The three-row column slewing bearing for construction machinery specified in this standard is a special force transmission basic component in construction machinery that simultaneously bears axial force, tipping moment, radial force and requires two parts to rotate relative to each other. This standard specifies the mechanism type, basic parameter series, technical requirements, test methods and inspection rules of the three-row column slewing bearing. This standard is applicable to the product design, manufacture and selection of three-row column slewing bearings. Other lifting and loading machinery, mining machinery, port machinery, etc. can also refer to it. JG/T 68-1999 Three-row column slewing bearing for construction machinery JG/T68-1999 Standard download decompression password: www.bzxz.net

ICS91.220
(Original)JG 68-1999
Construction Industry Industry Standard of the People's Republic of ChinaJG/T 68—1999
Construction machinery 3-row roller slewing rings1999-06-04 Issued
Issued by the Ministry of Construction of the People's Republic of China
Implemented on 1999-06-04
JG/T68—1999
According to the State Administration of Quality and Technical Supervision's "Notice on the Abolition of Professional Standards and National Standards to be Transformed after Cleaning Up and Rectification" [Quality and Technical Supervision Bureau Standard Letter (1998) No. 216], the Ministry of Construction has cleaned up, rectified and reviewed the national standards approved by the State Administration of Technical Supervision in 1992 for the Ministry of Construction to be converted into industry standards and the product standard projects approved and issued by the Ministry of Construction before 1992. The Ministry of Construction confirmed and issued the standard JJ36.3-91 "Three-row column slewing bearing for construction machinery" with the document No. 154 of Jianbiao (1999) "Notice on the Announcement of the Results of the Cleaning and Rectification of the Product Standards of the Ministry of Construction", and the new number is JG/T681999. In order to facilitate the implementation of the standard, only the cover, first page, and the above-margin statement of the original standard are modified accordingly, and reprinted after adding this explanation, and the original standard version is abolished at the same time. Construction Industry Standard of the People's Republic of China Construction Machinery Three-row slewing bearing
Constructionmachinery3-rowrollerslewingringsJG/T68-1999
The three-row column slewing bearing for construction machinery specified in this standard (hereinafter referred to as the three-row column slewing bearing) is a special force transmission basic component in construction machinery that simultaneously bears axial force, tipping moment, and radial force and requires two parts to rotate relative to each other. 1 Subject content and scope of application
This standard specifies the structural type, basic parameter series, technical requirements, test methods and inspection rules of three-row column slewing bearings. This standard is applicable to the product design, manufacture and selection of three-row column slewing bearings. Other lifting and loading machinery, mining machinery, port machinery, etc. can also be used as a reference.
2 Reference standards
GB1299
GB1356
GB3077
High-quality carbon structural steel grades and general technical conditions Technical conditions for alloy tool steel
Base tooth profile for involute cylindrical gears
Technical conditions for alloy structural steel
GB3480
GB4429
GB4661
GB5782
GB6170
GB6172
GB6175
GB10095
HG2-869
HG4-32 9
Mechanical properties of fasteners Mechanical properties of bolts, screws and studs Nuts
Calculation method of load-bearing capacity of involute cylindrical gears Aluminum bronze rods
Rolling bearings
Cylindrical rollers
Hexagonal head bolts Grade A and B
Type 1 hexagonal nuts Grade A and B
Hexagonal thin nuts Grade A and B chamfering
Type 2 hexagonal nuts Grade A and B
Precision of involute cylindrical gears
Polyamide 1010 resin
Sealing rubber productsWww.bzxZ.net
3 Structural types and basic parameter series
3.1 The structural type of three-row column slewing bearings shall comply with those shown in Figures 1 and 2. 3.1.1 According to the gear transmission mode, it is divided into:
-external tooth type (see Figure 1);
bN-internal tooth type (see Figure 2).
Approved by the Ministry of Construction of the People's Republic of China on June 4, 1999 and implemented on June 4, 1999
d,(m,z,x)
d,(m,z,x)
JG/T68—1999
Figure 1SW structural type
dr(m,z,x)
dt(m,z,x)
JG/T68—1999
ds(m,z,x)
dr(m, z, x)
Figure 2SN structure type
3.1.2 According to the installation connection hole type (see Figure 1, Figure 2), it is divided into: aA type - both inner and outer ring installation holes are through holes; bB type -
- both inner and outer ring installation holes are screw holes:
cC type - the outer ring installation hole is a screw hole, the inner ring installation hole is a through hole; dD type - the outer ring installation hole is a through hole, the inner ring installation hole is a screw hole. 3.1.3 Rolling element combination
Rolling element diameter matching:
d(m,z,x)
dr(m, z,x)
Upper row rolling element diameter/lower row rolling element diameter/vertical row rolling element diameter (mm): 20/16/12, 25/20/16, 32/25/20, 40/32/25, 50/40/25.
The diameter of the upper row of rolling elements is the nominal diameter do of each group of rolling elements. 3.2 The model of the three-row column slewing bearing should be marked as follows. 3
Marking example:
JG/T68—1999
Nominal diameter of rolling element, mm
Center diameter of main raceway, mm
Installation connection hole type code
Gear transmission type code
Three-row column slewing bearing code
a. Three-row column slewing bearing, external gear type, outer ring screw hole and inner ring through hole connection, main raceway center diameter 1250mm, rolling Body combination 20/16/12:
slewing bearing SWC1250.20JG/T68--1999b. Three-row column slewing bearing, internal gear type, inner and outer ring screw connection, main raceway center diameter 2000mm, rolling element combination 25/20/16:
slewing bearing SNB2000·25JG/T68-19993.3 The basic parameter series of three-row column slewing bearing shall comply with the provisions of Table 1 and Table 2. 3.4 The original tooth profile of the gear in this standard is the reference tooth profile specified in GB1356: tooth profile angle α=20°, working tooth height h=2m, tooth pitch P=yuanm, radial clearance C=0.25m, tooth root fillet radius pt=0.38m. For special requirements of internal gear type, short tooth profile is allowed, and its original tooth profile shall comply with the provisions of short teeth in GB1356. 3.5 Isolation blocks should be placed between the rollers of the three-row column slewing bearing. The width of the isolation blocks between the upper and lower rows of rollers should comply with the provisions of Table 3, and the width of the isolation blocks between the vertical rows of rollers should comply with the provisions of Table 4. 3.6 There should be enough lubricating oil filling oil cups for the three-row column slewing bearing. The position of the oil cups on the cross section of the slewing bearing is shown in Figure 1 and Figure 2. The spacing of the oil cups in the circumferential direction of the slewing bearing should be selected between 800 and 1600 mm. 4 Technical requirements
4.1 Rollers
The roller material is GCr15 or GCr15SiMn and complies with the provisions of GB4661. The roller grades used in this standard are shown in Table 5. 4.2 Ring materials and rough parts
4.2.1 The materials of each ring shall be 50Mn, 42CrMo, 45MnV, 50MnV, 5CrMnMo or other materials with equivalent properties in accordance with GB699, GB1299 and GB3077. 4.2.2 There shall be no white spots on the rough parts surface, and no surface and internal cracks; non-metallic inclusions of sulfides shall not exceed level 2.5; oxides shall not exceed level 3; and the grain size shall be higher than level 6. For rough parts treated by quenching and tempering after hot rolling, the hardness is HB231~286. 4.3 Isolation blocks
The isolation block materials shall be No. 20 steel in accordance with GB699; QA110-3-1.5 in accordance with GB4429; polyamide 1010 resin in accordance with HG2-869; and cracks are not allowed in the isolation blocks. 4.4 The sealing strip is made of oil-resistant rubber conforming to HG4-329, and its hardness is not less than Shore A70. 4.5 Heat treatment requirements
JG/T68—1999
—1999
0662288
2802216
OS000SMS
oossms
280082
JG/T68—1999
JG/T68-1999
OS000SNS
OS0SNS
OSs NS
JG/T68—1999
4.5.1 Three-row column slewing bearings are divided into superior, first-class and qualified products according to the heat treatment quality of rollers, raceways and teeth. Width of the isolation block between the upper and lower rows of rollers
Roller diameter
Isolation width b
Roller diameter
Isolation width bl
Roller diameter d. , mm
The variation of roller diameter in each set should be less than, um4.5.2· Roller surface hardness see Table 6.
Width of isolation block between vertical rows of rollers
Roller grade
4.5.3 Each raceway shall be surface quenched, and its surface hardness is shown in Table 6; the depth of the rate hardening layer shall comply with the provisions of Table 7; one tempering zone is allowed, and the width of the tempering zone shall comply with the provisions of Table 7, and each ring shall be marked with "√√√" or other obvious marks at the tempering zone on the exposed surface; there shall be no cracks visible to the naked eye on the raceway surface. 4.5.4 The gear part can be surface quenched or tempered. When the gear is quenched, the surface hardness of the gear is shown in Table 6. The depth of the hardened layer at the root of the tooth is 1.02.5mm, and the depth of the hardened layer on the tooth surface is 1.5~3.2mm. The depth of the hardened layer increases with the increase of the gear module. 4.6 After the three-row column slewing bearing is assembled, its axial clearance, radial clearance and relative runout of the inner and outer rings shall comply with the provisions of Table 8; the contact length between its rolling element and the raceway shall comply with the provisions of Table 9. Product quality grade
Roller hardness, ≥
Raceway surface hardness, ≥
Surface hardness when the gear is quenched, ≥
Note: ① At least 6 points are evenly distributed on each raceway. Heat treatment hardness
Superior product
The hardness of the tooth surface is measured at the circumference of 6 teeth evenly distributed. First-class products
Depth of hardened layer on raceway surface and width of tempered zone Table 7
Roller diameter d.
Depth of hardened layer, 》
Superior products
First-class products
Qualified products
Width of tempered zone B, ≤
Note: ①Depth of hardened layer refers to the distance from the surface to the point where the hardness is HRC 44. 25
②Width of tempered zone B refers to the distance between the middle of the raceway at both ends of the tempered zone where the hardness is HRC50. 32
Qualified products
Gear accuracy, etc. should comply with the provisions of GB10095. It is recommended that the finished gear accuracy level should be 998GJ or 10109FH. 4.7
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