Bearing unit and roller assembly including the same

Abstract

The present invention relates to a bearing unit and a roller assembly including the same, and more specifically, to a bearing unit capable of adjusting the axial clearance between the inner ring and the outer ring of a bearing supporting the rotation axis of a roller to an appropriate state, and a roller assembly including the same. A bearing unit according to one embodiment of the present invention includes a bearing portion that rotatably supports a shaft and a piston portion that applies an external force to the bearing portion in the axial direction of the shaft. The bearing portion includes an inner ring coupled to the shaft and rotating together with the shaft, and an outer ring that surrounds the inner ring so that the inner ring is positioned on the inner side. The piston portion includes a first piston positioned on one side of the bearing portion and moving the outer ring by pushing it so that the axial clearance between the inner ring and the outer ring is removed when the inner ring moves in a direction that separates from the inner side of the outer ring, and a second piston positioned on the other side of the bearing portion and moving the outer ring by pushing it so that the inner ring separates from the inner side of the outer ring when the axial clearance is removed by the first piston. The direction in which the first piston pushes the outer ring and the direction in which the second piston pushes the outer ring may be opposite to each other.

Description

Technology Field

[0001] The present invention relates to a bearing unit and a roller assembly including the same, and more specifically, to a bearing unit capable of adjusting the axial clearance between the inner ring and the outer ring of a bearing supporting the rotation axis of a roller to an appropriate state, and a roller assembly including the same. Background Technology

[0003] Although secondary batteries have been applied in small-scale fields such as mobile devices and laptop computers, research directions have recently expanded to medium and large-scale fields, and they are widely used in fields requiring high voltage and large capacity, such as Energy Storage Systems (ESS) and Electric Vehicles (EV). Battery packs can be formed by packaging battery cells made of these secondary batteries.

[0004] In the manufacturing process of such secondary batteries, a roller assembly may be utilized, comprising rollers for rolling or conveying specific sheets, a shaft extending from the rollers, and a bearing supporting the shaft. For example, when manufacturing a dry electrode, powder fed between a pair of roller assemblies may be compressed and molded by the rollers to produce a sheet-shaped electrode. Alternatively, the sheet-shaped electrode fed between the pair of roller assemblies may be conveyed in the direction of rotation of the rollers.

[0005] Meanwhile, during the manufacturing process of secondary batteries, powders or electrodes are often heated to a predetermined temperature to be molded or transported. As a result, thermal deformation, particularly thermal expansion, may occur in the rollers in the axial direction due to heat. When thermal expansion occurs in the rollers, thermal stress may be applied to the bearings supporting the rollers, and such thermal stress can cause a decrease in bearing durability, increased fatigue, and a shortened lifespan.

[0006] In this case, if thermal expansion occurs in the roller, the components constituting the bearing may deviate from their rated positions, leading to a problem where the bearing clearance changes. Such changes in clearance can have a significant impact on electrodes with very small thicknesses.

[0007] In particular, there are cases where roller bearings must be used to support rollers, in which the internal rotating member has a cylindrical or truncated cone shape. However, when using bearings like roller bearings that cannot adequately support axial loads, the clearance between the inner and outer rings of the roller bearing increases or decreases beyond the set range due to the thermal expansion of the rollers. The clearance between the inner and outer rings of the roller bearing needs to be set within an appropriate range to distribute the load acting on the internal rotating member, optimize lubrication, and minimize noise and vibration. However, if this clearance increases beyond the set range, problems have arisen where excessive noise and vibration occur in the rollers, precision is reduced, and variations in electrode thickness occur. Alternatively, if this clearance decreases beyond the set range, excessive load is applied to the bearing, which can lead to reduced bearing durability and a shortened lifespan. The problem to be solved

[0009] The present invention has been devised to solve the above-mentioned problem, and the objective of the present invention is to relate to a bearing unit capable of adjusting the axial clearance between the inner ring and the outer ring of a bearing supporting the rotation axis of a roller to an appropriate state, and a roller assembly including the same.

[0010] In addition, the present invention relates to a bearing unit capable of improving the durability or lifespan of a bearing supporting a roller, and a roller assembly including the same.

[0011] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art to which the present invention pertains from the description below. means of solving the problem

[0013] To solve the above-mentioned problem, the bearing unit according to the present invention comprises a bearing portion that rotatably supports the shaft and a piston portion that applies an external force to the bearing portion in the axial direction of the shaft. The bearing portion comprises an inner ring coupled to the shaft and rotating together with the shaft, and an outer ring that surrounds the inner ring so that the inner ring is positioned on the inner side. The piston portion comprises a first piston positioned on one side of the bearing portion and moving the outer ring by pushing it so that the axial clearance between the inner ring and the outer ring is removed when the inner ring moves in a direction that separates from the inner side of the outer ring, and a second piston positioned on the other side of the bearing portion and moving the outer ring by pushing it so that the inner ring separates from the inner side of the outer ring when the axial clearance is removed by the first piston. The direction in which the first piston pushes the outer ring and the direction in which the second piston pushes the outer ring may be opposite to each other.

[0014] When the shaft undergoes thermal expansion, the inner ring may move in the axial direction of the shaft.

[0015] A bearing unit according to the present invention further includes a control unit for controlling the driving of the piston portion, and the bearing portion includes a rotating member disposed between the inner ring and the outer ring and supporting the inner ring so as to be rotatable relative to the outer ring, and the control unit can determine that the axial clearance is removed when the inner ring and the outer ring come into contact with the rotating member.

[0016] The bearing unit according to the present invention further includes a control unit for controlling the driving of the piston portion and a temperature sensor for measuring the temperature of the shaft, wherein if the temperature of the shaft is above a preset temperature, the control unit determines that the inner ring has moved in a direction of detachment from the inner side of the outer ring and drives the first piston to push the outer ring.

[0017] The bearing unit according to the present invention further comprises a control unit for controlling the driving of the piston unit and a temperature sensor for measuring the temperature of different regions of the shaft, wherein if a plurality of temperature values ​​measured by the temperature sensor are within a preset temperature range, the control unit determines that the inner ring has moved in a direction of detachment from the inner side of the outer ring and drives the first piston to push the outer ring.

[0018] The bearing unit according to the present invention further comprises a control unit for controlling the driving of the piston portion and a pressure sensor disposed on the first piston and measuring the pressure applied to the first piston, wherein if the pressure applied to the first piston is greater than or equal to a preset pressure, the control unit determines that the axial clearance between the inner ring and the outer ring has been eliminated and drives the second piston to push the outer ring.

[0019] The first piston moves the outer ring by a first distance, and the second piston moves the outer ring by a second distance, and the second distance may be smaller than the first distance.

[0020] The bearing unit according to the present invention further includes a control unit for controlling the driving of the piston unit and a distance sensor for detecting the second distance traveled by the outer ring, and the control unit can drive the second piston to push the outer ring until the second distance reaches a preset distance.

[0021] The bearing unit according to the present invention further includes a bearing housing that accommodates the bearing portion inside, and the outer surface of the outer ring can be inserted in close contact with the inner surface of the bearing housing.

[0022] The above external force may be greater than the frictional force between the outer ring and the bearing housing.

[0023] The above piston part can move while being guided by the above bearing housing.

[0024] The above piston portion may have a ring shape through which the shaft passes.

[0025] At least one of the first piston and the second piston comprises a piston member that reciprocates along the axial direction of the shaft and an adapter disposed at the end of the piston member facing the outer ring and moving together with the piston member, and when the piston member moves in a direction toward the outer ring, the adapter can apply an external force to the outer ring.

[0026] The above adapter may include a first adapter part that contacts and supports the outer ring, and a second adapter part that extends from the first adapter part toward the shaft and is spaced apart from the inner ring.

[0027] The second adapter part can form a step difference with the first adapter part.

[0028] The distance between the first adapter part and the shaft may be greater than the distance between the second adapter part and the shaft.

[0029] The above adapter may have a ring shape through which the shaft passes.

[0030] The above bearing part may be a tapered roller bearing.

[0031] The bearing portion comprises a first bearing and a second bearing arranged adjacent to each other, and the bearing unit according to the present invention may further include a distance adjustment portion arranged between the first bearing and the second bearing and adjusting the distance between the first bearing and the second bearing.

[0032] The distance adjustment part may have a ring shape through which the shaft passes.

[0033] To solve the above-mentioned problem, a roller assembly according to the present invention is a roller assembly for press-forming powder into a sheet-shaped electrode or for conveying a sheet-shaped electrode, and comprises a roller, a shaft extending from the roller, a bearing unit rotatably supporting the shaft, and a piston unit that applies an external force to the bearing unit in the axial direction of the shaft, wherein the bearing unit comprises an inner ring coupled to the shaft and rotating together with the shaft, and an outer ring surrounding the inner ring so that the inner ring is positioned on the inner side, and wherein the piston unit comprises a first piston disposed on one side of the bearing unit and which pushes and moves the outer ring so that the axial clearance between the inner ring and the outer ring is removed when the inner ring moves in a direction that separates from the inner side of the outer ring, and a second piston disposed on the other side of the bearing unit and which pushes and moves the outer ring so that the inner ring separates from the inner side of the outer ring when the axial clearance is removed by the first piston, and wherein the direction in which the first piston pushes the outer ring and the The direction in which the second piston pushes the outer ring may be opposite to each other. Effects of the invention

[0035] The bearing unit according to the present invention and the roller assembly including the same have the effect of being able to adjust the axial clearance between the inner ring and the outer ring of a bearing supporting the rotation axis of a roller to an appropriate state.

[0036] In addition, the present invention has the effect of improving the durability or lifespan of a bearing supporting a roller.

[0037] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the attached drawings. Brief explanation of the drawing

[0039] FIG. 1 is a perspective view of a roller assembly according to the present invention. Figure 2 is a cross-sectional view according to 1-1 of Figure 1. FIG. 3 is a perspective view of a bearing part according to the present invention. Figure 4 is a magnified view of part A of Figure 2. Figure 5 is a magnified view of part B of Figure 4. Figure 6 is a diagram showing the state in which the inner ring has moved in Figure 5. Figure 7 is a diagram showing the state in which the first piston in Figure 6 pushes the outer ring to eliminate the axial clearance between the inner ring and the outer ring. FIG. 8 is a diagram showing the state in which the second piston in FIG. 7 pushes the outer ring to create an appropriate axial clearance between the inner ring and the outer ring. FIG. 9 is a block diagram showing the control configuration of a roller assembly according to the present invention. Specific details for implementing the invention

[0040] Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.

[0041] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification.

[0042] Furthermore, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0044] FIG. 1 is a perspective view of a roller assembly according to the present invention, and FIG. 2 is a cross-sectional view according to 1-1 of FIG. 1.

[0045] Referring to FIGS. 1 and 2, a roller assembly (10) according to the present invention can be used to manufacture an electrode for a secondary battery and may include a roller (100), a shaft (200), and a bearing unit (300).

[0046] Although not shown in the drawing, a pair of roller assemblies (10) may be provided and may be arranged side by side to press powder into a sheet-shaped electrode or to transport the sheet-shaped electrode.

[0047] At this time, a predetermined space (hereinafter referred to as a gap) may be formed between a pair of roller assemblies (10) arranged side by side. Additionally, the rollers (100) of the pair of roller assemblies (10) may rotate in opposite directions to each other.

[0048] Powder that serves as a raw material for the electrode may be introduced into the gap. The powder is compressed by a pair of roller assemblies (10), and a sheet-shaped electrode may be manufactured. Here, the powder may be a slurry mixed with an electrode active material, a binder, a conductive material, etc.

[0049] A sheet-shaped electrode, which is the object to be transported, may be inserted into the gap. At this time, when the roller (100) of the roller assembly (10) rotates, both sides of the sheet-shaped electrode are respectively in close contact with the outer surface of a pair of rollers (100), and can be transported in a specific direction by friction with the roller (100).

[0050] Hereinafter, a roller assembly (10) according to the present invention will be described in detail.

[0051] The roller assembly (10) according to the present invention may include a roller (100). The roller (100) may have a cylindrical shape that is elongated in the front-rear direction (X-axis direction). At this time, the direction in which the roller (100) is arranged is not particularly limited.

[0052] Referring to FIG. 1, in the present invention, the central axis passing through the center along the longitudinal direction (X-axis direction) of the roller (100) may coincide with the rotation axis (hereinafter referred to as 'axis (C)') which is the center of rotation of the roller (100). That is, the roller (100) may rotate around the central axis. However, it is not limited thereto, and the axis (C) of the roller (100) may shift parallel to the central axis, so that the roller (100) may rotate eccentrically. For convenience of explanation, the central axis of the roller (100) and the axis (C) are described as coinciding below.

[0053] Meanwhile, the roller assembly (10) may include a heating unit (110). The heating unit (110) can apply heat to the roller (100). By doing so, the heating unit (110) can heat the powder formed by compression by the roller (100) or the sheet-shaped electrode conveyed by the roller (100) to a predetermined temperature or maintain the temperature within a specific range.

[0054] At this time, the heating unit (110) may be a heating device provided inside the roller (100). Alternatively, the heating unit (110) may be a fluid path provided inside the roller (100). High-temperature fluid may flow in the fluid path. However, the structure or type of the heating unit (110) is not particularly limited as long as it can apply heat to the roller (100).

[0055] The roller assembly (10) may include a shaft (200). The shaft (200) may extend from the roller (100). The shaft (200) may extend in an axial direction (X-axis direction) (hereinafter referred to as the axis (C) direction of the shaft (200)). The shaft (200) may be configured as a pair and provided on each side of the roller (100) in the longitudinal direction (X-axis direction).

[0056] The shaft (200) can transmit driving force to the roller (100) to rotate the roller (100). To this end, one side of the shaft (200) may be operatively connected to an actuator (not shown). Meanwhile, the shaft (200) and the roller (100) may share the same central axis, and accordingly, the central axis of the shaft (200) coincides with the axis (C), so that the shaft (200) can also rotate around the central axis. Therefore, the roller (100) and the shaft (200) can rotate concentrically together.

[0057] The roller assembly (10) according to the present invention may include a bearing unit (300).

[0058] The bearing unit (300) can be coupled to the shaft (200). Specifically, the bearing unit (300) can indirectly support the roller (100) by rotatably supporting the shaft (200).

[0059] The bearing unit (300) may be configured as a pair in a single roller assembly (10). A pair of bearing units (300) may each support a pair of shafts (200). Hereinafter, for convenience of explanation, one bearing unit (300) will be described.

[0060] The bearing unit (300) according to the present invention may include a bearing housing (310).

[0061] The bearing housing (310) forms the overall exterior of the bearing unit (300) and can accommodate the remaining components of the bearing unit (300) excluding the bearing housing (310) inside.

[0062] The bearing housing (310) may include a housing portion (311), a sealing portion (312), and a sealing cover portion (313).

[0063] The housing portion (311) may be manufactured from a material having a certain rigidity, such as metal or plastic. The housing portion (311) may surround the shaft (200) in the circumferential direction of the axis (C). The housing portion (311) may have a certain length in the direction extending along the axis (C) (X-axis direction).

[0064] As a result, a predetermined internal space may be formed between the inner side of the housing portion (311) and the outer surface of the shaft (200), and the remaining components of the bearing unit (300), excluding the bearing housing (310), may be accommodated in the internal space. Through this, the housing portion (311) can protect the remaining components of the bearing unit (300), excluding the bearing housing (310), from external impact or contamination.

[0065] Meanwhile, a certain fluid may be contained in the internal space of the housing part (311). For example, a lubricating fluid for the smooth operation of the bearing part (320, 1320) may be contained in the internal space. Therefore, the internal space needs to be isolated from the outside so that the fluid does not leak.

[0066] The sealing portion (312) can isolate the internal space from the outside, thereby preventing the fluid in the internal space from leaking out. That is, the sealing portion (312) may be a sealing member for isolating the internal space from the outside. For example, the sealing portion (312) may be an O-ring made of rubber or plastic, or a gasket made of an elastic material such as rubber or silicone. However, as long as the fluid in the internal space is not leaked out, the shape or material of the sealing portion (312) is not particularly limited.

[0067] The sealing portion (312) may be composed of a pair. A pair of sealing portions (312) may each be provided on both sides in the longitudinal direction (X-axis direction) of the housing portion (311). The sealing portion (312) may be formed in close contact with the outer surface of the shaft (200) or the roller (100). The sealing portion (312) can prevent fluid in the internal space from leaking to both sides in the longitudinal direction (X-axis direction) of the housing portion (311).

[0068] The sealing cover portion (313) can fix the position of the sealing portion (312) and prevent the sealing portion (312) from deviating from its proper position. The sealing cover portion (313) may have a socket structure into which the sealing portion (312) can be mounted or installed. The sealing cover portion (313) may be composed of a pair. A pair of sealing cover portions (313) can each fix a pair of sealing portions (312). The structure of the sealing cover portion (313) is not particularly limited as long as it can fix the sealing portion (312).

[0069] FIG. 3 is a perspective view of a bearing portion according to the present invention, FIG. 4 is a magnified view of portion A of FIG. 2, FIG. 5 is a magnified view of portion B of FIG. 4, FIG. 6 is a drawing showing the state in which the inner ring has moved in FIG. 5, FIG. 7 is a drawing showing the state in FIG. 6 in which the first piston pushes the outer ring to eliminate the axial clearance between the inner ring and the outer ring, FIG. 8 is a drawing showing the state in FIG. 7 in which the second piston pushes the outer ring to create an appropriate axial clearance between the inner ring and the outer ring.

[0070] Referring to FIGS. 3 to 8, the bearing unit (300) according to the present invention may further include a bearing portion (320, 1320) and a piston portion (330).

[0071] The bearing portion (320, 1320) is configured to rotatably support the shaft (200) and can be accommodated in the internal space of the housing portion (311) of the bearing housing (310). At this time, when the roller (100) of a pair of roller assemblies (10) rolls or conveys a specific sheet, the load acting in the radial direction becomes greater than the axial direction on the bearing portion (320, 1320). Therefore, the bearing portion (320, 1320) may be a bearing that sufficiently supports the radial load even if it does not sufficiently support the axial load acting on the shaft (200). For example, the bearing portion (320, 1320) may be a tapered roller bearing in which the inner ring (321, 1321) is inserted into the outer ring (322, 1322). At this time, if the bearing portion (320, 1320) does not sufficiently support the axial load acting on the shaft (200), the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) may deviate from the appropriate state. This allows the axial (C) direction clearance to be set to the appropriate state by the piston portion (330) to be described later.

[0072] Meanwhile, the bearing unit (300) according to the present invention may be composed of one bearing part (first bearing (320) or second bearing (1320)) and a pair of piston parts (first piston (331) and second piston (332)) respectively disposed on both sides of the one bearing part (first bearing (320) or second bearing (1320)).

[0073] However, alternatively, the bearing unit (300) according to the present invention may be composed of a pair of bearing portions (320, 1320) and a pair of piston portions (first piston (331) and second piston (332)) respectively disposed on both sides of the pair of bearing portions (320, 1320) (see FIGS. 3 to 8). That is, the bearing portions (320, 1320) may be composed of a first bearing (320) and a second bearing (1320) disposed adjacent to each other, and the piston portion (330) may be composed of a first piston (331) and a second piston (332) respectively disposed on the outside of the first bearing (320) and the second bearing (1320). Specifically, the first piston (331) may be positioned on one side in the direction of the axis (C) of the shaft (200) from the first bearing (320), and the second piston (332) may be positioned on the other side in the direction of the axis (C) of the shaft (200) from the second bearing (1320).

[0074] At this time, a distance adjustment unit (340) may be disposed between the first bearing (320) and the second bearing (1320), but the first bearing (320) and the second bearing (1320) may come into contact with each other. When the first bearing (320) and the second bearing (1320) come into contact with each other, the outer ring (322) of the first bearing (320) and the outer ring (1322) of the second bearing (1320) may come into contact with each other. In this case, if an external force is applied to either the outer ring (322) of the first bearing (320) or the outer ring (1322) of the second bearing (1320), the external force may be transmitted to the other one.

[0075] Below, the bearing part (320, 1320) and the piston part (330) will be described respectively.

[0076] Referring to FIG. 3, the bearing portion (320, 1320) may include an inner ring (321, 1321), an outer ring (322, 1322), a rotating member (323, 1323), and a holder (324, 1324).

[0077] The inner ring (321, 1321) is coupled to the shaft (200) and can rotate together with the shaft (200). At this time, since the shaft (200) rotates around the axis (C), the inner ring (321, 1321) can also rotate around the axis (C) of the shaft (200).

[0078] The inner ring (321, 1321) is fixed to the shaft (200) and can rotate together with the rotation of the shaft (200). The inner ring (321, 1321) may be formed in a ring shape, and the shaft (200) may be fitted and fixed to the inner side (321c, 1321c) of the inner ring (321, 1321) surrounded by the inner circumferential surface (321a, 1321a) of the inner ring (321, 1321). The inner ring (321, 1321) may be directly fixed to the shaft (200) by means such as welding, but is not limited thereto and may be fixed through a separate member.

[0079] When the shaft (200) and / or roller (100) undergo thermal expansion (TE), the direction in which the thermal expansion (TE) occurs may be the axis (C) direction of the shaft (200). Accordingly, when the shaft (200) and / or roller (100) undergo thermal expansion (TE), the inner ring (321, 1321) may move together with the shaft (200) in the axis (C) direction of the shaft (200).

[0080] The outer ring (322, 1322) can wrap around the inner ring (321, 1321). Specifically, the inner surface (322a, 1322a) of the outer ring (322, 1322) can wrap around the outer surface (321b, 1321b) of the inner ring (321, 1321) in a spaced-away manner. To this end, the outer ring (322, 1322) can be formed in a ring shape, and the inner diameter of the outer ring (322, 1322) can be larger than the outer diameter of the inner ring (321, 1321).

[0081] An inner ring (321, 1321), a rotating member (323, 1323), and a holder (324, 1324) may be disposed on the inner side (322c, 1322c) of the outer ring (322, 1322). Specifically, a holder (324, 1324) may be disposed on the inner side (322c, 1322c) of the outer ring (322, 1322), and an inner ring (321, 1321) may be disposed on the inner side of the holder (324, 1324). At this time, the inner side (322c, 1322c) of the outer ring (322, 1322) may refer to a space enclosed by the inner circumferential surface (322a, 1322a) of the outer ring (322, 1322).

[0082] The outer ring (322, 1322) can be inserted in close contact with the housing portion (311) of the bearing housing (310). Here, being inserted in close contact means that the outer ring (322, 1322) is inserted when it is supported by the housing portion (311) to the extent that the outer surface (322b, 1322b) of the outer ring (322, 1322) comes into direct contact with the inner surface of the housing portion (311) and frictional force acts between them.

[0083] The outer ring (322, 1322) has its outer surface (322b, 1322b) supported by the housing portion (311) of the bearing housing (310) and may not be fixed to the inner ring (321, 1321). Therefore, even if the shaft (200) and the inner ring (321, 1321) rotate, the outer ring (322, 1322) may not rotate because it is supported by the housing portion (311).

[0084] As described above, when the shaft (200) and / or roller (100) undergo thermal expansion (TE), the inner ring (321, 1321) can move together with the shaft (200) in the direction of the shaft (200) axis (C). Here, since the outer ring (322, 1322) is fixed in a state of being tightly inserted into the bearing housing (310), when the shaft (200) and / or roller (100) undergo thermal expansion (TE) and the inner ring (321, 1321) moves, the inner ring (321, 1321) moves in a direction that separates from the inner side of the outer ring (322, 1322).

[0085] The rotating member (323, 1323) can support the inner ring (321, 1321) so as to be rotatable relative to the outer ring (322, 1322). The rotating member (323, 1323) is positioned between the inner ring (321, 1321) and the outer ring (322, 1322) and can indirectly connect the inner ring (321, 1321) and the outer ring (322, 1322). The rotating member (323, 1323) may have a cylindrical or truncated cone shape, but its shape is not particularly limited.

[0086] A holder (324, 1324) is positioned between an inner ring (321, 1321) and an outer ring (322, 1322) and can rotatably support a rotating member (323, 1323). A space for receiving the rotating member (323, 1323) may be provided in the holder (324, 1324), and the rotating member (323, 1323) received in the space may roll while in contact with the inner ring (321, 1321) and the outer ring (322, 1322), respectively.

[0087] As described above, the bearing portion (320, 1320) may have a rotating member (323, 1323) having a cylindrical or truncated cone shape, and an inner ring (321, 1321) may be inserted into an outer ring (322, 1322). Through this, the bearing portion (320, 1320) can sufficiently support the radial load acting on the shaft (200). However, it may not sufficiently support the axial load acting on the shaft (200). Therefore, if the shaft (200) moves in the axial (C) direction (X-axis direction) due to thermal expansion (TE) of the roller (100) and / or shaft (200), the inner ring (321, 1321) moves in a direction that deviates from the inner side of the outer ring (322, 1322), and the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) increases, or an excessive load is applied to the outer ring (322, 1322), which may cause problems.

[0088] Accordingly, the piston part (330) according to the present invention can appropriately adjust the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322).

[0089] The axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) may mean the degree to which the axial (C) direction separation between the inner ring (321, 1321) and the outer ring (322, 1322) deviates from a preset separation.

[0090] Specifically, FIG. 5 illustrates a state in which the axial (C) direction clearance is eliminated (a state in which the axial (C) direction clearance is zero) by having the inner ring (321, 1321), the rotating member (323, 1323), and the holder (324, 1324) coupled in a fixed position to the outer ring (322, 1322), FIG. 6 illustrates a state in which the shaft (200) and / or the roller (100) undergo thermal expansion (TE) so that the inner ring (321, 1321) moves by a first distance (D1) in the axial (C) direction, thereby creating an axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322).

[0091] Referring to FIG. 5, the state in which the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) is removed may mean a state in which the relative positional change between the inner ring (321, 1321) and the outer ring (322, 1322) is restricted.

[0092] As a specific example, the state in which the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) is eliminated may mean that when the bearing part (320, 1320) is a tapered roller bearing, the inner ring (321, 1321) and the outer ring (322, 1322) are in contact with the rotating member (323, 1323).

[0093] Alternatively, the state in which the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) is removed may mean a state in which the inner ring (321, 1321) and the outer ring (322, 1322) are coupled to each other in the correct position. At this time, the state in which the inner ring (321, 1321) and the outer ring (322, 1322) are coupled to each other in the correct position may mean a state in which both ends of the inner ring (321, 1321) in the axial (C) direction are positioned on the inner side (322c, 1322c) of the outer ring (322, 1322).

[0094] Referring to FIG. 6, the state in which an axial (C) direction clearance occurs between the inner ring (321, 1321) and the outer ring (322, 1322) may mean a state in which a relative position change between the inner ring (321, 1321) and the outer ring (322, 1322) is possible.

[0095] As a specific example, the state in which an axial (C) direction clearance occurs between the inner ring (321, 1321) and the outer ring (322, 1322) may mean that, when the bearing portion (320, 1320) is a tapered roller bearing, at least one of the inner ring (321, 1321) and the outer ring (322, 1322) is not in contact with the rotating member (323, 1323).

[0096] Alternatively, the state in which an axial (C) direction clearance occurs between the inner ring (321, 1321) and the outer ring (322, 1322) may be a state in which the inner ring (321, 1321) is separated from the outer ring (322, 1322) by a predetermined distance in the axial (C) direction from its original position. Here, the original position may mean a state in which the rotating member (323, 1323) is in contact with the inner ring (321, 1321) and the outer ring (322, 1322), as shown in FIG. 5.

[0097] Alternatively, a state in which an axial (C) direction clearance occurs between the inner ring (321, 1321) and the outer ring (322, 1322) may mean a state in which at least a part of the inner ring (321, 1321) is detached from the inner side (322c, 1322c) of the outer ring (322, 1322).

[0098] Alternatively, the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 132) may mean an axial (C) direction separation between the inner ring (321, 1321) and the outer ring (322, 1322). Alternatively, the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) may mean an axial (C) direction gap or clearance between the inner ring (321, 1321) and the outer ring (322, 1322). Therefore, a state in which the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) is eliminated may mean a state in which the axial (C) direction gap or play between the inner ring (321, 1321) and the outer ring (322, 1322) is eliminated. In other words, a state in which the clearance between the inner ring (321, 1321) and the outer ring (322, 1322) is zero may mean a state in which the axial (C) direction gap or play between the inner ring (321, 1321) and the outer ring (322, 1322) is zero. Additionally, the state in which an axial (C) direction clearance occurs between the inner ring (321, 1321) and the outer ring (322, 1322) may mean a state in which an axial (C) direction gap or play occurs between the inner ring (321, 1321) and the outer ring (322, 1322).

[0099] The piston part (330) according to the present invention can maintain an appropriate clearance necessary to operate the bearing unit (300) by removing an excessive axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) through the first piston (331) and then intentionally generating a small amount of axial (C) direction clearance through the second piston (332).

[0100] Meanwhile, referring to FIGS. 4 to 8, the piston part (330) according to the present invention is configured to apply an external force to the bearing part (320, 1320) in the direction of the axis (C) of the shaft (200), and may include a first piston (331) and a second piston (332).

[0101] The first piston (331) is positioned on one side of the bearing portion (320, 1320) and can move the outer ring (322, 1322) by pushing it in the direction of thermal expansion (TE) of the shaft (200) and / or roller (100).

[0102] Specifically, when the shaft (200) and / or roller (100) undergo thermal expansion (TE) and an axial (C) clearance occurs between the inner ring (321, 1321) and the outer ring (322, 1322), the first piston (331) can move the outer ring (322, 1322) by pushing it so that the axial (C) clearance is removed.

[0103] For example, when the shaft (200) and / or roller (100) undergo thermal expansion (TE) and the inner ring (321, 1321) and / or outer ring (322, 1322) are separated from the rotating member (323, 1323), the first piston (331) can move the outer ring (322, 1322) by pushing it so that the inner ring (321, 1321) and the outer ring (322, 1322) come into contact with the rotating member (323, 1322).

[0104] In another example, when the shaft (200) and / or roller (100) undergo thermal expansion (TE) and the inner ring (321, 1321) moves in a direction that moves away from the inner side (322c, 1322c) of the outer ring (322, 1322), the first piston (331) can push and move the outer ring (322, 1322) so that both ends of the inner ring (321, 1321) in the axial (C) direction are positioned on the inner side (322c, 1322c) of the outer ring (322, 1322).

[0105] The second piston (332) is positioned on the other side of the bearing portion (320, 1320), and when the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) is removed by the first piston (331), the outer ring (322, 1322) can be pushed and moved so that the inner ring (321, 1321) is disengaged from the inner side (322c, 1322c) of the outer ring (322, 1322).

[0106] For example, when the outer ring (322, 1322) is moved by the first piston (331) and the inner ring (321, 1321) and the outer ring (1322) come into contact with the rotating member (323, 1323), the second piston (332) can move the outer ring (322, 1322) by pushing it so that the inner ring (321, 1321) and / or the outer ring (322, 1322) are separated from the rotating member (323, 1323).

[0107] As another example, when the outer ring (322, 1322) is moved by the first piston (331) so that both ends of the inner ring (321, 1321) in the direction of the axis (C) are positioned on the inner side (322c, 1322c) of the outer ring (322, 1322), the second piston (332) can move the outer ring (322, 1322) by pushing it so that at least a part of the inner ring (321, 1321) is displaced from the inner side (322c, 1322c) of the outer ring (322, 1322).

[0108] At this time, the direction in which the first piston (331) pushes the outer ring (322, 1322) and the direction in which the second piston (332) pushes the outer ring (322, 1322) may be opposite. That is, when the first piston (331) removes the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322), the second piston (332) then pushes the outer ring (322, 1322) in a direction opposite to the direction in which the first piston (331) pushes, thereby creating a small amount of axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322).

[0109] Meanwhile, referring to FIGS. 4 to 8, the first piston (331) according to the present invention may include a first piston member (331a) and a first adapter (331b), and the second piston (332) may include a second piston member (332a) and a second adapter (332b). Hereinafter, the first piston member (331a) and the second piston member (332a) will be collectively referred to as piston members (331a, 332a), and the first adapter (331b) and the second adapter (332b) will be collectively referred to as adapters (331b, 332b).

[0110] The piston members (331a, 332a) can reciprocate along the axis (C) direction of the shaft (200). A servo valve (not shown) may be connected to one side of the piston members (331a, 332b), and the servo valve may generate a driving force to enable the piston members (331a, 332a) to reciprocate.

[0111] At this time, the first piston member (331a) and the piston member (332a) of the second piston (332) can move in the same direction. Specifically, when the first piston member (331a) moves to one side in the direction of the axis (C) of the shaft (200), the second piston member (332a) can move to one side in the direction of the axis (C) of the shaft (200). Through this, when either the first piston (331) or the second piston (332) pushes the outer ring (322, 1322), the other one can support the outer ring (322, 1322) from the opposite side.

[0112] The piston members (331a, 332a) can reciprocate while being guided by the bearing housing (310). Specifically, the piston members (331a, 332a) can be formed in a ring shape through which the shaft (200) passes, and a portion of the outer surface of the piston members (331a, 332a) can reciprocate along the axis (C) direction of the shaft (200) while being guided by the housing part (311) in a state where it is in contact with the inner surface of the housing part (311) of the bearing housing (310).

[0113] The adapter (331b, 332b) is positioned at the end of the piston member (331a, 332a) facing the outer ring (322, 1322) and can move together with the piston member (331a, 332a). The adapter (331b, 332b) can serve to apply an external force to the outer ring (322, 1322) when the piston member (331a, 332a) is driven. Specifically, the adapter (331b) of the first piston (331) can apply an external force to the outer ring (322) of the first bearing (320), and the adapter (332b) of the second piston (332) can apply an external force to the outer ring (1322) of the second bearing (1320).

[0114] When the piston member (331a, 332a) moves in a direction that approaches the outer ring (322, 1322), the adapter (331b, 332b) can apply an external force to the outer ring (322, 1322). At this time, the adapter (331b, 332b) may be formed in a ring shape through which the shaft (200) passes, but the specific shape is not particularly limited.

[0115] The adapter (331b, 332b) may include a first adapter part (331ba, 332ba) and a second adapter part (331bb, 332bb).

[0116] The first adapter part (331ba, 332ba) can support the outer ring (322, 1322) by contacting the outer ring (322, 1322).

[0117] The first adapter part (331ba, 332ba) may have a ring shape through which the shaft (200) passes. The first adapter part (331ba, 332ba) may have a predetermined thickness in the axis (C) direction (X-axis direction) of the shaft (200).

[0118] A portion of the first adapter part (331ba, 332ba) that contacts the outer ring (322, 1322) may be formed as a flat surface to stably support the outer ring (322, 1322). At this time, the flat surface of the outer ring (322, 1322) may be in a direction perpendicular to the axis (C) direction (X-axis direction) of the shaft (200) (Y-axis and Z-axis direction).

[0119] The second adapter portion (331bb, 332bb) extends from the first adapter portion (331ba, 332ba) toward the shaft (200) and may be spaced apart from the inner ring (321, 1321). The second adapter portion (331bb, 332bb) may have a ring shape through which the shaft (200) passes. The second adapter portion (331bb, 332bb) may have a predetermined thickness in the axis (C) direction (X-axis direction) of the shaft (200).

[0120] At least a portion of the second adapter portion (331bb, 332bb) may be positioned to face the inner ring (321, 1321). At this time, at least a portion of the second adapter portion (331bb, 332bb) facing the outer ring (322, 1322) may be positioned spaced apart from the inner ring (321, 1321). This configuration is intended to prevent the inner ring (321, 1321) of the first bearing (320) and the second adapter portion (331bb, 332bb) from interfering with each other during the process of adjusting the clearance value of the bearing unit (300).

[0121] The second adapter part (331bb, 332bb) may form a step with the first adapter part (331ba, 332ba). Of course, the second adapter part (331bb, 332bb) may also be formed at an angle with the first adapter part (331ba, 332ba).

[0122] The first adapter part (331ba, 332ba) and the second adapter part (331bb, 332bb) may be spaced apart from the shaft (200). This is to prevent the shaft (200) and the adapter (331b, 332b) from interfering with each other when the shaft (200) rotates around the axis (C). To this end, the adapter (331b, 332b) may be inserted in close contact with the housing part (311) of the bearing housing (310).

[0123] The distance between the first adapter part (331ba, 332ba) and the shaft (200) may be greater than the distance between the second adapter part (331bb, 332bb) and the shaft (200). Through this, the first adapter part (331ba, 332ba) does not come into contact with the inner ring (321, 1321), so the external force can be concentrated only on the outer ring (322, 1322).

[0124] As another example, the roller assembly (10) according to the present invention may change the shape of the piston portion (330) so that a part of the first piston (331) contacts the outer ring (322, 1322) of the first bearing (320) and the remaining part does not contact the inner ring (321, 1321) of the first bearing (320), and a part of the second piston (332) contacts the outer ring (322, 1322) of the second bearing (1320) and the remaining part does not contact the inner ring (321, 1321) of the second bearing (1320). In this case, since the piston portion (330) does not contact the inner ring (321, 1321), the rotation of the inner ring (321, 1321) may not be hindered. In this embodiment, even when the adapter (331b, 332b) is not provided, the piston part (330) can move the outer ring (322, 1322) by pushing it in the direction of the shaft axis (C) (X-axis direction).

[0125] Meanwhile, referring to FIGS. 4 to 8, the bearing unit (300) according to the present invention may further include a distance adjustment unit (340).

[0126] The distance adjustment unit (340) may include a first distance adjustment member (341), a second distance adjustment member (342), and a third distance adjustment member (343).

[0127] The first distance adjustment member (341) is positioned between a pair of bearing parts (320, 1320) and can adjust the distance between adjacent pairs of bearing parts (320, 1320). Specifically, the first distance adjustment member (341) is positioned between a pair of outer rings (322, 1322) and can adjust the distance between adjacent pairs of outer rings (322, 1322).

[0128] The first distance adjustment member (341) may have a ring or cylinder shape through which the shaft (200) passes. The diameter of the first distance adjustment member (341) may correspond to the outer ring (322, 1322) of the bearing portion (320, 1320). Here, "corresponds" means that the outer diameter of the first distance adjustment member (341) is the same as the outer diameter of the outer ring (322, 1322), and the inner diameter of the first distance adjustment member (341) is larger than or equal to the inner diameter of the outer ring (322, 1322). Thus, the first distance adjustment member (341) may not interfere with the rotation of the inner ring (321, 1321).

[0129] At this time, the first distance adjustment member (341) may have a predetermined length in the axis (C) direction (X-axis direction). Both sides of the length direction (X-axis direction) of the first distance adjustment member (341) may each come into contact with a pair of outer rings (322, 1322). The length of the first distance adjustment member (341) may function as the rated distance between the pair of outer rings (322, 1322).

[0130] Meanwhile, since the first distance adjustment member (341) is fitted onto the outer ring (322) of the first bearing (320) and the outer ring (1322) of the second bearing (1320), it can serve to transmit the external force to the other one when an external force is applied to either of the pair of outer rings (322, 1322). For example, when the first piston (331) applies an external force to the outer ring (322) of the first bearing (320) and pushes, the first distance adjustment member (341) can transmit the external force to the outer ring (1322) of the second bearing (1320). For another example, when the second piston (332) applies an external force to the outer ring (1322) of the second bearing (1320) and pushes, the first distance adjustment member (341) can transmit the external force to the outer ring (322) of the first bearing (320).

[0131] The second distance adjustment member (342) is positioned between a pair of bearing parts (320, 1320) to adjust the distance between adjacent pairs of bearing parts (320, 1320). Specifically, the second distance adjustment member (342) is positioned between a pair of inner rings (321, 1321) to adjust the distance between adjacent pairs of inner rings (321, 1321).

[0132] The second distance adjustment member (342) may have a ring or cylinder shape through which the shaft (200) passes. The diameter of the second distance adjustment member (342) may correspond to the inner ring (321, 1321) of the bearing portion (320, 1320). Here, "corresponds" means that the inner diameter of the second distance adjustment member (342) is the same as the inner diameter of the inner ring (321, 1321), and the outer diameter of the second distance adjustment member (342) is smaller than or equal to the outer diameter of the inner ring (321, 1321). Thus, the second distance adjustment member (342) can rotate together with the inner ring (321, 1321) when the inner ring rotates, without being obstructed by the outer ring (322, 1322).

[0133] At this time, the second distance adjustment member (342) may have a predetermined length in the axis (C) direction (X-axis direction). Both sides of the second distance adjustment member (342) in the length direction (X-axis direction) may each come into contact with a pair of inner rings (321, 1321). The length of the second distance adjustment member (342) may function as the rated distance between the pair of inner rings (321, 1321).

[0134] The third distance adjustment member (343) is positioned between the bearing portion (320, 1320) and the roller (100) to adjust the distance between the bearing portion (320, 1320) and the roller (100). Specifically, the third distance adjustment member (343) is positioned between the inner ring (321) of the first bearing (320) and the roller (100) to adjust the distance between the inner ring (321) and the roller (100).

[0135] The third distance adjustment member (343) may have a ring or cylinder shape through which the shaft (200) passes. At this time, the diameter of the third distance adjustment member (343) may correspond to the inner ring (321) of the first bearing (320).

[0136] Meanwhile, the roller (100) may have an outer diameter larger than that of the shaft (200), and a step may be provided between the roller (100) and the shaft (200). The diameter of the third distance adjustment member (343) may be smaller than the outer diameter of the roller (100). Through this, the third distance adjustment member (343) is configured to engage with the step, thereby restricting movement toward the roller (100) side (in the X-axis direction).

[0137] The third distance adjustment member (343) may have a predetermined length in the axis (C) direction (X-axis direction). Both sides of the third distance adjustment member (343) in the longitudinal direction (X-axis direction) may contact the inner ring (321) of the first bearing (320) and the step, respectively. Specifically, one side of the third distance adjustment member (343) may be fixed to the inner ring (321) of the first bearing (320) or the step. When the third distance adjustment member (343) is fixed to the inner ring (321) of the first bearing (320), the first distance adjustment member (343) may move together with the inner ring (321). The length of the third distance adjustment member (343) may function as the rated distance between the inner ring (321) of the first bearing (320) and the roller (100).

[0138] Meanwhile, the distance adjustment unit (340) may be composed of ring or cylinder-shaped members, but the shape or structure of the distance adjustment unit (340) is not particularly limited as long as it can set the distance between the two components.

[0139] FIG. 9 is a block diagram showing the control configuration of a roller assembly according to the present invention.

[0140] Referring to FIG. 9, the roller assembly (10) according to the present invention may include a control unit (350), a temperature sensor (360), a pressure sensor (370), and a distance sensor (380) to appropriately adjust the axial (C) direction clearance value between the inner ring (321, 1321) and the outer ring (322, 1322).

[0141] The control unit (350) can control the operation of the piston unit (330). Specifically, the control unit (350) can control the operation of the piston unit (330) in a direction in which the piston unit (330) reciprocates along the axis (C) of the shaft (200).

[0142] At least one servo valve (not shown) providing driving force may be connected to each of the first piston (331) and / or the second piston (332). Accordingly, the first piston (331) and / or the second piston (332) can move in the direction of the axis (C) of the shaft (200) by the driving force provided by the servo valve.

[0143] At this time, the first piston (331) and the second piston (332) can move in the same direction.

[0144] For example, when the first piston (331) moves to one side in the axial direction (C), which is the direction in which it pushes the outer ring (322), the second piston (332) can move to one side in the axial direction (C) while supporting the outer ring (1322) on the opposite side of the first piston (331). At this time, the length of the first piston (331) can be extended overall, and the length of the second piston (332) can be shortened overall.

[0145] As another example, when the second piston (332) moves to the other side in the axial (C) direction, which is the direction in which it pushes the outer ring (322), the second piston (332) can move to the other side in the axial (C) direction while supporting the outer ring (1322) on the opposite side of the first piston (331). That is, when the second piston (332) is extended overall, the first piston (331) can be shortened overall.

[0146] A temperature sensor (360) may be placed on the shaft (200) and / or roller (100) and may measure the temperature of the shaft (200) and / or roller (100).

[0147] At this time, the control unit (350) can determine whether there is thermal expansion (TE) of the shaft (200) and / or roller (100) based on the temperature measured by the temperature sensor (360).

[0148] For example, if the temperature measured by the temperature sensor (360) is above a preset temperature, the control unit (350) determines that thermal expansion (TE) of the shaft (200) and / or roller (100) has occurred and can drive the first piston (331). At this time, the preset temperature may be the temperature of the shaft (200) and / or roller (100) when the thermal expansion (TE) of the shaft (200) and / or roller (100) is completed. Additionally, the exact temperature value of the preset temperature may be experimentally determined based on the length, material, thickness, etc. of the shaft (200) and / or roller (100).

[0149] When the above thermal expansion (TE) occurs, the control unit (350) can determine that an axial (C) direction clearance has occurred between the inner ring (321, 1321) and the outer ring (322, 1322) as the inner ring (321, 1321) moves in a direction that separates from the inner side of the outer ring (322, 1322). Accordingly, the control unit (350) can drive the first piston (331) to push the outer ring (322, 1322) of the first bearing (320) in order to remove the axial (C) direction clearance.

[0150] As another example, at least one temperature sensor (360) may be provided to measure the temperature of different regions of the shaft (200). At this time, if the multiple temperature values ​​measured by the temperature sensor (360) are within a preset temperature range, the control unit (350) may determine that the inner ring (321, 1321) moves in a direction that deviates from the inner side (322c, 1322c) of the outer ring (322, 1322), thereby causing an axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322).

[0151] At this time, the preset temperature range may be within the approximate range of the temperature of the shaft (200) and / or roller (100) when the thermal expansion (TE) of the shaft (200) and / or roller (100) is completed. That is, if multiple temperatures measured in the different regions converge within the preset temperature range, it means that the overall temperature of the shaft (200) and / or roller (100) has risen to a similar temperature, which may mean that the thermal expansion (TE) due to heating of the shaft (200) and / or roller (100) is completed. At this time, the exact temperature range value of the preset temperature range may be experimentally determined according to the length, material, thickness, etc. of the shaft (200) and / or roller (100).

[0152] When the above thermal expansion (TE) occurs, the control unit (350) can determine that an axial (C) direction clearance has occurred between the inner ring (321, 1321) and the outer ring (322, 1322) as the inner ring (321, 1321) moves in a direction that separates from the inner side of the outer ring (322, 1322). Accordingly, the control unit (350) can drive the first piston (331) to push the outer ring (322, 1322) of the first bearing (320) in order to remove the axial (C) direction clearance.

[0153] The pressure sensor (370) can measure the pressure applied to the first piston (331). Here, the pressure sensor (370) may be positioned at the end of the first piston (331) facing the outer ring (322), or between the first piston member (331a) and the first adapter (331b).

[0154] At this time, the control unit (350) can determine whether the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) has been removed by the first piston (331) based on the pressure measured by the pressure sensor (370). Specifically, if the pressure measured by the pressure sensor (370) is greater than or equal to a preset pressure, or if a sudden change in pressure is detected by the pressure sensor (370), the control unit (350) can determine that the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) has been removed and drive the second piston (332). That is, when the above-mentioned axial (C) direction clearance is removed, the control unit (350) can drive the second piston (332) to push the outer ring (322, 1322) of the second bearing (1320) so that an appropriate axial (C) direction clearance is generated again between the inner ring (321, 1321) and the outer ring (322, 1322). At this time, the direction in which the second piston (332) pushes the outer ring (1322) may be opposite to the direction in which the first piston (331) pushes the outer ring (322). Additionally, with the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) removed, the rotating member (323, 1323) may be in contact with the inner ring (321, 132) and the outer ring (322, 1322), or the axial (C) direction ends of the inner ring (321, 1321) may be positioned on the inner side (322c, 1322c) of the outer ring (322, 1322).

[0155] A distance sensor (380) may be placed on the first piston (331) and / or the second piston (332). The distance sensor (380) placed on the first piston (331) may be the first distance sensor (381), and the distance sensor (380) placed on the second piston (332) may be the second distance sensor (382).

[0156] The distance sensor (380) can measure the distance traveled by the outer ring (1322) of the second bearing (1320) when the second piston (332) pushes and moves the outer ring (322, 1322) of the second bearing (1320) while the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) is removed. At this time, the first distance sensor (381) measures the distance traveled by the first piston (331), and the second distance sensor (382) measures the distance traveled by the second piston (332).

[0157] The control unit (350) can move the second piston (332) until the distance traveled by the outer ring (1322) of the second bearing (1320) reaches a preset distance, thereby pushing the outer ring (1322) of the second bearing (1320). At the same time, the control unit (350) can move the first piston (331) in the same direction as the movement direction of the second piston (332) to support the outer ring (322) of the first bearing (320). Through this, the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) can be set to an appropriate state.

[0158] Meanwhile, below, with reference to FIGS. 5 to 8, the process of the bearing unit (300) according to the present invention adjusting the clearance value to an appropriate state will be specifically explained.

[0159] The piston part (330) according to the present invention can set the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) to an appropriate state for the smooth operation of the bearing unit (300). That is, the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) caused by thermal expansion (TE) of the shaft (200) and / or roller (100) may cause problems in the normal operation of the bearing unit (300), but if the bearing unit (300) operates with the axial (C) direction clearance completely removed, scratching or damage between the components of the bearing unit (300) may occur. Therefore, the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322), which is finally set by the piston part (330), needs to be maintained in an appropriate state.

[0160] Specifically, FIG. 5 illustrates a state in which there is no axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322). The state in which there is no axial (C) direction clearance may be a state in which the first piston (331) and the second piston (332) are not operating, but it may also be a state in which the sum of the force of the first piston (331) pushing the outer ring (322, 1322) of the first bearing (320) and the force of the second piston (332) pushing the outer ring (322, 1322) of the second bearing (1320) is zero.

[0161] FIG. 6 illustrates a state (hereinafter referred to as the "first state") in which the shaft (200) and / or roller (100) of FIG. 5 undergoes thermal expansion (TE) and the inner ring (321, 1321) moves by a first distance (D1) in the axial (C) direction (X-axis direction). At this time, an excessive axial (C) direction clearance occurs between the inner ring (321, 1321) and the outer ring (322, 1322), so it is necessary to remove the excessive axial (C) direction clearance.

[0162] Meanwhile, if the temperature of the shaft (200) and / or roller (100) measured by the temperature sensor (360) is above a preset temperature, or if the temperature measured by the plurality of temperature sensors (360) is within a preset temperature range, the control unit (350) may determine that the bearing unit (300) is in the first state.

[0163] FIG. 7 illustrates a state (hereinafter referred to as the ‘second state’) in which the first piston (331) moves (M1) the outer ring (322, 1322) of the first bearing (320) by a first distance (D1) to remove the excessive axial (C) direction clearance. At this time, the first distance (D1) may refer to the difference between the axial (C) direction length (L2) of the first piston (331) in the second state and the axial (C) direction length (L1) of the first piston (331) in the first state.

[0164] Meanwhile, if the pressure applied to the first piston (331) measured by the pressure sensor (370) is greater than or equal to a preset pressure, or if a sudden change in pressure is detected by the pressure sensor (370), the control unit (350) may determine that the bearing unit (300) is in the second state.

[0165] Additionally, since a first distance adjustment member (341) is disposed between the outer ring (322) of the first bearing (320) and the outer ring (1322) of the second bearing (1320), when the first piston (331) applies a first external force to the outer ring (322) of the first bearing (320), the first distance adjustment member (341) can transmit the first external force to the outer ring (1322) of the second bearing (1320). At this time, the first external force may be greater than the frictional force acting between the outer ring (322) of the first bearing (320) and the housing part (311) and the frictional force acting between the outer ring (1322) of the second bearing (1320) and the housing part (311).

[0166] FIG. 8 illustrates a state (hereinafter referred to as the ‘third state’) in which the second piston (332) moves (M2) the outer ring (1322) of the second bearing (1320) by a second distance (D2) in order to intentionally create an axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322). At this time, the second distance (D2) may mean the difference between the length (L2) of the first piston (331) in the second state and the length (L3) of the first piston (331) in the third state.

[0167] At this time, the second distance (D2) may be smaller than the first distance (D1). Since the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) that occurs due to the thermal expansion (TE) of the shaft (200) and / or the roller (100) needs to be set to an appropriate state, the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) that is finally set by the piston part (330) is not zero, but may be set smaller than the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) that occurs due to the thermal expansion (TE) of the shaft (200) and / or the roller (100). Accordingly, when the second piston (332) moves the outer ring (1322) of the second bearing (1320) by a second distance (D2) as in the third state above, the axial (C) direction clearance between the inner ring (321, 1321) and the outer ring (322, 1322) can be set to an appropriate state.

[0168] Meanwhile, the control unit (350) can move the second piston (332) to push the outer ring (1322) of the second bearing (1320) until the second distance (D2) measured by the distance sensor (380) reaches a preset distance, and can move the first piston (331) to support the outer ring (322) of the first bearing (320) from the opposite side. At this time, the first piston (331) and the second piston (332) can move in the same direction. In addition, the speed at which the second piston (332) moves and the speed at which the first piston (331) moves can correspond to each other.

[0169] Additionally, since a first distance adjustment member (341) is disposed between the outer ring (322) of the first bearing (320) and the outer ring (1322) of the second bearing (1320), when the second piston (332) applies a second external force to the outer ring (1322) of the second bearing (1320), the first distance adjustment member (341) can transmit the second external force to the outer ring (322) of the first bearing (320). At this time, the second external force may be greater than the frictional force acting between the outer ring (1322) of the second bearing (1320) and the housing part (311) and the frictional force acting between the outer ring (322) of the first bearing (320) and the housing part (311).

[0171] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0173] 10: Roller assembly 100: Roller 110: Heating unit 200: Shaft 300: Bearing unit 310: Bearing housing 320, 1320: Bearing section 330: Piston part 340: Distance adjustment unit 350: Control unit 360: Temperature sensor 370: Pressure sensor 380: Distance sensor

Claims

Claim 1 A bearing unit comprising: a bearing portion that rotatably supports a shaft; and a piston portion that applies an external force to the bearing portion in the axial direction of the shaft, wherein the bearing portion comprises: an inner ring coupled to the shaft and rotating together with the shaft; and an outer ring that surrounds the inner ring so that the inner ring is positioned on the inner side, wherein the piston portion comprises: a first piston disposed on one side of the bearing portion and moving the outer ring by pushing it so that the axial clearance between the inner ring and the outer ring is removed when the inner ring moves in a direction that causes the inner ring to detach from the inner side of the outer ring; and a second piston disposed on the other side of the bearing portion and moving the outer ring by pushing it so that the inner ring detaches from the inner side of the outer ring when the axial clearance is removed by the first piston, wherein the direction in which the first piston pushes the outer ring and the direction in which the second piston pushes the outer ring are opposite to each other. Claim 2 In claim 1, when the shaft undergoes thermal expansion, the inner ring is a bearing unit that moves in the axial direction of the shaft. Claim 3 A bearing unit according to claim 1, further comprising a control unit for controlling the drive of the piston portion, wherein the bearing portion comprises a rotating member disposed between the inner ring and the outer ring and supporting the inner ring so as to be rotatable relative to the outer ring, and wherein the control unit determines that the axial clearance is removed when the inner ring and the outer ring come into contact with the rotating member. Claim 4 A bearing unit according to claim 1, further comprising: a control unit for controlling the driving of the piston part; and a temperature sensor for measuring the temperature of the shaft, wherein the control unit determines that the inner ring has moved in a direction of detachment from the inner side of the outer ring when the temperature of the shaft is above a preset temperature, and drives the first piston to push the outer ring. Claim 5 A bearing unit according to claim 1, further comprising: a control unit for controlling the driving of the piston part; and a temperature sensor for measuring the temperature of different regions of the shaft, wherein the control unit determines that the inner ring has moved in a direction of detachment from the inner side of the outer ring when a plurality of temperature values ​​measured by the temperature sensor are within a preset temperature range, and drives the first piston to push the outer ring. Claim 6 A bearing unit according to claim 1, further comprising: a control unit for controlling the driving of the piston portion; and a pressure sensor disposed on the first piston and measuring the pressure applied to the first piston, wherein the control unit determines that the axial clearance between the inner ring and the outer ring is eliminated when the pressure applied to the first piston is greater than or equal to a preset pressure, and drives the second piston to push the outer ring. Claim 7 In claim 1, the first piston moves the outer ring by a first distance, the second piston moves the outer ring by a second distance, and the second distance is a bearing unit smaller than the first distance. Claim 8 In claim 7, the bearing unit further comprises a control unit for controlling the driving of the piston part; and a distance sensor for detecting the second distance traveled by the outer ring, wherein the control unit drives the second piston to push the outer ring until the second distance reaches a preset distance. Claim 9 A bearing unit according to claim 1, further comprising a bearing housing that accommodates the bearing portion therein, wherein the outer surface of the outer ring is inserted in close contact with the inner surface of the bearing housing. Claim 10 In claim 9, the above external force is greater than the frictional force between the outer ring and the bearing housing in the bearing unit. Claim 11 In claim 9, the piston part is a bearing unit that moves while being guided by the bearing housing. Claim 12 A bearing unit according to claim 1, wherein at least one of the first piston and the second piston comprises a piston member that reciprocates along the axial direction of the shaft; and an adapter disposed at the end of the piston member facing the outer ring and moving together with the piston member, wherein when the piston member moves in a direction toward the outer ring, the adapter applies an external force to the outer ring. Claim 13 In claim 12, the adapter comprises: a first adapter portion that contacts and supports the outer ring; and a second adapter portion that extends from the first adapter portion toward the shaft and is spaced apart from the inner ring, forming a bearing unit. Claim 14 In paragraph 13, the second adapter part is a bearing unit that forms a step with the first adapter part. Claim 15 In paragraph 13, the distance between the first adapter part and the shaft is greater than the distance between the second adapter part and the shaft, in the bearing unit. Claim 16 In claim 1, the bearing portion is a bearing unit that is a tapered roller bearing. Claim 17 A bearing unit according to claim 1, wherein the bearing portion comprises a first bearing and a second bearing arranged adjacent to each other, and further comprises a distance adjustment portion arranged between the first bearing and the second bearing and adjusting the distance between the first bearing and the second bearing. Claim 18 A roller assembly for press-forming powder into a sheet-shaped electrode or for conveying a sheet-shaped electrode, comprising: a roller; a shaft extending from the roller; and a bearing unit comprising a bearing portion rotatably supporting the shaft and a piston portion applying an external force to the bearing portion in the axial direction of the shaft, wherein the bearing portion comprises: an inner ring coupled to the shaft and rotating together with the shaft; and an outer ring surrounding the inner ring so that the inner ring is positioned on the inside; and wherein the piston portion comprises a first piston disposed on one side of the bearing portion and which pushes and moves the outer ring so as to eliminate the axial clearance between the inner ring and the outer ring when the inner ring moves in a direction that separates from the inside of the outer ring. A roller assembly comprising a second piston disposed on the other side of the bearing portion and which pushes and moves the outer ring so that the inner ring is disengaged from the inner side of the outer ring when the axial clearance is removed by the first piston, wherein the direction in which the first piston pushes the outer ring and the direction in which the second piston pushes the outer ring are opposite to each other.

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