Residential Sectional Garage Door
A typical version of an overhead garage door used in the past would have been built as a one-piece panel.The panel was mounted on each side with unequal parallelogram style hinge lifting mechanism. Newer versions of overhead garage doors are now generally built from several panels hinged together that roll along a system of tracks guided by rollers. The door is balanced by either a torsion spring system or a pair of extension springs.A remote controlled motorized mechanism for opening garage doors adds convenience, safety, and security
• Aluminum garage doors are low-cost, light, rust-proof, and feature low-maintenance. They are prone to denting because aluminum is not strong and they are energy-inefficient since aluminum is a highly conductivematerial.
• Fiberglass and vinyl garage doors are composite units, combining a steel core behind a fiberglass or vinyl skin. They have also polyurethane insulated base sections, or other type of foam insulation. These premium doors can match steel garage doors, and be a realistic imitation of wood (namely fiberglass units), but they may be more expensive than steel units.
• Steel doors have become common and are available in a variety of sizes and styles, provide strength and security, are cost-competitive, and may have optional insulating value. Extra strength is available with two or three layers of galvanized steel with a low gauge number (23-24 gauge steel panels).
• Wood garage doors offer aesthetic appeal, but they are high-maintenance and may be expensive. Low-priced wood garage doors may warp and break easily.
Residential Sectional Garage Door,Automatic Metal Sectional Garage Door,Standard Lift Garage Door Drum,Polyurethane Foam Garage Door Shenzhen Hongfa Automatic Door Co., Ltd. , https://www.spiralfastdoor.com
/*728*90 created on 2018/5/16*/ var cpro_id = "u3440131"; Home>Bearing knowledge>The cause of failure of NTN bearing and its adoption The cause of failure of NTN bearing and its adoption
When the NTN bearing is pressed into the elliptical housing hole or the two halves are fastened; the bearing outer ring is elliptical; the clearance in the short axis direction is significantly reduced or even negative. The bearing is under load. The inner ring rotates with circumferential shedding marks; the outer ring only shows signs of shedding in the symmetrical orientation of the short axis; this is the primary cause of the early failure of the bearing. The bearing trading network teaches the bearing failure parts to be inspected; the NTN bearing The outer diameter roundness has been changed from 0. 8μm to 27μm controlled by the original process; this value is much larger than the radial clearance value. /*250*250 was created on 2017/12/25*/ var cpro_id = 'u3171089';
Therefore, the bearing trading network operator can certainly operate the NTN bearing under severe deformation and negative clearance; the working surface is easy to form an abnormally sharp wear and fall early; the adopted countermeasure is to improve the machining accuracy of the outer casing hole or not The two sides of the shell hole are selected from the layout. The raceway is slanted off and the belt is slanted off the bearing belt; the bearing is operated under the skew condition; when the slant angle reaches or exceeds the critical condition; The reason for the occurrence is that the device is poor, the shaft has deflection, and the accuracy of the journal and the shell hole is lower. The countermeasures are adopted to ensure the quality of the NTN bearing device and the axial runout accuracy of the shoulder and the shoulder. Professor Net for us to describe the type of bearing is a small form and the corresponding adoption method.
a. Abnormal load of the cage. If the device is not in place, skewed, excessive interference is easy to form clearance reduction; increase conflict heat generation; appearance softening; premature occurrence of abnormal shedding; followed by the expansion of shedding; shedding foreign matter into the cage pocket Incurs the cage operation block and additional load; the wear of the cage is aggravated; the deterioration of the cycle effect; the cage crack can be formed.
b. The poor smoothness mainly means that the NTN bearing operation is in a lean state; it is easy to form adhesive wear; the appearance of the work is deteriorated; the tearing material caused by adhesive wear is easy to enter the cage; the cage is subjected to an abnormal load; and the cage can be cracked.
c. The intrusion of foreign objects is a common form of cracking failure of the cage. The intrusion of foreign hard foreign objects increases the wear of the cage and the abnormal additional load; it can also cause the cage to crack.
d. The creep appearance is also one of the reasons for the cracking of the cage. The so-called creep multi-finger slewing surface; in the case of lack of interference in the cooperation surface; the load point moves in the surrounding direction because of the sliding; The appearance of the shaft or the casing facing away from the circumferential direction. Once the creep occurs, the cooperating surface is obviously worn; the wear powder has the ability to enter the inside of the NTN bearing; the process of forming the abnormal wear and rolling off the cage wear and the additional load; so that the cage can be constructed Cracking.
e. Disadvantages of cage data (such as cracks, large foreign metal inclusions, shrinkage cavities, air bubbles) and riveting defects (nails, studs or two halves of the cage contact surface; severe riveting) can constitute cage cracking Adopting countermeasures is to strictly control the production process.
Recommend to friends comments close window Bearing related knowledge The common sense of bearing entry is different. The characteristics of plastic bearing bearing characteristics of the bearing and the countermeasures to analyze the abnormal damage of the hub bearing. Analysis of the use of metal self-correction data on the bearing (1)
This article links to http://
Please indicate the bearing network http://
Previous:Analysis: Description of stainless steel deep groove ball bearing Next: What are the sliding bearings?
The cause of failure of NTN bearing and its adoption
Source: China Bearing Network Time: 2014-09-19