WATER PUMP BEARINGS 
          As the automobile's core ,the engine is improving with high efficiency, so to the water pump bearing, we need more high requirements, for example, more load,
     and more high anti-heat, and better seal.
                   RTL-water pump bearing is that new style of bearing fitting for these requirements. In the fact, it is a kind of simple double-load bearing. The double-load bea-
     ring has no inner ring, the race-way of roller is on the shaft directly. The two load bearing forms a whole , both side of the outer ring sealed with seal . At the same load 
     condition, the size of radial load is smaller than other bearings. And the same axial load condition, the ability of load is high than other bearings . Because of good-hard ,
     high accuracy of rotate, simple structure, and easy dismounting, many countries, like AMERICA, JAPAN, and GERMAN all use this kind of structure. RTL develops
     all kinds of water pump bearing and they are used in automobiles that made in our China.
                   Water pump is formed by outer ring, water pump bearing, anti-water seal, impeller, fan and rollers.  water pump bearing is the most important part of the water
     pump. Because the high speed of revolution, usually it reaches 9000r/min, it requires  the high-load ability of  water pump bearing. And only this can guarantee the life of 
     bearing under the high speed revolution. Because of the limited space, bad operation condition, the  water pump bearing should assure the normal revolution requirement, 
     and the same time can decrease the bearing's ability of load. It  is difficult for the seal of bearings , beacuse the reliability and the wear ability of the bearing will effect the
     usage of the bearing. Totally, loading ability, operating seal and operating clearance, are the importand factors effecting the capability of the bearing.

The range of products

 

n         WB            

double-row ball water pump spindle bearing

n         WR            

simple-row ball and simple roller water pump spindle bearing

n         WB...C      

double-rowballwater pump spindle(angular contact)

n         WR...C     

simple-row ball and simple roller water pump spindle bearing(Four-point angular contact)

Usually, WR and WB can satisfy the most of loading requirements. Only under some special condition, the inner structure will be designed as the high-hardness, like WB...C and W...C series water pump bearing.

 

Material and heating treatment
The ball and the roller of RTL are all made by high chrome steel, and shaft, outer ring uses carbon steel or chrome steel. Usually, if the shaft material is high-carbon, the hardness reaches 60-64HRC. And if the shaft material is high-chrome, the hardness reaches 58-62HBC. The hardness of ball and roller reaches 61-65HRC. And the hardness of outer ring is 60-64HRC.

Lubrication and Seal

 
              RTL water pump bearing use once-time lubrication and also it is a kind of lifetime lubrication. It is normal for a small
 quality of grease to come out of the seal lip.This quality should be 1/4 or 1/2 part of the space. In usual condition, NO 2# or
 NO 3# grease can satisfy the requirement of lubrication, but when the temperature is higher than 120℃.We should use high-level
 grease.
       The function of the waterpump bearing seals is to exclude contaminants,such as dust or coolant vapour,while retaining the
 lubricant.It is normal for a small quantity of grease to come out of the seal lip,as part of the lubrication of the seal lip 
 interface.This quantity should not exceed 0.2g.The seal performance is determined by thematerial properties and the lip design,
 as detailed below. 

Conventional single lip snap type design

1.For normal automotive applications
2.Vulcanized elastomer sealing element
3.Ease of assembly
4.Economical

Standard double lip interlocking design

1.For demanding applications
2.Inward facing seal lip for improved grease retention
3.Upgraded rubber material for better sealing against coolant
4.Positive lock in outer ring,reduces possibility of seal spinning
5.Optimized lip cross-section for torque and sealing performance

Triple lip interlocking design

1.For severe applications
2.Inward facing seal lip for improved grease retention
3.Upgraded rubber material for better sealing against coolant
4.Positive lock in outer ring,reduces possibility of seal spinning
5.Optimized lip cross-section for torque and sealing performance
6.Additional stainless steel slinger and third lip for increased sealing potrction

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Clearance

 
        The intenal bearing clearance in rolling bearings in operation greatly influences bearing performance in terms of fatigue life ,
  vibration ,noise,heat-generation ,ect. Conaequently ,theselection of a proper internal clearance is one of the most important tasks .
  Theoretically,the longeat bearing life can be expected when the clearance is slightly negative.However ,it is difficult to achievesuch
  an ideal condition,and an excessive negative clearance will greatly shorten the bearing life.Therefore,a clearance of zero ora slightht 
  positive amount,instead of a negative one ,should be selected in general.
        When choosing the clearance, we should not only consider the decrease of the clearance, because of the interference fit between 
  the outer ring and bearing    seating, but also should consider the decrease of the clearance, because of the increasing of the tempe-
  rature. The shell of the water pump bearing has two    kinds of shell, one is iron, another is aluminum. The fit of the water pumpbear-
  ing and shell is interference fit (For list one). 
        RTL bearing has no special requirements. The radial clearance is 15-35μm. NSK water pump bearing's radial clearance is 10-40μm. 
  FAG is 10-36μm.

轴承外径D

泵壳内径偏差(μm)

iron

aluminum

--24

-27-- -48

-46-- -67

 

24--30

-33-- -53

-56-- -77

 

30--52

-34-- -59

-71-- -96

 

 

Accuracy

The tolerance of water pump bearing needs to satisfy with LIST TWO.
The coarseness of water pump bearing needs to satisfy with LIST THREE.
The accuracy of revolution is not more than 0.025mm.

表2    轴连轴承的尺寸公差(μm)。

外

套

圈

D(mm)

△ Dmp

VDP

VDmp

△Cs

VCs

超过

到

上偏

差

下偏

差

最大

最大

上偏

差

下偏

差

最大

18

30

0

-11

12

8

0

-250

20

30

50

0

-13

16

10

0

-250

20

50

80

0

-15

20

11

0

-250

20

轴

D(mm)

△ Dmp

VDP

VDmp

△Cs

超过

到

上偏

差

下偏

差

最大

最大

上偏

差

下偏

差

10

18

0

-11

8

8

0

-500

18

30

0