Patent Description:
With the popularization of automated warehouses, the use of high rack warehouse in the warehousing and logistics industry has greatly increased the space utilization. In addition, the warehouse logistics handling robot system adapted to the warehouse is attracting more and more attention. The stacker is one of the important tools in the warehouse logistics robot transport system. The retractable fork is one of the components of the stacker, while the roller bearing for supporting the retractable fork is the most important component, which is configured to sustain the retractable fork and improve motion smoothness of the retractable fork.

In the related technology, a load-bearing structure as shown in <FIG> is a roller bearing for supporting generally used in the retractable fork in the market. The load-bearing structure includes a bearing inner ring <NUM>, a bearing outer ring <NUM> for supporting, and a roller <NUM> disposed between the bearing inner ring <NUM> and the bearing outer ring <NUM>. The installation structure of the load-bearing structure shown in <FIG> includes a main frame body <NUM> fixedly installed in the stacker or devices with retractable fork, a bolt connector <NUM> successively extends through the roller bearing and the main frame body <NUM>, and a connection nut <NUM> threadedly connected to the bolt connector <NUM>. They are so arranged, that two or three roller bearings are arranged along the retraction direction of the retractable fork, and the distance between the outer surfaces of adjacent bearings is <NUM>-<NUM>. The bearing outer ring of the roller bearing services directly as a supporting wheel. The roller bearing may subject to impact load from the retractable fork when in use. Therefore, the wall thickness of the out ring of a roller bearing is increased by more than <NUM>% compared with a traditional solid needle bearing or cylindrical roller bearing, in order to improve the anti-impact capacity of the roller bearing, which results in a lower rated dynamic load, a lower load capacity and a shorter service life of the roller in the roller bearing. Patent document <CIT> shows a recirculating roller bearing according to the preamble of claim <NUM>.

The requirements on load capacity and transport speed of the retractable fork are becoming more stringent, while the volume of the retractable fork tends to be lightweight. Therefore, the structure and the occupied volume of the retractable fork haven't been greatly changed, i.e., the installation space of the roller bearing cannot be increased any more under the requirement of lightweight, that is, the service life of the roller bearing cannot be extended by increasing the volume of the roller of the roller bearing. The service life of the roller bearing is required to be longer under the industrial requirements of reducing costs and increasing profitability. The traditional roller bearings cannot meet the developing requirements of the retractable fork, which is urgent to be improved.

A recirculating roller bearing is provided, in order to increase load capacity and service life of the bearing in a limited installation space.

The recirculating roller bearing provided adopts the following technical solution.

A recirculating roller bearing, comprising a front cover plate, a rear cover plate, an inner supporter, a sealing covering, a plurality of rolling carriers and at least one connector, wherein:.

With the above technical solution, the front cover plate is firstly mounted on the inner supporter. The front cover plate is then laid flat on a plane. A circulating guiding path that opened upwards on a single side is formed between the front cover plate and the inner supporter. At this time, the plurality of rolling carriers are arranged in the circulating guiding path that opened upwards on a single side. Then the rear cover plate is mounted on a side of the inner supporter away from the front cover plate, so as to limit the rolling carriers from two opposite sides. Afterwards the sealing covering is arranged around the inner supporter and mounted between the front cover plate and the rear cover plate in a sealing manner, thereby forming the circulating guiding path. The rolling carriers are filled in the circulating guiding path. Finally, the inner supporter, the front cover plate and the rear cover plate are mounted on the main frame body by the connector. When in use, the rolling carriers passing the opened load-bearing portion are in an exposed state by using the opened load-bearing portion of the circulating guiding path, so as to form a rolling fit with the retractable fork.

Compared with the traditional needle roller bearings with sealing element, the outer ring structure servicing as a rolling wheel is removed. The rolling carrier is directly used to bear load. Therefore, the diameter Dw of the rolling carrier in the present application is certainly larger than the needle diameter Dw of the traditional needle roller bearing with sealing element and may be more than twice larger. According to the rated dynamic load formula of a radial roller bearing: Cr=bmfc(iLwecosα)<NUM>/<NUM>Z<NUM>/<NUM>Dw<NUM>/<NUM>, the rated dynamic load of the present application is larger than the rated dynamic load of the traditional needle roller bearing with sealing element and may be more than one time larger. According to the basic rated service life formula of a radial roller bearing: <MAT>, the rated fatigue life of the present application is longer than that of the traditional needle roller bearing with sealing element with same dimension and may be more than <NUM> times longer, greatly extending maintenance cycle and reducing maintenance cost. The load capacity and service life are increased not by singly increasing the dimension of the original structure. The whole dimension isn't increased compared with the roller bearing with outer ring, thereby being applicable to the current development of lightweight.

In addition, a plurality of rolling carriers are adopted in the present application to equally bear external load. Therefore, the contact strain of the portion of the retractable fork and stacker corresponding to the main frame body is less than <NUM>% of the original contact strain. Therefore, the service life of the portion of the retractable fork and stacker corresponding to the main frame body is extended more than <NUM> times. Further, the equipment such as the retractable fork and stacker in the present application has a smaller dimension under the same load-bearing condition, so that the equipment such as the retractable fork and stacker is smaller and compacter, satisfying the development of lightweight.

In addition, the portion of the sealing covering at two ends of the opened load-bearing portion is higher than the load-bearing point of the rolling carrier. The abutment and sealing between the sealing covering and the retractable fork is realized by using the elasticity of the sealing covering itself. In one aspect, external dust and moisture are avoided to enter the circulating guiding path. In another aspect, the portion plays a role of scraper, preventing the lubricating grease from moving with the retractable fork and in turn from being brought out of the circulating guiding path, thereby ensuring the lubrication efficiency of the rolling carrier.

Preferably, the connector successively extends through the front cover plate, the inner supporter and the rear cover plate, an extension end of the connector is provided with a connection portion, the connection portion is configured to be detachably connected to the main frame body, and an end of the connector away from the extension end is in limiting and abutment fit with the inner supporter.

With the above technical solution, the connecter successively extends through the front cover plate, the inner supporter and the rear cover plate, and the limiting and abutment fit is formed between the connector and the front cover plate, so that the whole structure is easy to mount on the main frame body and this mounting manner can further increase the installation tightness between the front cover plate and the inner supporter.

Preferably, the front cover plate is provided with a first through hole, the inner supporter and the rear cover plate are provided with a second through hole respectively, a diameter of the first through hole is larger than a diameter of the second through hole. The end of the connector away from the extension end is provided with a limiting protrusion, the limiting protrusion is configured to be embedded in the first through hole, and the limiting protrusion abuts against a side of the inner supporter close to the front cover plate.

With the above technical solution, the first through hole of the front cover plate and the second through hole of the inner supporter form a countersunk hole, so as to hide the limiting protrusion of the connector by the first through hole, thereby saving installation space. In addition, a limiting and abutment fit with the inner supporter is realized by the limiting protrusion, so as to realize installation tightness between the inner supporter and the front cover plate.

Preferably, the connection portion is configured as a fixing thread, which is configured to be engaged with a fastening nut, and two ends of the connector along an extension direction thereof are provided with a polygon countersunk groove respectively.

With the above technical solution, the connection portion is configured as the fixing thread, so as to realize assembly between the connector and the main frame body by combining with the fastening nut in actual installation. In addition, the connector can be detached in actual detachment by using the polygon countersunk groove inside the connector in combination with an inner spanner, thereby realizing a detachable assembly between the connector and the main frame body.

Preferably, the connector is provided with an oil through groove communicating with the polygon countersunk groove, and the inner supporter is provided with a communicating groove communicating with the circulating guiding path and the oil through groove.

With the above technical solution, lubricating grease is introduced in the oil through groove in actual use in order to improve smoothness of the rolling carriers circulating in the circulating guiding path. The lubricating grease will further enter the circulating guiding path through the oil through groove and the communicating groove, to lubricate the rolling carriers.

Preferably, the plurality of rolling carriers are configured as cylinder rollers, two ends of each of the cylinder rollers are provided with a guiding protrusion respectively, opposite sides of the front cover plate and the rear cover plate facing to each other are provide with a circulating guiding groove in a same circulating direction as the circulating guiding path respectively, a circumferential surface of each of the cylinder rollers is in rolling fit with the inner supporter, and the guiding protrusion is configured to be embedded in the circulating guiding groove.

With the above technical solution, the load-bearing area is greatly increased by using the cylinder rollers. The motion stability of the cylinder rollers in the circulating guiding path is greatly improved by the embedded fit between the guiding protrusion and the circulating guiding groove.

Preferably, there are at least two connectors, and the at least two connectors are arranged at intervals along the retraction direction of the retractable fork.

With the above technical solution, there are at least two connectors, so as to increase installation stability of the front cover plate, the inner supporter, and the rear cover plate on the main frame body.

Preferably, there is one connector, which is shaped as a cylinder.

With the above technical solution, there is one connector, while the connector is shaped as a cylinder, so that the front cover plate, the inner supporter and the rear cover plate that are fixedly connected to each other as a whole can rotate relative to the connector, thereby facilitating adjusting the angle between the opened load-bearing portion and the contact surface of the retractable fork, ensuring the fit between the opened load-bearing portion and the retractable fork.

Preferably, a segment of the circulating guiding path at the opened load-bearing portion extends linearly, and the opened load-bearing portion extending linearly is parallel to the retraction direction of the retractable fork.

With the above technical solution, the segment of the circulating guiding path at the opened load-bearing portion extends linearly and the opened load-bearing portion extending linearly is parallel to the retraction direction of the retractable fork, greatly increasing the load-bearing area of the retractable fork by the load-bearing structure, and in turn increasing anti-load capacity and service life of the whole structure.

In summary, at least one of the following beneficial effects are realized:.

The present application is further described in detail below in combination with <FIG>.

The embodiments of the present application disclose a recirculating roller bearing.

Referring to <FIG> and <FIG>, the recirculating roller bearing includes a bearing body <NUM> and a connector <NUM>, in which the connector <NUM> is detachably connected to the bearing body <NUM>, and the connector <NUM> is detachably fixedly connected with a main frame body of a stacker or other machines and devices equipped with a retractable fork structure. The main frame body is fixedly arranged in a frame structure of a stacker or other machines and devices. The bearing body <NUM> is detachably fixed on the main frame body of a stacker or other machines and devices equipped with a retractable fork structure by the connector <NUM>.

Referring to <FIG> and <FIG>, the bearing body <NUM> includes a front cover plate <NUM>, a rear cover plate <NUM>, an inner supporter <NUM> and a sealing covering <NUM>. The front cover plate <NUM> and the rear cover plate <NUM> are detachably connected to two opposite sides, namely two sides in a thickness direction, of the inner supporter <NUM> by fastening bolts respectively. The section areas of the front cover plate <NUM> and the rear cover plate <NUM> are identical and both larger than the lateral area of the inner supporter <NUM> in the thickness direction. An accommodation space <NUM> for accommodating rolling carriers <NUM> is formed between two side faces of the front cover plate <NUM> and the rear cover plate <NUM> facing to each other and the periphery of the inner supporter <NUM>.

Referring to <FIG> and <FIG>, the sealing covering <NUM> is made of metal or rubber. The sealing covering <NUM> is arranged around the inner supporter <NUM> along the peripheries of the front cover plate <NUM> and the rear cover plate <NUM>. Two lateral edges of the sealing covering <NUM> are arranged between the peripheries of the front cover plate <NUM> and the rear cover plate <NUM> in a sealing manner by sealant. That is, the sealing covering <NUM> is arranged around the accommodation space <NUM>, such that a circulating guiding path <NUM> is formed between the accommodation space <NUM> defined by the front cover plate <NUM>, the rear cover plate and the inner supporter <NUM> and the sealing covering <NUM>. The circulating guiding path <NUM> includes a sealing portion <NUM> and an opened load-bearing portion <NUM>.

Referring to <FIG> and <FIG>, the bearing body <NUM> further includes a plurality of rolling carriers <NUM>, which are filled in the circulating guiding path <NUM>. In the embodiment of the present application, each rolling carrier <NUM> is configured as a cylinder roller. Two ends of each rolling carrier <NUM> in the axial direction are both integrally formed with a guiding protrusion <NUM>. Correspondingly, sides of the front cover plate <NUM> and the rear cover plate <NUM> facing to each other are provided with a circulating guiding groove <NUM> in a same circulating direction as the circulating guiding path <NUM> respectively. A rolling fit is formed between the circumferential surface of any cylinder roller and the sidewall of the inner supporter <NUM> perpendicular to the thickness direction thereof. The guiding protrusions <NUM> on two ends of each cylinder roller in the axial direction are respectively embedded in the circulating guiding grooves <NUM> of the front cover plate <NUM> and the rear cover plate <NUM>, so as to ensure motion stability of the cylinder roller in the circulating guiding path <NUM>.

Referring to <FIG> and <FIG>, the front cover plate <NUM>, the inner supporter <NUM>, the rear cover plate <NUM> and the circulating guiding path <NUM> are all shaped in a trapezoid shape in the embodiment of the present application. The opened load-bearing portion <NUM> corresponding to the lower bottom of the trapezoid is parallel to the retractation direction of the retractable fork, that is, the opened load-bearing portion <NUM> is extends linearly, greatly increasing the load-bearing area. When the rolling carriers <NUM> are positioned at the opened load-bearing portion <NUM> of the circulating guiding path <NUM>, a rolling fit is formed between the rolling carriers and the retractable fork, playing a role of supporting the retractable fork simultaneously.

That is to say, the rolling carrier <NUM> directly services as bearing component, which is configured to abut against the retractable fork. Compared with the needle roller bearings generally used in the existing technology, the outer ring structure servicing as a rolling wheel is removed. Therefore, the diameter Dw of the rolling carrier <NUM> in the embodiment of the present application is larger than the needle diameter Dw of the traditional needle roller bearing and may be more than twice larger. According to the rated dynamic load formula of a radial roller bearing: Cr=bmfc(iLwecosα)<NUM>/<NUM>Z<NUM>/<NUM>Dw<NUM>/<NUM>, the rated dynamic load of the present application is increased to be more than one time larger than the rated dynamic load of the traditional sealing needle roller bearing. According to the basic rated service life formula of a radial roller bearing: <MAT>, the rated fatigue life of the present application is increased to be more than <NUM> times longer than that of the traditional sealing needle roller bearing with same dimension, greatly extending the maintenance cycle and reducing the maintenance cost.

In addition, a plurality of rolling carriers <NUM> are adopted in the present application to equally bear external load. The contact strain of the retractable fork and the main frame body is less than <NUM>% of the original contact strain. Therefore, the service life of the retractable fork and the main frame body is extended more than <NUM> times. Further, the retractable fork and stacker in the present application has a smaller dimension under the same load, so that the retractable fork and stacker is smaller and compacter, satisfying the development of lightweight.

Referring to <FIG> and <FIG>, the connector <NUM> is configured to be a connection bolt, which is shaped as a cylinder. The connection bolt includes a limiting protrusion <NUM>, a smooth rod portion <NUM> and a connection portion <NUM>, the connection portion is configured to be detachably connected to the main frame body. The front cover plate <NUM> is provided with two first through holes <NUM>, which are spaced with each other along the retraction direction of the retractable fork. Similarly, the inner supporter <NUM> and the rear cover plate <NUM> are provided with two second through holes <NUM> respectively, which are spaced with each other along the retraction direction of the retractable fork. The two first through holes <NUM> are respectively corresponding to the two second through holes <NUM>. The first through hole <NUM> is coaxial with the corresponding second through hole <NUM>. The axis of any first through hole <NUM> and second through hole <NUM> is perpendicular to the retraction direction of the retractable fork. There are two connection bolts. Since the structures and the connection manners to the bearing body <NUM> of the connection bolts are the same, the connection manner between one of the connection bolts and the bearing body <NUM> is exemplarily explained.

Referring to <FIG> and <FIG>, the connection bolt successively extends through the first through hole <NUM> of the front cover plate <NUM>, the second through holes <NUM> of the inner supporter <NUM> and the rear cover plate <NUM> with its connection portion <NUM>. The limiting protrusion <NUM> of the connection bolt is embedded in the first through hole <NUM> of the front cover plate <NUM>, that is, the first through hole <NUM> and the second through hole <NUM> from a countersunk hole here, so that the limiting protrusion <NUM> of the connection bolt can not only limit the front cover plate <NUM>, but also abut against the inner supporter <NUM>, which is beneficial to fixation of the front cover plate <NUM> with the inner supporter <NUM>. The inner supporter <NUM> and the rear cover plate <NUM> are both positioned at the smooth rod portion <NUM> of the connection bolt.

Referring to <FIG>, the connection portion <NUM> of the connection bolt is configured as a fixing thread. Both ends of the connection bolt in the axial direction are provided with a polygon countersunk groove <NUM> respectively. In the embodiment of the present application, the polygon countersunk groove <NUM> is a hexagon countersunk groove. The thread connection between the fastening bolt and the fastening nut can be realized on two ends of the connection bolt in axial direction by an inner hexagon spanner.

Referring to <FIG> and <FIG>, an oil through groove <NUM> communicating with the polygon countersunk groove <NUM> is provided in the connection bolt. The oil through groove <NUM> includes a first oil groove <NUM> parallel to the connection bolt in axial direction and a second oil groove <NUM> perpendicular to the first oil groove <NUM>. A communicating groove <NUM> is provided in the inner supporter <NUM> corresponding to another open end of the second oil groove <NUM>. The communicating groove <NUM> is communicated with the circulating guiding path <NUM>, and the communicating portion of the communicating groove <NUM> extends vertically upwards.

In practice, the operator introduces lubricating grease into the oil through groove <NUM> by an oiling device. The grease will enter the second oil groove <NUM> from the first oil groove <NUM>, and further enter the circulating guiding path <NUM> to lubricate the rolling carriers <NUM>.

In other embodiments, the distance between two connection bolts can be adjusted according to the service conditions, so as to meet different use requirements.

Referring to <FIG>, a load-bearing point <NUM> is defined at a contact position between the radially outmost portion of the rolling carrier <NUM> at the opened load-bearing portion <NUM> and the retractable fork. Each of the two ends of the sealing covering <NUM> at the opened load-bearing portion <NUM> is provided with a protruded portion <NUM> protruding relative to the load-bearing point <NUM>, in order to prevent the lubricating grease from leaking out of the opened load-bearing portion <NUM>. The protruded portion <NUM> is configured to be elastic and abuts against a contact surface of the retractable fork in a sealing manner. The protruding height of the sealing covering <NUM> is set as <NUM>, to avoid resistance caused by friction and to achieve a better sealing contact effect.

The implementation principle of the embodiment in the present application is: the front cover plate <NUM> is fixedly connected with the inner supporter <NUM> by fastening screw in actual installation process. The front cover plate <NUM> is laid flat on a plane, so that the inner supporter <NUM> faces upwards. The corresponding number of rolling carriers <NUM> are placed in the accommodation space <NUM> between the front cover plate <NUM> and the inner supporter <NUM> one by one, meanwhile, the guiding protrusion <NUM> of each rolling carrier <NUM> is embedded in the circulating guiding groove <NUM> of the front cover plate <NUM>.

Afterwards, the rear cover plate <NUM> is fixed on the side of the inner supporter <NUM> away from the front cover plate <NUM> by a fastening screw. The guiding protrusion <NUM> on the other end of the rolling carrier <NUM> is ensured to be embedded in the circulating guiding groove <NUM> of the rear cover plate <NUM> in the fixing process.

Then the sealing covering <NUM> are connected between the front cover plate <NUM> and the rear cover plate <NUM> in a sealing manner by a sealant along the peripheries of the front cover plate <NUM> and the rear cover plate <NUM>, so as to form the opened load-bearing portion <NUM> and the sealing portion <NUM>. The opened load-bearing portion <NUM> is ensured to be positioned on the lower bottom of the trapezoid of the front cover plate <NUM> and the rear cover plate <NUM> in the process of the connection in a sealing manner.

Finally, two connection bolts successively extend through the first through hole <NUM> and the second through holes <NUM> of the bearing body <NUM>, and the fixing threads of the two connection bolts extend through the main frame body and are engaged with the fastening nut, so as to fasten the bearing body <NUM> on the main frame body.

Referring to <FIG>, this embodiment differs from Embodiment two in that: there is one connector <NUM>, that is, there is one connection bolt. In the embodiment of the present application, the bearing body <NUM> consisting of the front cover plate <NUM>, the inner supporter <NUM>, the rear cover plate <NUM> and the sealing covering <NUM> has an isosceles triangle shape. The opened load-bearing portion <NUM> of the bearing body <NUM> is positioned at the base of the bearing body <NUM>.

The bearing body <NUM> may rotate relative to the connection bolt in the actual installation process. The operator can adjust the fit of the opened load-bearing portion <NUM> of the bearing body <NUM> relative to the contact surface of the retractable fork. Since the bearing body <NUM> has an isosceles triangle shape, the bearing body <NUM> is hard to collide with other structures during adjustment. Therefore, the operator can correspondingly install a plurality of recirculating roller bearings in the embodiment of the present application on the main frame body according to the service condition requirements, realizing collation of multiple combinations.

The lubricating grease is required to be added regularly in the technical solutions of the above embodiments. The normal operation of the recirculating roller bearing tends to be easily influenced when the operator doesn't add the lubricating grease for a long time. Therefore, referring to <FIG>, a lubricating groove <NUM> is provided in an outer sidewall of the inner supporter <NUM> in the embodiment. A self-lubricating body <NUM> is placed in the lubricating groove <NUM>. When the rolling carriers <NUM> pass by the lubricating groove <NUM>, the self-lubricating body <NUM> in the lubricating groove <NUM> is scraped. The self-lubricating body <NUM> lubricates the bearing body <NUM> with the motion of the rolling carriers <NUM>.

The lubricating groove <NUM> is arranged at the area corresponding to the sealing portion <NUM>. Preferably, the lubricating groove <NUM> is located in the middle of the inclined surface of the inner supporter <NUM>. For example, the lubricating groove <NUM> is arranged on two waists of the trapezoid when the inner supporter <NUM> has a trapezoid shape; the lubricating groove <NUM> is arranged on two sides corresponding to the non-load side when the inner supporter <NUM> has an isosceles triangle shape.

A mounting base134 is disposed in the lubricating groove <NUM>. The mounting base <NUM> is a plastic structure, which is interference fitted in the lubricating groove <NUM>. The self-lubricating body <NUM> is mounted in the mounting base <NUM>. The self-lubricating body <NUM> is a resin with lubricating oil, in which the lubricating oil is retained in gaps between resin particles. In this embodiment, the self-lubricating body <NUM> protrudes out of the lubricating groove <NUM> partly. The lower middle part of the self-lubricating body <NUM> is excavated, so that the self-lubricating body <NUM> has an elastic deformation in the mounting base <NUM> when sustaining pressure from the roller, ensuring the upper side of the self-lubricating body <NUM> to protrude out of the lubricating groove <NUM> and abut against the surface of the rolling carriers <NUM> all along. Meanwhile, two ends of the upper side of the self-lubricating body <NUM> are configured to be conical surfaces, so as to facilitate the rolling carriers <NUM> to scrape grease from the self-lubricating body <NUM>.

Since each rolling carrier <NUM> scrapes a small amount of grease at one time, using the structure in this embodiment can ensure that the equipment is not required to be added with grease for life, that is, the bearing can be maintenance-free for life by using this structure.

The sealing covering <NUM> is configured to be an annular structure, in order to further improve sealing effect and reduce wastage of the lubricating grease. A load-bearing groove <NUM> is provided in an area of the sealing covering <NUM> corresponding to the opened load-bearing portion <NUM>, and the load-bearing groove <NUM> extends through the sealing covering <NUM> only in a load-bearing direction. The sealing covering <NUM> can abut against the portions of the front cover plate <NUM> and the rear cover plate <NUM> corresponding to the opened load-bearing portion <NUM> in a sealing manner. Referring to <FIG>, the load-bearing groove <NUM> vertically extends through the sealing covering <NUM>, so that a portion of the sealing covering <NUM> abuts against the ends of the rolling carrier <NUM> at the load-bearing position, reducing leakage of the lubricating grease. In addition, the sealing covering <NUM> is easy to produce, thereby no bend and crimp etc. are necessary.

Referring to <FIG>, this embodiment differs from Embodiment one in that: there is one connector <NUM>. Certainly, the number of the connector <NUM> can be two or more in other embodiments. In this embodiment of the present application, the bearing body <NUM> consisting of the front cover plate <NUM>, the inner supporter <NUM>, the rear cover plate <NUM> and the sealing covering <NUM> has a substantially ellipse shape, so that the circulating guiding path <NUM> includes an arc-shaped sealing portion <NUM> and two linear opened load-bearing portion <NUM>. In this embodiment, there are two load-bearing grooves <NUM>. The load-bearing groove <NUM> vertically extends through the sealing covering <NUM>, so that a portion of the sealing covering <NUM> abuts against the ends of the rolling carrier <NUM> at the load-bearing position.

The embodiment of the present application further discloses a supporting structure for retractable fork.

Referring to <FIG>, the supporting structure for retractable fork includes the main frame body <NUM> in the above embodiments and two recirculating roller bearings disclosed in Embodiment <NUM>. The two recirculating roller bearings are arranged on the main frame body <NUM> at interval in a direction parallel to the retraction direction of the retractable fork.

Referring to <FIG>, in the actual installation process, after the bearing body <NUM> is assembled, the connection bolt is introduced through the bearing body <NUM> and then the main frame body <NUM>. The bearing body <NUM> is fixed on the main frame body <NUM> by engagement of the threaded portion of the connection bolt with a fastening nut. However, before screwing the fastening nut, the operator can drive the bearing body <NUM> to rotate, so as to adjust the fit between the opened load-bearing portion <NUM> of the bearing body <NUM> and the contact surface of the retractable fork. Or one bearing body <NUM> can be prefixed firstly. When the other bearing body <NUM> is being fixed by another connection bolt, the fit between two bearing bodies <NUM> relative to the contact surface of the retractable fork can be adjusted by rotation while the bearing bodies <NUM> support the retractable fork, since two points determine a line.

Referring to <FIG>, the roller bearing in the related technology is mounted on the main frame body <NUM> to form a supporting structure. The roller bearing in the related technology is arranged with a single axis, but the installation number of the roller bearings is required to be increased to realize a higher bearing capacity of the supporting structure. In actual use, compared with the embodiment of the present application, this supporting structure requires at least three roller bearings under the same load. Once the installation number of the roller bearings is larger than two, the operator must spend more time on adjustment of the position of the third roller bearing relative to the other two roller bearings during installation, such that each roller bearing can bear load, which increases the installation and adjustment time of the whole structure.

No additional components for adjusting the straightness between two bearing bodies <NUM> are not required when using the technical solution of the present application, thereby reducing cost and facilitating the whole installation and adjustment, so as to realize a uniform force of the bearing and to increase the service life.

Claim 1:
A recirculating roller bearing, comprising a front cover plate (<NUM>), a rear cover plate (<NUM>), an inner supporter (<NUM>), a sealing covering (<NUM>), a plurality of rolling carriers (<NUM>) and at least one connector, wherein:
the front cover plate (<NUM>) and the rear cover plate (<NUM>) are detachable connected to two opposite sides of the inner supporter (<NUM>) respectively, the sealing covering (<NUM>) is arranged between the front cover plate (<NUM>) and the rear cover plate (<NUM>) in a sealing manner and is arranged around the inner supporter (<NUM>);
a circulating guiding path (<NUM>) is formed between the front cover plate (<NUM>), the rear cover plate (<NUM>), the inner supporter (<NUM>) and the sealing covering (<NUM>), the circulating guiding path (<NUM>) comprises a sealing portion (<NUM>) and an opened load-bearing portion (<NUM>);
the plurality of rolling carriers (<NUM>) are all filled in the circulating guiding path (<NUM>), each of the plurality of rolling carriers (<NUM>) is in rolling fit with the inner supporter (<NUM>), and each of the plurality of rolling carriers (<NUM>) is in rolling fit with a retractable fork when passing the opened load-bearing portion (<NUM>) of the circulating guiding path (<NUM>);
characterized in that:
the connector is configured to detachably fix the inner supporter (<NUM>), the front cover plate (<NUM>) and the rear cover plate (<NUM>) on a main frame body (<NUM>);
a load-bearing point (<NUM>) is defined at a contact position between a radially outmost portion of the plurality of rolling carriers (<NUM>) at the opened load-bearing portion (<NUM>) and the retractable fork, two ends of the sealing covering (<NUM>) at the opened load-bearing portion (<NUM>) are provided with a protruded portion (<NUM>) protruding relative to the load-bearing point (<NUM>) respectively, characterised in that
the protruded portion (<NUM>) is elastic and is configured to abut against a contact surface of the retractable fork in a sealing manner.