Cushion pad for steel wire raceway bearing and manufacturing method thereof

Abstract

The present invention provides a cushion pad for a steel wire raceway bearing, the steel wire raceway bearing comprising a housing and a steel wire, and the cushion pad being disposed between the housing and the steel wire to partially surround the steel wire; wherein the cushion pad includes reinforcing fiber threads embedded inside the cushion pad in a circumferential direction and connected to the cushion pad, the reinforcing fiber threads having a lower elongation and a higher tensile strength with respect to the cushion pad. The invention also provides a method for manufacturing the cushion pad. The method comprises the following steps: step 1, pretreating the reinforcing fiber lines; 2, reinforcing fiber lines are introduced into an extrusion head used for extruding the cushion pad to reach the extrusion position corresponding to the embedding position of the reinforcing fiber lines in the cushion pad; and 3, co-extruding the buffer pad and the reinforced fiber lines through an extrusion head. According to the invention, after the reinforcing fiber lines are connected with the cushion pad, various deformations caused by the factors can be hindered under the extrusion curing process and the storage condition, so that the size of the cushion pad is stable.

Description

Technical Field

[0001] The present invention provides a buffer pad for a wire race bearing and a manufacturing method thereof. Background Art

[0002] A wire race bearing is a bearing with a unique structure and has a wide range of application scenarios. A wire race bearing generally includes rolling elements, wires in contact with the rolling elements and having raceway surfaces, a housing for accommodating the rolling elements and the wires, etc. The wires are generally distributed at diagonal positions of the rolling elements and may include, for example, a pair of wires arranged along a set of diagonal positions or two pairs of wires arranged along two sets of diagonal positions. Usually, the wires are placed at corresponding recesses of the housing, and the recesses are formed by walls perpendicular to each other. Usually, in a wire race bearing, the buffer pad provided between the recess and the wire is made of an elastomer.

[0003] Wire race bearings, especially wire race ball bearings, are widely used in medical imaging equipment such as CT machines. However, the vibration of wire race bearings is a pain point in the application of CT machines. In the prior art, an elastomer buffer pad is usually used to reduce vibration, but the aging of the elastomer is closely related to the bearing performance. Especially when the buffer pad is squeezed for a long time, it is very likely to lose its elasticity and cannot recover. Secondly, the buffer pad is usually immersed in the grease used to lubricate the rolling elements, wires, etc., and the volume and hardness of the buffer pad will change. The changes in the physical and chemical properties of the buffer pad may lead to changes in the bearing clearance. Moreover, the buffer pad will also shrink in volume during storage, making the size of the buffer pad unstable.

[0004] Therefore, there is a need in the art for a buffer pad that can overcome the above problems. Summary of the Invention

[0005] In view of the problems and needs mentioned above, the present disclosure provides a novel technical solution, which solves the above problems and brings other technical effects due to the following technical features.

[0006] The present invention provides a buffer pad for a wire race bearing, the wire race bearing including a housing and a wire, and the buffer pad being disposed between the housing and the wire to partially surround the wire; wherein, the buffer pad includes a reinforcing fiber line embedded in the buffer pad along the circumferential direction and connected to the buffer pad, and the reinforcing fiber line has a lower elongation rate and a higher tensile strength relative to the buffer pad.

[0007] The present invention also provides a method for manufacturing the buffer pad as described above, including: Step 1: pretreat the reinforcing fiber line; Step 2: introduce the reinforcing fiber line into an extrusion head for extruding the buffer pad to reach an extrusion position corresponding to the embedding position of the reinforcing fiber line in the buffer pad; Step 3: co-extrude the buffer pad and the reinforcing fiber line through the extrusion head.

[0008] According to the present invention, when the reinforcing fiber line is connected to the buffer pad, various deformations caused by the above factors will be hindered during the extrusion curing process and storage conditions, making the size of the buffer pad stable. Thus, in the final assembly process of the product, based on the correct cutting length and high dimensional stability, the assembly difficulty can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic cross-sectional view of a wire race bearing;

[0010] Figure 2 It is a schematic cross-sectional view of a buffer pad according to a preferred embodiment of the present invention;

[0011] Figure 3 It is a schematic diagram of the manufacturing process of a buffer pad according to a preferred embodiment of the present invention;

[0012] Figure 4 It is a schematic flow chart of a method for manufacturing a buffer pad according to a preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0013] In order to make the objectives, technical solutions, and advantages of the technical solutions of the present disclosure clearer, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the specific embodiments of the present disclosure. The same reference numerals in the drawings represent the same components. It should be noted that the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0014] Compared with the embodiments shown in the drawings, the feasible implementation solutions within the scope of protection of the present disclosure may have fewer components, have other components not shown in the drawings, different components, differently arranged components, or differently connected components, etc. In addition, two or more components in the drawings may be implemented in a single component, or a single component shown in the drawings may be implemented as multiple separate components.

[0015] Unless otherwise defined, technical terms or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the art to which this disclosure pertains. The terms "first", "second" and similar terms used in the specification and claims of this patent application of the disclosure do not denote any order, quantity or importance, but are only used to distinguish different components. When the number of components is not specified, the number of components may be one or more; similarly, terms such as "a", "the", "said" and the like do not necessarily denote a quantity limitation. Terms such as "comprising" or "including" mean that the elements or objects appearing before this term cover the elements or objects listed after this term and their equivalents, without excluding other elements or objects. Terms such as "installed", "set", "connected" or "coupled" are not limited to physical or mechanical installation, setting or connection, but may include electrical installation, setting or connection, whether direct or indirect. Terms such as "upper", "lower", "left" and "right" are only used to indicate the relative orientation relationship during the use of the device or the orientation relationship shown in the drawings. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0016] For ease of description, in this document, the direction of the axis of rotation of the bearing is referred to as the axial direction, and the direction perpendicular to this axial direction is referred to as the radial direction. The terms "inner / towards the inside" mean along the direction towards the inside of the bearing. Conversely, the terms "outer / towards the outside" mean towards the outside of the bearing. Additionally, in different embodiments, the same reference numerals are used to refer to components having the same or similar structures and functions.

[0017] As previously mentioned, a wire race bearing generally includes: a housing, wires, and rolling elements. In different wire race bearings, the structures and forms of the housing, wires, and rolling elements are also different.

[0018] Figure 1 A specific wire race bearing is shown, including a housing 1, wires 2, cushion pads 3, rolling elements 4, etc. The housing 1 can further include a first outer ring housing 11, a second outer ring housing 12, and an inner ring housing 13. The rolling elements 4 are arranged in two rows, and the form of the rolling elements is balls. Each row of rolling elements 4 is supported by the raceway surfaces of the wires 2 arranged diagonally. The wires 2 are accommodated in the recesses of the corresponding housing. Figure 1 Two recesses 130 of the inner ring housing 13 are marked, and the wires 2 in the recesses 10 are in direct contact with the recess walls. The first and second outer ring housings 11, 12 respectively include recesses 110, 120, and the cushion pads 3 are respectively arranged in the recesses 110, 120, so that the cushion pads 3 are located between the housing and the wires to partially surround the wires 2.

[0019] According to the present invention, referring to Figure 2, the buffer pad 3 includes reinforcing fiber lines 4 embedded inside the buffer pad 3 along the circumferential direction and connected to the buffer pad 3 (as Figure 2 shown by the dashed circle in

[0020] . The reinforcing fiber lines 4 have a lower elongation rate and a higher tensile strength relative to the buffer pad 3. During the extrusion process of the buffer pad, due to the molecular cross-linking and curing of the buffer pad material, as well as the influence of mechanical force stretching, traction, etc., large deformations will occur. When the reinforcing fiber lines are connected to the buffer pad, they will hinder various deformations caused by the above factors during the extrusion curing process and storage conditions, making the size of the buffer pad stable. Thus, in the final assembly process of the product, based on the correct cutting length and high dimensional stability, the assembly difficulty can be reduced.

[0021] In addition, the characteristics of the reinforcing fiber lines can be selected according to different application occasions of the bearing and other performance requirements of the buffer pad. For example, the reinforcing fiber lines 4 can have a higher rigidity relative to the buffer pad 3. Additionally or alternatively, the reinforcing fiber lines 4 can have a higher bending fatigue resistance relative to the buffer pad 3. Additionally or alternatively, the reinforcing fiber lines 4 can have a lower tensile fracture elongation rate relative to the buffer pad 3.

[0022] Generally, the buffer pad 3 is manufactured by an extrusion process. According to a preferred embodiment of the present invention, the reinforcing fiber lines 4 can be embedded in the buffer pad 3 and co-extruded with the buffer pad 3 during the extrusion process.

[0023] Preferably, as Figure 2 shown, the buffer pad 3 has a channel 30 for accommodating the steel wire 2. The reinforcing fiber lines 4 are embedded in a portion of the surface 34 of the channel 30 that has a maximum thickness D from the outer side surface 35 of the buffer pad (as Figure 2 shown by the dashed circle in the upper right corner in

[0024] . More preferably, the ratio of the diameter of the reinforcing fiber lines 4 to the maximum thickness can be 0.3 - 0.5. It should be understood that according to different requirements and the structure of the buffer pad, the reinforcing fiber lines can also be embedded at different positions.

[0025] Specifically, the buffer pad 3 generally has a first wall 31 and a second wall 32 connected to each other. Therefore, the reinforcing fiber lines 4 can be embedded in the connected portion of the first wall 31 and the second wall 32, which generally also corresponds to the portion of the surface 34 of the channel 30 that has a maximum thickness D from the outer side surface 35 of the buffer pad. Additionally or alternatively, the reinforcing fiber lines 4 can be embedded in the edge portion 310 of the first wall 31 (as Figure 2 shown by the dashed circle in the lower right corner in Figure 2as shown by the dotted circle in the upper left corner). Embedding reinforcing fiber lines at multiple locations can better improve the performance of the buffer pad.

[0026] Preferably, the buffer pad 3 can be formed of nitrile rubber, butyl rubber, silicone rubber, polyurethane elastomer, styrene-butadiene rubber, or chloroprene rubber. Thus, the buffer pad can not only have sufficient elasticity to achieve good shock absorption, but also have good oil resistance and the like.

[0027] Among the above materials, nitrile rubber (NBR) and butyl rubber (IIR) have the best intrinsic damping performance, while silicone rubber, polyurethane elastomer (TPU), chloroprene rubber (CR), and styrene-butadiene rubber (SBR) have medium damping performance.

[0028] Due to the dense side methyl groups in butyl rubber NBR, its loss factor peak is large and wide, but its saturation is high and its processability is poor. After chlorination of butyl rubber, the molecular polarity is improved, and it has excellent processing performance. Nitrile rubber has a large secondary force in the molecular chain due to its strong polar cyano group, and its loss factor T = tanδ (damping value) is large, showing excellent damping performance, and also having excellent oil resistance, chemical corrosion resistance, solvent resistance, and excellent heat and low temperature resistance.

[0029] In the process of the shock-absorbing rubber being stressed, there is a certain phase difference between the deformation of the rubber and the stress of the rubber, and the stress of the rubber generally leads the rubber deformation by a certain phase angle.

[0030] The material used for the buffer pad should be near the glass transition region, with a serious hysteresis phenomenon, and can absorb a large amount of mechanical energy. The higher the loss peak of the material, the wider the glass transition temperature range, and the more consistent the temperature range value is with the external environment, the better the shock absorption effect. In addition, the influencing factors of shock absorption performance also include: molecular structure, vulcanization, fillers, and blending.

[0031] For wire race bearings, especially for bearings used in medical imaging equipment such as CT machines, the NBR molecular chain structure contains cyano groups, which has excellent oil resistance and cost performance. In contrast, the process cost of CR is relatively high.

[0032] Preferably, the reinforcing fiber line 4 can be formed of glass fiber, carbon fiber, aramid fiber, or steel fiber.

[0033] In a preferred embodiment, a glass core wire is formed by twisting 1,600 strands of standard glass fibers to serve as a reinforcing fiber wire. The standard glass core wire is 2,500 meters per kilogram (3,750 feet per pound, 400 tex) and has a diameter of 0.5 - 0.6 mm. The glass fiber filaments are a long fiber product, and through special bonding treatment of high-performance fibers represented by glass fibers, their bonding performance with NBR rubber is improved. The types of glass fibers include E glass (E-glass) and high-strength glass. Additionally, according to different needs, carbon fibers, aramid fibers, etc. can also be used. Glass fibers have an elastic modulus at the same level as aramid fibers, and at the same time possess excellent dimensional stability and flexural fatigue resistance. Carbon fibers have an elastic modulus at the same level as steel fiber wires, and have the advantages of excellent dimensional stability, flexural fatigue resistance, and light weight.

[0034] Preferably, the buffer pad 3 includes one or more segments of reinforcing fiber wires 4 embedded in the circumferential direction. That is to say, the reinforcing fiber wires 4 can be embedded in the buffer pad 3 around the entire circumference of the buffer pad 3, or can be embedded in the buffer pad 3 in segments along the circumferential direction.

[0035] Preferably, the outside of the reinforcing fiber wire 4 can also be coated with an adhesive to better bond with the buffer pad 3. The adhesive can be 233X.

[0036] Preferably, the reinforcing fiber wire 4 is composed of multiple strands of filaments twisted together, and the multiple strands of filaments are also bonded to each other and to the buffer pad 3 through an adhesive.

[0037] Preferably, the buffer pad 3 includes a peroxide and sulfur as curing agents, a filler system composed of carbon black and silica composite as fillers, a plasticizer, and / or a heavy metal salt as an anti-radiation agent.

[0038] The curing agent can be a combination of peroxide and sulfur. Peroxide vulcanization is a common vulcanization system. Since the C—C bond has a short bond length and a high bond energy, it has excellent high-temperature resistance and small compression set; however, the physical and mechanical properties of the rubber after peroxide vulcanization are poor, while the polysulfide bond (—Sx—) can endow the rubber with better strength and dynamic properties. Therefore, the method of using a combined vulcanization system is usually adopted to adjust the types and crosslinking structures of crosslinks in the rubber. Moreover, when NBR is used for the buffer pad, due to the presence of cyano groups in the NBR molecular chain structure, it has excellent oil resistance, and the oil resistance is related to the vulcanization system and the plasticizer content. Therefore, the combination of peroxide and sulfur minimizes the volume change of NBR in a high-temperature grease environment.

[0039] The type, content, particle size, and surface activity of the filler will all affect the mechanical properties, compression set, and damping performance of the buffer pad. According to the present invention, a filler system composed of silica (10 - 20%) and carbon black (30 - 40%) is adopted.

[0040] Oil media can extract soluble compounding agents (such as plasticizers, etc.) from the vulcanized rubber, resulting in the shrinkage or volume reduction of the vulcanized rubber. For bearing applications, a certain damping temperature threshold (i.e., the temperature range where tanδ > 0.3) also needs to be satisfied. Therefore, within a certain range, increasing the dosage of the plasticizer enhances the movement ability of rubber molecules, leading to an increase in mechanical losses generated under dynamic conditions, thereby improving the damping performance of the buffer pad to a certain extent.

[0041] For medical imaging applications such as CT machines, the main influence of ray radiation on the buffer pad is radiation crosslinking or radiation degradation. Heavy metal salts such as barium sulfate, due to their high density, can increase the density of the buffer pad when filled into it, reduce the penetration of rays, and improve the radiation resistance of the buffer pad.

[0042] On the other hand, the present invention also proposes a method for manufacturing the buffer pad as described above, including:

[0043] Step 1: Pretreat the reinforcing fiber wire 4;

[0044] Step 2: Introduce the reinforcing fiber wire 4 into the extrusion head for extruding the buffer pad 3, and reach the extrusion position corresponding to the embedding position of the reinforcing fiber wire in the buffer pad;

[0045] Step 3: Co - extrude the buffer pad 3 and the reinforcing fiber wire 4 through the extrusion head.

[0046] Preferably, the pretreatment in Step 1 can include, for example, heat treatment, surface pretreatment, coating with an adhesive, etc. Among them, the heat treatment can pre - heat the reinforcing fiber wire 4 to 200 - 250 °C to remove moisture and facilitate traction under low tension.

[0047] Preferably, in Step 2, a guiding device 5 and an inlet pipe 6 can be set up, see Figure 3 . The guiding device 5 is arranged upstream of the extrusion head 7 to introduce the reinforcing fiber wire 4 into the inlet pipe 6 at a gentle angle. The inlet pipe 6 is arranged in the extrusion head 7 to introduce the reinforcing fiber wire 4 to the extrusion position. Preferably, the fixed guiding device 5 can be a smooth ceramic component to avoid undesirable bending of the reinforcing fiber wire 4 passing through at too sharp an angle. In addition, the inlet pipe 6 can have a sufficient size to allow the reinforcing fiber wire 4 to pass through freely and minimize the friction between the reinforcing fiber wire 4 and the inlet pipe 6.

[0048] Preferably, in order to further optimize the performance of the already extruded cushion 3, the method further includes step 4: subjecting the cushion to high-temperature shaping, microwave vulcanization, and / or hot-air vulcanization.

[0049] See Figure 4 , which shows a schematic flow chart of a method for manufacturing a cushion according to a preferred embodiment of the present invention. At blocks 101 and 102, the reinforcing fiber threads are preheated and coated with an adhesive respectively; at block 103, the cushion and the reinforcing fiber threads are co-extruded from the extrusion head of an extruder; at block 104, the extruded cushion is subjected to a first high-temperature shaping; at block 105, the cushion is subjected to microwave vulcanization, with the temperature preferably being 240 - 260 °C; at block 106, the cushion is subjected to a first hot-air vulcanization, with the temperature preferably being 230 - 250 °C; at blocks 107 and 108, the cushion is cooled and drawn respectively; at block 109, the cushion is subjected to a second hot-air vulcanization, with the temperature preferably being 220 - 240 °C. Thus, the curing process of the cushion is basically completed, and then at blocks 110 and 111, the cushion is cooled and drawn respectively; at blocks 112, 113 and 114, the cushion is subjected to operations of inkjet coding, drawing, and winding and coiling for material collection in sequence.

[0050] The exemplary embodiments of the present disclosure have been described in detail above with reference to the preferred embodiments. However, those skilled in the art can understand that, without departing from the concept of the present disclosure, various modifications and variations can be made to the above specific embodiments, and various combinations can be made to the various technical features and structures proposed by the present disclosure, without exceeding the protection scope of the present disclosure. The protection scope of the present disclosure is determined by the appended claims.

Claims

1. A buffer pad (3) for a wire raceway bearing, the wire raceway bearing comprising a housing (1) and a steel wire (2), wherein the buffer pad (3) is arranged between the housing (1) and the steel wire (2) to partially surround the steel wire (2); in, The cushion pad (3) comprises a reinforcing fiber line (4) embedded in the cushion pad (3) along a circumferential direction and connected to the cushion pad (3); the reinforcing fiber line (4) has a lower elongation and a higher tensile strength than the cushion pad (3).

2. The cushioning pad (3) according to claim 1, wherein: The buffer pad (3) has a groove (30) for accommodating the steel wire (2), wherein the reinforcing fiber wire (4) is embedded in a portion of the surface (34) of the groove (30) having a maximum thickness away from the outer side surface (35) of the buffer pad; preferably, the ratio of the diameter of the reinforcing fiber wire (4) to the maximum thickness is 0.3-0.

5.

3. The cushioning pad (3) according to claim 1, wherein: The buffer pad (3) comprises a first wall (31) and a second wall (32) connected to each other, wherein: embedding the reinforcing fiber thread (4) in the connecting portion of the first wall (31) and the second wall (32); and / or embedding the reinforcing fiber thread (4) in the edge portion (310) of the first wall (31); and / or The reinforcing fiber thread (4) is embedded in the edge portion (320) of the second wall (32).

4. The cushioning pad (3) according to claim 1, wherein: The reinforcing fiber line (4) has higher rigidity than the buffer pad (3); The reinforcing fiber line (4) has higher bending fatigue resistance than the buffer pad (3); and / or The reinforcing fiber line (4) has a lower tensile elongation at break than the buffer pad (3).

5. The cushioning pad (3) according to claim 1, wherein: The buffer pad (3) is manufactured by an extrusion process, and during the extrusion process, the reinforcing fiber line (4) is embedded into the buffer pad (3) and co-extruded with the buffer pad (3).

6. The cushioning pad (3) according to claim 1, wherein: The buffer pad (3) is formed of nitrile rubber, butyl rubber, silicone rubber, polyurethane elastomer, styrene-butadiene rubber, or chloroprene rubber; and / or The reinforcing fiber line (4) is formed by glass fiber, carbon fiber, aramid fiber, or steel fiber.

7. The cushioning pad (3) according to claim 1, wherein: The cushion (3) comprises one or more reinforcing fiber lines (4) embedded in the circumferential direction; The reinforcing fiber line (4) is coated with adhesive on the outside so as to be bonded to the buffer pad (3); or The reinforcing fiber line (4) is composed of a plurality of filaments twisted together, and the plurality of filaments are also bonded together with each other and with the buffer pad (3) by an adhesive.

8. The cushioning pad (3) according to claim 1, wherein: The buffer pad (3) comprises peroxide and sulfur as curing agents, a filler system of carbon black and white carbon black as fillers, a plasticizer and / or a heavy metal salt as an anti-radiation agent.

9. A method for manufacturing a cushion (3) according to any one of claims 1 to 8, comprising: Step 1: pre-treating the reinforcing fiber line (4); Step 2: Introducing the reinforcing fiber wire (4) into an extrusion head for extruding the buffer pad (3) to an extrusion position corresponding to the embedding position of the reinforcing fiber wire (4) in the buffer pad (3); Step 3: Extruding the buffer pad (3) and the reinforcing fiber line (4) together through an extrusion head.

10. The method of claim 9, wherein: Preferably, the pretreatment in step 1 comprises: preheating the reinforcing fiber line (4) to 200-250° C., and / or applying an adhesive to the reinforcing fiber line (4); Preferably, in step 2, a guide device (5) and an introduction tube (6) are provided, wherein the guide device (5) is provided upstream of the extrusion head (7) to introduce the reinforcing fiber line (4) into the introduction tube (6) at a gentle angle, and the introduction tube (6) is provided in the extrusion head (7) to introduce the reinforcing fiber line (4) into the extrusion position; Preferably, the method further comprises step 4: performing high temperature shaping, microwave vulcanization, and / or hot air vulcanization on the buffer pad (3).

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