storage of a conveyor system and a conveyor system

Abstract

The invention relates to a bearing (10) of a conveyor system comprising at least one outer ring (12), at least one inner ring (14), rolling elements (16) designed to roll on the outer ring and the inner ring, and lubricating grease for lubricating the movements of the rolling elements relative to the outer ring and the inner ring. It is proposed that the lubricating grease contains molybdenum disulfide.

Description

The invention relates to a storage facility of a conveying installation and to a conveying installation.It is known to use spherical roller bearings for movably mounting a belt of a conveyor system. Examples of such bearings are bearings 22205 E and 22206 E (cf. SKF Auslegeschrift 2018, page 792). The bearings do not comprise seals. In the arrangement in the conveyor system, the bearings are sealed with external seals.The object of the invention is in particular to provide a bearing of a conveying installation which has a high degree of efficiency. The object is achieved according to the invention by the features of claim 1 and by the features of claim 10, wherein advantageous embodiments and further embodiments of the invention can be taken from the dependent claims.The invention is based on a bearing of a conveying installation having at least one outer ring, at least one inner ring, rolling bodies which are designed to roll on the outer ring and the inner ring, and grease for lubricating movements of the rolling bodies relative to the outer ring and the inner ring.It is proposed that the grease contains molybdenum disulfide. As a result, a bearing of a conveying installation can be provided which has a high degree of efficiency. In particular, a long life of the grease can be achieved. In particular, during the start-stop operations of the conveyor, a lubricant film with molybdenum disulfide is ensured, which prevents metal-metal contact and reduces the formation of harmful wear particles. In particular, with the aid of molybdenum disulfide, lubrication can be achieved which is unaffected by dilute acids and oxygen.Advantageously, the sum of the masses of molybdenum and molybdenum ions in the molybdenum disulfide contained in the grease deviates from 6900 μg per gram of the grease by at most 2900 μg per gram of the grease, preferably by at most 1200 μg per gram of the grease and most preferably by at most 400 μg per gram of the grease. This allows efficient lubrication and a long service life of the grease and the bearing to be achieved, in particular despite frequent start-stop operations of the conveyor system.It is also proposed that a row of rolling elements of the bearing contains less than 1.05 rolling elements per centimeter of pitch circle circumference of the row and preferably less than 0.879 rolling elements per centimeter of pitch circle circumference of the row. As a result, energy can be saved during operation of the conveying installation without impairing the service life of the bearing in the conveying installation. In addition, costs can be saved.The bearing is advantageously a spherical roller bearing which does not require a guide ring. This makes it possible to avoid unnecessary friction, so that energy can be saved during operation.It is furthermore proposed that at least one cage of the bearing is hardened. As a result, a long service life of the bearing can be achieved in that a premature failure of the cage, in particular due to impact forces of the rolling bodies during frequent start-stop processes of the conveying system, is avoided. The cage can be nitrile-hardened in particular. In particular, two cages of the bearing can be hardened, in particular nitrile-hardened.In particular, the bearing can be a spherical roller bearing.It is further proposed that the bearing comprises a cage which comprises a first surface on an axially outer end side, which is located at a radially inner end of the end side and which has a smaller axial distance from a center of mass of the cage than a second surface of the end side. In this way, contact between the cage and a seal of the bearing during operation can be avoided, as a result of which energy can be saved. In particular, the first surface can be configured annularly.Advantageously, a maximum radial load of the bearing during operation is 6580 Newtons and / or a maximum axial load of the bearing during operation is 566 Newtons. A low mass of the bearing can thereby be achieved.Advantageously, the grease contains graphite. This can achieve improved lubrication in the event of a breakdown of the oil film.In particular, a first seal is attached to the outer ring or the inner ring to seal a space between the inner ring and the outer ring. Specifically, a second seal is fixed to the outer ring or the inner ring to seal a space between the inner ring and the outer ring.It is furthermore proposed that a base oil of the grease is mineral oil and / or a thickener of the grease is lithium and / or calcium. As a result, a high oxidation stability and a long life of the grease can be achieved.It is further proposed that a row of the rolling elements of the bearing contains between 67% and 87%, preferably between 72% and 82%, of the number of such rolling elements that the row can contain at most. Thereby, the bearing can bear a sufficient load with light weight and low power consumption during operation. In particular, all rolling elements in the embodiment are identical. In particular, a further row of the rolling bodies of the bearing contains between 67% and 87%, preferably between 72% and 82%, of the number of such rolling bodies that the further row can contain at most.Furthermore, a conveying installation with a bearing as described in the preceding text is proposed, wherein the bearing rotatably supports a roller of the conveying installation, wherein the roller movably supports a belt of the conveying installation. As a result, a conveying installation and a bearing of a conveying installation can be achieved which have a high degree of efficiency. In particular, the roller can transmit a drive to the belt.Further advantages result from the following description of the drawings. Examples of embodiments of the invention are shown in the drawings. The drawings, specification and claims contain numerous features in combination. The skilled person will expediently also consider the features individually and form them into meaningful further combinations. FIG. 1 shows a half section through a bearing of a conveying system according to the invention, FIG. 2 shows a half-section through an alternative embodiment of a cage of a bearing according to the invention, FIG. 3 shows a half section through an alternative embodiment of a bearing of a conveying system according to the invention, and Fig. 4 shows a part of a conveyor with a store according to the invention.FIG. 1 shows a half section through a bearing 10 of a conveying system according to the invention. The bearing is a spherical roller bearing. It comprises an outer ring 12, an inner ring 14 and rolling bodies 16 which are designed to roll on the outer ring and the inner ring. The bearing comprises lubricant (not shown) for lubricating the movements of the rolling bodies with respect to the outer ring and the inner ring. A space 36 between the inner ring and the outer ring is sealed by a first seal 38 and a second seal 40. The first seal is positively secured to the outer ring and is located at a first axial end of the bearing. The second seal is likewise positively fastened to the outer ring and is located at a second axial end of the bearing. The first seal is comprised of a metal part and a nitrile butadiene rubber part. The second seal is identical in its embodiment to the first seal. The free part of the space 36 is filled with fat to the extent of 35% to 45%. The bearing includes a first row 18 of rollers and a second row 19 of rollers.The grease contains molybdenum disulfide. The sum of the masses of molybdenum and molybdenum ions in the molybdenum disulfide contained in the grease deviates from 6900 μg per gram of grease by at most 2900 μg per gram of grease. Preferably, the sum of the masses of molybdenum and molybdenum ions in the molybdenum disulfide contained in the grease deviates from 6900 μg per gram of the grease by at most 400 μg per gram of the grease. The grease also contains graphite.In addition, the fat contains 2450 mg / kg lithium, 1200 mg / kg phosphorus, 5400 mg / kg zinc, 2900 mg / kg calcium, less than 2 mg / kg barium and 20 mg / kg magnesium. These values can vary by up to 30%, preferably by up to 15%.The operating temperature range of the grease is -20 to 120°C. The base oil viscosity of the grease is 500 mm 2 / sec at 40°C and 32 mm 2 / sec at 100°C.The content and properties of the fat have proved to be very advantageous in extensive investigations.Both rows 18, 19 of rolling elements 16 of the bearing contain less than 1.05 rolling elements per centimeter of pitch circle circumference of the row. The bearing also lacks a guide ring.A cage 20 and a cage 21 keep the rolling elements at a distance from one another. The cage bars are located in the region of the pitch circle. Both cages are nitrile hardened. The cages are pressed steel sheet cages.The maximum radial load of the bearing during operation is 6580 Newtons and the maximum axial load of the bearing during operation is 566 Newtons.The base oil of the grease is mineral oil and the thickener of the grease is lithium and calcium. The base oil comprises about 79 percent by weight of the grease. The NLGI consistency class of the grease is 2 or 3. The grease is a highly viscous grease with high oxidation stability. Molybdenum disulfide is used as a dry lubricant because of its low friction and robustness.FIG. 4 shows a section through a part of a conveyor system with the bearing 10. The further bearing 11 is identical in its embodiment to the bearing 10. The roller carries a belt 34 of the conveyor system in a movable manner. With the aid of the belt, the conveying system can transport packages, for example, which are sent by mail. An upper portion of the belt performs a translatory motion to transport objects (e.g., packages). The pulley may transmit a drive to the belt to cause the belt to move.A limit rotational speed of the inner ring is 1800 revolutions per minute. The limit rotational speed of the outer ring is 1400 revolutions per minute. The pitch circle diameters of the two rows are the same. They are 39.5 millimeters. The size of the rolling elements is 7.13 millimeters by 6.6 millimeters, wherein the 7.13 millimeters are a maximum diameter of the rolling elements. Each row has 13 rollers. A radial play of the bearing is between 0.025 millimeters and 0.04 millimeters. It follows from the diameter of the rollers and the pitch circle diameter that a complete roller set would comprise 17 rollers. The selected 13 rolls thus correspond to a filling level of 76% of the full roll set.The selected combination of bearing features allows for an optimum balance between bearing life, operating performance, and cost under the conditions of this particular application resulting from extensive calculations and testing.FIG. 2 shows an alternative embodiment of a cage 20a of the bearing 10. a side ring 42a has an extension 44a extending radially inwardly. The cage 20 aincludes, on an axially outer end face 22 a, a first surface region 24 awhich is located at a radially inner end 30 aof the end face and which has a smaller axial distance from a center of mass 26 aof the cage than a second surface region 28 aof the end face. In a state where the cage 20 ais assembled into the bearing 10, the end face faces the seal 38. The location of the first surface portion 24a is suitable to provide additional misalignment to the bearing and to prevent the cage from colliding with the seal 38 during misalignment of the bearing. By means of the first surface 24a, a misalignment of the bearing of up to 1 degree is ensured.Figure 3 shows a half-section through a further embodiment of a bearing 10b according to the invention. The only differences compared to the bearing 10 are as follows: the sealing lips of the seals are larger in relation to the bearing rings. The limit rotational speed of the inner ring is 1500 revolutions per minute. The limit rotational speed of the outer ring is 1200 revolutions per minute. The pitch circle diameter of the rows is 47.1 millimeters. The size of the rolling elements is 8.45 millimeters by 7.4 millimeters, wherein the 8.45 millimeters are a maximum diameter of the rolling elements. The maximum radial load of the bearing during operation is 6580 N. The cage of FIG. 2 may also be used for the bearing 10 b(but then with adjusted dimensions).List of reference characters10 Bearing 11 Bearing 12 Outer ring 14 Inner ring 16 Rolling bodies 18 Row 19 Row 20 Cage 21 Cage 22 End face 24 Surface 26 Center of mass 28 Surface area 30 Inner end 32 Roller 34 Belt 36 Intermediate space 38 Seal 40 Seal 42 Lateral ring 44 Extension

Claims

Bearing (10) of a conveying installation having at least one outer ring (12), at least one inner ring (14), rolling bodies (16) which are designed to roll on the outer ring and the inner ring, and lubricant for lubricating movements of the rolling bodies relative to the outer ring and the inner ring, characterized in that the lubricating grease contains molybdenum disulfide.The bearing (10) of a conveyor system according to claim 1, characterized in that the sum of the masses of molybdenum and molybdenum ions in the molybdenum disulfide contained in the grease deviates from 6900 μg per gram of grease by at most 2900 μg per gram of grease.A conveyor bearing (10) according to claim 1 or claim 2, characterized in that a row (18) of the rolling elements (16) of the bearing contains less than 1.05 rolling elements per centimeter of pitch circle circumference of the row.Bearing (10) of a conveyor installation according to at least one of the preceding claims, characterized in that the bearing is a spherical roller bearing which lacks a ring for guidance.Bearing (10) of a conveying installation according to at least one of the preceding claims, characterized in that at least one cage (20) of the bearing is hardened.Bearing (10) of a conveying installation according to at least one of the preceding claims, characterized bya cage (20a) which comprises, on an axially outer end face (22a), a first surface region (24a) which is located at a radially inner end (30a) of the end face and which has a smaller axial distance from a centre of mass (26) of the cage than a second surface region (28a) of the end face.A conveyor bearing (10) according to any preceding claim, characterized in that a maximum radial load of the bearing during operation is 6580 Newtons and / or a maximum axial load of the bearing during operation is 566 Newtons.Bearing (10) of a conveyor installation according to at least one of the preceding claims, characterized in that the grease contains graphite.Bearing (10) of a delivery installation according to at least one of the preceding claims, characterized in that a row (18) of the rolling bodies (16) of the bearing contains between 67% and 87% of the number of such rolling bodies which the row can contain at most.A conveyor system having a bearing (10) according to at least one of the preceding claims, characterized in that the bearing rotatably supports a roller (32) of the conveyor system, wherein the roller movably supports a belt (34) of the conveyor system.

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