KR102643774B1 - Worm reducer for vehicle - Google Patents

Abstract

These embodiments relate to a worm reducer for a vehicle, which is built into the shaft receiving part of the gear housing, and has a first bearing coupled to one end and a second bearing coupled to the other end, and a worm shaft and first bearing that rotate in conjunction with a worm wheel. It is attached to the outer circumference of the bearing case and is built into the shaft receiving part, and has guide members made of low-friction material on both sides. One end is coupled to the outer circumferential surface of the ring case, and the other end is supported on the inner circumferential surface of the gear housing to form a bearing case. A worm reducer for a vehicle including a case support member supporting in the radial direction is provided.

Description

Worm reducer for vehicles {WORM REDUCER FOR VEHICLE}

These embodiments relate to a worm reducer for a vehicle, and more specifically, a worm reducer for a vehicle, which compensates for moisture absorption of the worm wheel and clearance due to wear of the worm wheel, reduces rattle noise caused by impact noise and backlash transmitted from the road surface, and reduces rotational torque. This relates to a worm reducer for a vehicle that can accurately assist the driver's steering wheel operation force by minimizing the amount of clearance change due to changes in .

In general, a worm reducer for a vehicle controls the driving of the motor by an electronic control device provided in the vehicle according to the vehicle operating conditions, and the rotational force of the worm shaft caused by the driving of the motor is added to the rotational force of the steering wheel operated by the driver to drive the steering shaft. This is to ensure that the driver's steering driving condition is maintained smoothly and stably.

However, the conventional worm reducer for a vehicle has problems in that jamming occurs due to a change in clearance between the worm shaft and the worm wheel due to expansion due to moisture absorption of the worm wheel, resulting in excessive operating force, noise, and reduced durability.

In addition, the conventional worm reducer for a vehicle had a problem in that noise was generated due to clearance caused by wear as the durability of the worm shaft and worm wheel rotated by the driving of the motor progressed.

In addition, there was a problem of rattle noise occurring due to shock transmitted from the road surface to the worm wheel through the wheel and steering shaft or pinion shaft. Due to these problems, it was not possible to accurately provide steering assistance force that assists the driver's steering wheel operation force. There were also problems that did not exist.

Therefore, recently, in worm reducers for vehicles, the gap caused by moisture absorption and wear of the worm wheel is compensated, the impact sound transmitted from the road surface and rattle noise caused by backlash are reduced, and the amount of clearance change due to changes in rotation torque is minimized, thereby improving the driver's safety. There is a need for research on worm reducers for vehicles that can accurately assist steering wheel operation.

Against this background, the present embodiments compensate for the gap caused by the moisture absorption of the worm wheel and the wear of the worm wheel, reduce the impact sound transmitted from the road surface and rattle noise due to backlash, and minimize the amount of clearance change due to the change in rotation torque, thereby improving the driver's steering. It is possible to provide a worm reducer for vehicles that can accurately assist wheel operating force.

Additionally, the problems to be solved by the present embodiments are not limited here, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

In order to achieve the above-described object, the present embodiments include a worm shaft that is built into the shaft receiving part of the gear housing and has a first bearing coupled to one end and a second bearing coupled to the other end and rotates in conjunction with the worm wheel. 1A bearing case that is attached to the outer circumference of the bearing and is built into the shaft receiving part, and has guide members made of low friction material on both sides. One end is coupled to the outer circumference of the bearing case, and the other end is supported on the inner circumference of the gear housing. Provided is a worm reducer for a vehicle including a case support member that supports the case in the radial direction.

As described above, according to the present embodiments, in the worm reducer for a vehicle, the clearance due to moisture absorption and wear of the worm wheel is compensated, the impact noise transmitted from the road surface and rattle noise due to backlash are reduced, and the rotation torque is changed. By minimizing the amount of clearance change, it is possible to accurately assist the driver's steering wheel operation force.

1 is a perspective view showing a worm reducer for a vehicle according to the present embodiments.
Figure 2 is an exploded perspective view showing a worm reducer for a vehicle according to the present embodiments.
3 to 6 are perspective views showing a worm reducer for a vehicle according to the present embodiments.
7 to 10 are cross-sectional views showing worm reducers for vehicles according to the present embodiments.

Hereinafter, some embodiments of the present invention will be described in detail with reference to the exemplary drawings. In adding reference numerals to components in each drawing, the same components may have the same reference numerals as much as possible even if they are shown in different drawings. Additionally, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description may be omitted. When “comprises,” “has,” “consists of,” etc. mentioned in the specification are used, other parts may be added unless “only” is used. When a component is expressed in the singular, it can also include the plural, unless specifically stated otherwise.

Additionally, when describing the components of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the component from other components, and the nature, sequence, order, or number of the components are not limited by the term.

In the description of the positional relationship of components, when two or more components are described as being “connected,” “coupled,” or “connected,” the two or more components are directly “connected,” “coupled,” or “connected.” ", but it should be understood that two or more components and other components may be further "interposed" and "connected," "combined," or "connected." Here, other components may be included in one or more of two or more components that are “connected,” “coupled,” or “connected” to each other.

In the description of temporal flow relationships related to components, operation methods, production methods, etc., for example, temporal precedence relationships such as “after”, “after”, “after”, “before”, etc. Or, when a sequential relationship is described, non-continuous cases may be included unless “immediately” or “directly” is used.

On the other hand, when a numerical value or corresponding information (e.g., level, etc.) for a component is mentioned, even if there is no separate explicit description, the numerical value or corresponding information is related to various factors (e.g., process factors, internal or external shocks, It can be interpreted as including the error range that may occur due to noise, etc.).

1 is a perspective view showing a worm reducer for a vehicle according to the present embodiments, FIG. 2 is an exploded perspective view showing a worm reducer for a vehicle according to the present embodiments, and FIGS. 3 to 6 show a worm reducer for a vehicle according to the present embodiments. A perspective view and FIGS. 7 to 10 are cross-sectional views showing a worm reducer for a vehicle according to the present embodiments.

As shown in these drawings, the worm reducer 100 for a vehicle according to the present embodiments is built into the shaft receiving portion 111 of the gear housing 110, and a first bearing 127a is coupled to one end and the other A second bearing (127b) is coupled to the side end to form a worm shaft (101) that rotates in conjunction with the worm wheel (103). It is coupled to the outer circumference of the first bearing (127a) and is built into the shaft receiving portion (111), and has a worm shaft (101) on both sides. A bearing case 140 equipped with a guide member 143 made of friction material, one end of which is coupled to the outer peripheral surface of the bearing case 140, and the other end of which is supported on the inner peripheral surface of the gear housing 110 to support the bearing case 140. It includes a case support member 130 that supports in the radial direction.

The worm reducer 100 for a vehicle according to these embodiments engages and rotates with the worm shaft 101, which is coupled to the motor shaft and the coupler through a coupler to transmit the driving force of the motor, and outputs a reduced output. A worm wheel 103, etc. transmitted to a shaft (not shown) is mounted and mounted on the vehicle.

Here, since the motor (not shown), worm shaft 101, worm wheel 103, output shaft, etc. are parts commonly used in the technical field to which the present invention pertains, detailed description thereof will be omitted.

The worm shaft 101 is coupled by meshing a worm gear 101a formed in the central portion with a worm wheel gear 103a formed on the outer circumference of the worm wheel 103, and both ends of the worm shaft 101 are connected to the first bearing 127a. ) and is rotationally supported and coupled to the gear housing 110 by the second bearing 127b.

The gear housing 110 largely consists of a shaft receiving portion 111 and a worm wheel receiving portion 105.

The shaft receiving portion 111 is formed in a cylindrical shape and includes a cylinder portion 111a that communicates with the worm wheel receiving portion 105, and a motor connection portion 111b whose diameter is enlarged at the other end of the cylinder portion 111a and is coupled to the motor. An opening 112 is provided at one end of the cylinder portion 111a, and a worm shaft 101 is accommodated inside.

The worm wheel receiving portion 105 is formed in a cylindrical shape with one side open, and the shaft receiving portion 111 is formed integrally in the radial direction of the worm wheel receiving portion 105, and the center of the cylinder portion 111a is the worm wheel receiving portion 105. It is formed in communication with and is provided with a coupling hole 104 coupled to the shaft at the center of the worm wheel 103.

A cap member 120 that closes the opening 112 is coupled to one end of the cylinder portion 111a. A cap member 120 is press-fitted to one end of the cylinder portion 111a and a seating portion supported in the axial direction ( 116) is provided.

In addition, a fixing groove 115 formed as a radial groove is formed at one end of the cylinder portion 111a, and this fixing groove 115 supports the cap member 120 in the axial direction and supports the cap member 120. A fixing member 125 that prevents separation may be coupled.

In addition, threaded portions are formed on the outer peripheral surface of the cap member 120 and the inner peripheral surface of the opening 112, so that the cap member 120 can be screwed to the opening 112 of the gear housing 110.

In addition, a bearing case 140 is coupled to the outer circumference of the first bearing 127a and embedded in the shaft receiving portion 111, and guide members 143 made of a low friction material are provided on both sides of the bearing case 140. .

The guide member 143 is supported on the guide surface 113 formed on the shaft receiving portion 111, which will be described later, and is made of polytetrafluoroethylene (PTFE) or polyacetal (POM) to minimize friction when sliding. It is made of low friction materials such as poly oxy methylene).

The bearing case 140 coupled to one end of the worm shaft 101 has upper and lower outer peripheral surfaces 141 formed as curved surfaces opposing the inner peripheral surface of the shaft receiving portion 111, and the upper and lower ends of the bearing case 140. The two side portions 142 connecting are formed as a plane.

Here, the bearing case 140 is provided with fixing grooves 145 on both sides 142 formed in a plane, so that the guide member 143 can be coupled, and the shaft receiving portion 111 faces the guide member 143. Guide surfaces 113 formed as a plane are provided on both sides of the inner surface, so that the guide member 143 is supported on the guide surfaces 113 of the shaft receiving portion 111 and can move in a direction in which it engages with the worm wheel 103. .

In addition, the bearing case 140 may be integrally formed by coating both sides 142 formed in a plane with a guide member 143, and the shaft receiving portion 111 is formed on both sides of the inner surface opposite to the guide member 143. A guide surface 113 formed in a plane is provided so that the guide member 143 is supported on the guide surface 113 of the shaft receiving portion 111 and can move in a direction in which it engages with the worm wheel 103.

The bearing case 140 is provided with through holes 146 and 149 in the center of the worm shaft 101 in the axial direction, and these through holes 146 and 149 have small diameter portions 146 of different diameters. The large diameter portion 149 is formed to be connected stepwise in the axial direction.

Here, the small diameter portion 146 is disposed at the outer end of the bearing case 140, and the large diameter portion 149 is coaxially connected and formed to be disposed at the inner end of the bearing case 140.

In addition, the outer ring of the first bearing 127a is inserted and coupled to the large diameter portion 149, and the outer ring of the first bearing 127a is axially supported on the step portion 148 connected to the small diameter portion 146, When the first bearing (127a) and the worm shaft (101) are assembled in the bearing case (140), the axial position of the first bearing (127a) is assembled at the correct position, and the worm shaft (101) and the worm wheel (103) operate. This prevents noise caused by contact with the bearing case 140.

In addition, the upper outer peripheral surface of the bearing case 140 is provided with a coupling groove 147 into which one end of the case support member 130 is press-fitted, so that the first case member 133, which will be described later, is connected to the coupling groove 147. It is joined and fixed.

Therefore, during assembly, the bearing case 140 is assembled to the first bearing 127a coupled to the worm shaft 101, and the gear housing 110 is installed with the case support member 130 fixed to the bearing case 140. Assembly is performed by sliding on the shaft receiving portion 111, thereby preventing separation of the case support member 130 and making assembly easier.

The case support member 130 is formed in a cylindrical shape with one end closed and is coupled to the outer peripheral surface of the bearing case 140. The first case member 133 is formed in a cylindrical shape with the other end closed and is attached to the inner peripheral surface of the gear housing 110. The supported second case member 131, which is accommodated inside the first case member 133 and the second case member 131, has one end fixed to the first case member 133 and the other end to the second case member. It includes an elastic member 135 that is fixed to (131) and adds elastic force to one end and the other end.

Also, the first case member 133 and the second case member 131 are press-fitted or screwed together so as not to be separated from the elastic member 135 during assembly.

That is, the outer peripheral surface of the second case member 131 is supported on the inner peripheral surface of the first case member 133 and is press-fitted and separated, or the first screw portion 133a is formed on the inner peripheral surface of the first case member 133 and the second A second screw portion 131a is formed on the outer peripheral surface of the case member 131, so that the first case member 133 and the second case member 131 can be screwed together and separated.

One end (135-1) and the other end (135-2) of the elastic member 135 are press-fitted into the fixing grooves 132 provided in the first case member 133 and the second case member 131, respectively. It is fixed and remains connected by the elastic member 135 even if the first case member 133 and the second case member 131 are separated.

Therefore, when assembling, the first case member 133 is fixed to the coupling groove 147 of the bearing case 140, and the second case member 131 is separated from the first case member 133 to form the elastic member 135. Assembly is performed by sliding the second case member 131 onto the shaft receiving portion 111 of the gear housing 110 in a fixed state, preventing the components of the case support member 130 from being separated during assembly and making assembly easy. You lose.

Here, the first case member 133 and the second case member 131 are closely coupled to the bearing case 140 and the gear housing 110 so that sliding can occur, so that not only wear resistance and low friction but also a certain degree of bending and Since it is required to be made of a material that is rigid and has little elasticity due to heat, polyacetal (POM), polyamide (PA), polycarbonate (PC), polyimide (PI), and polybutylene terephthalate ( It can be made of engineering plastic-based materials such as PBT).

In addition, a gap D1 is provided between the lower end of the inner surface of the opening 112 of the shaft receiving portion 111 and the lower end of the bearing case 140. The wear amount during durability of the worm wheel 103, the worm shaft 101 and the worm wheel (103) is formed to have a gap D1 of 0.25 to 035 mm in consideration of the coupling operation force, etc.

In addition, a shock absorbing member 150 made of an elastic material is provided at the bottom of the inner surface of the opening of the shaft receiving portion 111 so that a gap D1 is provided between it and the bottom of the bearing case 140 to prevent shock generated from the road surface. When transmitted through the shaft and worm wheel 103, the shock absorbing member 150 is supported on the bearing case 140 and can absorb shock and noise.

Here, the shock absorbing member 150 is made of NR (Natural Rubber), NBR (Nitrile Butadiene Rubber), CR (Chloroprene Rubber), EPDM (Ethylene Propylene Terpolymer), and FPM (Fluoro Rubber) to have weather resistance and elasticity as well as elasticity. It is made of elastic materials such as SBR (Styrene Butadine Rubber), CSM (Chlorosulphonated Polyethylene), urethane, and silicon, and plays a damping role in absorbing noise and vibration.

In addition, a gap D2 is provided between the top of the inner surface of the shaft receiving portion 111 and the top of the bearing case 140, so that when the shock generated from the road surface is transmitted through the shaft and the worm wheel 103, the bearing case (140) directly collides with the gear housing 110 to prevent damage or deformation.

Here, the gap D2 formed between the top of the inner surface of the shaft receiving portion 111 and the top of the bearing case 140 is the gap D1 between the shock absorbing member 150 and the bottom of the bearing case 140. It can be formed the same or larger.

In addition, the opening 112 of the shaft receiving portion 111 is provided with a support step 119 at a position spaced axially inward from the guide surface 113, where the bearing case 140 is supported in the axial direction.

Therefore, when the bearing case 140 is combined with the first bearing 127a and the worm shaft 101 and assembled into the shaft receiving portion 111, the axial position of the bearing case 140 can be assembled at an accurate position. .

In addition, when the case support member 130 elastically supports the bearing case 140, the bearing case 140 is supported on the guide surface 113 and is supported on the support step 119 and engaged with the worm wheel 103. Sliding in any direction is possible.

In addition, the opening 112 of the shaft receiving portion 111 is provided with an opening groove 117 formed as a radial groove at the upper end of the inner surface at a position spaced axially outward from the support step 119, The second case member 131 of the case support member 130 is coupled to the opening groove 117.

Therefore, when assembling the bearing case 140 and the case support member 130 to the shaft receiving portion 111, the second case member 131 of the case support member 130 moves in the axial direction along the opening groove 117. Assembly is performed by sliding, and the case support member 130 is coupled in place.

Meanwhile, two or more case support members 130 may be provided. For example, when two case support members 130 are provided as shown in FIG. 10, when the worm shaft 101 is viewed in the axial direction, the worm shaft It may be arranged at the same angle A1 in the circumferential direction on both sides of a vertical line connecting the upper and lower centers of the bearing case 140 at the center of (101).

In addition, when the case support member 130 is provided in an odd number of two or more, one is placed on a vertical line connecting the upper and lower centers of the bearing case 140, and the rest are placed in the bearing case at the center of the worm shaft 101. By arranging them at the same angle A1 in the circumferential direction on both sides of the vertical line connecting the top and bottom centers of 140, the force supporting the bearing case 140 is evenly distributed.

In addition, when the case support members 130 are provided in an even number of two or more, they are positioned at the same angle (A1) in the circumferential direction on both sides of the vertical line connecting the center of the worm shaft 101 to the top and bottom centers of the bearing case 140. By arranging the force supporting the bearing case 140 is evenly distributed.

As described above, according to the present embodiments, in the worm reducer for a vehicle, the clearance due to moisture absorption and wear of the worm wheel is compensated, the impact noise transmitted from the road surface and rattle noise due to backlash are reduced, and the rotation torque is changed. By minimizing the amount of clearance change, it is possible to accurately assist the driver's steering wheel operation force.

The above description is merely an illustrative explanation of the technical idea of the present invention, and various modifications and variations will be possible to those skilled in the art without departing from the essential characteristics of the present invention. In addition, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention, but rather to explain it, and therefore the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted in accordance with the claims below, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of rights of the present invention.

100: Worm reducer 101: Worm shaft
103: worm wheel 105: worm wheel receiving portion
110: Gear housing 111: Shaft receiving portion
120: cap member 130: housing support member
131: second case member 133: first case member
135: elastic member 140: bearing case
150: Shock absorption member

Claims (15)

A worm shaft that is built into the shaft receiving part of the gear housing and has a first bearing coupled to one end and a second bearing coupled to the other end and rotates in conjunction with the worm wheel;
A bearing case coupled to the outer circumference of the first bearing and embedded in the shaft receiving unit, and having guide members made of a low friction material on both sides;
A case support member whose one end is coupled to the outer peripheral surface of the bearing case and the other end is supported on the inner peripheral surface of the gear housing to support the bearing case in the radial direction;
A worm reducer for a vehicle including a. According to claim 1,
The bearing case is a worm reducer for a vehicle, wherein the upper and lower outer peripheral surfaces are formed as curved surfaces opposing the inner peripheral surface of the shaft receiving portion, and both sides connecting the upper and lower ends are formed as flat surfaces. According to claim 2,
The bearing case is provided with fixing grooves on both sides formed in a plane plane to which the guide member is coupled, and the shaft receiving part is provided with guide surfaces formed in a plane plane on both sides of the inner surface opposite to the guide member, so that the guide member is connected to the guide member. A worm reducer for a vehicle, characterized in that it is supported on a surface. According to claim 2,
The bearing case is formed integrally with the guide member coated on both sides formed as a plane, and the shaft receiving part is provided with a guide surface formed as a plane on both sides of the inner surface opposite to the guide member, so that the guide member is formed on the guide surface. A worm reducer for a vehicle, characterized in that it is supported on. According to claim 2,
The bearing case is provided with an axial through hole at the center, and the through hole is a worm reducer for a vehicle in which small diameter portions and large diameter portions of different diameters are connected stepwise in the axial direction. According to claim 5,
A worm reducer for a vehicle, wherein the outer ring of the first bearing is coupled to the large diameter portion of the bearing case, and the outer ring of the first bearing is axially supported on a step where the small diameter portion and the large diameter portion are connected. According to claim 1,
A worm reducer for a vehicle, characterized in that the outer peripheral surface of the bearing case is provided with a coupling groove into which one end of the case support member is press-fitted and joined. According to claim 1,
The case support member is,
A first case member formed in a cylindrical shape with one end closed and coupled to the outer peripheral surface of the bearing case;
a second case member formed in a cylindrical shape with the other end closed and supported on the inner peripheral surface of the gear housing;
an elastic member accommodated inside the first case member and the second case member, one end of which is fixed to the first case member and the other end of which is fixed to the second case member to apply an elastic force to one end and the other end;
A worm reducer for a vehicle including a. According to claim 8,
A worm reducer for a vehicle, characterized in that the outer peripheral surface of the second case member is supported on the inner peripheral surface of the first case member and is press-fitted and separated. According to claim 8,
A worm for a vehicle, wherein a first screw portion is formed on the inner peripheral surface of the first case member and a second screw portion is formed on the outer peripheral surface of the second case member, so that the first case member and the second case member are screwed together and separated. reducer. According to claim 3,
A worm reducer for a vehicle, characterized in that a shock absorbing member made of elastic material is provided at the bottom of the inner surface of the opening of the shaft receiving portion. According to claim 11,
A worm reducer for a vehicle, characterized in that a radial gap is provided between the upper end of the shock absorbing member and the lower outer peripheral surface of the bearing case. According to claim 11,
A worm reducer for a vehicle, characterized in that a radial gap is provided between the upper inner surface of the shaft receiving portion and the upper outer peripheral surface of the bearing case. According to claim 11,
A worm reducer for a vehicle, wherein the shaft receiving portion is provided with a support step for supporting the bearing case in the axial direction at a position spaced axially inward from the guide surface. According to claim 14,
A worm reducer for a vehicle, wherein the shaft accommodating part is provided with an opening groove formed in a radial groove at an upper end of the inner surface at a position spaced axially outwardly from the support step to the end of the shaft accommodating part.

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