Showing papers on "Slewing bearing published in 2021"
TL;DR: Current situation of researches on wind turbine slewing bearing is summarized systematically and failure prediction, monitoring and diagnosis methods of slewing bearings for industries are reviewed and summarized, which can be potentially used for wind energy industry.
64 citations
TL;DR: The above dilemmas are tackled through the in-depth research of symbolic life models: an evolving symbolic regression approach, namely, dynamic structure–adaptive symbolic approach (DSASA), which has reliable generalizations and significantly reduces prediction error.
Abstract: Data-driven technologies, especially artificial intelligence ones, are widely used in residual useful life (RUL) prediction of machinery. They are flexible in predicting RUL without grasping prior ...
21 citations
TL;DR: This study of finite element mesh size verification provides an important guidance for the accuracy and efficiency of carrying capacity of slewing bearings.
Abstract: Slewing bearings are widely used in industry to provide rotary support and carry heavy load. The load-carrying capacity is one of the most important features of a slewing bearing, and needs to be c...
8 citations
TL;DR: In this article, large-diameter slewing bearings of onshore wind turbines made from induction hardened and tempered steel 42CrMo4 are investigated for a more accurate prediction of the service life of slewing bearing under oscillating mode mechanical fatigue test strategies and suitable calculation methods have to be developed.
Abstract: For a more accurate prediction of the service life of slewing bearings under oscillating mode mechanical customized fatigue test strategies and suitable calculation methods have to be developed. In this study large-diameter slewing bearings of onshore wind turbines made from induction hardened and tempered steel 42CrMo4 are investigated. Test samples were cut directly out of the bearing ring (core condition). The orientation of the test cross-section was chosen to corresponding with the presumed most critical orientation of non-metallic inclusions. After sampling three heat treatments were carried out to mimic the different heat treatment conditions of the bearing (raceway, transition region, core). Results of static tests (fracture toughness, tensile strength) and cyclic testing (crack propagation, S-N-curve) were obtained for the three different heat-treated sample batches. The results where correlated to hardness, cleanliness and local residual stresses to develop a deep understanding of crack initiation and crack propagation mechanisms and making a first step towards a more accurate prediction of fatigue life. In order to be able to transfer the analytic results to the real parts, a simulation model will be developed later on.
3 citations
01 Jun 2021
TL;DR: In this paper, three-row roller slewing bearings are the core components of large-scale rotating equipment and a large structural size and heavy load conditions require an extremely high carrying capacity.
Abstract: Three-row roller slewing bearings are the core components of large-scale rotating equipment. A large structural size and heavy load conditions require an extremely high carrying capacity. The inner...
3 citations
TL;DR: This work implements an analytical formulation to simulate the roller-wire-ring subset in a commercial FE software via user-defined matrix element, so that bearing assemblies can be analysed with huge computational cost savings and little convergence problems.
2 citations
12 Oct 2021
TL;DR: In this article, a local finite element model is established to analyze the contact area between the roller and the raceway, and the effect of the mesh size on the offset and the declination of the upper and lower raceway is investigated.
Abstract: Three-row roller slewing bearings are the core components of large-scale rotating equipment. It has a large structural size and is subjected to heavy loads, which requires extremely high carrying capacity. The effect of finite element mesh size on the carrying capacity accuracy of three-row roller slewing bearing is investigated. A local finite element model is established to analyze the contact area between the roller and the raceway, which is compared with the Hertz contact theory to verify the reasonable mesh size of the finite element model. The local spring finite element model is established, and the effect of the mesh size on the offset and the declination of the upper and lower raceway is investigated; The overall finite element model of the slewing bearing is established to analyze the effect of the mesh size and the nonlinear spring stiffness on the carrying capacity accuracy. The whole circle deformation of the ring and the load distribution is investigated to determine the reasonable mesh size. This article provides a method and idea for the verification of the three-row roller slewing bearing finite element model, which is beneficial to improve the calculation accuracy of the bearing capacity of the three-row roller slewing bearing.
2 citations
TL;DR: Slewing bearings are critical components of rotating equipment and large structure sizes and heavy working load conditions require an extremely high load-bearing capacity and reliability as mentioned in this paper. But, they do not have the capacity to handle large structures and heavy load conditions.
Abstract: Slewing bearings are critical components of rotating equipment. Large structure sizes and heavy working load conditions require an extremely high load-bearing capacity and reliability. Overall and ...
2 citations
TL;DR: To determine whether bearing joints were in a good or bad condition, a coefficient of variation and an impulse factor were introduced as diagnostic indicators and it turned out that by evaluating these indicators, it was possible to distinguish between these two conditions.
Abstract: Failure of systems applied in machines comprising rolling and slewing bearings usually causes downtime of the entire heavy machine. The problem of failures can be aggravated by extremely difficult operating conditions, such as significant loads or a harsh environment. The entire issue inspired us to develop a method of monitoring the condition of such units. A study was carried out for six different large-scale excavators which examined strain distributions in the tested subassemblies. In order to estimate the technical condition of wheeled bogies, we used the phenomenon of strain propagation caused by the concentrated force acting in the ring girder web. Flamant theory was utilized to describe this phenomenon. Measurements were performed using strain gauges and the obtained results were compared with the FEM model. To determine whether bearing joints were in a good or bad condition, a coefficient of variation and an impulse factor were introduced as diagnostic indicators. It turned out that by evaluating these indicators, it was possible to distinguish between these two conditions. The method was successfully validated on machines that are in operation.
1 citations
Patent•
09 Mar 2021
TL;DR: In this article, an image acquisition device consisting of a guide disc, an external tooth slewing bearing, a driving mechanism, a cutter side edge and diameter image acquisition mechanism, and a cutter end face image acquisition system is presented.
Abstract: The utility model discloses an image acquisition device and system for cutter state detection, and the technical scheme is that the image acquisition device comprises a guide disc, an external tooth slewing bearing, a driving mechanism, a cutter side edge and diameter image acquisition mechanism, and a cutter end face image acquisition mechanism, the guide disc is installed above the external tooth slewing bearing, and the external tooth slewing bearing is connected with the driving mechanism; the cutter side edge and diameter image acquisition mechanism is connected with the guide disc through a slider-crank mechanism, and the cutter end face image acquisition mechanism is arranged in the center of the guide disc. According to the utility model, images of the rear cutter surface and the attached rear cutter surface of each cutting edge of the cutter can be simultaneously acquired and detected, so that the detection efficiency is improved, and the detection reliability is also ensured.
1 citations
Patent•
07 Apr 2021
TL;DR: In this paper, a wheel steering system consisting of a steering device, a signal execution device, and a steering angle control device is presented, where the steering device is disposed on a steering wheel.
Abstract: A wheel steering system comprises a steering device, a signal execution device, and a steering angle control device. The steering device is disposed on a steering wheel. The steering device comprises a wheel support (2), the top of the wheel support is connected to a chassis (8) by means of a slewing bearing (1), and the bottom of the wheel support is rotatably connected to two ends of a rotary shaft of the steering wheel. The signal execution device controls the slewing bearing (1), so as to control the rotating angle of the steering wheel. The steering angle control device comprises multiple reciprocating switch rotors (9) capable of sending electronic signals of steering angles, and controls, by means of the signal execution device, the steering device to implement steering. The multiple switch rotors (9) are used as the steering angle control device, switches of the switch rotors send electronic signals, and the electronic signals are transferred to the signal execution device. The slewing bearing (1) can turn by 360 degrees, so that a vehicle can have a steering amplitude having a larger angle, and accordingly the steering is more flexible; without a complex mechanical transmission structure, the wheel steering system has a simpler structure. A same technical effect can be achieved on the automobile.
01 Jan 2021
TL;DR: In this paper, the contact relationship between the rolling elements and the raceway is established by establishing a slice model of the slewing bearing, considering the effects of axial load and radial load, respectively.
Abstract: The stability of the rolling elements in the slewing bearing is an important factor that determines the smooth rotation of the slewing bearing. The slewing radius of the slewing bearing is large and the load is complicated. In this paper, the contact relationship between the rolling elements and the raceway is established by establishing a slice model of the slewing bearing. Considering the effects of axial load and radial load, respectively, the contact deformation and displacement changes of the rolling elements are analyzed. The simulation results show that the rolling elements of the two-point contact slewing bearing rotate during the load process, and the four-point contact slewing bearing is in the axial direction. Under load, the rolling contact state in the raceway with the raceway is stable without spinning; under radial load, the contact relationship between the rolling element and the four-point contact raceway at this time is essentially two-point contact, but compared to the one used Two-point contact raceway, the rolling elements have better radial stability in the newly designed raceway
Patent•
29 Apr 2021
TL;DR: In this article, an intelligent slag dragging robot for metal melting, comprising a control cabinet and a slag-dragging mechanism, is presented, where the base is fixed on the ground, the slewing bearing is mounted on the base, and the large arm pull rod support seat is connected to the bottom end of a large arm.
Abstract: An intelligent slag dragging robot for metal melting, comprising a control cabinet (1) and a slag dragging mechanism. The control cabinet is used for controlling the slag dragging mechanism to achieve automatic slag dragging; the slag dragging mechanism comprises a slewing bearing (3) and a base (12); the base is fixed on the ground; the slewing bearing is mounted on the base; the slewing bearing is connected to a large arm pull rod support seat (11); the large arm pull rod support seat is connected to the bottom end of a large arm (5) and that of a pull rod (4); the top end of the large arm is connected to a cross beam (6); the cross beam is connected to a telescopic arm (7); a clamping jaw (8) is mounted at the lower end of the telescopic arm. The intelligent slag dragging robot achieves full-automatic slag dragging, avoids the potential safety hazards of personnel in slag dragging work, and also can reduce the loss of a metal stock solution.
01 Mar 2021
01 May 2021