. Hereinafter, FIG. 3 will be referred to concurrently.

As previously described, the second backlash elimination gear assembly 500 is only the same size as the first backlash elimination gear assembly 100, but the configuration is the same.

However, in the actual hobbing machine, the twist direction of the helical gear of the first gear pair consisting of the first drive gear 12 and the first backlash elimination gear assembly 100 according to the above- The helical gears of the second gear pair consisting of the second drive gear 22 and the second backlash eliminating gear assembly 500 are twisted in opposite directions. This is because the driving force transmission direction is reversed in the course of power transmission from the first axis 10 to the third axis 30 via the second axis 20, as can be seen from Fig.

As shown in FIGS. 3, 7A-7C, the second backlash elimination gear assembly 500 is similar to the first backlash elimination gear assembly 100 described above from the operative end of the gear transmission system A second main gear 510 meshing with a second drive gear 22 driven in a direction of transmission of a driving force to be resisted and in a simple rotation direction that simply rotates in the opposite direction without being subjected to a resistance force from the operative end; The second main gear 510 and the second main gear 510. The first main gear 510 and the second main gear 510 are slidably coupled to one axial side surface 512 of the second main gear 510, A second backlash removing sub gear (520) meshing with the second backlash removing gear (520); A second fixing plate 530 that integrally couples the second main gear 510 to the second backlash removing sub gear 520 while slidably covering the outer surface of the second backlash removing sub gear 520; A second annular groove 516 having a square cross section formed on the contact surfaces 512 and 522 of the second main gear 510 and the second backlash removing sub gear 520; (542) and (544) formed at both ends in the circumferential direction so as to be slidably installed in the second annular groove (516), which is formed by an annular elastic body of a section rectangle from which a part of the circumference is removed, The fixing hole 544 is fixed to the second backlash removing sub gear 520 by inserting the fixing bolt 560 fastened from the second backlash removing sub gear 520, And a second elastic ring 540 into which a fixing bolt 570 fastened from the second main gear 510 is inserted and fixed to the second main gear 510. [

A provisional fixing screw hole 536 is formed in the second fixing plate 530 so as to face the outer side surface 526 of the second backlash removing sub gear 520. The provisional fixing screw hole 536 A preload is applied to the second elastic ring 540 by pressing the outer surface 526 of the second backlash removing sub gear 520 in the axial direction and pushing it against the side surface 512 of the second main gear 510 A provisional fixing detent screw 580 for temporarily fixing the second backlash removing sub gear 520 to the second main gear 510 is fastened in the second state.

A plurality of arcuate guide grooves 538 are formed in the second fixing plate 530 and circular arc guide grooves 538 of the second fixing plate 530 are formed in the second backlash removing sub gear 520. [ The rotation range of the second backlash removing sub gear 520 with respect to the second main gear 510 and the second fixing plate 530 is limited and the rotation is guided.

The second annular groove 516 having a square cross section is recessed at a predetermined depth from the surface of the inner side surface 522 of the second backlash removing sub gear 520 and has a second annular second elasticity The ring 540 is in sliding contact with the inner surface of one side 512 of the second main gear 510 and the inner surface of the second annular groove 516 in the second annular groove 516,

Fig. 8 is a main detail view for explaining the backlash removing principle of the second backlash removing gear assembly. Fig.

The second backlash removing sub gear 520 is moved in the opposite direction to the driving force transmitting direction with respect to the second main gear 510 before the second backlash removing gear assembly 200 is engaged with the second drive gear 22 And a preliminary pressure is applied. In this state, the temporarily fixing detent screw 580 is fastened and fixed. In this case, the gear teeth of the second backlash removing sub gear 520 and the gear teeth of the second main gear 510 coincide in a circumferential direction with no phase difference. In this state, when the second backlash removing gear assembly 500 is assembled by engaging with the second drive gear 22 and then the temporary fixing detent screw 580 is removed, the elastic restoring force of the second elastic ring 540 is reduced by the driving force So that the second backlash removing sub gear 520 is rotated in the driving force transmitting direction.

8, in a state in which the second drive gear 22 rotates in the driving force transmitting direction to transmit the rotational force to the second main gear 510, the leading tooth surface 22a of the second drive gear 22 2 main gear 510, and transmits the rotational force. As a result, backlash occurs between the follower tooth surface 22b of the second drive gear 22 and the leading tooth surface 510a of the second main gear 510.

In this case, the second backlash removing sub gear 520 receives the elastic restoring force of the second elastic ring 540 and is further rotated in the driving force transmitting direction, which is the same direction as the second drive gear 22, The backlash is removed by closely pressing the tooth surface against the follower tooth surface 22b of the second drive gear 22.

On the other hand, the direction of the preload applied to the second elastic ring 540 is the same as the principle of the preload applied to the first elastic ring 140 so that the second backlash removing sub gear 520 is moved in the driving force transmitting direction And is set in a direction to provide an elastic restoring force to push against the follower tooth surface 22b of the second drive gear 22. [

The torsional direction and the driving force transmission direction of the helical gears of the sub gears of the second drive gear 22, the second main gear 510 and the second backlash eliminating sub gear 520 are the same as those of the second elastic ring 540, Of the second drive gear 22 when the second backlash removing sub gear 520 is elastically brought into close contact with the follower tooth surface 22b of the second drive gear 22 by the elastic restoring force of the second backlash removing sub- 22b so as to be brought into close contact with the second main gear 510 in the axial direction.

9 is a graph comparing the tooth surface condition measurement graphs of the gears cut in the hobbing machine to which the conventional drive device and the drive device using the backlash removing gear assemblies 100 and 500 according to the present invention are applied. The tooth surface state is measured by moving the probe from the root portion to the tip at a point in the axial direction of the gear teeth. The 'standard gear' is a gear measured in a state in which a gear And the 'backlash eliminating gear' represents a gear processed in a state in which the driving apparatus to which the backlash eliminating gear assembly 100, 500 according to the present invention is applied. In the graphs on the left and right of each graph, one surface and the opposite surface of one gear are measured.

As shown in FIG. 9, the gears fabricated in the hobbing machine to which the backlash-removing gear assemblies 100 and 500 according to the present invention are applied have a tooth profile and an extremely high roughness And it can be seen that it is cut uniformly.

This is because the backlash eliminating gear assemblies 100 and 500 effectively remove the resistance force and the shaking due to the intermittent resistance acting in the direction opposite to the driving force transmitting direction during the cutting of the gear with the hob cutter 40, Results.

The foregoing is a description of certain preferred embodiments of the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, .

10: 1st axis
12: first drive gear
12a, 22a, 110a, 510a:
12b, 22b, 110b, 510b:
20: Second axis
22: second drive gear (22)
30: 3rd axis
40: Hob cutter
100, 500: Backlash removal gear assembly
110, 510: main gear
112, 122, 126, 512, 522:
114, 134: Boss
116, 516: annular groove
120, 520: Sub gear for backlash removal
130, 530: Fixing plate
132, 532: flange
136, 536: temporary fixing screw hole
138, 538: circular arc guide groove
139, 539: guide shaft
140, 540: elastic ring
142, 144, 542, 544: fixing holes
150, 550, 160, 170, 560, 570: Fixing bolts
180, 580: Temporary fixing detent screw

Claims (6)

A main gear meshing with a drive force transmitting direction that receives a resistance force from an operative end of the gear power transmission system and a drive gear that is driven in a simple rotation direction that simply rotates in the opposite direction without being subjected to a resistance force from the operative end;
A backlash removing sub gear having the same number and tooth profile as the main gear and slidably coupled to one axial side of the main gear to engage with the drive gear together with the main gear;
A fixed plate integrally coupled to the main gear while blocking the outer surface of the backlash removing sub gear in a slidable state;
An annular groove having a square cross section formed on the contact surface of the main gear and the backlash removing sub gear;
And a fixing hole is formed at both ends in the circumferential direction so that one of the fixing holes is fastened from the backlash removing sub gear, And the opposite fixing hole includes an elastic ring to which a fixing bolt fastened from the main gear is inserted and fixed to the main gear,
Wherein a plurality of arcuate guide grooves are formed in the fixed plate and a guide shaft passing through the arcuate guide grooves of the stationary plate is coupled to the backlash removing sub gears so that the backlash is removed from the main gear and the stationary plate, And the rotation range of the sub gear is limited and the rotation is guided. The method according to claim 1,
Wherein the fixed plate is formed with a temporary fixing screw hole facing the outer side surface of the backlash removing sub gear and the outer side surface of the backlash removing sub gear is axially pressed into the temporary fixing screw hole, And a temporarily fixing detent screw for temporarily fixing the backlash removing sub gear so as not to rotate with respect to the main gear is fastened in a state where a preload is applied to the elastic ring by pushing to the side of the main gear. Lash removal gear assembly. delete The method according to claim 1,
The annular groove having a square cross section is recessed at a predetermined depth from the inner surface of the backlash removing sub gear,
Wherein said annular resilient ring of said cross-sectional rectangular shape has both side surfaces in said annular groove in sliding contact with one side of said main gear and an inner surface of said annular groove, respectively. A spindle drive device for a hobbing machine for driving a hob cutter (40) provided at an operative end of a power transmission system for cutting a gear,
A first drive gear that is rotated in a simple rotation direction that is rotated only in a reverse direction without receiving a resistance force and a driving force transmission direction in which a driving force is received from a driving source and is subjected to a resistance force in accordance with gear cutting from a hob cutter (10) having a first drive gear (12) and the first drive gear (12);
A second shaft 20 disposed in parallel with the first shaft 10;
The first backlash removing gear assembly (100) according to any one of claims 1, 2, and 4, which is installed on the second shaft (20) and engages with the first drive gear (12) ;
A second drive gear (22) provided on the second shaft (20) together with the first backlash removing gear assembly (100);
A third shaft 30 disposed in parallel to the second shaft 20 and having the hob cutter 40 mounted at one end thereof;
A second backlash elimination gear assembly (500) according to any one of claims 1, 2 or 4, which is mounted on the third shaft (30) and engaged with the second drive gear (22) And a main shaft driving unit for driving the main shaft of the hobbing machine. 6. The method of claim 5,
The helical twisting direction of the first gear pair consisting of the first drive gear 12 and the first backlash elimination gear assembly 100 and the helical twisting direction of the second drive gear 22 and the second backlash elimination gear assembly 500 Wherein the helical twisting directions of the second pair of gears are opposite to each other.

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