GOV MEC_WSM_0001158_01

03:01-03 Issue 1

Mechanical governor Function and work description Industrial & Marine Engines

Part No. 1 588 661

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Scania CV AB, Sweden, 1999-02:01

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General - The governor governor is intended intended to maintain maintain an engine speed speed that corresponds corresponds to the throttle position. - If a governor governor is not used, used, engine engine speed will decrease decrease until until the engine engine stops or increase to surging speed. - Industrial Industrial and marine marine engines may be be equipped with with six different different types of injection pump governor depending on operational conditions. The types include 4 all speed governors and 3 single speed governors. The governor type is indicated by a code in the complete engine designation as shown by the following examples.

DSI14 50 M21SLR where where S indicates the governor type.

Table of contents c ontents Governor types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 All speed governors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Single speed governor (generator set) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 All speed governors, general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 RQV governor (Q) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 RQV-K governor (K) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 RSV governor (S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 RQ governor (T) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 GAC (electronic governor) (D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 RSV governor (S) for single speed operation. . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Function, RQV governor governor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Function, RQV-K governor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Function, RSV governor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Function, RQ governor. governor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Work Description Testing and overhaul of injection pumps and governors . . . . . . . . . . . . . . . . 27 Idle speed inspection, RQV, RQV-E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Idle speed inspection, RSV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Adjustment of speed drop, RSV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Engine speed inspection, RQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Parallel operation - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Replacement of rubber dampers in governor hub RQV, RQV-K, RQ . . . . . 35

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General - The governor governor is intended intended to maintain maintain an engine speed speed that corresponds corresponds to the throttle position. - If a governor governor is not used, used, engine engine speed will decrease decrease until until the engine engine stops or increase to surging speed. - Industrial Industrial and marine marine engines may be be equipped with with six different different types of injection pump governor depending on operational conditions. The types include 4 all speed governors and 3 single speed governors. The governor type is indicated by a code in the complete engine designation as shown by the following examples.

DSI14 50 M21SLR where where S indicates the governor type.

Table of contents c ontents Governor types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 All speed governors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Single speed governor (generator set) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 All speed governors, general . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 RQV governor (Q) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 RQV-K governor (K) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 RSV governor (S) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 RQ governor (T) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 GAC (electronic governor) (D) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 RSV governor (S) for single speed operation. . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Function, RQV governor governor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Function, RQV-K governor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Function, RSV governor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Function, RQ governor. governor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Work Description Testing and overhaul of injection pumps and governors . . . . . . . . . . . . . . . . 27 Idle speed inspection, RQV, RQV-E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Idle speed inspection, RSV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Adjustment of speed drop, RSV . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Engine speed inspection, RQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Parallel operation - adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Replacement of rubber dampers in governor hub RQV, RQV-K, RQ . . . . . 35

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Governor types

All speed governors The following all speed governors are available:

Code

Bosch design.

Description

S

RSV

All speed governor for e.g. ship propeller engines and some types of hydrostatic drives.

Q

RQV

All speed governor for e.g. motor vehicles or similar applications as operated by an accelerator pedal.

K RQV-K

All speed governor for high performance marine engines.

On the governor housing there is a type plate indicating - gover governo norr type type - intended intended injectio injection n pump pump speed range (i. e. half the engine speed) - Bosch Bosch govern governor or design designatio ation n

BOSCH made in Germany

RSV350-1100 P8A 664

e.g. all speed governor type RSV, intended for engine speed 700 - 2200 rpm

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Single speed governor (generator set) The following single speed governors are available:

Code

Bosch design.

Description

T

RQ

mechanical single speed governor for generator set

D

GAC+ RQ

combination electronic, GAC, and mechanical (RQ or RSV) Governor for generator sets where accurate control is required

S

RSV

Mechanical all speed governor that can also be used as single speed governor.

On the governor housing there is a type plate indicating - governor type - intended injection pump speed range (i. e. half the engine speed) - Bosch governor designation

BOSCH made in Germany

RQ750 PA 1299

e.g. single speed governor type RQ, intended for engine speed 1500 rpm

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All speed governors, general The main difference between all speed governors is their speed drop properties.

Nominal output (%)

Speed drop is a term describing the change in engine speed which occurs when load is applied or removed and throttle position remains unchanged. This might also be referred to as (percentage) engine speed change. Mathematically, this may be expressed as:

Speed drop

High idle speed %=

Nominal engine speed

Nominal engine speed

Example:

2070

x 100

1800

15 % =

x 100 1800

The speed drop can also be calculated for partia lly open throttle. The speed drop in percent increases as engine speed decreases. The speed drop may be illustrated according to Fig. 1.

Available output

Fig. 1. Speed drop at 100% nominal output

In order to simplify the comparison we let the engine output be represented by a straight line (vertical) which designates 100 % available out put at all different engine speeds. This line will then also represent the maximum control rack travel. See Fig. 2.

100% output at the engine speed concerned (max. control rack travel) Nominal output curve

Speed drop curves

Fig. 2. Speed drop curves for 100% available output at different engine speeds 03:01-03

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RQV governor (Q) The RQV governor is used in some industrial engines. It has a characteristic that provides a speed drop of 10 - 15 % at full output rpm. This governor is suitable for most types of motor vehicles or similar applications where low speed drop at medium speed is not specifically required. This governor is used in trucks, dumpers, forklift trucks etc. where engine speed is controlled using an accelerator pedal. The RQV governor provides a relatively large speed drop at low engine speeds. The RQV governor is not very suitable for applications requiring high output at low engine speed.

Available output

Fig. 3. Example of speed drop curves for RQV governors at different engine speeds

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RQV-K governor (K) The RQV-K governor is used in some high output marine engines. The RQV-K governor is a special configuration of the RQV governor. The difference is that the RQV-K governor makes it possible to control the engine torque curve in order to provide optimum operational characteristics. Thus, the RQV-K governor is used in some high output marine engines where not too high output is required at low engine speed (risk of engine damage).

Available output

Fig. 4. Example of speed drop curves for RQV-K governors at different engine speeds

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RSV governor (S) The RSV governor is used as standard governor in many industrial and marine engines, all speed as well as single speed. The RSV governor is characterised by a relatively constant slope of the speed drop curves across the entire speed range. The speed drop is adjustable between 4.5 and 11 % at full output engine speed. The RSV governor is often suitable in applications where low or parallel speed drop is required mainly at low engine speed. These properties means that it may also in some cases be used as a single speed governor in engines intended for generator sets. - The RSV governor reacts more slowly on changes in load than the RQ governor. - The RSV governor requires higher throttle operation force than the RQV and RQV-K governors

Available output

Fig. 5. Example of speed drop curves for RSV governors at different engine speeds

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RQ governor (T) The RQ governor is used in industrial as well as marine engines for generator sets. The characteristic of this governor only permits that the engine operates at a preset speed: 1500 or 1800 rpm. In order to change the engine operating speed, the governor springs must be replaced. The governor speed drop is low, 4 - 5 %. It also reacts quickly on changes in load. In order to obtain a straighter speed drop curve, thus improving parallel operation properties, the injection pump is equipped with pressure valves without idle holes.

Fig. 6. 0-hole pressure valve

Available output

Fig. 7. Example of speed drop curves for RQ single speed governors at different engine speeds

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RSV governor (S) for single speed operation Engines with RS3000 series injection pumps, as used in single speed operation, are fitted with RSV governors set to single speed configuration. The speed drop is then adjusted to 4 - 5 % at nominal full output engine speed; 1500 or 1800 rpm. In order to obtain a more linear speed drop curve, thus improving parallel operation properties, the injection pump is equipped with pressure valves without idle holes.

Available output

Fig. 8. Example of speed drop curves for RSV all speed governor, set to single speed configuration, at different engine speeds

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GAC (electronic governor) (D) The GAC governor is optionally fitted to engines intended for generator sets.

The GAC governor enables stepless control of speed drop between 0 and 5%.

The GAC governor is available in combination with the RQ as well as the RSV governor.

This governor combination is used where speed drop and parallel operation properties are subject to special requirements and in applications with automatic functions for load distribution and synchronisation.

The actual speed control is executed by the electronic governor, the mechanical governor acting as overreving protection. The mechanical governor is set to an engine speed above the nominal operating speed. For example, when operating speed is 1500 rpm the mechanical governor would be set to 1800 rpm.

This governor combination is also suitable in installations where the input rotating mass is small. The GAC governor is described in a separate section.

Available output

Fig. 9. Example of speed drop curves for GAC + RQ or RSV governors at different engine speeds Speed drop is adjustable between 0 and 5%

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Function, RQV governor

6

7

8 9

16 15 14

1 5 2 3 4

12 1. 2. 3. 4. 5. 6. 7. 8.

10 11 13

Control lever Linkage lever Guide bolt Cam plate Fulcrum lever Link Spring seat Clearance compensation spring

9. 10. 11. 12. 13. 14. 15. 16.

Control rack Pressure ring Guide screw Sprung sliding bolt Angular lever Flyweight Governor springs Setting nut

Fig. 10. RQV governor

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General The governor hub is driven by the injection pump camshaft by way of a damper. The governor springs (15) are fitted in the flyweights (14). The weights move out when engine speed increases within the prescribed control range. The angular levers (13) for the flyweights are suspended in the governor hub. Each control lever position corresponds to a specific engine speed where speed drop starts. The control lever (1) movement is transmitted to the control rack (9) by way of the two-section linkage lever (2) (elbow joint) and the guide bolt (3) in the fulcrum lever (5). The fulcrum lever pivot point can be moved in the linkage guide. In addition, it is guided by a plate cam (4), fitted in the governor cover, so that the fulcrum lever transfer ratio changes.

1. 2. 3. 4.

Inner spring seat Flyweight Outer spring seat Setting nut

The sliding bolt (12) is sprung in both directions. If the engine is subjected to heavy load and engine speed decreases, the control rack is pressed against the full load stop. The sprung sliding bolt is compressed by the flyweights, which are forced inwards by the governor springs. If the engine speed rises, the control rack is pressed towards the stop position, the sliding bolt spring being extended by the flyweights, which are pressed outwards by the centrifugal force. Normally, 3 governor springs interact in each flyweight. Shims may be used. The outer spring influences the governor properties at low engine speed and the two inner springs influence the properties at high engine speed. The engine is stopped by pulling the stop lever towards the stop position. The control rack is then forced back into zero feed position and fuel feed to the nozzles stops.

5. Full speed springs 6. Idle speed springs A = idle speed travel B = full speed travel

Fig. 11. Operation of governor springs 03:01-03

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Principles of operation Engine stopped, RQV Control rack is in stop position and flyweights are in their inner positions.

Cranking position, RQV Control lever moves towards full speed stop. Control rack moves towards stop in order to supply as much fuel as possible to engine when it starts.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

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Control lever Linkage lever Guide bolt Plate cam Fulcrum lever Link Spring seat Clearance compensation spring Control rack Pressure ring Guide screw Sliding bolt with protective spring Angular lever Flyweight

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15. 16. 17. 18. 19. 20. 21. 22. 23.

Governor springs Setting nut Full speed stop Idle speed stop Injection pump camshaft Governor hub Cranking quantity stop Pump plunger Stop lever

A = Control rack stop position B = Control rack max. position C = Control rack cold start position


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Idle speed position, RQV When engine has started and control lever has been released, control lever returns to idle speed position, i.e. moves toward low speed stop. Control rack also moves into idle speed position as determined by governor. The fuel quantity supplied to the engine is now sufficient for maintaining an even idle speed.

Medium speed position, RQV If load is applied to or removed from the engine at the engine speed corresponding to the throttle position, the governor will maintain the set engine speed along the speed drop curve by increasing or decreasing the fuel quantity.

Full speed position, RQV When the engine reaches the maximum full output engine speed, full speed control starts. The flyweights move out towards their outermost positions, acting on the control rack, moving it towards stop. If the engine load is completely removed, the high idle speed will be achieved.

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Function, RQV-K governor

1. 2. 3. 4. 5. 6. 7.

Rocker arm Link Fulcrum lever Guide arm Sliding bolt Angular lever Cam plate

8. 9. 10. 11. 12. 13. 14.

Control rack Setting nut Outer spring seat Governor spring Flyweight Inner spring seat Full load stop with curve path

Fig. 12. RQV-K governor

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Principles of operation Engine stopped, RQV-K Control lever rests against stop and control rack is in stop position. Flyweights are in their inner position.

Cranking position Control lever moves towards full speed stop. Rocker arm moves below full load stop in order to supply as much fuel as possible to engine when it starts. Control rack moves against start quantity stop.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

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Control lever Linkage lever Guide bolt Cam plate Fulcrum lever Link Rocker arm Cam plate return spring Control rack Pressure ring Guide arm

12. 13. 14. 15. 16. 17. 18. 19. 20.

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Sliding bolt Angular lever Flyweight Governor springs Setting nut Injection pump camshaft Cranking quantity stop Pump plunger Full load stop with curve path (adjustable)


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Idle speed position (RQV-K) When engine has started and control lever has been released, control lever returns to idle speed position, i.e. moves toward low speed stop. The resilient rocker arm then slides below full load stop, returning into idle speed position, and control rack is brought into idle speed position. The fuel quantity supplied to the engine is now sufficient for maintaining an even idle speed. Full load quantity at low and medium engine speed When control lever is brought from idle speed position towards full load quantity, guide bolt (3) moves along curve path of plate cam (4) and, at the same time, downwards in fulcrum lever guide. Then, fulcrum lever pivots around pivot point on pressure ring (10), pushing control rack towards full load quantity. Engine speed increases and governor flyweights move outwards, bringing sliding bolt somewhat to the right. This causes a rotary motion, raising guide arm and fulcrum lever so that rocker arm (7) slides along curve path of full load stop. When guide bolt slides down into fulcrum lever guide path, cam plate is brought from its stop after overcoming return spring force. If engine speed increases further, the governor flyweights will move further outwards and the rocker arm will slide along the full load stop curve path, increasing the full load quantity (negative torque control). After the turning point, equalisation takes place by reducing the full load quantity (positive torque control). When torque control ends, the plate cam returns, resting against the stop in housing, and breakaway starts. If load is applied to or removed from the engine at the engine speed corresponding to the throttle position, the governor will maintain the set engine speed along the speed drop curve by increasing or decreasing the fuel quantity.

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Full speed position When the engine reaches the maximum full output engine speed, full speed control starts. The flyweights move out towards their outermost positions, acting on the control rack, moving it towards stop. If the engine load is completely removed, the high idle speed will be achieved.

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Function, RSV governor

1 15 4

16

5 8 9

14 13

7

3 2

6

11 1. 2. 3. 4. 5. 6. 7. 8.

Control lever Pivot lever Rocker arm Governor spring Tension arm Torque control spring Auxiliary idle spring Idle speed stop

10 9. 10. 11. 12. 13. 14. 15. 16.

12 Guide arm Sliding bolt Flyweight Fulcrum lever Link Control rack Start spring Smoke limiter housing

Fig. 13. RSV governor

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The RSV governor is fitted with a pivoting governor spring (4) and two linked flyweights (11). The desired engine speed is set with the fulcrum lever (1), which, by way of the pivot lever (2), is directly linked to the governor spring, which in turn is linked to the tension lever (5). When the set engine speed is reached, there will be an equilibrium between the forces of the governor spring and the flyweights acting on the tension lever. The control rack (17) is influenced by the fulcrum lever (15), which in turn is controlled by the flyweights by way of a linkage system. The start spring (8), attached to the upper part of the fulcrum lever, pulls the control rack against the full load stop when the engine is not running. The governor speed drop can be changed by the governor spring setting screw (22). A separate auxiliary idle spring (7) stabilises the governor at low idle speed. The illustrations in the following pages show the principles of these components and their operation in different operational states. The torque control spring (6) normally has no function in governors used in Scania engines.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22.

Control lever Pivot lever Rocker arm Governor spring Tension arm Torque control spring Auxiliary idle spring Start spring Guide arm Sliding bolt Flyweight Angular lever Governor hub Injection pump camshaft Fulcrum lever Link Control rack Idle speed stop Full speed stop Pump plunger Full load stop Setting screw


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Principles of operation Engine stopped, (cranking position), RSV The control rack always is in full load position, regardless of the control lever position, when the engine is not running. The illustration shows cranking position with cold start switched on. The full load stop has been moved and allows the control rack to reach the cold start position.

Idle speed position, RSV The control lever rests against the idle speed stop. Thus, there is practically no tension on the governor spring, which is almost in a vertical position. The spring pull is low and the flyweights move out also at low speed. As a result, the sliding bolt moves in the direction indicated by the arrow and the guide arm follows. The guide arm pivots the fulcrum lever so that the control rack is brought towards stop into idle speed position. The tension lever moves against the auxiliary idle spring, which supports the idle speed control.

Medium speed position, RSV A slight movement of the control lever from the idle speed position is sufficient for the control rack to move from its initial position into full load position. The injection pump delivers full load quantity to the engine and engine speed increases. As soon as the centrifugal force is higher than the spring tension corresponding to the control lever position, the flyweights move out. Then, the sliding bolt, by way of the fulcrum lever, brings the control rack back to a smaller fuel quantity. The engine speed does not increase more but is maintained at a constant level by the governor.

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Full speed position, RSV When the control lever rests against the full load stop, the governor operates in the same way as described under "Medium speed position", the difference being that the pivot lever fully tensions the fulcrum lever. The governor spring thus pulls the tension lever against the full load stop and the control rack towards full load with higher force. When the engine load is fully removed, the high idle speed is reached.

Stop position, RSV The control rack is brought into stop position when the stop lever is moved to the stop position. When the stop lever is moved to stop, the fulcrum lever upper part pivots around pivot point C in guide arm to the right. The link thereby pulls the control rack into stop position. A return spring (not shown) returns the stop lever into its initial position when it is released.

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Function, RQ governor

5

7

6

8

16

15 14 13

1 4 3 2

9

1. 2. 3. 4. 5. 6. 7. 8.

10

Control lever Linkage lever Guide bolt Fulcrum lever Link Spring seat Clearance compensation spring Control rack

11

12

9. 10. 11. 12. 13. 14. 15. 16.

Pressure ring Guide screw Sliding bolt Angular lever Flyweight Governor springs Setting nut Smoke limiter

Fig. 14. RQ governor

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The illustrations show the principles of the main components and their operation. The design and operating principles of the RQ governor are similar to those of the RQV governor. The difference is that the RQ governor has no plate cam and that the fulcrum lever transfer ratio is different. In addition, different governor spring combinations are fitted. 2 or 3 governor springs interact in each flyweight. The control lever is normally fixed at nominal full output engine speed. In parallel operation, the control lever is adjustable.

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

Control lever Linkage lever Guide bolt Fulcrum lever Link Spring seat Clearance compensation spring Control rack Pressure ring Guide screw Sprung sliding bolt Angular lever Flyweight

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14. 15. 16. 17. 18. 19. 20. 21. 22.

Governor springs Setting nut High speed stop Low speed stop Pump plunger Governor hub Injection pump camshaft Full load stop Stop lever



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Engine stopped and cranking position, RQ The control lever is always in operating position. Control rack is in its max. position in order to sup ply as much fuel as possible to engine when it starts.

Full speed position, RQ When the engine reaches its maximum permissi ble full output speed, the flyweights overcome the force of the spring assembly full speed springs and breakaway starts. When this occurs, the angular levers, by way of the governor hub and the pressure rings, act on the fulcrum lever, bringing the control rack from max. towards stop.

Single speed governor RSV Single speed governor RSV operates according to the same principles as all speed governor RSV. The difference is, however, that single speed governor RSV never operates at idle speed or medium speed.

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Work Description

Testing and overhaul of injection pumps and governors Overhaul and testing must only be performed by workshops with skilled personnel and the necessary equipment. For repair instructions for pump and governor, refer to the pump manufacturer or their representative. Pump and governor must be adjusted according to Scania's test tables. The test tables state the setting values and test equipment required for a specific pump type. The test tables are included in Workshop Manual "Injection Systems".

Idle speed inspection, RQV, RQV-E 1. Run engine until it reaches normal operating temperature. Check that control lever rests against low speed stop when accelerator pedal is released and is pressed against full speed stop when accelerator pedal is depressed. Adjust as required.

Fig. 15. Inspection of throttle control

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2. Use a separate tachometer as shown. The tachometer of the installation is not accurate enough.

Fig. 16. Engine speed measurement

3. Run engine at low idle speed and check engine speed. Adjust by screwing low speed stop out or in. Run engine without load at maximum speed, i.e. high idle speed. Adjust by screwing full speed stop out or in. Low idle speed

For industrial engines:

500 rpm.

For marine engines:

700 rpm.

(other idle speeds may occur) High idle speed

For industrial and marine engines: Refer to engine card. Seal full speed stop with a guarantee seal.

1. Low speed stop 2. Full speed stop Fig. 17. 11 and 12 engine with RQV or RQV-K governor

Fig. 18. 9 and 12 engine with RQV or RQV-K governor 28

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Idle speed inspection, RSV 1. Run engine until it reaches normal operating temperature. Check that control lever rests against low speed stop when accelerator pedal is released and is pressed against full speed stop when accelerator pedal is depressed. Adjust as required.

Fig. 19. Inspection of throttle control

2. Use a separate tachometer as shown. The tachometer of the installation is not accurate enough. 3. Run engine at low idle speed and check engine speed. Adjust by screwing low speed stop out or in. Run engine without load at maximum speed, i.e. high idle speed. Adjust by screwing full speed stop out or in. Low idle speed

For industrial and marine engines:

700 rpm.

Fig. 20. Engine speed measurement

(other idle speeds may occur) High idle speed

For industrial and marine engines: Refer to engine card. Seal full speed stop with a guarantee seal. When adjusting the low idle speed, the auxiliary idle speed screw must be screwed out so far that the engine just runs evenly. If the engine does not run evenly after adjustment of low idle speed, the auxiliary idle screw can be set so that engine just runs evenly. Adjustment of low idle speed must not be performed using the auxiliary idle screw. When the engine is used in a generator set, the auxiliary idle screw should be screwed out completely. When adjusting the high idle speed, the auxiliary idle screw must be completely screwed out.

1. Full speed stop 2. Low speed stop 3. Auxiliary idle screw Fig. 21. RSV governor

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Adjustment of speed drop, RSV - The speed drop is adjustable between 4 and 11% at full output engine speed. Adjustment is by increasing or decreasing governor spring tensioning. This is done with a setting screw with "click" locations for each quarter of a turn. - The governor spring is pretensioned to a suitable "x value" stated in the test table. - The x value setting screw is accessible from above using a screw or a hexagon driver. See illustration. The idle speed screw and the auxiliary idle spring must be screwed out completely. - Fully screwed in setting screw corresponds to x=0. x=1 means that setting screw is screwed out (counter-clockwise) 1 turn=4 clicks. Normally, the setting screw must not be screwed out more than x=6 i.e. 24 clicks or 6 full turns. - Example: x = 2.25 means that the setting screw is screwed out 2 1/4 turns. - An increase in the x value means an increase in speed drop. The table value of x is an approximate value intended for quickly achieving the correct speed drop setting.

1. Control lever in stop position 2. Idle speed screw 3. Auxiliary idle spring Fig. 22. Adjustment of speed drop, RSV all speed governor

- After the speed drop has been set, high and low idle speed and the auxiliary idle spring must be adjusted.

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Engine speed inspection, RQ The RQ governor is only intended to operate within a narrow speed range between full output speed and high idle speed (0 - load speed). Operation at a speed lower than the nominal speed (with some allowance) is not possible.

Inspection of high idle speed Use the installation frequency meter or a separate tachometer as shown. 50 HZ = 1500 rpm (direct flanged generator) 60 HZ = 1800 rpm (direct flanged generator) Adjusting fixed speed:

Run engine without load. Adjust engine speed by screwing full speed stop out or in.

Fig. 23. Adjustment of engine speed, RQ governor

Adjustment range: 1465 - 1610 for RQ750 governor 1755 - 1935 for RQ900 governor Engines equipped with electric speed setting motor do not have a full speed stop. Normally, engines will be adjusted to the following speed: 100 % load

0 load

50 Hz = 1500 rpm 52.5 Hz = 1575 rpm (direct flanged generator) 60 Hz = 1800 rpm Note!

63 Hz = 1890 rpm

The permissible operating range of the control lever is between 20o and 40o. At too wide an angle there is a risk of control rack hunting. At too small an angle the engine will stop.

The control lever angle can be determined by measuring the distance between the control lever and the mating face between governor cover and governor housing, refer to illustration and table.

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Control lever length

Dimension A, mm At 0°

At 20°

At 30°

At 40°

40

69

56

42

55

75

57

Control lever parallel with mating face


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Adjustment of speed drop The speed drop is adjustable within a narrow range between approx. 4.5 % and 5.5 %. Adjustment is by increasing or decreasing governor spring tensioning. This is done with a setting nut with "click" locations for each quarter of a turn. There is one nut for each spring assembly. The setting nut is accessible by removing a plug to one side of the governor housing. - When the nut is screwed in, speed drop increases. To maintain full output speed, control lever angle must be reduced. - When the nut is screwed out, speed drop decreases. To maintain full output speed, control lever angle must be increased. - Maximum permissible tensioning is 3.5 turns.

1. Setting nut

- Minimum permissible tensioning is 0 turns. The initial position (0 turns) is when upper fa ce of nut is flush with screw outer end face.

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Fig. 24. Initial position when adjusting speed drop


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Parallel operation - adjustment Parallel operation is possible with variable speed as well as single speed engines. First, check that the engines and the injection pumps are of the same type and that they have been adjusted and run as equally as possible.

Variable speed engines

Single speed engines

- Adjust the high and low idle speeds on all engines individually until the values are as equal as possible.

- synchronise the engines and run them at 75 % load. Adjust throttle operation so that load is equally distributed among engines.

- Ensure that the throttle operation of the engines is fully parallel.

- Run engines at 100 %, 75 %, 50 %, 25 %, and 0 % load and read out the load electrically using integral or separate kW meter (or ammeter).

- If the engines have individual drive shafts: check speed at common throttle operation at 25 %, 50 %, 75 %, and 100 % WOT. - If the engines have a common shaft: compare exhaust temperatures at 25 %, 50 %, 75 %, and 100 % WOT (load). An exhaust temperature variation of ± 25° C between individual engines is normally permissible.

- If load distribution is uneven, the speed drop curve slope can be adjusted as described above. Examples are shown overleaf.

- Adjust throttle operation parallelism and transfer ratio as necessary.

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Example: - Engine B yields 100 % output at 50.4 Hz.

Load

- Engine A then only yields 75 %. Thus, the speed drop must be increased for engine B or reduced for engine A. The maximum permissible deviation in load distribution according to ISO 3046 is 10 % in the load range 20 - 100 %. It is calculated according to the formula: Read-out output/engine

Read-out total output

Max. engine output/engine

Max. total output

x 100 = .... %

In the above example, a calculation of the deviation in load distribution gives the following result: - Maximum engine output/engine = 300 kW - Read-out output for engine A = 225 kW

Fig. 25. Example of load distribution in a two engine installation

- Read-out output for engine B = 300 kW - Read-out total output = 525 kW

Output, kW

- Maximum total output = 600 kW resulting in: Engine A 225

525 x 100 = -12.5 %

300

600

Engine B 300

525 x 100 = -12.5 %

300

600

i. e. the deviation in load distribution exceeds the permissible 10 % and the speed drop for one of the engines must be adjusted.

Fig. 26. Example of calculating load distribution in two engine installation

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Replacement of rubber dampers in governor hub RQV, RQV-K, RQ 5

7

6

8

16

15 14 13

1 4 3 2

10

9

- Measure high and low idle speed. - Remove control and stop lever. - Remove guide screw (10). - Remove governor cover. - Detach fulcrum lever (4) from link (5). Bend fulcrum lever 90° to the rear and remove it along with pressure ring (9). - Remove screw from governor flyweight joint (12) by first turning flyweight assembly and then removing screw upwards. - Remove sliding bolt (11) from flyweight assembly (13).

11

12

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16.

Control lever Linkage lever Guide bolt Fulcrum lever Link Spring seat Clearance compensation spring Control rack Pressure ring Guide screw Sliding bolt Angular lever Flyweight Governor springs Setting nut Smoke limiter

Fig. 27. RQV governor

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GOV MEC_WSM_0001158_01

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