Improvement in hub and shaft assembly for agricultural machines

Description

1 / 7 IMPROVEMENT IN HUB AND SHAFT ASSEMBLY FOR AGRICULTURAL MACHINES Scope of Application of the Utility Model

[01] This utility model relates to an improvement in the hub and shaft assembly for planter rows, belonging to the field of agricultural mechanics, more specifically to the rotation and support components used in seeding mechanisms. The proposed model aims to provide greater durability, reduced maintenance needs and increased operational efficiency of the assembly, by introducing a double dust sealing system, consisting of an O-ring and front cover and, at the rear, a seal and grease arranged between the shielded bearing and the seal.

[02] This new assembly design incorporates a rear containment cover that prevents the seal from being expelled during the lubrication process, which is carried out every 250 hours of work or at the end of the planting cycle. Background of the Utility Model

[03] Modern agricultural machinery uses hub and axle assemblies responsible for supporting and rotating the limiting wheels and seed metering devices. These components operate in harsh environments, subject to the constant presence of dust, abrasive particles and moisture, which requires efficient sealing and lubrication systems to ensure good performance and durability of the equipment. Traditionally, the assemblies used in planting rows employ open or shielded bearings, both of which have significant limitations regarding protection against external contaminants. Petition 870250107070, dated 11 / 24 / 2025, page 5 / 22 2 / 7

[04] In systems that use open bearings, sealing is achieved only by applying grease, requiring daily lubrication to prevent dust ingress and consequent deterioration of the assembly. This practice demands significant maintenance time and high grease consumption, as well as requiring constant labor, since each planting row may contain multiple lubrication points. This need for frequent maintenance negatively impacts productivity and increases the operational costs of agricultural activities.

[05] On the other hand, the use of shielded bearings has been adopted as an alternative to reduce maintenance. However, it is observed that, under field conditions, the shielding does not guarantee total sealing against the entry of dust and moisture. With the accumulation of abrasive particles, the bearings seize and consequently break during planting, resulting in unforeseen stoppages, loss of time and additional costs for replacing parts. This problem highlights the inadequacy of conventional sealing systems available on the market.

[06] Given these limitations, the need arose for a hub and shaft assembly with improved sealing, capable of ensuring effective protection against dust ingress and significantly reducing lubrication frequency. The present utility model was developed with the aim of solving these deficiencies, by means of a double protection system, combining mechanical and chemical sealing, which increases the service life of the assembly, reduces component wear and provides greater reliability and operational efficiency in planter lines. Petition 870250107070, dated 11 / 24 / 2025, page 6 / 22 3 / 7

[07] Several developments related to hub and axle assemblies applied in agricultural machinery are found in the state of the art.

[08] Document WO2002019791A1, owned by VaderstadVerken AB, describes a disc for agricultural machinery that rests on a flange formed in the hub, featuring a recess with an inclined radial wall that partially accommodates the flange and connects the disc to the hub. Although this solution provides an efficient structural coupling between the disc and the hub, it does not address the problem of sealing against dust and external contamination, a critical factor in agricultural operations, nor does it propose improvements to the lubrication or maintenance system.

[09] Document BRPI1105986B1, from Semeato S / A, discloses a double-sealed hub for use in agricultural machinery and implements. The assembly consists of a bearing mounted on an internal shaft and secured by a snap ring, also including an O-ring and a crush-proof seal cover, as well as a protective cover with grease and a metal pressure seal. Although the system provides a degree of protection against the ingress of impurities, the metal pressure seal tends to be sensitive to deformation and does not guarantee complete tightness under high dust load conditions. Furthermore, the design does not include mechanisms to retain the seal during lubrication, which may cause it to be expelled during prolonged use.

[010] Document BRPI1105612B1, from Randon S / A, describes a hub assembly equipped with two roller bearings, separated by an elastic spacer arranged axially between the inner rings of the bearings. This configuration aims to reduce failures and extend the life of the bearings. Petition 870250107070, dated 11 / 24 / 2025, p. 7 / 22 4 / 7 longer bearing lifespan, facilitating disassembly and maintenance of the assembly. However, the solution focuses on stress relief and mechanical adjustments of the hub, without including an improved sealing system to prevent the entry of dust and moisture, an essential aspect in agricultural applications.

[011] Finally, document BR102012030914B1, authored by Ademar Birck, discloses a shaft composed of grooved cylindrical sections, allowing lubricant insertion through perforated internal cavities. Although it presents advantages in terms of lightness and lubricant economy, the model is not intended to solve mechanical and chemical sealing problems in the hub and shaft assembly. Furthermore, the perforated structure, while facilitating grease flow, does not prevent dust from entering the moving parts, compromising field performance. Thus, it is observed that, despite known solutions seeking to increase durability and reduce maintenance, none of them presents an effective double protection system against dust combined with a retainer containment mechanism during lubrication, as proposed in the present utility model.

[012] In view of the foregoing, it is clear that the solutions known in the state of the art, although presenting specific advances in terms of structural coupling, partial sealing or stress relief, do not fully solve the problems of dust contamination, seal expulsion and the need for frequent lubrication in hub and shaft assemblies used in planter lines. Thus, the present utility model proposes a constructive improvement that combines double mechanical and chemical sealing, coupled with a seal containment mechanism and optimization of the lubrication cycle, resulting in a more durable, reliable and Petition 870250107070, dated 11 / 24 / 2025, page 8 / 22 5 / 7 reduced maintenance, meeting the performance and robustness requirements of the agricultural sector. Utility Model Summary

[013] These features promote greater efficiency and better sealing when compared with prior art documents.

[014] The utility model features a double dust seal system, consisting of an O-ring and a front cover, which ensures total mechanical sealing at the front of the assembly, preventing the entry of impurities and eliminating the need for daily lubrication.

[015] A feature of the utility model is a rear retainer combined with a grease chamber, positioned between the shielded bearing and the retainer, forming a chemical sealing barrier that keeps the bearing continuously lubricated and protected against external contaminants.

[016] A feature of the utility model is a rear containment cap, arranged to prevent displacement or expulsion of the retainer during grease application, ensuring the stability of the sealing elements and preventing failures due to internal overpressure.

[017] The utility model features an optimized lubrication system that allows for extended maintenance intervals — every 250 hours of work or at the end of the planting cycle — significantly reducing grease consumption, downtime, and operating costs.

[018] The utility model features a hub and shaft assembly of high durability and reliability, designed to operate in environments with high dust levels and variable loads, providing Petition 870250107070, dated 11 / 24 / 2025, p. 9 / 22 6 / 7 longer component lifespan, less wear and tear, and superior efficiency in agricultural planter lines. Description of the Drawings

[019] Figure 1 shows a perspective view of the cube and shaft assembly.

[020] Figure 2 shows the side view of the cube and shaft assembly.

[021] Figure 3 shows the rear perspective view of the cube and shaft assembly.

[022] Figure 4 shows the front view of the cube and shaft assembly.

[023] Figure 5 shows a cross-sectional view of the hub and shaft assembly.

[024] Figure 6 shows an exploded view of the cube and shaft assembly, detailing its construction. Detailed Description of the Utility Model

[025] The improved hub and shaft assembly for agricultural machinery, the subject of this utility model, comprises an assembly (100) equipped with a hub (10) and shaft (20) with a double dust protection system, with a mechanical system at the front with an O'ring (11), cover (12) and a seal (13) at the rear with grease between the shielded bearing (14) and the seal (13).

[026] An adapter (15) is placed on the rear portion to prevent the retainer (14) from being ejected from the housing during lubrication.

[027] The hub (10) is fitted with a grease fitting (16) which allows grease to be placed on the rear of the bearing (14) for chemical sealing. Lubrication is carried out every 250 working hours or at the end of the planting cycle if the total number of hours is not reached.

[028] The front cover (12) is fixed to the hub (10) by means of screws (121) which allow the assembly to be shielded together with the ring (11). Petition 870250107070, dated 11 / 24 / 2025, p. 10 / 22 7 / 7

[029] The base (10) has a set of holes (10A) that serve to fix machine elements, such as: cutting discs, covering wheels and wheel rims. These holes (10A) are only one of the possible variables, as they will change depending on the machine model and the application of the assembly. Petition 870250107070, dated 11 / 24 / 2025, p. 11 / 22

Claims

1 / 1 CLAIMS:

1. IMPROVEMENT IN HUB AND SHAFT ASSEMBLY FOR SEED DRILL ROWS which presents an assembly (100) provided by hub (10) and shaft (20), characterized by having an O'ring (11) and a cover (12) fixed to the hub (10) by means of screws (121), at the rear a retainer (13) provided with grease between it and a shielded bearing (14), said hub (10) provided with grease fitting (16) which allows the insertion of grease into the rear part of the bearing (14), establishing a complementary chemical seal.

2. IMPROVEMENT IN HUB AND SHAFT ASSEMBLY FOR SEED DRILL ROWS, according to claim 1, characterized by comprising an adapter (15) positioned on the rear portion of the hub (10), configured to prevent the seal (13) from being ejected from the housing during lubrication.

3. IMPROVEMENT IN HUB AND SHAFT ASSEMBLY FOR SEED DRILL ROWS, according to claim 1, characterized in that the base of the hub (10) has a set of holes (10A) intended for fixing elements of agricultural machinery, wherein the dimensions and positions of the holes (10A) vary according to the model and application of the machine. Petition 870250107070, dated 11 / 24 / 2025, p. 12 / 22

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