Rotor assembly for torque sensor

Abstract

The invention relates to a rotor assembly for a torque sensor. The rotor assembly of the torque sensor includes: a rotor having a through hole formed in an axial direction such that a steering shaft can be inserted into the through hole; a gear having a substantially annular shape and coupled to the rotor; and a fixing portion configured to fix the rotor to the gear. The fixed portion includes: at least one first coupling portion configured to fix the rotor to the gear with respect to an axial direction; and at least one second coupling portion configured to fix the rotor to the gear with respect to the rotational direction. Each of the first coupling portions includes an elastically deformable hook bent from the rotor and a hook groove penetrating the gear in a radial direction or recessed from a surface of the gear such that the hook is inserted into and caught by the hook groove.

Description

Technical Field

[0001] The present disclosure generally relates to a rotor assembly of a torque sensor, and more particularly, to a rotor assembly of a torque sensor capable of improving durability and wear resistance of the rotor assembly while reducing the number of parts of the rotor assembly. Background Art

[0002] Generally, a steering system of a vehicle is a system for changing the direction of wheels through a steering wheel to change the direction of travel of a moving vehicle. An electric power steering (MDPS) system is widely used in a steering system, which assists the steering force of a driver for driving safety and convenience, and the MDPS system includes a torque measuring device.

[0003] Torque measuring devices are usually equipped with a torque sensor.

[0004] Existing torque sensors have used welding between components or applied a separate component such as a retainer to fix the rotor to the gear. However, welding for fixing the rotor to the gear has resulted in increased complexity of the manufacturing process and manufacturing costs, and the application of a separate component has resulted in an increase in the number of components and a decrease in productivity due to an additional manufacturing process. In addition, in the case of using or applying a separate component to fix the rotor to the gear, severe wear may occur between the rotor and the housing due to the frequent rotation of the rotor during the driving of the vehicle, thereby reducing the durability and wear resistance of the product. Summary of the invention

[0005] According to an embodiment of the present disclosure, a rotor assembly of a torque sensor can firmly fix a rotor to a gear by or using a simple structure.

[0006] According to an embodiment of the present disclosure, a rotor assembly of a torque sensor can improve durability and wear resistance of the rotor assembly.

[0007] According to an embodiment of the present disclosure, a rotor assembly of a torque sensor can reduce the number of components of the rotor assembly.

[0008] According to an embodiment of the present disclosure, a rotor assembly of a torque sensor can simplify a process of manufacturing the rotor assembly.

[0009] According to an embodiment of the present disclosure, a rotor assembly of a torque sensor can improve product productivity and reduce manufacturing costs.

[0010] Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure.

[0011] According to one aspect of the present disclosure, a rotor assembly may include: a rotor, the rotor including a through hole penetrating the rotor in an axial direction, wherein a steering shaft passes through the through hole; a gear, the gear being annular in shape and coupled to the rotor; and a fixing portion, the fixing portion being configured to fix the rotor to the gear; wherein the fixing portion may include at least one first coupling portion and at least one second coupling portion, the at least one first coupling portion being configured to fix the rotor to the gear relative to the axial direction, the at least one second coupling portion being configured to fix the rotor to the gear relative to a rotational direction, and each of the first coupling portions may include a hook groove and a hook bent from the rotor and elastically deformable, the hook groove penetrating the gear in a radial direction or recessed from the gear, wherein the hook may be inserted into and caught by the hook groove.

[0012] The hook may include: a first base extending upward from the rotor and facing the inner circumferential surface of the gear; a bent portion bent from an end of the first base; and a locking portion extending downward from the bent portion and being caught by the hook groove.

[0013] A lower end of the locking portion may be in close contact with an upward surface of the hook groove.

[0014] Each of the second coupling portions may include: a support rib protruding inwardly from an inner peripheral surface of the gear; and a pair of press-fit ribs provided in the rotor and in close contact with both sides of the support rib.

[0015] Each of the press-fit ribs may include: a second base portion extending upward from the rotor; and a plurality of coupling protrusions protruding from a side surface of the second base portion in a circumferential direction and pressed to a side surface of the support rib.

[0016] An upper surface of each of the coupling protrusions may include an inclined press-fit guide surface.

[0017] Each of the first coupling portions may further include a support protrusion protruding from the gear and in close contact with at least one region of the bent portion.

[0018] The gear may further include a rotation support portion protruding outward from an outer peripheral surface of the gear, wherein at least a portion of the rotation support portion may contact the housing, and the rotation support portion may continuously extend in a circumferential direction on the outer peripheral surface of the gear.

[0019] A plurality of first coupling portions and a plurality of second coupling portions may be provided in such a manner as to be alternately arranged between the rotor and the gear along the circumferential direction.

[0020] The rotor assembly may further include a sleeve disposed inside the gear, having a hollow shape, and configured to rotate together with the steering shaft.

[0021] The sleeve may be made of a metal material, the gear may be made of a plastic material, and the gear may be disposed in the sleeve by insert molding.

[0022] Each of the first coupling portions may further include a hook guide surface provided at a lower end of an inner peripheral surface of the gear, wherein an inner diameter of the hook guide surface may gradually increase downward.

[0023] According to one aspect of the present disclosure, a rotor assembly may include: a rotor, the rotor including a through hole penetrating the rotor in an axial direction, wherein a steering shaft passes through the through hole; a gear, the gear being annular in shape and coupled to the rotor; and a fixing portion, the fixing portion being configured to fix the rotor to the gear; wherein the fixing portion may include at least one first coupling portion and at least one second coupling portion, the at least one first coupling portion being configured to fix the rotor to the gear relative to the axial direction, the at least one second coupling portion being configured to fix the rotor to the gear relative to a rotational direction, and each of the first coupling portions may include a hook rib and a hook protruding outward from an outer periphery of the gear, the hook rib penetrating the rotor in a radial direction or being recessed from the rotor, wherein the hook is inserted into and caught by the hook rib, and the hook rib is elastically deformable.

[0024] The hook rib may include: a first base extending upward from the rotor and facing the outer peripheral surface of the gear; and a hook groove penetrating the first base in the radial direction or recessed from the first base, wherein the hook is inserted into the hook groove.

[0025] The upper end of the hook may be in close contact with the downward surface of the hook groove.

[0026] Each of the second coupling portions may include: a support rib protruding inward from an inner peripheral surface of the gear; and a pair of press-fit ribs provided in the rotor and in close contact with both sides of the support rib, respectively.

[0027] Each of the press-fit ribs may include: a second base portion extending upward from the rotor; and a plurality of coupling protrusions protruding from a side surface of the second base portion in a circumferential direction and pressed to a side surface of the support rib.

[0028] An upper surface of each of the coupling protrusions may include an inclined press-fit guide surface.

[0029] The gear may further include a rotation support portion protruding outward from an outer peripheral surface of the gear, wherein at least a portion of the rotation support portion may contact the housing, and the rotation support portion may continuously extend in a circumferential direction on the outer peripheral surface of the gear.

[0030] A plurality of first coupling portions and a plurality of second coupling portions may be provided in such a manner as to be alternately arranged between the rotor and the gear in a circumferential direction.

[0031] The rotor assembly may further include a sleeve disposed inside the gear, having a hollow shape, and configured to rotate together with the steering shaft.

[0032] The sleeve may be made of a metal material, the gear may be made of a plastic material, and the gear may be disposed in the sleeve by insert molding.

[0033] The lower surface of the hook may include an inclined hook guide surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] These and / or other aspects of the present disclosure will become apparent and more easily understood through the following description of the embodiments in conjunction with the accompanying drawings:

[0035] Figure 1 is an exploded perspective view of a torque sensor including a rotor assembly according to an embodiment of the present disclosure;

[0036] Figure 2 is a perspective view of a rotor assembly according to an embodiment of the present disclosure;

[0037] Figure 3 is a top view of a rotor assembly according to an embodiment of the present disclosure;

[0038] Figure 4 is an exploded perspective view of a rotor assembly according to an embodiment of the present disclosure;

[0039] Figure 5 is another perspective view for illustrating a gear according to an embodiment of the present disclosure;

[0040] Figure 6is another perspective view for illustrating a rotor and a gear coupled to each other according to an embodiment of the present disclosure;

[0041] Figure 7 It is along Figure 3 A cross-sectional view taken along line AA';

[0042] Figure 8 is a perspective view of a rotor assembly according to another embodiment of the present disclosure;

[0043] Fig. 9 is a top view of a rotor assembly according to another embodiment of the present disclosure;

[0044] Fig.10 is an exploded perspective view of a rotor assembly according to another embodiment of the present disclosure;

[0045] Fig.11 is another perspective view for illustrating a gear according to another embodiment of the present disclosure;

[0046] Fig.12 is another perspective view for illustrating a rotor and a gear coupled to each other according to another embodiment of the present disclosure; and

[0047] Fig.13 It is along Fig. 9 A cross-sectional view taken along line BB'. DETAILED DESCRIPTION

[0048] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The following embodiments are provided to convey the concept of the present disclosure to those of ordinary skill in the technical field to which the present disclosure belongs. However, the present disclosure is not limited to these embodiments and may be embodied in another form. In the accompanying drawings, in order to clarify the present disclosure, parts not related to the present description may not be shown, and for ease of understanding, the sizes of the components are more or less exaggerated.

[0049] Figure 1 is an exploded perspective view of a torque sensor 1 including a rotor assembly 100 according to an embodiment of the present disclosure.

[0050] Reference Figure 1, the torque sensor 1 may include a housing 10, a rotor assembly 100, a sensor gear 20, a cover 30, and a printed circuit board (PCB). The housing 10 has a receiving space in which various components, such as a rotor 110 and a gear 120 to be described below, are received and mounted. The rotor assembly 100 is configured to be rotatable together with the steering shaft 40. The sensor gear 20 is engaged with the gear 120 and includes a magnetic material for measuring the steering angle of the steering shaft 40. The cover 30 covers the receiving space of the housing 10 and forms the appearance of the product together with the housing 10. Various electronic components are mounted to the PCB to detect the rotation of the rotor 110.

[0051] The housing 10 may include an installation opening that penetrates the housing 10 in the axial direction of the steering shaft 40, so that the steering shaft 40 and the rotor assembly 100 to be described below can penetrate the housing 10 through the installation opening and be installed in the installation opening. The housing 10 may have an accommodation space in which various components including the rotor assembly 100 and the PCB are accommodated and installed. The accommodation space of the housing 10 may be covered by the cover 30, and the housing 10 may be coupled to the cover 30 to form the housing and appearance of the torque sensor 1.

[0052] At least a portion of the rotor assembly 100 may be fixed to the steering shaft 40 and rotate together with the steering shaft 40. While the driver manipulates or controls the steering wheel (e.g., the driver rotates the steering wheel), the steering shaft 40 and the rotor assembly 100 may rotate accordingly, and the PCB may detect the magnetic induction current generated by the rotation of the rotor 110 to measure and detect the torque applied to the steering shaft 40.

[0053] In addition, the sensor gear 20 including a magnetic material may be rotatably engaged with the gear 120 of the rotor assembly 100. The sensor gear 20 may be rotated by the rotation of the steering shaft 40 and the gear 120, and the PCB may detect a change in a magnetic force or magnetic field generated by the rotation of the sensor gear 20 to detect and measure a steering angle of the steering wheel.

[0054] Meanwhile, if the torque sensor fixes the rotor of the rotor assembly to the gear by welding the rotor to the gear or by inserting a separate component between the rotor and the gear, the welding of the components has led to an increase in the complexity of the manufacturing process and an increase in the manufacturing cost, and the application of a separate component such as a retainer has led to an increase in the number of components and a decrease in productivity due to an additional installation process. In addition, relative rotation occurs between the housing and the gear that rotates repeatedly through the steering. However, in the torque sensor, due to the complex coupling structure, the area allowing relative rotation is small, which reduces the wear resistance and durability of the product.

[0055] For this reason, the rotor assembly 100 of the torque sensor 1 according to the embodiment of the present disclosure can firmly fix the rotor 110 to the gear 120 through a simple structure, while reducing the number of components of the torque sensor 1 and simplifying the manufacturing process of the torque sensor 1. In addition, the rotor assembly 100 can improve the wear resistance and durability of the product by expanding the area allowing relative rotation between the gear 120 and the housing 10.

[0056] Figure 2 is a perspective view of a rotor assembly 100 according to an embodiment of the present disclosure, Figure 3 is a top view of a rotor assembly 100 according to an embodiment of the present disclosure, and Figure 4 is an exploded perspective view of a rotor assembly 100 according to an embodiment of the present disclosure.

[0057] Reference Figures 2 to 4 The rotor assembly 100 of the torque sensor 1 according to the embodiment of the present disclosure may include a rotor 110, a gear 120, a sleeve 130, and a fixing portion 140. The rotor 110 has a through hole 110a through which the steering shaft 40 passes. The gear 120 is coupled to the rotor 110. The sleeve 130 is configured to be rotatable with the steering shaft 40 and is coupled to the gear 120. The fixing portion 140 is configured to fix the rotor 110 to the gear 120.

[0058] The rotor 110 may include a through hole 110a that penetrates the rotor 110 in the axial direction of the rotor 110 and through which the steering shaft 40 passes. The rotor 110 may be fixed to the steering shaft 40 (which will be described below) through the medium of the gear 120 and the sleeve 130 so as to rotate together with the steering shaft 40. The rotor 110 may include: a body 111 in which the through hole 110a is formed, and the body 111 has a substantially annular shape; and a plurality of blades 112 that protrude outwardly in a radial direction from the outer peripheral surface of the body 111. Slits may be formed between the blades 112 of the rotor 110. The rotor 110 may be made of a metal material to generate a magnetic induction current, and the blades 112 of the rotor 110 may rotate together with the steering shaft 40 by the rotation of the steering shaft 40. The PCB may detect the magnetic induction current generated by the rotation of the blades 112 of the rotor 110 to detect and measure the torque applied to the steering shaft 40 by the driver. A fixing portion 140 to be described below may be provided in the body 111 of the rotor 110 , and details about the fixing portion 140 will be described below.

[0059] The gear 120 may be generally annular in shape and may be fixed to the rotor 110 by a fixing portion 140 to be described below. In addition, the gear 120 may be rotated with the steering shaft 40 by means of a medium of the sleeve 130 by being coupled to the sleeve 130, which will be described below. A through hole 110a through which the steering shaft 40 passes may be formed in the interior of the gear 120, and therefore, the gear 120 may be generally annular in shape. The gear 120 may be made of, for example, but not limited to, a plastic material for product weight reduction and reduced operating noise. However, the gear 120 may be made of any suitable material. The gear 120 may be rotatably accommodated and supported in the accommodation space of the housing 10. The gear teeth 122 engaged with the sensor gear 20 may be formed at the upper portion of the gear 120, or arranged along the upper outer peripheral surface of the gear 120, and the fixing portion 140 to be described below may be disposed below the gear 120, or coupled to the lower portion of the gear 120.

[0060] The rotation support or the rotation support portion 121 may be disposed or formed between the gear teeth 122 and the fixed portion 140 (e.g., formed at the center between the gear teeth 122 and the fixed portion 140). The rotation support portion 121 may rotatably support the gear 120 in the accommodation space of the housing 10 and allow the gear 120 to rotate relative to the housing 10. For example, the rotation support portion 121 may protrude outward from the outer peripheral surface of the gear 120 in the radial direction of the gear 120, and at least a portion of the rotation support portion 121 may contact the housing 10 so as to receive wear caused by the relative rotation of the gear 120 relative to the housing 10.

[0061] In the rotor assembly 100 according to the embodiment of the present disclosure, since the fixing portion 140 fixes the rotor 110 to the gear 120 by or with the aid of a simple structure to be described below, the degree of freedom regarding the shape and size of the rotation support portion 121 can be increased, and therefore, the rotation support portion 121 can extend continuously in the circumferential direction on the outer peripheral surface of the gear 120. In other words, if the torque sensor has a limitation in ensuring the contact area between the housing and the gear by performing welding or inserting a separate component to fix the rotor to the gear, the contact area may be reduced, which deteriorates the wear resistance of the housing or the gear. However, according to the embodiment of the present disclosure, the rotor assembly 100 fixes the rotor 110 to the gear 120 by or with the aid of a simple structure, and therefore the rotation support portion 121 can have a substantially annular shape that continuously protrudes from the outer peripheral surface of the gear 120, and is rotatably supported to the housing 10. Thereby, the contact area between the housing 10 and the gear 120 can be enlarged, and therefore, the wear resistance between the housing 10 and the gear 120 can be improved despite repeated rotation of the gear 120 relative to the housing 10.

[0062] The sleeve 130 may have a hollow shape and include a through hole 130a through which the steering shaft 40 passes and is pressed. The sleeve 130 may be fixedly coupled to the steering shaft 40 so that the inner peripheral surface of the sleeve 130 presses the outer peripheral surface of the steering shaft 40. The sleeve 130 may be made of, for example, but not limited to, a metal material. However, the sleeve 130 may be made of any suitable material. At least a portion of the sleeve 130 may be arranged or disposed inside the gear 120. In order to simplify the process of assembling the sleeve 130 and the gear 120, the gear 120 may be manufactured by insert molding and coupled to the sleeve 130. Since the sleeve 130 is pressed into the steering shaft 40 and fixed to the steering shaft 40, the sleeve 130 is connected to the gear 120 by insert molding, and the gear 120 is connected to the rotor 110 by the fixing portion 140, which will be described below, the steering shaft 40, the sleeve 130, the gear 120 and the rotor 110 can be axially fixed and rotate together.

[0063] The fixing portion 140 may fix the rotor 110 to the gear 120 by means of or through a simple structure and a simple assembling process.

[0064] Figure 5 is another perspective view for illustrating the gear 120 according to an embodiment of the present disclosure, Figure 6 is another perspective view showing the rotor 110 and the gear 120 coupled to each other according to an embodiment of the present disclosure, and Figure 7 It is along Figure 3 A cross-sectional view taken along line AA'.

[0065] Reference Figures 4 to 7 , the fixing portion 140 may include: at least one first coupling portion 150 for fixing the rotor 110 to the gear 120 with respect to the axial direction; and at least one second coupling portion 160 for fixing the rotor 110 to the gear 120 with respect to the rotation direction or the circumferential direction. A plurality of first coupling portions 150 and a plurality of second coupling portions 160 may be provided in such a manner as to be alternately arranged between the rotor 110 and the gear 120 along the circumferential direction. The first coupling portions 150 and the second coupling portions 160 may be provided in various numbers as long as the first coupling portions 150 and the second coupling portions 160 can stably fix the rotor 110 to the gear 120.

[0066] One or more first coupling parts 150 may be provided between the rotor 110 and the gear 120 to fix the rotor 110 to the gear 120 with respect to the axial direction. Each of the first coupling parts 150 may include a hook 151, a hook groove 152, and a support protrusion 153. The hook 151 may extend or bend from the rotor 110. The hook groove 152 may be provided at or in the gear 120, and the hook 151 is inserted into and coupled to the hook groove 152. The support protrusion 153 may be provided in the gear 120, and the support protrusion 153 is in close contact with the hook 151.

[0067] The hook 151 may extend and bend from the body 111 of the rotor 110 and be elastically deformable or flexible to stably enter or be inserted into the hook groove 152 to be described below, and be coupled to the hook groove 152. The hook 151 may include a first base 151a, a bent portion 151b, and a locking portion 151c. The first base 151a may be bent and extended upward from the rotor 110 (e.g., in a direction perpendicular to the plane of the rotor 110). The bent portion 151b may extend and bend from the upper end of the first base 151a. The locking portion 151c may extend downward from the bent portion 151b.

[0068] The first base 151a may be generally in the shape of a plate extending upward from the inner peripheral surface of the blade 112 on the body 111 of the rotor 110. In a state where the rotor 110 and the gear 120 are assembled together, the first base 151a may be positioned inside the gear 120, and thus, the outward surface of the first base 151a may face the inner peripheral surface of the gear 120. The bent portion 151b may be bent outwardly and downwardly from the upper end of the first base 151a. As described above, the rotor 110 may be made of a metal material, and the bent portion 151b may be formed by bending the upper end of the first base 151a outwardly and downwardly.

[0069] The locking portion 151c may extend downward from the bent portion 151b and may be caught by or interlocked with the hook groove 152 of the gear 120, which will be described below. The lower end of the locking portion 151c may be in close contact with the upward surface of the hook groove 152, which will be described below, to prevent the rotor 110 from being disengaged or falling off from the gear 120, and to firmly fix the rotor 110 to the gear 120 with respect to the axial direction. Since the hook 151 is elastically deformable or flexible, when the rotor 110 and the gear 120 are assembled, the hook 151 may move toward the hook groove 152 while being pressed inwardly in the radial direction while in close contact with the inner circumferential surface of the gear 120, and when the locking portion 151c of the hook 151 is inserted into the hook groove 152, the hook 151 may be restored to its original shape by elastic restoring force to fix the rotor 110 to the gear 120 with respect to the axial direction. In order to enable the bent portion 151b and the locking portion 151c to easily enter the inner circumferential surface of the gear 120 or be inserted into the inner circumferential surface of the gear 120, and at the same time the hook 151 enters the outer circumferential surface of the gear 120 or is inserted into the outer circumferential surface of the gear 120 for assembling the rotor 110 and the gear 120, a hook guide surface 154 that is inclined so that the inner diameter gradually increases downward can be set at the lower end of the inner circumferential surface of the gear 120.

[0070] The hook groove 152 may penetrate the gear 120 or be recessed from the inner surface of the gear 120 so that the hook 151 may be inserted into the hook groove 152 and caught by the hook groove. The hook groove 152 may penetrate the gear 120 in the radial direction, and the locking portion 151c of the hook 151 may be inserted into the gear 120 from the inside of the gear 120 toward the outside of the gear 120 and interlocked or coupled with the gear 120 to fix the rotor 110 to the gear 120 relative to the axial direction. In addition, the upward surface of the hook groove 152 may be in close contact with the lower end of the locking portion 151c to prevent the rotor 110 from being disengaged or falling off from the gear 120. At the same time, Figures 3 to 7 An exemplary embodiment is shown in which the hook groove 152 penetrates the gear 120. Alternatively, the hook groove 152 may be recessed on or in the inner circumferential surface of the gear 120 in the radial direction so that the locking portion 151c of the hook 151 is inserted into the hook groove 152 and coupled thereto.

[0071] The support protrusion 153 may contact at least a portion of the curved portion 151b to support the hook 151. The support protrusion 153 may protrude from the inner circumferential surface of the gear 120 and closely contact the upper portion of the curved portion 151b to stably hold and support the hook 151 on the gear 120. The support protrusion 153 may be formed integrally with the gear 120 by injection molding of the gear 120 or at the time of injection molding of the gear 120.

[0072] One or more second coupling parts 160 may be positioned between the rotor 110 and the gear 120 to fix the rotor 110 to the gear 120 with respect to the rotation direction. Each of the second coupling parts 160 may include: a support rib 161 protruding from the gear 120; and a pair of press-fit ribs 162 provided in the rotor 110 and in close contact with both sides of the support rib 161 or the pair of support ribs 161, respectively.

[0073] The support rib 161 may protrude inwardly from the inner circumferential surface of the gear 120 in the radial direction. In addition, the support rib 161 may extend in the axial direction to be stably coupled to the press-fit rib 162. The pair of press-fit ribs 162 may be provided on the body 111 of the rotor 110 and positioned to both sides of the support rib 161 or positioned around both sides of the support rib 161 to be in close contact with both side surfaces of the support rib 161 and pressed to both side surfaces of the support rib 161, or to support both side surfaces of the support rib 161, thereby limiting the movement of the press-fit rib 162 in the circumferential direction. Each of the press-fit ribs 162 may include a second base 162a bent and extended upward from the rotor 110 and include a plurality of coupling protrusions 162b that protrude from the side surface of the second base 162a in the circumferential direction and are pressed to the side surface of the support rib 161 or to support the side surface of the support rib 161.

[0074] The second base 162a may be generally in the shape of a plate extending upward from the inner peripheral surface of the blade 112 on the body 111 of the rotor 110. When the rotor 110 and the gear 120 are assembled, the second base 162a may be positioned inside the gear 120, and thus, the outward surface of the second base 162a may face the inner peripheral surface of the gear 120. When the rotor 110 is coupled to the gear 120, a pair of second bases 162a may be positioned to both sides of each support rib 161, and coupling protrusions 162b protruding from the side surfaces of the second bases 162a may be in close contact with the side surfaces of the support rib 161 and pressed to the side surfaces of the support rib 161, thereby fixing the rotor 110 to the gear 120 with respect to the rotation direction.

[0075] The upward surface of each coupling protrusion 162b may include an inclined press-fit guide surface 162c. The press-fit guide surface 162c may be provided at the upward surface of the coupling protrusion 162b and may be inclined upward toward the side surface of the second base 162a. Therefore, the press-fit guide surface 162c may enable the support rib 161 to easily enter or be easily inserted between the pair of second bases 162a, and enable the coupling protrusion 162b to be easily pressed to the support rib 161 or support the support rib 161. In addition, the downward surface of the coupling protrusion 162b may have an angle corresponding to an angle perpendicular to the side surface of the second base 162a, thereby preventing the gear 120 from being disengaged or falling off from the rotor 110 in the axial direction.

[0076] Hereinafter, a rotor assembly 200 of a torque sensor 1 according to another embodiment of the present disclosure will be described.

[0077] Figure 8 is a perspective view of a rotor assembly 200 according to another embodiment of the present disclosure, Fig. 9 is a top view of a rotor assembly 200 according to another embodiment of the present disclosure, and Fig.10 is an exploded perspective view of a rotor assembly 200 according to another embodiment of the present disclosure.

[0078] Reference Figures 8 to 10 , the rotor assembly 200 of the torque sensor 1 according to an embodiment of the present disclosure may include a rotor 210, a gear 220, a sleeve 130, and a fixing portion 240. The rotor 210 may include a through hole 210a through which the steering shaft 40 passes. The gear 220 may be coupled to the rotor 210. The sleeve 130 may rotate with the steering shaft 40 and be coupled to the gear 220. The fixing portion 240 is configured to fix the rotor 210 to the gear 220.

[0079] The rotor 210 may include a through hole 210a. The through hole 210a may penetrate the rotor 210 along the axial direction of the rotor 210, and the steering shaft 40 passes through the through hole 210a. The rotor 210 may be fixed to the steering shaft 40 (which will be described below) by means of the medium of the gear 220 and the sleeve 130 so as to rotate with the steering shaft 40. The rotor 210 may include a body 211 and a plurality of blades 212. The body 211 may have a substantially annular shape, and the through hole 210a is formed in the body 211. The plurality of blades 212 may protrude outwardly from the outer peripheral surface of the body 211 in a radial direction. The rotor 210 may be made of, for example, but not limited to, a metal material to generate a magnetic induction current. However, the rotor 210 may be made of any material capable of generating a magnetic induction current. The blades 212 of the rotor 210 may rotate with the steering shaft 40 by the rotation of the steering shaft 40. The PCB may detect the magnetic induction current generated by the rotation of the blades 212 to detect and measure the torque applied to the steering shaft 40. A fixing portion 240 to be described below may be provided in the body 211 of the rotor 210 , and details about the fixing portion 240 will be described below.

[0080] The gear 220 may be generally annular in shape and fixed to the rotor 210 by a fixing portion 240 to be described below. In addition, the gear 220 may be coupled to the sleeve 130 to be described below so as to rotate with the steering shaft 40 by means of the medium of the sleeve 130. A through hole 210a through which the steering shaft 40 passes may be formed in the interior of the gear 220, and therefore, the gear 220 may be generally annular in shape. The gear 220 may be made of, for example, but not limited to, a plastic material for product weight reduction and operational noise reduction. However, the gear 220 may be made of any suitable material. The gear 220 may be rotatably accommodated and supported in the accommodation space of the housing 10. The gear teeth 222 engaged with the sensor gear 20 may be formed at the upper portion of the gear 220, or arranged along the upper peripheral surface of the gear 220, and the fixing portion 240 to be described below may be disposed below the gear 220, or coupled to the lower portion of the gear 220.

[0081] The rotation support or the rotation support portion 221 may be disposed or formed between the gear teeth 222 and the fixed portion 240 (e.g., formed at the center between the gear teeth 222 and the fixed portion 240 of the gear 220). The rotation support portion 221 may rotatably support the gear 220 in the accommodation space of the housing 10 and allow the relative rotation of the gear 220 relative to the housing 10. For example, the rotation support portion 221 may protrude outward from the outer peripheral surface of the gear 220 in the radial direction of the gear 220, and at least one region of the rotation support portion 221 may contact the housing 10 so as to receive wear caused by the relative rotation of the gear 220 relative to the housing 10.

[0082] In the rotor assembly 200 according to the embodiment of the present disclosure, since the fixing portion 240 fixes the rotor 210 to the gear 220 (which will be described below) by or with the aid of a simple structure, the degree of freedom regarding the shape and size of the rotation support portion 221 can be increased, and therefore, the rotation support portion 221 can extend continuously in the circumferential direction on the outer peripheral surface of the gear 220. In other words, if the torque sensor has a limitation in ensuring the contact area between the housing and the gear by performing welding or inserting a separate component to fix the rotor to the gear, the contact area may be reduced, which deteriorates the wear resistance of the housing or the gear. However, according to the embodiment of the present disclosure, the rotor assembly 200 fixes the rotor 210 to the gear 220 by or with the aid of a simple structure, and therefore the rotation support portion 221 can have a substantially annular shape that continuously protrudes from the outer peripheral surface of the gear 220, and is rotatably supported to the housing 10. Therefore, the contact area between the housing 10 and the gear 220 can be enlarged, and the wear resistance between the housing 10 and the gear 220 can also be improved despite the repeated rotation of the gear 220 relative to the housing 10.

[0083] The sleeve 130 may have a hollow shape and may be fixedly coupled to the steering shaft 40 so that the inner peripheral surface of the sleeve 130 presses the outer peripheral surface of the steering shaft 40. The sleeve 130 may be made of, for example, but not limited to, a metal material. However, the sleeve 130 may be made of any suitable material. At least a portion of the sleeve 130 may be arranged or disposed inside the gear 220. In order to simplify the process of assembling the sleeve 130 and the gear 220, the gear 220 may be manufactured by insert molding and coupled to the sleeve 130. Since the sleeve 130 is pressed into the steering shaft 40 and fixed to the steering shaft 40, the sleeve 130 is coupled to the gear 220 by insert molding, and the gear 220 is coupled to the rotor 210 by a fixing portion 240 described below, the steering shaft 40, the sleeve 130, the gear 220, and the rotor 210 may be axially fixed and rotatable together.

[0084] The fixing portion 140 may fix the rotor 210 to the gear 220 through or by means of a simple structure and a simple assembly process.

[0085] Fig.11 is another perspective view for illustrating the gear 220 according to an embodiment of the present disclosure, and Fig.12 is another perspective view for illustrating a rotor 210 and a gear 220 coupled to each other according to another embodiment of the present disclosure. Fig.13 It is along Fig. 9 A cross-sectional view taken along line BB'.

[0086] Reference Figures 10 to 13, the fixing portion 240 may include at least one first coupling portion 250 for fixing the rotor 210 to the gear 220 with respect to the axial direction and at least one second coupling portion 260 for fixing the rotor 210 to the gear 220 with respect to the rotation direction or the circumferential direction. A plurality of first coupling portions 250 and a plurality of second coupling portions 260 may be provided in such a manner as to be alternately arranged between the rotor 210 and the gear 220 along the circumferential direction. The first coupling portion 250 and the second coupling portion 260 may be provided in various numbers as long as the first coupling portion 250 and the second coupling portion 260 can stably fix the rotor 210 to the gear 220.

[0087] One or more first coupling parts 250 may be provided between the rotor 210 and the gear 220 to fix the rotor 210 to the gear 220 with respect to the axial direction. Each of the first coupling parts 250 may include a hook 251 provided in the gear 220 and a hook rib 252 provided in the rotor 210. The hook 251 is inserted into the hook rib 252 and coupled thereto.

[0088] The hook 251 may protrude outward from the outer peripheral surface of the gear 220 and may be caught by the hook groove 252b of the rotor 210, which will be described below. The hook 251 may be integrally injection-molded with the gear 220, and when the hook 251 is inserted into and coupled to the hook groove 252b, which will be described below, the upper end of the hook 251 may be in close contact with the downward surface of the hook groove 252b to firmly fix the rotor 210 to the gear 220. In addition, in order to stably maintain the hook 251 in a coupled state inside the hook rib 252, the upper end of the hook 251 may protrude at an angle corresponding to an angle perpendicular to the outer peripheral surface of the gear 220, thereby preventing the rotor 210 from falling off or disengaging from the gear 220 in the axial direction. The lower surface of the hook 251 can be set as a hook guide surface 253, which gradually decreases downward in height or thickness from the gear 220, and the hook guide surface is inclined or angled so that when the hook 251 enters the inner circumferential surface of the hook rib 252 (which will be described below) for assembling the rotor 210 and the gear 220, the hook 251 easily enters the inner circumferential surface of the hook rib 252 or is easily inserted into the inner circumferential surface of the hook rib 252.

[0089] The hook rib 252 may be provided in the rotor 210, and the hook 251 may be inserted into the hook rib 252 and interlocked with the hook rib 252 or caught by the hook rib 252. More specifically, the hook rib 252 may include a first base 252a and a hook groove 252b. The first base 252a may be bent and extended upward from the rotor 210, and face the outer peripheral surface of the gear 220. The hook groove 252b may penetrate the first base 252a or be recessed from the first base 252a in the radial direction. The hook 251 is inserted into the hook groove 252b and interlocked with the hook groove 252b or caught by the hook groove. The hook rib 252 may be made of, for example, but not limited to, a metal material like the rotor 210, and is configured to be elastically deformable or flexible to be assembled with and coupled to the hook 251. However, the hook rib 252 may be made of any suitable material that is elastically deformable or flexible.

[0090] The first base 252a may be generally in the shape of a plate bent and extended upward from the inner peripheral surface of the blade 212 on the body 211 of the rotor 210. In a state where the rotor 210 and the gear 220 are assembled together, the first base 252a may be positioned outside the gear 220, and thus, the inner surface of the first base 252a may face the outer peripheral surface of the gear 220. The hook groove 252b may penetrate the first base 252a or be recessed from the inner surface of the first base 252a in a radial direction, and the hook 251 may be inserted into the hook groove 252b and interlocked with or caught by the hook groove 252b. The hook 251 of the gear 220 may enter the inner circumferential surface of the first base 252a and move along the inner circumferential surface of the first base 252a, and then be inserted into the hook groove 252b from the inside of the rotor 210 toward the outside of the rotor 210, and the upper end of the hook 251 may be caught by the downward surface of the hook groove 252b, thereby fixing the rotor 210 to the gear 220 relative to the axial direction. More specifically, because the hook rib 252 is elastically deformable or flexible, when the rotor 210 and the gear 220 are assembled, the hook 251 may move toward the hook groove 252b while the hook rib 252 is pressed outward in the radial direction while the hook 251 is in close contact with the inner circumferential surface of the hook rib 252, and when the hook 251 is inserted into the hook groove 252b, the hook rib 252 may be restored to its original shape by elastic restoring force to fix the rotor 210 to the gear 220 relative to the axial direction. At the same time, Figures 10 to 13 An exemplary embodiment is shown in which the hook groove 252b penetrates the hook rib 252. However, the hook groove 252b may be recessed from the inner circumferential surface of the hook rib 252 in the radial direction, and thus, the hook 251 may be inserted into the hook groove 252b and interlocked with or coupled to the hook groove 252b.

[0091] One or more second coupling parts 260 may be positioned between the rotor 210 and the gear 220 to fix the rotor 210 to the gear 220 with respect to the rotation direction. Each of the second coupling parts 260 may include a support rib 261 protruding from the gear 220 and include a pair of press-fit ribs 262 provided in the rotor 210 and in close contact with both sides of the support rib 261 or the pair of support ribs 261.

[0092] The support rib 261 may protrude inwardly from the inner circumferential surface of the gear 220 in the radial direction. In addition, the support rib 261 may extend in the axial direction to be stably coupled to the press-fit rib 262. The pair of press-fit ribs 262 may be provided on the body 211 of the rotor 210 and positioned to or around both sides of the support rib 261 to be in close contact with and pressed to or support both side surfaces of the support rib 261, thereby limiting the movement of the press-fit rib 262 in the circumferential direction. Each of the press-fit ribs 262 may include a second base 262a that is bent and extended upward from the rotor 110 and includes a plurality of coupling protrusions 262b that protrude from the side surface of the second base 262a in the radial direction and are pressed to or support the side surface of the support rib 261.

[0093] The second base 262a may be generally in the shape of a plate extending upward from the inner peripheral surface of the blade 212 on the body 211 of the rotor 210. When the rotor 210 and the gear 220 are assembled, the second base 262a may be positioned inside the gear 220, and thus, the outward surface of the second base 262a may face the inner peripheral surface of the gear 220. When the rotor 210 is coupled to the gear 220, a pair of second bases 262a may be positioned to both sides of each support rib 261, and the coupling protrusions 262b protruding from the side surfaces of the second bases 262a may be in close contact with the side surfaces of the support ribs 261 and pressed to the side surfaces of the support ribs 261, thereby fixing the rotor 210 to the gear 220 with respect to the rotation direction.

[0094] The upward surface of each coupling protrusion 262b may include an inclined press-fit guide surface 262c. The press-fit guide surface 262c may be provided at the upward surface of the coupling protrusion 262b and may be inclined upward toward the side surface of the second base 262a. Therefore, the press-fit guide surface 262c may enable the support rib 261 to easily enter or be easily inserted between the pair of second bases 262a, and enable the coupling protrusion 262b to be easily pressed to the support rib 261 or support the support rib 261. In addition, the downward surface of the coupling protrusion 262b may have an angle corresponding to an angle perpendicular to the side surface of the second base 262a, thereby preventing the gear 220 from being disengaged or falling off from the rotor 210 in the axial direction.

[0095] Therefore, the rotor assembly of the torque sensor according to some embodiments of the present disclosure can firmly fix the rotor to the gear with a simple structure.

[0096] The rotor assembly of a torque sensor according to certain embodiments of the present disclosure can improve the durability and wear resistance of the torque sensor product.

[0097] The rotor assembly of the torque sensor according to various embodiments of the present disclosure can reduce the number of components of the rotor assembly.

[0098] The rotor assembly of the torque sensor according to certain embodiments of the present disclosure can simplify the manufacturing process of the rotor assembly.

[0099] The rotor assembly of the torque sensor according to some embodiments of the present disclosure can improve product productivity and reduce manufacturing costs.

[0100] This application is based on and claims the benefit of priority from Korean Patent Application No. 10-2023-0103153 filed in the Korean Intellectual Property Office on August 7, 2023, the disclosure of which is incorporated herein by reference in its entirety.

Claims

1. A rotor assembly, comprising: a rotor having a through hole formed in an axial direction so that the steering shaft is inserted into the through hole of the rotor; a gear having a generally annular shape and coupled to the rotor; as well as a fixing portion configured to fix the rotor to the gear, the fixing portion comprising: at least one first coupling portion configured to fix the rotor to the gear relative to the axial direction, the at least one first coupling portion comprising a hook groove and an elastically deformable or flexible hook bent from the rotor, the hook groove penetrating the gear in a radial direction or recessed from a surface of the gear so that the hook is inserted into the hook groove.

2. The rotor assembly according to claim 1, wherein: The hook comprises: a first base portion extending upward from the rotor and facing an inner peripheral surface of the gear; a bent portion bent from an end of the first base portion; and a locking portion extending downward from the bent portion and coupled to the hook groove, and Wherein, a lower end portion of the locking portion of the hook contacts an upward surface of the hook groove.

3. The rotor assembly of claim 1 , further comprising at least one second coupling portion configured to fix the rotor to the gear relative to a rotational direction, in, The at least one second coupling portion comprises: a support rib protruding inwardly from an inner peripheral surface of the gear; and a pair of press-fit ribs, the pair of press-fit ribs being disposed at the rotor, wherein the support rib is disposed between the pair of press-fit ribs, and Wherein, at least one of the pair of press-fit ribs comprises: a second base extending upward from the rotor; and One or more coupling protrusions protrude from a side surface of the second base portion in a circumferential direction and contact a side surface of the support rib.

4. The rotor assembly according to claim 1, wherein: The gear further includes a rotation support protruding outward from an outer peripheral surface of the gear, wherein at least a portion of the rotation support can contact the housing.

5. The rotor assembly according to claim 1, further comprising a sleeve having a substantially hollow shape and disposed in the gear to rotate together with the steering shaft, in, The sleeve has a metal material, and the gear has a plastic material.

6. A rotor assembly, comprising: a rotor having a through hole formed in an axial direction so that the steering shaft is inserted into the through hole of the rotor; a gear having a generally annular shape and coupled to the rotor; as well as a fixing portion configured to fix the rotor to the gear, the fixing portion comprising: At least one first coupling portion, the at least one first coupling portion being configured to fix the rotor to the gear relative to the axial direction, the at least one first coupling portion comprising a hook protruding outward from the outer periphery of the gear and an elastically deformable or flexible hook rib, the hook rib having a hook groove penetrating the rotor in a radial direction or recessed from the surface of the rotor, wherein the hook is inserted into the hook groove of the hook rib.

7. The rotor assembly according to claim 6, wherein: The hook rib comprises: a first base portion extending upward from the rotor and facing an outer peripheral surface of the gear; and the hook groove penetrating the first base portion in the radial direction or recessed from the surface of the first base portion, and Wherein, the upper end portion of the hook contacts the downward surface of the hook groove.

8. The rotor assembly of claim 6, further comprising at least one second coupling portion configured to fix the rotor to the gear relative to a rotational direction, in, The at least one second coupling portion comprises: a support rib protruding inwardly from an inner peripheral surface of the gear; and a pair of press-fit ribs, the pair of press-fit ribs being disposed at the rotor, wherein the support rib is disposed between the pair of press-fit ribs, and Wherein, at least one of the pair of press-fit ribs comprises: a second base extending upward from the rotor; and One or more coupling protrusions protrude from a side surface of the second base portion in a circumferential direction and contact a side surface of the support rib.

9. The rotor assembly according to claim 6, wherein: The gear further includes a rotation support protruding outward from an outer peripheral surface of the gear, wherein at least a portion of the rotation support can contact the housing.

10. The rotor assembly according to claim 6, further comprising a sleeve having a substantially hollow shape and disposed in the gear to rotate together with the steering shaft, in, The sleeve has a metal material, and the gear has a plastic material.

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