JB/T 8878-2011 English PDF (JBT8878-2011)

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JB/T 8878-2011: Rolling bearings. Drawn cup needle roller bearings. Specifications
JB/T 8878-2011
JB
MECHANICAL INDUSTRY STANDARD
OF THE PEOPLE’S REPUBLIC OF CHINA
ICS 21.100.20
J 11
Registration number. 34884-2012
Replacing JB/T 8878-2001
Rolling bearings - Drawn cup needle roller bearings -
Specifications
ISSUED ON. DECEMBER 20, 2011
IMPLEMENTED ON. APRIL 01, 2012
Issued by. Ministry of Industry and Information Technology of PRC
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative references ... 4 
3 Terms and definitions ... 5 
4 Symbols (see Figure 1) ... 5 
5 Technical requirements ... 6 
5.1 Materials and heat treatment ... 6 
5.2 Tolerance ... 6 
5.3 Others ... 7 
6 Testing methods ... 7 
7 Inspection rules ... 8 
8 Markings ... 8 
9 Anti-rust packaging ... 8 
Appendix A (Informative) Technical requirements for shafts and housing bores
matched with bearings ... 9 
A.1 Shaft matched with the bearing ... 9 
A.2 Housing bores matched with the bearing ... 9 
Appendix B (Informative) Recommended installation method ... 10 
Rolling bearings - Drawn cup needle roller bearings -
Specifications
1 Scope
This standard specifies the technical conditions for general purpose non-inner
ring and drawn cup needle roller bearings (hereinafter referred to as bearings)
which comply with the provisions of GB/T 290-1998 and GB/T 12764-2009.
This standard applies to the production, inspection and acceptance of bearings.
2 Normative references
The following documents are essential to the application of this document. For
the dated documents, only the versions with the dates indicated are applicable
to this document; for the undated documents, only the latest version (including
all the amendments) are applicable to this standard.
GB/T 290-1998 Rolling bearings - Needle roller bearings, drawn cup without
inner rings - Boundary dimensions
GB/T 307.2-2005 Rolling bearings - Measuring and gauging principles and
methods
GB/T 1957-2006 Tolerances and general features for plain limit gauges
GB/T 4199-2003 Rolling bearings - Tolerances - Definitions
GB/T 4340.1-2009 Metallic materials - Vickers hardness test - Part 1. Test
method
GB/T 5213-2008 Cold rolled low carbon steel sheet and strip
GB/T 6930-2002 Rolling bearings - Vocabulary
GB/T 7811-2007 Rolling bearings - Symbols for quantities
GB/T 8597-2003 Rolling bearings - Rust proof packaging
GB/T 12764-2009 Rolling bearings - Needle roller bearings, drawn cup
without inner ring - Boundary dimensions and tolerances
GB/T 24605-2009 Rolling bearings - Marking for products
Appendix A
(Informative)
Technical requirements for shafts and housing bores matched with
bearings
A.1 Shaft matched with the bearing
A.1.1 The hardness of the journal’s fit surface is not less than 58 HRC.
A.1.2 The maximum surface roughness of the journal’s fit surface is Ra0.2 μm.
A.1.3 The journal has a dimensional tolerance of h5 (h6).
A.1.4 The cylindricity of the journal’s fit surface shall not exceed 50% of the
dimensional tolerance of the shaft.
A.2 Housing bores matched with the bearing
A.2.1 The maximum surface roughness of the fit surface of the housing bore is
Ra0.8 μm.
A.2.2 Dimensional tolerance of the housing bore is selected according to the
material of the seat based on Table A.1.
Table A.1
Materials of bearing seat Dimensional tolerance of bearing seat’s bore
Steel or cast iron
Light alloy or wall thickness less than 6 mm
N6 (N7)
R6 (R7)
A.2.3 The cylindricality of the fit surface of the housing bore shall not exceed
50% of the dimensional tolerance of the housing bore.