KR102341383B1 - A damping gear wheel structure - Google Patents

Abstract

A damping gear that can reduce the impact noise caused by backlash between gears when transmitting power through gear connection, and prevent damage due to wear or shear damage by blocking the occurrence of friction or concentrated load between components. It relates to a wheel structure.

Description

A damping gear wheel structure

The present invention relates to a damping gear wheel structure, which can reduce impact noise caused by backlash between gears when power is transmitted by gear connection, and blocks friction between components or generation of concentrated load to prevent wear caused by wear, etc. It relates to a damping gear wheel structure capable of preventing damage or shear damage.

For example, among power-assisted steering systems mounted on a vehicle, there is an electric power-assisted steering system in which steering force is controlled by a motor, which is controlled by an electronic control device according to the driving conditions of the vehicle detected by various sensors such as a vehicle speed sensor and a steering torque sensor. It drives the motor precisely, and the torque generated from the motor is transmitted to the steering column or pinion through the reducer, helping the driver to operate the steering wheel connected to the steering column and pinion.

Accordingly, it is possible to maintain optimal steering conditions for the driver, such as providing a light and comfortable steering state when driving at low speeds, providing a heavy and stable steering state when driving at high speeds, and enabling rapid steering operation in response to sudden emergency situations. It provides steering performance that enables

Such an electric power assist steering device is a gearbox equipped with a motor, such as a steering column part for fixing the steering shaft connecting the steering wheel of the driver's seat and the gearbox under the vehicle to the vehicle body, or a gearbox part with a built-in pinion coupled to the rack bar. It is installed and a device that allows the rotational force of the steering wheel operated by the driver to be transmitted to the rack bar by the motor and the reducer.

1 shows a reducer of an electric power-assisted steering device provided in a commonly used column, which is provided with a worm shaft 104 made of a metal material such as steel in which a worm 102 is formed in the middle portion, and the worm shaft Worm bearings 106 are installed at both ends of 104 to support the worm shaft 104, and the worm shaft 104 and the motor shaft 108 are connected to each other to rotate the worm shaft 104 by driving the motor 110. has a structure that

A worm wheel 114 made of, for example, a resin composition is provided on one side of the outer diameter of the worm 102 so as to be meshed with the worm 102 formed in the middle portion of the worm shaft 104 as a reduction gear, and the worm wheel 114 is operated by a driver. It is mounted on the steering shaft 112 that transmits the rotational force of a steering wheel (not shown), and the rotational force of the worm shaft 104 by driving the motor 110 is transmitted to the steering shaft 112 . The worm wheel 114 and the worm shaft 104 meshed in a worm gear manner are mounted inside the housing 116 for protection from the outside.

According to the driving conditions of the vehicle, an electronic control device (not shown) provided in the vehicle controls the driving of the motor 110 , and the rotational force of the worm shaft 104 by the driving of the motor 110 is the rotational force of the steering wheel operated by the driver. It is added to and transmitted to the steering shaft 112 so that the driver's steering driving state can be smoothly and stably maintained.

In the reducer as described above, vibration and rattle noise occur due to an increase in backlash due to wear of gear teeth. In particular, on off-road, these vibrations and rattle noise are transmitted to the interior of the vehicle. This causes discomfort to the driver.

An electric steering device for a vehicle that solves this problem is disclosed in Japanese Patent No. 3842215. It uses a ring-shaped elastic spacer having a plurality of protrusions on the outer periphery to alleviate the impact and impact noise caused by backlash between the worm and the worm wheel.

However, this device has a problem in that the functional life of the elastic spacer is shortened due to wear and the like during long-term use due to friction between the inner and outer peripheral surfaces of the elastic spacer with the counterpart element.

In addition, the damping worm wheel disclosed in Korean Patent Laid-Open No. 10-2014-0001288 includes a clutch 30 provided on one side of the worm wheel plate 20 and coupled to the steering shaft 4 of the vehicle, as shown in FIG. 1 ; , a resilient member 40 penetrating the clutch 30 and spaced apart from one side of the worm wheel plate 20 from the clutch 30 and having a hole formed therein, and the clutch 30 and the clutch 30 through the hole A coupling member 50 for coupling the worm wheel plate 20 is provided.

This has the advantage that it is possible to compensate for the clearance generated between the worm shaft 3 and the worm wheel plate 20 due to the repulsive force of the elastic member 40 and to alleviate the impact that is reversely input from the rack bar 6 and the like.

However, the damping worm wheel as described above must be processed so that each spacing gap between each fixing hole 32 of the clutch 30 and each coupling member 50 is the same, and is also coupled to the coupling member 50 and the spacing gap. Each of the elastic members 40 should be manufactured to have the same restoring force.

If these requirements are not met, when power is transmitted from the worm plate 20 to the steering shaft 4 through the coupling member 50, a concentrated load or repeated load is generated in one coupling member 50, resulting in shear damage. There are problems that could be.

Japanese Patent No. 3842215 Korean Patent Publication No. 10-2014-0001288

The present invention was created to solve the above problems, and it is possible to reduce the impact noise caused by backlash between the gears during power transmission by gear connection, and to block the occurrence of friction between the components or the generation of concentrated load. An object of the present invention is to provide a damping gear wheel structure capable of preventing damage or shear damage due to wear, etc.

The present invention, which achieves the above object, provides a damping gear wheel structure for reducing impact noise caused by backlash between a main gear and a gear wheel to which power is transmitted by meshing with the main gear,

An annular gear plate having gear teeth engaged with the main gear on an outer circumferential surface and having a plurality of engaging grooves formed on an inner circumferential surface;

An annular boss coupled to the coupling groove on the outer periphery, a plurality of protrusions having a relatively smaller width than the width of the coupling groove are formed, and a shaft hole is formed in the center to which the shaft is coupled;

a first damper adhered to one surface of the boss;

and a first hub attached to an inner peripheral surface of the gear plate and a surface of the first damper.

In addition, the structure of the present invention is characterized in that it further includes a second damper attached to the other surface of the boss, and a second hub attached to the inner circumferential surface of the gear plate and the surface of the second damper.

In addition, in the structure of the present invention, the first and second dampers are formed in an annular shape and have first and second vertical portions extending vertically from the inner edge, extending up and down from the shaft hole edge of the boss, and the first and second vertical portions It is characterized in that the first and second annular protrusions to be adhered are formed.

In addition, the structure of the present invention is characterized in that the first and second dampers have a sectoral shape that increases in width from the center of the boss toward the outer periphery, and a plurality of dampers are provided.

In addition, the structure of the present invention is characterized in that a plurality of buffer holes are formed in the first and second dampers.

In addition, in the structure of the present invention, the first and second dampers are alternately formed with convex portions and concave portions on their upper surfaces in the circumferential direction, and each of the convex portions is formed in a sectoral shape that increases in width from the center of the boss to the edge. characterized.

First, the boss 220 is relatively rotated with respect to the gear plate 210 in the clearance range between the coupling groove 212 of the gear plate 210 and the projection 221 of the boss 220, and the first, 2 By bonding the dampers 230 and 250 to the boss 220, the shock and noise caused by backlash are reduced, and friction between components is prevented, thereby extending the life of the damper.

Second, by configuring a plurality of sector-shaped first and second dampers to be spaced apart from the case where the first and second dampers 230 and 250 formed integrally with respect to the surface of the boss 220 are adhered to each other, the elastic restoration function is smoothly performed. It allows to increase the damping efficiency.

Third, by forming buffer holes 232 and 252 in the first and second dampers 230 and 250 , elastic deformation and restoration are made more smoothly.

Fourth, the first and second dampers 430 and 530 are alternately formed with convex portions 230a and concave portions 230b on the upper surface in the circumferential direction, and each convex portion 230a is formed in a sectoral shape. 1, 2, the dampers 430, 530 are easily attached to the boss 220, and elastic deformation and restoration are facilitated by the convex portion 230a to increase the damping efficiency.

1 is a cross-sectional view showing a reducer of a conventional electric power assist steering device;
2 is a cross-sectional view showing a conventional damping worm wheel;
3 is a partial cross-sectional perspective view of a damping gear wheel according to an embodiment of the present invention;
Figure 4 is an exploded perspective view of Figure 3;
5 is a schematic diagram of the coupling state of the gear plate and the boss;
6 is a perspective view of a state in which a first damper of another embodiment is attached to a boss;
7A and 7B are explanatory views of the operating state of the first damper of the FIG. 6 embodiment;
8 is a perspective view of main parts showing first and second dampers according to another embodiment.

The damping gear wheel structure of the embodiment of the present invention corresponds to the worm wheel employed in the reducer of the electric power assist steering device as shown in FIG. do.

3 and 4, in the gear wheel structure 200 according to the embodiment of the present invention, a worm (main gear) rotationally driven by the power of a motor is geared and decelerated to transmit power to the steering shaft (refer to FIG. 2). do.

3 to 5, the gear wheel structure 200 of the embodiment of the present invention is an annular gear having a gear tooth 211 meshed with the main gear on an outer peripheral surface and a plurality of coupling grooves 212 formed on an inner peripheral surface. The plate 210 and a plurality of projections 221 coupled to the coupling groove 212 on the outer periphery and having a width relatively smaller than the width of the coupling groove 212 are formed in the center of the shaft (steering shaft; 300) An annular boss 220 having a shaft hole 222 coupled thereto, an elastic first damper 230 adhered to one surface of the boss 220, an inner peripheral surface of the gear plate 210, and the first damper A first hub 240 adhered to the surface of the 230 is provided.

In the gear wheel structure having such a configuration, the rotational force of the main gear (worm) is applied to the shaft 300 via the gear plate 210 , the first hub 240 , the first damper 230 and the boss 220 sequentially. will be transmitted

At this time, when an impact between the gear teeth due to backlash between the main gear and the gear teeth 211 occurs, a rotational phase difference is generated between the gear plate 210 and the boss 220 .

That is, referring to FIG. 5 , the boss 220 is relatively rotated with respect to the gear plate 210 in the clearance range between the coupling groove 212 of the gear plate 210 and the projection 221 of the boss 220, At this time, the impact and noise thereof are reduced by the elasticity of the first damper 230 of the rubber material.

Meanwhile, an elastic second damper 250 is attached to the other surface of the boss 220 , and a second hub 260 is further attached to the inner peripheral surface of the gear plate 210 and the surface of the second damper 250 . do.

In this case, power transmission from the gear plate 210 to the boss 220 is more stable, and the first and second dampers 230 and 250 can stably damp the shock and noise of the gear teeth according to the backlash. make it possible

In addition, the first and second dampers 230 and 250 are formed in an annular shape and include first and second vertical portions 231 and 251 extending vertically from the inner edge, and the shaft hole ( 222) The first and second annular protrusions 223 and 224 to which the first and second vertical portions 231 and 251 are adhered are formed on the edges.

In this case, the contact area between the first and second hubs 240 and 260 and the boss 220 is increased to achieve more stable power transmission and damping.

Meanwhile, referring to FIGS. 6 and 7 showing another embodiment of the present invention, a plurality of the first and second dampers 230 and 250 may be configured to be spaced apart from each other at regular intervals on the surface of the boss 220 . .

Since the rotational displacement increases from the center of the boss 220 toward the outer periphery, it is preferable that the first and second dampers 230 and 250 are formed in a sectoral shape with a greater width toward the outer periphery.

In this case, as in the case of the first and second dampers 230 and 250 formed integrally with respect to the surface of the boss 220 as in the gear wheel structure of FIGS. 3 and 4, the first and second dampers ( By configuring a plurality of 230 and 250 spaced apart from each other, it is possible to increase the damping efficiency by smoothing the elastic restoration function.

That is, referring to FIGS. 7A and 7B , the first, by backlash when power is transmitted through gear meshing between the main gear (worm; not shown) driven by a motor and the gear teeth 211 of the gear plate 210, When a rotational phase difference occurs between the 2 hubs 240 and 260 and the boss 220, the left and right sidewalls of the first and second dampers 230 and 250 in the sectoral shape become free surfaces to facilitate elastic deformation and restoration. do.

In particular, when the buffer holes 232 and 252 are formed in the first and second dampers 230 and 250 , elastic deformation and restoration are made more smoothly, and when the first and second dampers 230 and 250 are applied, According to the degree of elasticity, the formation position and number of the buffer holes 232 and 252 may be reflected in the design.

Meanwhile, FIG. 8 shows the first and second dampers 430 and 530 of another embodiment, which alternately forms convex portions 230a and concave portions 230b on its upper surface in the circumferential direction, and each The convex portion 230a is formed in a sectoral shape that increases in width from the center to the edge of the boss 220 .

In this embodiment, it is easy to attach the first and second dampers 430 and 530 to the boss 220, and elastic deformation and restoration by the convex portion 230a are facilitated to increase the damping efficiency.

210...gear plate 211...gear tooth
212...combination groove 220...boss
230,250...1st & 2nd damper 240,260...1st & 2nd hub
300...shaft (steering shaft)

Claims (6)

In the damping gear wheel structure for reducing impact noise due to backlash between the main gear and the gear wheel meshed with the gear to transmit power,
An annular gear plate 210 having gear teeth 211 engaged with the main gear on the outer peripheral surface and having a plurality of engaging grooves 212 on the inner peripheral surface,
It is coupled to the coupling groove 212 on the outer periphery, a plurality of projections 221 having a relatively smaller width than the width of the coupling groove 212 are formed, and a shaft hole 222 to which the shaft 300 is coupled is formed in the center. Annular boss 220 and,
An elastic first damper 230 adhered to one surface of the boss 220;
By providing a first hub (240) adhered to the inner peripheral surface of the gear plate (210) and the surface of the first damper (230),
The damping gear wheel structure, characterized in that the first damper (230) reduces the impact and noise caused by backlash. The method according to claim 1, wherein the second damper (250) of elasticity adhered to the other surface of the boss (220), and a second hub (250) adhered to the inner peripheral surface of the gear plate (210) and the surface of the second damper (250). 260), further comprising a damping gear wheel structure. The method according to claim 2, wherein the first and second dampers (230, 250) are formed in an annular shape and include first and second vertical portions (231, 251) extending vertically from the inner edge,
It is characterized in that the first and second annular protrusions 223 and 224 extending up and down from the edge of the shaft hole 222 of the boss 220 and to which the first and second vertical portions 231 and 251 are adhered are formed. Damping gearwheel structure. The damping according to claim 2, wherein the first and second dampers (230, 250) have a sectoral shape that increases in width from the center of the boss (220) toward the outer periphery, and a plurality of dampers are provided spaced apart at regular intervals. gear wheel structure. The damping gear wheel structure according to claim 4, wherein a plurality of buffer holes (232, 252) are formed in the first and second dampers (230, 250). The method according to claim 2, wherein the first and second dampers (230, 250) doedoe convex portions (230a) and concave portions (230b) are alternately formed on the upper surface in the circumferential direction,
Each of the convex portions 230a is formed in a sectoral shape that increases in width from the center to the edge of the boss 220,
The damping gear wheel structure, characterized in that the shock and noise caused by backlash are reduced by the elastic deformation of the convex portion (230a).

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