Foreword

 

This standard is prepared in accordance with the requirements of GB/T1.1-2019.

Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. The issuer shall not be held responsible for identifying any or all such patent rights.

This standard is proposed and administered by Zhejiang Made Brand Building and Promotion Association.

Zhejiang Fangyuan Testing Group Co. Ltd. takes the lead of organizing the formulation of this standard.

The chief drafting unit of this standard: Zhejiang Yunzhou Technology Co.,Ltd.

The participant drafting unit of this standard:Zhejiang Fangyuan Testing Group Co., LTD., Hangzhou Tengchi Electromechanical Technology Co., LTD., Hangzhou Zhengxu Enterprise Management Consulting Co., LTD. (in no particular order).

The chief drafters of thisstandard: KewangXu,WeiquanLi,ChaoWang, ZhonggengZhao, HailongZhu,  WenboRuan, WanjinHu.

Chief expert for reviewing this standard : Ziying Yu.

This standard shall be interpreted by Zhejiang Fangyuan Testing Group Co. Ltd. 

 

II

Combine harvester stepless gearbox

 

1 Scope

This standard specifies the models and parameters of combine harvester stepless gearbox(hereinafter referred to as gearbox), basic requirements, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage, and quality commitments.

This standard applies to the gearboxes of crawler multifunctional field machines and crawler agricultural conveyors used in conjunction with HST.

2  Normative references

The following documents,in whole or in part,are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) is applicable.

GB/T 1348Spheroidal graphite iron castings

GB/T 2828.1-2012Sampling procedures for inspection by attributes - Part 1: Sampling schemes indexed by acceptance quality limit (AQL) for lot-by-lot inspection

GB/T 3077Alloy structure steels

GB/T 9480Tractors machinery for agriculture and forestry,powered lawn and garden equipment--Operator's manuals--Content and presentation

GB/T 13306Plates

GB/T 13452.2Paints and varnishes--Determination of film thickness

JB/T 9832.2Tractors and machinery for agriculture and forestry -- Paints adherence performance -- Cross-cut test

JB/T 13190  Combine harvester driving axle

3  Models and parameters

3.1  Specification and models

The model of gearbox is composed of enterprise code, HST maximum input power, the sum of maximum output torques at two ends (rounded towards nearest integer), the length of the axle between the two spockets and model code.

 

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Example：XX80(58.8)-20-1200.01 represents the maximum input power of 80 Hp (58.8 kW) ,the maximum

output torques at both ends summed to 20×102 N·m, the drive center distance of 1200 mm and the first approved type of combine harvester stepless gearbox.

3.2  Basic parameters

Basic parameters of gearbox are listed in table 1.

 

Table 1  Basic parameters

Specification and models	HST maximum input power， Hp（kW）	Sum of maximum output torques at both ends	Output speed
XX50-12-XX.XX	50Hp（36.8kW）	12×102N·m	（0～212.8）r/min
XX60-16-XX.XX	60Hp（44.1kW）	16×102N·m	（0～218.5）r/min
XX80-20-XX.XX	80Hp（58.8kW）	20×102N·m	（0～218.5）r/min

 

4  Basic requirements

4.1 Design Requirements

4.1.1The optimized design ability to realize product function, 3D modeling simulation, detachability, the lightening of boxas well asthe ability to analyze the potential failure mode shall be available.

4.1.2 The ability to calculate, analyze and check the strength and fatigue life of gear, drive shaft and bearing shall be available.

4.2 Material Requirements

4.2.1Box material hardness, impact toughness, strength performance shall not be less than the requirements corresponding to QT 450-10 as specified in GB/T 1348.

4.2.2 Hardness, impact toughness and strength of steering gear materials shall not be less than the requirements corresponding to 20CrNiMo as specified in GB/T 3077.

4.3  Processes and equipments

4.3.1 CNC machining center, CNC lathes and other high-precision mechanical equipment shall be available.

4.3.2 Semi-automatic or automatic gearbox assembly line shall be available.

4.3.3 Environment-friendly coating and spraying equipments shall be used for spraying.

4.3.4 Gear tooth profile surface shall be processed by honing or grinding process.

4.3.5 ERP system management of sales, technology, production, procurement, warehouse, quality and finance,etc. shall be available to realize product traceability.

4.4  Testing requirements

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4.4.1 The ability to test gear accuracy, spline accuracy, hardness, box machining accuracy, etc. shall be available.

4.4.2 The ability to test detect air tightness, paint quality, torque, noise, temperature rise, etc. shall be available.

5 Technical Requirements

5.1Appearance quality

5.1.1The exposed surface shall be free from the defects such as bump, rust and deformation of parts.

5.1.2 The metal coating and oxidation treatment layer on the surface of parts shall not flake and/or rust.

5.1.3 The outer surface of exposed fasteners shall be galvanized, passivated or otherwise treated for rust prevention.

5.1.4 Sealing gasket and oil seal lip shall be free from crease, scratch, damage and other defects.

5.2  Assembly requirements

5.2.1 All parts shall be clean and from metal chips, rust and other sundries that affect the cleanliness of the assembly.

5.2.2 There shall be no leakage on the joint surface, gasket and oil seal lip of the gearbox.

5.2.3 The bolts, nuts and other fasteners of the gearbox shall comply with the relevant requirements for the metric bolt tightening force and shall not be loose and there shall be no absence of parts.

5.2.4 All moving parts of the gearbox should move flexibly, without stuck, tandem movement, impact and abnormal sound.

5.2.5 The shift of the gear of the gearbox shall be light, smooth, flexible, accurate, reliable, easy,no stuck and/or jump.

5.2.6 When steering rocker armoperated,the corresponding drive shaft shall stop rotating and resume normal rotation after the control.

5.3Joint mounting dimensions

Mounting holes of steering cylinder,HST, input shaft support , steering arm and gearbox assembly , auxiliary transmission handle mounting dimensions, the length of the axle between the two spockets,hoop mounting dimensions, drive shaft and drive wheel matching dimensions and other external connection dimensions shall meet the drawing design requirements.

5.4  Paint film quality

5.4.1 The thickness of the paint film shall not be less than 50μm.

5.4.2 Coating adhesion shall not be above Grade Ⅱ.

5.5  Performance requirements

5.5.1  Air tightness test

The test of the gearbox shall be carried out under the test pressure ranging from 0.25MPa to 0.30MPa, and the pressure shall be kept for 3 min. There shall be no bubbles in each part during the test.

5.5.2  Maximum torque

The tested maximum torque value Shall meet the requirements for maximum torque design value of the gearbox.

5.5.3  Maximum steering rocker arm change angle

The requirements for the maximum steering rocker arm change angle prescribed in the product drawings or technical documents shall be met. Steering rocker arm shall rotate freely within the required range of the maximum steering change angle without interference phenomenon, and the deviation of the maximum steering change angle shall not be greater than 1°.

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5.5.4  Cleanliness

The cleanliness limit of the gearbox shall be measured by the volume of the calibrated perfusion volume of the working medium. The cleanliness value shall not be greater than 50 mg/L, and the maximum diameter of a single solid particle in the box shall not be greater than 80 μm.

5.5.5  Noise

The noise of gearbox under no-load shall not exceed 88 dB (A).

5.5.6  Oil Temperature

When the ambient temperature is kept at 10℃~ 35℃, under no load, the gearbox runs continuously for 2 h at the highest speed. And when the oil temperature remains stable, the highest oil temperature shall not exceed 90℃, and the temperature rise not exceed 65 K.

5.6  Transmission efficiency

The transmission efficiency of the gearbox shall not be less than 88 %.

5.7  Durability

The gearbox shall be able to pass the 800 h durability test, and after the test all parts can still work normally without any damage.

5.8  Reliability

The mean failure time of gearbox shall not be less than 400 h, and the effectiveness shall not be less than 97%.

6  Test methods

6.1  Appearance quality

Conduct visual inspection.

6.2  Assembly requirements

6.2.1 Under no-load operation,by controlling the shifting forks , easily shift, free shift, no stuck and jump phenomenon shall be realized.

6.2.2In case of operating the left or right steering arm under no-load , the corresponding drive shaft shall stop rotating, and the drive shaft shall resume normal rotation after the end of steering operation.

6.2.3Other items shall be inspected visually or manually.

6.3  Joint mounting dimensions

Calipers, normal micrometers or special gauges shall be used to measure the joint mounting dimensions.

6.4  Paint film quality

6.4.1Paint thickness shall be tested according to the method specified in GB/T 13452.2.

6.4.2Coating adhesion shall be tested according to the method specified in JB/T 9832.2.

6.5  Performance requirements

6.5.1  Air tightness test

According to Appendix A to JB/T 13190 -- 2017, the test pressure ranges from 0.25MPa to 0.30MPa.

6.5.2  Maximum torque

The test shall be carried out according to Appendix Ato this document.

6.5.3  Maximum steering rocker arm change angle

Operate the left and right steering rocker arms of the gearbox and measure the maximum steering change angle of the steering rocker armfrom the moment the steering arm is subjected to force until the friction plate is compacted.

6.5.4  Cleanliness

The test shall carry out according to Appendix C to JB/T 13190—2017.

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6.5.5  Noise

The test shall carry out according to Appendix D to JB/T 13190—2017.

6.5.6  Oil Temperature

The test shall carry out according to Appendix E to JB/T 13190—2017.

6.6  Transmission efficiency

The test shall carry out according to Appendix G to JB/T 13190—2017.

6.7  Durability

The test shall carry out according to Appendix B to JB/T 13190—2017.

 

6.8  Reliability

The test shall carry out according to Appendix F to JB/T 13190—2017.

7  Inspection rules

7.1 Inspection classification

Inspection falls into delivery inspection and type inspection.

7.2  Delivery inspection

7.2.1The gearbox shall be tested qualified by the quality assurance department and attached with the certificate before leaving the factory.

7.2.2 The delivery inspection items are listed in table 2.

7.3  Type inspection

7.3.1 In case of any of the following circumstances, the type inspection shall be carried out:

a) trial production of new products,the products transferred to another factory for production or type approval of new products;

b) during the normal production, significantchanges of product structure, materials, technology and processing methods of key processes which may affect the product quality;

c) a big difference between the results of the delivery inspection and that of the previous type inspection;

d) production resumes after the productiondiscontinued for more than one year;

e) at least once two years for normal production;

f) upon the request of the national quality supervision agency for type inspection.

7.3.2Sample three gearboxes for type inspection.Type inspection items are listed in table 2.

 

5 Table 2Inspection items

 

Items	Requiremens	Test methods	Delivery inspection		Type inspection
			Full inspection items	Random inspection items
Appearance quality	5.1	6.1	√	—	√（samples 1#～3#）
Assemblyrequirements	5.2	6.2	√	—	√（sample 1#）
Joint mounting dimensions	5.3	6.3	—	√	√（sample 1#）
Paint film quality	5.4	6.4	—	—	√（sample 1#）
Air tightness test	5.5.1	6.5.1	√	—	√（sample 1#）
Maximum torque	5.5.2	6.5.2	—	—	√（sample 1#）
Maximum Steering rocker arm change angle	5.5.3	6.5.3	—	—	√（sample 1#）
Cleanliness	5.5.4	6.5.4	—	—	√（sample 2#）
Noise	5.5.5	6.5.5	—	—	√（sample 1#）
Oil temperature	5.5.6	6.5.6	—	—	√（sample 1#）
Transmission efficiency	5.6	6.6	—	—	√（sample 1#）
Durability	5.7	6.7	—	—	√（sample 1#）
Reliability	5.8	6.8	—	—	√（sample 3#）

 

7.4 Judgment rules

7.4.1  Delivery inspection

For testing the Joint mounting dimensions, sample the products according to GB/T 2828.1 - 2012 with IL and AQL set as S-1 and 2.5 respectively. If the number of unqualified pieces exceeds thatprescribed by AQL 2.5, the whole batch shall be judged as unqualified. For the full inspection items, if there is one unqualified item, the whole batch shall be judged as unqualified.

7.4.2  Type inspection

For type inspection，if there is one unqualified item, the products shall be judged as unqualified.

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8 Marking, packaging, transportation and storage

8.1  Marking

8.1.1The product labelcomplying with the requirements specified in GB/T 13306 shall be fixed in a prominent position of the gearbox and shall contain the following contents:

a) product model and name;

b) name, address of the manufacturerand trademark ;

c) production date and product number;

d) identification required by the demander;

e) implementation standard code of the product.

8.1.2 The packing case label (if the packing case is used) shall contain at least the following contents:

a) product name and code (including demander's special requirements for product label);

b) quantity of products in the package and total quality;

c) external dimensions of the packing case;

d) production date;

e) name, address of the manufacturerand trademark ;

f) "Handle with Care", "Keep away from moisture", "upward", etc.

8.2  Packaging

8.2.1 The packaging of the CVT shall meet the requirements of the demander and be dustproof and waterproof.

8.2.2  For the unpackaged gearbox fixed with special bracket, the following parts shall be protected:

a) exposed spline;

b) exposed oil outlet;

c) exposed joint surface.

8.2.3 The documents attached to the package of the the gearbox shall include the product quality certificate, instruction manual and list of the documents. The instruction manual shall be prepared in accordance with the provisions of GB/T 9480.

8.3  Transportation

In transportation, safety protection measures shall be used to prevent the gearboxes from knock and damage .

8.4  Storage

The gearboxes shall be stored in ventilated, dry, rain proof and sunscreen places. It shall not be stored with flammable products, chemical corrosion products and other harmful goods. The placement of the gearboxes shall ensure that they will not be deformed and knocked.

9Quality commitments

9.1 Within two years or 800 hours from the date of sale ,whichever comes first prevails, the whole machine (except the wearing parts), under normal use, if quality problem occurs, the manufacturer shall provide corresponding parts for replacement. If the product cannot be used normally due to improper control of the user or other non-product quality problems, the product manufacturer can assist the customer to deal with it upon the request of the customer.

9.2 Vulnerable parts (including oil seal, O-ring, gasket, friction plate and bimetal bushing) within one year or 500 hours from the date of sale of the whole product whichever comes first prevails. Under normal use, if quality problems occur, the manufacturer shall provide corresponding parts for replacement . If the product cannot be used normally due to the user’s improper operation of the gearbox or other non-product quality

 

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problems, the product manufacturer can assist the customer to deal with it upon the request of the customer.

9.3 The manufacturer shall provide technical consultation and support to customers timely through telephone, wechat, call center and other channels as required by customers. When users have objections to the quality of products, the manufacturer shall deal with them and make a respondence within 24 hours to provide services and solutions for customers.

 

8.

Annex A

(informative)

Test method for maximum torque

 

A.1  Selection of Prime mover

 

Select the prime mover according to the rated power of HST with matching displacement.

 

A.2 Connection Modes

The prime moverdrives the HST bythe belt (to ensure the rated inputspeed of the HST ).HST drives the gearboxby the input gear, which is fixed on the test bench by the hoops, and the drive axles on both sides of the gearboxare connected with the torque loader.

 

A.3  Trial run of test equipments

Adjust the gear of the gearbox is to neutral and set the torque loader underno load, start the prime mover and drives the gearbox by HST. The gear of the gearbox is shifted from low to high one by one, and the stepless speed regulation of the gearbox is realized by adjusting the HST. The gearbox runs normally in each gear for 10 minutes prior to the follow-up tests. In normal condition, subject the torque loader to 30% of the maximum allowable torque designed for the gearbox and then increase the load of torque on both ends of the drive axle of the gearbox synchronously and observe whether the gearboxruns normally.

 

A.4 Test Procedures

Adjust the torque loaders gradually to increase the load of torque on the gearbox synchronously with an increase of 10 % of the maximum torque designed for the gearbox each time.When the load of torque reaches 70% of the maximum output torque designed for the gearbox, gradually increase the load of torque by 5% of the maximum torque designed for the gearbox each time until it reaches the maximum output torque designed for the gearbox and the gearbox runs normally.