CN102996745B - The special low speed planet retarder of bearing grease lubrication roller-way - Google Patents

Abstract

The present invention relates to the technical field of reducers in steel mills, and relates to a low-speed planetary reducer for bearing grease lubricated roller tables, which includes a bevel gear pair and a closed-row combination wheel train, and is characterized in that: the journal of the active bevel gear uses two spacers. The first sealed bearing is supported in the inner hole of the front box; the two ends of the input shaft are respectively supported by the second and third sealed bearings in the inner hole of the output shaft and the planet carrier; the planetary wheel is supported on the planetary wheel shaft by two fourth sealed bearings with spacers Above; the quasi-planetary wheel is supported on the quasi-planetary wheel shaft by two fifth sealed bearings with a spacer; the output shaft is supported in the inner hole of the frame by two sixth sealed bearings with a spacer in the middle, and the sixth bearing is installed before Seals. Beneficial effects: the biggest technical effect of the planetary gear box with bearing grease lubrication for rolling bearings and gear oil for gears in the box is that the bearings run reliably, so the reducer has a long service life and low noise.

Description

Special low-speed planetary reducer for bearing grease lubrication roller table

【Technical field】

The invention relates to the technical field of reducers in steel mills, and relates to a special low-speed planetary reducer for bearing grease lubricated roller tables, a gear meshing pair lubricated by gear oil in a frame, and a rolling bearing lubricated by bearing grease.

[background technology] background technology has following two kinds:

(1) "Planetary reducer for roller table" (ZL200710068045.2) is a bevel gear + two-stage planetary system three-stage deceleration structure;

(2) "High-torque planetary reducer for roller table" (201010509647.9) is a two-stage reduction structure of bevel gear + closed combination gear train.

Background Art The main problem is: when the gear oil lubricates the bearing and the gear meshing pair at the same time, the failure rate of the gearbox is high.

The K series spiral bevel gear reducer of SEW company has a high failure rate when it is applied to the rotary brush aerator. In the sewage treatment plant of a leather company in Zhejiang, the aerator is equipped with the K series reducer of Zhejiang ×× reducer company. It broke in less than two months, and it broke again shortly after it was replaced. After disassembling the machine, it was carefully checked and analyzed. The reason is that the bevel teeth are located at the highest point, and the splashed lubricating oil is difficult to lubricate the rolling bearing, which makes the bearing thirsty for oil early, and the cage Broken, the scattered steel balls broke the bevel gear teeth.

"Reducer failures account for about 40% of coal mine equipment failures. Bearings are very easily damaged parts in reducers. Bearing damage forms: bearing scratches, bearing adhesion, bearing intrusion of impurities, bearing cage fracture, etc. Reason: lubrication The high content of large particles and impurities in the oil will increase the wear of the bearing." "Causes and Treatment Methods of Mine Reducer Damage"

"The surface of the load-bearing gear tooth is subjected to different forms of stress. The tooth surface and subcutaneous metal may produce tiny cracks to form a source of fatigue. As the number of stress cycles increases, the cracks will continue to expand and connect to each other to form small pieces of metal. pitting and spalling on the surface, and fatigue damage on the tooth surface of the gear." "Fatigue Damage and Prevention of Tooth Surface of Heavy-duty Gears"

(1) The root cause of the high failure rate of bearings:

"Poor lubrication is the main cause of early failure of bearings" (Liu Zejiu "Rolling Bearing Application Manual" page 891)

"...The early failure of the bearing is often not the fatigue damage caused by the material, but the gradual deterioration of the lubricating grease after the pollutants enter the bearing, which is caused by the indentation on the rolling contact surface." ("Sealing Technology of Sealed Deep Groove Ball Bearings" 》Bearing 2009.05)

The contact stress of the radial ball bearing σmax = 5000Mpa (p.Д. Betelman's "Rolling Bearing Handbook" page 134) is 3-4 times that of the gear pair σmax = 1450Mpa, so the cleanliness of the bearing grease (oil) should be far Lubricant over gears.

(a) On page 103 of "Basics of Mechanical Design" of Shanghai Institute of Mechanical Engineering: "After the gear transmission equipment has been used for a period of time, it can be found that there are wear marks on the surface of the gear teeth, especially under the conditions of poor lubrication or impure lubricating oil. It is more obvious that the root of the tooth is more severely worn than the top, and the pinion is more severely worn than the gear. The wear is caused by the force and relative sliding between the contact surfaces. There is a relative sliding length ΔS between the tooth profiles, indicating that the teeth Outlines are going to wear out."

(b) Page 94 of Zhu Xiaolu's "Gear Transmission Design Manual": In power gear transmission, tooth surface loss is inevitable due to sliding wear, corrosion, overheating, etc. on the surface of the gear teeth;

(2) In theory, the bearings are required to be lubricated with grease (or mineral oil without additives), and the gears are lubricated with additives:

(a) Liu Zejiu's "Rolling Bearing Application Manual" page 893: "When bearings operating at high speeds or at high temperatures cannot be lubricated with grease or when the parts adjacent to the bearing (such as gears) are lubricated with lubricating oil, the bearings are lubricated. Grease."

Page 921: "...The lubrication of rolling bearings generally uses mineral oil without additives";

(b) Page 1087 of Zhu Xiaolu's "Gear Transmission Design Manual": For gears under boundary lubrication, lubricating oil containing extreme pressure antiwear agents (additives) should be used.

The kinematic viscosity of SH/T0017-1990L-FC first-class bearing oil is 90-100; it is much smaller than the gear oil viscosity of 288-352.

Conclusion: The root cause of the high failure rate of gearboxes and bearings is that the gears and rolling bearings are lubricated with gear oil at the same time.

[Content of the invention] The object of the present invention is to provide a low-speed planetary reducer dedicated to bearing grease lubricated roller tables with long service life.

[Technical solution] The journal of the active bevel gear is supported in the inner hole of the front box by two first sealed bearings with spacers; the two ends of the input shaft are respectively supported by the second and third sealed bearings in the inner hole of the output shaft and the planet carrier; The wheel is supported on the planetary wheel shaft by two fourth sealed bearings with spacers; the quasi-planetary wheel is supported on the quasi-planetary wheel shaft by two fifth sealed bearings with spacers; the output shaft is supported by two fifth sealed bearings with spacers in the middle Six sealed bearings are supported in the inner hole of the machine base, and a seal is installed before the sixth bearing.

The sealed bearing is a contact radial sealed bearing, such as RK, or RS, or HMS (A), or MHS (A) type, and the seal is a rotating shaft lip seal, or a combination seal.

Feasibility statements for grease lubricated bearings are as follows:

①Essmann's "Rolling Bearing Design and Application Manual" page 221: "When the structure is compact, it is best to use a radial ball bearing with double-sided seals. The radial ball bearing with double-sided seals has been loaded enough for the entire bearing Grease with an expiry date."

②Bu Yan's "Practical Bearing Technical Manual" page 95: "In those places where the structure is compact, the axial size requirements are small, the sealing requirements are strict, the maintenance and oil replenishment are difficult, and it is inconvenient to use additional sealing devices, sealed bearings can be preferred."

③ Liu Zejiu's "Rolling Bearing Application Manual" page 593: "The sealed bearing can not only have a good sealed lubrication environment, but also save the complicated lubrication system. Therefore, it is recommended to use sealed bearings in the parts with compact structure and strict sealing requirements."

Zhu Xiaolu's "Gear Transmission Design Manual" page 1096: "Gear lubricating oil has its service life just like gears and other parts, and the service life of oil products is closely related to the working conditions and maintenance technology. ... Normal operation of general industrial gears The oil must be changed every 2500h. or 6 months.” Liu Zejiu’s “Rolling Bearing Application Manual” page 913: The empirical formula for the grease change cycle is as follows:

T＝1.475·10 ⁶ K ^-0.9908 -1.025·10 ⁶ K ^-0.8626 (h.)

In the formula: coefficient K=K _f n Dm(r mm/s) (ball bearing K _f =0.9-1.1), Dm=(D+d)/2

Calculation results: the grease change cycle of the sealed bearing is greater than the specified 2500 (h.) grease change cycle, thus proving that the sealed bearing has been filled with enough grease for the entire service life of the bearing.

Motor n ₁ =1000rpm, NAD: i=6.3, n=158.7rpm, NBD: i=40, n=25rpm grease change cycle

[Beneficial effects] The technical effect is that the bearing runs reliably, so the reducer has a long service life and low noise.

[Description of drawings] Figure 1. Structural schematic diagram of an embodiment of the present invention

[Specific embodiments] The present invention will be described in detail below in conjunction with the accompanying drawings:

Refer to Figure 1. A low-speed planetary reducer dedicated to bearing grease lubricated roller tables, including the main frame 5, the differential element and alignment planetary elements in the main frame 5, the auxiliary frame 1 and the bevel gear installed in the auxiliary frame 1 pair, the differential element includes the input shaft 2, the first sun gear 8 coupled to the input shaft 2, the planetary gear 11, the planet carrier 20 and the ring gear 12, and the alignment planetary element includes the second sun gear 9, The quasi-planetary gear 13, the quasi-planetary wheel shaft 15, the fixed frame 4 and the ring gear 12, the second sun gear 9 is sleeved on the input shaft 2, one end of the quasi-planetary wheel shaft 15 is fixed on the fixed frame 4, and the The involute splines in the planet carrier 20 mesh with the second sun gear 9, the differential element and the alignment planetary element share an inner ring gear 12, and the inner ring gear 12 is connected to the output shaft 7 as a disk, so Said auxiliary base 1, fixed frame 4 and main base 5 are sequentially connected together, and said bevel gear pair comprises driving bevel gear 16, driven bevel gear 17, and said driven bevel gear 17 is connected to the input end of input shaft 2, It is characterized by:

The journal of the driving bevel gear 16 is supported in the inner hole of the sub-frame 1 by two first sealed bearings 18 with spacers;

The top end of the input shaft 2 is supported in the inner hole of the output shaft 7 by the second sealed bearing 19, and the inner hole of the fixed frame 4 is supported by the third sealed bearing 3 near the driven bevel gear 17;

The planet wheel 11 is supported on the planet wheel shaft by two fourth sealed bearings 10 with spacers;

The quasi-planetary wheel 13 is supported on the quasi-planetary wheel shaft 15 with two fifth sealed bearings 14 with spacers;

The output shaft 7 is supported in the inner hole of the main base 5 by two sixth sealed bearings 6 with spacers in the middle, and a seal 21 is installed before the two sixth sealed bearings 6;

All sealed bearings are contact radial sealed bearings;

The seal is a rotary shaft lip seal, or a car's combined seal (Cheng Daxian's "Mechanical Design Manual" volume 3-10-269, page 300).

"The self-sealing of the bearing is divided into contact type and non-contact type according to the structure. According to the contact type, it can be divided into radial seal and axial seal. According to the structure of the sealing ring, it can be divided into single lip seal and double lip seal." ( Liu Zejiu "Rolling Bearing Application Manual" page 593)

The embodiment is an illustration rather than a limitation to the present invention, and any scheme after simple transformation belongs to the protection scope of the present invention.

Claims (1)

1. the special low speed planet retarder of bearing grease lubrication roller-way, comprise main machine base (5), differential in main machine base (5) and quasi-planet part, auxiliary engine bed (1) and the bevel gear pair be contained in auxiliary engine bed (1), described differential comprises input shaft (2), be connected in the first sun gear (8) on input shaft (2), planet wheel (11), planet carrier (20) and ring gear (12), described quasi-planet part comprises the second sun gear (9), there won't be any problem star-wheel (13), quasi-planet wheel shaft (15), fixing frame (4) and ring gear (12), described second sun gear (9) empty set is on input shaft (2), described quasi-planet wheel shaft (15) one end is fixed on fixing frame (0), described planet carrier (20) interior involute splines engages with the second sun gear (9), described differential shares a ring gear (12) with quasi-planet part, described ring gear (12) connects with output shaft (7) disk, described auxiliary engine bed (1), fixing frame (4) and main machine base (5) are integrally togather in turn, described bevel gear pair comprises drive bevel gear (16), driven wheel of differential (17), described driven wheel of differential (17) is connected in input shaft (2) input end, it is characterized in that:

Described drive bevel gear (16) axle journal is bearing in auxiliary engine bed (1) endoporus with there being two of spacer ring the first stuffing box bearings (18);

Described input shaft (2) top the second stuffing box bearing (19) is bearing in output shaft (7) endoporus, and is bearing in fixing frame (4) endoporus near driven wheel of differential (17) place with the 3rd stuffing box bearing (3);

Described planet wheel (11) is bearing on planet wheel shaft with there being two of spacer ring the 4th stuffing box bearings (10);

Described there won't be any problem star-wheel (13) is bearing on quasi-planet wheel shaft (15) with there being two of spacer ring the 5th stuffing box bearings (14);

Described output shaft (7) centre has two of spacer ring the 6th stuffing box bearings (6) to be bearing in main machine base (5) endoporus, before described two the 6th stuffing box bearings (6), Sealing (21) is housed;

Whole stuffing box bearing is contact-type radial seal bearing, and Sealing is rotary shaft lip seal or Che Shi combination seal.