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Monochromelody

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  1. Tank You
    Monochromelody got a reaction from Zyklon in Transmissions and final drives   
    Share some less-known information about cold war period tracked vehicle transmission
     


    Mithubishi transmission MT75 for STB, later known as Type 74.
    The basic layout of MT75 is similar to the CD-500 transmission on M41 light tank, used by JGSDF in a short period after war.
    But the Japanese tank designers prefer mechanical gearbox rather than hydramatic gearbox, they use a electro-mechanic high-low range instead of a torque converter. The high-low range part is described as "1次変速"(range first stage).
    The steering mechanism is a single-radius, double differential type, operated by engaging steering clutch, also resemble the CD-500. 
     
    -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
     


     
    Allison X-700 transmission, a 800-hp class transmission to replace XTG-411 on T95 medium tank in 1960s. 
    Trials were successful but finally never adopted. The Army decided to develop a 1500-hp class transmission for XM803. 
    X-700 then evolved into X-1100 transmission. The X-200 and X-300 were basically smaller variants of X-700. 
    X-1100 users: M1 and its variants; Korean K9 "Thunder"; Turkish T-155 "Firtina"
    X-300 users: Warrior IFV; CV90 series
    X-200 users: M113 upgrade (A2 standard)
     
    -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
     


    Allison XHM-1500-B2, a hydrostatic-mechanical transmission developed in early 1970s. A competitor against X-1100 but less successful. 
    Different parts were shown in different color. 
    Orange: power input and forward-reverse shifting mechanism;
    Blue: hydrostatic-mechanical speed range (mechanical planetary gears were not shown in cutaway);
    Red: hydrostatic differential steering system; 
    Green: output shaft and planetary gears. 
     
     
    Hope you enjoy these pics. 
  2. Tank You
    Monochromelody reacted to heretic88 in Tank neutral steer capability   
    A ton of information here:
     
    http://otvaga2004.ru/na-zemle/na-zemle-1/bm-1945-1965_20/
  3. Tank You
    Monochromelody got a reaction from Molota_477 in Tank neutral steer capability   
    Another approach to neutral steering is the triple differential steering system. 
    Henry Edward Merritt, an engineer and gearbox designer, is famous for his unique invention, Merritt triple differential transmission. The first British mass production tank with triple differential transmission is the Churchill tank. 

    The Churchill tanks have a Merritt-Brown H4 gearbox, 4 stands for four gears forward, H stands for horizontal, because the two rows of gears in the gearbox are horizontally located. 
    A great advantage of Merritt's design is compactness. The transmission incorporate the range gears and steering mechanism into a single box, thus reduce the longitude size. The H4 transmission can provide four gears forward, one gear reverse, and a neutral position for neutral steer.
    The basic design itself is simple, but how to explain it could be a little bit difficult. Three differentials are arranged like this: 

    The left and right differentials are used for combining the driving power flow and steering power flow, and the steering differential is used for creating different speed of the steering gears. The bevel pinion gears are not easy to produce, so the design transformed into cylindrical gears. 

    ↑The Z5 gearbox on Cromwell cruiser tank
    When driving forward, the sun wheel and ring gear of planetary F1 and F2 always counter rotate. The carrier of F1 and F2 rotate on an average speed of the ring gear(forward) and the sun wheel(reverse), and because the ring gear rotates faster, the carrier rotates on the same direction with the ring gear, so the vehicle goes forward. 
    When steering brake J1 actuated, the sun wheel of F1 is stopped, now the carrier of F1 accelerate. The steering differential C then drives the sun wheel of F2 back rotate even faster(double time), so the carrier of F2 decelerate.
    When in a Cromwell/Centurion/Chieftain/Scorpion, the driver pulls right steering lever, which actuated the left steering brake, makes the track on left side go faster, the track on right side go slower, and the vehicle turns right. 

     
    Another important design feature of the H4/Z5 gearbox is the reverse gear. When reverse gear is selected, the main shaft(E) of the gearbox is locked and stopped. The main shaft is connected to the F1/F2 ring gear, so the ring gear is brought to a stop. F1/F2 sun wheel going reverse, driving the planetary carrier reverse. This design has advantages and disadvanteges. The advantage is that the gearbox doesn't need to insert a idler wheel between range gears to change the driving direction, thus ease the operation of gear changing. The disadvantage is that the reverse gear is very slow, due to the large reduction ratio. The reverse gear ratio of Z5 gearbox is approximately 22.894, makes the tank's reverse speed very slow. 
     
    When the vehicle is stopped on a solid plain terrain, and neutral position is selected, the planetary carrier stay still.  The sun wheels go reverse, bring the ring gear and main shaft rotates forward. Pull left steering lever, right sun wheel is stopped and forward-rotating ring gear bring the planetary carrier slowly forward, so the right track goes forward. The left sun wheel reverse double-time and faster than forward-rotating ring gear, bring the planetary carrier slowly reverse, thus the vehicle pivot in place. 
  4. Tank You
    Monochromelody reacted to heretic88 in Tank neutral steer capability   
    MTLB:
     

  5. Tank You
    Monochromelody got a reaction from Zyklon in Tank neutral steer capability   
    The neutral steer, or pivot steer, means the tank drive one track forward while the other track backward, to perform a turn-on-spot. 
    The very first tank with neutral steer, believe it or not, is the German A7V in WWI. 

    Here is the transmission of A7V. 

    The transmission incorporate two independent gearbox, each connected to a 100-hp engine. The gearbox use clash gears to select speed, and bevel gear to select forward or reverse. It's easy to perform a neutral steer. 
     
    Those tanks with electric transmission(St.Chamond, Porsche Tiger, etc.) can easily perform neutral steer, for their twin driving electric motors can rotate in opposite direction. And tanks with twin driving hydraulic motors(Panzer IV mit Hydrostatischem Antrieb) can neutral steer in a similar manner. 
     
    As mentioned above, the simplest way to neutral steer is to have seperated gearboxes or sub-transmissions driving both tracks. US airborne tank M551 Sherridan and Ukraine T-84 Oplot are modern approach of this manner. Althought they neutral steer with tracks driving in different speed, thus they cannot pivot steer precisely on the central spot. 


     
    The neutral steer capability is more common on dual-flow transmission. 
    A dual-flow transmission, or “双流传动” in Chinese, means the power flow from engine into the transmission splitted into driving power flow and steering power flow, then they join together with mesh gears or planetaries. Control these power flows allows the driver to change speed and steer left or right. 
     
    The dual-flow principle itself came up even earlier than the tank. The 1899 Vedovelli Priestley electric taxi equipped with double differential steering system, is capable of neutral steering. 

    And the first tank with dual-flow transmission is the Schneider-Renault SRB, then evolved into the Char B1 heavy tank. 


    The Char B1 tank's dual-flow principle is quite simple. The power splitted into two: the driving power flow into gearbox and drive the main differential; the steering power flow into the appareil Naëder, a hydrostatic pump-motor assembly, can rotate on different speed and direction. 

    Char B1 can use appareil Naëder to control its hull howitzer precisly, this principle inspired the Swedish Strv 103 tank. And the US M1 Abrams tanks use a HSU(Hydrostatic Steering Unit) based on the same principle of appareil Naëder. 

    (To be continued)
  6. Tank You
    Monochromelody reacted to heretic88 in Tank neutral steer capability   
    A lesser known fact is that certain soviet AFVs can also neutral steer, for example the MTLB and all its derivatives, and everything based on the GM-123 chassis, like SP Artillery or certain elements of the 2K11 Krug SAM system.
    Here a beautifully restored 2S3M, at 1:55
     
  7. Tank You
    Monochromelody got a reaction from heretic88 in Tank neutral steer capability   
    The neutral steer, or pivot steer, means the tank drive one track forward while the other track backward, to perform a turn-on-spot. 
    The very first tank with neutral steer, believe it or not, is the German A7V in WWI. 

    Here is the transmission of A7V. 

    The transmission incorporate two independent gearbox, each connected to a 100-hp engine. The gearbox use clash gears to select speed, and bevel gear to select forward or reverse. It's easy to perform a neutral steer. 
     
    Those tanks with electric transmission(St.Chamond, Porsche Tiger, etc.) can easily perform neutral steer, for their twin driving electric motors can rotate in opposite direction. And tanks with twin driving hydraulic motors(Panzer IV mit Hydrostatischem Antrieb) can neutral steer in a similar manner. 
     
    As mentioned above, the simplest way to neutral steer is to have seperated gearboxes or sub-transmissions driving both tracks. US airborne tank M551 Sherridan and Ukraine T-84 Oplot are modern approach of this manner. Althought they neutral steer with tracks driving in different speed, thus they cannot pivot steer precisely on the central spot. 


     
    The neutral steer capability is more common on dual-flow transmission. 
    A dual-flow transmission, or “双流传动” in Chinese, means the power flow from engine into the transmission splitted into driving power flow and steering power flow, then they join together with mesh gears or planetaries. Control these power flows allows the driver to change speed and steer left or right. 
     
    The dual-flow principle itself came up even earlier than the tank. The 1899 Vedovelli Priestley electric taxi equipped with double differential steering system, is capable of neutral steering. 

    And the first tank with dual-flow transmission is the Schneider-Renault SRB, then evolved into the Char B1 heavy tank. 


    The Char B1 tank's dual-flow principle is quite simple. The power splitted into two: the driving power flow into gearbox and drive the main differential; the steering power flow into the appareil Naëder, a hydrostatic pump-motor assembly, can rotate on different speed and direction. 

    Char B1 can use appareil Naëder to control its hull howitzer precisly, this principle inspired the Swedish Strv 103 tank. And the US M1 Abrams tanks use a HSU(Hydrostatic Steering Unit) based on the same principle of appareil Naëder. 

    (To be continued)
  8. Metal
    Monochromelody got a reaction from Mighty_Zuk in Tank neutral steer capability   
    The neutral steer, or pivot steer, means the tank drive one track forward while the other track backward, to perform a turn-on-spot. 
    The very first tank with neutral steer, believe it or not, is the German A7V in WWI. 

    Here is the transmission of A7V. 

    The transmission incorporate two independent gearbox, each connected to a 100-hp engine. The gearbox use clash gears to select speed, and bevel gear to select forward or reverse. It's easy to perform a neutral steer. 
     
    Those tanks with electric transmission(St.Chamond, Porsche Tiger, etc.) can easily perform neutral steer, for their twin driving electric motors can rotate in opposite direction. And tanks with twin driving hydraulic motors(Panzer IV mit Hydrostatischem Antrieb) can neutral steer in a similar manner. 
     
    As mentioned above, the simplest way to neutral steer is to have seperated gearboxes or sub-transmissions driving both tracks. US airborne tank M551 Sherridan and Ukraine T-84 Oplot are modern approach of this manner. Althought they neutral steer with tracks driving in different speed, thus they cannot pivot steer precisely on the central spot. 


     
    The neutral steer capability is more common on dual-flow transmission. 
    A dual-flow transmission, or “双流传动” in Chinese, means the power flow from engine into the transmission splitted into driving power flow and steering power flow, then they join together with mesh gears or planetaries. Control these power flows allows the driver to change speed and steer left or right. 
     
    The dual-flow principle itself came up even earlier than the tank. The 1899 Vedovelli Priestley electric taxi equipped with double differential steering system, is capable of neutral steering. 

    And the first tank with dual-flow transmission is the Schneider-Renault SRB, then evolved into the Char B1 heavy tank. 


    The Char B1 tank's dual-flow principle is quite simple. The power splitted into two: the driving power flow into gearbox and drive the main differential; the steering power flow into the appareil Naëder, a hydrostatic pump-motor assembly, can rotate on different speed and direction. 

    Char B1 can use appareil Naëder to control its hull howitzer precisly, this principle inspired the Swedish Strv 103 tank. And the US M1 Abrams tanks use a HSU(Hydrostatic Steering Unit) based on the same principle of appareil Naëder. 

    (To be continued)
  9. Tank You
    Monochromelody got a reaction from Lord_James in Name that AFV: The New Tank ID thread   
    From a Japanese magazine PANZER screenshot, it says: 
    This is a Type 61 tank with a sort of ad-hoc spaced armour, using for target practice in exercise. 
    The armour plates surrounding the turret and side skirts make it looks like a WW2 German Panzer IV. 
    The crew tried to pull out a practice round stucking in the side skirt, this round was fired from a recoilless rifle. 
    According to the vegetation of the exercise range, the vehicle was painted in a 4-colour camouflage. 
  10. Tank You
    Monochromelody got a reaction from Molota_477 in Name that AFV: The New Tank ID thread   
    From a Japanese magazine PANZER screenshot, it says: 
    This is a Type 61 tank with a sort of ad-hoc spaced armour, using for target practice in exercise. 
    The armour plates surrounding the turret and side skirts make it looks like a WW2 German Panzer IV. 
    The crew tried to pull out a practice round stucking in the side skirt, this round was fired from a recoilless rifle. 
    According to the vegetation of the exercise range, the vehicle was painted in a 4-colour camouflage. 
  11. Tank You
    Monochromelody reacted to DarkLabor in French flair   
    https://imgur.com/a/rvwc31g

    Well the history of the AMX 10 program is quite complicated (at least for the AMX 10 RC).
    At first (1960) it was planned to have an all tracked family with the ERAC (Engin de Reconnaissance Amphibie Chenillé == Tracked Amphibious Reconnaissance Vehicle) as a recce vehicle with a 90mm gun fitted in an oscillating turret. Studies were pushed towards a 105mm gun system with an ongoing competition between the APX and the EFAB engineers teams for the ammunition. The ERAC was dropped when the specifications were more demanding and other weapon systems were considered. The ECA (Engin de Combat Amphibie == Amphibious Fighting Vehicle) did not last long (mid 60s) but was considered with a wide range of weapon systems ranging from conventional 105mm gun to conventional anti-tank missile with the tube launched ACRA missile system inbetween.
    In the end, the development of the AMX 10 P seems to be uneventful compared to the AMX 10 RC which ended up being based on the AMX 10 P in order to reduce possession cost and ease of maintenance.
  12. Tank You
    Monochromelody reacted to Serge in French flair   
    Hi. 
    I’m not skilled enough to answer you. I was tank commander on AMX-10RC, but it was a long time ago. And user are not always the best historians. Today, I’m much more sharper on the tactical side of the Force. I now if things are useless or useful. 
     
    If you have questions about the deployment and the use, don’t hesitate...
     
    Visite this French site :
    http://www.chars-francais.net/2015/index.php
    It’s no more active but this is the best place ever to find photos of all the French AFV produced (even as prototypes only).
    Use Google to search into because pages with the list of AFV per decades. 
    Search for :
    - AMX10 RTT, C, ACRA, P, PH (improved P).
     
    Send MP to @DarkLabor. He’s up to date in French doc. Maybe @Sovngard can help.
  13. Tank You
    Monochromelody reacted to Serge in French flair   
    Thank you. 
    I didn’t know about the ERAC. 
  14. Tank You
    Monochromelody reacted to Serge in French flair   
    During the late 70’s, an attempt was made to use the AMX-10P as a light recce tank, the AMX-10C :

     

     
    A wheeled chassis was preferred as the successor of the EBRC. This is the AMX-10RC.

    An APC/IFV version was available : the AMX-10RTT wich never found any customers. 

     
    An interesting concept was the Mars-15 family :

     

    It was introduced in 1987 as a successor of the AMX-13 for export market by Creusot-Loire Industrie (It was specifically designed to be produced by the customer’s industry.).
    In 1990, when CLI was purchased by GIAT Industries, it was killed. The latter considered it wasn’t possible to promote simultaneously a light tracked AFV family for export market, and the idea that wheeled AFV can performed as tracked one for the French Army.
    We have to remind it was forbidden by the 90’s, to talk about any tracked solution to succeed to the old AMX-10PH (even if the purchase of CV90 was considered in case of Leclerc MBT victory in the Swedish market.).
  15. Tank You
    Monochromelody got a reaction from Scolopax in Name that AFV: The New Tank ID thread   
    According to Rolf Hilmes' KPz Leopard 1 1956-2003, p.43, 
    In year 1983, the Bundeswehr send two Leopard 1 tanks for 120 mm cannon conversion: one Leopard 1 A5 with cast turret, one Leopard 1 A3 with welded turret. 

    And in Tankograd No.5014, p.30, 
    The conversion of normal Leopard 1 A5 also included the preparation for installation of a 120mm smoothbore cannon, though never realised in production models. 
  16. Funny
    Monochromelody got a reaction from AdmiralTheisman in Main Ground Combat System (MGCS) and Euro Main Battle Tank (EMBT)   
    direct ancestor of EMBT
  17. Tank You
    Monochromelody got a reaction from Akula_941 in Tank “document” misleading   
    各位最近可能在WT论坛上见过这张图片,在一些争论陆上自卫队90式战车的讨论串里:
    Some of you may have seen this pic recently on WT forum, in some thread arguing the protection of JGSDF Type 90: 
    Discussion on WT forum
     

     
    我就直说吧,表格里的中文注解说了,这不过是个“猜想”,GUESSING。
    To be straight, the Chinese annotation in the table said it is just a GUESSING.
    注解内容可能完全是编造的,但不幸的是,不同语言间的障碍使你们无法看穿这点。
    This annotation could be totally nonsense but unfortunately a barrier between languages prevent you guys see throught it. 
     
    实际上,这又是一份关于陆上自卫队10式战车的文件,说的并不是90式。
    In fact, again, this document itself is about JGSDF Type 10 MBT, not Type 90.
    同样的花招,不一样的人,是吧?
    Same trick, different people, huh?

    ↑陆上自卫队的10式战车规格书
    JGSDF specification handbook of Type 10 MBT

    ↑59页,附录B,性能(规定)以及诸元
    page 59, Appendix B, performance (regulations) and data
     
    下面简要说说这些性能规定如何编写、如何加密。
    Let's talk about these regulations and how they were made and encrypted. 
     
    大家可能知道日语中有平假名和片假名,和拉丁语中的字母还有大写字母是差不多的。
    You may know that Japanese have Hirakana and Katakana, like Latin have letters and capital letters. 
     
    正如图中所示,一些最关键的数值和描述用平假名、片假名、罗马字(拉丁字母)隐去了。
    As you can see, some of the most crucial numbers and descriptions are covered by a Hirakana or Katakana or Romaji(Latin letters).
     
    这些数值和描述被归在一起,编入附属的手册,称为“别册”。
    These numbers and descriptions were collected and listed in some append book, called Bessatsu(別冊). 
     
    在查阅别册时,就好比在看试卷的答题卡。但如果把别册里面的数值和描述涂黑,你就根本不知道说啥。
    When you look up to the append book, just like viewing the answer sheet of an exam paper. But when numbers and descriptions were censored, you'll never know what it said. 
     
    比如说,正面防护:
    For example, the frontal protection: 
     
    “耐弾性 - 正面 - 正面要部は、【あ】に射距離【え】m相当存速において、貫徹されない。”
     
    读起来是这样的:
    耐弹性 - 正面 - 正面重要部位可抵御【あ】以相当于射击距离【え】米存速的射击,不会贯穿。
    It read like this: 
    Protection - Frontal - Frontal crucial part should withstand 【あ】 firing at a distance of 【え】meter speed reduce equivalent, and not penetrate. 
     
    【あ】代表某种弹药,可能是尾翼稳定穿甲弹,但不知道是量产弹种还是实验弹种。
    【あ】stands for certain type of ammunition, probably APFSDS, but don't know whether it is production shot or experimental.
     
    【え】代表某个射击距离,可以是1000、1500或2000(米),但这么远的距离,炮弹会受到风力和重力影响,故无法精确瞄准靶车的防护区域。
    【え】stands for certain firing distance, could be 1000 , 1500 or 2000 (meters), but on such a long distance, shot could be effect by wind and gravity, thus cannot aim on the protection area of target vehicle precisely.
     
    一个常见的解决方式是在更近的距离上开火,比如说200到550米,同时减少推进药量,使得穿甲弹的终点速度符合特定距离的速降。这是一种等效方法。
    The usual solution is to fire from a much closer range, from 200 to 550 meters, while reducing the propellant charge so that the end speed of AP shot could match the speed drop on certain distance. This is an equivalant method. 
     
    有的人争辩说90式战车可以抵挡另一辆90式战车发射的穿甲弹(JM33),距离大约250米。这一说法源自一段未知视频片段,具体什么视频他们自己也没看过。较近的射击距离是为了能更好的瞄准,为此可能使用了减装药来模拟远距离终点速度,但也无法证明。
    Some people argue that Type 90 MBT can withstand AP shot (JM33) firing from another Type 90 MBT, on a distance about 250 meters. The source of this statement came from an unknown video clip, which they have never seen. Firing on closer range is for better aim, and they could have use reduced charge to simulate a much longer range, but we cannot prove. 
     
     
  18. Tank You
    Monochromelody got a reaction from Karamazov in Main Ground Combat System (MGCS) and Euro Main Battle Tank (EMBT)   
    That's an AMX 30 prototype(1961)

  19. Metal
    Monochromelody reacted to DarkLabor in [Question] About AMX 10 RC transmission   
    Not stacked with technical documentations on the AMX 10 RC but maybe that one will help you :


  20. Tank You
    Monochromelody got a reaction from DarkLabor in [Question] About AMX 10 RC transmission   
    Thanks a lot! 
    It appears to be a triple-differential steering system. 
     
  21. Funny
    Monochromelody got a reaction from Xlucine in Main Ground Combat System (MGCS) and Euro Main Battle Tank (EMBT)   
    direct ancestor of EMBT
  22. Metal
    Monochromelody got a reaction from Molota_477 in Main Ground Combat System (MGCS) and Euro Main Battle Tank (EMBT)   
    That's an AMX 30 prototype(1961)

  23. Metal
    Monochromelody got a reaction from Karamazov in Main Ground Combat System (MGCS) and Euro Main Battle Tank (EMBT)   
    direct ancestor of EMBT
  24. Metal
    Monochromelody got a reaction from Serge in Main Ground Combat System (MGCS) and Euro Main Battle Tank (EMBT)   
    direct ancestor of EMBT
  25. Funny
    Monochromelody got a reaction from Molota_477 in Main Ground Combat System (MGCS) and Euro Main Battle Tank (EMBT)   
    direct ancestor of EMBT
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