GB/T 39655.1-2020Shipbuilding - Ship screw propellers - Manufacturing tolerances - Part 1: Propellers of diameter greater than 2.5 m (English PDF)

Foreword

GB/T 39655 "Tolerances for manufacturing ship propellers for shipbuilding" is divided into two parts:

---Part 1: Propellers with a diameter greater than 2:5m;

---Part 2: Propellers with a diameter of 0:8m to 2:5m:

This part is Part 1 of GB/T 39655:

This section was drafted in accordance with the rules given in GB/T 1:1-2009:

The translation method used in this part is equivalent to the adoption of ISO 484-1:2015 ``Shipbuilding Marine Propeller Manufacturing Tolerance Part 1: Diameter greater than

2:5m propeller:

The Chinese documents that have a consistent correspondence with the international documents cited in this section are as follows:

---GB/T 131-2006 Product Geometric Technical Specification (GPS) Representation of surface structure in technical product documentation

(ISO 1302:2002, IDT):

This part was proposed and managed by the National Ocean Shipping Standardization Technical Committee (SAC/TC12):

Drafting organizations of this section: China State Shipbuilding Industry Research Institute, China Merchants Cruise Research Institute (Shanghai) Co:, Ltd:, Shanghai Overseas

Takahashi Shipbuilding Co:, Ltd:

1 Scope

This part of GB/T 39655 specifies the manufacturing tolerances of marine propellers with a diameter greater than 2:5m:

Note: In some cases, it is allowed to make some adjustments to the deviation based on the judgment of the customer or the designer and the customer:

2 Normative references

The following documents are indispensable for the application of this document: For dated reference documents, only the dated version applies to this article

Pieces: For undated references, the latest version (including all amendments) applies to this document:

ISO 1302 Geometrical Product Specification (GPS) The representation of surface structure in technical product documents [GeometricalProduct

Specifications(GPS)-Indicationofsurfacetextureintechnicalproductdocumentation]

3 Scope of application

This section applies to integral, combined fixed pitch propellers and controllable pitch propellers:

4 Pitch measurement method

4:1 The principle of the measurement method is to measure the length PQ corresponding to the predetermined angle alpha along the spiral of the radius r, and measure the points P and Q

The height difference h relative to the reference surface (see Figure 1):

The length of PQ is measured according to the method of 4:1:1, 4:1:2 or 4:1:3:

Note: When necessary, other methods that meet the accuracy requirements can be used: